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Sample records for radioactivite rayonnements ionisants

  1. Biological Effects of Ionising Radiation and Countermeasures (Les effets biologiques des rayonnements ionisants et leurs contre-mesures)

    2018-01-01

    radiation physicists. As an example, a special issue of Health Physics [3] presents a body of experimental work characterizing the outdoor...Terrorist Attack involving Ionising Radiation. Campus Vesta, Belgium September 25-29, 2016. [3] Health Physics (Special Issue) 2016:110;399- 547...of Radiobiology & Radiation Protection 128 Szaserów Street 04-141 Warsaw POLAND Email: mjaniak@wihe.waw.pl Mr. Tjerk KUIPERS Health Physics

  2. Calculs de doses générées par les rayonnements ionisants principes physiques et codes de calcul

    Vivier, Alain

    2016-01-01

    Cet ouvrage et les codes associés s’adressent aux utilisateurs de sources de rayonnements ionisants : techniciens, ingénieurs de sécurité, personnes compétentes en radioprotection, mais aussi médecins, chercheurs, concepteurs, décideurs… Les contraintes croissantes liées à la radioprotection rendent indispensables l’utilisation de codes de calcul permettant d’évaluer les débits de doses générées par ces sources et la façon dont on peut s’en protéger au mieux. De nombreux codes existent, dont certains restent des références incontournables, mais ils sont relativement complexes à mettre en oeuvre et restent en général réservés aux bureaux d’études. En outre, ces codes sont souvent des « boîtes noires » qui ne permettent pas de comprendre la physique sous-jacente. L’objectif de cet ouvrage est double : - Exposer les principes physiques permettant de comprendre les phénomènes à l’oeuvre lorsque la matière est irradiée par des rayonnements ionisants. Il devient al...

  3. The study of some thiazinic and indaminic dye syntheses induced by ionising radiation; Etude de quelques syntheses de colorants thianziniques et indaminiques amorcees par les rayonnements ionisants

    Balestic, S [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-03-15

    grace a leur spectre d'absorption apres qu'ils aient ete separes du milieu reactionnel par chromatographie d'adsorption ou d'echange d'ions; d'autres produits de la radiolyse, chlorure d'ammonium et eau oxygenee, ont ete egalement caracterises. Au cours d'une etape ulterieure, une variation systematique des parametres physico-chimiques a permis de determiner les conditions les plus favorables a la radiosynthese; les rendements radiochimiques maximum obtenus ont pour valeurs respectives: G (Violet de Lauth) = 1,65; G (Bleu de Methylene) = 1,75. En outre, l'etude de l'influence sur le rendement radiochimique des reactifs amines differemment substitues a fait apparaitre la possibilite de synthetiser par voie radiochimique le Vert de Bindschedler et le Bleu de Wurster. Enfin la decouverte d'un compose intermediaire fondamental, le Rouge de Wurster, ainsi que l'etude cinetique de la synthese chimique du Bleu de Methylene ont permis de determiner les principales etapes du Bleu de Methylene reactionnel et de preciser la part qui revenait aux rayonnements ionisants dans le cas de la synthese par voie radiochimique. (auteur)

  4. Thermoluminescent properties of CVD diamond: applications to ionising radiation dosimetry; Proprietes thermoluminescentes du diamant CVD: applications a la dosimetrie des rayonnements ionisants

    Petitfils, A

    2007-09-15

    Remarkable properties of synthetic diamond (human soft tissue equivalence, chemical stability, non-toxicity) make this material suitable for medical application as thermoluminescent dosimeter (TLD). This work highlights the interest of this material as radiotherapy TLD. In the first stage of this work, we looked after thermoluminescent (TL) and dosimetric properties of polycrystalline diamond made by Chemically Vapor Deposited (CVD) synthesis. Dosimetric characteristics are satisfactory as TLD for medical application. Luminescence thermal quenching on diamond has been investigated. This phenomenon leads to a decrease of dosimetric TL peak sensitivity when the heating rate increases. The second part of this work analyses the use of synthetic diamond as TLD in radiotherapy. Dose profiles, depth dose distributions and the cartography of an electron beam obtained with our samples are in very good agreement with results from an ionisation chamber. It is clearly shown that CVD) diamond is of interest to check beams of treatment accelerators. The use of these samples in a control of treatment with Intensity Modulated Radiation Therapy underlines good response of synthetic diamond in high dose gradient areas. These results indicate that CVD diamond is a promising material for radiotherapy dosimetry. (author)

  5. Contribution to the study of the ionization and heating of gases by laser radiation; Contribution a l'etude de l'ionisation et du chauffage des gaz par le rayonnement d'un laser declenche

    Veyrie, P [Commissariat a l' Energie Atomique, Limeil-Brevannes (France). Centre d' Etudes

    1968-01-01

    The ionization and heating of gases by the concentrated radiation of a neodymium laser is studied. The power is 300 MW, the gas studied is primarily deuterium between 300 mm and 2280 mm. The first part concerns a certain number of experimental results on the absorption of the radiation and on changes produced in the plasma as a function of time. From these results are deduced a certain number of consequences, amongst which may be mentioned the definition of a pre-ionization threshold. These experimental results are interpreted in the second part. A calculation is made of the length of the period during which the electrons multiply up to when the absorption becomes measurable. The last phase corresponds to the hydrodynamics evolution, the calculations are compared with the experiments. The agreement between theory and experiment is satisfactory for the different phases. (author) [French] On etudie l'ionisation et le chauffage des gaz par le rayonnement concentre d'un laser au neodyme. La puissance est de 300 MW, le gaz etudie est principalement le deuterium entre 300 mm et 2280 mm. La premiere partie concerne un certain nombre de resultats experimentaux. Il s'agit de l'absorption du rayonnement et de l'evolution chronologique du plasma. De ces resultats on deduit un certain nombre de consequences parmi lesquelles il faut citer la definition d'un seuil de preionisation. Ces resultats experimentaux sont interpretes dans la deuxieme partie. On calcule la duree de la phase pendant laquelle se multiplient les electrons jusqu'a ce que l'absorption soit mesurable. La derniere phase correspond a l'evolution hydrodynamique. Les calculs sont confrontes avec l'experience. L'accord entre theorie et experience est satisfaisant pour les differentes phases. (auteur)

  6. Contribution to the study of the ionization and heating of gases by laser radiation; Contribution a l'etude de l'ionisation et du chauffage des gaz par le rayonnement d'un laser declenche

    Veyrie, P. [Commissariat a l' Energie Atomique, Limeil-Brevannes (France). Centre d' Etudes

    1968-01-01

    The ionization and heating of gases by the concentrated radiation of a neodymium laser is studied. The power is 300 MW, the gas studied is primarily deuterium between 300 mm and 2280 mm. The first part concerns a certain number of experimental results on the absorption of the radiation and on changes produced in the plasma as a function of time. From these results are deduced a certain number of consequences, amongst which may be mentioned the definition of a pre-ionization threshold. These experimental results are interpreted in the second part. A calculation is made of the length of the period during which the electrons multiply up to when the absorption becomes measurable. The last phase corresponds to the hydrodynamics evolution, the calculations are compared with the experiments. The agreement between theory and experiment is satisfactory for the different phases. (author) [French] On etudie l'ionisation et le chauffage des gaz par le rayonnement concentre d'un laser au neodyme. La puissance est de 300 MW, le gaz etudie est principalement le deuterium entre 300 mm et 2280 mm. La premiere partie concerne un certain nombre de resultats experimentaux. Il s'agit de l'absorption du rayonnement et de l'evolution chronologique du plasma. De ces resultats on deduit un certain nombre de consequences parmi lesquelles il faut citer la definition d'un seuil de preionisation. Ces resultats experimentaux sont interpretes dans la deuxieme partie. On calcule la duree de la phase pendant laquelle se multiplient les electrons jusqu'a ce que l'absorption soit mesurable. La derniere phase correspond a l'evolution hydrodynamique. Les calculs sont confrontes avec l'experience. L'accord entre theorie et experience est satisfaisant pour les differentes phases. (auteur)

  7. Dégradation de lŽADN par les rayonnements ionisants. Influence de la structure et de lŽenvironnement

    Maurizot, M.; Běgusová, Marie

    11-12 (2003), s. 97-102 ISSN 0151-9093 R&D Projects: GA AV ČR IAA1048103 Institutional research plan: CEZ:AV0Z1048901 Keywords : DNA * ionising radiations * hydroxyl radical Subject RIV: BO - Biophysics Impact factor: 0.112, year: 2003

  8. Collection efficiency of charges in ionization chambers in presence of constant or variable radiation intensity; Efficacite de la collection des charges dans les chambres d'ionisation en presence d'une intensite de rayonnement ionisant constante ou variable

    Decuyper, J [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1970-07-01

    The theoretical and experimental study of the collection of carriers built up by ionization in standard chambers, is made by varying the value of different acting parameters. In the presence of constant ionization intensity and under a D.C. and A.C. voltage, the effect of geometry, recombination, diffusion and attachment is analyzed. The compensation of thermal neutron D.C. chambers is equally considered. Under a time dependent ionization intensity and D.C. voltage, is then studied the effect of recombination on current response, and on the collection efficiency of all formed charges. (author) [French] L'etude theorique et experimentale de la collection des porteurs crees par ionisation dans les chambres couramment utilisees est entreprise en fonction de la valeur des differents parametres agissants. En presence d'une ionisation constante et sous une tension d'alimentation d'abord continue puis alternative, on analyse l'influence de la geometrie, de la recombinaison, de la diffusion et de l'attachement. La compensation des chambres a courant continu de mesure neutronique est egalement examinee. Ensuite, sous une intensite d'ionisation variable dans le temps et en alimentation continue, on etudie l'effet de la recombinaison sur la reponse en courant et sur l'efficacite de la collection de la charge totale liberee. (auteur)

  9. Effects of Ionizing Radiation on Insects and Other Arthropods; Effet des rayonnements ionisants sur les insectes et autres arthropodes; Vozdejstvie ioniziruntsej radiatsii na nasekomykh i drugikh chlenistonogikh; Efectos de las radiaciones ionizantes sobre los insectos y otros artropodos

    Stone, William E. [United States Department of Agriculture Laboratories, Mexico City, D.F (Mexico)

    1963-09-15

    -Star tick, Amblyomma americanum L., and ionizing radiation as a possible quarantine treatment for fruits and vegetables infested with fruit flies and mangoes infested with the mango weevil, Sternochetus mangiferae Fabricius, are also discussed. (author) [French] Des recherches sur la possibilite d'appliquer la methode de sterilization par les rayonnements pour l'eradication de populations d'insectes sont actuellement en cours pour un certain nombre d'insectes nuisibles a l'homme, aux animaux et a diverses cultures. Il ressort de ces recherches preliminaires que les rayonnements ionisants provoquent la sterilite, mais que les doses necessaires varient considerablement. Ces recherches donnent aussi a penser que les dommages radioinduits sont tels qu'il ne serait pas opportun d'appliquer cette methode a toutes les especes d'insectes. Une difficulte a laquelle on se heurte frequemment est l'absence de methodes pratiques d'elevage en masse. D'autre part, certaines populations d'insectes sont tellement nombreuses qu'il peut etre impossible de recourir a cette methode sans avoir au prealable applique dans la region infestee d'autres methodes de lutte de maniere a pouvoir atteindre les populations naturelles. Malgre ces difficultes, si les conditions sont favorables, il existe peu d'autres methodes qui puissent donner d'aussi bons resultats. On peut aussi envisager de recourir a la methode de sterilisation par les rayonnements pour retarder la pullulation des insectes jusqu'a la moisson des recoltes. Le memoire rend compte de l'influence des rayons gamma sur la capacite de reproduction, l'agressivite sexuelle, la vigueur et la longevite de divers insectes: mouche orientale des fruits Dacus dorsalis Hendel, mouche du melon Dacus cucurbitae Coq., mouche mediterraneenne des fruits Ceratitis capitata Wied, mouche mexicaine des fruits Anastrepha ludens Loew et Anopheles quadrimaculatus Say; il donne aussi les resultats d'experiences reelles de lacher de males steriles pour l

  10. Design and test of a scintillation dosimeter for dosimetry measurements of high energy radiotherapy beams; Conception et realisation d'un dosimetre a scintillation adapte a la dosimetrie de faisceaux de rayonnements ionisants en faisceaux de rayonnements ionisants en radiotherapie

    Fontbonne, J.M

    2002-12-01

    This work describes the design and evaluation of the performances of a scintillation dosimeter developed for the dosimetry of radiation beams used in radiotherapy. The dosimeter consists in a small plastic scintillator producing light which is guided by means of a plastic optical fiber towards photodetectors. In addition to scintillation, high energy ionizing radiations produce Cerenkov light both in the scintillator and the optical fiber. Based on a wavelength analysis, we have developed a deconvolution technique to measure the scintillation light in the presence of Cerenkov light. We stress the advantages that are anticipated from plastic scintillator, in particular concerning tissue or water equivalence (mass stopping power, mass attenuation or mass energy absorption coefficients). We show that detectors based on this material have better characteristics than conventional dosimeters such as ionisation chambers or silicon detectors. The deconvolution technique is exposed, as well as the calibration procedure using an ionisation chamber. We have studied the uncertainty of our dosimeter. The electronics noise, the fiber transmission, the deconvolution technique and the calibration errors give an overall combined experimental uncertainty of about 0,5%. The absolute response of the dosimeter is studied by means of depth dose measurements. We show that absolute uncertainty with photons or electrons beams with energies ranging from 4 MeV to 25 MeV is less than {+-} 1 %. Last, at variance with other devices, our scintillation dosimeter does not need dose correction with depth. (author)

  11. Simplified Procedures for Obtaining Clearances of Foods Preserved by Ionizing Energy; Procedures Simplifiees pour Obtenir l'Autorisation de Produire des Denrees Alimentaires Conservees par les Rayonnements Ionisants; Uproshennaya protsedura polucheniya razreshenij na prodazhu obluchennk pishchevykh produktov; Simplificacion de los Procedimientos para la Obtencion de Autorizaciones de Venta de Alimentos Conservados Mediante Radiaciones Ionizantes

    Josephson, E. S. [United States Army Natick Laboratories, Natick, MA (United States)

    1966-11-15

    After thirteen years of intensive research, using high doses of ionizing energy, highly acceptable wholesome shelf-stable bacon, ham, pork, beef, chicken and shrimp can be produced in the laboratory. Using doses below 1 Mrad, the shelf life of highly acceptable wholesome fish, wheat and wheat products, oranges, and white potatoes can be extended. Before production in the United States can be scaled up to commercial quantities for the broad consumer market, approvals are required from the United States Food and Drug Administration (USFDA) and, for meats from mammals and birds, from the United States Department of Agriculture (USDA). These agencies have approved bacon, wheat and wheat products, and white potatoes, following receipt and evaluation of petitions containing all pertinent information including description of the process to be used and the food-package combination to be cleared, the proposed radiation source, the dose range, dosimetry methods, wholesomeness and nutritional data, positive proof of microbiological safety, absence of measurable induced radioactivity, acceptance data from taste panelists, and storage and shipping data where applicable. Collecting the data required for successful petitions has proved to be both time-consuming and expensive. To improve this situation, the whole process of data collection and of writing the petitions is being reexamined in the interest of streamlining and expediting the process. Recommendations are offered relative to some of the means helpful in achieving this end. (author) [French] Apres treize ans de recherches intensives au moyen de fortes doses de rayonnements ionisants, il est maintenant possible de produire en laboratoire. des denrees - lard, jambon, viande de porc etdeboeuf, poulet, crevettes - se conservant bien et de comestibilite tout a fait satisfaisante. En utilisant des doses inferieures a 1 Mrad, il est possible de prolonger la duree de conservation du poisson, du ble et derives, des oranges et des

  12. High-Dose Ionizing Radiation Photographic Dosimetry; Mesure, par des Methodes Photogra Phiques, de Doses Elevees de Rayonnements Ionisants; 0424 041e 0422 041e 0413 0420 0414 ; Dosimetria Fotografica de Dosis Elevadas de Radiaciones Ionizantes

    Trousil, J.; Bucina, I. [Institute for Research Production and Application of Radioisotopes Prague, Czechoslovakia (Czech Republic)

    1965-06-15

    energy dependence and latent image fading on the accuracy of exposure measurement was determined. Finally the errors in film dosimetry of high-level doses, which were observed on,the basis of experimental work with the aid of mathematical statistics, are described. The increase over the error in the range of little and severe blackening is also considered. The errors associated with calibration, energy dependence, latent image fading, chemical processing and measurement of blackening are also taken into account. The error associated with the assumption that the dose assessed by the film badge corresponds to the whole-body dose is not considered. (author) [French] Les auteurs decrivent une methode photographique de mesure de doses de rayonnements comprises entre 10 mr et 1000 r (rayons gamma et rayons X de haute energie). Cette methode comporte l ' emploi de deux films a emulsions differentes, qui sont montes dans un meme boitier. Cette methode a pour caracteristique essentielle de permettre d' evaluer les doses comprises dans les limites indiquees ci-dessus sans savoir s' il y a eu exposition a une dose plus elevee, avec une precision superieure a {+-}25% dans toute l'etendue de mesure (fidelite de 95%); elle permet aussi d'evaluer de maniere assez approchee l'energie des rayonnements auxquels le film a ete expose. Le memoire traite des appareils, types de films et traitements chimiques qui rendent ces mesures possibles. Il decrit le principe de la construction d'un densitometre qui permet de mesurer avec la meme precision le noircissement du film dans une gamme allant de D = 0 a D = 6. Il est ainsi possible de tirer parti de toute la region ou le noircissement du film peut etre employe. Etant donne qu'aucun photomultiplicateur n' est utilise, les possibilites de surexposition sont reduites au minimum et l'appareil peut donc etre utilise pour les mesures normales. Le memoire indique egalement les caracteristiques que les films dosimetres doivent avoir pour etre utilises

  13. Functional modifications of the enteric nervous system following radiation exposure: short and long term effects; Modifications du fonctionnement du systeme nerveux enterique suite a une exposition aux rayonnements ionisants: effets precoces et a long terme

    Ropenga, A

    2003-09-15

    Exposure of the gastrointestinal tract to ionising radiation induces at short or at long term, digestive dysfunctions, including nausea, diarrhoea, constipation and eventually abdominal pain. The mechanisms implicated remain incompletely understood, but may involve at long term functional modifications of the enteric nervous system (ENS). The mediator 5-Hydroxytryptamine (5-HT, serotonin) is present in entero-chromaffin cells and the ENS and plays an important role in digestive functions. The aim of this work was to follow between 3 days and 3 months after an hemi-body irradiation (10 Gy, X rays) radiation-induced modifications of 5-HT content, 5-HT receptor expression and effects on electrolyte movement in rat distal colon. At 3 days following irradiation, a reduction of total epithelial cells was observed along with a diminution of 5-HT transporter expression. Receptors 5-HT{sub 1A} and 5-HT{sub 2A} expression was diminished concomitant with a reduced response to 5-HT or neural stimulation and an increased importance of the receptor 5-HT{sub 3}. At 7 days crypt total cell number was increased and the importance of receptors 5-HT{sub 2A} and 5-HT{sub 3} in the secretory response was also increased. At later times, between 28 and 43 days, irradiation increased mucosal 5-HT content. This increase can be related to an increase of the number of entero-chromaffin cells at 28 days and is concomitant with the diminution of the importance of the receptor 5-HT{sub 2A} in the secretory response. In conclusion, this project has established for the first time differential expression of 5-HT receptors in the mucosal and muscle layers in the distal colon. Moreover, irradiation induces modifications in 5-HT receptor expression and importance in secretory epithelial responses. Irradiation also disturbs the equilibrium of different cell types by the epithelium in increasing the number of entero-chromaffin cells containing 5-HT. (author)

  14. Effects of Incorporated Radioactivity and External Radiation on Heterogeneous Catalysis; Effets de la radioactivite incorporee et des rayonnements externes sur la catalyse heterogene; Vliyanie vvedennoj radioaktivnosti i vneshnego oblucheniya na geterogennyj kataliz; Efectos de la radiactividad incorporada y de la irradiacion externa sobre la catalisis heterogenea

    Krohn, N. A.; Wymer, R. G. [Oak Ridge National Laboratory, Oak Ridge and University of Tennessee, Knoxville, Tennessee (United States)

    1963-11-15

    {sub 3} - Al{sub 2}O{sub 3} active. Ils ont fait des recherches sur les effets de l'incorporation de radioisotopes dans les catalyseurs et d'une exposition prealable aux rayons gamma du cobalt-60. Les catalyseurs au sulfate de magnesium et au sulfate double de magnesium et de sodium contenant jusqu'a 45,5 mc de {sup 35}S par gramme etaient moins actifs que les catalyseurs non radioactifs de composition analogue si on les comparait par unite de surface. La reduction de l'activite catalytique persistait meme apres qu'une desintegration importante se fut produite. En outre, on n'a pas observe de changements de l'activite catalytique sous exposition a des rayons X au cours de la reaction. On en conclut que l'emission de particules beta par le catalyseur au cours de son emploi est sans effet. Les resultats faisant etat d'une augmentation de l'activite catalytique peuvent etre attribues au fait que pour des conditions donnees de preparation, les catalyseurs radioactifs ont une plus grande surface que leur correspondants non radioactiis et qu'on n'avait pas tenu compte de ce fait. L'exposition prealable de ces catalyseurs aux rayons gamma du cobalt-60 a raison de 10{sup 11} erg/g a ete sans effet sur l'activite du catalyseur. Par contre, la meme exposition prealable des catalyseurs au Cr{sub 2}O{sub 3} - Al{sub 2}O{sub 3} aux rayons gamma du cobalt-60 a raison de 4,2 x 10{sup 11} erg/g a augmente l'activite catalytique d'environ 34% a 485{sup o}C, mais l'incorporation d'une quantite de {sup 147}Pm atteignant 148 mc/g de catalyseur est restee pratiquement sans effet. On n'a pas observe dans ce cas d'effet significatif des rayonnements sur la surface active ou sur l'energie d'activation apparente. (author) [Spanish] Los autores estudian la deshidratacion del ciclohexanol en fase vapor en presencia de catalizadores de sulfato magnesico y d e sulfato magnesico-sulfato sodico, asi como la transformacion del metilciclohexano en tolueno por deshidrogenacion sobre catalizadores de

  15. Disposal regulations and techniques applicable to devices using ionising radiation

    Vidal, J.P.

    1998-01-01

    L'office de Protection contre les rayonnement ionisants, being a government body under the supervision of Ministry of Health and Labour, among other different missions controls the compliance of radiation protection laws with the aim to guarantee the safe operation of equipment using ionising radiation sources. These regulations concerning competence of personnel, especially in the field of medicine or application of ionising radiation on humans, are restricted only to medical doctors (or dentists in their domain) by technical constraints dealing with design of equipment and its exploitation. At the same time regulations define conditions of permanent control in order to verify compliance of radiation protection laws

  16. Document sheet no.3. The sanitary effects and the medical uses of the radioactivity, the radiations, the biological effects, the medical uses; Fiche documentaire no.3. Les effets sanitaires et les usages medicaux de la radioactivite, rayonnements ionisants, les effets biologiques, les usages medicaux

    NONE

    2004-07-01

    In order to inform the public the ANCLI published information sheets. This sheet no.3 deals with the sanitary effects and the medical uses of the radioactivity. It presents the radiations definitions (the internal and external irradiation, the doses levels, the absorbed doses), the biological effects (deterministic effects, random effects and chronicity effects), and the medical uses (radiotherapy and monitoring of chemotherapy). (A.L.B.)

  17. The non ionizing radiations; Les rayonnements non ionisants

    Vecchia, P. [Institut National de la Sante, Lab. de Physique, Rome (Italy); Souques, M. [Electricite de France (EDF), Service des Etudes Medicales, 75 - Paris (France); Lambrozo, J. [EDF/GDF, Service des Etudes Medicales, 75 - Paris (France)] [and others

    2003-07-01

    The biological effects of non ionizing radiations are studied in this part. The magnetic fields and the cardiac implants, melatonin secretion among the electricians exposed to magnetic fields of 50 hz, the effects of electromagnetic fields in professional medium, evaluation of the effect of an exposure to a signal of a mobile phone (GSM 900) on the skin are the different subjects discussed. (N.C.)

  18. The Use of Ionizing Radiation as a Means of Processing Foodstuffs for Storage: Present Status and Future Prospects; Utilisation des Rayonnements Ionisants pour la Conservation de Produits Alimentaires: Situation Actuelle et Perspectives; Sostoyanie i perspektivy primeneniya ioniziruyushchikh izluchenij dlya obrabotki pishchevykh produktov v svyazi s ikh khraneniem; Estado Actual y Perspectivas del Empleo de las Radiaciones Ionizantes para la Conservacion de los Productos Alimenticios

    Rogachev, V. I. [Vsesojuznyj Nauchno-Issledovatel' skij Institut Konservnoj i Ovoshesushil' noj Promyshlennosti Moskva, SSSR (Russian Federation)

    1966-11-15

    The use of ionizing radiation for processing foodstuffs is being studied in the USSR, particularly in connection with the following: (a) prevention of sprouting in potatoes and onions; (b) disinfestation of foodstuffs; (c) suppression of microbe activity; either sterilization or partial inhibition of microflora activity to prolong the shelf life of various foodstuffs; and (d) alterations in the ripening time of fruits and vegetables after picking and/or harvesting. The paper reports the status of work performed in the USSR during recent years on each of these general topics and the prospects for the practical application of irradiation to a number of products are considered. Among the products in question are meat and meat products (raw and cooked semi-finished products, sausage products), domestic poultry, various fruits and vegetables, potatoes, grain, dehydrated products (dried fruits and vegetables, dried food concentrates). Practical methods of irradiating potatoes and onions to prevent sprouting during storage have already been developed, and very soon it will be possible to use radiation for the disinfestation of foodstuffs on an industrial scale. (author) [French] Les etudes sur l'utilisation des rayonnements ionisants pour la conservation des produits alimentaires se poursuivent en URSS.dans les domaines suivants: a) prevention de la germination des pommes de terre et des oignons; b) desinsection des produits alimentaires; c) elimination de l'activite biologique des micro-organismes en vue de la sterilisation ou de l'elimination partielle de l'activite biologique de la microflore en vue de prolonger les delais de conservation de divers produits alimentaires; et d) modifications des delais de maturite apres recolte des fruits et legumes. Pour chacun de ces domaines, l'auteur indique l'etat des travaux effectues en URSS pendant ces dernieres annees et examine les perspectives d'utilisation des rayonnements pour un certain nombre de produits. Au nombre de ces

  19. Appraisal of alternative skin model for the study of epidermal restoration following exposure to various environmental stress agents: ionising radiation and UV B; Evaluation d'un modele alternatif de peau dans l'etude de l'atteinte epidermique apres exposition a differents agents de stress environnementaux: rayonnements ionisants (RI) et ultra-violets B (UVB)

    Isoir, M

    2006-06-15

    Human skin is a major target tissue for ionising radiation (IR) and UV B. We developed a skin explant model and used 2 types of keratinocytes to study survival and oxidative stress induced by these radiations. We examined oxidative damages by measuring R.O.S. produced and cellular anti-oxidant defenses induced. We observed into skin exposed to IR a modulation of genes expression implied in the control of oxidative stress, confirmed by the decrease of catalase, glutathione peroxidase and superoxide dismutase enzymatic activities. The imbalance observed between anti- and pro-apoptotic genes expression shows that keratinocytes apoptosis may be partly dependent on radio-induced R.O.S. production. We showed the difference of radiosensitivity between N.H.E.K. and Ha Ca.T., which may be linked to their differential oxidative responses. In addition, during re-epithelialising, we demonstrated that activated N.H.E.K. after IR express keratin 6, release pro-inflammatory cytokines and proliferate, without modification of their differentiation. Treatment of N.H.E.K. with geranyl geranylacetone (G.G.A.) has a beneficial effect on their radio-induced activation by increasing IL-1 release, their migration in scrapped area and their survival. G.G.A. has an anti apoptotic ability (induction of Hsp70- caspase-3 pathway) and migratory properties (P38/RhoA activation) on N.H.E.K., but after IR, only caspase-3 pathway is induced. This work thus contributes to the understanding of cutaneous damages after IR and G.G.A. mechanism of action which accelerates re-epithelialising. (author)

  20. Appraisal of alternative skin model for the study of epidermal restoration following exposure to various environmental stress agents: ionising radiation and UV B; Evaluation d'un modele alternatif de peau dans l'etude de l'atteinte epidermique apres exposition a differents agents de stress environnementaux: rayonnements ionisants (RI) et ultra-violets B (UVB)

    Isoir, M

    2006-06-15

    Human skin is a major target tissue for ionising radiation (IR) and UV B. We developed a skin explant model and used 2 types of keratinocytes to study survival and oxidative stress induced by these radiations. We examined oxidative damages by measuring R.O.S. produced and cellular anti-oxidant defenses induced. We observed into skin exposed to IR a modulation of genes expression implied in the control of oxidative stress, confirmed by the decrease of catalase, glutathione peroxidase and superoxide dismutase enzymatic activities. The imbalance observed between anti- and pro-apoptotic genes expression shows that keratinocytes apoptosis may be partly dependent on radio-induced R.O.S. production. We showed the difference of radiosensitivity between N.H.E.K. and Ha Ca.T., which may be linked to their differential oxidative responses. In addition, during re-epithelialising, we demonstrated that activated N.H.E.K. after IR express keratin 6, release pro-inflammatory cytokines and proliferate, without modification of their differentiation. Treatment of N.H.E.K. with geranyl geranylacetone (G.G.A.) has a beneficial effect on their radio-induced activation by increasing IL-1 release, their migration in scrapped area and their survival. G.G.A. has an anti apoptotic ability (induction of Hsp70- caspase-3 pathway) and migratory properties (P38/RhoA activation) on N.H.E.K., but after IR, only caspase-3 pathway is induced. This work thus contributes to the understanding of cutaneous damages after IR and G.G.A. mechanism of action which accelerates re-epithelialising. (author)

  1. Ionising radiation

    Anon.

    1982-01-01

    The law covering ionising radiation in Luxembourg is summarised under the headings: introduction (the outline law of 25 March 1963, and the Grand-Ducal Decree of 8 February 1967); the control of establishments (the authorisation procedure; emergency measures, suspension and withdrawal of the authorisation; alterations to the establishment); the importation, distribution and transit of radioactive substances; the transport of radioactive substances; the protection and safety of the population as a whole; sanctions; international conventions. (U.K.)

  2. Measurement of the total ionisation intensity near the ground and separation of the various components; Mesure de l'intensite totale d'ionisation au voisinage du sol et separation de ses differentes composantes

    Grevet, Ph [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1965-06-01

    The aim of this work is to measure the total amount of ion-pairs produced in the air per unit time and unit volume. It is possible, furthermore, by using continuous recording to study the variations in the ionisation due to {alpha}, {beta} and {gamma} radiation at a height of one metre. The apparatus which has been developed consists of two chambers of 120 litres: one, hermetically sealed detects the {gamma} component, the other with a circulation of the ambient air detects the {alpha} and {gamma}; it is thus possible by difference to evaluate the {alpha} component. The chambers and the associated electronic equipment have been designed for continuous operation in the open air. Another chamber without walls can be used for measuring directly the total ionisation intensity and from this an approximate calculation may be made of the {beta} component. A series of recordings has been made near Saclay where the natural radio-activity level is moderate, and in regions of low and high activity (near the sea and in the CEA's mining divisions). It has thus been possible to show the variation in the {gamma} component as a function of the geographic position of the measurement (from 3.7 to 6.3 l/cm{sup 3}.s), the very large variations of the {alpha} component at a given place with changing meteorological conditions (from 1.5 to 45 l/cm{sup 3}.s at Saclay for example) an the far smaller variations in the {beta} component. (author) [French] Le but de ce travail est de mesurer la quantite totale de paires d'ions produite dans l'air par unite de temps et de volume. Des enregistrements continus permettent, de plus, d'etudier les variations a 1 m du sol de cette ionisation due aux rayonnements {alpha}, {beta} et {gamma}. L'appareillage mis au point est forme de deux chambres de 120 litres: l'une hermetiquement fermee detecte la composante {gamma}; l'autre avec circulation de l'air ambiant detecte {alpha} + {gamma} ce qui permet d'evaluer par difference la composante {alpha}. Les

  3. Atmospheric ionisation in Snowdonia

    Aplin, K L [Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH UK (United Kingdom); Williams, J H, E-mail: k.aplin1@physics.ox.ac.uk [Envirodata-Eyri, Bryn Goleu, Penmaen Park, Llanfairfechan, Gwynedd LL33 0RL (United Kingdom)

    2011-06-23

    Atmospheric ionisation from natural radioactivity and cosmic rays has been measured at several sites in Snowdonia from 2005-present. The motivation for this project was a combination of public engagement with science, and research into the effects of ionisation on climate. A four-component atmospheric radiometer instrument is co-located with the ionisation detectors and the data is remotely logged and displayed on the Web. Atmospheric ionisation from natural radioactivity varies with local geology, and the cosmic ray ionisation component is modulated by solar activity and altitude. Variations due to all these effects have been identified and are described.

  4. Effets des rayonnements de haute energie sur le cristallin de la souris

    Di Paola, M; Bianchi, M; Bianchi, M no 1; Baarli, J no 1; Di Paola, M no 1

    1973-01-01

    L'opacification du cristallin après irradiation par des neutrons et d'autres rayonnements ionisants a été largement étudiée, vu l'importance de telles recherches en radioprotection et la possibilité offerte par ce système d'analyser les effets produits par de petites doses de rayonnement. Les neutrons de haute énergie sont d'un intéret particulier pour la radioprotection près des accélérateurs et dans l'espace, mais jusqu'à présent les études ont été limitées aux neutrons d'énergie inférieur à 14 MeV. L'opacification du cristallin chez la souris, après irradiation par des neutrons de 400 MeV produits par le Synchro-Cyclotron du CERN, a été étudiée. Le valeurs d'E.B.R. ont été déterminées par comparaison avec des rayons X de 250 kV. Une breve discussion des résultats obtenus est inclue dans la présentation.

  5. Physical Properties of P.V.C. Attenuated Network Copolymers Produced by Ionizing Radiation; Proprietes physiques des copolymeres obtenus sous l'action de rayonnements ionisants et dont le reseau est attenue par l'effet du chlorure de polyvinyle; Fizicheskie svojstva polivinilkhloridnykh obednennykh tsepej sopolimerov, poluchennykh v rezul'tate vozdejstviya ioniziruyushchej radiatsii; Propiedades fisicas de los copolimeros de redes atenuadas por cloruro de polivinilo obtenidos por irradiacion

    Pinner, S H [Tube Investments Research Laboratories, Hinxton Hall, Cambridge (United Kingdom)

    1960-07-15

    The cross-linking of polyvinyl chloride with ionizing radiation poses special problems. Due to rather unfavourable cross-linking and dislinking parameters for this polymer, the radiation doses necessary for high cross-link densities are uneconomicall y large and discolouration and dehydrohalogenatio n are simultaneously produced. These difficulties have been overcome by the incorporation into the P. V. C., prior to irradiation, of diallyl and triallyl esters. Heavily cross-linked products are thereby obtained with relatively low doses of ionizing radiation. Examination of the physical properties of the products suggests that these are not simply graft copolymers, which term normally implies the presence of long branch chains, but are polymer attenuated allyl networks. In these materials, the desirable properties of the parent polymer and of the allyl network are combined. The tensile strength, modulus and elongation of the attenuated network copolymers are presented and discussed as a function of temperature and of the concentration and functionality of the allyl ester. Reference is also made to the swelling and chemical resistance of the products. (author) [French] La reticulation du chlorure de polyvinyle sous l'action des rayonnements ionisants pose des problemes particuliers. Les parametres de reticulation et de degradation etant plutot defavorables pour ce polymere, les doses d'irradiation necessaires a l'obtention de fortes densites de pontage sont trop elevees pour donner des resultats economiquement interessants; elles provoquent simultanement la decoloration et la deshalogenhydratation. Il a ete possible de surmonter ces difficultes par introduction d'esters diallyliques et triallyliques dans le chlorure de polyvinyle, avant irradiation. Ce procede permet d'obtenir au moyen de doses d'irradiation relativement faibles des produits fortement reticules. L'etude des proprietes physiques de ces produits montre qu'il s'agit non pas de simples copolymeres greffes

  6. After-Ripening of Red Pepper (Capsicum Annuum) as Affected by Ionizing Radiation; Effets des Rayonnements Ionisants sur le Murissement du Piment (Capsicum Annuum) Apres la Recolte; Vliyanie ioniziruyushchego izlucheniya na dozrevanie krasnogo pertsa (Capsicum Annuum); Efecto de las Radiaciones Ionizantes en la Postmaturacion del Pimiento Rojo (Capsicum Annuum)

    Farkas, J.; Kiss, I.; Andrassy, Eva [Central Food Research Institute, Budapest (Hungary)

    1966-11-15

    'effet direct des rayons X a des doses comprises entre 0 et 800 krad sur le piment doux fraichement cueilli et a des doses comprises entre 0 et 100 krad sur le murissement du piment apres la recolte. Sous l'effet de l'exposition a une dose comprise entre 400 et 800 krad, les pericarpes se-sont amollis; toutefois, la teneur en carotenoides n'a pas ete sensiblement reduite, meme apres exposition a une dose de 800 krad. Au cours de la periode de neuf semaines consecutives a l'irradiation, pendant laquelle les piments ont ete emmagasines a la temperature ambiante, on a constate que la teneur totale en pigments, sous forme de capsanthine avait augmente d'environ 90% dans les echantillons non traites. La formation des pigments a base de carotenoides a ete acceleree dans une certaine mesure par l'exposition a une dose de 80 rad et sensiblement acceleree par l'exposition a une dose de 2 krad. Les echantillons soumis a une dose de 2 krad avaient au bout de trois semaines la meme teneur en pigments que les echantillons temoins au bout de huit semaines. Toutefois, la teneur en pigments des echantillons irradies a diminue apres une periode d'emmagasinage de quatre a cinq semaines. L'exposition a des doses superieures a 10 krad a ralenti ou inhibe la formation des carotenoides pendant la periode d'emmagasinage (apres maturation). La reduction de la teneur en sucres et la vitesse de dessiccation n'ont pas ete affectees par l'exposition a des doses de 0 a 100 krad. Etant donne les effets nefastes de l'exposition aux doses de rayonnements de plusieurs centaines de krad necessaires pour detruire les moisissures qui provoquent l'alteration du piment a forte teneur en eau, ou pour inhiber fortement le developpement de ces organismes, il ne semble pas souhaitable d'utiliser les rayonnements pour reduire les pertes de piments fraichement cueillis. Neanmoins, l'application des doses tres faibles qui stimulent la formation des carotenoides semble devoir donner de bons resultats, car elle abrege la

  7. Radioprotection rayonnements, dosimétrie, protection

    Marey, Gérard

    2014-01-01

    Pour tous les travailleurs du nucléaire comme pour les étudiants des licences professionnelles et des BTS Environnement nucléaire et BTS radioprotection, l'ouvrage rassemble de façon progressive, claire et précise toutes les informations scientifiques et pratiques qui leur sont indispensables. Une première partie résume les données de base relatives à la structure de la matière, la stabilité des noyaux, les différents rayonnements, leur énergie et la décroissance radioactive. La deuxième partie constitue une approche progressive de la radioprotection s'appuyant sur l'influence des rayonnement sur la matière pour définir les notions de dose et aborder le dimensionnement des protections biologiques et des éléments de ventilation. Enfin, la dernière partie traite de la mise en oeuvre pratique de la radioprotection sur le terrain et de la gestion des déchets nucléaires en application de la technologie actuelle, de la réglementation et des directives imposées par l'exploitant qu'est EDF. De...

  8. 20 years of interlaboratory tests in the service of radioactivity measurement quality. 20 ans de tests interlaboratoires au service de la qualite des mesures de radioactivite

    Cance, M. (CEA Centre d' Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. des Applications et de la Metrologie des Rayonnements Ionisants)

    1992-01-01

    In the framework of French national metrological coordination, the Laboratoire de Metrologie des Rayonnements Ionisants (LMRI) organizes since 20 years, each year an interlaboratory test program. The tests concern radioactivity, radio analysis and neutron and gamma dosimetry. In this paper, a review of interlaboratory tests proposed by LMRI is proposed from 1971 to 1991. For the last twenty years, 97 tests have been realized, half in activity measurement, third in radio analysis and 20% in dosimetry. About forty radionuclides (from Tritium to Americium 241) are concerned by these tests with an activity range from 1 Becquerel to 100 megabecquerels. The 120 laboratories having participated at these tests belong essentially to CEA group, EDF or medical sector.

  9. About particular use of ionizing radiations; Des usages particuliers des rayonnements ionisants

    NONE

    2001-02-01

    Different uses of ionizing radiations are reviewed: tracers techniques, nuclear gauges, dating by carbon 14, silica doping, use of gamma irradiation for the density measurement in civil engineering, use of a electron capture detector to study by gas chromatography chlorinated contaminants in environment, neutron activation as environmental gauge, analysis of lead in paint and pollutants in ground and dusts, help for work of art valuation by x spectrometry. (N.C.)

  10. Effects of low doses of ionizing radiation; Effets des faibles doses de rayonnements ionisants

    Masse, R. [Office de Protection contre les Rayonnements Ionisants, 78 - le Vesinet (France)

    2006-07-01

    Several groups of human have been irradiated by accidental or medical exposure, if no gene defect has been associated to these exposures, some radioinduced cancers interesting several organs are observed among persons exposed over 100 to 200 mSv delivered at high dose rate. Numerous steps are now identified between the initial energy deposit in tissue and the aberrations of cell that lead to tumors but the sequence of events and the specific character of some of them are the subject of controversy. The stake of this controversy is the risk assessment. From the hypothesis called linear relationship without threshold is developed an approach that leads to predict cancers at any tiny dose without real scientific foundation. The nature and the intensity of biological effects depend on the quantity of energy absorbed in tissue and the modality of its distribution in space and time. The probability to reach a target (a gene) associated to the cancerating of tissue is directly proportional to the dose without any other threshold than the quantity of energy necessary to the effect, its probability of effect can be a more complex function and depends on the quality of the damage produced as well as the ability of the cell to repair the damage. These two parameters are influenced by the concentration of initial injuries in the target so by the quality of radiation and by the dose rate. The mechanisms of defence explain the low efficiency of radiation as carcinogen and then the linearity of effects in the area of low doses is certainly the least defensible scientific hypothesis for the prediction of the risks. (N.C.)

  11. Technical and Economic Considerations in the Preservation of Meats and Poultry by Ionizing Radiation; Considerations d'Ordre Technique et Economique sur la Conservation des Viandes et de la Volaille par les Rayonnements Ionisants; Tekhnicheskie i ehkonomicheskie soobrazheniya otnositel'no'konservatsii myasa i ptitsy s pomoshch'yu ioniziruyushchikh izluchenij; Consideraciones Tecnicas y Economicas Acerca de la Conservacion de Carnes y Volateria por Irradiacion

    Urbain, W. M. [Department of Food Science, Michigan State University, East Lansing, MI (United States)

    1966-11-15

    Radiation-sterilized meats and poultry can be of a quality better than that obtained with thermal processing. Where the normal method of preservation of meat and poultry during distribution is refrigeration, radiation at sterilizing levels is not likely to replace it. A principal reason for this is cost. In such a civilian market, radiation-sterilized meats will serve primarily as convenience foods. Radiation-pasteurization could provide a significant product life extension for fresh meats and poultry by delaying microbial spoilage, especially in the centralized preparation of retail cuts. Other factors of meat spoilage of a chemical or physical nature, however, are not controlled by radiation; and until they are, there is no real marketing value in the use of radiation. For fresh or frozen poultry there is the possibility of Salmonella control, should this be needed. Costs for sterilization and pasteurization are estimated and are presented in a form to permit selection of specific conditions within a range for certain important variables. From a commercial viewpoint, it is important to determine the consumer acceptance of radiation- sterilized meats and poultry. The usual approach to such a determination is to market the products in question in a limited manner and to measure the acceptance under such market conditions. To accomplish this with radiation-sterilized foods, the next step appears to be to obtain a production capability to supply the products for test marketing. (author) [French] Les viandes et la volaille sterilisees par les rayonnements peuvent etre de meilleure qualite que celle obtenue par un traitement thermique; Lorsqu'on utilise la refrigeration comme methode normale de conservation de la viande et de la volaille en cours de distribution, il est peu probable qu'on lui substitue l'irradiation a des doses sterilisantes. La principale raison eri est le cout eleve de l'irradiation. Dans un marche destine a repondre aux besoins civils, les viandes

  12. Generator for ionising radiation

    Romanovsky, V.F.; Panasjuk, V.S.; Stepanov, B.M.; Ovcharov, A.M.; Akimov, J.A.

    1979-01-01

    The generator for ionising radiation wherein a transmitter for ionising radiation contains a resonance transformer wherein the field coil is composed of a low voltage outside portion and a transformer coil, electrically connected with an electrically conducting housing of the resonance transformer, and an acclerating tube wherein the high voltage electrode is coupled with the high voltage end of the transformer coil of the resonance transformer and fixed to one of the ends of the tubular insulator of the accelerator tube, wherein the low voltage electrode is electrically connected with the housing of the resonance transformer and a source of charged particles is introduced into the evacuated inner space of the acceleration tube and electrically connected with one of the electrodes thereof, is described. (G.C.)

  13. Ionising radiation. Part 2

    2000-01-01

    A brief tutorial on the health effects of ionising radiation is presented. The distinction between somatic and genetic health effects is explained. The two types of somatic health effects, i.e., acute and chronic effects, are discussed, as well as the concepts of ''deterministic'' and ''stochastic'' (also called ''probabilistic'') health effects. The possibility of cancer caused by DNA damage is discussed. The document ends with the definition of some key radiation terms

  14. Genetic effects of ionising radiation

    Saunders, P.

    1981-01-01

    The mutagenic effects of ionising radiation on germ cells with resulting genetic abnormalities in subsequent generations, are considered. Having examined a simple model to explain the interaction of ionising radiation with genetic material and discussed its limitations, the methods whereby mutations are transmitted are discussed. Methods of estimating genetic risks and the results of such studies are examined. (U.K.)

  15. Contribution à l'étude de la radioactivité gamma du sable des ...

    Les familles de l'Uranium -238, de l'Uranium -235, du Thorium -232 et du Potassium -40 sont d'origines telluriques et contribuent de manière générale aux expositions internes et externes d'un individu. Ce travail a pour objectif de mesurer la radioactivité du sable de deux plages de la baie de Diego-Suarez, à savoir celles ...

  16. Study of {gamma} radiation from uranium rods during deactivation; Etude du rayonnement {gamma} des barres d'uranium en court de desactivation

    Balestic, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1957-07-01

    The classical formulae giving the {gamma} activities of the fission products contained in a uranium rod after unloading from the pile are reviewed without being proved. The knowledge of these activities makes it possible, by means of the method proposed here, to determine the intensities of ionisation at a point outside the rod, and thus to establish {gamma} radiation diagrams. The different parameters introduced in the calculation are geometric (dimensions of the bars and coordinates of the point considered), energetic (power at which the bar has been irradiated) and temporal (duration of the irradiation and deactivation). A numerical example follows the demonstration of the general formulae, {gamma} flux measurements carried out in the deactivation well of P2 (Saclay pile) define the accuracy of the method. In conclusion, it is suggested that radiation diagrams be used in (planning the use of) industrial irradiators for radiochemical polymerisation or the preservation of food products. (author) [French] On rappelle sans demonstration les formules classiques donnant les activites {gamma} des produits de fission contenus dans une barre d'uranium apres defournement. La connaissance de ces activites permet par la methode proposee de passer aux intensites d'ionisation en un point exterieur a la barre et d'etablir ainsi des diagrammes de rayonnement {gamma}. Les differents parametres introduits dans le calcul sont d'ordre geometrique (dimensions des barres et coordonnees du point considere), d'ordre energetique (puissance a laquelle la barre a ete irradiee) et fonction du temps (duree d'irradiation et de desactivation). Un exemple numerique fait suite a la demonstration des formules generales. Des mesures de flux {gamma} effectuees au puits de desactivation de P2 (pile de Saclay) fixent le degre d'approximation de la methode. En conclusion, on suggere l'utilisation des diagrammes de rayonnement dans l'etablissement de projets d'irradiateurs industriels pour les

  17. Use of ionising radiation

    1988-11-01

    The Committee has inquired into and reported on the use of ionising radiation for commercial sterilisation, disinfestation, food preservation and other purposes with particular reference to human health and safety; environmental impacts, and adequacy of assessment and regulatory procedures. While food irradiation is apparently commercially successful overseas the application to Australia seems extremely limited - it would be used primarily for disinfestation of insect pests and perhaps to reduce levels of harmful bacteria in a limited range of foods. For other applications there are effective and more economic alternatives. The report reviews other studies of food irradiation and the policies and practices governing its use in other countries. The safety of irradiated food, the radiological safety issues and the regulations which would be required in Australia are dealt with in detail. The Committee recommends, inter alia, that the Australian Government should not approve the irradiation of food in Australia until such time as a routine commercial method of detection has been developed and that the import of caesium 137 for use as an irradiation source in commercial irradiation facilities be prohibited

  18. Polarization of Bremsstrahlung; Polarisation du rayonnement de freinage

    Miller, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1957-07-01

    The numerical results for the polarization of Bremsstrahlung are presented. The multiple scattering of electrons in the target is taken into account. The angular-and photon energy dependences are seen on the curves for an incident 25 MeV electron energy. (Author) [French] Le taux de polarisation d'un spectre de rayonnement de freinage est calcule pour une cible d'epaisseur finie en tenant compte de la diffusion multiple des electrons dans la cible. Les courbes sont tracees pour les electrons incidents d'energie 25 MeV, pour differentes energies de photons, et a differents angles. (auteur)

  19. Food ionisation. Realities and perspectives

    Bonnet, G.

    1994-06-01

    The ionisation of food is a treatment using a certain type of energy. the radiations used in the industrial treatments are limited to three sources. The gamma radiations, the x radiations and the electrons beams emitted with accelerators. The physical treatments by ionizing radiations have for aim to cleanse and to increase the conservation time of food. Now, the applications in agriculture and food industry, are still marginal. The industrial using ionisation are these ones that did not find any alternative decontamination method. The barriers are more scientific or technical or economical than a question of regulation or behaviour. (N.C.)

  20. Dose limits for ionising radiation

    Gifford, D.

    1989-01-01

    Dose limits for exposure to ionising radiation are assessed to see if they give sufficient protection both for the occupationally exposed and for the general public. It is concluded that current limits give a level of safety that satisfies the necessary criteria in the light of present knowledge and further reductions would be unlikely to improve standards of safety. (author)

  1. Working safely with ionising radiation

    McDowell, D.J.

    1990-01-01

    A small leaflet provides information on working safely with ionizing radiation. Topics covered include the types of radiation, radiological units, external radiation, contamination and internal radiation, methods of protection form radiation, radiation monitors, protective clothing for contamination, personal dosemeters, radiation dose limits for classified workers and finally the Ionising Radiations Regulations 1985. (UK)

  2. 2008 activity report of the French metrology - Ionising radiation; Rapport d'activite 2008 de la metrologie francaise - Rayonnements ionisants

    Anon

    2009-07-01

    The activities of this section are entrusted to the Henry Becquerel national laboratory (LNE-LNHB), the national laboratory of metrology of the CEA-Saclay, and to the laboratory of dose metrology (LMDN) under the management of IRSN-Cadarache. They treat of ionizing radiations metrology in the domains of activity, photons and charged particles dosimetry, and basic data. This article summarizes the 2008 works carried out at both laboratories: international actions and comparisons, instrumentation improvements, establishment of national references. (J.S.)

  3. Health and biological effects of non-ionizing radiations; Effets biologiques et sanitaires des rayonnements non ionisants

    De Seze, R.; Souques, M.; Aurengo, A.; Bach, V.; Burais, N.; Cesarini, J.P.; Cherin, A.; Decobert, V.; Dubois, G.; Hours, M.; Lagroye, I.; Leveque, Ph.; Libert, J.P.; Lombard, J.; Loos, N.; Mir, L.; Perrin, A.; Poulletier De Gannes, F.; Thuroczy, G.; Wiart, J.; Lehericy, St.; Pelletier, A.; Marc-Vergnes, J.P.; Douki, Th.; Guibal, F.; Tordjman, I.; Gaillot de Saintignon, J.; Collard, J.F.; Scoretti, R.; Magne, I.; Veyret, B.; Katrib, J.

    2011-07-01

    This document gathers the slides of the available presentations given during this conference day on the biological and health effects of non-ionizing radiations. Sixteen presentations out of 17 are assembled in the document and deal with: 1 - NMR: biological effects and implications of Directive 2004/40 on electromagnetic fields (S. Lehericy); 2 - impact of RF frequencies from mobile telephone antennas on body homeostasis (A. Pelletier); 3 - expression of stress markers in the brain and blood of rats exposed in-utero to a Wi-Fi signal (I. Lagroye); 4 - people exposure to electromagnetic waves: the challenge of variability and the contribution of statistics to dosimetry (J. Wiart); 5 - status of knowledge about electromagnetic fields hyper-sensitivity (J.P. Marc-Vergnes; 6 - geno-toxicity of UV radiation: respective impact of UVB and UVA (T. Douki); 7 - National day of prevention and screening for skin cancers (F. Guibal); 8 - UV tan devices: status of knowledge about cancer risks (I. Tordjman, and J. Gaillot de Saintignon); 9 - modulation of brain activity during a tapping task after exposure to a 3000 {mu}T magnetic field at 60 Hz (M. Souques and A. Legros); 10 - calculation of ELF electromagnetic fields in the human body by the finite elements method (R. Scoretti); 11 - French population exposure to the 50 Hz magnetic field (I. Magne); 12 - LF and static fields, new ICNIRP recommendations: what has changed, what remains (B. Veyret); 13 - risk assessment of low energy lighting systems - DELs and CFLs (J.P. Cesarini); 14 - biological effects to the rat of a chronic exposure to high power microwaves (R. De Seze); 15 - theoretical and experimental electromagnetic compatibility approaches of active medical implants in the 10-50 Hz frequency range: the case of implantable cardiac defibrillators (J. Katrib); French physicians and electromagnetic fields (M. Souques). (J.S.)

  4. The place of ionizing radiation in the cancer genesis; La place des rayonnements ionisants dans la genese des cancers

    Simon, J. [Societe Francaise d' Energie Nucleaire, 75 - Paris (France)

    2009-12-15

    Two different fields are considered: the field of high radiation doses (over 1 Sv), the contribution of ionizing radiation in the carcinogenesis is doubtless and the linear dose-effect relationship is unshakable. but this high doses area is rare ( major accident of civil nuclear, radiotherapy, war with use of nuclear weapon) and escapes to usual standards. The field of low dose irradiation (inferior to 100 MSv) we cannot assure the absence of carcinogen risk of ionizing radiation. We can tell that this risk is very low, very inferior to 5% by sievert accepted by the ICRP in conformance with the precautionary principle. In any case, very inferior to the risk in relation with the big causes of cancer that are addiction to smoking, (30% of cancers), food (30% of cancers), chronic diseases (11% of cancers) and hormonal processes (10% of cancers). (N.C.)

  5. Biological effects of the ionizing radiation. Press breakfast; Effets biologiques des rayonnements ionisants. Petit dejeuner de presse

    Flury-Herard, A [CEA, Direction des Sciences du Vivant, DSV, 75 - Paris (France); Boiteux, S; Dutrillaux, B [CEA/Fontenay-aux-Roses, Direction des Sciences du Vivant, DSV, 92 (France); Toledano, M [CEA Saclay, Direction des Sciences du Vivant, DSV, 91 - Gif-sur-Yvette (France)

    2000-06-01

    This document brings together the subjects discussed during the Press breakfast of 29 june 2000 on the biological effects of the ionizing radiations, with scientists of the CEA and the CNRS. It presents the research programs and provides inquiries on the NDA operating to introduce the NDA damages by ionizing radiations, the possible repairs and the repair efficiency facing the carcinogenesis. Those researches allow the scientists to define laws on radiation protection. (A.L.B.)

  6. Advisory group on ionising radiation

    Harrison, J.R.

    1996-01-01

    The Advisory Group on Ionising Radiation has a busy and challenging work programme. Its reports will be published in the Documents of the NRPB series. These may advise further research or could form the basis of formal NRPB advice. Covering the full spectrum of radiation issues at work, in public health and clinical medicine, and the environment, it should enhance the radiation advice available to NRPB. (author)

  7. European Code against Cancer 4th Edition: Ionising and non-ionising radiation and cancer

    N. McColl (Neil); A. Auvinen (Anssi); A. Kesminiene (Ausrele); C. Espina (Carolina); F. Erdmann (Friederike); E. de Vries (Esther); R. Greinert (Rüdiger); J. Harrison (John); J. Schüz (Joachim)

    2015-01-01

    textabstractIonising radiation can transfer sufficient energy to ionise molecules, and this can lead to chemical changes, including DNA damage in cells. Key evidence for the carcinogenicity of ionising radiation comes from: follow-up studies of the survivors of the atomic bombings in Japan; other

  8. 122 Contribution à l'étude de dose due à la radioactivité gamma du ...

    BRIANT

    Le but de ce travail est d'étudier la radioactivité gamma des sols sur la rive de la baie des français et de déterminer ..... Tableau 3: Activités moyennes dans le sol et débit de dose absorbée à l'air libre .... Sur le bord de la baie, nous constatons.

  9. The reactor Melusine - radiation measurements carried out at the start of operation and during the first ascents to power; Pile Melusine - mesures de rayonnement effectuees au demarrage et pendant les premieres montees en puissance

    Coutrot, V; Delpuech, J; Fitoussi, L [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    amoindries. Dans la premiere partie de ce rapport, sont presentes les resultats des mesures de rayonnements effectuees pendant des fonctionnements en palier des puissances faibles ne depassant pas 500 W; en particulier, mesures a niveaux d'eau variables dans l'eau de la piscine et dans l'axe des canaux ouverts. Dans la seconde partie, sont presentes les resultats concernant les mesures des rayonnements effectuees dans les differents locaux, l'etude de l'activation des bouchons des canaux experimentaux, des materiaux se trouvant dans le compartiment avant ainsi que l'etude de la radioactivite de l'eau de la piscine et de l'air de refroidissement des canaux. (auteur)

  10. Diseases induced by ionising radiation

    1984-11-01

    An interim report is presented by the Industrial Injuries Advisory Council in accordance with Section 141 of the Social Security Act 1975 on the question whether the terms of prescription for occupational diseases induced by ionising radiation should be amended to cover a wider range of conditions. A lack of persuasive statistical data has prevented reliable estimates of health risks of radiation workers in the UK to be made. However the report gives details of the progress made so far and the difficulties encountered. (U.K.)

  11. Beam Cooling with ionisation losses

    Rubbia, Carlo; Kadi, Y; Vlachoudis, V

    2006-01-01

    A novel type of particle "cooling", called Ionization Cooling, is applicable to slow (v of the order of 0.1c) ions stored in a small ring. The many traversals through a thin foil enhance the nuclear reaction probability, in a steady configuration in which ionisation losses are recovered at each turn by a RF-cavity. For a uniform target "foil" the longitudinal momentum spread diverges exponentially since faster (slower) particles ionise less (more) than the average. In order to "cool" also longitudinally, a chromaticity has to be introduced with a wedge shaped "foil". Multiple scattering and straggling are then "cooled" in all three dimensions, with a method similar to the one of synchrotron cooling, but valid for low energy ions. Particles then stably circulate in the beam indefinitely, until they undergo for instance nuclear processes in the thin target foil. This new method is under consideration for the nuclear production of a few MeV/A ion beams. Simple reactions, for instance Li 7 + D Li 8 + p, are more ...

  12. Food preservation by ionising radiation

    Andrade, M. E.

    1996-01-01

    The process of food preservation by ionising radiation is an alternative, or a complement, to the traditional methods of heating, refrigerating, freezing or using chemical additives. The study and development of this technique has started on the beginning of the fifties but it is based on the radiation killing effect on micro-organisms discovered by the end of last century. Foodstuffs are treated in appropriate plants: isotopic facilities (gamma radiation) and accelerated electron beams produced by machines called accelerators. The FAO and WHO in close cooperation with the IAEA have played an important role on the development of the process and on the increment of the industrial application of food irradiation. Over the world there are about 37 countries trading foods treated by ionising radiation. However, governments have been slow to clear the utilization of this process. The main reason of this attitude is in general due to the fact that the advantages of the technique are not clearly understood. Therefore, the dissemination of the information could on one hand clarify who has to take decisions and on the other hand support the choice of those foods by the consumers. This is the unique way to dynamize the application of this process

  13. Nucleation in an ultra low ionisation environment

    Enghoff, Martin Andreas Bødker

    in aerosol nucleation. By exposing a controlled volume of air to varying levels of ionising radiation, and with the minimum ionisation level vastly reduced compared to normal surface laboratory conditions, we have provided both a validation of earlier studies of ion-induced nucleation and extended...

  14. The radioactivity of the Hercynian Vosges; La radioactivite des Vosges hercyniennes

    Rothe, J.P. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Institut de Physique du Globe de Strasbourg, 67 (France)

    1957-07-01

    On november 22, 1950, in the course of the formal beginning of term ceremony, the University of Strasbourg was pleased to confer on Professor VENING-MEINESZ the degree of Doctor Honoris Causa. In his speech of acknowledgement, Professor VENING-MEINESZ paid tribute to the fact that his colleague, Edmond ROTHE, had created at Strasbourg a centre of radio-geological research and during his visit to the Institute of Terrestrial Physics, the scholar whom we are honouring today expressed an interest in the new measurements that I was able to show him. I am happy to offer to him in homage some results of a systematic study of radioactivity of the Hercynian Vosges. (author) [French] Le 22 novembre 1950, au cours de sa seance solennelle de rentree, l'Universite de Strasbourg avait la joie de decerner au professeur VENING-MEINESZ le grade de Docteur Honoris Causa. Dans son allocution de remerciements, le professeur VENING-MEINESZ voulait bien rappeler que son collegue Edmond ROTHE avait cree a Strasbourg un centre de recherches de radiogeologie; et vistant l'Institut de Physique du Globe, le savant que nous honorons aujourd'hui acceptait de s'interesser aux mesures nouvelles que je pus alors lui presenter. Je suis heureux de lui offrir en hommage quelques resultats d'une etude systematique de radioactivite des Vosges hercyniennes. (auteur)

  15. The radioactivity of the Hercynian Vosges; La radioactivite des Vosges hercyniennes

    Rothe, J P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Institut de Physique du Globe de Strasbourg, 67 (France)

    1957-07-01

    On november 22, 1950, in the course of the formal beginning of term ceremony, the University of Strasbourg was pleased to confer on Professor VENING-MEINESZ the degree of Doctor Honoris Causa. In his speech of acknowledgement, Professor VENING-MEINESZ paid tribute to the fact that his colleague, Edmond ROTHE, had created at Strasbourg a centre of radio-geological research and during his visit to the Institute of Terrestrial Physics, the scholar whom we are honouring today expressed an interest in the new measurements that I was able to show him. I am happy to offer to him in homage some results of a systematic study of radioactivity of the Hercynian Vosges. (author) [French] Le 22 novembre 1950, au cours de sa seance solennelle de rentree, l'Universite de Strasbourg avait la joie de decerner au professeur VENING-MEINESZ le grade de Docteur Honoris Causa. Dans son allocution de remerciements, le professeur VENING-MEINESZ voulait bien rappeler que son collegue Edmond ROTHE avait cree a Strasbourg un centre de recherches de radiogeologie; et vistant l'Institut de Physique du Globe, le savant que nous honorons aujourd'hui acceptait de s'interesser aux mesures nouvelles que je pus alors lui presenter. Je suis heureux de lui offrir en hommage quelques resultats d'une etude systematique de radioactivite des Vosges hercyniennes. (auteur)

  16. Health Service use of ionising radiations: Guidance

    1995-01-01

    This booklet gives outline guidance on the use of ionising radiations in the Health Service in the United Kingdom. Extensive reference is made to documents where more detailed information may be found. The guidance covers general advice on the medical use of ionising radiations, statutory requirements, and guidance on selected Health Service issues such as patient identification procedures, information management systems, deviations from prescribed radiation dose, imaging and radiotherapy. (57 references) (U.K.)

  17. Ionising radiation - physical and biological effects

    Holter, Oe.; Ingebretsen, F.; Parr, H.

    1979-01-01

    The physics of ionising radiation is briefly presented. The effects of ionising radiation on biological cells, cell repair and radiosensitivity are briefly treated, where after the effects on man and mammals are discussed and related to radiation doses. Dose limits are briefly discussed. The genetic effects are discussed separately. Radioecology is also briefly treated and a table of radionuclides deriving from reactors, and their radiation is given. (JIW)

  18. A Discussion about Ionising and Non-Ionising Radiation and the Critical Issue of Mobile Phones

    Kontomaris, Stylianos-Vasileios; Malamou, Anna

    2018-01-01

    Electromagnetic radiation is one of the most important issues affecting peoples' lives today. The misunderstanding of students and the general population of the effects of electromagnetic radiation is a problem which must be eliminated. Thus, a discussion about ionising and non-ionising radiation focusing on the crucial issue of radiation emitted…

  19. Agent principal de rayonnement et de mobilisation stratégiques (h/f ...

    Dans ce contexte, l'agent principal de rayonnement et de mobilisation stratégiques élabore des démarches qui permettent de mobiliser les chercheurs et les principaux utilisateurs de la recherche dans les régions visées, afin de faire en sorte qu'ils aient l'occasion de participer à la définition des besoins de recherche dans ...

  20. Impact assessment of ionising radiation in wildlife

    2001-01-01

    This R and D project was commissioned by the Environment Agency and English Nature in January 2001 to provide up-to-date information on ionising radiation impact to wildlife, upon which a robust assessment approach may be developed. The methodology will provide an interim approach, whilst awaiting the outcome of the European Commission funded project 'Framework for Assessment of Environmental Impact' (FASSET) due to end in October 2003. The aims of the report were: to summarise the latest research on the behaviour, transfer and impact of ionising radiation effects on wildlife; to outline and review relevant European Directives which have impacted on the requirements to assess the impact to wildlife from ionising radiation in the UK; to consider the role of regulatory bodies in assessing the impact of ionising radiation on wildlife with respect to England and Wales; to make recommendations on the relative biological effectiveness of different types of radiation with respect to wildlife; and to recommend an approach with which to assess the 'scale of risk' to wildlife from the effects of ionising radiation, with spreadsheets to support the methodology. The report describes the behaviour and transfer of radionuclides in a number of different ecosystem types. Particular emphasis is placed on those ecosystems most likely to be impacted by the authorised discharges of radioactivity within the UK. As there is no international consensus on the approach to be taken to assess the impact of ionising radiation on wildlife, some countries have adopted their own legislation. The report evaluates these regulatory frameworks and describe the current UK position

  1. Impact assessment of ionising radiation on wildlife

    Copplestone, D.; Bielby, S.; Jones, S.

    2001-01-01

    This R and D project was commissioned by the Environment Agency and English Nature in January 2001 to provide up-to-date information on the impacts of ionising radiation on wildlife, upon which a robust assessment approach may be developed. This approach will also feed into the European Commission funded project 'Framework for Assessment of Environmental Impact' (FASSET), due to complete in October 2003. This report describes the behaviour and transport of radionuclides in the environment, considers the impact of ionising radiation on wildlife, and makes recommendations on an approach for the impact assessment of ionising radiation on wildlife for England and Wales. The assessment approach focuses on three ecosystems representative of those considered potentially most at risk from the impact of authorised radioactive discharges, namely a coastal grassland (terrestrial ecosystem); estuarine and freshwater ecosystems. The likely scale of the impact on wildlife is also assessed in light of a preliminary analysis based on this assessment approach. The aims of the report are: to summarise the latest research on the behaviour, transfer and impact of ionising radiation effects on wildlife; an outline and review of the relevant European and national legislation which has impacts on the requirements for assessments of the impact of ionising radiation on wildlife in the UK; to consider the role of regulatory bodies in assessing the impact of ionising radiation on wildlife with respect to England and Wales; to make recommendations on the relative biological effectiveness of different types of radiation with respect to wildlife; and to recommend an approach to assess the impacts to wildlife from ionising radiation from authorised discharges in England and Wales, with spreadsheets to support the methodology. The report demonstrates the behaviour and transfer of radionuclides in a number of different ecosystem types. Particular emphasis is placed on exposure pathways in those

  2. Détection de rayonnements et instrumentation nucléaire

    Lyoussi, Abdallah

    2010-01-01

    La détection de rayonnements nucléaires passe obligatoirement par leur interaction avec le milieu détecteur. Ces interactions génèrent directement ou indirectement des charges électriques lesquelles, une fois collectées sont (pré)amplifiées et converties en signaux électriques. Cette opération est rendue possible grâce à la polarisation électrique du détecteur conduisant à l'établissement d'un champ électrique responsable du mouvement des charges produites et de leur collection. D'une manière générale la détection et la mesure de rayonnements est un processus à plusieurs étapes comme le montre le synoptique de la figure 1.1. Il s'agit dans un premier temps de faire interagir le rayonnement incident utile avec le milieu détecteur après qu'il ait franchi l'espace «source-détecteur». Ces interactions sont ensuite converties en impulsions électriques qui sont traitées électroniquement et acheminées vers une unité d'acquisition et d'analyse. On obtient ainsi un premier résultat a...

  3. The radiation linked to uranium natural radioactivity enlightened by Abel Niepce long time before Henri Becquerel;Les rayonnements lies a la radioactivite naturelle de l'uranium mis en evidence par Abel Niepce bien avant Henri Becquerel

    Fournier, J.; Niepce, J.C.

    2009-09-15

    Abel Niepce was rarely mentioned during the celebration of the centenary of the radioactivity discovery.This discovery, supposed due to chance alone, is entirely attributed to Henri Becquerel. But Abel Niepce who made the first observation of radiation from uranium with the impression of a photographic plate, but without giving it meaning. This is a slow process which in forty years, from an observation misunderstood by Abel Niepce to its interpretation by Frederick Soddy, through the experiments of Henri Becquerel and thanks to developments in other knowledge (electron, X-rays) has led to a scientific progress known under the term of radioactivity, name given by Marie Slodowska-Curie. (N.C.)

  4. Instrument for continuous supervision of the radioactivity of CO{sub 2} coolant in piles - DCCA -CO{sub 2} (1960); Dispositif de controle continu de la radioactivite du CO{sub 2} de refroidissement des piles - DCCA - CO{sub 2} (1960)

    Fitoussi, L [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    This paper describes an apparatus for continuous measurement of CO{sub 2} activity, which can be used on piles cooled by circulation of gas. The first part is devoted mainly to describing the apparatus used and the character of the radioactivity and thermodynamic measurements carried out, and giving the general characteristics of the gas circuit required if the instrument is to be suitably gas-tight. In the second part theoretical calculations are given, particularly on the determination of the ionisation current in an ionisation chamber with circulating gas. Several parameters enter into this determination, such as the mean path of {beta} particles in the ionisation chamber, the linear number of ion pairs formed in the gas by these {beta} particles as a function of their energy, the temperature and pressure of the gas in the ionisation chamber. This part also evaluates the sensitivity areas of the apparatus for measuring the concentrations of radioactive gases such as argon-41 and fission gases from uranium-235 in the CO{sub 2} coolant. In the last part are described the results of measurements performed with such an apparatus on the pile EL2, the special investigations carried out on the CO{sub 2} coolant of this pile, and the information gained during normal operation and during accidents. The DCCA - CO{sub 2} which has just been put in operation at G2 is briefly presented. In the conclusion the possibilities offered by this apparatus are underlined. (author) [French] Ce rapport a pour but de presenter le Dispositif de Controle continu de l'Activite du CO{sub 2} pouvant etre utilise aupres des piles refroidies par une circulation de gaz. La premiere partie du rapport consiste essentiellement a decrire l'ensemble de l'appareillage mis en oeuvre, a preciser la nature des mesures de radioactivite et de thermodynamique effectuees et a citer les caracteristiques generales du circuit de gaz pour avoir un dispositif presentant une etancheite efficace. Dans la seconde

  5. Instrument for continuous supervision of the radioactivity of CO{sub 2} coolant in piles - DCCA -CO{sub 2} (1960); Dispositif de controle continu de la radioactivite du CO{sub 2} de refroidissement des piles - DCCA - CO{sub 2} (1960)

    Fitoussi, L. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    This paper describes an apparatus for continuous measurement of CO{sub 2} activity, which can be used on piles cooled by circulation of gas. The first part is devoted mainly to describing the apparatus used and the character of the radioactivity and thermodynamic measurements carried out, and giving the general characteristics of the gas circuit required if the instrument is to be suitably gas-tight. In the second part theoretical calculations are given, particularly on the determination of the ionisation current in an ionisation chamber with circulating gas. Several parameters enter into this determination, such as the mean path of {beta} particles in the ionisation chamber, the linear number of ion pairs formed in the gas by these {beta} particles as a function of their energy, the temperature and pressure of the gas in the ionisation chamber. This part also evaluates the sensitivity areas of the apparatus for measuring the concentrations of radioactive gases such as argon-41 and fission gases from uranium-235 in the CO{sub 2} coolant. In the last part are described the results of measurements performed with such an apparatus on the pile EL2, the special investigations carried out on the CO{sub 2} coolant of this pile, and the information gained during normal operation and during accidents. The DCCA - CO{sub 2} which has just been put in operation at G2 is briefly presented. In the conclusion the possibilities offered by this apparatus are underlined. (author) [French] Ce rapport a pour but de presenter le Dispositif de Controle continu de l'Activite du CO{sub 2} pouvant etre utilise aupres des piles refroidies par une circulation de gaz. La premiere partie du rapport consiste essentiellement a decrire l'ensemble de l'appareillage mis en oeuvre, a preciser la nature des mesures de radioactivite et de thermodynamique effectuees et a citer les caracteristiques generales du circuit de gaz pour avoir un dispositif presentant une etancheite efficace

  6. The work of the ILO in the field of protection of workers against ionising and non-ionising radiations

    Coppee, G.H.

    1980-01-01

    A chronological account since 1934 of the activities of the International Labour Organization (ILO) in the protection of workers against risks due to ionising and non-ionising radiations is given. Several ILO publication on safety standards and codes of practice for protection against mainly ionising radiation in various occupational situations are indicated. A more intensive study by the ILO on the protection of workers against non-ionising radiation was proposed for 1980-81. (UK)

  7. The ENEA calibration service for ionising radiations

    Monteventi, F.; Sermenghi, I.

    1999-01-01

    The report describes all the facilities available at the the service of the ENEA Calibration Service for Ionising Radiations at Bologna (Italy). It gives a detailed description of all equipments qualified for photon fields metrology including the secondary standards and the calibration procedures performed for radiation monitoring devices and dosemeters [it

  8. Contribution to the detection of radioactivity as applied to regular testing and to protection; Contribution a la detection des rayonnements en vue du controle et de la protection

    Fuhrmann,; Joffre,; Savouyaud, [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    problemes les plus urgents concernaient la dosimetrie des rayonnements et la constitution d'un materiel electronique nombreux, donc assez bon marche, autant que possible. 3. Danspresente communication, nous exposerons sommairement notre contribution dans ce domaine et particulierement: - l'amelioration des methodes de dosimetrie {gamma} par films photographiques, - l'essai d'une technique simple et peu couteuse pour la dosimetrie et la spectrometrie {alpha}, - l'orientation donnee aux nouveaux materiels electroniques: chambre d'ionisation, compteurs, scintillateurs, - la mise au point d'un materiel special permettant de mesurer la valeur moyenne d'un flux de particules emis periodiquement pendant un temps tres court. (auteur)

  9. Organisation et mise en oeuvre d'une infrastructure reglementaire nationale chargee de la protection contre les rayonnements ionisants et de la surete des sources de rayonnements. Rapport interimaire pour observations

    2001-11-01

    A number of IAEA Member States are undertaking to strengthen their radiation protection and safety infrastructures in order to facilitate the adoption of the requirements established in the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (the Standards). In this connection, the IAEA has developed a technical co-operation programme (Model Project on Upgrading Radiation Protection Infrastructure) to improve radiation protection and safety infrastructures in 51 Member States, taking into account national profiles and needs of the individual participating, countries. The present report deals with the elements of a regulatory infrastructure for radiation protection and safety and intends to facilitate the, implementation of the Basic Safety Standards in practice. It takes into account the proposals in an earlier report, IAEA-TECDOC-663, but it has been expanded to include enabling legislation and modified to be more attuned to infrastructure issues related to implementation of the Standards. The orientation is toward infrastructures concerned with protection and safety for radiation sources used in medicine, agriculture, research, industry and education rather than infrastructures for protection and safety for complex nuclear facilities. It also discusses options for enhancing the effectiveness and efficiency of the infrastructure in accordance with the size and scope of radiation practices and available regulatory resources within a country

  10. Surveillance of health care workers exposed to ionising radiation: Rimed pilot study

    2008-01-01

    The project so-called RIMED aimed to set up epidemiological surveillance of health care workers exposed to ionizing radiation. A pilot study was conducted in a sample of hospital personnel to examine the possibility of identifying exposed subjects in order to analyse mortality patterns according to occupational characteristics such as medical departments or occupations in a historical cohort. Seven hospitals participated in this pilot study. Health-care workers who had worn a dosimeter up to December 2003 were to be included in this cohort. The subjects' identification data were obtained from the SISERI (Systeme d'information de la surveillance de l'exposition aux rayonnements ionisants - Ionizing Radiation Exposure Monitoring Information System) database managed by the Institut de radioprotection et de surete nucleaire - Radiation Protection and Nuclear Safety Institute (IRSN). The SISERI system was in a 'pilot' phase in 2004. According to SISERI database, a total of 5126 subjects were found to have worn a dosimeter up to December 2003. The subjects' identification data were completed by the administrative services of the hospitals and occupational physicians searched for subjects' occupational data. Information required for the vital status search was satisfactorily completed only for 38% of the cohort subjects. This pilot study showed that obtaining data from SISERI database completed by hospital administrative data in 2004 led to a database of insufficient quality for epidemiological surveillance. The Institut de veille sanitaire (French Institute of Public Health Surveillance) recommends that transmission by the employers of some specific personal or occupational data of the exposed subjects should be made compulsory. In this way, SISERI system should be able to constitute any database with required quality for epidemiological surveillance of ionizing radiation exposed subjects. (authors)

  11. Critical ionisation velocity effects in astrophysical plasmas

    Raadu, M.A.

    1979-08-01

    Critical ionisation velocity effects are relevant to astrophysical situations where neutral gas moves through a magnetised plasma. The experimental significance of the critical velocity is well established and the physical basis is now becoming clear. The underlying mechanism depends on the combined effects of electron impact ionisation and electron energisation by collective plasma interactions. For low density plasmas a theory based on a circular process involving electron heating through a modified two stream instability has been developed. Several applications of critical velocity effects to astrophysical plasmas have been discussed in the literature. The importance of the effect in any particular case may be determined from a detailed consideration of energy and momentum balance, using appropriate atomic rate coefficients and taking full account of collective plasma processes. (Auth.)

  12. A new thermal ionisation mass spectrometer

    Haines, C.; Merren, T.O.; Unsworth, W.D.

    1979-01-01

    The Isomass 54E, a new thermal ionisation mass spectrometer for precise measurements of isotopic composition is described in detail. It combines the fruits of three development pro ects, viz. automation, energy filters and extended geometry with existing micromass expertise and experience. The hardware and software which are used for the automation as well as the energy filter used, are explained. The 'extended geometry' ion optical system adopted for better performance is discussed in detail. (K.B.)

  13. Medical response to effects of ionising radiation

    Crosbie, W.A.; Gittus, J.H.

    1989-01-01

    The proceedings of a conference on 'Medical Response to Effects of Ionising Radiation' in 1989 in the form of nineteen papers published as a book. Topics discussed include radiation accidents at nuclear facilities, the medical management of radiation casualties, the responsibilities, plans and resources for coping with a nuclear accident and finally the long term effects of radiation, including leukaemia epidemiology studies. All papers were selected and indexed separately. (UK)

  14. Antioxidant Protection in Blood against Ionising Radiation

    Bognar, G.; Meszaros, G.; Koteles, G. J.

    2001-01-01

    Full text: The quantities of the antioxidants in the human blood are important indicators of health status. The routine determinations of activities/capacities of antioxidant compounds would be of great importance in assessing individual sensitivities against oxidative effects. We have investigated the sensitivities of those antioxidant elements against various doses of ionising radiation tested by the RANDOX assays. Our results show dose-dependent decreases of antioxidant activities caused by the different doses. The total antioxidant status value linearly decreased up to 1 Gy, but further increase of dose (2 Gy) did not influence the respective values although the test system still indicated their presence. It means that the human blood retains 60-70% of its total antioxidant capacity. Radiation induced alterations of the antioxidant enzymes: glutathione peroxidase and superoxide dismutase have been also investigated. The activities of glutathione peroxidase and superoxide dismutase decreased linearly upon the effects of various doses of ionising radiation till 1 Gy. Between 1 and 2 Gy only further mild decreases could be detected. In this case the human blood retained 40-60% of these two antioxidant enzymes. These observations suggest either the limited response of antioxidant system against ionising radiation, or the existence of protection system of various reactabilities. (author)

  15. European Code against Cancer 4th Edition: Ionising and non-ionising radiation and cancer.

    McColl, Neil; Auvinen, Anssi; Kesminiene, Ausrele; Espina, Carolina; Erdmann, Friederike; de Vries, Esther; Greinert, Rüdiger; Harrison, John; Schüz, Joachim

    2015-12-01

    Ionising radiation can transfer sufficient energy to ionise molecules, and this can lead to chemical changes, including DNA damage in cells. Key evidence for the carcinogenicity of ionising radiation comes from: follow-up studies of the survivors of the atomic bombings in Japan; other epidemiological studies of groups that have been exposed to radiation from medical, occupational or environmental sources; experimental animal studies; and studies of cellular responses to radiation. Considering exposure to environmental ionising radiation, inhalation of naturally occurring radon is the major source of radiation in the population - in doses orders of magnitude higher than those from nuclear power production or nuclear fallout. Indoor exposure to radon and its decay products is an important cause of lung cancer; radon may cause approximately one in ten lung cancers in Europe. Exposures to radon in buildings can be reduced via a three-step process of identifying those with potentially elevated radon levels, measuring radon levels, and reducing exposure by installation of remediation systems. In the 4th Edition of the European Code against Cancer it is therefore recommended to: "Find out if you are exposed to radiation from naturally high radon levels in your home. Take action to reduce high radon levels". Non-ionising types of radiation (those with insufficient energy to ionise molecules) - including extremely low-frequency electric and magnetic fields as well as radiofrequency electromagnetic fields - are not an established cause of cancer and are therefore not addressed in the recommendations to reduce cancer risk. Copyright © 2015 International Agency for Research on Cancer. Published by Elsevier Ltd. All rights reserved.

  16. Food ionisation. Realities and perspectives; L'ionisation alimentaire. Realites et perspectives

    Bonnet, G

    1994-06-01

    The ionisation of food is a treatment using a certain type of energy. the radiations used in the industrial treatments are limited to three sources. The gamma radiations, the x radiations and the electrons beams emitted with accelerators. The physical treatments by ionizing radiations have for aim to cleanse and to increase the conservation time of food. Now, the applications in agriculture and food industry, are still marginal. The industrial using ionisation are these ones that did not find any alternative decontamination method. The barriers are more scientific or technical or economical than a question of regulation or behaviour. (N.C.)

  17. Food ionisation. Realities and perspectives; L'ionisation alimentaire. Realites et perspectives

    Bonnet, G

    1994-06-01

    The ionisation of food is a treatment using a certain type of energy. the radiations used in the industrial treatments are limited to three sources. The gamma radiations, the x radiations and the electrons beams emitted with accelerators. The physical treatments by ionizing radiations have for aim to cleanse and to increase the conservation time of food. Now, the applications in agriculture and food industry, are still marginal. The industrial using ionisation are these ones that did not find any alternative decontamination method. The barriers are more scientific or technical or economical than a question of regulation or behaviour. (N.C.)

  18. The ionisation balance of C0 to C+4

    Nussbaumer, H.; Storey, P.J.

    1975-01-01

    The ionisation balance for the ions C 0 -C +4 has been calculated for 10 8 -3 ] 12 and 2 x 10 4 K 5 K. The presence of metastable terms is included in the calculation of the collisional dielectronic recombination and ionisation coefficients. The influence of the observed solar radiation field on the ionisation balance is investigated. Changes in that field do strongly influence the results. (orig.) [de

  19. Ionizing radiation M.O.S. dosimeters: sensibility and stability; Dosimetres M.O.S. de rayonnements ionisants: sensibilite et stabilite

    Gessinn, F

    1993-12-01

    This thesis is a contribution to the study of the ionizing radiation responsivity of P.O.M.S. dosimeters. Unlike the development of processing hardening techniques, our works goal were to increase, on the one hand, the M.O.S. dosimeters sensitivity in order to detect small radiation doses and on the other hand, the stability with time and temperature of the devices, to minimize the absorbed-dose estimation errors. With this aim in mind, an analysis of all processing parameters has been carried out: the M.O.S. dosimeter sensitivity is primarily controlled by the gate oxide thickness and the irradiation electric field. Thus, P.M.O.S. transistors with 1 and 2 {mu}m thick silica layers have been fabricated for our experiments. The radiation response of our devices in the high-field mode satisfactorily fits a D{sub ox}{sup 2} power law. The maximum sensitivity achieved (9,2 V/Gy for 2{mu}m devices) is close to the ideal value obtained when considering only an unitary carrier-trapping level, and allows to measure about 10{sup -2} Gy radiation doses. Read-time stability has been evaluated under bias-temperature stress conditions: experiments underscore slow fading, corresponding to 10{sup -3} Gy/h. The temperature response has also been studied: the analytical model we have developed predicts M.O.S. transistors threshold voltage variations over the military specifications range [-50 deg. C, + 150 deg. C]. Finally, we have investigated the possibilities of irradiated dosimeters thermal annealing for reusing. It appears clearly that radiation-induced damage annealing is strongly gate bias dependent. Furthermore, dosimeters radiation sensitivity seems not to be affected by successive annealings. (author). 146 refs., 58 figs., 9 tabs.

  20. Prevention of risks in relation with occupational exposure to ionizing radiation; Prevention des risques lies a l'exposition professionnelle aux rayonnements ionisants

    NONE

    2005-07-01

    After remind the base notions in the field of ionizing radiation, this file evaluates the situation on the natural and occupational exposures: modes, sources, and exposure level, risk for health. It presents the principles of prevention allowing in a professional area (out of nuclear industry) to reduce and control these exposures. Some practical cases illustrate the radiation protection approach. references are given: regulatory benchmarks, useful links, books to consult. (N.C.)

  1. Characterization and pharmacological modulation of intestinal inflammation induced by ionizing radiation; Caracterisation et modulation pharmacologique de l'inflammation intestinale induite par les rayonnements ionisants

    Gremy, O

    2006-12-15

    The use of radiation therapy to treat abdominal and pelvic malignancies inevitably involves exposure of healthy intestinal tissues which are very radiosensitive. As a result, most patients experience symptoms such as abdominal pain, nausea and diarrhea. Such symptoms are associated with acute damage to intestine mucosa including radio-induced inflammatory processes. With a rat model of colorectal fractionated radiation, we have shown a gradual development of a colonic inflammation during radiation planning, without evident tissue injury. This radio-induced inflammation is characterized not only by the sur expressions of pro-inflammatory cytokines and chemokines, a NF-kB activation, but also by a repression of anti-inflammatory cytokines and the nuclear receptors PPARa and RXRa, both involved in inflammation control. This early inflammation is associated with a discreet neutrophil recruitment and a macrophage accumulation. Macrophages are still abnormally numerous in tissue 27 weeks after the last day of irradiation. Inflammatory process is the most often related to a specific immune profile, either a type Th1 leading to a cellular immune response, or a type Th2 for humoral immunity. According to our studies, a unique abdominal radiation in the rat induces an ileum inflammation and an immune imbalance resulting in a Th2-type profile. Inhibiting this profile is important as its persistence promotes chronic inflammation, predisposition to bacterial infections and fibrosis which is the main delayed side-effect of radiotherapy. The treatment of rats with an immuno-modulator compound, the caffeic acid phenethyl ester (C.A.P.E.), have the potential to both reduce ileal mucosal inflammation and inhibit the radio-induced Th2 status. In order to search new therapeutic molecular target, we has been interested in the PPARg nuclear receptor involved in the maintenance of colon mucosal integrity. In our abdominal irradiation model, we have demonstrated that the prophylactic treatment with a PPARg synthetic ligand, the so-called 5-aminosalicylic acid (5-ASA), protects against the development of the acute mucosal colon inflammation. This pharmacological drug restrains radio-induced expression of pro inflammatory molecular actors such as TNFa, MCP-1 and iNOS, it also limits the repression of nuclear receptors involved in inflammation control such as PPARg, and reduces the radio-induced accumulation of macrophages. These results could give some leads to find therapeutic drug to limit radio-induced early mucosal and consequently, to improve patients' comfort during and after the radiotherapy schedule. (author)

  2. Characterization and pharmacological modulation of intestinal inflammation induced by ionizing radiation; Caracterisation et modulation pharmacologique de l'inflammation intestinale induite par les rayonnements ionisants

    Gremy, O

    2006-12-15

    The use of radiation therapy to treat abdominal and pelvic malignancies inevitably involves exposure of healthy intestinal tissues which are very radiosensitive. As a result, most patients experience symptoms such as abdominal pain, nausea and diarrhea. Such symptoms are associated with acute damage to intestine mucosa including radio-induced inflammatory processes. With a rat model of colorectal fractionated radiation, we have shown a gradual development of a colonic inflammation during radiation planning, without evident tissue injury. This radio-induced inflammation is characterized not only by the sur expressions of pro-inflammatory cytokines and chemokines, a NF-kB activation, but also by a repression of anti-inflammatory cytokines and the nuclear receptors PPARa and RXRa, both involved in inflammation control. This early inflammation is associated with a discreet neutrophil recruitment and a macrophage accumulation. Macrophages are still abnormally numerous in tissue 27 weeks after the last day of irradiation. Inflammatory process is the most often related to a specific immune profile, either a type Th1 leading to a cellular immune response, or a type Th2 for humoral immunity. According to our studies, a unique abdominal radiation in the rat induces an ileum inflammation and an immune imbalance resulting in a Th2-type profile. Inhibiting this profile is important as its persistence promotes chronic inflammation, predisposition to bacterial infections and fibrosis which is the main delayed side-effect of radiotherapy. The treatment of rats with an immuno-modulator compound, the caffeic acid phenethyl ester (C.A.P.E.), have the potential to both reduce ileal mucosal inflammation and inhibit the radio-induced Th2 status. In order to search new therapeutic molecular target, we has been interested in the PPARg nuclear receptor involved in the maintenance of colon mucosal integrity. In our abdominal irradiation model, we have demonstrated that the prophylactic treatment with a PPARg synthetic ligand, the so-called 5-aminosalicylic acid (5-ASA), protects against the development of the acute mucosal colon inflammation. This pharmacological drug restrains radio-induced expression of pro inflammatory molecular actors such as TNFa, MCP-1 and iNOS, it also limits the repression of nuclear receptors involved in inflammation control such as PPARg, and reduces the radio-induced accumulation of macrophages. These results could give some leads to find therapeutic drug to limit radio-induced early mucosal and consequently, to improve patients' comfort during and after the radiotherapy schedule. (author)

  3. Synthesis and evaluation of new protecting agents against ionizing radiations; Synthese et evaluation de nouveaux agents de protection contre les rayonnements ionisants

    Nadal, B.

    2009-10-15

    This thesis is devoted to the synthesis of new pulvinic acid derivatives and the evaluation of their antioxidant and radioprotective properties. This study has been conducted with the aim to develop new protecting agents against ionizing radiations. A new access to pulvinic acid derivatives was developed starting from L-dimethyl tartrate. It is based on a Dieckmann cyclization a dehydration and a Suzuki-Miyaura coupling. It allows a short effective preparation of various pulvinic acid derivatives: tetronic acid derivatives, mono-substituted pulvinic acid derivatives and methyl pulvinates. A modified method has been used to prepare pulvinones. This strategy gave access in four steps to the desired pulvinones. The rapidity of this method is provided by a tandem process, carried out in the final step, involving a Dieckmann cyclization and a {beta}-elimination. A synthesis of 3-aryltetramic acids has also been developed in order to prepare nitrogen derivatives of pulvinic acid. The antioxidant activity of the prepared compounds was then evaluated using various tests: DPPH, ABTS, protection of thymidine and DNA study of lipid peroxidation. These evaluations allowed to define interesting structure-activity relationships of pulvinic derivatives. They have shown that several derivatives have very good antioxidant activities. Finally, radioprotective tests on TK6 cells and mice have have been performed on selected compounds. (author)

  4. Action of the ionization treatment on the soft cheeses made from unpasteurized milk. Action des rayonnements ionisants sur les fromages a pate molle fabriques au lait cru

    Chincholle, R.

    1991-01-01

    The works made on cheeses manufactured with unpasteurized milk, camembert type, have shown that it is possible to use irradiation for their sanitation. The treatment by ionization from 2 to 3 kGy of a cheese made from unpasteurized milk permits the reduction from 10{sup 3} to 10{sup 5} of the bacteria: faecal coliforms, staphylococcus and other indesirable bacteria. The works made by the scientists, J.F. Diell, C. Hauchmann, D. Rilcast, proved that ionization of food has no bad consequences in the nutritional field. Regarding the cheeses made with raw milk this technic brings to the consumer a higher bacteriological security.

  5. Ionising energy treatment of fresh fruit

    Rigney, C.J.

    1985-01-01

    The main purposes of the ionising energy treatment of fresh fruit are: the extension of shelf life of the commodity due to a direct physiological effect on the particular product; the extension of shelf life of the commodity due to a reduction in the development of moulds and rots which would normally render the product worthless; and the killing of insect pests of quarantine significance, to allow for normal marketing of fresh fruit without the risk of introducing insect pests to previously pest-free areas

  6. The ionisation equation in a relativistic gas

    Kichenassamy, S.; Krikorian, R.A.

    1983-01-01

    By deriving the relativistic form of the ionisation equation for a perfect gas it is shown that the usual Saha equation is valid to 3% for temperatures below one hundred million Kelvin. Beyond 10 9 K, the regular Saha equation is seriously incorrect and a relativistic distribution function for electrons must be taken into account. Approximate forms are derived when only the electrons are relativistic (appropriate up to 10 12 K) and also for the ultrarelativistic case (temperatures greater than 10 15 K). (author)

  7. Ionising radiation: a guide to the Regulations

    Hughes, Donald.

    1986-01-01

    The author explains the basic requirements on health and safety personnel in relation to the Ionising Radiations Regulations 1985. The outline paper is presented under the following headings: Dose assessment, Interpretation and general regulations 1-5, Dose limitation regulations 6 and 7, Regulation of work - regulations 8-12, Dosimetry and medical surveillance - regulations 13-17, summary of records to be kept, entry to controlled areas, Control of radioactive substances -regulations 18-23, Monitoring of radiation regulation 24, Assessments and notifications - regulations 25-31, Safety of articles and equipment - regulations 32-34, Other guidance. (U.K.)

  8. Ionising radiation and trans-generational instability

    Vrhovac, I.; Niksic, G.

    2007-01-01

    Indirect monitoring of the impact posed by ionising radiation to the genome instability of the descendants, consequent to the irradiation of one of their parents, boils down to the investigation of changes occurring exclusively in the mini-satellite loci of the cells constituting the gametal developmental line. The resultant mini-satellite mutations are expressed in their percentages, and equal to the ratio of the number of mutated alleles in that particular generation over the total number of alleles present. The impact of ionising radiation to the irradiated parent's offspring was first noticed on haematopoietic mouse stem-cells. Even though an irradiated cell of a female parent lacks any mutations whatsoever, daughter cells present with the increased mutation rates. The observed phenomenon of the so called trans-generational instability has been defined as the occurrence of mutations in the genome of individuals originating from the irradiated ancestors. Due to the aforementioned, one can conclude that these mutations need not be present in the irradiated parental cells, and do not necessarily vanish in the next few generations, but may result in the increase in mutation rates observed in the latter. The results of the investigations performed on the animal model, as well as of those carried out in human population, point to the occurrence of significant changes to be found on mini-satellite loci of the descending generation, while the mechanism underlying those changes hasn't been completely clarified yet, and, therefore, calls for the further investigation. (author)

  9. Effects of the ionising radiations on the structure and the function of the intestinal epithelial cell; Effets des rayonnements ionisants sur la structure et la fonction de la cellule epitheliale intestinale

    Haton, C

    2005-06-15

    The intestinal mucosa is a particularly radio-sensitive tissue and damage may occur following either accidental or therapeutic exposure. the deleterious actions of ionizing radiation are linked to the formation of sometimes overwhelming quantities of reactive oxygen species (R.O.S.). Production of R.O.S. is both direct and indirect from the secondary effects of irradiation. A better comprehension of the underlying mechanisms of injury will lead to more adapted therapeutic approaches to limit the harmful effects of irradiation. The homeostasis of the intestinal epithelium is regulated by three factors: proliferation, apoptosis and differentiation. these three factors were studied using the cell model, HT29, in order to analyze modulations of this balance after irradiation. our results, in agreement with other data, showed the establishment of mitotic delay. This arrest of proliferation was followed by apoptosis to be the major mechanism leading to cell death in this model. thus, for the first time, we have shown that irradiated intestinal epithelial cells preserve their capacity to differentiate. This indicates, although indirectly, that intestinal cells have and preserve an intrinsic capacity restore a functional epithelium. R.O.S. are considered as intermediates between the physical nature of radiations and biological responses. It seems essential to understand anti-oxidant mechanisms used by the cell for defence against the deleterious effects of R.O.S post exposure. This study of several anti-oxidant defence mechanisms of intestinal mucosa, was carried out in vivo in the mouse at different times following abdominal irradiation. We observed an early mitochondrial response in the hours following irradiation revealing this organelle as a particular target. We demonstrated a strong alteration of anti-oxidant capacity as revealed by a decrease in S.O.D.s, catalase and an increase of the G.P.X.s and M.T.s. A part of these modifications appeared to depend on an irradiation-induced inflammatory response. Finally, we showed that the loss of catalase is linked to the onset of structural damage to the mucosa. All of these results orient therapeutic strategies towards inducing the proliferation of crypt cells, rather than an inhibition of apoptosis, since the epithelial cells retain differentiation capacity and so production of functional cells. (aut0009h.

  10. Contribution to the study and use of ionisation chambers for nuclear reactor control (1965); Contribution a l'etude et a l'utilisation des chambres d'ionisation pour le controle des reacteurs nucleaires (1965)

    Duchene, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-02-15

    high-power reactors. (author) [French] Les chambres d'ionisation sont actuellement les detecteurs les mieux adaptes au controle des reacteurs nucleaires par des mesures neutroniques. Nous avons cru bon de rappeler quelques generalites concernant la dynamique des reacteurs, les differents procedes de detection des neutrons, le fonctionnement des chambres d'ionisation et les methodes de mesure utilisees. Notre contribution aux techniques de controle des reacteurs consiste d'une part en une tentative de synthese des facteurs intervenant dans le fonctionnement des chambres d'ionisation, l'etude de ces facteurs, et d'autre part l'elaboration de chambres d'ionisation a fission et a bore permettant de suivre la marche d'un reacteur du demarrage jusqu'a la puissance maximale. Dans le domaine des chambres a fission, nous avons en particulier ameliore les techniques de depot d'oxyde d'uranium sur l'aluminium et realise la mise au point de depots par electrolyse sur d'autres metaux: acier inoxydable, cuivre, molybdene, nickel, tantale, titane, kovar, tungstene et beryllium. Nous avons elabore plusieurs types de chambres a fission servant au demarrage des reacteurs: un type de performances moyennes actuellement utilise dans les piles francaises un type a haute sensibilite un type a haute temperature qui a fonctionne jusqu'a 600 deg. C. En ce qui concerne les chambres a bore, nous avons etudie les perturbations apportees dans les mesures par l'exposition des chambres a d'importants flux de neutrons et a un rayonnement {gamma} intense. Cette exposition produit une modification des proprietes des materiaux constitutifs et la production dans les chambres d'un bruit de fond qui peut gener considerablement les mesures neutroniques. Nous avons montre que la technique de compensation permettait de limiter l'importance de ce bruit de fond et d'augmenter ainsi la plage de fonctionnement des chambres d'ionisation classiques destinees aux mesures de puissance. Enfin, nous avons realise deux

  11. Immunosuppression by non-ionising and ionising radiation - are there similarities?

    Reeves, V.

    2003-01-01

    Solar UV radiation, the ubiqitous environmental non-ionising radiation, initiates its immunomodulating effects almost entirely in the skin. In direct contrast, ionising radiation penetrates much more efficiently, and has a multitude of internal targets throughout the body. As a consequence, the mechanisms underlying UV-induced immunosuppression have been more readily characterised, whereas surprisingly little is known about immunosuppression resulting from ionising radiation. Photoimmunological studies in mice during the past 20-30 years have established the action spectrum for UV-induced immunosuppression, implicating the UVB waveband, 290-320 nm. Controversy rages over the immunosuppressive potential of the UVA waveband, 320-400 nm, but we demonstrate that environmentally relevant doses of UVA not only are immunologically innocuous, but provide protection against UVB-immunosuppression. Increasingly larger UVA exposures increasingly immunosuppress mice. The UVA immunoprotective effect is strongly dependent on the induction of a cutaneous redox-regulated enzyme, haem oxygenase (heat shock protein 32) that is known to protect cells from oxidative stress, and it is consistent that a number of exogenous antioxidants (vitamin E, vitamin C, green tea polyphenols, isoflavones) can protect effectively from photoimmuno-suppression. Thus the UV-immunosuppressed state is promoted by oxidative damage and depletion of endogenous antioxidant molecules. It is also associated with cutaneous cytokine derangements, such that Th-2 cytokines (IL-4, IL-10) are increased at the expense of Th-1 cytokines (IFN-gamma, IL-12), and with histamine and inflammatory prostaglandin activity. In contrast, immunoprotective UVA irradiation protects the cutaneous cytokine array, inhibits IL-10 upregulation and increases IFN-gamma and IL-12 expression. On the other hand, while ionising radiation is known to cause immunosuppression, large doses target the bone marrow and haemopoiesis lethally and

  12. Exotic highly ionising particles at the LHC

    De Roeck, A; Mermod, P; Milstead, D; Sloan, T

    2012-01-01

    The experiments at the Large Hadron Collider (LHC) are able to discover or set limits on the production of exotic particles with TeV-scale masses possessing values of electric and/or magnetic charge such that they appear as highly ionising particles (HIPs). In this paper the sensitivity of the LHC experiments to HIP production is discussed in detail. It is shown that a number of different detection methods are required to investigate as fully as possible the charge-mass range. These include direct detection as the HIPs pass through detectors and, in the case of magnetically charged objects, the so-called induction method with which monopoles which stop in accelerator and detector material could be observed. The benefit of using complementary approaches to HIP detection is discussed.

  13. The XUV spectra of highly ionised molybdenum

    Mansfield, M.W.D.; Peacock, N.J.; Smith, C.C.; Hobby, M.G.; Cowan, R.D.

    1978-01-01

    The spectra of molybdenum ions produced in Tokamaks in the wavelength range 10-200 A have been reproduced in a plasma formed by laser beam irradiation of solid molybdenum targets. Lines from highly ionised stages of molybdenum (Mo XXX to Mo XXXII) have been distinguished by varying the laser beam intensity. Detailed analyses of the simpler ions, Mo XV (Ni-like), Mo XVI (Co-like), Mo XXXII (Na-like), and to a lesser extent Mo XXXI (Mg-like) and Mo XVII (Fe-like), have been achieved by comparison with ab initio calculations. A general interpretation of intermediate ion stages is also given but it is shown that most of these spectra are so complex, as a result of inner-subshell excitation, that detailed term-scheme analyses are nearly impossible. (author)

  14. Effects of intense stratospheric ionisation events

    Reid, G.C.; McAfee, J.R.; Crutzen, P.J.

    1978-01-01

    High levels of ionising radiation in the Earth's stratosphere will lead to increased concentrations of nitrogen oxides and decreased concentrations of ozone. Changes in the surface environment will include an increased level, of biologically harmful UV radiation, caused by the ozone depletion, and a decreased level of visible solar radiation, due to the presence of major enhancements in the stratospheric concentration of nitrogen dioxide. These changes have been studied quantitatively, using the passage of the Solar System through a supernova remnant shell as an example. Some of the potential environmental changes are a substantial global cooling, abnormally dry conditions, a reduction in global photosynthesis and a large increase in the flux of atmospheric fixed nitrogen to the surface of the Earth. Such events might have been the cause of mass extinctions in the distant past. (Author)

  15. XUV spectra of highly ionised molybdenum

    Mansfield, M W.D.; Peacock, N J; Smith, C C; Hobby, M G [UKAEA, Abingdon. Culham Lab.; Cowan, R D

    1978-05-14

    The spectra of molybdenum ions produced in Tokamaks in the wavelength range 10-200 A have been reproduced in a plasma formed by laser beam irradiation of solid molybdenum targets. Lines from highly ionised stages of molybdenum (Mo XXX to Mo XXXII) have been distinguished by varying the laser beam intensity. Detailed analyses of the simpler ions, Mo XV (Ni-like), Mo XVI (Co-like), Mo XXXII (Na-like), and to a lesser extent Mo XXXI (Mg-like) and Mo XVII (Fe-like), have been achieved by comparison with ab initio calculations. A general interpretation of intermediate ion stages is also given but it is shown that most of these spectra are so complex, as a result of inner-subshell excitation, that detailed term-scheme analyses are nearly impossible.

  16. On the honeybee resistance to gamma radiation; Sur la resistance au rayonnement gamma de l'abeille ouvriere

    Courtois, G.; Lecomte, J. [Commissariat a l' energie atomique et aux energies alternatives - CEA, Section des Applications des Radioelements, Centre d' Etudes Nucleaires, Saclay, Station de Recherches Apicoles, Bures-sur-Yvette (France)

    1960-07-01

    The honeybee, when irradiated by gamma radiations from a cobalt-60 source can stand a 18000 r dose without any apparent harm. Noticeable harm is observed for 90000 r. while immediate death of 100% of the individuals is obtained with a 200000 r dose. The physiological condition of the honeybee plays an important role in its resistance to gamma radiation. Reprint of a paper published in Annales de l'abeille, IV, 1959, p. 285-290 [French] L'Abeille butineuse irradiee par le rayonnement gamma issu d'une source de Cobalt 60 supporte sans dommages apparents une dose de 18000 r. Des dommages tres appreciables sont observes pour 90000 r. Une dose de 200000 r entraine la mort immediate de 100% des individus. L'etat physiologique de l'Abeille joue un role important dans la resistance au rayonnement gamma. Reproduction d'un article publie dans Annales de l'abeille, IV, 1959, p. 285-290.

  17. Innershell ionisation at small impactparameters in proton-atom collisions

    Duinker, W.

    1981-01-01

    This thesis concentrates on innershell ionisation in proton-atom collisions. An experiment on K-shell ionisation of argon is described, performed in a gasfilled collision chamber under single collision conditions. Further experiments with carbon and aluminium were performed, the K-shell vacancy production in the collision of protons with these atoms being detected through the measurement of Auger-electrons. A spectrometer with a large solid angle was specially constructed for this and its performance is described. K-shell ionisation accompanying nuclear (p,γ) reactions has also been measured using 26 Mg and 27 Al. (Auth./C.F.)

  18. Noyaux et radioactivité une introduction à la physique des particules et à la physique nucléaire

    Debu, Pascal

    2017-01-01

    Nées au début du XXe siècle, la physique nucléaire et la physique des particules ont bouleversé notre vision du monde et révolutionné la société par leurs innombrables applications : l'énergie nucléaire et l'utilisation des rayonnements pour la médecine et les sciences des matériaux en sont des exemples emblématiques. L'objectif de cet ouvrage est de permettre au lecteur d'appréhender les phénomènes nucléaires et la physique des hautes énergies, d'illustrer les retombées de la physique fondamentale dans la société, et d'éveiller ainsi la curiosité et l'intérêt pour ces disciplines. Le premier chapitre rappelle les notions indispensables de mécanique quantique et de relativité restreinte. Il se termine par une introduction sur l'antimatière et ses applications. Le deuxième chapitre aborde la physique des particules par la description des constituants de la matière et des lois qui gouvernent leurs interactions. L'interaction faible est l'occasion de développements sur les notions...

  19. Health Services management. Health Service use of ionising radiations

    1989-12-01

    This circular consolidates and updates advice on the statutory and management responsibilities of Health Authorities in relation to the use of ionising radiations (including radioactive substances) on premises controlled by them and/or by persons employed by them (author)

  20. Working Group on Ionising Radiations. Report 1987-88

    1989-01-01

    The programme of work for 1987/88 by the Working Group on Ionising Radiation, Health and Safety Commision in February 1988, included the main topics of continuing interest and concern in relation to ionising radiations in general and the Ionising Radiations Regulations 1985 (IRR 85) (Ref 1) in particular. These were: emergency dose limitation, occupational dose limitation, practical experience of the principle of keeping doses as low as reasonably practicable, experience of the regulatory requirements in respect of internal dosimetry and the need for a standing advisory committee on ionising radiations. Calibration of radiotherapy equipment was also considered as a matter of principle following a specific incident involving cancer patients. This report of progress during the first year summarises the Group's opinions on each topic and gives recommendations. (author)

  1. Effects of small doses of ionising radiation

    Doll, R.

    1998-01-01

    Uncertainty remains about the quantitative effects of doses of ionising radiation less than 0.2 Sv. Estimates of hereditary effects, based on the atomic bomb survivors, suggest that the mutation doubling dose is about 2 Sv for acute low LET radiation, but the confidence limits are wide. The idea that paternal gonadal irradiation might explain the Seascale cluster of childhood leukaemia has been disproved. Fetal irradiation may lead to a reduction in IQ and an increase in seizures in childhood proportional to dose. Estimates that doses to a whole population cause a risk of cancer proportional to dose, with 0.1 Sv given acutely causing a risk of 1%, will need to be modified as more information is obtained, but the idea that there is a threshold for risk above this level is not supported by observations on the irradiated fetus or the effect of fallout. The idea, based on ecological observations, that small doses protect against the development of cancer is refuted by the effect of radon in houses. New observations on the atomic bomb survivors have raised afresh the possibility that small doses may also have other somatic effects. (author)

  2. Application of radioactivity to subterranean hydraulic engineering (1961); Application de la radioactivite a l'hydraulique souterraine (1961)

    Hours, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    , des techniques originales ont ete imaginees pour les mesures de debits, de capacite de reservoir, de porosite et de permeabilite. En outre, des techniques basees sur l'absorption et la diffusion des rayons {gamma} et des neutrons ont ete developpees pour la mesure de la densite, de l'humidite et de la porosite des terrains, ainsi que pour leur analyse. C'est a l'etude das formations petroliferes que la radioactivite a ete jusqu'ici le plus appliquee. Par ailleurs, l'etude de la distribution du tritium d'origine naturelle ou thermonucleaire a fourni une importante contribution a la connaissance du cycle hydrologique. (auteur)

  3. Study of cerenkov radiation. Production of {gamma} rays by electron accelerators; Etude du rayonnement de freinage. Production de rayons {gamma} par des accelerateurs d'electrons

    Bernard, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    This study is a critical comparison of the theories of Bremsstrahlung. Experimental results obtained by the production of {gamma} radiation with electron accelerators are compared to the theoretical results in order to estimate the extent to which the various theories are valid. (author) [French] Cette etude est une synthese des theories du rayonnement de freinage. Des resultats experimentaux, obtenus par la production de rayonnements {gamma} avec des accelerateurs d'electrons, sont compares aux resultats theoriques afin d'evaluer les domaines de validite des diverses theories. (auteur)

  4. Introducing Biological Microdosimetry for Ionising Radiation

    Scott, B.R.; Schoellnberger, H.

    2000-01-01

    Microdosimetry is important for radiation protection, for understanding mechanisms of radiation action, and for radiation risk assessment. This article introduces a generic, Monte Carlo based approach to biological microdosimetry for ionising radiation. Our Monte Carlo analyses are carried out with a widely used Crystal Ball software. The approach to biological microdosimetry presented relates to quantal biological effects data (e.g. cell survival, mutagenesis, neoplastic transformation) for which there is an initial linear segment to the dose-response curve. The macroscopic dose data considered were selected such that is could be presumed that the vast majority of cells at risk have radiation dose delivered to their critical target. For cell killing, neoplastic transformation, and mutagenesis, the critical biological target for radiation is presumed to be DNA. Our approach to biological microdosimetry does not require detailed information about the mass, volume, and shape of the critical biological target. Further, one does not have to know what formal distribution function applies to the microdose distribution. However, formal distributions are required for the biological data used to derive the non-parametric microdose distributions. Here, we use the binomial distribution to characterise the variability in the number of cells affected by a fixed macroscopic dose. Assuming this variability to arise from variability in the microscopic dose to the critical biological target, a non-parametric microdose distribution is generated by the standard Monte Carlo method. The non-parametric distribution is then fitted using a set of formal distributions (beta, exponential, extreme value, gamma, logistic, log-normal, normal, Pareto, triangular, uniform, and Weibull). The best fit is then evaluated based on statistical criteria (chi-square test). To demonstrate the application of biological microdosimetry, the standard Monte Carlo method is used with radiobiological data for

  5. Introducing Biological Microdosimetry for Ionising Radiation

    Scott, B.R.; Schoellnberger, H

    2000-07-01

    Microdosimetry is important for radiation protection, for understanding mechanisms of radiation action, and for radiation risk assessment. This article introduces a generic, Monte Carlo based approach to biological microdosimetry for ionising radiation. Our Monte Carlo analyses are carried out with a widely used Crystal Ball software. The approach to biological microdosimetry presented relates to quantal biological effects data (e.g. cell survival, mutagenesis, neoplastic transformation) for which there is an initial linear segment to the dose-response curve. The macroscopic dose data considered were selected such that is could be presumed that the vast majority of cells at risk have radiation dose delivered to their critical target. For cell killing, neoplastic transformation, and mutagenesis, the critical biological target for radiation is presumed to be DNA. Our approach to biological microdosimetry does not require detailed information about the mass, volume, and shape of the critical biological target. Further, one does not have to know what formal distribution function applies to the microdose distribution. However, formal distributions are required for the biological data used to derive the non-parametric microdose distributions. Here, we use the binomial distribution to characterise the variability in the number of cells affected by a fixed macroscopic dose. Assuming this variability to arise from variability in the microscopic dose to the critical biological target, a non-parametric microdose distribution is generated by the standard Monte Carlo method. The non-parametric distribution is then fitted using a set of formal distributions (beta, exponential, extreme value, gamma, logistic, log-normal, normal, Pareto, triangular, uniform, and Weibull). The best fit is then evaluated based on statistical criteria (chi-square test). To demonstrate the application of biological microdosimetry, the standard Monte Carlo method is used with radiobiological data for

  6. Nanoscale photoelectron ionisation detector based on lanthanum hexaboride

    Zimmer, C.M.; Kunze, U.; Schubert, J.; Hamann, S.; Doll, T.

    2011-01-01

    A nanoscale ioniser is presented exceeding the limitation of conventional photoionisation detectors. It employs accelerated photoelectrons that allow obtaining molecule specificity by the tuning of ionisation energies. The material lanthanum hexaboride (LaB 6 ) is used as air stable photo cathode. Thin films of that material deposited by pulsed laser deposition (PLD) show quantum efficiency (QE) in the range of 10 -5 which is comparable to laser photo stimulation results. A careful treatment of the material yields reasonable low work functions even after surface reoxidation which opens up the possibility of using ultraviolet light emitting diodes (UV LEDs) in replacement of discharge lamps. Schematic diagram of a photoelectron ionisation detector (PeID) operating by an electron emitter based on the photoelectric effect of lanthanum hexaboride. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Threshold law for positron-atom impact ionisation

    Temkin, A.

    1982-01-01

    The threshold law for ionisation of atoms by positron impact is adduced in analogy with the author's approach to the electron-atom ionisation. It is concluded the Coulomb-dipole region of potential gives the essential part of the interaction in both cases and leads to the same kind of result: a modulated linear law. An additional process which enters positron ionisation is positronium formation in the continuum, but that will not dominate the threshold yield. The result is in sharp contrast to the positron threshold law as recently derived by Klar (J. Phys. B.; 14:4165 (1981)) on the basis of a Wannier-type (Phys. Rev.; 90:817 (1953)) analysis. (author)

  8. Ionisation Chambers for the LHC Beam Loss Detection

    Gschwendtner, E; Dehning, B; Ferioli, G; Kain, V

    2003-01-01

    At the Large Hadron Collider (LHC) a beam loss system will be used to prevent and protect superconducting magnets against coil quenches and coil damages. Since the stored particle beam intensity is 8 orders of magnitude larger than the lowest quench level value particular attention is paid to the design of the secondary particle shower detectors. The foreseen ionisation chambers are optimised in geometry simulating the probable loss distribution along the magnets and convoluting the loss distribution with the secondary particle shower distributions. To reach the appropriate coverage of a particle loss and to determine the quench levels with a relative accuracy of 2 the number of the detectors and their lengths is weighted against the particle intensity density variation. In addition attention is paid to the electrical ionisation chamber signal to minimise the ion tail extension. This optimisation is based on time resolved test measurements in the PS booster. A proposal for a new ionisation chamber will be pre...

  9. Ionisation detectors as monitors of toxic compounds in air

    Leonhardt, J.W.

    1994-01-01

    Beta particles cause ionisation in gas mixtures. The ions produced provide information on the concentration and identity of trace compounds in ambient air. Modern ionisation detectors use ion mobilities to monitor toxic compounds. Chemical solvent, phosphororganic compounds, PCB and many other toxins can be detected using ion mobility detectors (IMD) in the ppb range or lower. Ion mobility detectors have large potential in industry and research because of their sensitivity, specificity, fast response and relatively low cost. Portable devices and fixed installations are possible. The paper discusses the following topics: (1) ionisation sources in IMD: 63 Ni, 3 H, photoionization and corona discharge, (2) basic principles of ion production, (3) ion collection in IMD, (4) design, gas supply, automatic identification and quantification of IMD data, and (5) selected applications. Advantages and problems with this new type of nuclear analytical instrument are also discussed. (author). 2 refs., 9 figs., 3 tabs

  10. Ionised gas kinematics in bipolar H II regions

    Dalgleish, Hannah S.; Longmore, Steven N.; Peters, Thomas; Henshaw, Jonathan D.; Veitch-Michaelis, Joshua L.; Urquhart, James S.

    2018-05-01

    Stellar feedback plays a fundamental role in shaping the evolution of galaxies. Here we explore the use of ionised gas kinematics in young, bipolar H II regions as a probe of early feedback in these star-forming environments. We have undertaken a multi-wavelength study of a young, bipolar H II region in the Galactic disc, G316.81-0.06, which lies at the centre of a massive (˜103 M⊙) infrared-dark cloud filament. It is still accreting molecular gas as well as driving a ˜0.2 pc ionised gas outflow perpendicular to the filament. Intriguingly, we observe a large velocity gradient (47.81 ± 3.21 km s-1 pc-1) across the ionised gas in a direction perpendicular to the outflow. This kinematic signature of the ionised gas shows a reasonable correspondence with the simulations of young H II regions. Based on a qualitative comparison between our observations and these simulations, we put forward a possible explanation for the velocity gradients observed in G316.81-0.06. If the velocity gradient perpendicular to the outflow is caused by rotation of the ionised gas, then we infer that this rotation is a direct result of the initial net angular momentum in the natal molecular cloud. If this explanation is correct, this kinematic signature should be common in other young (bipolar) H II regions. We suggest that further quantitative analysis of the ionised gas kinematics of young H II regions, combined with additional simulations, should improve our understanding of feedback at these early stages.

  11. Use of alpha-radiation for the industrial measurement of surface weight; Utilisation du rayonnement alpha pour les mesures industrielles de poids superficiel; Primenenie al'fa-oblucheniya dlya promyshlennogo izmereniya vesa naruzhnogo pokrova; Empleo industrial de los rayos alfa para la medicion de pesos por unidad de superficie

    Perette, J; Maugest, J [Compagnie d' Applications et Recherches Atomiques, Saint-Denis (France)

    1962-01-15

    The possibility of using alpha-radiation for industrial measurement of the surface weight of thin materials has been mentioned by several authors. The techniques have been adapted for industrial use thanks to research on new equipment which, while employing standard techniques, was specially designed for alpha-radiation. To compensate for variations in the absorbent capacity of the source-detector interval, a two-path differential method must be used. By alternate feeding of the ionization chambers, alternate amplification and detection circuits can be used without prior conversion of the ionization current. The measurement range is 6 to 55 g/m{sup 2} and measurement is accurate to 1% in conditions of perfect stability. The complete equipment used for continuous measurement on production machines is described. The technique can also be used with beta-radiation. (author) [French] Les possibilites d'emploi du rayonnement alpha pour les mesures industrielles de poids superficiel de materiaux minces ont deja ete citees par plusieurs auteurs. L'exploitation industrielle de ces techniques a pu se developper grace a l'etude de nouveaux appareils qui, bien qu'utilisant des techniques classiques, ont ete specialement concus pour l'utili sation du rayonnement alpha. L'emploi d'une methode differentielle a deux trajets est indispensable pour la compensation des variations de pouvoir absorbant de l'intervalle source-detecteur. L'alimentation en alternatif des chambres d'ionisation permet l'utilisation de circuits alternatifs d'amplification et de detection sans conversion prealable du courant d'ionisation. La gamme de mesure s'etend de 6 g a 55 g/m{sup 2} avec line precision de 1% dans des conditions de parfaite stabilite. On decrit le dispositif complet utilise pour les mesures en continu sur les machines de production. Cette technique est egalement utilisable pour les rayonnements beta. (author) [Spanish] Diversos investigadores ya han mencionado la posibilidad de emplear

  12. Quantum coherence in photo-ionisation with tailored XUV pulses

    Carlström, Stefanos; Mauritsson, Johan; Schafer, Kenneth J.; L'Huillier, Anne; Gisselbrecht, Mathieu

    2018-01-01

    Ionisation with ultrashort pulses in the extreme ultraviolet (XUV) regime can be used to prepare an ion in a superposition of spin-orbit substates. In this work, we study the coherence properties of such a superposition, created by ionising xenon atoms using two phase-locked XUV pulses at different frequencies. In general, if the duration of the driving pulse exceeds the quantum beat period, dephasing will occur. If however, the frequency difference of the two pulses matches the spin-orbit splitting, the coherence can be efficiently increased and dephasing does not occur.

  13. Radioactivity; La radioactivite

    NONE

    2002-07-01

    This pedagogical document presents the origin, effects and uses of radioactivity: where does radioactivity comes from, effects on the body, measurement, protection against radiations, uses in the medical field, in the electric power industry, in the food (ionization, radio-mutagenesis, irradiations) and other industries (radiography, gauges, detectors, irradiations, tracers), and in research activities (dating, preservation of cultural objects). The document ends with some examples of irradiation levels (examples of natural radioactivity, distribution of the various sources of exposure in France). (J.S.)

  14. Sensitivity and rapidity of the evaporation method for the measurement of the radioactivity of residual water; Sensibilite et rapidite de la methode d'evaporation pour la mesure de la radioactivite d'une eau residuaire

    Cohen, P; Reiffsteck, A; Wormser, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    The authors have used the evaporation method for counting the radioactivity of water polluted to the tolerance limit by Sr{sup 90}. Total duration of the manipulation is 2 hours. (author) [French] Les auteurs ont utilise la methode d'evaporation pour le comptage de la radioactivite d'une eau polluee, a la limite de tolerance, par du {sup 90}Sr. La duree de la manipulation totale est de 2 h. (auteur)

  15. The case against protecting the environment from ionising radiation

    Smith, J.T.

    2004-01-01

    The objective of this paper is to present the (rarely heard) argument in favour of retention of the present system of radiation protection of the environment. There has been a recent trend in the radioecological and radiation protection community towards greater regulation of the effects of ionising radiations on biota. In particular, the often quoted International Commission on Radiation Protection (ICRP) hypothesis that: If humans are protected from the effects of ionising radiation, then flora and fauna are also adequately protected has been criticised as being too anthropocentric and not adequate for protection of the environment. In this paper I will challenge this view, arguing firstly that this statement is almost always quoted out of its proper context, and secondly that the ICRP hypothesis does adequately protect the environment from the effects of ionising radiations. In view of the relatively insignificant effect of regulated releases of ionising radiation on the environment, the economic cost of further regulation will not result in a significant environmental benefit. Whilst empirical research to test the ICRP hypothesis should continue, until there is clear evidence against it, this simple and cost-effective approach should be retained. This would benefit the environment by directing scarce resources to more urgent environmental problems. (author)

  16. Cost considerations for an ionising energy treatment facility

    Culpitt, R.A.

    1985-01-01

    Variables influencing the cost of food irradiation can be included under three broad headings: the physical characteristics of products to be treated; the operational characteristics of the plant to be used; costs of establishment and operation of an ionising energy treatment

  17. NDT using ionising radiation in the Indian space programme

    Viswanathan, K.

    1997-01-01

    Ionising radiations continue to play a vital role in the Non-Destructive Evaluation (NDE) of various components used in space vehicles and satellites. The different Non-Destructive Testing (NDT) methods which are useful to the Indian space programme are discussed. 4 refs., 5 figs

  18. Studies of the electron-impact double-ionisation process in magnesium using coincidence techniques

    Ford, M.J.

    1998-01-01

    This article will review recent measurements of the electron-impact double-ionisation of atomic magnesium. Results for the resonant Auger double-ionisation process with coincident detection of all three outgoing electrons, the (e, 3e) experiment, and for the direct double-ionisation process where only two outgoing electrons are detected, the (e, (3 -1)e) experiment, will be discussed. The results are analysed with reference to ionisation mechanisms and comparisons are made with calculated double-ionisation cross sections. Copyright (1998) CSIRO Australia

  19. Extra holiday because of ionising radiation not necessary

    Anon.

    1978-01-01

    The 'regulations for special measures to protect employees working with X-rays and radium radiation' of 21st November 1947, which included a statutory six-week holiday period annually, has now been superceded by 'regulations on special protective measures for work with ionising radiation', issued by the Directorate for Work Inspection on 31st March 1978, effective from 1st May 1978. In addition to removing the requirement for six weeks annual holiday for radiation personnel, routine medical surveillance is only required every third year instead of annually. A number of other changes are mentioned. The basis for these changes is that continuous personnel dosimetry and better knowledge of the effects of ionising radiation allows any necessary measures to be taken on the basis of these. (JIW)

  20. {alpha} Spectroscopy by the method of grid ionization grid chamber, application to the case of uranium; Spectrographie {alpha} par la methode de la chambre d'ionisation a grille application a l'uranium

    Sayag, G J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1951-06-15

    Le present work had for aim the verification of the operating of an equipment: chamber of grid ionization, amplifiers and discriminator with nine channels, constructed by the, Commissariat a l'energie Atomique to serve for the {alpha} spectroscopy. To this occasion, different measurements had been done on a source of uranium: energy of the {alpha} of U{sub 234} and U{sub 235} according to those of them {alpha} of U{sub 238} taken as standard, relative intensities, of the {alpha} radiation of the three isotopes and notably of the low abundant group due to the isotope 235. (author) [French] Le present travail a eu pour objet la verification du fonctionnement d'un appareillage: chambre d'ionisation a grille, amplificateurs et discriminateur a neuf canaux, construit par le Commissariat a l'Energie Atomique pour servir a la spectroscopie {alpha}. A cette occasion, differentes mesures ont ete effectuees sur une source d'uranium: energie des {alpha} de U{sub 234} et de U{sub 235} en fonction de celle des {alpha} de U{sub 238} prise pour etalon, intensites relatives des rayonnement {alpha} des trois isotopes et notamment du groupe peu abondant du a l'isotope 235. (auteur)

  1. Medical use of ionising radiation - challenges for the third millennium

    Leitz, W.

    2003-01-01

    From the very beginning after its discovery ionising radiation has been in beneficial use for health care. But even the drawbacks showed up very early: only a few months after Roentgens discovery reports were published on patients who got severe skin damage after fluoroscopy with x-rays. This finding of the adverse effects was soon turned into something positive: ionising radiation could be used for treatment of cancer. In 1928 radiologists took the initiative to the foundation of what later became the International Commission on Radiological Protection, ICRP. Medical use of ionising radiation is giving by far the largest contribution to the radiation burden of the global population from artificial sources, on average 0,3 mSv per year and inhabitant, excluding doses from radiation treatment. In the Nordic countries this dose is approximately 0,7 mSv. This isn't a problem by itself. The total benefit is exceeding the total radiation risk with large margins. But the margins could even be larger. Methods for examinations and treatments have often a potential for improvements, meaning that the medical effect can be obtained with a lower dose to the patient. In certain circumstances the examination does not contribute to the further treatment of the patient or to her/his well-being and is then regarded as not justified. The huge challenge we are facing depends among other things on the extreme fast technical development which enables exposures of a magnitude that we haven't seen before and applications we only could dream about. There is a risk that the motto 'do what is possible to do' is followed instead of 'do what the individual patient needs'. This presentation addresses the possibilities, but also the dangers that medical use of ionising radiation in medical care is facing in the new millennium, or at least in its first years. (orig.)

  2. Basic radiation chemistry for the ionising energy treatment of food

    Moore, P.W.

    1985-01-01

    Before we can understand the chemistry involved in the irradiation of complex substances such as food we need to have some appreciation of the reactions involved and the products formed when ionising energy interacts with the simple substances such as water and dilute solutions. Reactions involving hydrated electrons, hydrogen atoms and hydroxyl radicals are examined and methods for minimising radiolytic effects in foods are discussed

  3. Two-dimensional readout in a liquid xenon ionisation chamber

    Solovov, V; Ferreira-Marques, R; Lopes, M I; Pereira, A; Policarpo, Armando

    2002-01-01

    A two-dimensional readout with metal strips deposited on both sides of a glass plate is investigated aiming to assess the possibility of its use in a liquid xenon ionisation chamber for positron emission tomography. Here, we present results obtained with an alpha-source. It is shown that position resolution of <=1 mm, fwhm, can be achieved for free charge depositions equivalent to those due to gamma-rays with energy from 220 down to 110 keV.

  4. Conversion of electromagnetic waves at the ionisation front

    Chegotov, M V

    2001-01-01

    It is shown that a weak electromagnetic pulse interacting with a copropagating ionisation front is converted in the general case into three electromagnetic pulses with higher and lower frequencies, which propagate in different directions. The coefficients of conversion to these pulses (for intensities) were found as functions of the frequency. The electromagnetic energy is shown to decrease during this conversion because of the losses for the residual electron energy. (interaction of laser radiation with matter. laser plasma)

  5. Fully kinetic simulations of magnetic reconnection in partially ionised gases

    Innocenti, M. E.; Jiang, W.; Lapenta, G.; Markidis, S.

    2016-12-01

    Magnetic reconnection has been explored for decades as a way to convert magnetic energy into kinetic energy and heat and to accelerate particles in environments as different as the solar surface, planetary magnetospheres, the solar wind, accretion disks, laboratory plasmas. When studying reconnection via simulations, it is usually assumed that the plasma is fully ionised, as it is indeed the case in many of the above-mentioned cases. There are, however, exceptions, the most notable being the lower solar atmosphere. Small ionisation fractions are registered also in the warm neutral interstellar medium, in dense interstellar clouds, in protostellar and protoplanetary accreditation disks, in tokamak edge plasmas and in ad-hoc laboratory experiments [1]. We study here how magnetic reconnection is modified by the presence of a neutral background, i.e. when the majority of the gas is not ionised. The ionised plasma is simulated with the fully kinetic Particle-In-Cell (PIC) code iPic3D [2]. Collisions with the neutral background are introduced via a Monte Carlo plug-in. The standard Monte Carlo procedure [3] is employed to account for elastic, excitation and ionization electron-neutral collisions, as well as for elastic scattering and charge exchange ion-neutral collisions. Collisions with the background introduce resistivity in an otherwise collisionless plasma and modifications of the particle distribution functions: particles (and ions at a faster rate) tend to thermalise to the background. To pinpoint the consequences of this, we compare reconnection simulations with and without background. References [1] E E Lawrence et al. Physical review letters, 110(1):015001, 2013. [2] S Markidis et al. Mathematics and Computers in Simulation, 80(7):1509-1519, 2010. [3] K Nanbu. IEEE Transactions on plasma science, 28(3):971-990, 2000.

  6. Ionising radiation safety training in the Australian Defence Organisation (ADO)

    Jenks, G.J.; O'Donovan, E.J.B.; Wood, W.B.

    1998-01-01

    Training personnel in ionising radiation safety within the Australian Defence Organisation (ADO) requires addressing some unique features of an organisation employing both military and civilian personnel. Activities may include those of a civil nature (such as industrial and medical radiography), specific military requirements (for training and emergency response) and scientific research and development. Some personnel may be assigned to full-time duties associated with radiation. However, most are designated as radiation protection officers as a secondary duty. A further complication is that most military personnel are subjected to postings at regular intervals. The ADO's Directorate of Defence Occupational Health and Safety has established an Ionising Radiation Safety Subcommittee to monitor not only the adequacy of the internal Ionising Radiation Safety Manual but also the training requirements. A Training Course, responding to these requirements, has been developed to emphasize, basic radiation theory and protection, operation of radiation monitors available in the ADO, an understanding of the Ionising Radiation Safety Manual, day-to-day radiation safety in units and establishments, and appropriate responses to radiation accidents and emergencies. In addition, students are briefed on a limited number of peripheral topics and participate in some site visits. Currently, two Courses are held annually, each with about twenty students. Most of the material is presented by ADO personnel with external contractor support. The three Courses held to date have proved successful, both for the students and the ADO generally. To seek national accreditation of the course through the Australian National Training Authority, as a first step, competency standards have been proposed. (authors)

  7. Erich Regener and the ionisation maximum of the atmosphere

    Carlson, P.; Watson, A. A.

    2014-12-01

    In the 1930s the German physicist Erich Regener (1881-1955) did important work on the measurement of the rate of production of ionisation deep under water and in the atmosphere. Along with one of his students, Georg Pfotzer, he discovered the altitude at which the production of ionisation in the atmosphere reaches a maximum, often, but misleadingly, called the Pfotzer maximum. Regener was one of the first to estimate the energy density of cosmic rays, an estimate that was used by Baade and Zwicky to bolster their postulate that supernovae might be their source. Yet Regener's name is less recognised by present-day cosmic ray physicists than it should be, largely because in 1937 he was forced to take early retirement by the National Socialists as his wife had Jewish ancestors. In this paper we briefly review his work on cosmic rays and recommend an alternative naming of the ionisation maximum. The influence that Regener had on the field through his son, his son-in-law, his grandsons and his students, and through his links with Rutherford's group in Cambridge, is discussed in an appendix. Regener was nominated for the Nobel Prize in Physics by Schrödinger in 1938. He died in 1955 at the age of 73.

  8. IRID: specifications for the Ionising Radiations Incident Database

    Thomas, G.O.; Croft, J.R.; Williams, M.K.; McHugh, J.O.

    1996-01-01

    Technologies that make use of ionising radiations are widespread. They provide many benefits but, as with other technologies, the use of ionising radiations carries with it the potential for incidents and accidents. Their severity can vary from the trivial to the fatal and may involve substantial economic penalties. In order to minimise the number of incidents and their consequences it is important that there is a mechanism to learn the lessons from those that do occur. To help pursue this objective the National Radiological Protection Board, the Health and Safety Executive and the Environment Agency have established a national Ionising Radiations Incident Database (IRID) to cover radiation incidents in industry, medicine, research and teaching. This publication details the specifications for IRID and its methods of operation. All information in the database will be unattributable and names of persons or organisations will not be included. It is a personal computer based system with 24 fields to categorise an incident, including a text field that will provide a description of the incident giving the causes, consequences, follow-up actions and lessons to be learned. These descriptions will be used in subsequent publications to provide feedback to the users. (UK)

  9. Complex systems of biological interest stability under ionising radiations

    Maclot, Sylvain

    2014-01-01

    This PhD work presents the study of stability of molecular systems of biological interest in the gas phase after interaction with ionising radiations. The use of ionising radiation can probe the physical chemistry of complex systems at the molecular scale and thus consider their intrinsic properties. Beyond the fundamental aspect, this work is part of the overall understanding of radiation effects on living organisms and in particular the use of ionizing radiation in radiotherapy. Specifically, this study focused on the use of low-energy multiply charged ions (tens of keV) provided by the GANIL (Caen), which includes most of the experiments presented. In addition, experiments using VUV photons were also conducted at synchrotron ELETTRA (Trieste, Italy). The bio-molecular systems studied are amino acids and nucleic acid constituents. Using an experimental crossed beams device allows interaction between biomolecules and ionising radiation leads mainly to the ionization and fragmentation of the system. The study of its relaxation dynamics is by time-of-flight mass spectrometry coupled to a coincidences measurements method. It is shown that an approach combining experiment and theory allows a detailed study of the fragmentation dynamics of complex systems. The results indicate that fragmentation is generally governed by the Coulomb repulsion but the intramolecular rearrangements involve specific relaxation mechanisms. (author) [fr

  10. Additives in UV and ionising radiation grafting and curing processes

    Garnett, J.L.; Ng, L.T.; Viengkhou, V.

    1998-01-01

    Full text: Curing of polymers induced by both UV and ionising radiation are now established technologies. Currently both systems are predominantly based on acrylate chemistry. UV processes use photoinitiators to achieve fast polymerisation. In the proposed paper the significance of the occurrence of concurrent grafting with cure will be examined. particularly with respect to the recycling of finished product. Basic studies on grafting initiated by UV and ionising radiation will be discussed. Polar methyl methacrylate (MMA) and non-polar styrene will be used as representative monomers with cellulose and propylene typifying the backbone polymers. The additives chosen for examination in this study are predominantly components used in radiation curing formulations since grafting and curing are known to be mechanically related. The additives used were mineral acid, photoinitiators, vinyl ethers, oligomers, polyfunctional monomers including multifunctional acrylates (MFAs) and methacrylates (MFMAs). For the first time the use of charge transfer complexes in the Mulliken sense as additives in radiation grafting will be discussed. The CT complexes themselves, being monomers, have also been grafted to the above polymers. Recent developments with excimer laser sources for initiating these processes will be discussed, especially the use of non-acrylate chemistry. Excimer laser sources are shown to complement conventional UV and ionising radiation and are photoinitiator free. Mechanisms for the above grafting and curing processes will be outlined

  11. Une méthode pour estimer l’interception du rayonnement par un couvert bas : application au colza avant montaison

    Denoroy Pascal

    2002-01-01

    Full Text Available Dans les modèles de simulation du fonctionnement des cultures, l’interception du rayonnement est une variable cruciale pour la prévision de la productivité en biomasse. D’autre part, la connaissance de l’interception du rayonnement par une culture permet de mieux analyser la réponse à un traitement en autorisant la distinction entre les effets morphogénétique et physiologique du traitement. Par exemple, dans l’étude de la fertilisation azotée du colza [1] on a pu faire la part de l’effet morphogénétique (accroissement de l’indice foliaire, donc de l’interception et de l’amélioration de la conversion photosynthétique du rayonnement absorbé. Dans un cas comme dans l’autre, une estimation correcte de l’interception du rayonnement est essentielle. Très souvent, un formalisme dérivé de la loi de Beer-Lambert est utilisé pour quantifier la part interceptée du rayonnement : PARi = epsiloni PAR (1 et epsiloni = 1 - e- k.IF (2, PAR représentant le rayonnement photosynthétiquement actif incident (exprimé en Joules ou en moles de photons, PARi la part de ce dernier interceptée par le couvert, epsiloni le coefficient (sans dimension d’interception, IF l’indice foliaire et k le coefficient d’extinction du rayonnement. Un formalisme un peu plus complexe doit être utilisé si on veut considérer le rayonnement absorbé [1, 2]. Pour des cultures couvrantes, la sensibilité de ces modèles à la valeur de k est faible pour les IF élevés, c’est pourquoi ces modèles sont souvent utilisés avec succès. Mais aux faibles IF, les modèles sont sensibles à k, d’où l’importance de l’estimation de ce paramètre pour les cultures présentant une longue période de faible couverture du sol, tel le colza peu fertilisé en phase hivernale. De plus, pour les cultures discontinues, c’est-à-dire présentant des zones où le sol n’est pas du tout couvert par la végétation, comme les inter-rangs, on doit

  12. Sensitivity of gaseous xenon ionisation chambers (1961); Sensibilite des chambres d'ionisation a xenon gazeux (1961)

    Schuhl, C [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    It seems advantageous to fill an ionization chamber with xenon gas when this chamber is used for measuring a low intensity and high energy electron or positron beam, or monitoring a gamma beam. In the study of 5 to 50 MeV electrons, xenon allows for the ionization chamber yield, an improvement of a factor 4,5. (author) [French] Il apparait interessant d'utiliser du xenon comme gaz dans une chambre d'ionisation destinee a mesurer un faisceau d'electrons ou de positons de faible intensite et de grande energie ou pour monitorer un faisceau de gamma. Dans les etudes des electrons de 5 a 50 MeV, le xenon permet de gagner un facteur 4,5 sur l'air pour la sensibilite d'une chambre d'ionisation. (auteur)

  13. Semiclassical calculation of ionisation rate for Rydberg helium atoms in an electric field

    Wang De-Hua

    2011-01-01

    The ionisation of Rydberg helium atoms in an electric field above the classical ionisation threshold has been examined using the semiclassical method, with particular emphasis on discussing the influence of the core scattering on the escape dynamics of electrons. The results show that the Rydberg helium atoms ionise by emitting a train of electron pulses. Unlike the case of the ionisation of Rydberg hydrogen atom in parallel electric and magnetic fields, where the pulses of the electron are caused by the external magnetic field, the pulse trains for Rydberg helium atoms are created through core scattering. Each peak in the ionisation rate corresponds to the contribution of one core-scattered combination trajectory. This fact further illustrates that the ionic core scattering leads to the chaotic property of the Rydberg helium atom in external fields. Our studies provide a simple explanation for the escape dynamics in the ionisation of nonhydrogenic atoms in external fields. (atomic and molecular physics)

  14. Recent trends in utilising ionising radiations for nondestructive evaluation of materials (Preprint No. SP-3)

    Raj, Baldev; Venkatraman, B.

    1988-02-01

    The various NDT techniques based on the use of ionising radiations can be broadly classified into radiography, radiation gaging techniques and analytical techniques. This paper highlights the state of art of these techniques along with their applications. While an effort has been made to cover the major techniques based on ionising radiations, many techniques utilising ionising radiations as xeroradiography, laminography, ionography etc, have not been dealt with due to their restricted applications. (author). 23 refs., 4 figs

  15. Open-air ionisation chambers with walls of soft-tissue equivalent material for measuring photon doses; Chambres d'ionisation d'ambiance a parois en materiau equivalent aux tissus mous pour la mesure des doses absorbees dues aux photons

    Vialettes, H.; Anceau, J.C.; Grand, M.; Petit, G. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1968-07-01

    The ionisation chambers presented in this report constitute a contribution to research into methods of carrying out correct determinations in the field of health physics. The use of a mixture of teflon containing 42.5 per cent by weight of carbon for the chamber walls makes it possible to measure directly the dose absorbed in air through 300 mg/cm{sup 2} of soft tissue and, consequently, the dose absorbed in the soft tissues with a maximum error of 10 per cent for photon energies of between 10 keV and 10 MeV. Furthermore since this material does not contain hydrogen, the chamber has a sensitivity to neutrons which is much less than other chambers in current use. Finally the shape of these chambers has been studied with a view to obtaining a satisfactory measurement from the isotropy point of view; for example for gamma radiation of 27 keV, the 3 litre chamber is isotropic to within 10 per cent over 270 degrees, and the 12 litre chamber is isotropic to within 10 per cent over 300 degrees; for 1.25 MeV gamma radiation this range is extended over 330 degrees for the 3 litre chamber, and 360 degrees for the 12 litre chamber. This report presents the measurements carried out with these chambers as well as the results obtained. These results are then compared to those obtained with other chambers currently used in the field of health physics. (authors) [French] Les chambres d'ionisation presentees dans ce rapport apportent une contribution a la recherche de moyens dosimetriques adaptes aux mesures a effectuer pour assurer une dosimetrie correcte dans le domaine de la radioprotection. L'utilisation d'un melange de teflon charge a 42.5 pour cent en masse de carbone comme materiau constituant les parois de la chambre permet de realiser un dosimetre mesurant directement la dose absorbee dans l'air sous 3OO mg/cm{sup 2} de tissu mou et, par consequent, la dose absorbee dans les tissus mous avec une erreur maximale de 10 pour cent, pour des photons d

  16. Experimental studies on the X-radiation from a high-intensity annular discharge; Etudes experimentales sur le rayonnement X d'une decharge annulaire a forte intensite

    Etievant, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    Under certain conditions, a very penetrating X-radiation is emitted at the start of a stabilised annular discharge. A number of experimental observations have been made using a pyrex toroid filled with deuterium or argon. The value of the stabilising magnetic field and the pressure have a very important influence on the intensity of the X-radiation emitted. The placing of an obstacle such as a magnetic mirror at a point of the torus can prevent the acceleration of runaway electrons during successive revolutions, and X-ray emission disappears. (author) [French] Un rayonnement X tres penetrant est emis dans certaines conditions au debut d'une decharge annulaire stabilisee. Un certain nombre d'observations experimentales ont ete faites a l'aide d'un tore en pyrex rempli de deuterium ou d'argon. La valeur du champ magnetique stabilisateur et la pression jouent un role tres important sur l'intensite du rayonnement X emis. La disposition d'un obstacle tel qu'un miroir magnetique en un point du tore peut empecher l'acceleration d'electrons decouples au cours de revolutions successives et l'emission de rayonnement X disparait. (auteur)

  17. Dosimetry techniques of thermal neutrons and {gamma} radiation in reactor cores; Techniques de dosimetrie des neutrons thermiques et du rayonnement {gamma} dans les piles

    Sutton, J; Draganic, I; Hering, H [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1955-07-01

    Chemical studies under radiation done in the reactor cores require to be followed by dosimetry. When the irradiations are done in the reflector, one can limit to the measure of the {gamma} and the neutron radiation. For the dosimetry of the {gamma} radiation, a dosimeter of ferrous sulfate is convenient until doses of about 10{sup 6} rep. The use of aired oxalic acid solutions permits to reach 10{sup 7} rep. The dosimetry of thermal neutrons has been made with solutions of cobalt sulphate or paper filter impregnated with this salt. The total chemical effect of the {gamma} and of the slow neutrons radiation is obtained with solutions of ferrous sulfate added with lithium sulphate. (M.B.) [French] Les etudes de chimie sous radiation faites dans les piles exigent d'etre suivies par dosimetrie. Lorsque les irradiations sont effectues dans le reflecteur, on peut se limiter a doser le rayonnement {gamma} et les neutrons. Pour la dosimetrie du rayonnement {gamma}, un dosimetre a sulfate ferreux convient jusqu'a des doses d'environ 10{sup 6} rep. L'emploi de solutions aerees d'acide oxalique permet d'atteindre 10{sup 7} rep. La dosimetrie des neutrons thermiques a ete faite avec des solutions de sulfate de cotalt ou du papier filtre impregne de ce sel. L'effet chimique total du rayonnement {gamma} et des neutrons lents est obtenu avec des solutions de sulfate ferreux additionne de sulfate de lithium. (M.B.)

  18. Ionised Jets Associated With Massive Young Stellar Objects

    Purser, Simon John Derek

    2017-09-01

    This thesis focuses on the phenomena of ionised jets associated with massive young stellar objects. Firstly a study was conducted with the aim to establish a statistical sample of such objects. Radio observations towards a sample of 49 MYSOs resulted in the detection of 28 objects classified as ionised jets. The jets’ radio luminosities scaled with their MYSOs’ bolometric luminosities in the same way as for low-mass examples. This infers that the jet launching and collimation mechanisms of high-mass jets are very similar to that in their low-mass counterparts and they are ejected for the last ≤65000 yr of the MYSO phase. Interestingly non-thermal emission was regularly detected towards spatially distinct radio lobes (associated with ˜50% of the jets), suggesting the presence of synchrotron emission and therefore, magnetic fields. With an average spectral index of ¯α=‑0. 55 (indicative of the 1st order Fermi acceleration mechanism) it is concluded these lobes are the result of shocks in the jets’ stream. My second science chapter is a study of radio variability, precession and proper motions towards a subset of objects from the first chapter. Over a two year time period, no significant variability and only one example of proper motion (1800±600 km s‑1) was detected. Precession was found to be commonplace however and if it arises as the result of binary interactions, we infer orbital radii between 30 and 1800 au for the binary companions. Lastly, high-resolution, VLA observations at C and Q-bands were analysed to extend the known sample of MYSOs harbouring ionised jets into the northern hemisphere. Only 3 radio sources were detected possessing jet-like characteristics towards the work’s sub-sample of 8 IRDCs containing 44 mm-cores (in our field of view), highlighting the radio-quiet (≳30μJy) nature of this early phase in massive star formation. Towards the RMS survey derived sample of 48 MYSOs, a total of 38 radio sources with jet

  19. Doubling potential of fibroblasts from different species after ionising radiation

    Macieira-Coelho, A.; Diatloff, C.; Malaise, E.

    1976-01-01

    It is stated that whereas chicken fibroblasts invariably die after a certain number of doublings in vitro, and this fact is never altered by chemical or physical agents, mouse fibroblasts invariably acquire spontaneously an infinite growth potential. In the human species fibroblasts never acquire spontaneously the capacity to divide for ever, although they can become permanent cell lines after treatment with certain viruses. This behaviour of fibroblasts in vitro has been attributed to different nutritional requirements. Experiments are described with human and mouse fibroblasts in which it was found that the response to ionising radiation matches the relative tendencies of the fibroblasts to yield permanent cell lines. Irradiation was commenced during the phase of active proliferation. Human fibroblast cultures irradiated with 100 R stopped dividing earlier than the controls, whereas cultures irradiated with 200, 300 and 500 R had the same lifespan as the control cultures. Cultures irradiated with 400 R showed the longest survival. With mouse fibroblasts the growth curves of the irradiated cells were of the same type as in the controls, but recovery occurred earlier. The results indicated that ionising radiation accelerates a natural phenomenon; in cells with a limited growth potential (chicken) it shortens the lifespan, whereas in cells that can acquire an unlimited growth potential (mouse) it accelerates acquisition of this potential; human fibroblasts showed an intermediate response, since ionising radiation neither established the cultures as with mouse cells nor reduced the number of cells produced as with chicken fibroblasts. Possible explanations for the different behaviour of the species are offered. (U.K.)

  20. Fitness of equipment used for medical exposures to ionising radiation

    1998-01-01

    The advice in this guidance note is aimed at employers in control of equipment used for medical exposures to ionising radiation and ancillary equipment. This includes NHS trusts, health authorities or boards, private hospitals, clinics, surgeries, medical X-ray facilities in industry, dentists and chiropractors. The guidance should also be useful to radiation protection advisers appointed by such employers. The guidance provides advice on the requirements of regulation 33 of the Ionising Radiations Regulations 1985 (IRR85). In particular, it covers: (a) the selection, installation, maintenance, calibration and replacement of equipment to ensure that it is capable of restricting, so far as reasonably practicable, the medical exposure of any person to the extent that this is compatible with the intended diagnostic or therapeutic purpose; (b) recommended procedures for the definitive calibration of radiotherapy treatment; and (c) the need to investigate incidents involving a malfunction or defect in any 'radiation equipment' which result in medical exposures much greater than intended and to notify the Health and Safety Executive (HSE). 'Medical exposure' is defined in IRR85 as exposure of a person to ionising radiation for the purpose of his or her medical or dental examination or treatment which is conducted under the direction of a suitably qualified person and includes any such examination or treatment conducted for the purposes of research. For convenience, people undergoing medical exposure will be referred to as 'patients' in this guidance. Nothing in this publication is intended to indicate whether or not patients should be informed of any incident resulting from malfunction or defect in equipment used for medical exposure and the possible consequences of that exposure. As stated above, this guidance concerns medical exposures much greater than intended and although exposures much lower than intended can also have serious consequences, the incident would not

  1. Ionising radiation safety training in the Australian defence organisation (ADO)

    Jenks, G.J.; O'Donovan, E.J.B.; Wood, W.B.

    1996-01-01

    Full text: Training personnel in ionising radiation safety within the Australian Defence Organisation (ADO) requires addressing some unique features of an organisation employing both military and civilian personnel. Activities may include those of a civil nature (such as industrial and medical radiography), specific military requirements (for training and emergency response) and scientific research and development. Some personnel may be assigned to full-time duties associated with radiation, while others may be designated as radiation protection officers in remote units with few duties to perform in this role. A further complication is that most military personnel are subjected to postings at regular intervals. The ADO's Directorate of Defence Occupational Health and Safety has established an Ionising Radiation Safety Subcommittee to monitor not only the adequacy of the internal Ionising Radiation Safety Manual but also the training requirements. A training course, responding to these requirements, has been developed to emphasise: basic radiation theory and protection; operation of radiation monitors available in the ADO; an understanding of the Safety Manual; day-to-day radiation safety in units and establishments; and appropriate responses to radiation accidents and emergencies. In addition, students are briefed on a limited number of peripheral topics and participate in some site visits. Currently, two Courses are held annually, each with about twenty students. Most of the material is presented by ADO personnel with external contractor support. The three Courses held to date have proved sufficiently successful, both for the students and the ADO generally, to seek national accreditation through the Australian National Training Authority and, as a first step, competency standards have been identified

  2. Beam Dynamics in a Muon Ionisation Cooling Channel

    Rogers, Chris

    2008-01-01

    The Neutrino Factory has been proposed as a facility to provide an intense source of neutrinos suitable for the measurement of neutrino oscillation parameters and a possible CP violating phase to unprecedented precision. In the Neutrino Factory, neutrinos are produced by the decay of a muon beam with 20-50 GeV per muon. Initially, the muon beam occupies a large volume in phase space, which must be reduced before the beam can be accelerated. The proposed method to achieve this is to use a solenoidal ionisation colling channel.

  3. Ionising radiations - an ecological problem of indoor architectural environment

    Djukanovic, M.

    1995-01-01

    Architectural buildings are assessed not only for their esthetic characteristics but human settlements are considered now, as ecosystems and homes and flats as habitats (bio tops). Because of that healthy environment and influences of nonpolluting factors are of a great importance. The use of appropriate building materials harmless to health, contrary to the use of those that emit radon with its ionising effects and consequent health hazards, is of a great importance, too. The purpose of this paper is to emphasize the importance of investigation of building materials before their use, as well as the importance of quality control of soil where the construction is planned. (author)

  4. On analytical fits for electron impact ionisation cross sections

    Godunov, A.L.; Ivanov, P.B.

    1999-01-01

    The problem of providing accurate recommended analytical fits for electron impact ionisation cross sections is discussed, and a number of approaches are considered on the sample case of neon and its ions. The previously known fits are being reassessed using complete experimental and theoretical data, with the preference for experiment, to avoid systematic shifts introduced by the present calculation methods. The feasibility of the standard BELI formula is investigated in detail, and a number of other analytical expressions is suggested, approximating single-ionization cross sections in the whole range of energies. The factors influencing the accuracy of the fits and the physical meaning of the parameters obtained are discussed. (orig.)

  5. The Radman Guide to the Ionising Radiations Regulations 1985

    Hughes, D.

    1986-01-01

    The guidance given in the handbook is of general nature for the assistance of senior managers and administrators (rather than scientific or technical staff), involved in or responsible for work with ionising radiations. The subject is dealt with under the following headings: 1) Digest of the Regulations. 2) Application of Regulations (division of responsibility between employer, employee, supervisors, medical personnel etc., role of the Health and Safety Executive.) 3) Designation of work areas and persons 4) Radiation Protection Supervisors and Local Rules 5) Hazard assessments and contingency plans 6) Notifications and Record Keeping 7) Routines in source control. (UK)

  6. Injuries to embryo and foetus from ionising radiation

    Devik, F.

    1980-01-01

    A brief review is given of experimental and clinical evidence for tetatological effects of ionising radiation, against the background of general teratology. International and national recommendations and regulations for the protection of the conceptus are quoted. As to interruption of a pregnancy following an unintended exposure, it is pointed out that much of the present evidence points to a dose in the order of 0.1Gy (10 rads) as a dose which may be considered as a practical threshold for the induction of congenital defects. (Auth.)

  7. ALARA - the contribution of the proposed new ionising radiations regulations

    Young, T.O.

    1982-01-01

    This paper describes the proposed regulatory requirements and appropriate guidance contained in the approved code of practice on ionising radiations which are designed to support and help reach the objective of keeping radiation doses as low as reasonably achievable. This is discussed against the background of factory legislation, and the way in which the form of the proposed legislation handles this topic is illustrated. The measures required by the proposed legislation are reviewed, both as direct measures designed to create a climate of dose reduction, and as general measures designed to achieve the same end by means of a wide range of requirements. (author)

  8. Thermal ionisation mass spectrometry (TIMS): what, how and why?

    Aggarwal, S.K.

    2002-01-01

    Thermal ionisation mass spectrometry (TIMS) is one of the oldest mass spectrometric techniques, which has been used for determining the isotopic composition and concentration of different elements using isotope dilution. In spite of the introduction of many other inorganic mass spectrometric techniques like spark source mass spectrometry (SSMS), glow discharge mass spectrometry (GDMS), inductively coupled plasma-mass spectrometry (ICP-MS), secondary ion mass spectrometry (SIMS), the TIMS technique plays the role of a definitive analytical methodology and still occupies a unique position in terms of its capabilities with respect to precision and accuracy as well as sensitivity

  9. On the critical current of ionisation waves in gas discharges

    Sato, M.

    1982-01-01

    Measurement methods for determining the critical current of ionisation waves in gas discharge tubes are examined in detail. The conventional visual method which finds the current at which the waves disappear is erroneous since the criterion, 'observable', depends on the observing conditions. In the rigorous method it is defined as a current at which the linear growth rate of waves is zero. For the measured upper critical (Pupp) current of argon gas, close agreement is found between the results of other workers and those of the present author over a wide range of pressure-radius product 0.3 approximately equal to 60 Torr cm. (author)

  10. Use of ionising radiation for food processing applications

    Ninjoor, V.

    1989-01-01

    Food irradiation is a recently developed technique used to sterilize and preserve food. Food products are exposed to ionising radiations such as X-rays, gamma rays or high energy electrons which destroy food borne pathogens and parasites and inhibit sprouting. Shelf life of food is extended. The following aspects of radiation processing of food are discussed in the monograph: radiation sources, choice of dose for specific results, safety and nutritional quality of radiation processed food, international status of acceptance of food irradiation, and cost. (M.G.B.). 6 tabs

  11. The K-shell ionisation of atoms by relativistic protons

    Davidovic, D.M.; Moiseiwitsch, B.L.; Norrington, P.H.

    1978-01-01

    The K-shell ionisation of atoms by protons travelling with relativistic velocities is investigated using an extension of the first-order time-dependent perturbation-theory treatment of Moeller (Ann. Phys. Lpz.; 14:531 (1932)), taking Dirac plane waves for the description of the incident and scattered protons and the Darwin approximation for the relativistic wavefunctions of the K-shell atomic electrons and the ejected electron. The differential cross sections and total cross sections are calculated. Results are compared with those of earlier workers. (author)

  12. The L1-shell ionisation of atoms by relativistic particles

    Moiseiwitsch, B.L.; Norrington, P.H.

    1979-01-01

    An expression for the L 1 -shell ionisation cross sections of atoms by high-energy particles has been derived using the relativistic plane-wave Born approximation. The incident and scattered particles are described by Dirac plane waves while Darwin hydrogenic wavefunctions are used for the atomic electrons. A comparison is made with experimental total cross sections for incident electrons in the energy range 1-2 MeV. The agreement is a considerable improvement on that obtained using the non-relativistic planewave Born approximation. (author)

  13. Setting up and performance of a laser enhanced ionisation spectrometer

    Chandola, L.C.; Khanna, P.P.; Razvi, M.A.N.

    1990-01-01

    A laser enhanced ionisation (LEI) spectrometer has been successfuly set up around an excimer laser pumped dye laser. The performance of the spectrometer has been tested by analysing sodium in water solutions. A straight line working curve has been obtained in the concentration range of 1-1000 ng/ml of Na. The effect of parameters like laser power, ion collector electrode voltage and the load resistance on LEI signals has been investigated. The spectrometer is useful not only for analytical purposes but also for laser spectroscopic studies of species formed in flames, study of phenomenon of combustion etc. (author). 1 tab ., 10 figs., 5 refs

  14. EDDIX--a database of ionisation double differential cross sections.

    MacGibbon, J H; Emerson, S; Liamsuwan, T; Nikjoo, H

    2011-02-01

    The use of Monte Carlo track structure is a choice method in biophysical modelling and calculations. To precisely model 3D and 4D tracks, the cross section for the ionisation by an incoming ion, double differential in the outgoing electron energy and angle, is required. However, the double differential cross section cannot be theoretically modelled over the full range of parameters. To address this issue, a database of all available experimental data has been constructed. Currently, the database of Experimental Double Differential Ionisation Cross sections (EDDIX) contains over 1200 digitalised experimentally measured datasets from the 1960s to present date, covering all available ion species (hydrogen to uranium) and all available target species. Double differential cross sections are also presented with the aid of an eight parameter functions fitted to the cross sections. The parameters include projectile species and charge, target nuclear charge and atomic mass, projectile atomic mass and energy, electron energy and deflection angle. It is planned to freely distribute EDDIX and make it available to the radiation research community for use in the analytical and numerical modelling of track structure.

  15. Biological monitors for low levels of ionising radiation

    Mohankumar, M.N.; Jeevanram, R.K.

    1995-01-01

    The biological effects of high doses of ionising radiation are well understood and the methods of measurement of these doses well established. However the effects due to extremely low doses remain by and large uncertain. This is because of the fact that at such low doses no gross symptoms are seen. In fact, at these levels the occurrence of double strand breaks leading to the formation of chromosomal aberrations like dicentrics is rare and chances of mutation due to base damage are negligible. Hence neither chromosomal aberration studies nor mutational assays are useful for detecting doses of the order of a few milligray. Results of exhaustive work done by various laboratories indicate that below 20 mGy the chromosomal aberration technique based on scoring of dicentrics cannot distinguish between a linear or a threshold model. However indirect methods like unscheduled DNA synthesis (UDS) and sister chromatid exchanges (SCEs) appear to be promising for the detection of radiation exposures due to low levels of radiation. This report reviews the available literature on the biological effects of low levels of ionising radiation and highlights the merits and demerits of the various methods employed in the measurement of UDS and SCE. The phenomenon of radio-adaptive response (RAR) and its relation to DNA repair is also discussed. (author)

  16. Electron impact ionisation cross-sections of 2-heptanone

    Vacher, J. R.; Blin-Simiand, N.; Jorand, F.; Pasquiers, S.

    2005-01-01

    The electron impact ionisation of 2-heptanone between 13 and 78 eV is studied using mass spectrometry. CH3C(O)CH2CH2CH2CH2CH3+ and fragment ions are produced with a total cross-section of 5 × 10-16 cm2 towards 50 eV. Two ions, identified as CH3CO+ (43 amu) and CH3C(OH)CH2+ (58 amu), contribute to about 60% of the total cross-section for electron energies above the ionisation threshold. The detected ions are identified using ab initio calculations. For E = 14 eV, the ion of 58 amu is the most abundant followed by an ion of 59 amu identified as being CH3C(OH)CH3+; they result from a bond cleavage with one or two H atom rearrangements. For E >= 48 eV, the ion of 43 amu is the most abundant; it results from an [alpha]-cleavage reaction in the molecular ion.

  17. Electron impact ionisation cross sections of iron oxides

    Huber, Stefan E.; Mauracher, Andreas; Sukuba, Ivan; Urban, Jan; Maihom, Thana; Probst, Michael

    2017-12-01

    We report electron impact ionisation cross sections (EICSs) of iron oxide molecules, FexOx and FexOx+1 with x = 1, 2, 3, from the ionisation threshold to 10 keV, obtained with the Deutsch-Märk (DM) and binary-encounter-Bethe (BEB) methods. The maxima of the EICSs range from 3.10 to 9 . 96 × 10-16 cm2 located at 59-72 eV and 5.06 to 14.32 × 10-16 cm2 located at 85-108 eV for the DM and BEB approaches, respectively. The orbital and kinetic energies required for the BEB method are obtained by employing effective core potentials for the inner core electrons in the quantum chemical calculations. The BEB cross sections are 1.4-1.7 times larger than the DM cross sections which can be related to the decreasing population of the Fe 4s orbitals upon addition of oxygen atoms, together with the different methodological foundations of the two methods. Both the DM and BEB cross sections can be fitted excellently to a simple analytical expression used in modelling and simulation codes employed in the framework of nuclear fusion research. Supplementary material in the form of one pdf file available from the Journal web page at http://https://doi.org/10.1140/epjd/e2017-80308-2.

  18. Biological monitors for low levels of ionising radiation

    Mohankumar, M N; Jeevanram, R K [Safety Research and Health Physics Group, Indira Gandhi Centre for Atomic Research, Kalpakkam (India)

    1996-12-31

    The biological effects of high doses of ionising radiation are well understood and the methods of measurement of these doses well established. However the effects due to extremely low doses remain by and large uncertain. This is because of the fact that at such low doses no gross symptoms are seen. In fact, at these levels the occurrence of double strand breaks leading to the formation of chromosomal aberrations like dicentrics is rare and chances of mutation due to base damage are negligible. Hence neither chromosomal aberration studies nor mutational assays are useful for detecting doses of the order of a few milligray. Results of exhaustive work done by various laboratories indicate that below 20 mGy the chromosomal aberration technique based on scoring of dicentrics cannot distinguish between a linear or a threshold model. However indirect methods like unscheduled DNA synthesis (UDS) and sister chromatid exchanges (SCEs) appear to be promising for the detection of radiation exposures due to low levels of radiation. This report reviews the available literature on the biological effects of low levels of ionising radiation and highlights the merits and demerits of the various methods employed in the measurement of UDS and SCE. The phenomenon of radio-adaptive response (RAR) and its relation to DNA repair is also discussed. (author). 98 refs., 11 figs., 4 tabs.

  19. Investigation of damage mechanism by ionising radiation on biomolecules

    Lau How Mooi

    1996-01-01

    Occupational radiation hazard is a very controversial subject. Effects from high radiation doses are well known from past experiences. However, hazard from low doses is still a subject that is hotly debated upon until now. The occupational dosimetry used now is based on a macroscopic scale. Lately, microdosimetry is fast gaining recognition as a more superior way of measuring hazard. More importantly, scientists are researching the basic damage mechanism that leads to biological effects by ionising radiation. In this report, a simulation study of the basic damage mechanism is discussed . This simulation is based upon Monte Carlo calculations and using polyuridylic acid (Poly-U) as the DNA model This simulation tries to relate the physics and chemistry of interactions of ionising radiation with biomolecules. The computer codes used in this simulation, OREC and RADLYS were created by Hamm et al. (1983) in Oak Ridge National Laboratory. The biological endpoints in this simulation are the strand break and base release of the DNA, which is the precursor of all biological effects. These results are compared with model studies that had been done experimentally to check the validity of this simulation. The G-values of strand break and base release from this simulation were -2.35 and 2.75 and compared well with results from irradiation experiments by von Sonntag (I 98 7) from Max Plank's Institute, Germany

  20. Documentation of Occupational Accidents and Diseases caused by Ionising Radiation

    Fehringer, F.; Seitz, G.

    2004-01-01

    . One of the major goals of the institutions for statutory accident insurance is the prevention of occupational diseases. To perform a successful prevention work it is necessary not only to count the number of accidents or diseases in the various working fields but to look for details of the conditions of work and the human response to those conditions. The institutions for statutory accident insurance have engaged the institution for statutory accident insurance in the precision engineering and electrical industry to carry out documentation, in form of a data bank, for all cases of occupational diseases which could be caused by ionising radiation. Those are not only the cases which are accepted as occupational disease but also the cases where a suspicion of an occupational disease is announced but finally rejected. At the moment about 1700 cases are included in the data bank. For preserving the anonymity information to name and residence are deleted. Various data to one single case are linked by a case-specific key-number. Information to occupation and field of working, to details of a possible exposure to ionising radiation like kind of radiation, time and duration of radiation, exposure of the whole body or of parts of the body and whole body or organ doses are collected. Additional information refers to medical aspects like diagnosis and date of diagnosis. (Author)

  1. Characterisation of bacteria by matrix-assisted laser desorption/ionisation and electrospray mass spectrometry

    Baar, B.L.M. van

    2000-01-01

    Chemical analysis for the characterisation of micro-organisms is rapidly evolving, after the recent advent of new ionisation methods in mass spectrometry (MS): electrospray (ES) and matrix-assisted laser desorption/ionisation (MALDI). These methods allow quick characterisation of micro-organisms,

  2. Use of voltammetry for in vitro equilibrium and transport studies of ionisable drugs

    Matej Velicky

    2014-09-01

    Full Text Available In this review, we will briefly outline the voltammetric investigations of the transfer of ionisable drugs at the interface between two immiscible electrolyte solutions. The voltammetric techniques enable the determination of some key in vitro properties of ionisable drugs, including partition coefficient, diffusion coefficient and membrane permeability. Some successful applications will be highlighted, together with the background methodologies.

  3. Application of R-Matrix with Time-dependence Theory to Double Ionisation Using a 2-electron Outer Region

    Wragg, Jack; Parker, J S; Van der Hart, H W

    2015-01-01

    R-Matrix with Time-dependence (RMT) theory has been extended to cover double-ionisation processes. An application to photoionisation of He is demonstrated, with an emphasis on double-ionisation cross sections. (paper)

  4. Electron spectroscopy of He and NO using electron impact and multiphoton ionisation

    Kimman, J.T.N.

    1984-01-01

    This thesis describes two experimental studies which are intended to contribute to our knowledge of the structure of molecules and the decay dynamics of excited molecular states. The two studies have in common that they are both concerned with ionisation processes, in which an accurately known amount of energy is transferred to the target, and energy analysis of the ejected electrons is made. Ionisation is caused either by scattering electrons off the molecules (chapter 2: electron impact ionisation) or by a simultaneous absorption of several photons (chapter 3: multiphoton ionisation). In chapter 2 an electron impact ionisation experiment on Helium is described in which the kinematics of both the scattered and the ejected electrons is fully determined ((e,2e) experiment). (Auth.)

  5. The use of detectors based on ionisation recombination in radiation protection

    Sullivan, A.H.

    1984-01-01

    Intitial recombination of ionisation in a gas depends on the ionisation density and hence on the linear energy transfer along the tracks of charged particles. This effect can be used as a basis for instruments that respond to different types of ionising radiation approximately in the way required by the quality factor-linear energy transfer relation recommended by the ICRP for use in radiation protection. Empirical instruments based on ionisation recombination that have been used for radiation protection measurements are reviewed, and relations are derived from recombination theory that show that the response of such detectors can be readily predicted. The usefulness of recombination instruments in radiation protection is discussed and their advantages and limitations assessed. It is shown that their main application will be as reference instruments against which other detectors can be calibrated. As an extension to using recombination detectors as reference instruments, the feasibility of specifying radiation quality in terms of ionisation recombination is investigated. (author)

  6. Radioactive Metrology Methods in the USSR; Methodes de metrologie de la radioactivite en URSS; Metody metrologii radioaktivnosti v SSSR; Metodos de Metrologia de la Radiactividad Aplicados en la Union de Republicas Socialistas Sovieticas

    Aglintsev, K K; Bochkarev, V V; Grablevskij, V N; Karavaev, F M

    1960-06-15

    radioactivite (curie, equivalent-gramm e de Ra, roentgen, rad). En ce qui concerne les radionuclides, les sources etalons couramment produites en URSS sont de deux types: 1. Sources modeles servant a l'etalonnage par comparaison d'autres preparations radioactives, ainsi qu'au calibrage d'appareils radiometrique s et de moniteurs de rayonnement; 2. Sources de controle servant exclusivement a la verification du fonctionnement et au controle de la reproductibilite des indications fournies par les appareils de mesure. Les sources a modeles sont preparees par depot electrolytique sur platine d'emetteurs convenablemen t choisis (U naturel, U{sup 233}, Pu{sup 239}, Am{sup 241}). Peuvent etre fournies des activites variant de 30 a 10{sup 6} desintegrations par minute. Les sources a de controle sont constituees par un depot electrolytique de Pu{sup 239} en couche de masse specifique variant de 3.10{sup -9} a 0.7 mg/cm{sup 2}, ce qui corres- pond a des activites allant de 10 jusqu'a 10{sup 8} desintegrations par minute. Les sources {beta} modeles sont constituees de radionuclides choisis de facon a assurer une gamme d'energies limites allant de 0.018 MeV a 2.3 MeV. Les sources {beta} de controle sont faites soit de Sr{sup 90} + Y{sup 90}, soit de Tl{sup 204}, soit enfin de Pm{sup 147}. Ces sources couvrent une large gamme d'activites, entre 20 et 10{sup 9} desintegrations par minute. Les sources {gamma} modeles sont constituees soit de Ra, soit de Co{sup 60}, soit enfin de Cs{sup 137}. La gamme des activites de ces etalons est comprise entre les ordres de grandeur 10{sup -11} et 5 equivalents-gramm e de Ra. Les sources {gamma} de controle sont preparees a partir des memes radionuclides que ci-dessus. Les activites couvrent une gamme tres etendue, les sources ayant des formes et dimensions tres variees. Enfin, les sources modeles de neutrons sont de deux sortes: Ra-{alpha}-Be (contenant de 1 a 1000 mg de Ra) et Pu-{alpha}-Be (contenant de 0.01 a 15 g Pu). Les sources Ra-{alpha}-Be sont

  7. Alteration of the digestive motility linked with radiation-induced inflammatory processes in rats; Alterations de la motricite digestive associees aux processus inflammatoires induits par les rayonnements ionisants chez le rat

    Picard, C

    2000-12-01

    Exposure to ionizing radiation, whether accidental or for medical reasons, may lead to gastro-intestinal injury, characterized by nausea, vomiting, diarrhea and abdominal cramps. The aetiology of radiation-induced diarrhea remains to date unclear. In this study, we have investigated the acute effects of a 10 Gy abdominal irradiation on rat digestive functions. The objective of the first study was to evaluate the role of sensory afferent neurons, capsaicin-sensitive, on morphological changes and the inflammatory response following exposure. Three days after irradiation, we observed an inflammatory response characterized by neutrophils infiltration and mast cells de-granulation. No effect of capsaicin pre-treatment was seen on these parameters. However, neutrophils infiltration was increased as early as one day after irradiation in capsaicin-treated rats. No difference in severity of diarrhea was observed after denervation nor in morphological changes. These data demonstrate that abdominal irradiation results in diarrhea concomitant with an inflammatory response, and that sensory innervation does not play a major protective role. The objective of the rest of the work was in the first instance to characterize radiation-induced alterations of intestinal and colonic motility leading to diarrhea and secondly to evaluate the role of serotonin in such disorders. Perturbations in intestinal (MMC) and colonic (LSB) motor profiles were observed from the first day onwards. Migrating motor complexes (MMC) were completely disrupted at three days at the same time as the onset of diarrhea. In addition to inhibition of LSB, colonic fluid absorptive capacity was decreased and serotonin colonic tissue levels were increased three days after irradiation. Radiation-induced diarrhea was reduced by treatment with an antagonist of 5-HT{sub 3} receptors, granisetron, as were alterations of colonic motility and serotonin tissue levels. However, this treatment did not significantly ameliorate fluid absorption on three days. These two studies show that a 10 Gy abdominal irradiation markedly affects intestinal and colonic motility both of which contribute to the ensuing diarrhea, and a role for serotonin via 5-HT{sub 3} receptors. In conclusion, these results demonstrate functional modifications without marked alterations of intestinal and colonic morphology. These changes are concomitant with an inflammatory response which does not appear to involve afferent nerves. However, serotonin plays an important role in the inhibition of colonic motility and in consequence in the establishment of diarrhea. (author)

  8. Prevention of cancer and the dose-effect relationship: the carcinogenic effects of ionizing radiations; La prevention du cancer et la relation dose-effet: l'effet cancerogene des rayonnements ionisants

    Tubiana, M. [Centre Antoine-Beclere, Faculte de Medecine, 75 - Paris (France)

    2009-07-15

    Cancer prevention has to be based on robust biological and epidemiological data, therefore its reappraisal becomes mandatory in view of recent progress in the understanding of carcinogenesis. The first phase of the carcinogenic process, that of initiation, is generally associated with mutation; however the role of extrinsic mutagens is less critical than was thought two decades ago. During intracellular oxygen metabolism, reactive oxygen species (R.O.S.) are made which are potent mutagens. Defense mechanisms against these intrinsic mutagens include scavenger and enzymatic systems which destroy them (catalase, superoxide dismutase). When the radiation dose is low, DNA repair is very effective as well as the elimination of cells with unrepaired or bad repaired DNA. Therefore a small increase in the number of R.O.S., such as that caused by a small dose of radiation has most probably no significant effect on the risk of DNA damage. These conclusions are consistent with the concept of a practical threshold. The second phase, that of promotion, appears to be the key one. During the promotion phase, initiated cells must acquire new properties (immortalization, release of angiogenic factors, resistance to hypoxia, etc.) in order to become pre-cancerous. This evolution is due to the accumulation in the genome of 6 to 10 new alteration defects. In the clone of initiated cells, the occurrence in one cell of a mutation or an epigenetic event gives birth to a sub clone. There is a Darwinian type competition between the sub clones and those with the more rapid growth because dominant (the acceleration of the growth rate can be due to shorter cell cycles or to an alleviation of cell proliferation exerted by the neighboring cells or the microenvironment). In the dominant sub clones new genomic events provoke the appearance of new sub clones growing more rapidly and having greater autonomy. The process is very slow because the specific genetic events that favour this evolution seldom occur. Promoting factors are agents that either perturb intercellular signalling or stimulate cell proliferation (e.g. hormones) or increase cell mortality: mechanical or chemical irritation (e.g. alcohol, bacteria, viruses) thereby inducing compensatory cell proliferation. Thus, gradually pre-cancerous cells become able to divide more rapidly with greater autonomy. This phase ends when a sub clone of cells has acquired the capacity of autonomous proliferation. The third phase is that of progression during which cells proliferate regularly without any stimulation. In one of the cells of one of the pre-cancerous lesions (e.g. polyps) a cell acquires the capacity of invading surrounding tissue or to metastasize. The whole carcinogenic process is very slow, extending over several decades, because the specific mutations seldom occur and the probability of an accumulation of several specific mutations in the same cell or cell lineage is very small. It can be accelerated by intense stimulation of cell proliferation or genetic instability. Ionizing radiations act firstly as a mutagen, however when the dose is high they also kill a significant proportion of cells and by a homeostatic mechanism they induce cell proliferation and clonal amplification. It has been claimed that even the smallest dose of radiation can induce a cancer. This concept is associated with the L.N.T. model and it is not based on scientific evidence. It has fuelled a fear of radiation which had detrimental consequences. Conversely the high efficacy of defense mechanisms against radio carcinogenesis, particularly when the tissue is not disorganized, can explain the lack of carcinogenic effect of contamination by small doses of radium or thorium which has been observed on radium dial painters or in patients injected with thorotrast. The study of second cancers in patients treated by radiotherapy could provide important information and should be actively pursued with two aims: reduce the incidence of second cancers; to better understand radio carcinogenesis and the relation between dose and carcinogenic effect. (authors)

  9. Ionizing radiation sources: very diversified means, multiple applications and a changing regulatory environment. Conference proceedings; Les sources de rayonnements ionisants: des moyens tres diversifies, des applications multiples et une reglementation en evolution. Recueil des presentations

    NONE

    2011-11-15

    This document brings together the available presentations given at the conference organised by the French society of radiation protection about ionizing radiation source means, applications and regulatory environment. Twenty eight presentations (slides) are compiled in this document and deal with: 1 - Overview of sources - some quantitative data from the national inventory of ionizing radiation sources (Yann Billarand, IRSN); 2 - Overview of sources (Jerome Fradin, ASN); 3 - Regulatory framework (Sylvie Rodde, ASN); 4 - Alternatives to Iridium radiography - the case of pressure devices at the manufacturing stage (Henri Walaszek, Cetim; Bruno Kowalski, Welding Institute); 5 - Dosimetric stakes of medical scanner examinations (Jean-Louis Greffe, Charleroi hospital of Medical University); 6 - The removal of ionic smoke detectors (Bruno Charpentier, ASN); 7 - Joint-activity and reciprocal liabilities - Organisation of labour risk prevention in case of companies joint-activity (Paulo Pinto, DGT); 8 - Consideration of gamma-graphic testing in the organization of a unit outage activities (Jean-Gabriel Leonard, EDF); 9 - Radiological risk control at a closed and independent work field (Stephane Sartelet, Areva); 10 - Incidents and accidents status and typology (Pascale Scanff, IRSN); 11 - Regional overview of radiation protection significant events (Philippe Menechal, ASN); 12 - Incident leading to a tritium contamination in and urban area - consequences and experience feedback (Laurence Fusil, CEA); 13 - Experience feedback - loss of sealing of a calibration source (Philippe Mougnard, Areva); 14 - Blocking incident of a {sup 60}Co source (Bruno Delille, Salvarem); 15 - Triggering of gantry's alarm: status of findings (Philippe Prat, Syctom); 16 - Non-medical electric devices: regulatory changes (Sophie Dagois, IRSN; Jerome Fradin, ASN); 17 - Evaluation of the dose equivalent rate in pulsed fields: method proposed by the IRSN and implementation test (Laurent Donadille, IRSN); 18 - Dosimetry in the environment of a ultra-high intensity laser (Jean-Marie Fauquant, Pascal Monot, CEA); 19 - Use of operational dosemeters in interventional radiology/cardiology: results of the Oramed European project (Isabelle Clairand, IRSN); 20 - Awareness-raising to nuclear materials protection and control among 'small owners' (David Ladsous, IRSN); 21 - Management of spent sealed sources (Bernard Sevestre, CEA); 22 - Preparation and implementation of a withdrawal plan for radioactive Overvoltage arresters (Robert Farejeaux, France Telecom); 23 - Radioactive sources transport Regulation (Gabriel Meyer, ASN); 24 - Status after 3 years of Camari examination (certificate of professional competence in the handling of industrial radiological devices) 2008-2011 (Jean-Pierre Vidal, IRSN) 25 - Approval of cases for the internal transport of calibration sources (Jean-Pierre Marcassoli, Areva); 26 - Use of measurement devices, except radiometers, for the technical and environmental radiation protection controls of sources and devices (Thierry Lahaye, DGT); 27 - Complexity of radiation protection controls of unaccessible sources (Philippe Tranchant, Technam Industrie); 28 - Isemir (Information System on Occupational Exposure in Medicine, Industry and Research) - Report from the working group on industrial radiography (Gonzague Abela, EDF)

  10. Modelling solar radiation interception in row plantation. 3. Application to a traditional vineyard; Modélisation de l’interception des rayonnements solaires dans une culture en rangs. 3. Application à une vigne traditionnelle

    Sinoquet, H. [Institut National de la Recherche Agronomique, Pointe a Pitre (France); Valancogne, C.; Lescure, A.; Bonhomme, R.

    1992-07-01

    A previously described model of solar radiation interception was applied to a spatially discontinuous canopy: that of a traditional vineyard in which the classical terms of the radiative balance and the spatial distribution of the radiation transmitted to the soil were measured. Comparison of measured and simulated data gave satisfactory agreement for reflected radiation (fig 4), but major discrepancies appeared for mean transmitted radiation (fig 5). The use of small stationary sensors for measuring the transmitted radiation explains the latter observation, since most of the time they measured radiation received on the ground in the sunflecks or in the shaded area rather than mean radiation. This was verified by comparing the measured and simulated spatial distribution of transmitted radiation (figs 7, 8). Finally, the influence of the woody parts which were not taken into consideration in the model was clearly identified : it significantly reduced the transmission of incident radiation (fig 9), and to a greater degrees the closer the sensor was to the vegetation row. (author) [French] Un modèle d’interception du rayonnement solaire décrit précédemment est appliqué à un couvert spatialement discontinu : une vigne traditionnelle sur laquelle ont été mesurés les termes classiques du bilan radiatif et la distribution spatiale du rayonnement transmis au sol. La comparaison des mesures au modèle révèle un ajustement satisfaisant pour le rayonnement réfléchi (fig 4), mais assez médiocre pour le rayonnement transmis moyen (fig 5). Ceci est expliqué par l’utilisation de capteurs ponctuels qui, en raison de leur taille, mesurent plus souvent le rayonnement reçu au sol dans les taches de soleil ou les zones d’ombre qu’un rayonnement moyen. Ceci est vérifié en comparant les distributions mesurées et calculées du rayonnement transmis au sol (figs 7 et 8). Enfin, l’influence des parties ligneuses, non prise en compte dans le modèle, est

  11. The activity of {gamma}-emitters as measured by ionisation chambers the determination of the specific emission coefficient {gamma} for some radio-elements (1961); Mesure de l'activite des emetteurs {gamma} par chambre d'ionisation. Determination du coefficient specifique d'emission {gamma} de quelques radioelements (1961)

    Engelmann, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1962-06-15

    chambre d'ionisation gamma, permettant soit de mesurer l'activite de sources radioactives, soit de determiner le coefficient specifique d'emission {gamma} (ou coefficient K) d'un radioelement determine. Les chambres d'ionisation etudiees appartiennent a deux categories: chambre-cavites en graphite, et chambres a puits {gamma}. Pour les mesures effectuees avec une chambre-cavite, on a calcule les differents facteurs do correction dont il faut tenir compte, en particulier les corrections de geometrie et d'hygrometrie. Les corrections d'absorption et d'autoabsorption ont amene a introduire la notion 'd'energie efficace {gamma}' d'un radioelement. Dans le cas des chambres a puits, on a montre qu'une forme appropriee des 'electrodes permettait d'ameliorer leurs performances. Une des chambres decrites permet la mesure des emetteurs {beta} par le rayonnement de freinage associe. Pour la determination du coefficient K de quelques radioelements, il s'est avere commode d'utiliser une chambre a puits a parois de graphite, les mesures etant effectuees par comparaison avec un etalon de radium. La validite de la methode a ete verifiee avec quelques radioelements pour lesquels la valeur du coefficent K etait deja bien connue ({sup 24}Na, {sup 60}Co, {sup 131}I, {sup 198}Au). Pour d'autres radioelements, les valeurs suivantes ont ete obtenues (exprimees en r cm{sup 3} mc{sup 1} h{sup 1}): {sup 51}Cr: 0,18; {sup 56}Mn: 8,8; {sup 65}Zn: 3,05; {sup 124}Sb: 9,9; {sup 134}Cs: 9,3; {sup 137}Cs: 3,35; {sup 141}Ce: 0,46; {sup 170}Tm: 0,023; {sup 192}Ir: 24,9; {sup 203}Hg: 1,18; Ces valeurs ont ete corrigees de la contribution qu'apportent a la dose les rayonnements de fluorescence eventuellement emis par la source, sauf dans le cas du {sup 170}Tm. Dans la derniere partie de ce travail, on a compare les performances des differents dispositifs electrometriques utilises. (auteur)

  12. The activity of {gamma}-emitters as measured by ionisation chambers the determination of the specific emission coefficient {gamma} for some radio-elements (1961); Mesure de l'activite des emetteurs {gamma} par chambre d'ionisation. Determination du coefficient specifique d'emission {gamma} de quelques radioelements (1961)

    Engelmann, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1962-06-15

    gamma, permettant soit de mesurer l'activite de sources radioactives, soit de determiner le coefficient specifique d'emission {gamma} (ou coefficient K) d'un radioelement determine. Les chambres d'ionisation etudiees appartiennent a deux categories: chambre-cavites en graphite, et chambres a puits {gamma}. Pour les mesures effectuees avec une chambre-cavite, on a calcule les differents facteurs do correction dont il faut tenir compte, en particulier les corrections de geometrie et d'hygrometrie. Les corrections d'absorption et d'autoabsorption ont amene a introduire la notion 'd'energie efficace {gamma}' d'un radioelement. Dans le cas des chambres a puits, on a montre qu'une forme appropriee des 'electrodes permettait d'ameliorer leurs performances. Une des chambres decrites permet la mesure des emetteurs {beta} par le rayonnement de freinage associe. Pour la determination du coefficient K de quelques radioelements, il s'est avere commode d'utiliser une chambre a puits a parois de graphite, les mesures etant effectuees par comparaison avec un etalon de radium. La validite de la methode a ete verifiee avec quelques radioelements pour lesquels la valeur du coefficent K etait deja bien connue ({sup 24}Na, {sup 60}Co, {sup 131}I, {sup 198}Au). Pour d'autres radioelements, les valeurs suivantes ont ete obtenues (exprimees en r cm{sup 3} mc{sup 1} h{sup 1}): {sup 51}Cr: 0,18; {sup 56}Mn: 8,8; {sup 65}Zn: 3,05; {sup 124}Sb: 9,9; {sup 134}Cs: 9,3; {sup 137}Cs: 3,35; {sup 141}Ce: 0,46; {sup 170}Tm: 0,023; {sup 192}Ir: 24,9; {sup 203}Hg: 1,18; Ces valeurs ont ete corrigees de la contribution qu'apportent a la dose les rayonnements de fluorescence eventuellement emis par la source, sauf dans le cas du {sup 170}Tm. Dans la derniere partie de ce travail, on a compare les performances des differents dispositifs electrometriques utilises. (auteur)

  13. Tumour induction by small doses of ionised radiation

    Putten, L.M. van

    1980-01-01

    The effect of low doses of ionised radiation on tumour induction in animals is discussed. It is hypothesised that high doses of radiation can strongly advance tumour induction from the combination of a stimulated cell growth, as a reaction to massive cell killing, and damage to DNA in the cell nuclei. This effect has a limit below which the radiation dose causes a non-significant amount of dead cells. However in animals where through other reasons, a chronic growth stimulation already exists, only one effect, the damage of DNA, is necessary to induce tumours. A linear dose effect without a threshold level applies in these cases. Applying this hypothesis to man indicates that calculating low dose effects by linear extrapolation of high dose effects is nothing more than a reasonable approximation. (C.F.)

  14. Radicals of DNA and DNA nucleotides generated by ionising radiation

    Przybytniak, G.

    2004-01-01

    A first stage of cell processes leading to DNA damage of initiated by radical reactions. In a model system such transformations were generated by ionising radiation which involves production of electron loss and electron gain centers of the substrate and radical formation. Using cryogenic ESR spectroscopy it was found that the DNA nucleotides, which convert to radical anions upon electron capture undergo the separation of unpaired spin and charge due to protonation. Circular and linear dichroism studies enabled to conclude that iron ions(III) induce strong changes in the DNA helical structure indicating their coordination with nitrogen bases. The repair of DNA radicals produced via radiolytic oxidation, i.e. the guanine radical cation and the allyl type radical of thymine, is possible at elevated temperatures due to the involvement of sulphydryl groups. The influence of the thiol charge is then limited

  15. RF System for the MICE Demonstration of Ionisation Cooling

    Ronald, K.; et al.

    2017-04-01

    Muon accelerators offer an attractive option for a range of future particle physics experiments. They can enable high energy (TeV+) high energy lepton colliders whilst mitigating the difficulty of synchrotron losses, and can provide intense beams of neutrinos for fundamental physics experiments investigating the physics of flavor. The method of production of muon beams results in high beam emittance which must be reduced for efficient acceleration. Conventional emittance control schemes take too long, given the very short (2.2 microsecond) rest lifetime of the muon. Ionisation cooling offers a much faster approach to reducing particle emittance, and the international MICE collaboration aims to demonstrate this technique for the first time. This paper will present the MICE RF system and its role in the context of the overall experiment.

  16. Dedicated Trigger for Highly Ionising Particles at ATLAS

    Katre, Akshay; The ATLAS collaboration

    2015-01-01

    In 2012, a novel strategy was designed to detect signatures of Highly Ionising Particles (HIPs) such as magnetic monopoles, dyons or Q-balls with ATLAS. A dedicated trigger was developed and deployed for proton-proton collisions at a centre of mass energy of 8 TeV. It uses the Transition Radiation Tracker (TRT) system, applying an algorithm distinct from standard tracking ones. The high threshold (HT) readout capability of the TRT is used to distinguish HIPs from other background processes. The trigger requires significantly lower energy depositions in the electromagnetic calorimeters and is thereby capable of probing a larger range of HIP masses and charges. A description of the algorithm for this newly developed trigger is presented, along with a comparitive study of its performance during the 2012 data-taking period with respect to previous efforts.

  17. On the derivation of the ionisation threshold law

    Peterkop, R.

    1983-01-01

    The different procedures for derivation of the electron-atom ionisation threshold law have been analysed and the reasons for discrepancies in the results are pointed out. It is shown that if the wavefunction has a linear node at equal electron distances (r 1 =r 2 ), then the threshold law for the total cross section has the form σ approx. Esup(3m), where σ approx. Esup(m) is the Wannier law. The distribution of energy between escaping electrons is non-uniform and has a parabolic node at equal energies (epsilon 1 = epsilon 2 ). The linear node at opposite directions of electrons (theta = π) does not change the Wannier law but leads to a parabolic node in angular distribution at theta = π. The existence of both nodes leads to the threshold law σ approx. Esup(3m) and to parabolic nodes in energy and angular distributions. (author)

  18. Protection of the environment from ionising radiation: ethical issues

    Oughton, Deborah

    2003-01-01

    The paper identifies some of the main ethical issues concerning the protection of the environment from radiation and suggests ways in which ethics can aid in developing a system of protection. After a presentation of background on ethical theory and environmental ethics, three main issues related to environmental protection are discussed: First, the question of valuing the environment and implications for the definition of harm and monetary valuation of environmental goods; second, difficulties with scientific uncertainty and applications of the precautionary principle; and third, issues concerned with the distribution of risk and its relevance fo participation in decision-making. In summary, the paper argues that there are strong ethical grounds to provide for the protection of the environment and that, all other things being equal, there is no reason to treat ionising radiation differently to other environmental stressors

  19. Controllable isotope fractionation with thermal ionisation mass-spectrometers

    Hebeda, E.H.

    1980-01-01

    Isotopic ratios measured with thermal ionisation mass-spectrometers are biased by fractionation effects. A sample must therefore be analyzed according to the same procedures as applied for the analysis of the standard reference material. A comparison of the behaviour of the sample with that of the standard can then be used as a criterion whether the analytical results are acceptable or not. In this way it is possible to obtain reproducibilities similar to those for elements acceptable or not. In this way it is possible to obtain reproducibilities similar to those for elements where the fractionation can be determined by an internal standard. This procedure of controlled fractionation is demonstrated by means of the 88 Sr/ 86 Sr ratios measured on geological samples and the SRM 987 standard. (orig.)

  20. Review of retrospective dosimetry techniques for external ionising radiation exposures

    Ainsbury, E. A.; Bakhanova, E.; Barquinero, J. F.; Brai, M.; Chumak, V.; Correcher, V.; Darroudi, F.; Fattibene, P.; Gruel, G.; Guclu, I.; Horn, S.; Jaworska, A.; Kulka, U.; Lindholm, C.; Lloyd, D.; Longo, A.; Marrale, M.; Monteiro Gil, O.; Oestreicher, U.; Pajic, J.; Rakic, B.; Romm, H.; Trompier, F.; Veronese, I.; Voisin, P.; Vral, A.; Whitehouse, C. A.; Wieser, A.; Woda, C.; Wojcik, A.; Rothkamm, K.

    2011-01-01

    The current focus on networking and mutual assistance in the management of radiation accidents or incidents has demonstrated the importance of a joined-up approach in physical and biological dosimetry. To this end, the European Radiation Dosimetry Working Group 10 on 'Retrospective Dosimetry' has been set up by individuals from a wide range of disciplines across Europe. Here, established and emerging dosimetry methods are reviewed, which can be used immediately and retrospectively following external ionising radiation exposure. Endpoints and assays include dicentrics, translocations, premature chromosome condensation, micronuclei, somatic mutations, gene expression, electron paramagnetic resonance, thermoluminescence, optically stimulated luminescence, neutron activation, haematology, protein biomarkers and analytical dose reconstruction. Individual characteristics of these techniques, their limitations and potential for further development are reviewed, and their usefulness in specific exposure scenarios is discussed. Whilst no single technique fulfils the criteria of an ideal dosemeter, an integrated approach using multiple techniques tailored to the exposure scenario can cover most requirements. (authors)

  1. Protection of the environment from ionising radiation: ethical issues

    Oughton, D.

    2002-01-01

    The paper identifies some of the main ethical issues concerning the protection of the environment from radiation and suggests ways in which ethics can aid in developing a system of protection. After a presentation of background on ethical theory and environmental ethics, three main issues related to practical environmental protection are discussed: First, the question of who or what has moral standing; second the appropriate level of protection; and third compatibility with other environmental stressors. In summary, the paper argues that there are strong ethical grounds for efforts to provide for the protection of the environment and that, all other things being equal, there is no reason to treat ionising radiation differently to other environmental stressors. (author)

  2. Studies of Non-Targeted Effects of Ionising Radiation

    Oleg V Belyakov; Heli Mononen; Marjo Peraelae

    2006-01-01

    The discovery of ionising radiation induced non-targeted effects is important for understanding the dose-response mechanisms relevant to low dose irradiation in vivo. One important question is whether the non-targeted effects relates to a protective mechanism or whether, conversely, it amplifies the number of cells damaged by the isolated radiation tracks of low dose exposures leading to an increased risk of carcinogenesis. One theory supported by the experimental data obtained during this project is that the main functions of the non-targeted effects are to decrease the risk of transformation in a multicellular organism exposed to radiation. Differences in the gene expression profiles, temporal and spatial patterns of key proteins expressed in directly irradiated and bystander cells may determine how the cells ultimately respond to low doses of radiation. Such a mechanism of co-operative response would make the tissue system much more robust. (N.C.)

  3. Studies of Non-Targeted Effects of Ionising Radiation

    Oleg V Belyakov; Heli Mononen; Marjo Peraelae [STUK - Radiation and Nuclear Safety Authority, Helsinki (Finland)

    2006-07-01

    The discovery of ionising radiation induced non-targeted effects is important for understanding the dose-response mechanisms relevant to low dose irradiation in vivo. One important question is whether the non-targeted effects relates to a protective mechanism or whether, conversely, it amplifies the number of cells damaged by the isolated radiation tracks of low dose exposures leading to an increased risk of carcinogenesis. One theory supported by the experimental data obtained during this project is that the main functions of the non-targeted effects are to decrease the risk of transformation in a multicellular organism exposed to radiation. Differences in the gene expression profiles, temporal and spatial patterns of key proteins expressed in directly irradiated and bystander cells may determine how the cells ultimately respond to low doses of radiation. Such a mechanism of co-operative response would make the tissue system much more robust. (N.C.)

  4. Protection of the environment from ionising radiation: ethical issues.

    Oughton, Deborah

    2003-01-01

    The paper identifies some of the main ethical issues concerning the protection of the environment from radiation and suggests ways in which ethics can aid in developing a system of protection. After a presentation of background on ethical theory and environmental ethics, three main issues related to environmental protection are discussed: First, the question of valuing the environment and implications for the definition of harm and monetary valuation of environmental goods; second, difficulties with scientific uncertainty and applications of the precautionary principle; and third, issues concerned with the distribution of risk and its relevance for participation in decision-making. In summary, the paper argues that there are strong ethical grounds to provide for the protection of the environment and that, all other things being equal, there is no reason to treat ionising radiation differently to other environmental stressors. Copyright 2002 Elsevier Science Ltd.

  5. Ionisation of L subshells of heavy atoms by deuteron collision

    Sokhi, R.S.; Crumpton, D.; Trautmann, D.

    1989-01-01

    L i subshell ionisation cross sections for 1.2-3.0 MeV deuteron impact on thin targets of W, Au, Pb and Bi have been measured experimentally. Measurements were made with the Birmingham University's 3MV Dynamitron accelerator and the cross sections were deduced from the emitted L X-rays. These cross sections and their ratios have been compared graphically with the ECPSSR and RHSCA models. The ECPSSR model underestimates the measured L 2 subshell cross sections but shows very good agreement with the L 3 subshell values. The RHSCA theory in general exhibits good agreement with the measured cross sections for the L 1 and L 2 subshells but overestimates the L 3 cross sections by up to 60%. (orig.)

  6. The use of ionising radiation screening devices in airports

    Lazo, T.

    2010-01-01

    Although the NEA generally focuses on radiological protection at nuclear power plants and related facilities, it also addresses other areas of radiological protection of interest to member countries. A particular subject of recent importance concerns the use of ionising radiation screening devices as part of airport security efforts. Modern body scanners can produce human images that can be used to detect weapons that may be hidden beneath a person's clothing. Heightened concerns over terrorist threats to airline flights have prompted many countries to consider the use, or expanded use of body scanners. The use of such devices raises a wide series of questions, some of which concern the radiological protection of those who might be scanned. As such, the Inter-Agency Committee on Radiation Safety (IACRS), an expert body in which the NEA works together with several other international organisations addressing radiological protection issues, recently developed a joint information paper laying out the key radiological protection and other issues that should be or have been considered when making decisions as to whether ionising radiation body scanners should be deployed in airports. This article provides an overview of the information paper. In assessing the possible use of X-ray body scanners, there are two significant radiological protection issues that may be of relevance with regard to the government decision whether their use is justified. First, although the individual exposures are very low, the exposure experienced by the scanned population as a whole will depend on whether all passengers are systematically scanned, or alternatively whether passengers are selected for scanning randomly or on the basis of specific criteria. The manner in which passengers would be selected would need to be known in order to appropriately assess the full radiological protection impact of scanner use. Second, the use of X-ray body scanners on sensitive groups, such as pregnant

  7. Organisation et mise en oeuvre d'une infrastructure reglementaire nationale chargee de la protection contre les rayonnements ionisants et de la surete des sources de rayonnements. Rapport interimaire pour observations; Organization and implementation of a national regulatory infrastructure governing protection against ionizing radiation and the safety of radiation sources. Interim report for comment

    NONE

    2001-11-01

    A number of IAEA Member States are undertaking to strengthen their radiation protection and safety infrastructures in order to facilitate the adoption of the requirements established in the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (the Standards). In this connection, the IAEA has developed a technical co-operation programme (Model Project on Upgrading Radiation Protection Infrastructure) to improve radiation protection and safety infrastructures in 51 Member States, taking into account national profiles and needs of the individual participating, countries. The present report deals with the elements of a regulatory infrastructure for radiation protection and safety and intends to facilitate the, implementation of the Basic Safety Standards in practice. It takes into account the proposals in an earlier report, IAEA-TECDOC-663, but it has been expanded to include enabling legislation and modified to be more attuned to infrastructure issues related to implementation of the Standards. The orientation is toward infrastructures concerned with protection and safety for radiation sources used in medicine, agriculture, research, industry and education rather than infrastructures for protection and safety for complex nuclear facilities. It also discusses options for enhancing the effectiveness and efficiency of the infrastructure in accordance with the size and scope of radiation practices and available regulatory resources within a country.

  8. Gamma radiation in space and in the atmosphere; Rayonnement gamma dans l'espace et dans l'atmosphere

    Rocchia, R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1966-07-01

    We have shown that the {gamma} radiation existing in the atmosphere is caused mainly by the Bremsstrahlung of the electrons of the electromagnetic cascades ({approx} 50 per cent of the measured radiation), by the 511 keV radiation produced by the annihilation of positrons created in cascades (8 per cent of the measured intensity) and by the Compton {gamma} degradation of this line (30 per cent of the measured intensity). The rest, slightly over 10 per cent, must be attributed to secondary causes such as the nuclear de-excitation {gamma} to the internal Bremsstrahlung of charged particles created in nuclear stars, and to charged particles crossing our detector, since the latter was not fitted with a device for rejecting these particles. Experiments carried out in rockets at Colomb-Bechar confirm these results and have made it possible to detect and measure a primary {gamma} radiation having an intensity of {approx} 2 {gamma} cm{sup 2} s{sup -1} above 100 keV. The primary spectrum obeys an approximate E{sup -2} law. (author) [French] Nous avons montre que le rayonnement {gamma} existant dans l'atmosphere est provoque principalement por le bremsstrohlung des electrons des cascades electromagnetiques ({approx} 50 pour cent du rayonnement mesure), au rayonnement 511 keV provoque par l'annihilation des positrons crees dans les cascades (8 pour cent de l'intensite mesuree) et aux {gamma} de degradation Compton de cette raie (30 pour cent de l'intensite mesuree). Le reste, soit un peu plus de 10 pour cent, doit etre attribue a des causes secondaires telles que les {gamma} de desexcitation nucleaire, le bremsstrahlung interne des particules chargees creees dans les etoiles nucleaires, et aux particules chargees traversant notre detecteur car celui-ci ne comportait pas de dispositif de rejet de ces particules. Les experiences faites en fusees a Colomb-Bechar ont confirme ces resultats et permis de detecter et mesurer un rayonnement {gamma} primaire dont l

  9. Technical Developments in the USAEC Process Radiation Development Program; Etudes technologiques dans le cadre du programme de mise au point d'applications industrielles des rayonnements de la CEA-EU; Issledovaniya v oblasti promyshlennogo primeneniya izluchenij, vkhodyashchie v programmu komissii po atomnoj ehnergii USAEC; Progresos tecnicos en el programa de la USAEC para el fomento de la irradiacion industrial

    Machurek, J. E.; Stein, M. H. [Division of Isotopes Development, USAEC, Washington, DC (United States)

    1963-11-15

    des rayonnements ionisants. Les auteurs donnent les resultats de quatorze de ces travaux; certains sont decrits succinctement dans le memoire et d'autres sont exposes en detail dans les comptes rendus. Les sujets traites sont les suivants: 1. Preparation de produits bois-matiere plastique en utilisant des rayons gamma pour induire la polymerisation. 2. Emploi du rayonnement beta des produits de fission pour l'hydrogenation de la houille et de ses derives pour produire des hydrocarbures liquides. 3. Production de semi-conducteurs dans lesquels on repartit les impuretes selon un schema spatial fixe a l'avance, a l'aide de transmutations neutroniques. 4. Polymerisation radioinduite de l'ethylene et de ses copolymeres. 5. Etude fondamentale du mecanisme et de la cinetique des reactions radioinduites. 6. La. radiochimie dans la fluoration de divers composes aromatiques. 7. Emploi de monomeres polyfonctionnels pour augmenter la radioreticulation du polyethylene, du polypropylene, du polyisobutylene et de l'acetate de cellulose. 8. Effets du gonflement, des contraintes et d e la temperature sur les proprietes physiques et chimiques des polymeres produits au moyen des rayonnements. 9. Influence des facteurs structurels sur les modifications radioinduites dans les polymeres conduisant a la copolymerisation par greffage. 10. Utilisation des rayonnements pour modifier les proprietes de matieres textiles. 11. Reactions radioinduites utilisant le krypton-85. 12. Preparation d'un ''Manuel des rayonnements''. 13. Utilisation de la liaison organometallique en dosimetrie des rayons gamma intenses. 14. Mise au point d'un dosimetre a cellule solaire. (author) [Spanish] Dentro del marco de su programa de fomento de la irradiacion industrial, la Comision de Energia Atomica de los Estados Unidos ha emprendido una amplia serie de investigaciones cuyo objetivo principal es estimular un progreso tecnologico que facilite el empleo de las radiaciones ionizantes en la produccion industrial. Los

  10. Making ionising radiation a real experience for high school science students

    Whitlock, J.; Lang, P.; De La Matter, D.; Hinman, P.; White, B.

    2009-01-01

    The Canadian public has little understanding of ionising radiation due in part to its treatment in popular media. In principle, students learn about ionising radiation in their school science classes. Developments in science curricula are providing more education opportunities for this subject. The Canadian Nuclear Society's program for introducing real, personal experience with ionising radiation in the classroom is starting to make a difference. The demand is expected to exceed the resources of the CNS and the program is being developed to facilitate external support. This paper summarizes the need, the history of this program development, and the path forward. (author)

  11. Total Counting and Spectroscopy in the Assessment of Alpha Radioactivity in Human Tissues; Determination de la Radioactivite Alpha des Tissus Humains par Dosage de l'Activite Globale et Spectroscopie; Obshchee izmerenie i spektroskopiya pri opredelenii al'fa-radioaktivnosti tkanej cheloveka; Evaluacion de la Actividad Alfa en los Tejidos Humanos por Recuento Global y Espectroscopia

    Mayneord, W. V.; Hill, C. R. [Physics Department, Institute of Cancer Research, Royal Cancer Hospital, Clifton Avenue, Belmont, Surrey (United Kingdom)

    1964-10-15

    A seven-year programme of measurements of alpha radioactivity is briefly reviewed. The programme which was based initially on a sensitive and simple counting technique, using thin zinc cadmium sulphide screens, now employs in addition techniques of alpha spectroscopy developed for work with very large area low-specific-activity sources. These techniques are capable of measuring specific activities down to 10{sup -13} c/g and can in certain cases provide energy resolution of the order of 40 keV together with independent identification based on half-life measurements. Two alpha spectrometers are described which have been used on a wide variety of human and environmental materials. Particular attention has been given to the study of Po{sup 210}, now known to be present in a variety of foods and human tissues. Techniques are also described for the study of Pu{sup 239} in the atmosphere and examples given of .the results of measurements of low-level air contamination with this material. Techniques for the measurement of Pu{sup 239} in normal human tissues are described and some results given. Consideration is given to the contribution made by Po{sup 210} to the natural background radiation dose-rate in human bone and reproductive organs. It is shown that this contribution may be a significant fraction of the total dose received. (author) [French] L'auteur fait brievement le point de l'execution d'un programme septennal de mesures de la radioactivite alpha. Au debut, on procedait seulement a un dosage simple et sensible au moyen d'ecrans minces de sulfure de cadmium et de zinc; maintenant, ce procede est complete par l'emploi de methodes de spectroscopie alpha qui ont ete mises au point a l'occasion de travaux sur des sources a faible activite specifique et a tres grande surface. Ces methodes permettent de mesurer des activites specifiques aussi faibles que 10{sup -13} c/g, d'obtenir, dans certains cas, une resolution en energie de l'ordre de 40 keV et, independamment, d

  12. Using ionising radiation against terrorism and contrabandism - dosimetric problems

    Ankerhold, U.; Hupe, O.; Buchholz, G.

    2006-01-01

    As will be explained in more detail in a talk at this conference, the personnel X-ray scanners can be divided into two groups, one using the transmitted X rays for image creation, the other one using the Compton back scatters X-rays. In the case of a backscatter scanner, a narrow, pencil -like X-ray beam is produced by a rotating chopper-wheel. The person/object is scanned in a raster scan pattern. The backscattered X-rays of all points are measured and recorded. The transmission X-ray scanner can use both fan-like and pencil like X-ray beams. The transmission detectors are installed behind the object and detect the absorption of the scanned person. Due to the very low dose values of the X-ray scanner systems in combination with a high dose rate in the direct beam for a short irradiation time, special dosemeters have to be used. In the literature and in manufacturers' specifications, the dose values given for some systems are in the range from 0.05 μSv to 5 μSv per scan with a typical irradiation time of a few milliseconds. Due to this pulse-like character of the radiation fields, the dose rate is several sieverts per hour. For the measurements of the investigated scanner, dosemeters were therefore needed having the capability to measure low doses at high dose rates and to measure in pulsed radiation fields. For the optimization of the measurements, the use of measuring devices with a direct indication is necessary. Ionisation chambers are the most suitable measuring instruments to fulfill these requirements. The difficulty for the measurements with an ionisation chamber is that the leakage charge integrated over time can reach values at the level of the expected radiation-produced charge. Additionally unpredictable variations of the leakage charge can be in the same order of magnitude as the expected signal. This challenge led to the development of a special electronics which allow the execution of time-resolved measurements. With this time resolution, it is

  13. Medical exposure to ionising radiation and the risk of brain tumours

    Blettner, Maria; Schlehofer, Brigitte; Samkange-Zeeb, Florence

    2007-01-01

    BACKGROUND: The role of exposure to low doses of ionising radiation in the aetiology of brain tumours has yet to be clarified. The objective of this study was to investigate the association between medically or occupationally related exposure to ionising radiation and brain tumours. METHODS: We...... used self-reported medical and occupational data collected during the German part of a multinational case-control study on mobile phone use and the risk of brain tumours (Interphone study) for the analyses. RESULTS: For any exposure to medical ionising radiation we found odds ratios (ORs) of 0.63 (95...... regions. CONCLUSION: We did not find any significant increased risk of brain tumours for exposure to medical ionising radiation....

  14. Critical ionisation velocity and the dynamics of a coaxial plasma gun

    Raadu, M.A.

    1978-01-01

    The dynamics of an ionising wave in a coaxial plasma gun with an azimuthal bias magnetic field is analysed in a theoretical model. Only the radial dependence is treated and instead of including a treatment of the energy balance two separate physical assumptions are made. In the first case it is assumed that the total internal electric field is given by the critical ionisation velocity condition and in the second that the ionisation rate is constant. For consistency wall sheaths are assumed to match the internal plasma potential to that of the walls. On the basis of momentum and particle balance the radial dependence of the electron density, current density, electric field and drift velocity are found. An electron source is required at the cathode and the relative contribution from ionisation within the plasma is deduced. The assumption that there are no ion sources at the electrodes leads to a restriction on the possible values of the axial electric field. (author)

  15. Distorted-wave calculations of electron impact ionisation in the Ni isonuclear sequence

    Griffin, D C; Pindzola, M S

    1988-10-14

    Electron impact ionisation cross sections for Ni/sup +/, Ni/sup 3+/, Ni/sup 5+/, Ni/sup 6+/, Ni/sup 7+/, Ni/sup 8+/, Ni/sup 12+/, Ni/sup 14+/, and Ni/sup 16+/ are calculated in the distorted-wave approximation. These calculations include contributions from direct ionisation and inner-shell excitation followed by autoionisation. For Ni/sup 12+/, Ni/sup 14+/, and Ni/sup 16+/ we report not only on ionisation cross sections from the ground states but also from the metastable states of these ions. Experimental cross section measurements exist for all ions reported here, except Ni/sup 16+/. The agreement between experiment and theory is reasonably good and improves with ionisation stage.

  16. Rapid detection of nicotine from breath using desorption ionisation on porous silicon.

    Guinan, T M; Abdelmaksoud, H; Voelcker, N H

    2017-05-04

    Desorption ionisation on porous silicon (DIOS) was used for the detection of nicotine from exhaled breath. This result represents proof-of-principle of the ability of DIOS to detect small molecular analytes in breath including biomarkers and illicit drugs.

  17. Impact ionisation rate calculations in wide band gap semiconductors

    Harrison, D.

    1998-09-01

    Calculations of band-to-band impact ionisation rates performed in the semi-classical Fermi's Golden Rule approximation are presented here for the semiconductors GaAs, In 0.53 Ga 0.47 As and Si 0.5 Ge 0.5 at 300K. The crystal band structure is calculated using the empirical pseudopotential method. To increase the speed with which band structure data at arbitrary k-vectors can be obtained, an interpolation scheme has been developed. Energies are quadratically interpolated on adapted meshes designed to ensure accuracy is uniform throughout the Brillouin zone, and pseudowavefunctions are quadratically interpolated on a regular mesh. Matrix elements are calculated from the pseudowavefunctions, and include the terms commonly neglected in calculations for narrow band gap materials and an isotropic approximation to the full wavevector and frequency dependent dielectric function. The numerical integration of the rate over all distinct energy and wavevector conserving transitions is performed using two different algorithms. Results from each are compared and found to be in good agreement, indicating that the algorithms are reliable. The rates for electrons and holes in each material are calculated as functions of the k-vector of the impacting carriers, and found to be highly anisotropic. Average rates for impacting carriers at a given energy are calculated and fitted to Keldysh-type expressions with higher than quadratic dependence of the rate on energy above threshold being obtained in all cases. The average rates calculated here are compared to results obtained by other workers, with reasonable agreement being obtained for GaAs, and poorer agreement obtained for InGaAs and SiGe. Possible reasons for the disagreement are investigated. The impact ionisation thresholds are examined and k-space and energy distributions of generated carriers are determined. The role of threshold anisotropy, variation in the matrix elements and the shape of the bands in determining

  18. Metabolic changes in broiler chickens exposed to low dose of ionising radiation

    Danova, D.; Kafka, I.; Kalenicova, Z.; Petrovova, E.; Toropila, M.

    2008-01-01

    In our experiment broiler chickens, 28-day old, were exposed to single whole- body dose 3 Gy of ionising radiation in time gap 3., 7., 14. and 21 day. We applied zinc to organism of chicks after irradiation. We observed changes of concentrations of cholesterol and glucose in blood serum. From obtained results it is evident that despite relative high resistance of poultry to irradiation, it reacts strongly to ionising radiation even at laboratory levels. (authors)

  19. The potential use of ionising energy treatment in Queensland's horticultural industries

    Heather, N.W.; Sheehy, P.T.; Muirhead, I.F.; Brown, B.I.; Hassall, R.N.

    1985-01-01

    The potential application of ionising energy treatment technology in Queensland falls into three categories: insect disinfestation, disease control and quality improvement. The technology fulfils the requirements of a disinfestation treatment against Queensland fruit fly and other pests of quarantine importance in respect to efficacy, absence of phytotoxicity, absence of residues and, on technical considerations would be an ideal replacement for the fumigant EDB. The report examines the purposes of ionising energy treatment, economic and marketing aspects and research needs

  20. Proceedings. Protection of the natural environment. International symposium on ionising radiation

    Amiro, B.; Johansson, Gunnar; Larsson, Carl-Magnus; Luening, M.

    1996-01-01

    The symposium was organised jointly by the Swedish Radiation Protection Institute and the Atomic Energy Control Board of Canada. The programme was organised around six major topics: Biological effects of ionising radiation; Ecological effects of ionising radiation; Behaviour and transport of radionuclides in the natural environment; Criteria for environmental protection; Assessment methodology; and Social and economic aspects. All 86 contributions (excluding the opening addresses) have been separately indexed

  1. Dosimetry with tissue-equivalent ionisation chambers in fast neutron fields for biomedical applications

    Zoetelief, J.; Broerse, J.J.

    1983-01-01

    The use of calibrated tissue-equivalent (TE) ionisation chambers is commonly considered to be the most practical method for total absorbed dose determinations in mixed neutron-photon fields for biomedical applications. The total absorbed dose can be derived from the charge produced within the cavity of an ionisation chamber employing a number of physical parameters. To arrive at the charge produced in the cavity several correction factors have to be introduced which are related to the operational characteristics of the chambers. Information on the operational characteristics of four TE ionisation chambers is presented in relation to ion collection, density and composition of gas in the cavity, wall thickness and effective point of measurement. In addition, some recent results from an ionisation chamber operated at high gas pressures are presented. The total absorbed doses derived from TE ionisation chambers show agreement within the uncertainty limits with results from other independent dosimetry methods, i.e., differential fluence measurements and a TE calorimeter. Conscientious experimentation and a common data base can provide dosimetry results with TE ionisation chambers with variations of less than +-2%. (author)

  2. Education and training issues in individual monitoring of ionising radiation

    Dimitriou, P.; Kamenopoulou, V.

    2011-01-01

    The present article deals with the education and training (E and T) issues of individual monitoring (IM) of ionising radiation, based on the requirements provided by the Basic Safety Standards EURATOM Directive and the European Commission Technical Recommendations for IM of external radiation. The structure and the objectives of E and T programmes addressed to the staff of dosimetry services, in order to allow the recognition and ensure the continuity of expertise are discussed. The necessity for the establishment of a national strategy for building competence in IM through information, education, training and retraining programmes, addressed to the individually monitored personnel is underlined. The train the trainers' concept is recognised as being an important tool for optimising resources and transferring the skills necessary for building competence. The conditions under which an efficient train the trainers' approach can be established are discussed. Examples of curricula concerning the key persons involved in the provision of E and T in occupational radiation protection are also given. (authors)

  3. The Laboratory appraisal of ionisation chamber smoke detectors

    Wilkins, B.T.; Dixon, D.W.

    1980-01-01

    The present paper traces the development of the National Radiological Protection Board test programme for ionisation chamber smoke detectors, describes methods and summarises the results from the detectors which have been examined by NRPB. The results of dose rate and surface contamination measurements are included as well as data from the destructive testing programme. The 600degC fire test continues to produce the most interesting results especially concerning material incompatibility problems. Some source holder materials invariably cause loss of source integrity during a fire, as do certain methods of fixing the foil to the holder. In addition plastics containing certain fire retardants produce corrosive combustion products which cause loss of integrity of otherwise well-mounted sources. Fire tests at 1200degC were discontinued at an early stage in the programme since it was felt there was no additional information to be gained. As all detectors are now tested with respect to the NEA recommendations, the 1200degC incineration tests have been reinstated as part of the test programme. The criterion of failure relates to activity which becomes airborne rather than the total leakage concept which applies at the lower temperature. All the detectors submitted will ultimately be subjected to this test, and some preliminary results are presented here. (H.K.)

  4. Application of ionising radiation to the pharmaceutical industry

    Dittmar, E.

    1975-01-01

    Pharmacons, commonly called 'Drugs', are subject to a many-sided procedure of development before they are released on the market and reach the patient. Again and again they are submitted to controls for safety reasons and at least seven (sometimes nine or ten) years pass before the active substance has made its way from chemistry through many trials with animals in experimental pathology and through the laboratories of the biochemistry department. Ionising radiation is used in each field of drug research as an additional method for obtaining information. In chemistry the structure of molecules can be detected by X-ray diffraction, and the active component elucidated. In the teratology section of experimental pathology the foetus just before delivery and newborn animals are X-rayed. This is in order to find out skeletal malformations that might have occurred during feeding of the substance in question during gestation. In biochemistry the pharmacon is labelled with a suitable radioactive isotope. Its way through the body can then be followed by measuring absorption rate, distribution, binding and elimination. It is also important to explore the influence of the drug on the organism and the reverse - how the pharmacon is influenced by the organism. This means examining the metabolites of the drug and the mechanism of action by means of serial auto-radiography and clearance or excretion studies. Gamma rays are employed for sterilisation of ointment tubes and vials just before filling. Sterilisation of the pharmacon is discussed. (author)

  5. Occupational Exposure to Ionising Radiation in Greece (1994-1998)

    Kamenopoulou, V.; Drikos, G.; Dimitriou, P.

    2000-01-01

    This study was scheduled in order to analyse the individual annual dose information on classified workers in Greece, monitored and assessed by the central dosimetry service at the Greek Atomic Energy Commission for the years 1994-98. This service provides film badges to about 7500 workers all over the country on a monthly basis. Dose summaries were recorded and processed by the Dose Registry Information System, the database of which has been totally renewed since 1994. The statistical analysis provided refers to and deals with the mean annual dose, the collective dose, the distribution of the dose over the different specialities and the number of workers that have exceeded any of the established dose levels. Results concerning the annual dose summaries demonstrate a decrease in the collective and the mean individual dose to workers in the year 1995 and a slight but steady year-by-year increase thereafter during the period under consideration. This increasing tendency is discussed along with the increase in the ionising radiation applications, especially those in the medical sector, the change of the positioning of the film badge and the quality control measures provided by Greek law for radiation laboratories. (author)

  6. International conference on individual monitoring of ionising radiation

    Vanhavere, Filip

    2016-01-01

    This special issue of the journal Radiation Protection Dosimetry is dedicated to the Proceedings of the International Conference on Individual Monitoring of Ionising Radiation (IM2015), which is the fifth of a series of conferences dealing with individual monitoring. This conference series is initiated by EURADOS, the European Radiation Dosimetry Group, and is organised every 5 years. In 2015, the conference was jointly organised by the Belgian Nuclear Research Centre (SCK.CEN), AV Controlatom, and the Vrije Universiteit Brussel. It brought together scientists from regulatory authorities, individual monitoring services (IMS), research bodies, European networks and companies, for the purpose of facilitating the dissemination of knowledge, exchanging experiences and promoting new ideas in the field of individual monitoring. After the conference, 124 papers were submitted for publication in these peer-reviewed proceedings. From these, 103 were finally accepted for publication. The help of the numerous referees and the guest editors is very much appreciated. These proceedings provide a full image of the IM2015 conference. The high-level publications will be useful to improve the state of individual monitoring all over the world and aim to inspire many scientists to continue their work on a better monitoring of radiologically exposed workers

  7. Biomarkers specific to densely-ionising (high LET) radiations

    Brenner, D.J.; Okladnikova, N.; Hande, P.; Burak, L.; Geard, C.R.; Azizova, T.

    2001-01-01

    There have been several suggestions of biomarkers that are specific to high LET radiation. Such a biomarker could significantly increase the power of epidemiological studies of individuals exposed to densely-ionising radiations such as alpha particles (e.g. radon, plutonium workers, individuals exposed to depleted uranium) or neutrons (e.g. radiation workers, airline personnel). We discuss here a potentially powerful high LET biomarker (the H value) which is the ratio of induced inter-chromosomal aberrations to intra-arm aberrations. Both theoretical and experimental studies have suggested that this ratio should differ by a factor of about three between high LET radiation and any other likely clastogen, and will yield more discrimination than the previously suggested F value (ratio of inter-chromosomal aberrations to intra-chromosomal inter-arm aberrations). Evidence of the long-term stability of such chromosomal biomarkers has also been generated. Because these stable intra-arm and inter-chromosomal aberrations are (1) frequent and (2) measurable at long times after exposure, this H value appears to be a practical biomarker of high LET exposure, and several in vitro studies have confirmed the approach for unstable aberrations. The approach is currently being tested in a population of Russian radiation workers exposed several decades ago to high- or low LET radiation. (author)

  8. Medical effects of low doses of ionising radiation

    Coggle, J.E.

    1990-01-01

    Ionising radiation is genotoxic and causes biological effects via a chain of events involving DNA strand breaks and 'multiply damaged sites' as critical lesions that lead to cell death. The acute health effects of radiation after doses of a few gray, are due to such cell death and consequent disturbance of cell population kinetics. Because of cellular repair and repopulation there is generally a threshold dose of about 1-2 Gy below which such severe effects are not inducible. However, more subtle, sub-lethal mutational DNA damage in somatic cells of the body and the germ cells of the ovary and testis cause the two major low dose health risks -cancer induction and genetic (heritable) effects. This paper discusses some of the epidemiological and experimental evidence regarding radiation genetic effects, carcinogenesis and CNS teratogenesis. It concludes that current risk estimates imply that about 3% of all cancers; 1% of genetic disorders and between 0% and 0.3% of severe mental subnormality in the UK is attributable to the ubiquitous background radiation. The health risks associated with the medical uses of radiation are smaller, whilst the nuclear industry causes perhaps 1% of the health detriment attributable to background doses. (author)

  9. Ionisation and dissociation of water induced by swift multicharged ions

    Legendre, S.

    2006-02-01

    Ionization and dissociation of water molecules and water clusters induced by 11.7 MeV/A Ni 25+ ions were carried out by imaging techniques. Branching ratios, ionisation cross sections and Kinetic Energy Released distributions have been measured together with fragmentation dynamics studies. Multiple ionization represents approximately 30% of the ionizing events. Double ionization produces in significant way atomic oxygen, considered as a possible precursor of the large production of HO 2 radical in liquid water radiolysis by ions of high Linear Energy Transfer. We evidence a strong selectivity of bond breakage in the case of ion-induced HOD fragmentation. Once the molecule doubly ionized, the breakage of the O-H bond is found 6.5 times more probable than that of the O-D bond. A semi-classical calculation simulating the fragmentation dynamics on the potential energy surface of the ground-state of di-cation H 2 O 2+ makes possible to as well reproduce the preferential nature of the breakage of the O-H bond as the position and the shift of the kinetic energy distributions. First results concerning interaction with water clusters are also reported. Measurements in coincidence are carried out giving access to correlation, with the distributions in energy and angle of the emitted fragments. Mass spectrum points fast intra-cluster proton transfer, leading to the emission of protonated clusters. (author)

  10. Thermoluminescent properties of CVD diamond: applications to ionising radiation dosimetry

    Petitfils, A.

    2007-09-01

    Remarkable properties of synthetic diamond (human soft tissue equivalence, chemical stability, non-toxicity) make this material suitable for medical application as thermoluminescent dosimeter (TLD). This work highlights the interest of this material as radiotherapy TLD. In the first stage of this work, we looked after thermoluminescent (TL) and dosimetric properties of polycrystalline diamond made by Chemically Vapor Deposited (CVD) synthesis. Dosimetric characteristics are satisfactory as TLD for medical application. Luminescence thermal quenching on diamond has been investigated. This phenomenon leads to a decrease of dosimetric TL peak sensitivity when the heating rate increases. The second part of this work analyses the use of synthetic diamond as TLD in radiotherapy. Dose profiles, depth dose distributions and the cartography of an electron beam obtained with our samples are in very good agreement with results from an ionisation chamber. It is clearly shown that CVD) diamond is of interest to check beams of treatment accelerators. The use of these samples in a control of treatment with Intensity Modulated Radiation Therapy underlines good response of synthetic diamond in high dose gradient areas. These results indicate that CVD diamond is a promising material for radiotherapy dosimetry. (author)

  11. Medical effects and risks of exposure to ionising radiation

    Mettler, Fred A

    2012-01-01

    Effects and risk from exposure to ionising radiation depend upon the absorbed dose, dose rate, quality of radiation, specifics of the tissue irradiated and other factors such as the age of the individual. Effects may be apparent almost immediately or may take decades to be manifest. Cancer is the most important stochastic effect at absorbed doses of less than 1 Gy. The risk of cancer induction varies widely across different tissues; however, the risk of fatal radiation-induced cancer for a general population following chronic exposure is about 5% Sv −1 . Quantification of cancer risk at doses of less than 0.1 Gy remains problematic. Hereditary risks from irradiation that might result in effects to offspring of humans appear to be much lower and any such potential risks can only be estimated from animal models. At high doses (over 1 Gy) cell killing and modification causes deterministic effects such as skin burns, and bone marrow depression, in which case immunosuppression becomes a critical issue. Acute whole body penetrating gamma irradiation at doses in excess of 2 Gy results in varying degrees of acute radiation sickness and doses over 10 Gy are usually lethal as a result of combined organ injury. (note)

  12. Martian sub-surface ionising radiation: biosignatures and geology

    J. M. Ward

    2007-07-01

    Full Text Available The surface of Mars, unshielded by thick atmosphere or global magnetic field, is exposed to high levels of cosmic radiation. This ionising radiation field is deleterious to the survival of dormant cells or spores and the persistence of molecular biomarkers in the subsurface, and so its characterisation is of prime astrobiological interest. Here, we present modelling results of the absorbed radiation dose as a function of depth through the Martian subsurface, suitable for calculation of biomarker persistence. A second major implementation of this dose accumulation rate data is in application of the optically stimulated luminescence technique for dating Martian sediments.

    We present calculations of the dose-depth profile in the Martian subsurface for various scenarios: variations of surface composition (dry regolith, ice, layered permafrost, solar minimum and maximum conditions, locations of different elevation (Olympus Mons, Hellas basin, datum altitude, and increasing atmospheric thickness over geological history. We also model the changing composition of the subsurface radiation field with depth compared between Martian locations with different shielding material, determine the relative dose contributions from primaries of different energies, and discuss particle deflection by the crustal magnetic fields.

  13. The application of ionising radiation in industrial wastewater treatment technology

    Kos, L. [Inst. of Knitting Technology and Techniques, Lodz (Poland); Perkowski, J. [Inst. of Applied Radiation Chemistry, Technical Univ. of Lodz, Lodz (Poland); Ledakowicz, S. [Dept. of Bioprocess Engineering, Technical Univ. of Lodz, Lodz (Poland)

    2003-07-01

    An attempt was made to apply radiation techniques in the treatment of industrial wastewater from a dairy, brewery and sugar factory. For degradation of pollutants present in the wastewater, the following methods were used: irradiation, irradiation combined with aeration, ozonation, and combined irradiation and ozonation. For all three types of wastewater, the best method among these listed above appeared to be the method of irradiation combined with ozonation. Most degradable was the wastewater produced in sugar factories, and the least biodegradable appeared to be dairy wastewater. Depending on the dose of ozone and radiation, a maximum 60% reduction of COD was obtained. No effect of the wastewater aeration on its degradation by radiation was found. Changes in the content of mineral compounds were observed in none of the cases. The process of biological treatment of wastewater was carried out in a low-loaded, wetted bed. Pretreatment of the wastewater had no significant effect on the improvement of the biological step operation. Some effect was observed only in the case of the wastewater coming from a sugar factory. For medium concentrated wastewater from food industry, it is not economically justified to apply the pretreatment with the use of ionising radiation. (orig.)

  14. International Conference on Low Doses of Ionising Radiation

    McEwan, A.C.

    1998-01-01

    Is there a threshold? and is a little radiation good for you? were two questions raised at the International Conference on Low Doses of Ionising Radiation : Biological Effects and Regulatory Control, jointly organised by the IAEA and WHO, and convened in Seville, Spain, over 17-21 November 1997. The answer to both these questions appears to be 'Maybe', but the answer has no present implications for radiation protection practice and regulation. The conference which had over 500 participants from 65 countries, was organised around ten fora which explored basic molecular mechanisms of radiation effects, through to radiation protection principles and implementation in practices and interventions. Each forum was introduced by an overview presentation by an invited keynote speaker. Brief presentations of a few of the proffered papers followed, and then open discussion. There was opportunity for all proffered papers to be presented as posters. The fora, which occupied 3 full days, were preceded by reports on biological effects of radiation from international orgnaisations, and on related international conferences held in the recent past. The fora were followed by round table presentations of regulatory control and scientiFic research, and a summary session drawing together conclusions on the topic areas of the conference. (author)

  15. A review of multiple stressor studies that include ionising radiation

    Vanhoudt, Nathalie; Vandenhove, Hildegarde; Real, Almudena; Bradshaw, Clare; Stark, Karolina

    2012-01-01

    Studies were reviewed that investigated the combined effects of ionising radiation and other stressors on non-human biota. The aim was to determine the state of research in this area of science, and determine if a review of the literature might permit a gross generalization as to whether the combined effects of multi-stressors and radiation are fundamentally additive, synergistic or antagonistic. A multiple stressor database was established for different organism groups. Information was collected on species, stressors applied and effects evaluated. Studies were mostly laboratory based and investigated two-component mixtures. Interactions declared positive occurred in 58% of the studies, while 26% found negative interactions. Interactions were dependent on dose/concentration, on organism's life stage and exposure time and differed among endpoints. Except for one study, none of the studies predicted combined effects following Concentration Addition or Independent Action, and hence, no justified conclusions can be made about synergism or antagonism. - This review on multiple stressor studies involving radiation, highlights that most experimental designs used did not allow to deduce the nature of the interactive effects.

  16. Dedicated Trigger for Highly Ionising Particles at ATLAS

    Katre, Akshay; The ATLAS collaboration

    2015-01-01

    In 2012, a novel strategy was designed to detect signatures of Highly Ionising Particles (HIPs) such as magnetic monopoles, dyons or Qballs with the ATLAS trigger system. With proton-proton collisions at a centre of mass enegy of 8 TeV, the trigger was designed to have unique properties as a tracker for HIPs. It uses only the Transition Radiation Tracker (TRT) system, applying an algorithm distinct from standard tracking ones. The unique high threshold readout capability of the TRT is used at the location where HIPs in the detector are looked for. In particular the number and the fraction of TRT high threshold hits is used to distinguish HIPs from background processes. The trigger requires significantly lower energy depositions in the electro-magnetic calorimeters as a seed unlike previously used trigger algorithms for such searches. Thus the new trigger is capable of probing a large range of HIP masses and charges. We will give a description of the algorithms for this newly developed trigger for HIP searches...

  17. The distribution of a pure beta-emitter in the human body. Problems and preliminary results of Bremsstrahlung measurements in vivo; La repartition d'un emetteur beta pur dans l'organisme humain. Problemes poses par les mesures in vivo du rayonnement de freinage et premiers resultats obtenus; Raspredelenie chistogo beta-izluchatel ya v chelovecheskom organizme Problemy i predvaritel'ny e rezul'taty izmerenij tormoznogo izlucheniya v zhivom organizme; Distribucion de un emisor beta puro en el organisme humano. Problemas planteados por las mediciones in vivo de la radiacion de frenado y resultados preliminares obtenidos

    Mehl, H G [Strahleninstitut der Freien Universitaet, Berlin (Germany)

    1959-07-01

    In vivo measurements of the distribution of a pure beta-emitter in the human body were previously limited to the localization of radioactivity in superficial tissues only, owing to the short range of the beta particles in tissue. During die last few years the analysis has been extended by means of bremsstrahlung measurements to activities in deep-lying tissues. The present paper deals with problems and results of this new technique. On the basis of an analysis of the physical nature of this radiation, the construction of suitable detection devices is discussed. The theoretical and experimental work done in this field are reviewed. In order to make a proper interpretation of the results obtained, it is necessary to analyse the various factors involved. These include particularly the area ''seen'' by the detector, the specific activity of the tissue seen and the depth of the organ under consideration, A discussion of the results of such measurements already published will permit an assessment of the present situation and of the nature of the problems still unsolved. (author) [French] Les mesures in vivo de la repartition d'un emetteur beta pur dans l'organisme humain se limitaient autrefois a la localisation de la radioactivite dans les tissus superficiels, en raison du faible parcours des particules beta dans l'organisme. Depuis quelques armees, il est possible, grace aux mesures du rayonnement de freinage, d'etudier egalement la radioactivite dans les tissus profonds. L'auteur examine les problemes poses par cette technique nouvelle et les resultats qu'elle permet d'obtenir. Il indique des procedes de detection fondes sur les caracteristiques physiques de ce rayonnement. Il decrit les recherches theoriques et experimentales qui ont ete faites dans ce domaine. Pour interpreter correctement les resultats obtenus, il importe d'analyser les differents facteurs qui interviennent, notamment la surface par le detecteur, l'activite specifique du tissu observe et

  18. Ionisation of hydrogen-like atoms by a multiphoton absorption process; Ionisation des atomes hydrogenoides par un processus d'absorption multiphotonique

    Gontier, Y; Trahin, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-07-01

    The general expression for the amplitude of the probability of ionisation by a multiphoton absorption process is derived. Its non-relativistic limit is taken and the bipolar approximation is used for calculating the ionisation cross-section of hydrogen-like atoms. This latter involves the summation over intermediate virtual states by means of: a) a recursion relationship concerning angular functions, b) a particular technique which when applied to radial functions makes it possible to solve a system of inhomogeneous first-order differential equations. (authors) [French] On etablit l'expression generale de l'amplitude de probabilite d'ionisation par un processus d'absorption multiphotonique. On en prend la limite non-relativiste et l'on utilise l'approximation dipolaire avant de calculer la section efficace d'ionisation d'atomes hydrogenoides. Cette derniere fait intervenir des sommations sur des etats virtuels intermediaires effectuees a l'aide: a) d'une relation de recurrence qui concerne les fonctions angulaires, b) d'une technique particuliere qui, appliquee aux fonctions radiales, conduit a resoudre un systeme d'equations differentielles inhomogenes du premier ordre. (auteur)

  19. Measurement of the electronic density of ionised media by hyper frequency methods; Mesure de la densite electronique des milieux ionises par des methodes hyperfrequences

    Consoli, T [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    Within the limits of the I.N.S.T.N. courses on plasmas, this analytical study summarizes the articles quoted in the references on hyper-frequency techniques for the measurement of electronic density of an ionised gas. It is neither exhaustive nor complete and further details may be obtained by referring to the works mentioned. The first part, devoted to the theoretical side, concert the propagation of electromagnetic waves ionised media and the excitation of stationary raves in electromagnetic cavities. The second part deals with the measurement techniques themselves. It includes those techniques which hare become classic, and also more recent ones being developed in various laboratories and in the Service of Applied Physics at Saclay. (author) [French] Dans le cadre des cours sur les plasmas a l'l.N.S.T. cette etude d'analyse resume les articles cites en bibliographie sur les techniques hyperfrequences pour la mesure de la densite electronique d'un gas ionise. Elle n'est ni exhaustive, ni complete. Pour plus de details on voudra bien se rapporter aux travaux mentionnes. La premiere partie consacree a des rappels theoriques, concerne la propagation des ondes electromagnetiques dans les milieux ionises et sur l'excitation d'ondes stationnaires dans les cavites electromagnetiques. La seconde se rapporte aux techniques de mesures proprement dites. On a fait figurer dans cette partie des techniques devenues classiques et celles plus recentes en cours d'etudes dans divers laboratoires et au Service de Physique Appliquee a SACLAY. (auteur)

  20. The Ionising Radiations Advisory Committee Open Meeting 10 October 2001

    NONE

    2001-12-01

    Full text: The Ionising Radiations Advisory Committee (IRAC) held its first open meeting on 10 October 2001 in response to a request from the Health and Safety Commission (HSC) that all its advisory committees should follow the Commission's example and hold such meetings. Some of the other advisory committees have already held open meetings and others are planning to do so shortly. The aim of the meeting was to enable members of the public to meet IRAC members and to find out more about the Committee - how it worked and the type of issues it dealt with. The first two sessions were devoted to short presentations describing IRAC's work and influences, now and in the future, on radiation protection generally. The third session was a discussion forum. The agenda for the meeting and the presentations are posted on the web at: www.hse.gov.uk/foi/iracopen.htm. Each session of presentations was followed by questions of clarification and the third session of the meeting comprised an open forum. Many of the questions raised were not directly relevant to IRAC but, nevertheless, members provided brief responses and referred questions on to others as appropriate. One question had been notified in advance, asking whether members of IRAC agreed that it is now (regrettably) reasonably foreseeable that a loss of containment of radioactive material may occur at a nuclear facility as a result of impact by an aeroplane or by other hostile acts, and that this should be made clear in published guidance on REPPIR. This question was not within IRAC's remit. The Chairman of the Nuclear Safety Advisory Committee offered to take the question to the Committee's next meeting. Issues discussed included: Concerns that exposure to ionising radiation at low levels is more dangerous than is currently reflected in risk estimates. The European Parliament has adopted a resolution calling on the main international bodies, including the International Commission on Radiological

  1. Impact ionisation mass spectrometry of polypyrrole-coated pyrrhotite microparticles

    Hillier, Jon K.; Sternovsky, Zoltan; Armes, Steven P.; Fielding, Lee A.; Postberg, Frank; Bugiel, Sebastian; Drake, Keith; Srama, Ralf; Kearsley, Anton T.; Trieloff, Mario

    2014-07-01

    Cation and anion impact ionization mass spectra of polypyrrole-coated pyrrhotite cosmic dust analogue particles are analysed over a range of cosmically relevant impact speeds. Spectra with mass resolutions of 150-300 were generated by hypervelocity impacts of charged particles, accelerated to up to 37 km s-1 in a Van de Graaff electrostatic accelerator, onto a silver target plate in the Large Area Mass Analyzer (LAMA) spectrometer. Ions clearly indicative of the polypyrrole overlayer are identified at masses of 93, 105, 117, 128 and 141 u. Organic species, predominantly derived from the thin (20 nm) polypyrrole layer on the surface of the particles, dominate the anion spectra even at high (>20 km s-1) impact velocities and contribute significantly to the cation spectra at velocities lower than this. Atomic species from the pyrrhotite core (Fe and S) are visible in all spectra at impact velocities above 6 km s-1 for 56Fe+, 9 km s-1 for 32S+ and 16 km s-1 for 32S- ions. Species from the pyrrhotite core are also frequently visible in cation spectra at impact speeds at which surface ionisation is believed to dominate (Silver was confirmed as an excellent choice for the target plate of an impact ionization mass spectrometer, as it provided a unique isotope signature for many target-projectile cluster peaks at masses above 107-109 u. The affinity of Ag towards a dominant organic fragment ion (CN-) derived from fragmentation of the polypyrrole component led to molecular cluster formation. This resulted in an enhanced sensitivity to a particular particle component, which may be of great use when investigating astrobiologically relevant chemicals, such as amino acids.

  2. The biological effects of exposure to ionising radiation

    Higson, D.J.

    2016-01-01

    Scenarios for exposure to ionising radiation range from natural background radiation (chronic) to the explosions of atomic bombs (acute), with some medical, industrial and research exposures lying between these extremes. Biological responses to radiation that predominate at high doses incurred at high dose rates are different from those that predominate at low doses and low dose rates. Single doses from bomb explosions ranged up to many thousand mGy. Acute doses greater than about 1000 mGy cause acute radiation syndrome (ARS). Below this threshold, radiation has a variety of potential latent health effects: Change to the incidence of cancer is the most usual subject of attention but change to longevity may be the best overall measure because decreased incidences of non-cancer mortality have been observed to coincide with increased incidence of cancer mortality. Acute doses greater than 500 mGy cause increased risks of cancer and decreased life expectancy. For doses less than 100 mGy, beneficial overall health effects ('radiation hormesis') have been observed. At the other end of the spectrum, chronic exposure to natural radiation has occurred throughout evolution and is necessary for the normal life and health of current species. Dose rates greater than the present global average of about 2 mGy per year have either no discernible health effect or beneficial health effects up to several hundred mGy per year. It is clearly not credible that a single health effects model -- such as the linear no-threshold (LNT) model of risk estimation -- could fit all latent health effects. A more realistic model is suggested.

  3. Protection of the environment from ionising radiation: IUR's perspective

    Strand, P.; Brown, J. E.; Iospje, M.

    2004-01-01

    Sufficient information currently exists to introduce an overall framework for the protection of the environment from ionising radiation, drawing upon the large amount of radiobiological and radioecological information that has been gathered over the preceding decades. Nevertheless, there is a requirement to address numerous knowledge gaps and to improve upon existing databases. After the first presentation of a framework for the protection of the environment in 1999/2000 by the IUR, there has been activity to collate information and develop methodologies. This has allowed numerous recommendations to be made concerning future system development.. Although the transfer of radionuclides is quite well known within some food-chains, there are very few data on the behaviour of radionuclides in non-temperate zones and on uptake to species that do not form part of the human food chain. There is a need to develop both transfer models (flux, dynamic, ecosystem, etc.) and genotoxicological bio monitoring techniques that are capable of allowing impact assessments at a variety of species, population and ecosystem levels and that could also deal with other environmental stressors. Knowledge of the doses and effects of background radiation is lacking, as are dose-effect relationships, including information on RBE for a variety of species, doses and dose rates. The importance of various components of an environmental impact assessment can be explored, through the application of sensitivity and uncertainty analyses. An example of this type of analysis, for a marine system, demonstrated the importance of several radioecological parameters in the derivation of dose rates. However, although such examples provide insight, caution should be practiced in their interpretation. It is therefore suggested that further analyses are conducted in order to provide more robust priority lists for resource allocation. The recommendations made in this paper emphasize the need for further focussed

  4. The ionisation parameter of star-forming galaxies evolves with the specific star formation rate

    Kaasinen, Melanie; Kewley, Lisa; Bian, Fuyan; Groves, Brent; Kashino, Daichi; Silverman, John; Kartaltepe, Jeyhan

    2018-04-01

    We investigate the evolution of the ionisation parameter of star-forming galaxies using a high-redshift (z ˜ 1.5) sample from the FMOS-COSMOS survey and matched low-redshift samples from the Sloan Digital Sky Survey. By constructing samples of low-redshift galaxies for which the stellar mass (M*), star formation rate (SFR) and specific star formation rate (sSFR) are matched to the high-redshift sample we remove the effects of an evolution in these properties. We also account for the effect of metallicity by jointly constraining the metallicity and ionisation parameter of each sample. We find an evolution in the ionisation parameter for main-sequence, star-forming galaxies and show that this evolution is driven by the evolution of sSFR. By analysing the matched samples as well as a larger sample of z physically consistent with the definition of the ionisation parameter, a measure of the hydrogen ionising photon flux relative to the number density of hydrogen atoms.

  5. Calibration of ARI QC ionisation chambers using the Australian secondary standards for activity

    Mo, L.; Van Der Gaast, H.A.; Alexiev, D.; Butcher, K.S.A.; Davies, J.

    1999-01-01

    The Secondary Standard Activity Laboratory (SSAL) in ANSTO routinely provides standardised radioactive sources, traceable activity measurements and custom source preparation services to customers. The most important activity carried out is the calibration of ionisation chambers located in the Quality Control (QC) section of Australian Radioisotopes (ARI). This ensures that their activity measurements are traceable to the Australian primary methods of standardisation. ARI QC ionisation chambers are calibrated for 99m Tc, 67 Ga, 131 I, 201 Tl and 153 Sm. The SSAL has a TPA ionisation chamber, which has been directly calibrated against a primary standard for a variety of radioactive nuclides. Calibration factors for this chamber were determined specifically for the actual volumes (5ml for 99m Tc, 131 I, 2ml for 67 Ga, 201 Tl and 3 ml for 153 Sm) and types of vial (Wheaton) which are routinely used at ARI. These calibration factors can be used to accurately measure the activity of samples prepared by ARI. The samples can subsequently be used to calibrate the QC ionisation chambers. QC ionisation chambers are re-calibrated biannually

  6. Scientific colloquium on medical supervision of workers exposed to ionizing and non ionizing radiations[Wissenschaftliches Kolloquium ueber die medizinische ueberwachung von arbeitern, die ionisierenden und nicht-ionisierenden strahlungen ausgesetzt sind]; Colloque scientifique sur la surveillance medicale des travailleurs exposes aux rayonnements ionisants et non ionisants. Wissenschaftliches Kolloquium ueber die medizinische Ueberwachung von Arbeiten, die ionisierenden und nicht-ionisierenden Strahlungen ausgesetzt sind

    NONE

    1975-07-01

    The general principles of medical surveillance for workers exposed to ionizing radiation were defined in the Euratom Basic Standards in 1959. These principles, which are in accordance with the early IGRP publications, have been adopted by the national authorities and implemented without difficulty. However, because of the forthcoming publication of the revised Basic Standards- in accordance with recent IGRP recommendations, the Commission decided to organize a meeting of doctors responsible for the medical surveillance of workers exposed to ionizing radiation in order to disseminate as widely as possible the results of experience gained in the field of radiological protection and to pinpoint the practical difficulties which might arise when the principles were applied. The Commission also considered it important to inform doctors specializing in radiological protection about the principles to be followed by those responsible for the health protection of workers exposed to non-ionizing radiation, particularly microwaves and Laser beams. The complete text of each report in the original language is given in this volume.

  7. Experimental study of the effect of an electric field on thermal exchanges under forced convection with gaseous carbon anhydride in presence of the radiation of the Melusine pile; Etude experimentale de l'effet d'un champ electrique sur les echanges thermiques en convection forcee avec l'anhydride carbonique gazeux en presence du rayonnement de la pile Melusine

    Perroud, P.; Rebiere, J.; Verdier, J.

    1961-01-21

    Previous studies showed that, under free or forced convection, the application of a non-uniform electric field with a sufficient intensity at the neighbourhood of the heating elements resulted in a significant improvement of the thermal exchange coefficient under some flow rate and pressure conditions. But these improvements first required the creation of ions in the gas (shock ionization and existence of a corona effect above a sufficient voltage). This document therefore report further studies performed at the neighbourhood of the Melusine atomic pile which would provide ionizing radiations of much greater intensity. The objectives were, on the one hand, a global verification of work hypotheses imagined for the exchange improvement mechanism, and, on the other hand, to obtain data on the conditions under which this exchange improvement mechanism could be used in channels of a reactor. The authors present the instrumentation (measurement cells, gas circuit, heating circuit, high voltage circuit), describe how physical values are measured (pressure, gas flow rate, temperature of the heating element, gas temperature, high voltage). They describe how they compare powers exchanged under forced convection between dioxide carbon and a heated wire with or without external ionizing radiations, and report the various performed calculations (power supplied to the gas, temperature shift, Nusselt and Reynolds numbers). They report and discuss experimental results obtained outside the pile without ionizing radiations, and within the pile in presence of a ionizing radiation [French] Les essais ont ete effectues dans les conditions suivantes: nombres de Reynolds variant de 20.000 a 80.000, pression de 11 a 21 kg/cm{sup 2}, temperatures moyennes de l'element chauffant de 200 a 600 deg. C, tension electrique de 0 a 30 kV eff et intensite maximum du rayonnement γ, 3x10{sup 7} roentgen/h. On a confirme, hors pile, que l'augmentation de la puissance echangee, au dessus du seuil d'ionisation

  8. The biological effects of ionising radiation on Crustaceans: A review

    Fuller, Neil; Lerebours, Adélaïde; Smith, Jim T.; Ford, Alex T.

    2015-01-01

    Highlights: • We comprehensively review the effects of ionising radiation in crustaceans. • Current environmental radioprotection levels found to be inadequate in some cases. • Mutation is shown to be a sensitive endpoint of radiation exposure. • Lowest observed effect dose rate varies by orders of magnitude. - Abstract: Historic approaches to radiation protection are founded on the conjecture that measures to safeguard humans are adequate to protect non-human organisms. This view is disparate with other toxicants wherein well-developed frameworks exist to minimise exposure of biota. Significant data gaps for many organisms, coupled with high profile nuclear incidents such as Chernobyl and Fukushima, have prompted the re-evaluation of our approach toward environmental radioprotection. Elucidating the impacts of radiation on biota has been identified as priority area for future research within both scientific and regulatory communities. The crustaceans are ubiquitous in aquatic ecosystems, comprising greater than 66,000 species of ecological and commercial importance. This paper aims to assess the available literature of radiation-induced effects within this subphylum and identify knowledge gaps. A literature search was conducted pertaining to radiation effects on four endpoints as stipulated by a number of regulatory bodies: mortality, morbidity, reproduction and mutation. A major finding of this review was the paucity of data regarding the effects of environmentally relevant radiation doses on crustacean biology. Extremely few studies utilising chronic exposure durations or wild populations were found across all four endpoints. The dose levels at which effects occur was found to vary by orders of magnitude thus presenting difficulties in developing phyla-specific benchmark values and reference levels for radioprotection. Based on the limited data, mutation was found to be the most sensitive endpoint of radiation exposure, with mortality the least sensitive

  9. The biological effects of ionising radiation on Crustaceans: A review

    Fuller, Neil; Lerebours, Adélaïde [Institute of Marine Sciences, School of Biological Sciences, University of Portsmouth, Ferry Road, Portsmouth, Hampshire PO4 9LY (United Kingdom); Smith, Jim T. [School of Earth & Environmental Sciences, University of Portsmouth, Burnaby Building, Burnaby Road, Portsmouth, Hampshire PO1 3QL (United Kingdom); Ford, Alex T., E-mail: alex.ford@port.ac.uk [Institute of Marine Sciences, School of Biological Sciences, University of Portsmouth, Ferry Road, Portsmouth, Hampshire PO4 9LY (United Kingdom)

    2015-10-15

    Highlights: • We comprehensively review the effects of ionising radiation in crustaceans. • Current environmental radioprotection levels found to be inadequate in some cases. • Mutation is shown to be a sensitive endpoint of radiation exposure. • Lowest observed effect dose rate varies by orders of magnitude. - Abstract: Historic approaches to radiation protection are founded on the conjecture that measures to safeguard humans are adequate to protect non-human organisms. This view is disparate with other toxicants wherein well-developed frameworks exist to minimise exposure of biota. Significant data gaps for many organisms, coupled with high profile nuclear incidents such as Chernobyl and Fukushima, have prompted the re-evaluation of our approach toward environmental radioprotection. Elucidating the impacts of radiation on biota has been identified as priority area for future research within both scientific and regulatory communities. The crustaceans are ubiquitous in aquatic ecosystems, comprising greater than 66,000 species of ecological and commercial importance. This paper aims to assess the available literature of radiation-induced effects within this subphylum and identify knowledge gaps. A literature search was conducted pertaining to radiation effects on four endpoints as stipulated by a number of regulatory bodies: mortality, morbidity, reproduction and mutation. A major finding of this review was the paucity of data regarding the effects of environmentally relevant radiation doses on crustacean biology. Extremely few studies utilising chronic exposure durations or wild populations were found across all four endpoints. The dose levels at which effects occur was found to vary by orders of magnitude thus presenting difficulties in developing phyla-specific benchmark values and reference levels for radioprotection. Based on the limited data, mutation was found to be the most sensitive endpoint of radiation exposure, with mortality the least sensitive

  10. Single-stage accelerator mass spectrometer radiocarbon-interference identification and positive-ionisation characterisation

    Wilcken, K.M., E-mail: klaus.wilcken@ansto.gov.au [Scottish Universities Environmental Research Centre, Scottish Enterprise Technology Park, East Kilbride G75 0QF (United Kingdom); Freeman, S.P.H.T.; Xu, S.; Dougans, A. [Scottish Universities Environmental Research Centre, Scottish Enterprise Technology Park, East Kilbride G75 0QF (United Kingdom)

    2013-01-15

    A single-stage accelerator mass spectrometer (SSAMS) is a good alternative to conventional spectrometers based on tandem electrostatic acceleration for radiocarbon measurement and permits experimentation with both negative and positive carbon ions. However, such {sup 14}C AMS of either polarity ions is limited by an interference. In the case of anion acceleration we have newly determined this to be summed {sup 13}C and {sup 16}O by improvising an additional Wien filter on our SSAMS deck. Also, {sup 14}C AMS might be improved by removing its dependency on negative-ionisation in a sputter ion source. This requires negative-ionisation of sample atoms elsewhere to suppress the {sup 14}N interference, which we accomplish by transmitting initially positive ions through a thin membrane. The ionisation dependence on ion-energy is found to be consistent with previous experimentation with vapours and thicker foils.

  11. The significance of a new correspondence principle for electromagnetic interaction in strong optical field ionisation

    Boreham, B. W.; Hora, H.

    1997-01-01

    We have recently developed a correspondence principle for electromagnetic interaction. When applied to laser interactions with electrons this correspondence principle identifies a critical laser intensity I*. This critical intensity is a transition intensity separating classical mechanical and quantum mechanical interaction regimes. In this paper we discuss the further application of I* to the interaction of bound electrons in atoms. By comparing I* with the ionisation threshold intensities as calculated from a cycle-averaged simple-atom model we conclude that I* can be usefully interpreted as a lower bound to the classical regime in studies of ionisation of gas atoms by intense laser beams

  12. Ionisation of hydrogen-like atoms by a multiphoton absorption process

    Gontier, Y.; Trahin, M.

    1967-01-01

    The general expression for the amplitude of the probability of ionisation by a multiphoton absorption process is derived. Its non-relativistic limit is taken and the bipolar approximation is used for calculating the ionisation cross-section of hydrogen-like atoms. This latter involves the summation over intermediate virtual states by means of: a) a recursion relationship concerning angular functions, b) a particular technique which when applied to radial functions makes it possible to solve a system of inhomogeneous first-order differential equations. (authors) [fr

  13. Properties of an electret ionisation chamber for individual dosimetry in photon radiation fields

    Doerschel, B.; Pretzsch, G.

    1985-01-01

    The main properties of individual photon dosemeters are their energy and angular dependence and their measuring range and measurement accuracy. The determination of radiation exposure from the dosemeter readout is based on the choice of appropriate conversion factors, taking into account the influence of body backscatter on the dosemeter readout. The measurement range and accuracy of an electret ionisation chamber primarily depend on the electret stability and charge state measurement as well as on the chamber geometry. Dosimetric properties are described for an electret ionisation chamber designed for personnel monitoring. (author)

  14. Dynamics of ionisation and entanglement in the 'atom + quantum electromagnetic field' system

    Sharapova, P R; Tikhonova, O V [Department of Physics, M.V. Lomonosov Moscow State University (Russian Federation)

    2012-03-31

    The dynamics of a model Rydberg atom in a strong nonclassical electromagnetic field is investigated. The field-induced transitions to the continuum involving different numbers of photons (with intermediate states in the discrete spectrum) are taken into account and the specific features of ionisation in 'squeezed' field states are considered in comparison with the case of classical light. A significant decrease in the ionisation rate is found, which is caused by the interference stabilisation of the atomic system. The entanglement of the atomic and field subsystems, the temporal dynamics of the correlations found, and the possibility of measuring them are analysed.

  15. Serum ionised calcium and cardiovascular disease in 45-years old men and women followed for 18 years

    Ogard, Christina Gerlach; Petersen, Janne; Jørgensen, Torben

    2006-01-01

    ) and a broader definition of CVD. Persons with ionised serum calcium in the highest quintile were compared with persons in the lower four quintiles. Results: In a univariate analysis persons with ionised serum calcium in the highest quintile had increased risk of IHD (p=0.001) and CVD (p=0.02) compared...

  16. The ionising radiation (medical exposure) regulations - IR (ME) R, Malta

    Desai, R.; Brejza, P.; Cremona, J.

    2004-01-01

    Full text: The regulations in Malta at present are in draft stage. These regulations partially implement European Council Directive 97/43/Euratom. This Directive lays down the basic measurements for the health and protection of individuals against dangers of ionising radiation in relation to medical exposure. The regulations impose duties on persons administering radiations, to protect people from unnecessary exposure whether as part of their own medical diagnosis, treatment or as part of occupational health worker for health screening, medico-legal procedures, voluntary participation in research etc. These regulations also apply to individuals who help other individuals undergoing medical exposure. Main provisions 1. Regulation 2 contains the definitions of 28 terms used in these regulations. 2. Regulation 3.1 and 3.2 sets out the medical exposures to which the regulations apply. 3. Regulation 4 requires approval of medical exposures due to medical research, from radiation protection board of Malta. 4. Regulation 5 prohibits new procedures involving medical exposure unless it has been justified in advance. 5. Regulation 6 provides conditions justifying medical exposures. It prohibits any medical exposure from being carried out which has not been justified and authorized and sets out matters to be taken into account for justification. 6. Regulation 7 requires that practitioner justifies the exposure, shall pay special attention towards (a) exposure from medical research procedures where there is no direct health benefit to the individual undergoing exposure, (b) exposures for medico-legal purposes; (c) exposures to pregnant or possible pregnant women and (d) exposures to breast-feeding women. 7. Regulation 8.1 to 8.3 prohibit any medical exposure from being carried out which has not been justified and sets out matters to be taken for justification 8. Regulation 8.4 prohibits an exposure if it cannot be justified. 9. Regulation 9 requires the employer to provide a

  17. Ionised media and fractures: application to cartilaginous tissues and oil industry

    Huyghe, J.M.R.J.; Kraaijeveld, F.; Remmers, J.J.C.; Borst, de R.; Denier, J; Finn, M.D.; Mattner, T

    2008-01-01

    ionized media are ubiquitous in nature. Our body holds onto water through ionised macromolecules that bind water up to a 1000 times their own mass. Clays and shales do a similar trick in the geoworld. Localization of deformation and fractures are very common. Bore hole instability through fracture

  18. Calculated ionisation potentials to determine the oxidation of vanillin precursors by lignin peroxidase.

    Have, ten R.; Rietjens, I.M.C.M.; Hartmans, S.; Swarts, H.J.; Field, J.A.

    1998-01-01

    In view of the biocatalytic production of vanillin, this research focused on the lignin peroxidase (LiP) catalysed oxidation of naturally occurring phenolic derivatives: O-methyl ethers, O-acetyl esters, and O-glucosyl ethers. The ionisation potential (IP) of a series of model compounds was

  19. Bioaerosol detection by aerosol TOF-mass spectrometry: Application of matrix assisted laser desorption/ionisation

    Wuijckhuijse, A.L. van; Stowers, M.A.; Kientz, Ch.E.; Marijnissen, J.C.M.; Scarlett, B.

    2000-01-01

    In previous publications the use of an aerosol time of flight mass spectrometer was reported for the on-line measurements of aerosols (Weiss 1997, Kievit 1995). The apparatus is capable of measuring the size as well as the chemical composition, by the use of Laser Desorption/Ionisation (LDI), of an

  20. International responsability of state by the deleterius effects of ionising radiation

    Faria, N.M. de.

    1988-01-01

    International Responsability of State, considering the deleterius effects of ionising radiation on the human being, property, territory and environment which are under other jurisdiction, is focused. Conventional rules, costumary rules, the evolution of ''opinion juris'' as well as the decisions of tribunals related to the subject are analysed. (author) [pt

  1. S.I. No 125 of 2000 Radiological Protection Act 1991 (ionising radiation) Order 2000

    2000-01-01

    This statutory instrument provides for the implementation of Council Directive 96/29/Euratom of 13 May 1996 laying down basic safety standards for the protection of the health of workers and the general public against the dangers arising from ionising radiation. It also incorporates the provisions of Council Directive 90/641/Euratom of 4 December 1990 on the operational protection of outside workers exposed to the risk of ionising radiation during their activities in controlled areas. It replaces the provisions of the European Communities (Ionising Radiation) Regulations, 1991 (S.I. No. 43 of 1991), the Radiological Protection Act, 1991 (General Control of Radioactive Substances, Nuclear Devices and Irradiating Apparatus) Order, 1993 (S.I. No. 151 of 1993) and the European Communities (Protection of Outside Workers from Ionising Radiation) Regulations, 1994 (S.I. No. 144 of 1994). The main changes introduced in this Order are: the inclusion of work activities involving exposure to natural sources of radiation, stricter application of existing radiation protection principles through the introduction of lower dose limits, the use of dose constraints in keeping doses as low as reasonably achievable (i.e. optimisation process) and extended application of justification principles, the introduction of radiation protection principles for intervention in cases of radiological emergencies or lasting exposures. (author)

  2. Coupled-states calculations of argon L-shell impact ionisation

    Martir, M.H.; Ford, A.L.; Reading, J.F.

    1982-01-01

    A coupled-states method is used to calculate the corrections to the first Born approximation for L-shell impact ionisation in the ion-atom collisions p+Ar and α+Ar at energies between 100 and 850 keV amu -1 . Using a classical projectile path and a pseudostate description of the ionisation continuum, the pseudostate and partial-wave convergence is considered. It is found that the absolute cross sections for these collisions are sensitive to the particular independent-particle-model (IPM) target-atom potential which is used. A modification to the long-range part of the neutral-atom Hartree-Fock (HF) potential is proposed that lowers the energy of the unbound pseudostates and that thereby brings the L-shell removal energies closer to the experimental ionisation potentials. With this modified HF potential good agreement between the present L-shell ionisation cross sections and experimental L-vacancy production cross sections is found. (author)

  3. Study and optimization of the ionisation channel in the Edelweiss dark matter direct detection experiment

    Censier, B.

    2006-02-01

    The EDELWEISS experiment is aiming at the detection of Weakly Interactive Massive Particles (WIMPs), today's most favoured candidates for solving the dark matter issue. Background ionising particles are identified thanks to the simultaneous measurement of heat and ionisation in the detectors. The main limitation to this method is coming from the ionisation measurement, charge collection being less efficient in some part of the detectors known as 'dead' areas. The specificity of the measurement is due to the use of very low temperatures and low collection fields. This thesis is dedicated to the study of carrier trapping. It involves time-resolved charge measurements as well as a simulation code adapted to the specific physical conditions. We first present results concerning charge trapping at the free surfaces of the detectors. Our method allows to build a surface-charge in a controlled manner by irradiation with a strong radioactive source. This charge is then characterised with a weaker source which acts as a probe. In a second part of the work, bulk-trapping characteristics are deduced from charge collection efficiency measurements, and by an original method based on event localisation in the detector. The results show that a large proportion of the doping impurities are ionised, as indicated independently by the study of degradation by space-charge build-up. In this last part, near-electrodes areas are found to contain large densities of charged trapping centres, in connection with dead-layer effects. (author)

  4. Chapter 8. Ionisation radiation and human organism. Radioactivity of human tissues

    Toelgyessy, J.; Harangozo, M.

    2000-01-01

    This is a chapter of textbook of radioecology for university students. In this chapter authors deal with ionisation radiation and human organism as well as with radioactivity of human tissues. Chapter consists of next parts: (1) Radiation stress of human organism; (2) Radioactivity of human tissues and the factors influencing radioactive contamination; (3) Possibilities of decreasing of radiation stress

  5. Exploring Learners' Conceptual Resources: Singapore a Level Students' Explanations in the Topic of Ionisation Energy

    Taber, Keith S.; Tan, Kim Chwee Daniel

    2007-01-01

    This paper describes findings from a study to explore Singapore A-level (Grades 11 and 12, 16-19 yr old) students' understanding of ionisation energy, an abstract and complex topic that is featured in school chemistry courses. Previous research had reported that students in the United Kingdom commonly use alternative notions based on the perceived…

  6. Student and intern awareness of ionising radiation exposure from common diagnostic imaging procedures

    Zhou, G. Z.; Wong, D. D.; Nguyen, L. K.; Mendelson, R. M.

    2010-01-01

    Full text: This study aims to evaluate medical student and intern awareness of ionising radiation exposure from common diagnostic imaging procedures and to suggest how education could be improved. Fourth to sixth year medical students enrolled at a Western Australian university and interns from three teaching hospitals in Perth were recruited. Participants were asked to complete a questionnaire consisting of 26 questions on their background, knowledge of ionising radiation doses and learning preferences for future teaching on this subject. A total of 331 completed questionnaires were received (95.9%). Of the 17 questions assessing knowledge of ionising radiation, a mean score of 6.0 was obtained by respondents (95% CI 5.8-6.2). Up to 54.8% of respondents underestimated the radiation dose from commonly requested radiological procedures. Respondents (11.3 and 25.5%) incorrectly believed that ultrasound and MRI emit ionising radiation, respectively. Of the four subgroups of respondents, the intern doctor subgroup performed significantly better (mean score 6.9, P< 0.0001, 95% CI 6.5-7.3) than each of the three medical student subgroups. When asked for the preferred method of teaching for future radiation awareness, a combination of lectures, tutorials and workshops was preferred. This study has clearly shown that awareness of ionising radiation from diagnostic imaging is lacking among senior medical students and interns. The results highlight the need for improved education to minimise unnecessary exposure of patients and the community to radiation. Further studies are required to determine the most effective form of education.

  7. Destruction of Raman biosignatures by ionising radiation and the implications for life detection on Mars.

    Dartnell, Lewis R; Page, Kristian; Jorge-Villar, Susana E; Wright, Gary; Munshi, Tasnim; Scowen, Ian J; Ward, John M; Edwards, Howell G M

    2012-04-01

    Raman spectroscopy has proven to be a very effective approach for the detection of microorganisms colonising hostile environments on Earth. The ExoMars rover, due for launch in 2018, will carry a Raman laser spectrometer to analyse samples of the martian subsurface collected by the probe's 2-m drill in a search for similar biosignatures. The martian surface is unprotected from the flux of cosmic rays, an ionising radiation field that will degrade organic molecules and so diminish and distort the detectable Raman signature of potential martian microbial life. This study employs Raman spectroscopy to analyse samples of two model organisms, the cyanobacterium Synechocystis sp. PCC 6803 and the extremely radiation resistant polyextremophile Deinococcus radiodurans, that have been exposed to increasing doses of ionising radiation. The three most prominent peaks in the Raman spectra are from cellular carotenoids: deinoxanthin in D. radiodurans and β-carotene in Synechocystis. The degradative effect of ionising radiation is clearly seen, with significant diminishment of carotenoid spectral peak heights after 15 kGy and complete erasure of Raman biosignatures by 150 kGy of ionising radiation. The Raman signal of carotenoid in D. radiodurans diminishes more rapidly than that of Synechocystis, believed to be due to deinoxanthin acting as a superior scavenger of radiolytically produced reactive oxygen species, and so being destroyed more quickly than the less efficient antioxidant β-carotene. This study highlights the necessity for further experimental work on the manner and rate of degradation of Raman biosignatures by ionising radiation, as this is of prime importance for the successful detection of microbial life in the martian near subsurface.

  8. Quantification of complex DNA damage by ionising radiation. An experimental and theoretical approach

    Fulford, J.

    2000-05-01

    Ionising radiation potentially produces a broad spectrum of damage in DNA including single and double strand breaks (ssb and dsb) and base damages. It has been hypothesised that sites of complex damage within cellular DNA have particular biological significance due to an associated decreased efficiency in repair. The aim of this study is to gain further understanding of the formation of complex DNA damage. Irradiations of plasmid DNA illustrate that an increase in ionising density of the radiation results in a decrease in ssb yields/Gy but an increase in dsb per ssb, indicative of an increase in the number of complex damage sites per simple isolated damage site. As the mechanism for damage formation shifts from purely indirect at low scavenging capacities to a significant proportion of direct at higher scavenging capacities the proportion of complex damage increases. Comparisons with the yields of ssb and dsb simulated by Monte-Carlo calculations for Al K USX and α-particles also indicate this correspondence. The ionisation density of low energy, secondary electrons produced by photons was assessed experimentally from the dependence of the yield of OH radicals escaping intra-track recombination on photon energy. As energy decreases the OH radical yield initially decreases reflecting an increased ionisation density. However, with further decrease in photon energy the yield of OH radicals increases in line with theoretical calculations. Base damage yields were determined for low and high ionising density radiation over a range of scavenging capacities. As scavenging capacity increases the base damage: ssb ratios increases implying a contribution from electrons to base damage. It is proposed that base damage contributes to DNA damage complexity. Complex damage analysis reveals that at cell mimetic scavenging capacities, 23% and 72% of ssb have an additional spatially close damage site following γ-ray and α-particle irradiation respectively. (author)

  9. Properties of an ionised-cluster beam from a vaporised-cluster ion source

    Takagi, T.; Yamada, I.; Sasaki, A.

    1978-01-01

    A new type of ion source vaporised-metal cluster ion source, has been developed for deposition and epitaxy. A cluster consisting of 10 2 to 10 3 atoms coupled loosely together is formed by adiabatic expansion ejecting the vapour of materials into a high-vacuum region through the nozzle of a heated crucible. The clusters are ionised by electron bombardment and accelerated with neutral clusters toward a substrate. In this paper, mechanisms of cluster formation experimental results of the cluster size (atoms/cluster) and its distribution, and characteristics of the cluster ion beams are reported. The size is calculated from the kinetic equation E = (1/2)mNVsub(ej) 2 , where E is the cluster beam energy, Vsub(ej) is the ejection velocity, m is the mass of atom and N is the cluster size. The energy and the velocity of the cluster are measured by an electrostatic 127 0 energy analyser and a rotating disc system, respectively. The cluster size obtained for Ag is about 5 x 10 2 to 2 x 10 3 atoms. The retarding potential method is used to confirm the results for Ag. The same dependence on cluster size for metals such as Ag, Cu and Pb has been obtained in previous experiments. In the cluster state the cluster ion beam is easily produced by electron bombardment. About 50% of ionised clusters are obtained under typical operation conditions, because of the large ionisation cross sections of the clusters. To obtain a uniform spatial distribution, the ionising electrode system is also discussed. The new techniques are termed ionised-cluster beam deposition (ICBD) and epitaxy (ICBE). (author)

  10. Ionising radiation risk disclosure: When should radiographers assume a duty to inform?

    Younger, C W E; Douglas, C; Warren-Forward, H

    2018-05-01

    Autonomy is a fundamental patient right for ethical practice, and informed consent is the mechanism by which health care professionals ensure this right has been respected. The ethical notion of informed consent has evolved alongside legal developments. Under Australian law, a provider who fails to disclose risk may be found to be in breach of a duty of disclosure, potentially facing legal consequences if the patient experiences harm that is attributable to an undisclosed risk. These consequences may include the common law tort of negligence. Ionising radiation, in the form of a medical imaging examination, has the potential to cause harm. However, stochastic effects cannot be attributable to a specific ionising radiation event. What then is the role of the Australian medical imaging service provider in disclosing ionising radiation risk? The ethical and legal principles of informed consent, and the duty of information provision to the patient are investigated. These general principles are then applied to the specific and unusual case of ionising radiation, and what responsibilities apply to the medical imaging provider. Finally, the legal, professional and ethical duties of the radiographer to disclose information to their patients are investigated. Australian law is unclear as to whether a radiographer has a common law responsibility to disclose radiation risk. There is ambiguity as to whether stochastic ionising radiation risk could be considered a legal disclosure responsibility. While it is unlikely that not disclosing risk will have medicolegal consequences, doing so represents sound ethical practice. Copyright © 2017 The College of Radiographers. Published by Elsevier Ltd. All rights reserved.

  11. A self-calibrating ionisation chamber for the precise intensity calibration of high-energy heavy-ion beam monitors

    Junghans, A.

    1996-01-01

    The intensity of a 136 Xe(600 A MeV) beam has been determined by simultaneously measuring the particle rate and the corresponding ionisation current with an ionisation chamber. The ionisation current of this self-calibrating device was compared at higher intensities with the current of a secondary-electron monitor and a calibration of the secondary-electron current was achieved with a precision of 2%. This method can be applied to all high-energy heavy-ion beams. (orig.)

  12. The effect of an alternating electric field on a totally ionised plasma; Action d'un champ electrique alternatif sur un plasma totalement ionise

    Baglin, H; Brin, A; Ozias, Y; Salmon, J [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires; Delcroix, J L [Ecole Normale Superieure, 75 - Paris (France)

    1960-07-01

    The equation giving the distribution function of the electrons in a steady-state, for a fully ionized plasma in an a.c. field, are provided from the Fokker-Planck equation. The electric conductivity is complex and depends on the frequency. (author) [French] L'equation qui donne la fonction de distribution des electrons dans un etat stationnaire pour un plasma totalement ionise dans un champ electrique alternatif est fournie par l'equation de Fokker-Planck. La conductibilite electrique est complexe et depend de la frequence. (auteur)

  13. European Communities (Foodstuffs treated with ionising radiation) Regulations, 2000. Statutory Instrument S.I. No. 297 of 2000

    2000-01-01

    These Regulations give effect to Directive 1999/2/EC (the framework Directive) of the European Parliament and of the Council of 22 February 1999 on the approximation of the laws of the Member States concerning foods and food ingredients treated with ionising radiation and Directive 1999/3/EC (the implementing Directive) of the European Parliament and of the Council of 22 February 1999 on the establishment of a Community list of foods and food ingredients treated with ionising radiation. The effect of these Regulations is to lay down the general provisions for the treatment of foodstuffs with ionising radiation. Provisions concerning the approval and control of irradiation facilities and rules on labelling are also included. A positive list of foodstuffs authorised for treatment with ionising radiation and their maximum radiation doses are defined in the implementing Directive. These Regulations should be read together with the two Directives (author)

  14. Comparison of quantification methods for the analysis of polychlorinated alkanes using electron capture negative ionisation mass spectrometry

    Rusina, T.; Korytar, P.; Boer, de J.

    2011-01-01

    Four quantification methods for short-chain chlorinated paraffins (SCCPs) or polychlorinated alkanes (PCAs) using gas chromatography electron capture negative ionisation low resolution mass spectrometry (GC-ECNI-LRMS) were investigated. The method based on visual comparison of congener group

  15. How do air ions reflect variations in ionising radiation in the lower atmosphere in a boreal forest?

    X. Chen

    2016-11-01

    Full Text Available Most of the ion production in the atmosphere is attributed to ionising radiation. In the lower atmosphere, ionising radiation consists mainly of the decay emissions of radon and its progeny, gamma radiation of the terrestrial origin as well as photons and elementary particles of cosmic radiation. These types of radiation produce ion pairs via the ionisation of nitrogen and oxygen as well as trace species in the atmosphere, the rate of which is defined as the ionising capacity. Larger air ions are produced out of the initial charge carriers by processes such as clustering or attachment to pre-existing aerosol particles. This study aimed (1 to identify the key factors responsible for the variability in ionising radiation and in the observed air ion concentrations, (2 to reveal the linkage between them and (3 to provide an in-depth analysis into the effects of ionising radiation on air ion formation, based on measurement data collected during 2003–2006 from a boreal forest site in southern Finland. In general, gamma radiation dominated the ion production in the lower atmosphere. Variations in the ionising capacity came from mixing layer dynamics, soil type and moisture content, meteorological conditions, long-distance transportation, snow cover attenuation and precipitation. Slightly similar diurnal patterns to variations in the ionising capacity were observed in air ion concentrations of the cluster size (0.8–1.7 nm in mobility diameters. However, features observed in the 0.8–1 nm ion concentration were in good connection to variations of the ionising capacity. Further, by carefully constraining perturbing variables, a strong dependency of the cluster ion concentration on the ionising capacity was identified, proving the functionality of ionising radiation in air ion production in the lower atmosphere. This relationship, however, was only clearly observed on new particle formation (NPF days, possibly indicating that charges after

  16. Search for ionisation density effects in the radiation absorption stage in LiF:Mg,Ti

    Nail, I.; Horowitz, Y. S.; Oster, L.; Brandan, M. E.; Rodriguez-Villafuerte, M.; Buenfil, A. E.; Ruiz-Trejo, C.; Gamboa-deBuen, I.; Avila, O.; Tovar, V. M.; Olko, P.; Ipe, N.

    2006-01-01

    Optical absorption (OA) dose-response of LiF:Mg,Ti (TLD-100) is studied as a function of electron energy (ionisation density) and irradiation dose. Contrary to the situation in thermoluminescence dose-response where the supra-linearity is strongly energy-dependent, no dependence of the OA dose filling constants on energy is observed. This result is interpreted as indicating a lack of competitive process in the radiation absorption stage. The lack of an energy dependence of the dose filling constant also suggests that the charge carrier migration distances are sufficiently large to smear out the differences in the non-uniform distribution of ionisation events created by the impinging gamma/ electron radiation of various energies. (authors)

  17. Exploring the Powerful Ionised Wind in the Seyfert Galaxy PG1211+143

    Pounds, Ken

    2013-10-01

    Highly-ionised high-speed winds in AGN (UFOs) were first detected with XMM-Newton a decade ago, and are now established as a key factor in the study of SMBH accretion, and in the growth and metal enrichment of their host galaxies. However, information on the ionisation and dynamical structure, and the ultimate fate of UFOs remains very limited. We request a 600ks extended XMM-Newton study of the prototype UFO PG1211+143 in AO-13, to obtain high quality EPIC and RGS spectra, to map the flow structure and variability, while seeking evidence for the anticipated interaction with the ISM and possible conversion of the energetic wind to a momentum-driven flow.

  18. Double ionisation of helium in fast ion collisions: the role of momentum transfer

    Bapat, B.; Moshammer, R.; Schmitt, W.; Kollmus, H.; Ullrich, J.; Doerner, R.; Weber, T.; Khayyat, K.

    1999-01-01

    Double ionisation of helium in the perturbative regime has been explored in a kinematically complete collision experiment using 100 MeV/u C 6+ ions. Different ionisation mechanisms are identified by inspecting the angular distribution of the electrons as a function of the momentum transfer q to the target by the projectile. For q 1.2 a.u., the faster electron resulting from a binary encounter with the projectile is emitted along the direction of momentum transfer, while the other electron is distributed uniformly. Experimental data are compared with various model calculations based on the Bethe-Born approximation with shake-off. Surprisingly, the effect of the final state interaction is found to depend decisively on the choice of the initial state wave function. (orig.)

  19. Non-targeted effects of ionising radiation—Implications for low dose risk

    Kadhim, Munira; Salomaa, Sisko; Wright, Eric

    2013-01-01

    and adaptive responses are powered by fundamental, but not clearly understood systems that maintain tissue homeostasis. Despite excellent research in this field by various groups, there are still gaps in our understanding of the likely mechanisms associated with non-DNA targeted effects, particularly......Non-DNA targeted effects of ionising radiation, which include genomic instability, and a variety of bystander effects including abscopal effects and bystander mediated adaptive response, have raised concerns about the magnitude of low-dose radiation risk. Genomic instability, bystander effects....... Furthermore, it is still not known what the initial target and early interactions in cells are that give rise to non-targeted responses in neighbouring or descendant cells. This paper provides a commentary on the current state of the field as a result of the non-targeted effects of ionising radiation (NOTE...

  20. Voxel anthropomorphic phantoms: review of models used for ionising radiation dosimetry

    Lemosquet, A.; Carlan, L. de; Clairand, I.

    2003-01-01

    Computational anthropomorphic phantoms have been used since the 1970's for dosimetric calculations. Realistic geometries are required for this operation, resulting in the development of ever more accurate phantoms. Voxel phantoms, consisting of a set of small-volume elements, appeared towards the end of the 1980's, and significantly improved on the original mathematical models. Voxel phantoms are models of the human body, obtained using computed tomography (CT) or magnetic resonance images (MRI). These phantoms are an extremely accurate representation of the human anatomy. This article provides a review of the literature available on the development of these phantoms and their applications in ionising radiation dosimetry. The bibliographical study has shown that there is a wide range of phantoms, covering various characteristics of the general population in terms of sex, age or morphology, and that they are used in applications relating to all aspects of ionising radiation. (author)

  1. Long term effects of low doses of ionising radiation: facts and fallacies

    Iyer, G.K.

    1993-01-01

    Health effects of low doses of ionising radiation have been a public concern. The public perception of these low effects is that it causes cancer and genetic effects. Enormous amount of work regarding this cancer has been done all over the world, on occupational workers exposed to low doses of ionising radiation. These studies do not show any adverse effect on them. Epidemiological studies done on members of public staying near nuclear facilities also have shown that there is no health risk involved in staying near these facilities. Genetic effects have also shown negative results. These two aspects of health effects of low dose of radiation are discussed in detail. (author). 5 refs., 1 tab

  2. Performance evaluation of synthetic diamond to realize ionisation chamber for radiotherapy application

    Guerrero Waryn, M.J.

    2005-09-01

    This work focuses on the optimisation of synthetic CVD diamond quality to realize ionisation chambers for radiotherapy. Diamonds samples have been synthesized and characterized using thermally stimulated measurement. These measurements showed the presence of trapping levels due to crystalline defects or impurities in material. The study of the response of these samples under irradiation has showed a correlation between the charged state of traps (priming and overshoot phenomena) and the response of the detector (stabilization of the signal). To remove the overshoot phenomenon which prevents from reproducible measurements, we used a specific operating set up controlling the device temperature. This technique enables to neutralize these instable phenomena and to use CVD diamond for ionisation chamber fabrication. (author)

  3. The Coulomb deflection effect on the L3-subshell alignment in low-velocity proton impact ionisation

    Palinkas, J.; Schlenk, B.; Valek, A.

    1981-01-01

    The alignment parameter of the L 3 subshell of gold has been determined by measuring the angular distribution of the Lsub(l)/Lsub(γ) intensity ratio following proton impact ionisation in the 0.25-0.60 MeV energy range. The experimental results make it clear that the minimum of the alignment parameter at low energies found earlier for He + impact also exists in the case of proton impact ionisation. (author)

  4. Determination of the ionisation potential of certain hydrocarbons in the liquid phase

    Casanovas, J.; Grob, R.; Brunet, G.; Sabattier, R.; Guelfucci, J.P.; Blanc, D.

    1978-01-01

    The first results obtained are presented on the determination of the ionisation potential of four alkanes (n-hexane, n-pentane, cyclopentane and trimethyl-2,2,4 pentane) in the liquid phase. In the gaseous phase, the ionisation potential values of these hydrocarbons are respectively 10.18 eV for n-hexane, 10.35 eV for n-pentane, 10.53 eV for cyclopentane and 9.86 eV for trimethyl-2,2,4 pentane. Consequently rare gas resonance lamps (krypton and Xenon) were made, sealed and excited by an ultra-high frequency wave, which emit photons in the energy field concerned, i.e. from 8.5 eV to 11eV. The energy of the photons emitted by these lamps is respectively 8.44 eV (100%) and 9.57 eV (2%) for xenon and 10.03 eV (100%) and 10.64 eV (5%) for krypton. From the extent of the induced ionisation currents and particularly the value of the ratio of the currents induced by the photons of the krypton and xenon lamps, a minimum value of the ionisation potential drop can be deduced compared with the gas phase of 0.61 eV for n-hexane, 0.78 eV for n-pentane, 0.96 eV for cyclopentane and a maximum value of 1.42 eV for trimethyl-2,2,4 pentane [fr

  5. International Atomic Energy Agency Regional Workshop on Commercialisation of ionising energy treatment of food: proceedings

    Wills, P.; Toner, B.

    1985-01-01

    The global need to ensure adequate food supplies places a demand on new technologies and techniques to improve yields and preservation of food by eliminating or reducing bacterial degradation and infestation of raw or processed foods. The use of ionising radiation in food processing also has potential to alleviate certain food-borne diseases which cause serious threats to the health of people in many countries

  6. Decontamination of hospital wastes by the combined action of ionising radiation and heat - the thermorad process

    Icre, P.; Rocquigny, H. de

    1995-01-01

    The Thermorad process is used for decontaminating hospital wastes at the hospital as they are collected from the different departments. The process utilises the combined microbiological effects of ionising radiation (5 kGy) and dry heat (60 o C). The treatment unit, which is compact and of small size, contains a cobalt 60 source of under 100,000 curies and has an annual treatment capacity of 5000 m 3 . (author)

  7. Analysis of oak tannins by liquid chromatography-electrospray ionisation mass spectrometry.

    Mämmelä, P; Savolainen, H; Lindroos, L; Kangas, J; Vartiainen, T

    2000-09-01

    Extractable tannins were analysed by liquid chromatography-electrospray ionisation mass spectrometry in two oak species, North American white oak (Quercus alba) and European red oak (Quercus robur). They mainly included various glucose gallic and ellagic acid esters. The structures were partially determined, and they included grandinin/roburin E, castalagin/vescalagin, gallic acid, valoneic acid bilactone, monogalloyl glucose, digalloyl glucose, trigalloyl glucose, ellagic acid rhamnose, quercitrin and ellagic acid.

  8. Experimental investigation of the utilisation of ionisation gauges for leak detection

    Benvenuti, C

    1972-01-01

    A description is given of a method of leak detecting applicable to the ISR (CERN) vacuum system after bakeout. This method, based on the enhanced indication of an ionisation gauge obtained when replacing the air around the leak by Argon, affords a detection efficiency not lower than that obtainable by means of a traditional leak detector; furthermore it does not introduce contamination risks after bakeout. (4 refs).

  9. Use of ionising radiation in the teaching of physics and chemistry

    2000-01-01

    The guide lays down the safety requirements for the use of radiation in school education, as well as the principles regulating the use of radiation sources without the safety licence referred to in section 16 of the Finnish Radiation Act (592/1991). The guide covers the use of radiation sources emitting ionising radiation in elementary schools and high schools, as well as the use of radiation in the teaching of physics and chemistry in vocational training institutions and corresponding educational institutions

  10. Guideline for the licensing of various designs of ionisation smoke alarms

    1978-01-01

    The purpose of the guideline is to set up criteria for the construction licensing of ionisation smoke alarms and to determine their use. This guarantees that only those ISA are licensed which correspond to the level of science and technology and that the ISA to be licensed fulfills the demands of radiation protection. The recommendations of OECD/NEA are also born in mind. (orig./HP) [de

  11. Absolute 3PO triple differential cross sections for electron-helium Wannier threshold ionisation

    Carruthers, D.R.J.; Crothers, D.S.F.

    1992-01-01

    The uniform semiclassical approximation of Crothers is employed to find a final-state 3 P O wave function for threshold electron impact ionisation of helium. The Kohn variational principle is applied perturbatively to evaluate the scattering amplitude and hence the absolute 3 P O contribution to the triple differential cross sections. These plus the previous absolute singlet results of Crothers are compared favourably with the relative experimental results of Selles et al. (orig.)

  12. Theoretical methods for the calculation of the multiphoton ionisation cross-section of atoms and molecules

    Moccia, R.

    1991-01-01

    Some of the available theoretical methods to compute the two-photon ionisation cross-section of many-electron systems are reviewed. In particular the problems concerning the computation of (i) reliable approximations for the transition matrix elements and the excitation energies; and (ii) accurate results pertaining to the electronic continuum by the use of L 2 basis functions are considered. (author). 29 refs., 6 figs., 1 tab

  13. Exposure of the French paediatric population to ionising radiation from diagnostic medical procedures in 2010

    Etard, Cecile; Aubert, Bernard; Mezzarobba, Myriam; Bernier, Marie-Odile

    2014-01-01

    Medical examination is the main source of artificial radiation exposure. Because children present an increased sensitivity to ionising radiation, radiology practices at a national level in paediatrics should be monitored. This study describes the ionising radiation exposure from diagnostic medical examinations of the French paediatric population in 2010. Data on frequency of examinations were provided by the French National Health Insurance through a representative sample including 107,627 children ages 0-15 years. Effective doses for each type of procedure were obtained from the published French literature. Median and mean effective doses were calculated for the studied population. About a third of the children were exposed to at least one examination using ionising radiation in 2010. Conventional radiology, dental exams, CT scans and nuclear medicine and interventional radiology represent respectively 55.3%, 42.3%, 2.1% and 0.3% of the procedures. Children 10-15 years old and babies from birth to 1 year are the most exposed populations, with respectively 1,098 and 734 examinations per 1,000 children per year. Before 1 year of age, chest and pelvis radiographs are the most common imaging tests, 54% and 32%, respectively. Only 1% of the studied population is exposed to CT scan, with 62% of these children exposed to a head-and-neck procedure. The annual median and mean effective doses were respectively 0.03 mSv and 0.7 mSv for the exposed children. This study gives updated reference data on French paediatric exposure to medical ionising radiation that can be used for public health or epidemiological purposes. Paediatric diagnostic use appears much lower than that of the whole French population as estimated in a previous study. (orig.)

  14. Ionising radiation and risk of death from leukaemia and lymphoma in radiation-monitored workers (INWORKS)

    Lorenz, Bernd

    2015-07-01

    Since July 2015 the study ''ionising radiation and risk of death from leukaemia and lymphoma in radiation-monitored workers (INWORKS) - an international cohort study'' is available. INWORKS comprised data from 300.000 occupational exposed and dosimetric monitored persons from France, USA and UK. The contribution is a critical discussion of this study with respect to the conclusion of a strong evidence of positive associations between protracted low-dose irradiation exposure and leukemia.

  15. Accuracy evaluation of the prescribed calibration factors for ionisation chambers belonging to radiotherapy centres

    Mohd Taufik Dolah; Supian Samat; Taiman Kadni

    1999-01-01

    Air kerma and exposure calibration factors of 14 ionisation chambers belonging to ten local radiotherapy centres have been determined by SSDL in the recent last ten month (1/10/1998 - 31/7/1999). The results obtained were compared either with previous SSDL results, or the chambers certificate values. The range of the percentage deviations obtained was -1.70% to 1.18%, which lies between the IAEA accepted value of range ±3.5%. (author)

  16. K-shell ionisation cross sections for W, Au and U by low velocity protons

    Castro Faria, N.V. de; Freire Junior, F.L.; Montenegro, E.C.; Pinho, A.G. de; Silveira, E.F. da.

    1984-01-01

    Proton-induced K-shell ionisation cross section for W, Au and U by low velocity protons were obtained from thick target measurements. For the first time the lowest incident energy reached a value less than 10 times the binding energy of the K-shell electron (less than 9 times in the case of Au). Possible errors are thoroughly examined and a comparison with other available experimental results and theoretical values is presented and discussed. (Author) [pt

  17. Full Ionisation In Binary-Binary Encounters With Small Positive Energies

    Sweatman, W. L.

    2006-08-01

    Interactions between binary stars and single stars and binary stars and other binary stars play a key role in the dynamics of a dense stellar system. Energy can be transferred between the internal dynamics of a binary and the larger scale dynamics of the interacting objects. Binaries can be destroyed and created by the interaction. In a binary-binary encounter, full ionisation occurs when both of the binary stars are destroyed in the interaction to create four single stars. This is only possible when the total energy of the system is positive. For very small energies the probability of this occurring is very low and it tends towards zero as the total energy tends towards zero. Here the case is considered for which all the stars have equal masses. An asymptotic power law is predicted relating the probability of full ionisation with the total energy when this latter quantity is small. The exponent, which is approximately 2.31, is compared with the results from numerical scattering experiments. The theoretical approach taken is similar to one used previously in the three-body problem. It makes use of the fact that the most dramatic changes in scale and energies of a few-body system occur when its components pass near to a central configuration. The position, and number, of these configurations is not known for the general four-body problem, however, with equal masses there are known to be exactly five different cases. Separate consideration and comparison of the properties of orbits close to each of these five central configurations enables the prediction of the form of the cross-section for full ionisation for the case of small positive total energy. This is the relation between total energy and the probability of total ionisation described above.

  18. The design of a calorimetric standard of ionising radiation absorbed dose

    Huntley, R.B.

    1981-05-01

    The design of a calorimetric working standard of ionising radiation absorbed dose is discussed. A brief history of the appropriate quantities and units of measurement is given. Detailed design considerations follow a summary of the relevant literature. The methods to be used to relate results to national standards of measurement are indicated, including the need for various correction factors. A status report is given on the construction and testing program

  19. An isotope view on ionising radiation as a source of sulphuric acid

    Enghoff, Martin Andreas Bødker; Bork, Nicolai Christian; Hattori, S.

    2012-01-01

    Sulphuric acid is an important factor in aerosol nucleation and growth. It has been shown that ions enhance the formation of sulphuric acid aerosols, but the exact mechanism has remained undetermined. Furthermore some studies have found a deficiency in the sulphuric acid budget, suggesting a miss...... yields of the experiments, suggests a mechanism in which ionising radiation may lead to hydrated ion clusters that serve as nanoreactors for S(IV) to S(VI) conversion....

  20. An isotopic analysis of ionising radiation as a source of sulphuric acid

    Enghoff, Martin Andreas Bødker; Bork, Nicolai Christian; Hattori, S.

    2012-01-01

    Sulphuric acid is an important factor in aerosol nucleation and growth. It has been shown that ions enhance the formation of sulphuric acid aerosols, but the exact mechanism has remained undetermined. Furthermore some studies have found a deficiency in the sulphuric acid budget, suggesting a miss...... of the experiments, suggests a mechanism in which ionising radiation may lead to hydrated ion clusters that serve as nanoreactors for S(IV) to S(VI) conversion....

  1. Exposure of the French paediatric population to ionising radiation from diagnostic medical procedures in 2010

    Etard, Cecile; Aubert, Bernard [Institut de Radioprotection et de Surete Nucleaire, Medical Expertise Unit, Fontenay-aux-Roses (France); Mezzarobba, Myriam [Institut de Radioprotection et de Surete Nucleaire, Laboratory of Epidemiology, Fontenay-aux-Roses (France); Bernier, Marie-Odile [Institut de Radioprotection et de Surete Nucleaire, Laboratory of Epidemiology, Fontenay-aux-Roses (France); Institut de Radioprotection et de Surete Nucleaire, IRSN/PRP-HOM/SRBE/LEPID, Laboratoire d' Epidemiologie, Fontenay-aux-Roses (France)

    2014-12-15

    Medical examination is the main source of artificial radiation exposure. Because children present an increased sensitivity to ionising radiation, radiology practices at a national level in paediatrics should be monitored. This study describes the ionising radiation exposure from diagnostic medical examinations of the French paediatric population in 2010. Data on frequency of examinations were provided by the French National Health Insurance through a representative sample including 107,627 children ages 0-15 years. Effective doses for each type of procedure were obtained from the published French literature. Median and mean effective doses were calculated for the studied population. About a third of the children were exposed to at least one examination using ionising radiation in 2010. Conventional radiology, dental exams, CT scans and nuclear medicine and interventional radiology represent respectively 55.3%, 42.3%, 2.1% and 0.3% of the procedures. Children 10-15 years old and babies from birth to 1 year are the most exposed populations, with respectively 1,098 and 734 examinations per 1,000 children per year. Before 1 year of age, chest and pelvis radiographs are the most common imaging tests, 54% and 32%, respectively. Only 1% of the studied population is exposed to CT scan, with 62% of these children exposed to a head-and-neck procedure. The annual median and mean effective doses were respectively 0.03 mSv and 0.7 mSv for the exposed children. This study gives updated reference data on French paediatric exposure to medical ionising radiation that can be used for public health or epidemiological purposes. Paediatric diagnostic use appears much lower than that of the whole French population as estimated in a previous study. (orig.)

  2. The philosophy and assumptions underlying exposure limits for ionising radiation, inorganic lead, asbestos and noise

    Akber, R.

    1996-01-01

    Full text: A review of the literature relating to exposure to, and exposure limits for, ionising radiation, inorganic lead, asbestos and noise was undertaken. The four hazards were chosen because they were insidious and ubiquitous, were potential hazards in both occupational and environmental settings and had early and late effects depending on dose and dose rate. For all four hazards, the effect of the hazard was enhanced by other exposures such as smoking or organic solvents. In the cases of inorganic lead and noise, there were documented health effects which affected a significant percentage of the exposed populations at or below the [effective] exposure limits. This was not the case for ionising radiation and asbestos. None of the exposure limits considered exposure to multiple mutagens/carcinogens in the calculation of risk. Ionising radiation was the only one of the hazards to have a model of all likely exposures, occupational, environmental and medical, as the basis for the exposure limits. The other three considered occupational exposure in isolation from environmental exposure. Inorganic lead and noise had economic considerations underlying the exposure limits and the exposure limits for asbestos were based on the current limit of detection. All four hazards had many variables associated with exposure, including idiosyncratic factors, that made modelling the risk very complex. The scientific idea of a time weighted average based on an eight hour day, and forty hour week on which the exposure limits for lead, asbestos and noise were based was underpinned by neither empirical evidence or scientific hypothesis. The methodology of the ACGIH in the setting of limits later brought into law, may have been unduly influenced by the industries most closely affected by those limits. Measuring exposure over part of an eight hour day and extrapolating to model exposure over the longer term is not the most effective way to model exposure. The statistical techniques used

  3. 1: the atom. 2: radioactivity. 3: man and radiations. 4: the energy. 5: nuclear energy: fusion and fission. 6: the operation of a nuclear reactor. 7: the nuclear fuel cycle; 1: l'atome. 2: la radioactivite. 3: l'homme et les rayonnements. 4: l'energie. 5: l'energie nucleaire: fusion et fission. 6: le fonctionnement d'un reacteur nucleaire. 7: le cycle du combustible nucleaire

    NONE

    2002-07-01

    This series of 7 digest booklets present the bases of the nuclear physics and of the nuclear energy: 1 - the atom (structure of matter, chemical elements and isotopes, the four fundamental interactions, nuclear physics); 2 - radioactivity (definition, origins of radioelements, applications of radioactivity); 3 - man and radiations (radiations diversity, biological effects, radioprotection, examples of radiation applications); 4 - energy (energy states, different forms of energy, characteristics); 5 - nuclear energy: fusion and fission (nuclear energy release, thermonuclear fusion, nuclear fission and chain reaction); 6 - operation of a nuclear reactor (nuclear fission, reactor components, reactor types); 7 - nuclear fuel cycle (nuclear fuel preparation, fuel consumption, reprocessing, wastes management). (J.S.)

  4. Evaluation of chromosomal aberrations in radiologists and medical radiographers chronically exposed to ionising radiation

    Kasuba, V.; Rozgaj, R.; Jazbec, A.

    2005-01-01

    Chromosomal aberrations are fairly reliable indicators of damage induced by ionising radiation. This study included 180 radiologists and medical radiographers (technicians) and 90 controls who were not occupationally exposed to ionising radiation. All exposed subjects were routinely monitored with film badge, and none was exposed to a radiation dose exceeding the limit for occupational exposure recommended by the International Commission on Radiological Protection (ICRP). Two hundred metaphases for each person were scored. The frequencies of acentric fragments, dicentrics, ring chromosomes and chromosomal exchanges were determined and compared to those obtained in the control group. Chromosome aberrations were analysed using Poisson regression for profession, age, sex, smoking and years of exposure. Age, smoking, diagnostic exposure to X-rays and occupation were found to correlate with the occurrence of acentric fragments. The influence of exposure duration on the frequency of acentric fragments was greater in medical radiographers than in radiologists. Smoking and sex were found to correlate with the occurrence of dicentric chromosomes, which were more common in men than in women. As chromosome aberrations exceeded the expected level with respect to the absorbed dose, our findings confirm the importance of chromosome analysis as a part of regular medical check-up of subjects occupationally exposed to ionising radiation.(author)

  5. Evaluation of cytogenetic damage in nuclear medicine personnel occupationally exposed to low-level ionising radiation

    Garaj-Vrhovac, V.; Kopjar, N.; Poropat, M.

    2005-01-01

    Despite intensive research over the last few decades, there still remains considerable uncertainty as to the genetic impact of ionising radiation on human populations, particularly at low levels. The aim of this study was to provide data on genetic hazards associated with occupational exposure to low doses of ionising radiation in nuclear medicine departments. The assessment of DNA damage in peripheral blood lymphocytes of medical staff was performed using the chromosome aberration (CA) test. Exposed subjects showed significantly higher frequencies of CA than controls. There were significant inter-individual differences in DNA damage within the exposed population, indicating differences in genome sensitivity. Age and gender were not confounding factors, while smoking enhanced the levels of DNA damage only in control subjects. The present study suggests that chronic exposure to low doses of ionising radiation in nuclear medicine departments causes genotoxic damage. Therefore, to avoid potential genotoxic effects, the exposed medical personnel should minimise radiation exposure wherever possible. Our results also point to the significance of biological indicators providing information about the actual risk to the radiation exposed individuals.(author)

  6. Nuclear recoil scintillation and ionisation yields in liquid xenon from ZEPLIN-III data

    Horn, M., E-mail: m.horn@imperial.ac.uk [High Energy Physics group, Blackett Laboratory, Imperial College London (United Kingdom); Belov, V.A.; Akimov, D.Yu. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Araujo, H.M. [High Energy Physics group, Blackett Laboratory, Imperial College London (United Kingdom); Barnes, E.J. [School of Physics and Astronomy, SUPA University of Edinburgh (United Kingdom); Burenkov, A.A. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Chepel, V. [LIP-Coimbra and Department of Physics of the University of Coimbra (Portugal); Currie, A. [High Energy Physics group, Blackett Laboratory, Imperial College London (United Kingdom); Edwards, B. [Particle Physics Department, STFC Rutherford Appleton Laboratory, Chilton (United Kingdom); Ghag, C.; Hollingsworth, A. [School of Physics and Astronomy, SUPA University of Edinburgh (United Kingdom); Kalmus, G.E. [Particle Physics Department, STFC Rutherford Appleton Laboratory, Chilton (United Kingdom); Kobyakin, A.S.; Kovalenko, A.G. [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Lebedenko, V.N. [High Energy Physics group, Blackett Laboratory, Imperial College London (United Kingdom); Lindote, A. [LIP-Coimbra and Department of Physics of the University of Coimbra (Portugal); Particle Physics Department, STFC Rutherford Appleton Laboratory, Chilton (United Kingdom); Lopes, M.I. [LIP-Coimbra and Department of Physics of the University of Coimbra (Portugal); Luescher, R.; Majewski, P. [Particle Physics Department, STFC Rutherford Appleton Laboratory, Chilton (United Kingdom); Murphy, A.StJ. [School of Physics and Astronomy, SUPA University of Edinburgh (United Kingdom)

    2011-11-24

    Scintillation and ionisation yields for nuclear recoils in liquid xenon above 10 keV{sub nr} (nuclear recoil energy) are deduced from data acquired using broadband Am-Be neutron sources. The nuclear recoil data from several exposures to two sources were compared to detailed simulations. Energy-dependent scintillation and ionisation yields giving acceptable fits to the data were derived. Efficiency and resolution effects are treated using a light collection Monte Carlo, measured photomultiplier response profiles and hardware trigger studies. A gradual fall in scintillation yield below {approx}40 keV{sub nr} is found, together with a rising ionisation yield; both are in agreement with the latest independent measurements. The analysis method is applied to the most recent ZEPLIN-III data, acquired with a significantly upgraded detector and a precision-calibrated Am-Be source, as well as to the earlier data from the first run in 2008. A new method for deriving the recoil scintillation yield, which includes sub-threshold S1 events, is also presented which confirms the main analysis.

  7. Problems associated with the effects of low doses of ionising radiations

    Anon.

    1996-01-01

    This book is the English version of the report number 34 of the Academie des Sciences, published in October 1995, and entitled 'Problemes lies aux effets des faibles doses des radiations ionisantes'. This report had been endorsed by CODER (Comite des Etudes et Rapports) on February 7, 1995. In dealing with problems associated with ionising radiation, a wide range of important aspects must be taken into account and many different international bodies are concerned with them. It was therefore though useful to make the report available in English. Several additions have been made to the original edition: it has been complemented with three appendices on the cellular, molecular and genetic effects of exposure to low doses of ionising radiations ; it was though useful to give, in addition to the references of the chapters and appendices, a summary of the main relevant work published by French research teams over the past few years; an addendum quotes some of the important contributions made over the past year; a symposium devoted to the effects of low doses of ionising radiations, and to repair enzyme systems will be organized by the Academy at the end of 1997. This will provide the opportunity to re-explore the situation in the light of the data accumulated at that time. This field is evolving rapidly and a periodic evaluation of the new data is mandatory. (authors)

  8. Health protection of persons occupationally exposed to ionising radiation in Croatia

    Zavalic, M.

    2005-01-01

    The aim of this study was to investigate the health condition of workers occupationally exposed to ionising radiation. The results for 1406 workers exposed to ionising radiations, who were regularly examined in 2004, were analysed using Statistica 5.0. The analysis included workers' case histories, frequency of illnesses and causes of temporary or permanent work disability. Of 1406 workers, 16 (1.13%) were found permanently disabled; in 11 the cause of disability was lens opacity, in 2 persistent trombocitophenia, and in 2 malignant tumour. Twenty-four workers were temporarily disabled, of whom 5 due to pregnancy. Thrombocytopenia was found in 12 men and only one woman. Anaemia was found in 4 women; dicentric chromosomes were the cause of temporary disability in one person, and tuberculosis in one person. Medical examinations of Croatian workers confirm low occupational exposure to ionising radiation. With this type of radiation, the established lens impairments could not be characterised as occupational. The two malignant tumours however were recognised as occupational diseases.(author)

  9. Study of gamma radiation between 0.1 and 1.0 MeV in the earth's atmosphere; Etude du rayonnement gamma entre 0,1 et 1 Mev dans l'atmosphere terrestre

    Boclet, D [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-01-01

    The present work is devoted to some of the particular problems arising in the detection and localisation of sources of gamma radiation situated outside the earth's atmosphere. These weak sources can only be detected and localized if care is taken to eliminate gamma and particle radiations coming from other sources in the earth's atmosphere and in space. In order to separate the various sources of background noise, generally much stronger than the radiation under study, use is made of a directional detector whose characteristics are determined as described in the first part of the following report. The closest diffuse source considered is that constituted by the earth's atmosphere. Its detailed study will make it possible both to eliminate its effect when sources outside the earth are to be measured, and to predict the amount of secondary gamma radiation emitted by the same process in other celestial bodies, the moon in particular. This work considered in the 2. and 3. parts of the report. (author) [French] La presente etude est consacree a certains des problemes particuliers poses par la detection et la localisation des sources de rayonnement gamma situees hors de l'atmosphere terrestre. Ces sources faibles ne peuvent etre detectees et localisees que si l'on se protege des rayonnements gamma et particulaires provenant d'autres sources situees dans l'atmosphere terrestre et dans l'espace. Pour separer ces divers composants parasites, en general beaucoup plus intenses que le rayonnement a etudier, nous emploierons un detecteur directif dont nous determinons les caracteristiques dans la premiere partie de l'expose qui suit. La source diffuse la plus proche que nous considerons comme parasite est constituee par l'atmosphere terrestre. Son etude detaillee nous permettra d'une part de nous en proteger lorsque nous voudrons etudier les sources {gamma} extra-terrestres, d'autre part de prevoir le rayonnement gamma secondaire emis par le meme processus pour les autres corps

  10. Amorphous silicon cells for the measurement of photosynthetically active radiation; Utilisation des cellules au silicium amorphe pour la mesure du rayonnement photosynthétiquement actif (400-700 nm)

    Chartier, M. [Institut National de la Recherche Agronomique, Thiverval-Grignon (France); Bonchretien, P.; Allirand, J. M.; Gosse, G.

    1989-07-01

    Numerical simulation and experimental measurements from amorphous silicon cells in comparison with these now used in ecophysiology illustrate the interest of amorphous silicon cells for the measurement of PAR incident, reflected, and transmitted below the canopy [French] La simulation et la confrontation expérimentale ces réponses des cellules au silicium amorphe par rapport à celles des capteurs existants montrent l’intérêt des cellules au silicium amorphe pour la mesure du rayonnement PAR (exprimé en densité de flux de photons) incident, réfléchi et transmis sous un couvert végétal.

  11. Study of gamma radiation between 0.1 and 1.0 MeV in the earth's atmosphere; Etude du rayonnement gamma entre 0,1 et 1 Mev dans l'atmosphere terrestre

    Boclet, D. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-01-01

    The present work is devoted to some of the particular problems arising in the detection and localisation of sources of gamma radiation situated outside the earth's atmosphere. These weak sources can only be detected and localized if care is taken to eliminate gamma and particle radiations coming from other sources in the earth's atmosphere and in space. In order to separate the various sources of background noise, generally much stronger than the radiation under study, use is made of a directional detector whose characteristics are determined as described in the first part of the following report. The closest diffuse source considered is that constituted by the earth's atmosphere. Its detailed study will make it possible both to eliminate its effect when sources outside the earth are to be measured, and to predict the amount of secondary gamma radiation emitted by the same process in other celestial bodies, the moon in particular. This work considered in the 2. and 3. parts of the report. (author) [French] La presente etude est consacree a certains des problemes particuliers poses par la detection et la localisation des sources de rayonnement gamma situees hors de l'atmosphere terrestre. Ces sources faibles ne peuvent etre detectees et localisees que si l'on se protege des rayonnements gamma et particulaires provenant d'autres sources situees dans l'atmosphere terrestre et dans l'espace. Pour separer ces divers composants parasites, en general beaucoup plus intenses que le rayonnement a etudier, nous emploierons un detecteur directif dont nous determinons les caracteristiques dans la premiere partie de l'expose qui suit. La source diffuse la plus proche que nous considerons comme parasite est constituee par l'atmosphere terrestre. Son etude detaillee nous permettra d'une part de nous en proteger lorsque nous voudrons etudier les sources {gamma} extra-terrestres, d'autre part de prevoir le rayonnement gamma

  12. Uses of radioactive isotopes and radiation sources in biological studies in U. A. R; Utilisation des radioisotopes et des sources de rayonnement dans les etudes biologiques en RAU

    Hashish, S. E. [Radiobiology Department, U. A. R. Atomic Energy Establishment, Cairo, United Arab Republic (Egypt)

    1970-01-15

    An attempt is made to give examples rather than a review of the uses of radioactive isotopes and radiation sources in biological studies in U.A.R. Studies along these lines started early in 1955 and are still progressing. The prospects of future developments and improvements are unlimited. The studies are classified according to the radio technique adopted. The techniques so far used in U.A.R. include all the techniques known elsewhere. Some detailed modifications and combinations of more than one technique have been successfully introduced. Both in basic and applied biological studies, one or more of the following techniques have been applied, namely tracer technique, isotopic dilution analysis, autoradiography, radiochromatography and electrophoresis, double or multi-bioassays, radioactivation analysis, neutron absorption analysis, and use of different radiation source for somatic and/or genetic effect studies. Mass spectrometry for stable isotopic studies in the field of biology has been recently used. Studies undertaken in the applied fields of biology e. g, in medicine (diagnosis and therapy) and agriculture (soil, plant and animal) have proved extremely valuable from the practical and developmental points of view. (author) [French] Le mémoire a pour objet d'illustrer plutôt que d'exposer systématiquement les utilisations des radioisotopes et des sources de rayonnement dans des études biologiques en République Arabe Unie. Ces études, entreprises au début de 1955, se poursuivent. Les possibilités de développement et de perfectionnement sont illimitées. Les études sont classées d'après la radiotechnique adoptée. Les techniques régulièrement utilisées jusqu' à présent en République Arabe Unie couvrent toute la gamme des techniques connues ailleurs. On a réussi à apporter des modifications de détail et à combiner plusieurs techniques. Dans les études de biologie tant fondamentale qu' appliquée, une ou plusieurs des techniques suivantes

  13. Fission ionisation chamber for the measurement of low fluxes of slow neutrons; Chambre d'ionisation a fission pour la mesure des faibles flux de neutrons lents

    Weill, J; Duchene, J P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    The ionisation chamber described is designed for the measurement of slow neutron fluxes of average or low intensity, in the presence, eventually, of very high gamma fluxes. The capture of a slow neutron by a fissile material, in this case {sup 235}U, gives rise to fission fragments, high-energy particles which ionise the gas contained in the chamber. The neutrons are detected by virtue of the potential pulses, on the collecting electrode of the chamber, deriving from the collection of the ions produced by the fission fragments. The pulses are counted by means of a measuring system consisting of a preamplifier, a 2 Mc amplifier, a discriminator and an electronic scale with numerator or integrator. The general characteristics are as follows: sensitivity to neutrons: 0.07 kicks/n/cm{sup 2}.s, sensitivity to {gamma} rays: zero up to 3.10{sup 4} R/H, a background noise at the normal discrimination voltage: 0.01 kicks/s, working H.T.: -500 V, capacity: 40 {mu}{mu}F, average height of pulse: 8 mV, limits of use: from several neutrons to 10{sup 6} n/cm{sup 2}.s. This chamber may be used in all cases where low fluxes of slow neutrons must be measured, especially in the presence of high gamma fluxes, for example in the checking of Pu concentrations in an extraction plant or for the starting up of reactors. (author) [French] La chambre d'ionisation decrite est destinee a la mesure des flux de neutrons lents d'intensite moyenne ou faible, en presence eventuelle de flux gamma tres importants. La capture d'un neutron lent par un materiau fissile, en l'occurrence {sup 235}U, donne naissance a des fragments de fission, particules de grande energie qui ionisent le gaz contenu dans la chambre. Les neutrons sont detectes grace aux impulsions de potentiel, sur l'electrode collectrice de la chambre, provenant de la collection des ions produits par les fragments de fission. Une chaine de mesure comprenant un preamplificateur, un amplificateur 2 Mc, un discriminateur, une echelle

  14. Thermal and radiation induced polymerisation of carbon sub-oxide; Polymerisation thermique et sous rayonnement du sous-oxyde de carbone

    Schmidt, Michel

    1964-03-15

    This research thesis addresses the study of the polymerisation of carbon sub-oxide (C{sub 3}O{sub 2}) in gaseous phase. As this work is related to other researches dealing with the reactions of the graphite-CO{sub 2} system which occur in graphite-moderated nuclear reactors, a first intention was to study the behaviour of C{sub 3}O{sub 2} when submitted to radiations. Preliminary tests showed that the most remarkable result of this action was the formation of a polymer. It was also noticed that the polymerisation of this gas was spontaneous however slower at room temperature. The research thus focused on this polymerisation, and on the formula of the obtained polymer. After some generalities, the author reports the preparation, purification and storage and conservation of the carbon sub-oxide. The next parts report the kinetic study of thermal polymerisation, the study of polymerisation under γ rays, the study of the obtained polymer by using visible, UV and infrared spectroscopy, electronic paramagnetic resonance, and semi-conductivity measurements [French] Le but de ce travail est l'etude de la polymerisation du sous-oxyde de carbone, C{sub 3}O{sub 2}, en phase gazeuse. Ce travail est en relation avec d'autres recherches concernant les reactions du systeme graphite-CO{sub 2} qui se produisent dans les reacteurs nucleaires de la filiere moderee au graphite. Notre premiere intention etait donc d'etudier le comportement de C{sub 3}O{sub 2} sous l'action des rayonnements. Or des essais preliminaires nous ont rapidement montre que le resultat le plus marquant de cette action etait l'obtention d'un polymere. On a egalement remarque que ce gaz polymerisait spontanement - quoique moins rapidement - a la temperature ambiante. Notre etude s'est donc circonscrite a cette polymerisation, avec ou sans rayonnements, ainsi qu'a son aboutissement: le polymere, dont nous avons tente d'eclaircir la formule. Au terme de cette etude, bien que certains points ne soient pas encore

  15. Studies on radiation-image detectors; Etudes sur les detecteurs a images de rayonnements; Izuchenie detektorov izobrazheniya radiatsii; Estudios sobre detectores de radiaciones productores de imagenes

    Reiffel, L [Armour Research Foundation, Chicago, IL (United States)

    1962-04-15

    data also germane to scintillation-chamber technology. Possible imaging detectors using thick blocks of material which are capable of significant energy storage and stimulated phosphorescence upon irradiation are discussed briefly along with read-out methods using optical scanning beams to eliminate resolution loss due to finite phosphor thickness. (author) [French] Le memoire decrit les travaux qui ont ete entrepris sur des detecteurs de rayonnements capables de fournir des informations tout a fait exactes sur la distribution spatiale. Il s'agit avant tout de determiner des distributions d'intensites dans un plan, ou eventuellement sur un cylindre. Cette categorie de problemes comprend la diffraction des neutrons, la radiographie des neutrons, ainsi que la radiographie aux rayons X ou {gamma} ou les etudes de diffusion avec ces rayons. L'auteur s'occupe surtout des detecteurs a images de rayonnements, fondes sur la distribution des etincelles et sur la luminescence Ou la phosphorescence stimulee. Le laboratoire de Armour Research a mis au point de tres grands compteurs a etincelles, pesant plus de 100 livres et comportant des zones sensibles de l'ordre de 2000 cm{sup 2}, definies par des assemblages de plans comprenant chacun jusqu'a 400 fils d'anode et de cathode, les anodes et les cathodes etant respectivement disposees en quinconce. Un compteur a courant gazeux contenant de l'air ou un melange d'argon et de methane constitue un systeme sensible aux rayonnements alpha; la detection des neutrons lents se fait avec des plaques en {sup 10}B enrichi. Avec d'autres gaz de remplissage l'appareil est sensible aux protons et aux electrons. La lecture de la distribution d'intensite se fait par enregistrement photographique de la distribution des etincelles. Des diagrammes de taches de Laue ont pu etre enregistres en dix minutes a l'aide du reacteur d'Armour Research fonctionnant a faible puissance; le flux de crete dans le coeur etait de 10{sup 11} n/cm{sup 2} s et le

  16. Modification of non metallic materials under the influence of the radiation and thermal retrogradation of these modifications; Modification de materiaux non metalliques sous l'influence des rayonnements et retrogradation thermique de ces modifications

    Mayer, G; Perio, P; Gigon, J; Tournarie, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1955-07-01

    The action of the radiation on solids constitute an extremely vast domain of study, which the CEA hardly begins. There is not a very long time, indeed, that we have relatively intense fluxes (6.10{sup 12} thermal neutrons by cm{sup 2}.s{sup -} {sup 1} in the center of the reactor core of Saclay). Materials submitted to radiations, were followed by the evolution of a certain number of physical properties. The study of thermal retrogradation, at moderate temperature, of the modifications provoked by the irradiation were also followed. We will limit, in this report, to expose our experiences on graphite and lithium fluoride. (M.B.) [French] L'action des rayonnements sur les solides constitue un domaine extremement vaste dont l'etude, au Commissariat a l'Energie Atomique, commence a peine. Il n'y a pas tres longtemps, en effet, que nous disposons de flux relativement intenses (6.10{sup 12} neutrons thermiques par cm{sup 2}.s{sup -1} au centre de la pile de Saclay). Dans les materiaux soumis au rayonnement nous suivons l'evolution d'un certain nombre de proprietes physiques et nous etudions la retrogradation thermique, a temperature moderee, des modifications provoquees par l'irradiation. Nous nous bornerons ici a exposer nos experiences sur le graphite et le fluorure de lithium. (M.B.)

  17. Study and industrial applications of the external slowing-down {beta}{sup -} radiation of the yttrium - 90; Etude et applications industrielles du rayonnement de freinage externe des {beta}{sup -} de l'yttrium - 90

    Leveque, P; Martinelli, P; Chauvin, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1955-07-01

    Inelastic scattering of the {beta}{sup -} particles on the nucleus gives place to the emission of a X-ray Bremsstrahlung radiation. In view of possible industrial applications, we studied the slowing-down radiation of {sup 90}(Sr + Y) sources in various materials. This pure {beta}{sup -} emitter of long period is in the fission products of uranium. Among of the industrial applications, these sources of weak X-rays energy can be used for the radiography of thin pieces, for measuring the thickness, or for the analysis by fluorescence. (M.B.) [French] La diffusion inelastique des particules {beta}{sup -} sur les noyaux donne lieu a l'emission d'un rayonnement X de freinage. En vue de possibles applications industrielles, nous avons etudie le rayonnement de freinage des sources {sup 90}(Sr + Y) dans divers materiaux. Cet emetteur {beta}{sup -} pur a longue periode se trouve dans les produits de fission de l'uranium. Parmi les applications industrielles a l'etude, ces sources de rayons X de faible energie peuvent etre utilisees pour la radiographie de pieces minces, la mesure d'epaisseurs, ou encore pour l'analyse par fluorescence. (M.B.)

  18. Significance of grafting in radiation curing reactions. Comparison of ionising radiation and UV systems

    Zilic, E.; Ng, L.; Viengkhou, V.; Garnett, J.L.

    1998-01-01

    Full text: Radiation curing is now an accepted commercial technology where both ionising radiation (electron beam) and ultra violet light (UV) sources are used. Grafting is essentially the copolymerisation of a monomer/oligomer to a backbone polymer whereas curing is the rapid polymerisation of a monomer/oligomer mixture onto the surface of the substrate. There is no time scale theoretically associated with grafting processes which can occur in minutes or hours whereas curing reactions are usually very rapid, occurring within a fraction of a second. An important difference between grafting and curing is the nature of the bonding occurring in each process. In grafting covalent carbon-carbon bonds are formed, whereas in curing, bonding usually involves weaker Van der Waals or London dispersion forces. The bonding properties of the systems are important in determining their use commercially. Thus the possibility that concurrent grafting during curing could occur in a system is important since if present, grafting would not only minimise delamination of the coated product but could also, in some circumstances, render difficulties recycling of the finished product especially if it were cellulosic. Hence the conditions for observing the occurrence of concurrent grafting during radiation curing are important. In the present paper, this problem has been studied by examining the effect that the components used in radiation curing exert on a typical reaction. Instead of electron beam sources, the spent fuel element facility at Lucas Heights is used to simulate such ionising radiation sources. The model system utilised is the grafting of a typical methacrylate to cellulose. This is the generic chemistry used in curing systems. The effect of typical additives from curing systems including polyfunctional monomer and oligomers in the grafting reactions have been studied. The ionising radiation results have been compared with analogous data from UV experiments. The significance

  19. A micro-gap, air-filled ionisation chamber as a detector for criticality accident dosimetry

    Murawski, I.; Zielczynski, M.; Gryzinski, M.A.; Golnik, N.

    2014-01-01

    A micro-gap air-filled ionisation chamber was designed for criticality dosimetry. The special feature of the chamber is its very small gap between electrodes of only 0.3 mm. This prevents ion recombination at high dose rates and minimises the influence of gas on secondary particles spectrum. The electrodes are made of polypropylene because of higher content of hydrogen in this material, when compared with soft tissue. The difference between neutron and gamma sensitivity in such chamber becomes practically negligible. The chamber's envelope contains two specially connected capacitors, one for polarising the electrodes and the other for collecting the ionisation charge. Air-filled ionisation chamber with very small gap is a simple dosemeter, which fulfills the most desired properties of criticality accident dosemeters. Short ion collection time is achieved by combination of small gap and relatively high polarising voltage. For the same reason, parasitic recombination of ions in the chamber is negligibly small even at high dose rates. The difference between neutron and gamma sensitivity is small for tissue-equivalent chamber and is expected to become practically negligible when the chamber electrodes are made of polypropylene. Additional capacitor provides a broad measuring range from ∼0.1 Gy up to ∼25 Gy; however, leakage of electrical charge from polarising capacitor has to be observed and taken into account. Periodical re-charging of the device is necessary. Obviously, final test of the device in conditions simulating criticality accident is needed and will be performed as soon as available. (authors)

  20. Synthetic diamond devices for radiotherapy applications: Thermoluminescent dosimeter and ionisation chamber

    Descamps, C.; Tromson, D.; Mer, C.; Nesladek, M.; Bergonzo, P.

    2006-01-01

    In radiotherapy field, the major usage of dosimeters is in the measurement of the dose received by the patient during radiotherapy (in-vivo measurements) and in beam calibration and uniformity checks. Diamond exhibits several interesting characteristics that make it a good candidate for radiation detection. It is indeed soft-tissue equivalent (Z=6 compared to Z=7.42 for human tissue), mechanically robust and relatively insensitive to radiation damage, chemically stable and non toxic. Moreover, the recent availability of synthetic samples, grown under controlled conditions using the chemical vapour deposition (C.V.D.) technique, allowed decreasing the high cost and the long delivery time of diamond devices. Diamond can be use for off-line dosimetry as thermoluminescent dosimeters or for on-line dosimetry as ionisation chamber [2,3]. These both applications are reported here. For this study, samples were grown in the laboratory and devices were then tested under X-ray irradiations and in clinical environment under medical cobalt source. The work described in this paper was performed in the framework of the European Integrated Project M.A.E.S.T.R.O., Methods and Advanced Equipment for Simulation and Treatment in Radio-Oncology, (6. FP) which is granted by the European Commission.The first results of this study clearly show that C.V.D. diamond detectors are suitable for dosimetry in radiotherapy applications. Moreover, for both T.L. dosimeters and ionisation chambers applications, and even though the sensitivity is subsequently reduced, nitrogen incorporation in films seems to significantly improve the dosimetric characteristics of the devices. Therefore, the optimisation of the material quality appears as a very important issue in order to increase the dosimetric characteristics of devices and more particularly, for use as thermoluminescent dosimeters, other impurities (Nickel, Phosphorus) will be tested. For ionisation chamber applications, experiments with

  1. Transcription-based model for the induction of chromosomal exchange events by ionising radiation

    Radford, I.A.

    2003-01-01

    The mechanistic basis for chromosomal aberration formation, following exposure of mammalian cells to ionising radiation, has long been debated. Although chromosomal aberrations are probably initiated by DNA double-strand breaks (DSB), little is understood about the mechanisms that generate and modulate DNA rearrangement. Based on results from our laboratory and data from the literature, a novel model of chromosomal aberration formation has been suggested (Radford 2002). The basic postulates of this model are that: (1) DSB, primarily those involving multiple individual damage sites (i.e. complex DSB), are the critical initiating lesion; (2) only those DSB occurring in transcription units that are associated with transcription 'factories' (complexes containing multiple transcription units) induce chromosomal exchange events; (3) such DSB are brought into contact with a DNA topoisomerase I molecule through RNA polymerase II catalysed transcription and give rise to trapped DNA-topo I cleavage complexes; and (4) trapped complexes interact with another topo I molecule on a temporarily inactive transcription unit at the same transcription factory leading to DNA cleavage and subsequent strand exchange between the cleavage complexes. We have developed a method using inverse PCR that allows the detection and sequencing of putative ionising radiation-induced DNA rearrangements involving different regions of the human genome (Forrester and Radford 1998). The sequences detected by inverse PCR can provide a test of the prediction of the transcription-based model that ionising radiation-induced DNA rearrangements occur between sequences in active transcription units. Accordingly, reverse transcriptase PCR was used to determine if sequences involved in rearrangements were transcribed in the test cells. Consistent with the transcription-based model, nearly all of the sequences examined gave a positive result to reverse transcriptase PCR (Forrester and Radford unpublished)

  2. Non-targeted effects of ionising radiation. Proceedings of the RISC-RAD specialised training course

    Belyakov, O.V.

    2008-12-01

    The training course 'Non-targeted effects of ionising radiation' took place at the STUK, Radiation and Nuclear Safety Authority, Helsinki, Finland 14-16 February 2005. Proceeding of this course is collected in this volume. The idea of the course was to convene a number of scientists leading in the area of non-targeted effects of ionising radiation with the aim to outline their visions for the role of these effects and outline the future directions of radiation research on the basis of their expertise. The course was supported by the RISC-RAD IP FI6R-CT-2003-508842, Euratom specific programme for research and training on nuclear energy, 6th FP of the EC. The main objectives of the training course were: (1) to clarify the mechanisms of non-targeted effects, in particular, bystander effects, genomic instability and adaptive response; (2) to look if and how non-targeted effects modulate the cancer risk in the low dose region, and whether they relate to protective or harmful functions; (3) to clarify if ionising radiation can cause non-cancer diseases or beneficial effects at low and intermediate doses; (4) address the issue of individual susceptibility and other factors modifying non-targeted responses; (5) attempt to assess the relevance of non-targeted effects for radiation protection and to set the scientific basis for a modern, more realistic, radiation safety system; (6) and finally to contribute to the conceptualisation of a new paradigm in radiation biology that would cover both the classical direct (DNA-targeted) and non-targeted (indirect) effects

  3. Health effects of low dose ionising radiation - recent advances and their implications

    1987-01-01

    The proceedings of this unusual interdisciplinary conference encompass the work of doctors, industrialists and civil servants. The discussion covers the investigation and quantification of dose response relationships for the various damaging effects of low level ionising radiation and a unified system for expressing biological damage, together with the results of epidemiological studies using models and data from the UK, Europe, Australia and the USA (including data base systems for assembling and validating data), the effects of background radiation (gamma ray and radon exposure), clustering studies, safety standards, radioactive waste discharge control and limitation through legislation and the monitoring of radioactivity in food. (author)

  4. The potential use of diamond coated tungsten tips as a field ionisation source

    Brown, A.; Prawer, S.; Legge, G.J.F.; Kostidis, L.I. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1996-12-31

    Tungsten tips are convenient for use in a high brightness gaseous phase field ionisation source. However, the lifetime of these tips is not adequate for practical use. The authors are investigating whether coating tungsten tips with diamond using Chemical Vapor Deposition (CVD) will improve the practicality of using these tips by an improvement in longevity of the source and/or an improvement in brightness due to the effects of the property of negative electron affinity which has been observed on CVD diamond. 1 ref.

  5. The potential use of diamond coated tungsten tips as a field ionisation source

    Brown, A; Prawer, S; Legge, G J.F.; Kostidis, L I [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1997-12-31

    Tungsten tips are convenient for use in a high brightness gaseous phase field ionisation source. However, the lifetime of these tips is not adequate for practical use. The authors are investigating whether coating tungsten tips with diamond using Chemical Vapor Deposition (CVD) will improve the practicality of using these tips by an improvement in longevity of the source and/or an improvement in brightness due to the effects of the property of negative electron affinity which has been observed on CVD diamond. 1 ref.

  6. Calculated ionisation potentials to determine the oxidation of vanillin precursors by lignin peroxidase.

    Have, ten, R.; Rietjens, I.M.C.M.; Hartmans, S.; Swarts, H.J.; Field, J.A.

    1998-01-01

    In view of the biocatalytic production of vanillin, this research focused on the lignin peroxidase (LiP) catalysed oxidation of naturally occurring phenolic derivatives: O-methyl ethers, O-acetyl esters, and O-glucosyl ethers. The ionisation potential (IP) of a series of model compounds was calculated and compared to their experimental conversion by LiP, defining a relative IP threshold of approximately 9.0 eV. Based on this threshold value only the O-acetyl esters and glucosides of isoeugeno...

  7. Effect of ionising radiation exposure on structure and permeability of epithelial junctions in rat ileum

    Lebrum, F.; Dublineau, I.; Grison, S.; Strup, C.; Griffiths, N.M.

    2002-01-01

    Exposure of the digestive tract to ionising radiation results in both morphological and functional alterations of the small intestine. However little is known about the effect of irradiation on the junctions playing a major role in the maintenance of epithelial barrier integrity. Thus the aim of this study was to investigate, in rat ileum, the effect of radiation exposure on the permeability of the epithelial barrier in parallel with the localization of certain inter- and intra-cellular proteins of tight and adherent junctions

  8. A front-end ASIC for ionising radiation monitoring with femto-amp capabilities

    Voulgari, E.; Noy, M.; Anghinolfi, F.; Perrin, D.; Krummenacher, F.; Kayal, M.

    2016-01-01

    An ultra-low leakage current Application Specific Integrated Circuit (ASIC) called Utopia (Ultralow Picoammeter) has been designed and fabricated in AMS 0.35 μm CMOS, in order to be used as the front-end for ionising radiation monitoring at CERN. It is based on the topology of a Current to Frequency Converter (CFC) through charge balancing and demonstrates a wide dynamic range of 8.5 decades without range changing. Due to a design aimed at minimising input leakage currents, input currents as low as 01 fA can be measured

  9. Semiempirical confrontations between theory and experiment in highly ionised complex atoms

    Curtis, L.J.

    1989-01-01

    Highly ionised complex atoms, which have many electrons stripped away but many electrons still remaining, are presently a subject of vigorous experimental study. The high precision experimentally attainable for these systems suggests their use in the investigation of higher order theoretical processes, and the specification of these interactions is essential to the development of reliable predictive methods. It is shown that parametric reductions which combine ab initio theoretical calculations with experimental observations can yield predictions of much higher precision than could be obtained from either source separately. These formulations also reveal subtle regularities in the measured data that are not exhibited by the corresponding computations, which suggest possible calculational improvements. (orig.)

  10. The low dose gamma ionising radiation impact upon cooperativity of androgen-specific proteins.

    Filchenkov, Gennady N; Popoff, Eugene H; Naumov, Alexander D

    2014-01-01

    The paper deals with effects of the ionising radiation (γ-IR, 0.5 Gy) upon serum testosterone (T), characteristics of testosterone-binding globulin (TeBG) and androgen receptor (AR) in parallel with observation of androgen (A) responsive enzyme activity - hexokinase (HK). The interdependence or relationships of T-levels with parameters of the proteins that provide androgenic regulation are consequently analyzed in post-IR dynamics. The IR-stress adjustment data reveal expediency of TeBG- and AR-cooperativity measurements for more precise assessments of endocrine A-control at appropriate emergencies. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Draft guidance notes for the protection of persons against ionising radiations arising from veterinary use

    1983-01-01

    These guidance notes have been prepared for those who use ionising radiation for diagnostic purposes in veterinary practice, either in private practices or in larger institutions. Ancillary activities such as the testing and calibration of equipment are also covered by these notes so far as they are carried out on the same premises. The guidance notes indicate procedures for the protection of all persons who may be exposed as a result of these practices, that is to say all employed and self-employed persons, apprentices and students, and members of the public. (author)

  12. Epidemiological methods of assessing risks from low level occupational exposure to ionising radiation

    Reissland, J.A.

    1982-01-01

    The resolution of radiation-attributable malignancies from the background of malignancies which are responsible for about 20% of all deaths in the Western world, presents a formidable challenge to epidemiological methods. Some of the major difficulties facing those with the task of estimating the risks associated with exposure to low level ionising radiation are discussed, particularly in the context of radiological protection. Some of the studies currently in progress are summarised and suggestions are made for other work which may help to contribute to a better understanding of the quantitative aspects of radiation risk assessment. (author)

  13. The possibility of lasing in Ne+Ar ionic molecules pumped by a hard ioniser

    Boichenko, Aleksandr M; Yakovlenko, Sergei I

    2000-01-01

    The kinetic model of relaxation in the Ne-Ar-Kr mixture pumped by a hard ioniser is constructed in connection with the analysis of the possibility of lasing at the Ne + Ar→NeAr + transition of the inert-gas ionic exciplexes. The calculations based on the typical rates of plasmachemical reactions demonstrate that the lasing is possible but difficult to realise: One needs high pressures (greater than 16 bar) and high pumping densities (∼ 1 MW cm -3 ). In the most favourable cases, the laser efficiency lies between 0.05 and 0.25%. (active media)

  14. Characterisation of the muon beams for the Muon Ionisation Cooling Experiment

    Adams, D.; Barclay, P.; Bayliss, V.; Bradshaw, T.W.; Courthold, M.; Francis, V.; Fry, L.; Hayler, T.; Hills, M.; Lintern, A.; Macwaters, C.; Nichols, A.; Preece, R.; Ricciardi, S.; Rogers, C.; Stanley, T.; Tarrant, J.; Watson, S.; Wilson, A. [Harwell Oxford, STFC Rutherford Appleton Laboratory, Didcot (United Kingdom); Adey, D.; Back, J.; Boyd, S.; Harrison, P.; Pidcott, C.; Taylor, I. [University of Warwick, Department of Physics, Coventry (United Kingdom); Alekou, A.; Apollonio, M.; Barber, G.; Colling, D.; Dobbs, A.; Dornan, P.; Fayer, S.; Fish, A.; Hunt, C.; Leaver, J.; Long, K.; Martyniak, J.; Middleton, S.; Pasternak, J.; Richards, A.; Santos, E.; Savidge, T.; Takahashi, M. [Imperial College London, Department of Physics, Blackett Laboratory, London (United Kingdom); Asfandiyarov, R.; Blondel, A.; Graulich, J.S.; Karadzhov, Y.; Verguilov, V.; Wisting, H. [Universite de Geneve, DPNC, Section de Physique, Geneva (Switzerland); De Bari, A.; Cecchet, G. [Sezione INFN Pavia (Italy); Dipartimento di Fisica Nucleare e Teorica, Pavia (Italy); Bayes, R.; Forrest, D.; Nugent, J.C.; Soler, F.J.P.; Walaron, K. [The University of Glasgow, School of Physics and Astronomy, Glasgow (United Kingdom); Bertoni, R.; Bonesini, M.; Lucchini, G. [Sezione INFN Milano Bicocca (Italy); Dipartimento di Fisica G. Occhialini, Milano (Italy); Blackmore, V.J.; Carlisle, T.; Cobb, J.H.; Lau, W.; Rayner, M.A.; Tunnell, C.D. [University of Oxford, Department of Physics, Oxford (United Kingdom); Blot, S.; Kim, Y.K. [University of Chicago, Enrico Fermi Institute, Chicago, IL (United States); Bogomilov, M.; Kolev, D.; Rusinov, I.; Tsenov, R.; Vankova, G. [St. Kliment Ohridski University of Sofia, Department of Atomic Physics, Sofia (Bulgaria); Booth, C.N.; Hodgson, P.; Nicholson, R.; Overton, E.; Robinson, M.; Smith, P.J. [University of Sheffield, Department of Physics and Astronomy, Sheffield (United Kingdom); Bowring, D.; DeMello, A.; Gourlay, S.; Li, D.; Prestemon, S.; Virostek, S.P.; Zisman, M.S. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Bravar, U. [University of New Hampshire, Durham, NH (United States); Bross, A.D.; Fitzpatrick, T.; Leonova, M.; Moretti, A.; Neuffer, D.; Popovic, M.; Rubinov, P.; Rucinski, R. [Fermilab, Batavia, IL (United States); Capponi, M.; Iaciofano, A.; Orestano, D.; Pastore, F.; Tortora, L. [Sezione INFN Roma Tre e Dipartimento di Fisica, Roma (Italy); Charnley, G.; Collomb, N.; Gallagher, A.; Grant, A.; Griffiths, S.; Hartnett, T.; Martlew, B.; Moss, A.; Muir, A.; Mullacrane, I.; Owens, P.; White, C. [STFC Daresbury Laboratory, Cheshire (United Kingdom); Coney, L.; Fletcher, R.; Hanson, G.G.; Heidt, C. [University of California, Riverside, CA (United States); Cooke, P.; Gamet, R. [University of Liverpool, Department of Physics, Liverpool (United Kingdom); Cremaldi, L.M.; Hart, T.L.; Luo, T.; Sanders, D.A.; Summers, D.J. [University of Mississippi, Oxford, MS (United States); Dick, A.J.; Ronald, K.; Whyte, C.G. [University of Strathclyde, Department of Physics, Glasgow (United Kingdom); Filthaut, F. [NIKHEF, Amsterdam (Netherlands); Freemire, B.; Hanlet, P.; Kafka, G.; Kaplan, D.M.; Rajaram, D.; Snopok, P.; Torun, Y. [Illinois Institute of Technology, Chicago, IL (United States); Hansen, O.M.; Ramberger, S.; Vretenar, M. [CERN, Geneva (Switzerland); Ishimoto, S. [Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki (Japan); Kuno, Y.; Sakamoto, H. [Osaka University, Graduate School of Science, Department of Physics, Toyonaka, Osaka (Japan); Kyberd, P.; Littlefield, M.; Nebrensky, J.J. [Brunel University, Uxbridge (United Kingdom); Onel, Y. [University of Iowa, Department of Physics and Astronomy, Iowa City, IA (United States); Palladino, V. [Universita Federico II, Sezione INFN Napoli (Italy); Dipartimento di Fisica, Napoli (Italy); Palmer, R.B. [Brookhaven National Laboratory, Upton, NY (US); Roberts, T.J. [Muons, Inc., Batavia, IL (US); Collaboration: The MICE Collaboration

    2013-10-15

    A novel single-particle technique to measure emittance has been developed and used to characterise seventeen different muon beams for the Muon Ionisation Cooling Experiment (MICE). The muon beams, whose mean momenta vary from 171 to 281 MeV/c, have emittances of approximately 1.2-2.3 {pi} mm-rad horizontally and 0.6-1.0 {pi} mm-rad vertically, a horizontal dispersion of 90-190 mm and momentum spreads of about 25 MeV/c. There is reasonable agreement between the measured parameters of the beams and the results of simulations. The beams are found to meet the requirements of MICE. (orig.)

  15. Characterisation of the Muon Beams for the Muon Ionisation Cooling Experiment

    Adams, D.; Alekou, A.; Apollonio, M.; Asfandiyarov, R.; Back, J.; Barber, G.; Barclay, P.; de Bari, A.; Bayes, R.; Bayliss, V.; Bertoni, R.; Blackmore, V.J.; Blondel, A.; Blot, S.; Bogomilov, M.; Bonesini, M.; Booth, C.N.; Bowring, D.; Boyd, S.; Bradshaw, T.W.; Bravar, U.; Bross, A.D.; Capponi, M.; Carlisle, T.; Cecchet, G.; Charnley, G.; Cobb, J.H.; Colling, D.; Collomb, N.; Coney, L.; Cooke, P.; Courthold, M.; Cremaldi, L.M.; DeMello, A.; Dick, A.; Dobbs, A.; Dornan, P.; Fayer, S.; Filthaut, F.; Fish, A.; Fitzpatrick, T.; Fletcher, R.; Forrest, D.; Francis, V.; Freemire, B.; Fry, L.; Gallagher, A.; Gamet, R.; Gourlay, S.; Grant, A.; Graulich, J.S.; Griffiths, S.; Hanlet, P.; Hansen, O.M.; Hanson, G.G.; Harrison, P.; Hart, T.L.; Hartnett, T.; Hayler, T.; Heidt, C.; Hills, M.; Hodgson, P.; Iaciofano, A.; Ishimoto, S.; Kafka, G.; Kaplan, D.M.; Karadzhov, Y.; Kim, Y.K.; Kolev, D.; Kuno, Y.; Kyberd, P.; Lau, W.; Leaver, J.; Leonova, M.; Li, D.; Lintern, A.; Littlefield, M.; Long, K.; Lucchini, G.; Luo, T.; Macwaters, C.; Martlew, B.; Martyniak, J.; Middleton, S.; Moretti, A.; Moss, A.; Muir, A.; Mullacrane, I.; Nebrensky, J.J.; Neuffer, D.; Nichols, A.; Nicholson, R.; Nugent, J.C.; Onel, Y.; Orestano, D.; Overton, E.; Owens, P.; Palladino, V.; Palmer, R.B.; Pasternak, J.; Pastore, F.; Pidcott, C.; Popovic, M.; Preece, R.; Prestemon, S.; Rajaram, D.; Ramberger, S.; Rayner, M.A.; Ricciardi, S.; Richards, A.; Roberts, T.J.; Robinson, M.; Rogers, C.; Ronald, K.; Rubinov, P.; Rucinski, R.; Rusinov, I.; Sakamoto, H.; Sanders, D.A.; Santos, E.; Savidge, T.; Smith, P.J.; Snopok, P.; Soler, F.J.P.; Stanley, T.; Summers, D.J.; Takahashi, M.; Tarrant, J.; Taylor, I.; Tortora, L.; Torun, Y.; Tsenov, R.; Tunnell, C.D.; Vankova, G.; Verguilov, V.; Virostek, S.; Vretenar, M.; Walaron, K.; Watson, S.; White, C.; Whyte, C.G.; Wilson, A.; Wisting, H.; Zisman, M.

    2013-01-01

    A novel single-particle technique to measure emittance has been developed and used to characterise seventeen different muon beams for the Muon Ionisation Cooling Experiment (MICE). The muon beams, whose mean momenta vary from 171 to 281 MeV/c, have emittances of approximately 1.5--2.3 \\pi mm-rad horizontally and 0.6--1.0 \\pi mm-rad vertically, a horizontal dispersion of 90--190 mm and momentum spreads of about 25 MeV/c. There is reasonable agreement between the measured parameters of the beams and the results of simulations. The beams are found to meet the requirements of MICE.

  16. Characterisation of the muon beams for the Muon Ionisation Cooling Experiment

    Adams, D.; Barclay, P.; Bayliss, V.; Bradshaw, T.W.; Courthold, M.; Francis, V.; Fry, L.; Hayler, T.; Hills, M.; Lintern, A.; Macwaters, C.; Nichols, A.; Preece, R.; Ricciardi, S.; Rogers, C.; Stanley, T.; Tarrant, J.; Watson, S.; Wilson, A.; Adey, D.; Back, J.; Boyd, S.; Harrison, P.; Pidcott, C.; Taylor, I.; Alekou, A.; Apollonio, M.; Barber, G.; Colling, D.; Dobbs, A.; Dornan, P.; Fayer, S.; Fish, A.; Hunt, C.; Leaver, J.; Long, K.; Martyniak, J.; Middleton, S.; Pasternak, J.; Richards, A.; Santos, E.; Savidge, T.; Takahashi, M.; Asfandiyarov, R.; Blondel, A.; Graulich, J.S.; Karadzhov, Y.; Verguilov, V.; Wisting, H.; De Bari, A.; Cecchet, G.; Bayes, R.; Forrest, D.; Nugent, J.C.; Soler, F.J.P.; Walaron, K.; Bertoni, R.; Bonesini, M.; Lucchini, G.; Blackmore, V.J.; Carlisle, T.; Cobb, J.H.; Lau, W.; Rayner, M.A.; Tunnell, C.D.; Blot, S.; Kim, Y.K.; Bogomilov, M.; Kolev, D.; Rusinov, I.; Tsenov, R.; Vankova, G.; Booth, C.N.; Hodgson, P.; Nicholson, R.; Overton, E.; Robinson, M.; Smith, P.J.; Bowring, D.; DeMello, A.; Gourlay, S.; Li, D.; Prestemon, S.; Virostek, S.P.; Zisman, M.S.; Bravar, U.; Bross, A.D.; Fitzpatrick, T.; Leonova, M.; Moretti, A.; Neuffer, D.; Popovic, M.; Rubinov, P.; Rucinski, R.; Capponi, M.; Iaciofano, A.; Orestano, D.; Pastore, F.; Tortora, L.; Charnley, G.; Collomb, N.; Gallagher, A.; Grant, A.; Griffiths, S.; Hartnett, T.; Martlew, B.; Moss, A.; Muir, A.; Mullacrane, I.; Owens, P.; White, C.; Coney, L.; Fletcher, R.; Hanson, G.G.; Heidt, C.; Cooke, P.; Gamet, R.; Cremaldi, L.M.; Hart, T.L.; Luo, T.; Sanders, D.A.; Summers, D.J.; Dick, A.J.; Ronald, K.; Whyte, C.G.; Filthaut, F.; Freemire, B.; Hanlet, P.; Kafka, G.; Kaplan, D.M.; Rajaram, D.; Snopok, P.; Torun, Y.; Hansen, O.M.; Ramberger, S.; Vretenar, M.; Ishimoto, S.; Kuno, Y.; Sakamoto, H.; Kyberd, P.; Littlefield, M.; Nebrensky, J.J.; Onel, Y.; Palladino, V.; Palmer, R.B.; Roberts, T.J.

    2013-01-01

    A novel single-particle technique to measure emittance has been developed and used to characterise seventeen different muon beams for the Muon Ionisation Cooling Experiment (MICE). The muon beams, whose mean momenta vary from 171 to 281 MeV/c, have emittances of approximately 1.2-2.3 π mm-rad horizontally and 0.6-1.0 π mm-rad vertically, a horizontal dispersion of 90-190 mm and momentum spreads of about 25 MeV/c. There is reasonable agreement between the measured parameters of the beams and the results of simulations. The beams are found to meet the requirements of MICE. (orig.)

  17. Characterisation of the muon beams for the Muon Ionisation Cooling Experiment

    Adams, D.; et al.,

    2013-10-01

    A novel single-particle technique to measure emittance has been developed and used to characterise seventeen different muon beams for the Muon Ionisation Cooling Experiment (MICE). The muon beams, whose mean momenta vary from 171 to 281 MeV/c, have emittances of approximately 1.5--2.3 \\pi mm-rad horizontally and 0.6--1.0 \\pi mm-rad vertically, a horizontal dispersion of 90--190 mm and momentum spreads of about 25 MeV/c. There is reasonable agreement between the measured parameters of the beams and the results of simulations. The beams are found to meet the requirements of MICE.

  18. X-ray spectroscopy of highly ionised atoms of Ti through Zn in a dense plasma

    Morita, Shiguro; Fujita, Junji

    1985-01-01

    X-ray spectra for several elements have been observed from a high-temperature plasma produced in a vacuum spark using a curved-crystal spectrometer. The transition wavelengths of the He-like resonance lines for Ti through Zn are determined for the first time under careful experimental treatments. The result is compared with theoretical predictions. The transition wavelengths of the Fe He-like resonance series lines up to 1s6p-1s 2 and the Kβ transition energies of Ti partially M-shell-ionised ions (Ti VI-XIII) are also determined. As a result, several satelite lines are found. (orig.)

  19. The ionisation of the primeval plasma at the time of recombination

    Jones, B.J.T.; Wyse, R.F.G.

    1984-09-01

    We rederive the equations for the ionisation of the cosmic plasma during the recombination period, correcting some of the earlier work and refining some approximations inherent in those treatments and allow for the possibility that the universe may contain substantial amounts of non-baryonic matter (the cosmic density parameter Ωsub(T) may be greater than the baryonic contribution Ωsub(B)). The results are tabulated for various Ωsub(T)h 2 and Ωsub(B)h 2 and an assumed present day radiation temperature T 0 =2.7 K. (orig./WL)

  20. Ion pair production and chemi-ionisation in collisions of He*(2sup(1,3)S) with Li

    Wang, D.P.; Tang, S.Y.; Neynaber, R.H.

    1987-01-01

    A merging-beams technique has been used to study collisions of He*(2sup(1,3)S) with Li. The He* represents a composite of 13% He(2 1 S) and 87% He(2 3 S). Absolute and relative cross sections, Q, have been measured in a range of relative kinetic energy, W, from 150 to 1500 eV for the ion pair production (IPP) of He + + Li - , and from 0.01 to 500 eV for chemi-ionisation (CI). Information obtained for CI shows that: the Penning ionisation reaction is directed with most of the Li + scattered in the incident Li direction, the He*-Li system is attractive with a measured well depth of 0.73 eV and the value of Q for total ionisation varies as Wsup(-0.34). Similarities to the He*-He* system are also given. (author)

  1. Kinematically complete study on electron impact ionisation of aligned hydrogen molecules

    Senftleben, Arne

    2009-10-28

    Within the work presented here, single ionisation of spatially aligned hydrogen molecules by 200 eV electrons was studied in a kinematically complete experiment. For the first time, a comprehensive set of fully differential cross sections (FDCS) was obtained for this process on a molecular target. The direction of the internuclear axis was derived from the fragment emission of post-collision dissociation of the residual H{sub 2}{sup +} ion. Therefore, a protonic fragment was detected in coincidence with the two final-state electrons using a dedicated reaction microscope and sophisticated data analysis. For direct ionisation into the ionic ground state, existing theoretical cross sections for aligned molecules were tested. Additionally, we observed molecular frame angular distributions of Auger electrons emitted through dissociative autoionisation of H{sub 2}. Earlier findings of kinematically incomplete experiments were reproduced, but the FDCS reveal structures so far unknown. Furthermore, for random alignment, differential cross sections at two distinct values of the mean internuclear distance were obtained, providing new arguments in the current discussion on the nature of discrepancies observed between atomic and molecular collisions. (orig.)

  2. Isotope Dilution - Thermal Ionisation Mass Spectrometric Analysis for Tin in a Fly Ash Material

    Hernandez, C.; Fernandez, M.; Quejido, A. L.

    2006-01-01

    Isotope dilution-thermal ionisation mass spectrometry (ID-TIMS) analysis has been applied to the determination of tin in a fly ash sample supplied by the EC Joint Research Centre (Ispra, Italy). The proposed procedure includes the silica gel/phosphoric acid technique for tin thermal ionisation activation and a strict heating protocol for isotope ratio measurements. Instrumental mass discrimination factor has been previously determined measuring a natural tin standard solution. Spike solutions has been prepared from 112Sn-enriched metal and quantified by reverse isotope dilution analysis. Two sample aliquots were spiked and tin was extracted with 4,5 M HCI during 25 min ultrasound esposure time. Due to the complex matrix of this fly ash material, a two-steps purification stage using ion-exchange chromatography was required prior TIMS analysis. Obtained results for the two sample-spike blends (10,10 + - 0,55 y 10,50 + - 0,64 imolg-1) are comprarable, both value and uncertainty. Also a good reproducibility is observed between measurements. The proposed ID-TIMS procedure, as a primary method and due to the lack of fly ash reference material certified for tin content, can be used to validate more routine methodologies applied to tin determination in this kind of materials. (Author) 75 refs

  3. An important step forward in continuous spectroscopic imaging of ionising radiations using ASICs

    Fessler, P. [11 rue Rabelais, 92170 Vanves (France); Coffin, J. [Institut de Recherches Subatomiques, B.P. 28, 67037 Strasbourg (France); Eberle, H. [Institut de Recherches Subatomiques, B.P. 28, 67037 Strasbourg (France); Raad Iseli, C. de [Smart Silicon Systems SA, Ch. de la Graviere 6, CH-1007 Lausanne (Switzerland); Hilt, B. [Universite de Haute-Alsace, GRPHE, 61, rue Albert Camus, 68093 Mulhouse (France); Huss, D. [Universite de Haute-Alsace, GRPHE, 61, rue Albert Camus, 68093 Mulhouse (France); Krummenacher, F. [Smart Silicon Systems SA, Ch. de la Graviere 6, CH-1007 Lausanne (Switzerland); Lutz, J.R. [Institut de Recherches Subatomiques, B.P. 28, 67037 Strasbourg (France); Prevot, G. [Institut de Recherches Subatomiques, B.P. 28, 67037 Strasbourg (France); Renouprez, A. [Institut de Recherche sur la Catalyse, 2 Avenue Albert Einstein, 69626 Villeurbanne (France); Sigward, M.H. [Institut de Recherches Subatomiques, B.P. 28, 67037 Strasbourg (France); Schwaller, B. [Universite de Haute-Alsace, GRPHE, 61, rue Albert Camus, 68093 Mulhouse (France); Voltolini, C. [Institut de Recherches Subatomiques, B.P. 28, 67037 Strasbourg (France)

    1999-01-21

    Characterization results are given for an original ASIC allowing continuous acquisition of ionising radiation images in spectroscopic mode. Ionising radiation imaging in general and spectroscopic imaging in particular must primarily be guided by the attempt to decrease statistical noise, which requires detection systems designed to allow very high counting rates. Any source of dead time must therefore be avoided. Thus, the use of on-line corrections of the inevitable dispersion of characteristics between the large number of electronic channels of the detection system, shall be precluded. Without claiming to achieve ultimate noise levels, the work described is focused on how to prevent good individual acquisition channel noise performance from being totally destroyed by the dispersion between channels without introducing dead times. With this goal, we developed an automatic charge amplifier output voltage offset compensation system which operates regardless of the cause of the offset (detector or electronic). The main performances of the system are the following: the input equivalent noise charge is 190 e rms (input non connected, peaking time 500 ns), the highest gain is 255 mV/fC, the peaking time is adjustable between 200 ns and 2 {mu}s and the power consumption is 10 mW per channel. The agreement between experimental data and theoretical simulation results is excellent.

  4. An important step forward in continuous spectroscopic imaging of ionising radiations using ASICs

    Fessler, P.; Coffin, J.; Eberle, H.; Raad Iseli, C. de; Hilt, B.; Huss, D.; Krummenacher, F.; Lutz, J.R.; Prevot, G.; Renouprez, A.; Sigward, M.H.; Schwaller, B.; Voltolini, C.

    1999-01-01

    Characterization results are given for an original ASIC allowing continuous acquisition of ionising radiation images in spectroscopic mode. Ionising radiation imaging in general and spectroscopic imaging in particular must primarily be guided by the attempt to decrease statistical noise, which requires detection systems designed to allow very high counting rates. Any source of dead time must therefore be avoided. Thus, the use of on-line corrections of the inevitable dispersion of characteristics between the large number of electronic channels of the detection system, shall be precluded. Without claiming to achieve ultimate noise levels, the work described is focused on how to prevent good individual acquisition channel noise performance from being totally destroyed by the dispersion between channels without introducing dead times. With this goal, we developed an automatic charge amplifier output voltage offset compensation system which operates regardless of the cause of the offset (detector or electronic). The main performances of the system are the following: the input equivalent noise charge is 190 e rms (input non connected, peaking time 500 ns), the highest gain is 255 mV/fC, the peaking time is adjustable between 200 ns and 2 μs and the power consumption is 10 mW per channel. The agreement between experimental data and theoretical simulation results is excellent

  5. Modelling the propagation of effects of chronic exposure to ionising radiation from individuals to populations

    Alonzo, F. [Laboratory of Environmental Modelling, DEI/SECRE/LME, Institute of Radioprotection and Nuclear Safety (IRSN), Cadarache, Building 159, BP3, 13115 St-Paul-lez-Durance Cedex (France); Laboratory of Radioecology and Ecotoxicology, DEI/SECRE/LRE, Institute of Radioprotection and Nuclear Safety (IRSN), Cadarache Building 186, BP3, 13115 St-Paul-lez-Durance Cedex (France)], E-mail: frederic.alonzo@irsn.fr; Hertel-Aas, T. [Department of Plant and Environmental Sciences, P.O. Box 5003, Norwegian University of Life Sciences, 1432 Aas (Norway); Gilek, M. [School of Life Sciences, Soedertoern University College, 14189 Huddinge (Sweden); Gilbin, R. [Laboratory of Radioecology and Ecotoxicology, DEI/SECRE/LRE, Institute of Radioprotection and Nuclear Safety (IRSN), Cadarache Building 186, BP3, 13115 St-Paul-lez-Durance Cedex (France); Oughton, D.H. [Department of Plant and Environmental Sciences, P.O. Box 5003, Norwegian University of Life Sciences, 1432 Aas (Norway); Garnier-Laplace, J. [Laboratory of Radioecology and Ecotoxicology, DEI/SECRE/LRE, Institute of Radioprotection and Nuclear Safety (IRSN), Cadarache Building 186, BP3, 13115 St-Paul-lez-Durance Cedex (France)

    2008-09-15

    This study evaluated the potential effect of ionising radiation on population growth using simple population models and parameter values derived from chronic exposure experiments in two invertebrate species with contrasting life-history strategies. In the earthworm Eisenia fetida, models predicted increasing delay in population growth with increasing gamma dose rate (up to 0.6 generation times at 11 mGy h{sup -1}). Population extinction was predicted at 43 mGy h{sup -1}. In the microcrustacean Daphnia magna, models predicted increasing delay in population growth with increasing alpha dose rate (up to 0.8 generation times at 15.0 mGy h{sup -1}), only after two successive generations were exposed. The study examined population effects of changes in different individual endpoints (including survival, number of offspring produced and time to first reproduction). Models showed that the two species did not respond equally to equivalent levels of change, the fast growing daphnids being more susceptible to reduction in fecundity or delay in reproduction than the slow growing earthworms. This suggested that susceptibility of a population to ionising radiation cannot be considered independent of the species' life history.

  6. Activity standardisation of 18F and ionisation chamber calibration for nuclear medicine

    Schrader, H.; Klein, R.; Kossert, K.

    2007-01-01

    Primary activity standardisations were performed on solutions of 18 F using 4πβ-γ coincidence counting and liquid scintillation counting (LSC) according to the CIEMAT/NIST method. A β + -emission probability of 96.86% was used for both methods. The various standardised 18 F solutions were measured in ionisation chambers of the Physikalisch-Technische Bundesanstalt (PTB) and compared by determining radionuclide calibration factors. Already in 2001 an 18 F solution had been standardised at the PTB and compared with the results of nine national metrology institutes (NMIs), using the ISOCAL IV secondary radionuclide calibrators of the National Physical Laboratory (NPL) as transfer instruments and a 68 Ge check source solution. These results were linked to the International Reference System (SIR) at the Bureau International des Poids et Mesures (BIPM) by aliquots of solutions sent by the Laboratoire National Henri Becquerel (BNM-LNHB) and the NPL. Further on, in 2005, PTB sent an aliquot of an 18 F solution to the SIR for ionisation chamber measurements. A value of the equivalent activity was determined and included in the key comparison database (KCDB). The recent PTB value of the equivalent activity of the SIR is in good agreement with the key comparison reference value determined from five NMIs. These results confirm that the standardisation of 18 F solutions can be achieved with the accuracy required for use in nuclear medicine and, in particular, for applications in positron emission tomography (PET)

  7. Nonlinear collisionless electron cyclotron interaction in the pre-ionisation stage

    Farina, D.

    2018-06-01

    Electron cyclotron (EC) wave-particle interaction is theoretically investigated in the pre-ionisation phase, much before collisions and other mechanisms can play a role. In the very first phase of a plasma discharge with EC-assisted breakdown, the motion of an electron at room temperature in a static magnetic field under the action of a localised microwave beam is nonlinear, and transition to states of larger energy can occur via wave trapping. Within a Hamiltonian adiabatic formalism, the conditions at which the particles gain energy in single beam crossing are derived in a rigorous way, and the energy variation is characterized quantitatively as a function of the wave frequency, harmonic number, polarisation and EC power and beam width. Estimates of interest for applications to tokamak start-up are obtained for the first, second and third cyclotron harmonic. The investigation confirms that electrons can easily gain energies well above the ionisation energy in most conditions at the first two harmonics, while not at the third harmonic, as observed in experiments.

  8. Fluorescence in situ hybridisation in chromosome aberration detection in subjects occupationally exposed to ionising radiation

    Zeljezic, D.; Garaj-Vrhovac, V.

    2005-01-01

    For more than two decades, chromosomal aberration analysis has been used to detect structural chromosomal aberrations as sensitive biodosimeters of occupational exposure to ionising radiation. Its use is also recommended by the World Health Organisation. Changes in chromosome structure detected by that method are considered to be early biomarkers of a possible malignant disease. Aberrations detected by the method are unstable and can be found in the lymphocytes of irradiated personnel only within a limited time after exposure. To detect stable chromosomal aberrations, which persist after exposure, multicolour fluorescent in situ hybridisation has to be used. Using DNA probes labelled with different fluorochromes, it dyes each pair of chromosomes with different colour. Due to the dynamic of unstable aberration formation, chromosomal aberration analysis is more suitable in genome damage assessment of recent exposures. On the other hand, fluorescence in situ hybridisation gives the information on chromosome instability caused by long-term occupational exposure to ionising radiation. Considering the high costs of fluorescence in situ hybridisation and the uncertainty of the result, it should be used in biodosimetry only when it is absolutely necessary.(author)

  9. Experimental determination of pcav factors for cylindrical ionisation chambers in electron beams

    Palm, Aa.; Mattsson, O.

    2000-01-01

    The electron beam method recommended for calibrating plane parallel ionisation chambers involves cavity correction factors for cylindrical chambers. The cavity correction factors in the IAEA TRS-381 Code of Practice are based on measurements at R 100 in a PMMA phantom using PMMA cylindrical chambers having different cavity radii. In the present work the recommended data were confirmed for electron beams delivered by modern medical accelerators by using the very same phantom and ionisation chambers that were used in the original work. From another series of measurements, using four specially designed wall-less chambers in a graphite phantom, the linear relation between p cav and the chamber radius that is the basis for the experimental method, was verified. The method was also used to determine the cavity correction factors for a set of Farmer-like graphite chambers placed in water. Compared to the TRS-381 Code of Practice a smaller correction was found for the cavity perturbation for the graphite chambers used in water. (author)

  10. Microdosimetric constraints on specific adaptation mechanisms to reduce DNA damage caused by ionising radiation

    Burkart, W.; Heusser, P.; Vijayalaxmi

    1990-01-01

    The protective effect of pre-exposure of lymphocytes to ionising radiation indicates the presence of 'adaptive repair' in mammalian cells. Microdosimetric considerations, however, raise some doubts on the advantage of such a cellular mechanism for specifically reducing the radiation damage caused by environmental exposures. Contrary to most chemicals which endanger the integrity of the mammalian genome, the local dose and dose rate from ionising radiation at the cellular level remain quite high, even at lowest exposures. A single electron or alpha particle passing through a cell nucleus already yields nuclear doses of up to about 3 mGy and 400 mGy, respectively. Macroscopic doses below these nuclear doses from a single event will only reduce the fraction of cell nuclei encountering the passage of a particle but not the dose or dose rate in the affected volume. At environmental doses in the range of 1 to 5 mGy per annum, the time between two consecutive hits in a specific cell nucleus is in the range of months to years. Very low concentrations of bleomycin, a drug with high affinity to DNA, also triggers an adaptive response. This points to a more general stress response mechanism which may benefit the cell even at environmental levels of radioactivity, e.g. by protecting the integrity of DNA from attacks by chemicals, by endogenous radicals, by acids from anoxia, etc. (author)

  11. Towards a Symmetric Momentum Distribution in the Muon Ionisation Cooling Experiment

    Hansen, O M; Efthymiopoulos, I

    2013-01-01

    TheMuon Ionisation Cooling Experiment (MICE) is under development at Rutherford Appleton Labratory (UK). It is a proof-of-principle experiment for ionisation cooling, which is a prerequisite for a future Neutrino Factory (NF) or a Muon Collider. The muon beam will have a symmetrical momentum distribution in the cooling channel of theNF [1]. In the MICE beamline pions are captured by a quadrupole triplet, beam momentum is selected by dipole 1 (D1) before the beam traverses the decay solenoid. After the decay solenoid the beam momentum is selected by dipole 2 (D2), the beam is focused in two quadrupole triplets and characterised by time-of-flight (TOF) detectors TOF0 and TOF1 before entering the cooling channel. By doing a so-called D1-scan, where the optics parameters are scaled according to the upstream beam momentum, the purity and momentum distribution of the decay muons are changed. In this paper simulation results from G4Beamline (G4BL) [2] and data from MICE are presented and compared.

  12. Fission ionisation chamber for the measurement of low fluxes of slow neutrons

    Weill, J.; Duchene, J.P.

    1958-01-01

    The ionisation chamber described is designed for the measurement of slow neutron fluxes of average or low intensity, in the presence, eventually, of very high gamma fluxes. The capture of a slow neutron by a fissile material, in this case 235 U, gives rise to fission fragments, high-energy particles which ionise the gas contained in the chamber. The neutrons are detected by virtue of the potential pulses, on the collecting electrode of the chamber, deriving from the collection of the ions produced by the fission fragments. The pulses are counted by means of a measuring system consisting of a preamplifier, a 2 Mc amplifier, a discriminator and an electronic scale with numerator or integrator. The general characteristics are as follows: sensitivity to neutrons: 0.07 kicks/n/cm 2 .s, sensitivity to γ rays: zero up to 3.10 4 R/H, a background noise at the normal discrimination voltage: 0.01 kicks/s, working H.T.: -500 V, capacity: 40 μμF, average height of pulse: 8 mV, limits of use: from several neutrons to 10 6 n/cm 2 .s. This chamber may be used in all cases where low fluxes of slow neutrons must be measured, especially in the presence of high gamma fluxes, for example in the checking of Pu concentrations in an extraction plant or for the starting up of reactors. (author) [fr

  13. Improved communication, understanding of risk perception and ethics related to ionising radiation.

    Perko, Tanja; Raskob, Wolfgang; Jourdain, Jean-Rene

    2016-06-06

    In Europe today, institutions, media and the general public exchange information about ionizing radiation and associated risks. However, communication about ionising radiation with the general public has to be further improved, as has been previously highlighted by international responses to the 2011 accident in Japan. This article reports the main activities and findings in this field from the following three FP7 projects: EAGLE, PREPARE and OPERRA and discussed by a broad spectrum of stakeholders at the conference RICOMET 2015. These projects, among other aims, also investigate how communication about ionising radiation in different fields could be improved and harmonised, how radiological risks are perceived, how to encourage ethical considerations in all fields of nuclear applications and what kind of transdisciplinary research is needed. The projects relate to several domains; the first relates to education, training and communication, the second to nuclear emergency preparedness and response, and the third to research and development in the radiation protection field. Incorporation of stakeholder engagement activities such as the RICOMET conference broadens social and ethical aspects and takes them into account during coordination activities as well as during core scientific and nuclear research and development performed in the projects. These activities offered opportunities for moving closer to a citizen-centred ideal of risk communication in particular and nuclear research and development in general.

  14. Adaptive response to ionising radiation induced by cadmium in zebrafish embryos

    Choi, V W Y; Ng, C Y P; Kong, M K Y; Yu, K N; Cheng, S H

    2013-01-01

    An adaptive response is a biological response where the exposure of cells or animals to a low priming exposure induces mechanisms that protect the cells or animals against the detrimental effects of a subsequent larger challenging exposure. In realistic environmental situations, living organisms can be exposed to a mixture of stressors, and the resultant effects due to such exposures are referred to as multiple stressor effects. In the present work we demonstrated, via quantification of apoptosis in the embryos, that embryos of the zebrafish (Danio rerio) subjected to a priming exposure provided by one environmental stressor (cadmium in micromolar concentrations) could undergo an adaptive response against a subsequent challenging exposure provided by another environmental stressor (alpha particles). We concluded that zebrafish embryos treated with 1 to 10 μM Cd at 5 h postfertilisation (hpf) for both 1 and 5 h could undergo an adaptive response against subsequent ∼4.4 mGy alpha-particle irradiation at 10 hpf, which could be interpreted as an antagonistic multiple stressor effect between Cd and ionising radiation. The zebrafish has become a popular vertebrate model for studying the in vivo response to ionising radiation. As such, our results suggested that multiple stressor effects should be carefully considered for human radiation risk assessment since the risk may be perturbed by another environmental stressor such as a heavy metal. (paper)

  15. Closing of Coster-Kronig transitions in multiply ionised gold atoms

    Banas, D.; Braziewicz, J.; Czarnota, M.; Fijal, I.; Jaskola, M.; Korman, A.; Kretschmer, W.; Pajek, M.; Semaniak, J.

    2003-01-01

    The paper discusses the effect of closing of L- and M-shell Coster-Kronig (CK) transitions in multiply ionised Au atoms, for which the selected CK transitions become energetically forbidden. This effect plays an important role when the Coster-Kronig energy for single-hole configuration is relatively low, being comparable with a change of the electronic binding energies in multiply ionised atom. We show, by using a simplified model, that for gold the effect of closing of CK transitions occurs for strong L 1 -L 3 M 4,5 transition for the L 1 -subshell as well as the M 3 -M 5 N 6,7 and M 4 -M 5 O 3,4 CK transitions for the M 3 - and M 4 -subshell, respectively. We demonstrate that the discussed effect of closing CK transitions substantially changes the X-ray fluorescence and Coster-Kronig yields and thus has to be considered in interpretation of X-rays excited by heavy ion impact

  16. Emissions and doses from sources of ionising radiation in the Netherlands: radiation policy monitoring

    Eleveld, H.; Pruppers, M.

    2002-01-01

    In 1997 the Ministry of Housing, Spatial Planning and the Environment requested RIVM to develop an information system for policy monitoring. One of the motives was that the European Union requires that the competent authorities of each member state ensure that dose estimates due to practices involving exposure to ionising radiation are made as realistic as possible for the population as a whole and for reference groups in all places where such groups may occur. Emissions of radionuclides and radiation to the environment can be classified as follows: (1) emissions to the atmosphere, (2) emissions to the aquatic system and (3) emission of external radiation from radioactive materials and equipment that produces ionising radiation. Released radioactivity is dispersed via exposure pathways, such as the atmosphere, deposition on the ground and farmland products, drinking water, fish products, etc. This leads to radiation doses due to inhalation, ingestion and exposure to external radiation. To assess the possible radiation doses different kinds of models are applied, varying from simple multiplications with dispersion coefficients, transfer coefficients and dose conversion coefficients to complex dispersion models. In this paper an overview is given of the human-induced radiation doses in the Netherlands. Also, trends in and the effect of policy on the radiation dose of members of the public are investigated. This paper is based on an RIVM report published recently. A geographical distribution of radiation risks due to routine releases for a typical year in the Netherlands was published earlier

  17. On magnetospheric electron impact ionisation and dynamics in Titan's ram-side and polar ionosphere – a Cassini case study

    G. R. Lewis

    2007-11-01

    Full Text Available We present data from the sixth Cassini flyby of Titan (T5, showing that the magnetosphere of Saturn strongly interacts with the moon's ionosphere and exo-ionosphere. A simple electron ionisation model provides a reasonable agreement with the altitude structure of the ionosphere. Furthermore, we suggest that the dense and cold exo-ionosphere (from the exobase at 1430 km and outward to several Titan radii from the surface can be explained by magnetospheric forcing and other transport processes whereas exospheric ionisation by impacting low energy electrons seems to play a minor role.

  18. Not to confuse 'contaminated' food and 'irradiated' or 'ionised' food

    2005-01-01

    Food contamination corresponds to the undesired presence of radioactive products in food, while irradiation is a process to which food can be deliberately submitted to improve its preservation or hygiene. This publication explains this difference. It describes the process, physical effects and health impacts of radioactive contamination of food. It briefly describes irradiation or ionisation processes, their objectives, doses of ionising radiations used on food products, undesired and harmful effects. It also indicates food products concerned by these irradiation processes, and the associated legal framework, evokes the lack of information of consumers regarding such practices, briefly evokes risks associated with irradiation installations, and indicates where these installations are located in France

  19. Deployment of the FIGAERO Iodide Time of flight (ToF)-Chemical ionisation mass spectrometer (CIMS) using X-ray ionisation in Manaus

    Bannan, T.; Bacak, A.; Priestley, M.; Adelstein, E.; Worrall, S.; Artaxo, P.; Carbone, S.; Topping, D. O.; Allan, J. D.; Coe, H.; Percival, C.

    2017-12-01

    Here the deployment of the The Filter Inlet for Gases and AEROsols (FIGAERO) coupled with the Aerodyne High Resolution (HR)-Time of flight (ToF)-Chemical ionisation mass spectrometer (CIMS) in Manaus is presented. This project utilised the Tofwerk X-ray ionisation source in the tropical rainforest in close proximity to Manaus, Brazil, at the ZF2 measurement site. The FIGAERO is a filter based technique that provides simultaneous molecular information of both the gas and particle phase. When analysing particles that have been collected the evolution of the MS signals from different compounds change independently as a function of temperature; creating a thermogram that is m/z specific. The temperature for which the desorbed signal shows a maximum for each compound has been used previously to extract vapour pressure information in laboratory characterisatio. Krieger et al. (2017) defined the homologous series of polyethylene glycols as a series of compounds that showed a very good agreement over a wide range of atmospherically relevant vapour pressures between different experimental setups. PEG samples therefore provide an ideal bench mark for characterising individual FIGAERO inlets to give vapour pressure information essential for partitioning characterisation. The PEG calibration curve has been used to validate vapour pressure measurements in a well-defined single component bases and in simple chamber experiments, results of which are presented. With a high reactivity and large ubiquitous global source, isoprene has a profound effect upon atmospheric chemistry and composition. Despite this there are still significant gaps in the understanding of the processes that lead to isoprene derived secondary organic aerosol (SOA). This project aims to provide insights into the role of isoprene in the mechanisms of production of SOA and its importance in the particulate mass budgets in the tropics and the fundamental chemical processes. The volatility and composition of

  20. La diaspora, instrument de la politique de puissance et de rayonnement de l’Inde à l’île Maurice et dans le monde

    Anouck Carsignol-Singh

    2009-11-01

    Full Text Available Les Persons of Indian Origin (PIO ont depuis le début du XXe siècle servi de levier à l’intelligentsia indienne pour rehausser l’image du pays et contribuer à son rayonnement culturel sur la scène internationale, en tant qu’ambassadeurs culturels de l’Inde dans leur pays de résidence. Aujourd’hui, les nouveaux liens établis entre New Delhi et les Non Resident Indians (NRI dépassent largement le cadre de la diplomatie culturelle, et leur mobilisation économique ou politique en faveur du traité nucléaire contribuent à l’affirmation de la puissance de l’Inde. Une analyse de la mobilisation des Indo-Mauriciens permet de mettre en lumière le double rôle du facteur diasporique dans l’émergence de l’Inde comme grande puissance régionale et internationale, en tant qu’instrument à la fois du Soft Power et de la Realpolitik de New Delhi.People of Indian Origin (PIOs have, since the beginning of the XXth century, been used by the Indian intelligentsia to promote the image of the sub-continent and diffuse India’s cultural values on the international stage, as cultural ambassadors of India in their host countries. Today, the new partnership between New Delhi and the Non Resident Indians (NRIs go beyond India’s cultural diplomacy, and the support of the Diaspora in favour of the nuclear deal plays a strategic part in the affirmation of India as an emerging power. An analysis of the mobilisation of Indo-Mauritians in line with the interests and values of India illustrates the double role of the diasporic factor in the emergence of India as a regional and global power, as a tool of New Delhi’s soft power and Realpolitik.

  1. Detection of high energy gamma radiations with liquid rare gases as scintillators; Detection des rayonnements Gamma de grande energie avec les gaz rares liquides comme scintillateurs

    Ho, Phan Xuan

    1965-11-25

    This research thesis reports the study of a sensor based on a liquid scintillator for the detection of high energy (10 to 30 MeV) gamma radiations. The scintillator is a liquefied argon or xenon rare gas. The author first studies the process of energy transfer from the particle to the sensing medium. He addresses the different involved elements and phenomena: electromagnetic radiations (Compton Effect, photoelectric effect, pair production, and total gamma absorption), charged particles (braking radiation, collisions) and application to gamma spectrometry. He describes and discusses the scintillation mechanisms (scintillation of organic and inorganic materials), the general characteristics of scintillators (impurities, converters), and then reports the practical realisation of the sensor. Results are presented and discussed [French] Dans ce travail, nous nous proposons d'etudier une technique. Il s'agit d'un detecteur a scintillateur liquide pour la detection des rayonnements gamma energiques (10 a 30 MeV). Le scintillateur utilise est un gaz rare liquefie argon ou xenon. Nous examinerons d'abord les processus de transfert de l'energie de la particule au milieu detecteur puis les mecanismes de scintillation en general pour pouvoir exploiter au mieux les phenomenes favorables. Nous presenterons ensuite la realisation pratique du detecteur. Ses qualites (et defauts) trouveront leur place dans la fin de ce memoire. Bien qu'a l'heure actuelle, par la methode de Kyropoulos, on puisse faire pousser des gros cristaux d'iodure de sodium, l'utilisation des 'gaz rares' liquefies comme scintillateurs est, grace a la brievete de la scintillation, tres utile lorsqu'on recherche un fort taux de comptage (jusqu'a 10 impulsions par seconde) ou lorsqu'on veut resoudre certains problemes de coincidence. Les cristaux NaI(Tl) de grandes dimensions sont d'un montage facile mais leur manipulation requiert beaucoup de precautions du fait qu'ils supportent tres mal les chocs thermiques

  2. Radioinitiation of Chain Branched Reactions and its Sensitization; Amorcage sous rayonnement des reactions par ramification en chaine; sensibilisation du processus; Radiatsionnoe initsiirovanie tsennykh razvetvlennykh reaktsij i ego sensibilizatsiya; Radioiniciacion de reacciones en cadena ramificadas y medios para aumentar su sensibilidad

    Barelko, E V; Kartashova, L I; Komarov, P N; Proskurnin, M A [Karpov Physico-Chemical Institute, Moscow, Union of Soviet Socialist Republics (Russian Federation)

    1960-07-15

    This paper describes the results of experiments by the writers with radioinitiation of chain branched reactions of the oxidation of organic compounds. The function of radiation as an initiating agent is described with reference to the oxidation of several unsaturated hydrocarbons and butanol. The reaction is self-accelerating and proceeds spontaneously after radiation has ceased. A detailed investigation was made of a process from oxidizing benzene, which has a high radiation resistance. The writers devised a method of sensitizing the radioinitiation of the oxidation of radiation-resistant substances by chemically inert but non-radiation-resistant substances. The main quantitative features of the process for the radiooxidation of benzene are stated to be the accumulation of various reaction products, and the effect of temperature, pressure, power and radiation dosage on the process of such accumulation. Information was obtained about the mechanism of the process. The design of circulating equipment is described. (author) [French] Dans ce memoire, les auteurs presentent les resultats d'une etude consacree a l'amorcage sous rayonnement de reactions, d'oxydation des composes organiques, par ramification en chaine. Ils montrent le role des rayonnements en tant qu'agents d'amorcage de la reaction, en citant comme exemples l'oxydation de certains hydrocarbures non satures et du butanol. La reaction possede un caractere d'auto-acceleration et continue spontanement lorsque l'action des rayonnements a cesse. La reaction d'oxydation du benzene a ete etudiee en detail; elle est caracterisee par la haute stabilite de la substance vis-a-vis de l'action des rayonnements. Les auteurs formulent les principes de la sensibilisation, par l'action de substances instables vis-a-vis des rayonnements de l'amorcage sous rayonnement de la reaction d'oxydation de substances stables vis-a-vis des rayonnements et chimiquement inertes. Le memoire fournit les caracteristiques quantitatives

  3. Study and optimization of the ionisation channel in the Edelweiss dark matter direct detection experiment; Etude et optimisation de la voie ionisation dans l'experience Edelweiss de detection directe de la matiere noire

    Censier, B

    2006-02-15

    The EDELWEISS experiment is aiming at the detection of Weakly Interactive Massive Particles (WIMPs), today's most favoured candidates for solving the dark matter issue. Background ionising particles are identified thanks to the simultaneous measurement of heat and ionisation in the detectors. The main limitation to this method is coming from the ionisation measurement, charge collection being less efficient in some part of the detectors known as 'dead' areas. The specificity of the measurement is due to the use of very low temperatures and low collection fields. This thesis is dedicated to the study of carrier trapping. It involves time-resolved charge measurements as well as a simulation code adapted to the specific physical conditions. We first present results concerning charge trapping at the free surfaces of the detectors. Our method allows to build a surface-charge in a controlled manner by irradiation with a strong radioactive source. This charge is then characterised with a weaker source which acts as a probe. In a second part of the work, bulk-trapping characteristics are deduced from charge collection efficiency measurements, and by an original method based on event localisation in the detector. The results show that a large proportion of the doping impurities are ionised, as indicated independently by the study of degradation by space-charge build-up. In this last part, near-electrodes areas are found to contain large densities of charged trapping centres, in connection with dead-layer effects. (author)

  4. Coincidence measurements with the use of detectors measuring the energy of the radiances (proportional meters and scintillation counter); Mesures de coincidences avec utilisation de detecteurs mesurant l'energie des rayonnements (compteurs proportionnels et compteur a scintillations)

    Sartory, M [Commissariat a l' Energie Atomique, Saclay(France). Centre d' Etudes Nucleaires

    1953-07-01

    In the setting of the realization of a set of installations permitting of the measures of coincidences between sorted radiances according to their energies, an installation understanding a proportional counter and a scintillation counter has been constructed and optimized. It has been used to do some measures of coincidences between X{sub K} photons and photons {gamma} issued at the time of the radioactive transformation of the selenium 75 (electronic capture). The efficiency of the proportional meter has been determined roughly. Besides, a proportional counter of solid angle neighboring of 4{pi} was able to achieve measures of coincidences while only doing one selection of amplitudes: indeed, the simultaneity of the detection of two radiances appear by an impulse whose amplitude is the sum of the amplitudes of the impulses resulting from each of the studied radiations. This method, applied to the coincidences between X-rays, permitted to bring the information on the diagram of decay of the arsenic 73. Besides, the coefficient of internal conversion of a consecutive transition to this decay has been valued. (author) [French] Dans le cadre de la realisation d'une serie de montages permettant des mesures de coincidences entre rayonnements tries d'apres leurs energies, un montage comprenant un compteur proportionnel et un compteur a scintillations a ete construit et mis au point. Il a ete utilise pour effectuer quelques mesures de coincidences entre photons X{sub K} et photons {gamma} emis lors de la transformation radioactive du selenium 75 (capture electronique). L'efficacite du compteur proportionnel a ete approximativement determinee. De plus, un compteur proportionnel d'angle solide voisin de 4{pi} a pu etre utilise pour realiser des mesures de coincidences en n'effectuant qu'une selection d'amplitudes: en effet, la simultaneite de la detection de deux rayonnements se manifeste par une impulsion dont l'amplitude est la somme des amplitudes des impulsions

  5. First Glossary of Modern Physics and Ionising Radiation Protection in Croatian

    Nodilo, M.; Petkovic, T.

    2011-01-01

    Motivation and encouragement for the Glossary were given as the research theme for the joint seminar between the Faculty of Electrical Engineering and Computing and Rudjer Boskovic Institute, within a postgraduate course subject ''Detectors and electronic instrumentation for particle physics''. A basic motivation is due to a lack of specialized literature in Croatian language in the field of protection of ionising radiation as well as the incompleteness of Croatian terminology in the same field. That is a general problem all over the World because the most glossaries are usually connected either with nuclear power plants or with an application of ionising radiation in medicine. On the other hand, a necessity for the specialized literature for radiation protection which follows a development of modern particle physics and its detection technique is rapidly growing up. A work and development on the Glossary were faced with serious difficulties, since various translations of foreign words and acronyms have already been used by various authors in Croatian literature. Different interpretations of the same term or concept, from diverse sources, had to be very often reconciled. However, the biggest challenge was finding proper Croatian words for the foreign terms, concepts, properties, and quantities which have not yet been commonly used so far in Croatian papers or/and Croatian legislative acts. According to our knowledge this seems to be the first comprehensive Glossary, describing the field of ionising radiation protection and bringing of 300 related entries (terms and guidelines). That is, certainly, the first characteristic Thesaurus in Croatian which includes background of modern physics and chemistry, particle phenomenology and its measurement, all dedicated to the radiological protection of workers, environment and people of the World. A Glossary brings a wide spectrum of terms of broad area of chemistry, radiation protection, nuclear and particle physics. A

  6. Time-dependent hydrogen ionisation in 3D simulations of the solar chromosphere. Methods and first results

    Leenaarts, J.; Wedemeyer-Bohm, S.

    2006-01-01

    Context. The hydrogen ionisation degree deviates substantially from statistical equilibrium under the conditions of the solar chromosphere. A realistic description of this atmospheric layer thus must account for time-dependent non-equilibrium effects. Aims. Advancing the realism of numerical

  7. Annual report on theoretical work of the S.T.G.I. (Section de theorie des gaz ionises)

    1984-01-01

    This report presents in a detailed form the theoretical work of the STGI (Section Theorie des Gaz Ionises). It is thus hoped that the present report will be useful for physicists interested in additional information. Works an plasma equilibrium and its evolution are shortly presented together with works on plasma heating and current drive. Kinetic theory and spectroscopy are not forgotten

  8. Testing of the effect of the entry beam tube windows of the silicon detectors of the ionisation radiation

    Kopestansky, J.; Tykva, R.; Stanek, S.

    1995-01-01

    This paper deals with testing of the entry beam tube windows of the silicon detectors of the ionisation radiation with surface barrier.The influence of the parameters of basic material and modified technologic preparation on the size and homogeneity of the windows was tested

  9. Desorption electrospray ionisation mass spectrometry: A rapid screening tool for veterinary drug preparations and forensic samples from hormone crime investigations

    Nielen, M.W.F.; Hooijerink, H.; Claassen, F.C.; Engelen, M.C.; Beek, van T.A.

    2009-01-01

    Hormone and veterinary drug screening and forensics can benefit from the recent developments in desorption electrospray ionisation (DESI) mass spectrometry (MS). In this work the feasibility of DESI application has been studied. Using a linear ion trap or quadrupole time-of-flight (TOF) MS

  10. Characterisation of exposure to non-ionising electromagnetic fields in the Spanish INMA birth cohort: Study protocol

    M. Gallastegi (Mara); M. Guxens Junyent (Mònica); A. Jiménez-Zabala (Ana); I. Calvente (Irene); M. Fernández (Marta); L. Birks (Laura); B. Struchen (Benjamin); M. Vrijheid (Martine); M. Estarlich (Marisa); M.F. Fernandez (Mariana); M. Torrent (Maties); F. Ballester (Ferran); J.J. Aurrekoetxea (Juan José); J. Ibarluzea (Jesús); D. Guerra (David); J. González (Julián); M. Röösli (Martin); L. Santa-Marina (Loreto)

    2016-01-01

    textabstractBackground: Analysis of the association between exposure to electromagnetic fields of non-ionising radiation (EMF-NIR) and health in children and adolescents is hindered by the limited availability of data, mainly due to the difficulties on the exposure assessment. This study protocol

  11. The ionisation loss of relativistic charged particles in thin gas samples and its use for particle identification. I

    Cobb, J.H.; Allison, W.W.M.; Bunch, J.N.

    1976-01-01

    A brief review shows a significant discrepancy between available data and theoretical predictions on the ionisation loss of charged particles in thin gas-filled proportional counters. The discrepancy related both to the increase of the most probable loss at relativistic velocities (relativistic rise) and to the spectrum of such losses at a given velocity (the Landau distribution). The origin of this relativistic rise is discussed in simple terms and related to the phenomena of transition radiation and Cherenkov radiation. It is shown that the failure of the prediction is due to the small number of ionising collisions in a gas. This problem is overcome by using a Monte Carlo method rather than a continuous integral over the spectrum of single collision processes. A specific mode of the atomic form factors is used with a modified Born approximation to yield the differential cross sections needed for the calculation. The new predictions give improved agreement with experiment and are used to investigate the problem of identifying particles of known momenta in the relativistic region. It is shown that by measuring the ionisation loss of each particle several hundred times over 5m or more, kaon, pion and proton separation with good confidence level may be achieved. Many gases are considered and a comparison is made. The results are also compared with the velocity resolution achievable by measuring primary ionisation. (Auth.)

  12. Study of the artificial radioactivity of the marine medium using gamma spectrometry (1962-1966); Etude de la radioactivite artificielle du milieu marin par spectrometrie gamma (1962-1966)

    Chesselet, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-07-01

    The results described in this study are relative to the artificial radioactivity of such elements as zirconium-95, niobium-95, ruthenium-103, ruthenium-106, cerium-141, cerium-144 and praseodymium-144 which were present in the atmospheric fallout between 1962 and 1964, and their incidence in superficial marine waters. Various physical, chemical or biological processes are studied by a high sensitivity gamma ray spectrometry technic, using those radioelements as 'tracers'. The change of state in sea water of an important fraction (about 50 per cent) of the radioactive particles going into the soluble phase - this phenomenon was not expected for those radioelements - controls the processes of accumulation in the planktonic biomass and the diffusion towards deeper waters. On the other hand, an 'in situ' spectrometry method is described. It enables the direct measurement in the sea of very low concentrations of some gamma ray emitters. The application of this method has made possible to carry out numerous observations in the surface waters of the Western Mediterranean sea and in the Bay of Biscay. It is shown that the mixing depth is closely connected to the depth of the thermocline. An accumulation process at this level is observed. The diffusion coefficients are similar to the thermal turbulent coefficient. The existence during several months of 'compartments' is established for the surface waters of the Bay of Biscay. From the establishment of the budget of fall-out, a comparative study shows that the rate of radioactive fallout on the maritime zone considered is always two to three times higher than on the neighbouring continental regions. Several explanations of this phenomenon are discussed. (author) [French] Les resultats decrits dans cette etude concernent la radioactivite artificielle sous forme de zirconium-95, niobium-95, ruthenium-103, ruthenium-106, cerium-141, cerium-144 et praseodyme-144 apportee par la retombee atmospherique entre 1962 et 1964 et les

  13. Study of the artificial radioactivity of the marine medium using gamma spectrometry (1962-1966); Etude de la radioactivite artificielle du milieu marin par spectrometrie gamma (1962-1966)

    Chesselet, R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-07-01

    The results described in this study are relative to the artificial radioactivity of such elements as zirconium-95, niobium-95, ruthenium-103, ruthenium-106, cerium-141, cerium-144 and praseodymium-144 which were present in the atmospheric fallout between 1962 and 1964, and their incidence in superficial marine waters. Various physical, chemical or biological processes are studied by a high sensitivity gamma ray spectrometry technic, using those radioelements as 'tracers'. The change of state in sea water of an important fraction (about 50 per cent) of the radioactive particles going into the soluble phase - this phenomenon was not expected for those radioelements - controls the processes of accumulation in the planktonic biomass and the diffusion towards deeper waters. On the other hand, an 'in situ' spectrometry method is described. It enables the direct measurement in the sea of very low concentrations of some gamma ray emitters. The application of this method has made possible to carry out numerous observations in the surface waters of the Western Mediterranean sea and in the Bay of Biscay. It is shown that the mixing depth is closely connected to the depth of the thermocline. An accumulation process at this level is observed. The diffusion coefficients are similar to the thermal turbulent coefficient. The existence during several months of 'compartments' is established for the surface waters of the Bay of Biscay. From the establishment of the budget of fall-out, a comparative study shows that the rate of radioactive fallout on the maritime zone considered is always two to three times higher than on the neighbouring continental regions. Several explanations of this phenomenon are discussed. (author) [French] Les resultats decrits dans cette etude concernent la radioactivite artificielle sous forme de zirconium-95, niobium-95, ruthenium-103, ruthenium-106, cerium-141, cerium-144 et praseodyme-144 apportee par la retombee

  14. Molecular alterations in thyroid tumors induced after exposure to ionising radiation in infancy

    Bounacer, A.; Wicker, R.; Sarasin, A.; Suarez, H.G. [Institut Gustave Roussy, 94 - Villejuif (France); Schlumberger, M.; Caillou, B. [Institut de Recherches sur le Cancer, 94 - Villejuif (France)

    1997-03-01

    We investigated the presence of molecular lesions in the ras, gsp and ret genes, in epithelial thyroid tumors developed in patients who had received ionising radiation therapy in infancy for benign or malignant conditions. Our data showed: a similar frequency of ras and gsp activating mutations in radiation-associated and `spontaneous` tumors. However, while the mutations are only transversions in the radiation-associated tumors, they are transversions as well as transitions in the `spontaneous` ones and a mutation in codon 691 giving rise to a polymorphism in the ret gene, and frequently associated to a C-cell hyperplasia in radiation-associated tumors. The frequency of this mutation was significantly higher (60%) in these tumors, than in normal controls (21%) or `spontaneous` epithelial thyroid tumors (23%). (author)

  15. Molecular alterations in thyroid tumors induced after exposure to ionising radiation in infancy

    Bounacer, A.; Wicker, R.; Sarasin, A.; Suarez, H.G.; Schlumberger, M.; Caillou, B.

    1997-01-01

    We investigated the presence of molecular lesions in the ras, gsp and ret genes, in epithelial thyroid tumors developed in patients who had received ionising radiation therapy in infancy for benign or malignant conditions. Our data showed: a similar frequency of ras and gsp activating mutations in radiation-associated and 'spontaneous' tumors. However, while the mutations are only transversions in the radiation-associated tumors, they are transversions as well as transitions in the 'spontaneous' ones and a mutation in codon 691 giving rise to a polymorphism in the ret gene, and frequently associated to a C-cell hyperplasia in radiation-associated tumors. The frequency of this mutation was significantly higher (60%) in these tumors, than in normal controls (21%) or 'spontaneous' epithelial thyroid tumors (23%). (author)

  16. Attenuation of acoustic waves through reflections at the plasma neutral gas interfaces: weakly ionised case

    Ghosal, S.K.; Sen, S.N.

    1977-01-01

    The problem of transmission of sonic waves through a weakly ionised plasma bounded in each side by a neutral gas medium has been treated by assuming the plasma to be a mixture of two intermingled fluids viz., neutral particle fluid and ion fluid in equilibrium. From a hydrodynamic analysis the wave equation for 'p', the macroscopic pressure perturbation has been obtained and it is shown that two independent wave motions, one due to the neutral particles and the other due to ions are propagated through the plasma with two different phase velocities. Assuming the usual boundary conditions at the interface, the amplitude of the transmitted wave has been calculated in case of weakly ionized plasma; the theory can be utilized for the determination of electron temperature from the measured value of attenuation if the percentage of ionization and collision cross section can be obtained independently. (author)

  17. Calculated ionisation potentials determine the oxidation of vanillin precursors by lignin peroxidase.

    ten Have, R; Rietjens, I M; Hartmans, S; Swarts, H J; Field, J A

    1998-07-03

    In view of the biocatalytic production of vanillin, this research focused on the lignin peroxidase (LiP) catalysed oxidation of naturally occurring phenolic derivatives: O-methyl ethers, O-acetyl esters, and O-glucosyl ethers. The ionisation potential (IP) of a series of model compounds was calculated and compared to their experimental conversion by LiP, defining a relative IP threshold of approximately 9.0 eV. Based on this threshold value only the O-acetyl esters and glucosides of isoeugenol and coniferyl alcohol would be potential LiP substrates. Both O-acetyl esters were tested and were shown to be converted to O-acetyl vanillin in molar yields of 51.8 and 2.3%, respectively.

  18. Electrifying atmospheres charging, ionisation and lightning in the solar system and beyond

    Aplin, Karen L

    2013-01-01

    Electrical processes take place in all planetary atmospheres. There is evidence for lightning on Venus, Jupiter, Saturn, Uranus and Neptune, it is possible on Mars and Titan, and cosmic rays ionise every atmosphere, leading to charged droplets and particles. Controversy surrounds the role of atmospheric electricity in physical climate processes on Earth; here, a comparative approach is employed to review the role of electrification in the atmospheres of other planets and their moons. This book reviews the theory, and, where available, measurements, of planetary atmospheric electricity, taken to include ion production and ion-aerosol interactions. The conditions necessary for a global atmospheric electric circuit similar to Earth’s, and the likelihood of meeting these conditions in other planetary atmospheres, are briefly discussed. Atmospheric electrification is more important at planets receiving little solar radiation, increasing the relative significance of electrical forces. Nucleation onto atmospheric ...

  19. Biological effects induced by K photo-ionisation in and near constituent atoms of DNA

    Touati, A.; Herve du Penhoot, M.A.; Fayard, B.; Champion, C.; Abel, F.; Gobert, F.; Lamoureux, M.; Politis, M.F.; Martins, L.; Ricoul, M.; Sabatier, L.; Sage, E.; Chetioui, A.

    2002-01-01

    In order to assess the lethal efficiency and other biological effects of inner shell ionisations of constituent atoms of DNA ('K' events), experiments were developed at the LURE synchrotron facility using ultrasoft X rays as a probe of K events. The lethal efficiency of ultrasoft X rays above the carbon K threshold was especially investigated using V79 cells and compared with their efficiency to induce double strand breaks in dry plasmid-DNA. A correlation between the K event efficiencies for these processes is shown. Beams of 340 eV were found to be twice as efficient at killing cells than were beams at 250 eV. In addition, a rough two-fold increase of the relative biological effectiveness for dicentric+ring induction has also been observed between 250 and 340 eV radiations. (author)

  20. Burn-up determination of irradiated thoria samples by isotope dilution-thermal ionisation mass spectrometry

    Aggarwal, S.K.; Jaison, P.G.; Telmore, V.M.; Shah, R.V.; Sant, V.L.; Sasibhushan, K.; Parab, A.R.; Alamelu, D.

    2010-03-01

    Burn-up was determined experimentally using thermal ionization mass spectrometry for two samples from ThO 2 bundles irradiated in KAPS-2. This involved quantitative dissolution of the irradiated fuel samples followed by separation and determination of Th, U and a stable fission product burn-up monitor in the dissolved fuel solution. Stable fission product 148 Nd was used as a burn-up monitor for determining the number of fissions. Isotope Dilution-Thermal Ionisation Mass Spectrometry (ID-TIMS) using natural U, 229 Th and enriched 142 Nd as spikes was employed for the determination of U, Th and Nd, respectively. Atom % fission values of 1.25 ± 0.03 were obtained for both the samples. 232 U content in 233 U determined by alpha spectrometry was about 500 ppm and this was higher by a factor of 5 compared to the theoretically predicted value by ORIGEN-2 code. (author)

  1. Chemical profile of mango (Mangifera indica L.) using electrospray ionisation mass spectrometry (ESI-MS).

    Oliveira, Bruno G; Costa, Helber B; Ventura, José A; Kondratyuk, Tamara P; Barroso, Maria E S; Correia, Radigya M; Pimentel, Elisângela F; Pinto, Fernanda E; Endringer, Denise C; Romão, Wanderson

    2016-08-01

    Mangifera indica L., mango fruit, is consumed as a dietary supplement with purported health benefits; it is widely used in the food industry. Herein, the chemical profile of the Ubá mango at four distinct maturation stages was evaluated during the process of growth and maturity using negative-ion mode electrospray ionisation Fourier transform ion cyclotron resonance mass spectrometry (ESI(-)FT-ICR MS) and physicochemical characterisation analysis (total titratable acidity (TA), total soluble solids (TSS), TSS/TA ratio, and total polyphenolic content). Primary (organic acids and sugars) and secondary metabolites (polyphenolic compounds) were mostly identified in the third maturation stage, thus indicating the best stage for harvesting and consuming the fruit. In addition, the potential cancer chemoprevention of the secondary metabolites (phenolic extracts obtained from mango samples) was evaluated using the induction of quinone reductase activity, concluding that fruit polyphenols have the potential for cancer chemoprevention. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Isotope shifts in odd and even energy levels of the neutral and singly ionised gadolinium atom

    Ahmad, S.A.; Venugopalan, A.; Saksena, G.D.

    1979-01-01

    Isotope shift studies in the gadolinium spectra have been extended in the region 4140 to 4535 A. Isotope shift Δσ(156 to 160) have been measured in 315 lines of the neutral and singly ionised gadolinium atom using a recording Fabry-Perot Spectrometer and gadolinium samples enriched in 156 Gd and 160 Gd isotopes. Some of the Gd I lines studied involve transitions from newly identified high odd levels of 4f 8 6s6p, 4f 7 5d6s7s and 4f 7 5d 3 configurations to low even levels of 4f 8 6s 2 and 4f 7 6s 2 6p configurations. Electronic configurations of the energy levels have been discussed on the basis of observed isotope shifts. In some cases assigned configurations have been revised and probable configurations have been suggested. (author)

  3. Lactobacilli and ionising radiation: an example of the application to meat and meat products

    Holzapfel, W.H.

    1992-01-01

    Ionising radiation provides a practical pasteurisation method for the terminal treatment of refrigerated vacuum-packaged meat products with the aim of shelf life extension. However, the relatively high radiation resistance (γ-D 10 = 0.70-1.2 kGy) of typical meat Lactobacilli, especially Lb. sake, selectively favours their total domination after treatments with 5 kGy. Typical meat strains show higher resistance (in term of γ-D 10 values the decimal reduction value due to irradiation) in the log (exponential) than in the stationary phase. This phenomenon was observed both in semi-synthetic broth and in meat, and may be explained in terms of a DNA repair mechanism operative during the exponential phase. Packaging under different gas atmospheres resulted in increased resistance to radiation in presence of N 2 , whilst the highest death rate was observed in presence of CO 2 . (orig.) [de

  4. Applying the ionising radiation regulations to radon in the UK workplace

    Denman, A. R.

    2008-01-01

    As a response to the identification of a health risk from workplace radon in the UK, the Ionising Radiations Regulations include the protection of workers from excessive levels of radon. Employers are required to make risk assessments, and the interpretation of the Health and Safety Executive is that the regulations apply to workplace premises in locations already designated as Radon Affected Areas for domestic purposes, with the difference that in workplaces, it is the maximum winter radon concentration rather than the annual average which is the parameter of interest. This paper discusses the rationale behind the current regulatory environment, outlines the role and duties of Accredited Radiation Protection Advisers and summarises the strategies necessary to conform to the regulations. (authors)

  5. Guidance notes for the protection of persons against ionising radiations arising from medical and dental use

    1988-01-01

    Guidance notes have been prepared by the NRPB, the Health Departments and the Health and Safety Executive for the protection of all persons against ionising radiations arising from medical and dental use. The guidance notes are a guide to good radiation protection practice consistent with regulatory requirements. The areas covered include medical and dental radiology, diagnostic X-ray equipment for medical and dental radiography, beam therapy and remotely controlled after-loading, brachytherapy, diagnostic and therapeutic uses of unsealed radioactive substances, diagnostic uses of sealed or other solid radioactive sources, patients leaving hospital after administration of radioactive substances, precautions after death of a patient whom radioactive substances have been administered, storage and movement of radioactive substances, disposal of radioactive waste and contingency planning and emergency procedures. (U.K.)

  6. Integrated cross sections for the ionisation of atomic hydrogen by electron impact

    Konovalov, D.A.; McCarthy, I.E.

    1992-05-01

    Distorted-wave Born approximation (DWBA) calculations are reported for singly-differential and total cross sections for the electron impact ionisation for atomic hydrogen at 25, 40, 60, 100, 150 and 250 eV. The theory is compared with available experiments. At all the energies except 25 eV the theory predicts a lower singly-differential cross section for the low-energy side of the secondary-electron energies (<5 eV), compared to the only available absolute measurements of Shyn (1992). The DWBA calculation is in good agreement with the experiment at 25 eV but only if e-e post-collision interaction is included in the theory in some way. 23 refs., 2 figs

  7. Revisiting Bragg's X-ray microscope: scatter based optical transient grating detection of pulsed ionising radiation.

    Fullagar, Wilfred K; Paganin, David M; Hall, Chris J

    2011-06-01

    Transient optical gratings for detecting ultrafast signals are routine for temporally resolved photochemical investigations. Many processes can contribute to the formation of such gratings; we indicate use of optically scattering centres that can be formed with highly variable latencies in different materials and devices using ionising radiation. Coherent light scattered by these centres can form the short-wavelength-to-optical-wavelength, incoherent-to-coherent basis of a Bragg X-ray microscope, with inherent scope for optical phasing. Depending on the dynamics of the medium chosen, the way is open to both ultrafast pulsed and integrating measurements. For experiments employing brief pulses, we discuss high-dynamic-range short-wavelength diffraction measurements with real-time optical reconstructions. Applications to optical real-time X-ray phase-retrieval are considered. Copyright © 2010 Elsevier B.V. All rights reserved.

  8. EPR spectroscopy for the detection of foods treated with ionising radiation

    Stachowicz, W.; Burlinska, G.; Michalik, J.; Dziedzic-Goclawska, A.; Ostrowski, K.

    1996-01-01

    The advantage of electron paramagnetic resonance spectroscopy (EPR or ESR) as a tool for the control of irradiated food lies in its sensitivity and accuracy. Ionising radiation produces, in irradiated materials, paramagnetic species of different kinds, i.e. radicals, radical-ions and paramagnetic centres, which can be measured by EPR but most of them are not stable enough to be used for the detection of irradiation. It is because radiation-induced paramagnetic species are thermodynamically less stable than surrounding molecules and take part in fast radiolytic reactions leading to the formation of final diamagnetic products that they are not detectable by the EPR method. Most of organic radicals produced by radiation in the liquid phase ae unstable but if the unpaired electron is incorporated into the complex polymeric system as in peptides and polysaccharides and is structurally isolated from the water, its stability is markedly increased. Since 1954 it is known that ionising radiation produces paramagnetic entities in biological materials, cells and tissues and some are stable enough to be observed by EPR spectroscopy at room temperature. The present paper describes and discusses that part of results obtained by this group during the period of ADMIT activity (1989-94) which are original and may be useful to those who will be working in the near future on the development of uniform control systems for the detection of irradiated food. The intention was to focus attention on these facts and data which influence the certainty of the detection in both positive and negative manner. (author)

  9. Chemically modified carbon nanotubes as material enhanced laser desorption ionisation (MELDI) material in protein profiling

    Najam-ul-Haq, M.; Rainer, M.; Schwarzenauer, T.; Huck, C.W.; Bonn, G.K.

    2006-01-01

    Biomarkers play a potential role in the early detection and diagnosis of a disease. Our aim is to derivatize carbon nanotubes for exploration of the differences in human body fluids e.g. serum, through matrix assisted laser desorption ionisation/time of flight mass spectrometry (MALDI/TOF-MS) that can be related to disease and subsequently to be employed in the biomarker discovery process. This application we termed as the material enhanced laser desorption ionisation (MELDI). The versatility of this technology is meant to increase the amount of information from biological samples on the protein level, which will have a major impact to serve the cause of diagnostic markers. Serum peptides and proteins are immobilized on derivatized carbon nanotubes, which function as binding material. Protein-loaded suspension is placed on a stainless steel target or buckypaper on aluminum target for direct analysis with MALDI-MS. The elution method to wash the bound proteins from carbon nanotubes was employed to compare with the direct analysis procedure. Elution is carried out by MALDI matrix solution to get them out of the entangled nanotubes, which are difficult to desorb by laser due to the complex nanotube structures. The advantage of these optimized methods compared to the conventional screening methods is the improved sensitivity, selectivity and the short analysis time without prior albumin and immunoglobulin depletion. The comparison of similarly modified diamond and carbon nanotubes exhibit differences in their nature to bind the proteins out of serum due to the differences in their physical characteristics. Infrared (IR) spectroscopy provided hint for the presence of tertiary amine peak at the crucial chemical step of iminodiacetic acid addition to acid chloride functionality on carbon nanotubes. Atomic absorption spectroscopy (AAS) was utilized to quantitatively measure the copper capacity of these derivatized carbon nanotubes which is a direct measure of capacity of

  10. A search for non-baryonic dark matter using an ionisation bolometer in the edelweiss experiment

    Di Stefano, Ph.

    1998-01-01

    The EDELWEISS experiment is an underground direct-detection search for hypothetical supersymmetric WIMPs that might solve the problem of dark matter. We have employed a cryogenic 70 g germanium ionisation bolometer, in which a WIMP would scatter elastically off a nucleus, creating both a heat and an ionisation signal. To offset the various electronic noises present in our necessarily small signals, we have s applied an optimal filtering technique in the frequency domain. This allows us to reach resolutions of 1.2 keV FWHM at 122 keV on north channels. It also provides good separation right down to low energies between the expected signal of nuclear recoils, and the photonic background of electron recoils which ionize more for a given energy. Calibration data show that we are able to reject 99.7 % of this background, while keeping 95% of the signal. However, our 1.17 kg.days of data searching for WIMPs show a third population encroaching on the expected signal. This is probably due to low energy photons or electrons interacting in the outer layers of the crystal, where charges are incompletely collected. Nevertheless, by trading off half of the conserved signal, we still manage to reject 98.5 % of the background. Thus the raw rate of 40 evts/d/kg/keV yields a conservative 90 % upper limit on the signal of 0.6 evts/d/kg/keV. This represents nearly a three orders of magnitude improvement for EDELWEISS, and puts the predicted supersymmetric phase space within two orders of magnitude. (author)

  11. The ionising radiations: a daily reality Las radiaciones ionizantes: una realidad cotidiana

    Eduardo Gallego Díaz

    2010-12-01

    Full Text Available This paper introduce the nature of the radioactive substances and of the ionising radiation, the effects that they cause on the matter and the available media for their detection and measure, as well as the sources of natural radiation, to which the human being are exposed. Next, in the more detailed part of this paper, it is described the wide range of ionising radiations uses in: medicine, agriculture, earth sciences, biology and in some other scientific fields, that allow to pose its impact in the perspective of facing the ones from natural sources. The article concludes that for avoiding damages it is necessary proper protection against the radioactive substances, but avoiding limitation their beneficial uses in the various ranges described. For finishing this paper, the basic principles of radiation protection are described, due to they are the its principal aim.Este trabajo introduce la naturaleza de las sustancias radiactivas y de la radiación ionizante, los efectos que causa sobre la materia y los medios disponibles para su detección y medida, así como las fuentes de radiación naturales a las que los seres humanos estamos expuestos. Seguidamente, en el apartado más amplio del trabajo, se describen las múltiples aplicaciones de las radiaciones ionizantes en la medicina, la agricultura, la industria, las ciencias de la tierra, la biología y otras ramas, lo que permite poder poner su impacto en perspectiva frente al de las fuentes naturales. La tesis final del artículo es que para evitar sufrir daños resulta necesario protegerse adecuadamente de los efectos nocivos de la radiación y las sustancias radiactivas, pero sin limitar innecesariamente su utilización beneficiosa en los numerosos ámbitos descritos. Ese es el objetivo fundamental de la protección radiológica, cuyos principios básicos se presentan para terminar.

  12. Radioactivity and tobacco; Radioactivite et tabac

    Nifenecker, H. [Centre National de la Recherche Scientifique (IN2P3/CNRS), 38 - Grenoble (France)

    2006-07-01

    We drew the parallel between the effects on the health, in particular carcinogenic, of irradiation and tobacco. As regards this last one the carcinogenic main part of its activity is, doubtless, of chemical origin (tars and nicotine), but a part could be due to the radioactivity. Indeed, the tobacco possesses an activity due to isotopes {sup 210}Pb and {sup 210}Po, daughter products of radon. This activity is 10 pico-becquerel by package of cigarette. The radioactive isotopes settle on the lung mucous membrane. The Academy of Sciences (US) so estimates the annual dose delivered in lungs to approximately 80 milli-sievert. This relatively important dose is however delivered only in a small fraction of the lung tissue (approximately 250 cm{sup 3}). Of this fact it contributes only weakly to the carcinogenic effect of the tobacco. (N.C.)

  13. Veterinary applications of ionising radiation HERCA Task Force on Veterinary Applications. Main results of the Questionnaire 'National regulatory requirements with regard to veterinary medical applications of ionising radiation' and conclusions of the TF

    Van Bladel, Lodewijk; Berlamont, Jolien; Michalczak, Herbert; Balogh, Lajos; Peremans, Kathelijne

    2013-11-01

    In the fall of 2012, the subject of radiation protection in veterinary medicine was raised during the meeting of the HERCA Board. Issues with regard to this subject had been brought to the attention of HERCA by the European College of Veterinary Diagnostic Imaging (ECVDI). In October 2012, the Board decided to charge a small Task Force (TF) to further explore the issues in this field. This TF drew up a questionnaire which looked at the general radiation protection regulatory requirements in veterinary medicine applications of ionizing radiation. The results of this study showed large differences in the requirements applicable in the HERCA member countries. The TF also noticed the increasing use of more complex imaging procedures and of different radio-therapeutic modalities, which may imply greater risks of exposure of humans to ionising radiation. These results were presented during the HERCA Board meeting in Berlin, Germany and on which the Board decided to establish a Working Group on veterinary applications of ionising radiations (WG Vet). The main results of the Questionnaire 'National regulatory requirements with regard to veterinary medicine applications of ionising radiation' is attached in Appendix

  14. Eddy covariance flux measurements of ammonia by high temperature chemical ionisation mass spectrometry

    J. Sintermann

    2011-03-01

    Full Text Available A system for fast ammonia (NH3 measurements with chemical ionisation mass spectrometry (CIMS based on a commercial Proton Transfer Reaction-Mass Spectrometer (PTR-MS is presented. It uses electron transfer reaction as ionisation pathway and features a drift tube of polyetheretherketone (PEEK and silica-coated steel. Heating the instrumental inlet and the drift tube to 180 °C enabled an effective time resolution of ~1 s and made it possible to apply the instrument for eddy covariance (EC measurements. EC fluxes of NH3 were measured over two agricultural fields in Oensingen, Switzerland, following fertilisations with cattle slurry. Air was aspirated close to a sonic anemometer at a flow of 100 STP L min−1 and was directed through a 23 m long 1/2" PFA tube heated to 150 °C to an air-conditioned trailer where the gas was sub-sampled from the large bypass stream. This setup minimised damping of fast NH3 concentration changes between the sampling point and the actual measurement. High-frequency attenuation loss of the NH3 fluxes of 20 to 40% was quantified and corrected for using an empirical ogive method. The instrumental NH3 background signal showed a minor interference with H2O which was characterised in the laboratory. The resulting correction of the NH3 flux after slurry spreading was less than 1‰. The flux detection limit of the EC system was about 5 ng m−2 s−1 while the accuracy of individual flux measurements was estimated 16% for the high-flux regime during these experiments. The NH3 emissions after broad spreading of the slurry showed an initial maximum of 150 μg m−2 s−1 with a fast decline in the following hours.

  15. Nuclear and cytoplasmic signalling in the cellular response to ionising radiation

    Szumiel, Irena

    2001-01-01

    DNA is the universal primary target for ionising radiation; however, the cellular response is highly diversified not only by differential DNA repair ability. The monitoring system for the ionising radiation-inflicted DNA damage consists of 3 apparently independently acting enzymes which are activated by DNA breaks: two protein kinases, ATM (ataxia telangiectasia mutated) and DNA-PK (DNA-dependent protein kinase) and a poly(ADP-ribose) polymerase, PARP-1. These 3 enzymes are the source of alarm signals, which affect to various extents DNA repair, progression through the cell cycle and eventually the pathway to cell death. Their functions probably are partly overlapping. On the side of DNA repair their role consists in recruiting and/or activating the repair enzymes, as well as preventing illegitimate recombination of the damaged sites. A large part of the nuclear signalling pathway, including the integrating role of TP53 has been revealed. Two main signalling pathways start at the plasma membrane: the MAPK/ERK (mitogen and extracellular signal regulated protein kinase family) 'survival pathway' and the SAPK/JNK (stress-activated protein kinase/c-Jun N-terminal kinase) 'cell death pathway'. The balance between them is likely to determine the cell's fate. An additional important 'survival pathway' starts at the insulin-like growth factor type I receptor (IGF-IR), involves phosphoinositide- 3 kinase and Akt kinase and is targeted at inactivation of the pro-apoptotic BAD protein. Interestingly, over-expression of IGF-IR almost entirely abrogates the extreme radiation sensitivity of ataxia telangiectasia cells. When DNA break rejoining is impaired, the cell is unconditionally radiation sensitive. The fate of a repair-competent cell is determined by the time factor: the cell cycle arrest should be long enough to ensure the completion of repair. Incomplete repair or misrepair may be tolerated, when generation of the death signal is prevented. So, the character and timing

  16. Non-targeted effects of ionising radiation (note). A new European integrated project, 2006-2010

    Salomaa, S.; Wright, E.G.; Hildebrandt, G.; Kadhim, M.; Little, M.P.; Prise, K.M.; Belyakov, O.V.

    2007-01-01

    Complete text of publication follows. The general objectives of the NOTE project are: (1) to investigate the mechanisms of nontargeted effects, in particular, bystander effects, genomic instability and adaptive response; (2) to investigate if and how non-targeted effects modulate the cancer risk in the low dose region, and whether they relate to protective or harmful functions; (3) to investigate if ionising radiation can cause non-cancer diseases or beneficial effects at low and intermediate doses; (4) to investigate individual susceptibility and other factors modifying non-targeted responses; (5) to assess the relevance of non-targeted effects for radiation protection and to set the scientific basis for a modern, more realistic, radiation safety system; (6) to contribute to the conceptualisation of a new paradigm in radiation biology that would cover both the classical direct (DNA-targeted) and non-targeted (indirect) effects. The NOTE brings together 19 major European and Canadian groups involved in the discovery, characterisation and mechanistic investigation of non-targeted effects of ionising radiation in cellular, tissue and animal models. The NOTE research activities are organised in six work packages. Four work packages (WPs 2-5) are problem-oriented, focussing on major questions relevant for the scientific basis of the system of radiation protection: WP2 Mechanisms of non-targeted effects, WP3 Non-cancer diseases, WP4 Factors modifying non-targeted responses, WP5 Modelling of non-targeted effects. The integration activities provided by WP6 strengthen the collaboration by supporting the access to infrastructures, mobility and training. WP7 provides dissemination and exploitation activities in the form of workshops and a public website. Managerial activities (WP1) ensure the organisation and structures for decision making, monitoring of progress, knowledge management and efficient flow of information and financing. Coordinator of the NOTE project is Prof

  17. A cascade method of training for the revised CEGB Radiological Safety Rules and the Ionising Radiations Regulations 1985

    Jackson, J.R.; John, P.G.L.

    1986-01-01

    In order to achieve compliance with the Ionising Radiations Regulations 1985 the CEGB has introduced a revised set of Radiological Safety Rule. These Rules are for implementation at all sites under the Board's control where ionising radiations are used. It was a requirement that the new Safety Rules be brought into operation on a common date and to a consistent standard of performance throughout the industry; this necessitated a considerable training programme to familiarise and inform some 8,000 staff working at a large number of locations. The training week of identified groups of staff varied widely, according to their different levels of authority and responsibility. The paper sets out the means by which the chosen cascade method of training was selected and developed, and gives details of the modular package of training material which was produced. It also relates how the management objectives were met within the constraints of an uncompromising time schedule. (author)

  18. Occupational radiation injuries from ionising rays recorded in the Federal Republic of Germany during the period between 1953 and 1979

    Soffke, R.

    1986-01-01

    An evaluation of 218 occupational diseases, which were reported between 1953 and 1979 and officially recognised as being caused by ionising rays, showed these to be made up chiefly by skin disorders (61%, equally distributed over acute and chronic forms), even though considerable percentage shares were also calculated for haematological ailments (15%) and bronchial carcinomas developed by uranium miners. There was a total of 42 deaths, 32 of which were ascribed to uranium mining and 10 to haematological diseases. In all, the annual rate of occupational diseases attributed to ionising rays shows a tendency to decline, even though the number of individuals exposed to radiation is increasing. The incidence of radiation injuries was calculated to be in the order of 0.01% for persons at risk of occupational radiation exposure. (orig./EDB) [de

  19. Ionisation differential cross section measurements for N2 at low incident energy in coplanar and non-coplanar geometries

    Sakaamini, Ahmad; Murray, Andrew James; Amami, Sadek; Madison, Don; Ning, Chuangang

    2016-01-01

    Ionisation triple differential cross sections have been determined experimentally and theoretically for the neutral molecule N 2 over a range of geometries from coplanar to the perpendicular plane. Data were obtained at incident electron energies ∼10 and ∼20 eV above the ionisation potential of the 3 σ g , 1 π u and 2 σ g states, using both equal and non-equal outgoing electron energies. The data were taken with the incident electron beam in the scattering plane ( ψ = 0°), at 45° to this plane and orthogonal to the plane ( ψ = 90°). The set of nine measured differential cross sections at a given energy were then inter-normalised to each other. The data are compared to new calculations using various distorted wave methods, and differences between theory and experiment are discussed. (paper)

  20. Characterisation of tryptic peptides of phosphorylated tyrosine hydroxylase by high-pressure liquid chromatography electrospray ionisation mass spectrometry

    Graham, Mark E.; Dickson, Phillip W.; Dunkley, Peter R.; Nagy-Felsobuki, Ellak I. von

    2005-01-01

    Tyrosine hydroxylase (TH) is involved in the biosynthesis of catecholamines and is activated by phosphorylation. Phosphorylated TH was analysed using high-pressure liquid chromatography combined with electrospray mass spectrometry (HPLC ESI-MS). Two mass scanning methods were used to detect tryptic cleavage products of TH. In the positive electrospray ionisation mode (ESI+), the peptides that contain the phosphorylation sites of TH were identified. In the alternative method, a phosphopeptide was detected in the negative electrospray ionisation mode (ESI-) using single ion monitoring in combination with a sequential ESI+ switching experiment. A raised baseline interfered with detection of hydrophilic peptides in ESI-, with the signal-to-noise ratio indicating that the method was operating near the limit of detection for a conventional electrospray source. The switching method improved the certainty of identification of phosphopeptides

  1. Transposition of the 97/43 EURATOM directive. Mission on procedures and standard levels of medical examinations using ionizing radiations. The radiological procedures: quality criteria and doses optimization; Transposition de la directive 97/43 Euratom. Mission sur les procedures et les niveaux de reference des examens medicaux utilisant les rayonnements ionisants. Les procedures radiologiques: criteres de qualite et optimisation des doses

    NONE

    2001-07-01

    The objective of this report concerns the optimization of radiological practices, to avoid delivering unuseful doses while ensuring an image quality necessary to the obtaining of the desired diagnosis information. (N.C.)

  2. Order of the 30 December 2004 relative to the individual sheet of medical follow-up and to the individual information concerning the dosimetry of workers exposed to ionizing radiations; Arrete du 30 decembre 2004 relatif a la carte individuelle de suivi medical et aux informations individuelles de dosimetrie des travailleurs exposes aux rayonnements ionisants

    NONE

    2004-12-15

    This order concerns the content and the modalities of grant of the individual sheet of medical follow-up, the collect and the centralization of dosimetry individual information by the Institute of Radiation Protection and Safety (IRSN), and the access to individual results of external and internal dosimetry. (A.L.B.)

  3. Adaptive response to ionizing radiation in normal human skin fibroblasts. Enhancement of DNA repair rate and modulation of gene expression. Reponse adaptative au rayonnement ionisant des fibroblastes de peau humaine. Augmentation de la vitesse de reparation de l'ADN et variation de l'expression des genes

    Toledo, S.M. de; Mitchel, R.E.J. (Atomic Energy of Canada Ltd., Chalk River, ON (Canada). Chalk River Nuclear Labs.); Azzam, E. (Atomic Energy of Canada Ltd., Chalk River, ON (Canada). Chalk River Nuclear Labs. Ottawa Univ., ON (Canada). Dept. of Biology); Raaphorst, G.P. (Ottawa Univ., ON (Canada). Dept. of Biology)

    Low doses and dose rates of ionizing radiation enhance the rate of DNA repair in human fibroblasts and protect the cells against radiation-induced micronucleus formation. Chronic exposures reduce the mRNA levels of the genes topoisomerase II and FACC-1 (Fanconi's anemia, group C). (authors). 11 refs., 1 tab., 2 figs.

  4. Exposure to ionizing radiations having a medical origin. Propositions for the implementation and the development of epidemiology surveillance activities in general population; Exposition aux rayonnements ionisants d'origine medicale. Propositions pour la mise en place et le developpement d'activites de surveillance epidemiologique en population generale

    NONE

    2002-09-01

    This report gives propositions relative to the implementation and the development of epidemiology surveillance activities in general population in relation with medical exposure to ionizing radiations. It is intended for the General Direction of Health and General Direction of Nuclear Safety and Radiation Protection. These propositions have been elaborated by a work group coordinated and run by InVS and gathering the following organisms: French Agency of sanitary safety of health products (A.F.S.S.A.P.S.), Center of Quality Assurance of technological applications in the area of health (C.A.A.T.S.), Direction of Hospitals and Care organization (D.H.O.S.), General Direction of Health (D.G.S.), General Direction of Nuclear Safety and Radiation Protection (D.G.S.N.R.), National Federation of radiologists physicists (F.N.M.R.), institute of Radiation Protection and Nuclear Safety (I.R.S.N.), INSERM 'epidemiology of cancers', French Society of Biology and Nuclear Medicine (S.F.B.M.N.), French Society of Medical Physics (S.F.P.M.), French Society of Radiology (S.F.R.). (N.C.)

  5. Contribution to the study of the {alpha} spectrometry by the impulse ionization chamber. Application to the study of the beam fine structure of some heavy nuclei; Contribution a l'etude de la spectrometrie {alpha} par la chambre d'ionisation a impulsion. Application a l'etude de la structure fine du rayonnement de quelques noyaux lourds

    Valladas, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1954-05-15

    In the first part, it studies an impulse spectrometer of which the resolution and stability have been pushed to their maximum possibilities. It uses an ionization chamber because of its simple and steady functioning. The general characteristics and building of the ionization chamber are described. The electronic devices are described as well as the recording system. The theoretical study of the amplifier has allowed to reduce the amplitude dispersion from electronic devices as background noise. The resolution in energy of an {alpha} spectrometer using an impulse ionization chamber is studied and results are discussed. The spectral lines display of the fine structure under the effect of conversion electrons emitted by coincidence in the ionization chamber is studied. Finally, the detection possibilities of very low intensity spectral lines of fine structure of detection are considered. In the second part, the {alpha} emission of fine structure of {sup 230}Th, {sup 234}U and {sup 238}U nuclei is studied. (M.P.)

  6. Assessment of risks associated to ionizing radiations: lung cancers after domestic radon exposure and thyroid cancers after accidental exposure to radioactive iodines; Evaluation des risques associes aux rayonnements ionisants: cancers du poumon apres exposition domestique au radon et cancers de la thyroide apres exposition accidentelle aux iodes radioactifs

    Catelinois, O

    2004-09-15

    The aim of this work is to develop a critical analysis of quantitative risk assessment in the field of ionizing radiation and to provide new estimates of attributable risks for particular situations of environmental exposure to ionizing radiation. This work is based on knowledge about dose-response relationships and ionizing radiation exposure of the general population. The work focuses on two different situations that both present an important interest for public health: lung cancer associated with domestic radon exposures (natural situation) and thyroid cancer associated with the Chernobyl accident fallout (accidental situation). The assessment of lung cancer risk associated with domestic radon exposure considers 10 dose-response relationships resulting from miner cohorts and case-control studies in the general population. A critical review of available data on smoking habits has been performed and allowed to consider the interactions between radon and tobacco. The exposure data come from measurements campaigns carried out since the beginning of the 1980 by the Institute for Radiation protection and Nuclear Safety and the Health General Directory in France. The French lung cancer mortality data are provided by the I.N.S.E.R.M.. Estimates of the number of attributable cancers are carried out for the whole country, stratified by 8 large regions (Z.E.A.T.) and by 96 departments for the year 1999 allowing to perform a sensibility analysis according to the geographical level of calculation. Uncertainties associated to risk coefficients and exposures have been quantified and it's impact on risk estimates is calculated. The estimated number of deaths attributable to domestic radon exposure ranges from 543 (90% uncertainty interval (U.I.): 75-1,097) to 3,108 (90% U.I.: 2,996-3,221). The corresponding risk fractions range from 2.2% (90% U.I.: 0.3%-4.4%) to 12.4% (90% U.I.: 11.9%-12.8%). The assessment of thyroid cancer risk in the most exposed area of France due to the Chernobyl nuclear power plant accident fallout, is based on the excess relative risk model published by E. Ron et al. in 1995. The target population is composed of all children younger than 15 years and living in the eastern part of France at the time of the accident (26 April 1986). The incidence rates between 1978 and 1997 are analysed and forecasted up to 2007 using age-period-cohort models. Thyroid doses are estimated from all available data about the contamination in France from the Chernobyl fallout/ The risks characterization is carried out by considering various scenarios on the projection of spontaneous incidence rates, the effectiveness of internal exposures compared to external ones and the levels of radioactive deposits. Uncertainties to the risk coefficient, the expected spontaneous incidence rates and the thyroid dose are considered. The estimated number of thyroid cancer cases in excess between 1991 and 2007 for the target population ranges from 5 (90% U.I.: 1-15) to 63 (90% U.I. 12-180). In comparison, depending on the scenario of spontaneous rate projection, the number of spontaneous cancer cases should range from 894 (90% U.I.: 869-920) to 1,716 (90% U.I.:1,691-1,741) between 1991 and 2007. The results show that the thyroid cancer incident rate increase observed in France during last 20 years cannot be explained by the Chernobyl fallout. The work provides an adaptation of the classical risk assessment method integrating each of its step such as a discussion about the choice of the dose-response relationship. The data analysis considers the interaction between ionizing radiation and other risk factors, a spontaneous incidence rate projection and a quantification of uncertainties. This work provides new results showing the importance of the choice of the dose-response relationship, of the consideration of the spontaneous incidence trend and of the quantification of uncertainties in risk assessment. In conclusion, this work provides new knowledge for public health by the analysis of enlarged epidemiological data. (author)

  7. Surveillance of occupational exposure to ionizing radiation in the French air force: an example with a workplace study concerning the flight personnel on the E-3F; Surveillance de l'exposition professionnelle aux rayonnements ionisants dans l'armee de l'air. Exemple d'une etude de poste concernant les personnels navigants sur E-3F

    Amabile, J.C.; Castagne, X.; Carbonnieres, H. de; Laroche, P. [Hopital des Armees du Val-de-Grace, 75 - Paris (France)

    2006-12-15

    This workplace study was first based on measurements of the ambient dose rates on board the E-3F (2000 to 2001). These results have been complemented by a series of measurements of individual exposure using passive and active gamma and neutrons dosimeters (2004 to 2005). We show that, from level 300 and after more than 200 flying hours per year, the air-crews of the French Air Force flying on board the E-3F are likely to annually receive an effective dose higher than 1 mSv. It is therefore necessary to organize a specific radiological and medical survey in favour of the air-crews of the E-3F and other aircraft with the same flight criteria. (authors)

  8. Register of legislative and regulatory dispositions relative to the radiation protection of the population and workers against the dangers of ionizing radiations; Recueil des dispositions legislatives et reglementaires concernant la protection de la population et des travailleurs contre les dangers des rayonnements ionisants

    NONE

    2003-12-15

    This collection of legislative arrangements concerns the protection of population and workers against the risks of ionizing radiations. Each chapter is divided in two parts: a legislative part and a statutory or regulation part. We find the different chapters in relation with protection of populations, protection of workers, public health and labour laws. (N.C.)

  9. Preparation and characterization of a ferrimagnetic amorphous alloy of GdCo entering the design of magnetic tunnel junctions: ionizing radiations hardness of magnetic tunnel junctions; preparation et caracterisation d'un alliage amorphe ferrimagnetique de GdCo entrant dans la conception de jonctions tunnel magnetiques. Resistance des jonctions tunnel magnetiques aux rayonnements ionisants

    Conraux, Y

    2005-10-15

    The magnetic random access memories (MRAM) are on the way to supplant the other forms of random access memories using the states of electric charge, and this thanks to their many technical advantages: not-volatility, speed, low consumption power, robustness. Also, the MRAM are alleged insensitive with the ionizing radiations, which was not checked in experiments until now. The current architecture of the MRAM is based on the use of magnetic tunnel junctions (MTJ). These MRAM can present an important disadvantage, because they are likely of present errors of addressing, in particular when integration (density of memory cells) is increasingly thorough. The work undertaken during this thesis relates to these two points: - to check the functional reliability of the MRAM containing JTM exposed to high energy ionizing radiations; - to study a ferrimagnetic amorphous alloy, GdCo, likely to enter the composition of JTM and allowing to free from the possible errors of addressing by a process of thermal inhibition of the memory cells. This work of thesis showed that the MRAM containing JTM preserve their functional properties fully when they are subjected to intense ionizing radiations, and that GdCo is a very interesting material from the point of view of the solid state physics and magnetism, that its physical properties are very promising as for its applications, and that its integration in a JTM still claims technological developments. (author)

  10. Declaration and authorization forms for the fabrication, distribution or use of radioactive sources or electric generators of ionizing radiation; Formulaires de declaration et d'autorisation de fabrication, de distribution ou d'utilisation de sources radioactives ou de generateurs electriques de rayonnements ionisants

    NONE

    2010-07-01

    This document gathers all the forms to be completed when declaring or when asking for an authorization for the fabrication, retailing or use of radioactive sources or electric equipment generating ionizing radiation. These forms can concern all domains (use of sealed radioactive sources, possession and use of a particle accelerator or of radionuclides, import or export of radionuclides or of products containing radionuclides), or the use of such materials or equipment in the medical sector, or the fabrication and use in industry or research, or in user's guides for radioactive sources

  11. Synthesis and evaluation of new organic and phosphorous derivatives against ionizing radiation: study of the in vitro mechanism of action; Synthese et evaluation de nouveaux composes organiques et phosphores contre les effets des rayonnements ionisants. Etude de leur mecanisme d'action in vitro

    Prouillac, C

    2006-10-15

    This work falls under a research program. The aim was to synthesize new organic phosphorylated compounds having an interesting radio pharmacological activity without toxicity. That is why, we carried out the synthesis of new benzothiazole and thiadiazole N-substituted derivatives as thiols, amino thiols, acids thio-sulfonic and phosphoro thioates. All these compounds were characterized by NMR (proton, carbon, phosphorus, 2D), by mass spectrometry, elementary analyzes and for some of them by diffraction of x-rays. The activity of the majority of them was evaluated by in vitro tests. The experimental results were confirmed by theoretical study: the aim of D.F.T. calculation was the study of the mechanism of capture of the free radicals by our compounds. In addition, a study of relation structure activity (Q.S.A.R.) was carried out. Our results allow us to create a model making it possible to establish structure-activity relationship. (author)

  12. Assessment of risks associated to ionizing radiations: lung cancers after domestic radon exposure and thyroid cancers after accidental exposure to radioactive iodines; Evaluation des risques associes aux rayonnements ionisants: cancers du poumon apres exposition domestique au radon et cancers de la thyroide apres exposition accidentelle aux iodes radioactifs

    Catelinois, O

    2004-09-15

    The aim of this work is to develop a critical analysis of quantitative risk assessment in the field of ionizing radiation and to provide new estimates of attributable risks for particular situations of environmental exposure to ionizing radiation. This work is based on knowledge about dose-response relationships and ionizing radiation exposure of the general population. The work focuses on two different situations that both present an important interest for public health: lung cancer associated with domestic radon exposures (natural situation) and thyroid cancer associated with the Chernobyl accident fallout (accidental situation). The assessment of lung cancer risk associated with domestic radon exposure considers 10 dose-response relationships resulting from miner cohorts and case-control studies in the general population. A critical review of available data on smoking habits has been performed and allowed to consider the interactions between radon and tobacco. The exposure data come from measurements campaigns carried out since the beginning of the 1980 by the Institute for Radiation protection and Nuclear Safety and the Health General Directory in France. The French lung cancer mortality data are provided by the I.N.S.E.R.M.. Estimates of the number of attributable cancers are carried out for the whole country, stratified by 8 large regions (Z.E.A.T.) and by 96 departments for the year 1999 allowing to perform a sensibility analysis according to the geographical level of calculation. Uncertainties associated to risk coefficients and exposures have been quantified and it's impact on risk estimates is calculated. The estimated number of deaths attributable to domestic radon exposure ranges from 543 (90% uncertainty interval (U.I.): 75-1,097) to 3,108 (90% U.I.: 2,996-3,221). The corresponding risk fractions range from 2.2% (90% U.I.: 0.3%-4.4%) to 12.4% (90% U.I.: 11.9%-12.8%). The assessment of thyroid cancer risk in the most exposed area of France due to the Chernobyl nuclear power plant accident fallout, is based on the excess relative risk model published by E. Ron et al. in 1995. The target population is composed of all children younger than 15 years and living in the eastern part of France at the time of the accident (26 April 1986). The incidence rates between 1978 and 1997 are analysed and forecasted up to 2007 using age-period-cohort models. Thyroid doses are estimated from all available data about the contamination in France from the Chernobyl fallout/ The risks characterization is carried out by considering various scenarios on the projection of spontaneous incidence rates, the effectiveness of internal exposures compared to external ones and the levels of radioactive deposits. Uncertainties to the risk coefficient, the expected spontaneous incidence rates and the thyroid dose are considered. The estimated number of thyroid cancer cases in excess between 1991 and 2007 for the target population ranges from 5 (90% U.I.: 1-15) to 63 (90% U.I. 12-180). In comparison, depending on the scenario of spontaneous rate projection, the number of spontaneous cancer cases should range from 894 (90% U.I.: 869-920) to 1,716 (90% U.I.:1,691-1,741) between 1991 and 2007. The results show that the thyroid cancer incident rate increase observed in France during last 20 years cannot be explained by the Chernobyl fallout. The work provides an adaptation of the classical risk assessment method integrating each of its step such as a discussion about the choice of the dose-response relationship. The data analysis considers the interaction between ionizing radiation and other risk factors, a spontaneous incidence rate projection and a quantification of uncertainties. This work provides new results showing the importance of the choice of the dose-response relationship, of the consideration of the spontaneous incidence trend and of the quantification of uncertainties in risk assessment. In conclusion, this work provides new knowledge for public health by the analysis of enlarged epidemiological data. (author)

  13. Priorities in radiation protection. Propositions for a better protection of persons against the danger of ionizing radiations. Report of the Vrousos commission; Priorites en radioprotection. Propositions pour une meilleure protection des personnes contre les dangers des rayonnements ionisants. Rapport de la commission Vrousos

    NONE

    2004-03-15

    this report presents priorities for actions and recommendations on subjects such communication, information, education, and also research, monitoring of technological development, expertise or giving users more responsibility. these recommendations are given with actions propositions on field of workers radiation protection or patients protection or radioactive sources management. (N.C.)

  14. Decree no. 2003-296 on the 31 of march 2003 relative to the workers protection against the ionizing radiations; Decret no. 2003-296 du 31 mars 2003 relatif a la protection des travailleurs contre les dangers des rayonnements ionisants

    NONE

    2003-07-01

    The different conditions modifying the Labour code in relation with the radiation protection of workers are exposed in detail, from the occupational exposure in normal conditions, the organisation of radiation protection, the abnormal working conditions until the medical examinations and medical follow up. (N.C.)

  15. Health and biological effects of non-ionizing radiations. Meeting of the non-ionizing radiation section of the French radiation protection society (SFRP). Meeting review; Les effets biologiques et sanitaires des rayonnements non ionisants. Journee scientifique de la section RNI de la SFRP - Compte rendu de congres

    Perrin, A.; Souques, M. [Electricite de France (EDF), 75 - Paris (France)

    2011-07-15

    This document makes a review of this conference day on biological and health effects of non-ionizing radiations. The program comprised three sessions with a total of 17 presentations dealing with: 1 - NMR: biological effects and implications of Directive 2004/40 on electromagnetic fields (S. Lehericy); 2 - impact of RF frequencies from mobile telephone antennas on body homeostasis (A. Pelletier); 3 - expression of stress markers in the brain and blood of rats exposed in-utero to a Wi-Fi signal (I. Lagroye); 4 - people exposure to electromagnetic waves: the challenge of variability and the contribution of statistics to dosimetry (J. Wiart); 5 - status of knowledge about electromagnetic fields hyper-sensitivity (J.P. Marc-Vergnes); 6 - geno-toxicity of UV radiation: respective impact of UVB and UVA (T. Douki); 7 - National day of prevention and screening for skin cancers (F. Guibal); 8 - UV tan devices: status of knowledge about cancer risks (I. Tordjman, and J. Gaillot de Saintignon); 9 - In vitro study of the extremely low frequencies (ELF) effect on genes expression (J.F. Collard); 10 - modulation of brain activity during a tapping task after exposure to a 3000 {mu}T magnetic field at 60 Hz (M. Souques and A. Legros); 11 - calculation of ELF electromagnetic fields in the human body by the finite elements method (R. Scoretti); 12 - French population exposure to the 50 Hz magnetic field (I. Magne); 13 - LF and static fields, new ICNIRP recommendations: what has changed, what remains (B. Vey. Veyret); 14 - risk assessment of low energy lighting systems - DELs and CFLs (J.P. Cesarini); 15 - biological effects to the rat of a chronic exposure to high power microwaves (R. De Seze); 16 - theoretical and experimental electromagnetic compatibility approaches of active medical implants in the 10-50 Hz frequency range: the case of implantable cardiac defibrillators (J. Katrib); 17 - French physicians and electromagnetic fields (M. Souques). (J.S.)

  16. Study of consequences of a ionizing radiation exposure on the health of persons having stay at the Marie Curie school of Nogent-sur-Marne (Val-de-Marne); Etude des consequences d'une exposition aux rayonnements ionisants sur la sante des personnes ayant sejourne a l'ecole Marie Curie de Nogent-sur-Marne (Val-de-Marne)

    NONE

    2004-03-01

    This study follows two other ones about the same subject. No one could bring elements to the question of the exposure impact on the population having stayed in the school. The old pupils and personnel have been exposed to radiation doses higher to the limit values of public exposure especially before 1987. The scientific knowledge suggest that the eventual sanitary consequences are in the area of low risks. The lack of exhaustiveness in the inquiry realisation and the lack of statistical power did not allow to measure the sanitary impact of ionizing radiation exposure among the former pupils of the Marie Curie school of Nogent sur Marne. (N.C.)

  17. A value-critical assessment of the policy construction of hazard and risk for the safe use of ionising radiation

    Wallace, A.B.

    1993-01-01

    This paper presents a critique of the concept of ionising radiation safety policy from value perspectives that differ from those of the rationalist scientific. It attempts to present a social interpretation of the constitution of the present methods of policy composition that are primarily based on a conservative, orthodox, scientific paradigm. A modification of this process is then offered to integrate social discourse into the policy construction without compromising the value of the scientific input. 6 refs

  18. Ionising energy treatment for fresh horticultural produce -mandarins and other produce, Trials 1 and 2, May-July 1987

    McLauchlan, R.L.; Brown, B.I.; Mitchell, G.E.; Aston, J.W.; Wood, A.F.; Isaacs, A.R.; Williams, S.M.; Nottingham, S.M.; Wilson, P.R.; Juffs, H.S.; Johnson, G.I.; Heather, N.W.; Giles, J.E.; Wills, P.A.

    1988-01-01

    Two trials are described on the effect of ionising energy treatment, or irradiation, on the quality, shelf-life and composition of fresh produce, mainly at doses consistent with disinfestation treatment for quarantine purposes. Trial 1, carried out in May 1987, deals with replicated treatments of Imperial mandarins and preliminary observation treatments on a range of other produce. Trial 2 deals with replicated treatments of Ellendale mandarins and preliminary observation treatments on other produce

  19. Statutory Instruments No 144 of 1994. European Communities (Protection of outside workers from ionising radiation) Regulations, 1994

    1994-04-01

    These Regulations implement Council Directive 90/641 EURATOM of 4 December, 1990 on the operational protection of outside workers exposed to the risk of ionising radiation during their activities in controlled areas. The Regulations provide for the radiation protection of workers liable to receive an exposure of high radiation levels while working away from their employers' premises. The Regulations also apply to workers who come from, or who go to work in, another Member State of the European Community

  20. Beta-decay measurements of neutron-rich thallium, lead, and bismuth by means of resonant laser ionisation

    Franchoo, S.; de Witte, H.; Andreyev, A. N.; Cederka¨Ll, J.; Dean, S.; de Smet, A.; Eeckhaudt, S.; Fedorov, D. V.; Fedosseev, V. N.; G´Rska, M.; Huber, G.; Huyse, M.; Janas, Z.; Ko¨Ster, U.; Kurcewicz, W.; Kurpeta, J.; Mayer, P.; Płchocki, A.; van de Vel, K.; van Duppen, P.; Weissman, L.; Isolde Collaboration

    2004-04-01

    Neutron-rich thallium, lead, and bismuth isotopes were investigated at the ISOLDE facility. After mass separation and resonant laser ionisation of the produced activity, new spectroscopic data were obtained for 215,218Bi and 215Pb. An attempt to reach heavy thallium had to be abandoned because of a strong francium component in the beam that gave rise to a neutron background through (α,n) reactions on the aluminium walls of the experimental chamber.

  1. Rapid and simultaneous determination of polychlorinated biphenyls and their main metabolites (hydroxylated and methyl sulfonyl) by gas chromatography coupled to mass spectrometry: Comparison of different ionisation modes

    Castro-Puyana, M.; Herrero, L.; González, M.J.; Gómara, B.

    2013-01-01

    Graphical abstract: -- Highlights: •Simultaneous determination of PCB, OH-PCBs and MeSO 2 -PCBs in a single GC–MS run. •Two different ionisation modes (EI and ECNI) are studied and compared. •The analytical characterisation of both methods is satisfactory. •Better LODs are achieved using ECNI-MS as ionisation mode. •The developed methodology is successfully applied to fish liver oil. -- Abstract: Instrumental methods based on gas chromatography coupled to mass spectrometry (GC–MS) have been developed and compared using two different MS ionisation modes, electron impact (EI) and electron capture negative ionisation (ECNI), for the fast, quantitative and simultaneous determination of polychlorinated biphenyls (PCBs) and their main metabolites (hydroxylated PCBs, OH-PCBs, and methyl sulfone PCBs, MeSO 2 -PCBs). Parameters affecting chromatographic separation and MS detection were evaluated in order to achieve the highest selectivity and sensitivity for both operation modes. The analytical characteristics of the developed methods were studied and compared in terms of linear range, limits of detection (LODs), limits of quantification (LOQs), and instrumental precision (repeatability and intermediate precision). Both ionisation methods showed similar precision, being relative standard deviations (RSD, %) lower than 9% and 14% for repeatability and intermediate precision, respectively. However, better LODs (from 0.01 to 0.14 pg injected for the three families of congeners studied) were achieved using ECNI-MS as ionisation mode. The suitability of the developed method was demonstrated through their application to fish liver oil samples

  2. Simulation and measurements of the response of an air ionisation chamber exposed to a mixed high-energy radiation field

    Vincke, H.; Forkel-Wirth, D.; Perrin, D.; Theis, C.

    2005-01-01

    CERN's radiation protection group operates a network of simple and robust ionisation chambers that are installed inside CERN's accelerator tunnels. These ionisation chambers are used for the remote reading of ambient dose rate equivalents inside the machines during beam-off periods. This Radiation Protection Monitor for dose rates due to Induced Radioactivity ('PMI', trade name: PTW, Type 34031) is a non-confined air ionisation plastic chamber which is operated under atmospheric pressure. Besides its current field of operation it is planned to extend the use of this detector in the Large Hadron Collider to measure radiation under beam operation conditions to obtain an indication of the machine performance. Until now, studies of the PMI detector have been limited to the response to photons. In order to evaluate its response to other radiation components, this chamber type was tested at CERF, the high-energy reference field facility at CERN. Six PMI detectors were installed around a copper target being irradiated by a mixed hadron beam with a momentum of 120 GeV c -1 . Each of the chosen detector positions was defined by a different radiation field, varying in type and energy of the incident particles. For all positions, detailed measurements and FLUKA simulations of the detector response were performed. This paper presents the promising comparison between the measurements and simulations and analyses the influence of the different particle types on the resulting detector response. (authors)

  3. Control and calculation of the titanium sublimation pumping speed and re-ionisation in the MAST neutral beam injectors

    McAdams, R.

    2015-01-01

    Highlights: • The titanium sublimation pumps for the MAST neutral beam injectors are described. • Evaporation regimes are established to give constant pumping speed for the titanium sublimation pumps. • The MCNP code is used to calculate the pumping speeds and gas profiles in the neutral beam injectors. • The gas profiles are then used to calculate the level of re-ionisation in the beamline. - Abstract: A high pumping speed is required in neutral beam injectors to minimise re-ionisation of the neutral beams. The neutral beam injectors on MAST use titanium sublimation pumps. These pumps do not have a constant pumping speed; their pumping speed depends on the gettering surface history and on both the integrated and applied gas load. In this paper we describe a method of maintaining a constant pumping speed, through different evaporation schemes, specifically suitable for operations of the MAST neutral beam injector beamlines for both short and relatively long beam pulses by measurement of the pressure in the beamline. In addition the MCNP code is then used to calculate the pumping speed and gas profile in the beamline by adjusting the input pumping speed to match the measured pressure. This allows the resulting gas profile to be used for calculation of the re-ionisation levels and an example is given

  4. Molecular mechanisms of plant response to ionising radiation. Exploration of the glucosinolate role in the anti-oxidative response

    Gicquel, M.

    2012-01-01

    Terrestrial organisms are exposed to low doses of ionising radiation from natural or anthropogenic sources. The major effects of the radiations are due to DNA deterioration and water radiolysis which generates an oxidative stress by free radical production. Plants constitute good models to study the effects of ionising radiations and the search of antioxidant molecules because of their important secondary metabolism. Thus this thesis, funded by the Brittany region, characterized the physiological and molecular response of the model plant Arabidopsis thaliana to low (10 Gy) and moderate (40 Gy) doses of ionising radiation, and was therefore interested in glucosinolates, characteristic compounds of the Brassicaceae family. The global proteomic and transcriptomic studies carried out on this model revealed (1) a common response for both doses dealing with the activation of DNA repair mechanisms, cell cycle regulation and protection of cellular structures; (2) an adjustment of the energetic metabolism and an activation of secondary compounds biosynthesis (i.e. glucosinolates and flavonoids) after the 10 Gy dose; (3) an induction of enzymatic control of ROS, the regulation of cellular components recycling and of programmed cell death after the 40 Gy dose. The potential anti-oxidative role of glucosinolates was then explored. The in vitro anti-oxidative power of some glucosinolates and their derivative products were demonstrated. Their modulating effects against irradiation-induced damages were then tested in vivo by simple experimental approaches. The importance of the glucosinolate level to give a positive or negative effect was demonstrated. (author)

  5. FREQUENCY OF CHROMOSOMAL ABERRATIONS AND MICRONUCLEI IN HORSE LYMPHOCYTES FOLLOWING IN VITRO EXPOSURE TO LOW DOSE IONISING RADIATION

    Dunja Rukavina

    2012-07-01

    Full Text Available Ionising radiation is known to cause chromosomal instability, which is observed as increased frequency of chromosomal aberration and micronuclei. These are listed as reliable criteria in biological dosimetry. Numerous experiments conducted on both animal and plant models demonstrated that increase in radiation dosage is followed by increased mutation frequency, and that mutations occur even at the lowest exposure. We used horse blood in vitro irradiated by low doses of ionizing radiation. Cultivation of peripheral blood lymphocytes and micronucleus test were used as biomarkers of genetic damage. The observed aberrations were recorded and classified in accordance with the International System of Cytogenetic Nomenclature. Micronuclei were identified on the basis of criteria proposed by Fenech et al. (8. Analysis of chromosomal aberration showed increased frequency of aberrations in blood cultures exposed to 0,1 Gy and 0,2 Gy compared to the controls. Microscopic analysis of chromosomal damage in in vitro micronucleus test revealed that the applied radiation dose induced micronuclei while no binucleated cells with micronuclei were found in lymphocytes that were not irradiated. In this paper we analysed the influence of low dose ionising radiation on frequency of chromosomal aberration and micronuclei in horse lymphocytes following in vitro exposure to X-rays (0,1 Gy and 0,2 Gy. Key words: chromosomal aberrations, micronuclei, ionising radiation, horse lymphocytes

  6. Cancer mortality risk of nuclear power workers due to the exposure of ionising radiation in Germany

    Fehringer, F.; Seitz, G.; Hammer, G.P.; Blettner, M.

    2006-01-01

    A cohort study of German nuclear power workers was set up to investigate overall and cancer mortality risk related to a chronic exposure to ionising radiation of low-level dose. The German study was performed as a part of an international study carried out by the International Agency for Research on Cancer (IARC), Lyon. First results of the international study have been published recently [1]. German data are not yet included in this analysis. The German cohort consists of 4844 employees from 10 nuclear power plants. All persons who worked in these nuclear power plants in 1991 or started employment between 1991 und 1997 are included (except for employees of one plant, whose observation period started in 1992). These persons accumulated about 31,000 person years. Overall, 68 deaths were observed in the observation period between 1.1.1991-31.12.1997. Standardized mortality ratios (SMR) were computed for all causes of death, all cancers, cardiovascular diseases, external causes, and all other causes. Overall, a strong healthy worker effect was observed (SMR=0.52 [95% CI: 0.41;0.67]). No increase in total cancer mortality was seen (SMR=0.85 [95% CI: 0.53;1.30]). However, numbers are too small for stable risk estimates and further effort is under way to complete the cohort in terms of power plants and to extend the follow-up until 2005. (authors)

  7. Nailfold Capillaroscopic Monitoring as Preventive Medicine in Subjects Exposed to Ionising Radiation

    Pennarola, R.; Perdereau, B.; Trenta, G.; Cosset, J. M.

    2004-01-01

    Capillaroscopy consists of in vivo observation of microvessels using special microscopes with a short focal length. Normally, when looking at the nail fold, where capillaroscopy is commonly used, the capillaries ares arranged like hairpins, lined up in parallel or obliquely to the field of vision in three or four layers above the subpapillary venous network, approximately 20 loops per mm''2. Ionising radiation can badly damage the skin and underlying tissues. The capillary network is among the first structures to show an effect. Moderate doses of radiation cause damage endothelial cells with hypertrophy or hyperplasia of endothelial cells, which can block capillaries while having little effect on larger vessels. Occlusion of capillaries impedes blood flow no only in nearby tissue but also in areas farther away. Capillaroscopic examination of the nail fold is irreplaceable in the field of radioprotection especially in cases of exposure of the hands. Nailfold capillaroscopic monitoring lets us observe the degree to which qualitative and quantitative alterations of the capillaries are a function of the evolution of the lesion. Therefore, for biological monitoring of subjects exposed to radiation the authors propose to use this microvascular quantitative analysis of the nailfold region. Experience, matured over many years by our team, highlights the relation between the sum of repeated exposure and the importance of tissue alterations evidenced by microcirculation. (Author) 9 refs

  8. The use of caffeine to assess high dose exposures to ionising radiation by dicentric analysis

    Pujol, M.; Puig, R.; Caballin, M. R.; Barrios, L.; Barquinero, J. F.

    2012-01-01

    Dicentric analysis is considered as a 'gold standard' method for biological dosimetry. However, due to the radiation-induced mitotic delay or inability to reach mitosis of heavily damaged cells, the analysis of dicentrics is restricted to doses up to 4-5 Gy. For higher doses, the analysis by premature chromosome condensation technique has been proposed. Here, it is presented a preliminary study is presented in which an alternative method to analyse dicentrics after high dose exposures to ionising radiation (IR) is evaluated. The method is based on the effect of caffeine in preventing the G2/M checkpoint allowing damaged cells to reach mitosis. The results obtained indicate that the co-treatment with Colcemide and caffeine increases significantly increases the mitotic index, and hence allows a more feasible analysis of dicentrics. Moreover in the dose range analysed, from 0 to 15 Gy, the dicentric cell distribution followed the Poisson distribution, and a simulated partial-body exposure has been clearly detected. Overall, the results presented here suggest that caffeine has a great potential to be used for dose-assessment after high dose exposure to IR. (authors)

  9. Framework for the Protection of the Environment from Ionising Radiation (invited paper)

    Strand, P.; Brown, J.E.; Larsson, M

    2000-07-01

    A framework is proposed for the protection of the environment from ionising radiation. Key components include the assessment of the environmental transfer of radionuclides and uptake of radionuclides by organisms, the adaptation of existing dosimetric models to calculate absorbed doses and studies concerning dose-effects relationships for selected organisms. The proposed framework will also make use of 'reference' organisms, selection of which will be based on a number of criteria, e.g. radiosensitivity, ubiquity, and will involve the development of standardised biota exposure units which might integrate the Relative Biological Effect (RBE) of the radiation under consideration. In the second part of the study, initial efforts have been made to develop a computerised system in order to provide a simple example of how components of this framework may be formulated. An equilibrium absorbed dose constant model has been used for high LET (Linear Energy Transfer) radionuclides combined with the application of an absorbed fraction for {gamma}-emitting radionuclides. Generalised specific activity information for selected radionuclides from Norwegian marine environments have been used as model input data. For the radionuclides considered, total doses for marine organisms (lobster, mussels, seaweed) ranged between 1.35-2.5 mGy.y{sup -1}, mainly attributable to {sup 40}K and {sup 210}Po. Such levels are well below those where observable effects might be expected. (author)

  10. Impact of chronic, low-level ionising radiation exposure on terrestrial invertebrates

    Hingston, J.; Wood, M.D.; Copplestone, D.; Zinger, I. [Liverpool Univ., School of Biological Sciences, Merseyside (United Kingdom)

    2004-07-01

    There is a need to confirm that the environment is being adequately protected from the mixture of contaminants released into it. In the field of environmental radioactivity, tools have been developed to assess the impacts of ionising radiation on wildlife. The scientific data upon which these assessments are based is, however, lacking. New documentation has been produced by the UK Environment Agency to provide guidelines on structuring experiments (using environmentally relevant doses) and select suitable non-human species and endpoints for study. It is anticipated that this documentation will be used to direct future experiments in this field. This paper presents the results of the first of these experiments. Numbers of the earthworm Eisenia fetida and the wood louse Porcellio scaber were segregated and constantly exposed to one of six radiation doses (background, 0.1, 0.4, 1.5, 4.0 and 8.0 mGyh{sup -1}) for a total of 16 and 14 weeks respectively. The endpoints of mortality, number of viable offspring and average weight of an individual were recorded and the results of this study will be discussed here. (author)

  11. Effect of penetrating ionising radiation on the mechanical properties of pericardium

    Daar, Eman, E-mail: e.daar@surrey.ac.u [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Woods, E. [Royal Free Hampstead NHS Trust, Pond Street, Hampstead, London NW3 2QG (United Kingdom); Keddie, J.L. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Nisbet, A. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Royal Surrey County Hospital, Guildford (United Kingdom); Bradley, D.A. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom)

    2010-07-21

    The pericardium is an anistropic composite material made up of collagen and elastin fibres embedded in an amorphous matrix mainly composed of proteoglycan and hyaluronan. The collagen fibres are arranged in layers, with different directions of alignment in each layer, giving rise to interesting mechanical properties of pericardium, including the ability to undergo large deformation during performance of regular physiological functions. The present study aims to investigate the effect of penetrating photon ionising radiation on bovine pericardium tissue, being part of a study of the effect of cardiac doses received in breast radiotherapy and the possibility that this can give rise to cardiovascular complications. Irradiation doses in the range 5-80 Gy were used. To characterise the various mechanical properties [elastic modulus, stress relaxation, ultimate tensile strength (UTS) and fracture] a uniaxial tensile test method was applied. The preliminary results reflect the wide inter-sample variations that are expected in dealing with tissues, with only a weak indication of increase in the UTS of the pericardium tissue with increase in radiation dose. Such an effect has also been observed by others, with reduction in UTS at doses of 80 Gy.

  12. The Assessment of DNA Damage in Poultry Spermatozoa after Exposure to Low Doses of Ionising Radiation

    Kasuba, V.; Milic, M.; Pejakovic Hlede, J.; Gottstein, Z.; Karadjole, M.; Miljanic, S.

    2013-01-01

    The existence of dose-related induction of DNA strand breaks in spermatozoa following in vitro exposure to ionising radiation represents sperm DNA integrity as an important parameter in the evaluation of semen functionality. Maintaining of normal sperm becomes even more important when it is known that DNA in semen samples is already fragmentated in certain amount in human and turkey semen and that it lacks DNA repair mechanisms making DNA damage irreversible. The aim of this paper was to provide an insight in the amount of DNA damage detected in chicken spermatozoa (5 cocks, 45 weeks old) of heavy line after radiation with doses of 0.3, 0.5, 1 and 2 Gy gamma radiation and to address the question of the potential ecological consequences of the damage that was measured with comet assay. Scored parameters included tail intensity, tail length and tail moment. Results showed sensitivity of comet assay technique that detected significant DNA damage even after exposure to 0.3 Gy, but also showed no dose-related responses after 0.5, 1 and 2 Gy. Distribution of damaged cells was widely spread for the higher doses, showing the influence of possible adaptive response, but for further conclusions, larger studies are needed to answer that question.(author)

  13. Cancer mortality risk of nuclear power workers due to the exposure of ionising radiation in Germany

    Fehringer, F.; Seitz, G. [Berufsgenossenschaft der Feinmechanik und Elektrotechnik, Koln (Germany); Hammer, G.P.; Blettner, M. [Johannes Gutenberg-Universitat Mainz, Institut fur Medizinische Biometrie, Epidemiologie und Informatik des Klinikums (Germany)

    2006-07-01

    A cohort study of German nuclear power workers was set up to investigate overall and cancer mortality risk related to a chronic exposure to ionising radiation of low-level dose. The German study was performed as a part of an international study carried out by the International Agency for Research on Cancer (IARC), Lyon. First results of the international study have been published recently [1]. German data are not yet included in this analysis. The German cohort consists of 4844 employees from 10 nuclear power plants. All persons who worked in these nuclear power plants in 1991 or started employment between 1991 und 1997 are included (except for employees of one plant, whose observation period started in 1992). These persons accumulated about 31,000 person years. Overall, 68 deaths were observed in the observation period between 1.1.1991-31.12.1997. Standardized mortality ratios (SMR) were computed for all causes of death, all cancers, cardiovascular diseases, external causes, and all other causes. Overall, a strong healthy worker effect was observed (SMR=0.52 [95% CI: 0.41;0.67]). No increase in total cancer mortality was seen (SMR=0.85 [95% CI: 0.53;1.30]). However, numbers are too small for stable risk estimates and further effort is under way to complete the cohort in terms of power plants and to extend the follow-up until 2005. (authors)

  14. Application of positive mode atmospheric chemical ionisation to distinguish epimeric oleanolic and ursolic acids.

    Townley, Chloe; Brettell, Rhea C; Bowen, Richard D; Gallagher, Richard T; Martin, William H C

    2015-01-01

    A new and more reliable method is reported for distinguishing the equatorial and axial epimers of oleanolic and ursolic acids and related triterpenoids based primarily on the relative abundance of the [M+H](+) and [M+-H(2)O](+) signals in their positive mode atmospheric pressure chemical ionisation mass spectra. The rate of elimination of water, which is the principal primary fragmentation of protonated oleanolic and ursolic acids, depends systematically on the stereochemistry of the hydroxyl group in the 3 position. For the b-epimer, in which the 3-hydroxyl substituent is in an equatorial position,[M+-H(2)O](+) is the base peak. In contrast, for the α-epimer, where the 3-hydroxyl group is axial, [M + H](+) is the base peak. This trend, which is general for a range of derivatives of oleanolic and ursolic acids, including the corresponding methyl esters, allows epimeric triterpenoids in these series to be securely differentiated. Confirmatory information is available from the collision-induced dissociation of the [M+-H(2)O](+) primary fragment ions, which follow different pathways for the species derived from axial and equatorial epimers of oleanolic and ursolic acids. These two pieces of independent spectral information permit the stereochemistry of epimeric oleanolic and ursolic acids (and selected derivatives) to be assigned with confidence without relying either on chromatographic retention times or referring to the spectra or other properties of authentic samples of these triterpenoids.

  15. A gas ionisation Direct-STIM detector for MeV ion microscopy

    Norarat, Rattanaporn; Guibert, Edouard; Jeanneret, Patrick; Dellea, Mario; Jenni, Josef; Roux, Adrien; Stoppini, Luc; Whitlow, Harry J.

    2015-01-01

    Direct-Scanning Transmission Ion Microscopy (Direct-STIM) is a powerful technique that yields structural information in sub-cellular whole cell imaging. Usually, a Si p-i-n diode is used in Direct-STIM measurements as a detector. In order to overcome the detrimental effects of radiation damage which appears as a broadening in the energy resolution, we have developed a gas ionisation detector for use with a focused ion beam. The design is based on the ETH Frisch grid-less off-axis Geiger–Müller geometry. It is developed for use in a MeV ion microscope with a standard Oxford Microbeams triplet lens and scanning system. The design has a large available solid angle for other detectors (e.g. proton induced fluorescence). Here we report the performance for imaging ReNcells VM with μm resolution where energy resolutions of <24 keV fwhm could be achieved for 1 MeV protons using isobutane gas

  16. Genotoxicity in earthworm after combined treatment of ionising radiation and mercury

    Ryu, Tae Ho; Kim, Jin Kyu; An, Kwang-Guk

    2014-01-01

    This study was performed to investigate the acute genotoxic effects of mercury and radiation on earthworms (Eisenia fetida). The levels of DNA damage and the repair kinetics in the coelomocytes of E. fetida treated with mercuric chloride (HgCl 2 ) and ionising radiation (gamma rays) were analysed by means of the comet assay. For detection of DNA damage and repair, E. fetida was exposed to HgCl 2 (0-160 mg kg -1 ) and irradiated with gamma rays (0-50 Gy) in vivo. The increase in DNA damage depended on the concentration of mercury or dose of radiation. The results showed that the more the oxidative stress induced by mercury and radiation the longer the repair time that was required. When a combination of HgCl 2 and gamma rays was applied, the cell damage was much higher than those treated with HgCl 2 or radiation alone, which indicated that the genotoxic effects were increased after the combined treatment of mercury and radiation. (authors)

  17. Analysis of e-e angular correlations in near-threshold electron impact ionisation of helium

    Selles, P.; Huetz, A.; Mazeau, J.

    1987-01-01

    Using a coincidence technique in a coplanar geometry, triple differential cross sections (TDCS) for electron impact ionisation of helium are measured in the 0.5-2 eV energy range above threshold. As a few states (O <= L <= 2) of the two outgoing electrons are obviously involved in the process, their respective intensities appear as unknown parameters in the theoretical TDCS as deduced in the frame of the Wannier theory. The authors show that almost all these parameters can be determined through normalisation to the measured TDCS in two specific geometries: in the first one the two electrons are kept in opposite directions while in the second one they remain symmetrical with respect to the incident beam. A comparison with the complete set of data is then performed. The measured TDCS are in agreement with the Wannier theory for the lowest energies (0.5 and 1 eV). At 2 eV the overall agreement becomes poorer, although some predictions of the Wannier theory still apply. Finally specific measurements at 8 eV clearly show from consideration of symmetry that the Wannier theory no longer applies at this energy. (author)

  18. Gene expression analysis after low dose ionising radiation exposure of the developing organism

    Abderrafi Benotmane, M.

    2007-01-01

    Measuring gene expression using microarrays is relevant to many areas of biology and medicine, such as follow up of developmental stages and diseases onset, and treatment study. Since there can be tens of thousands of distinct probes on an array, each micro array experiment can accomplish the equivalent number of genetic tests in parallel. Arrays have therefore dramatically accelerated many types of investigations. For example, microarrays can be used to identify stress response genes by comparing gene expression in challenged versus normal cells. In the Molecular and Cellular Biology lab (MCB), the micro array experiments are performed within the Genomic Platform, fully equipped to analyse either the behaviour of bacteria during long space flight, the effect of low dose ionising radiation on the developing organism in mice, or the human individual radiation sensitivity. For the low dose effect, two main stages of development are of interest; 1) the gastrula stage at which ionizing radiation can induce several malformations. 2) the organogenesis. During brain development, epidemiological studies of the atomic bomb survivors of Hiroshima/Nagasaki showed increased risk of mental retardation in children of women exposed between weeks 8-15 of pregnancy or at a lower extend between weeks 15 to 25

  19. Genomic instability in rat: Breakpoints induced by ionising radiation and interstitial telomeric-like sequences

    Camats, Nuria; Ruiz-Herrera, Aurora; Parrilla, Juan Jose; Acien, Maribel; Paya, Pilar; Giulotto, Elena; Egozcue, Josep; Garcia, Francisca; Garcia, Montserrat

    2006-01-01

    The Norwegian rat (Rattus norvegicus) is the most widely studied experimental species in biomedical research although little is known about its chromosomal structure. The characterisation of possible unstable regions of the karyotype of this species would contribute to the better understanding of its genomic architecture. The cytogenetic effects of ionising radiation have been widely used for the study of genomic instability, and the importance of interstitial telomeric-like sequences (ITSs) in instability of the genome has also been reported in previous studies in vertebrates. In order to describe the unstable chromosomal regions of R. norvegicus, the distribution of breakpoints induced by X-irradiation and ITSs in its karyotype were analysed in this work. For the X-irradiation analysis, 52 foetuses (from 14 irradiated rats) were studied, 4803 metaphases were analysed, and a total of 456 breakpoints induced by X-rays were detected, located in 114 chromosomal bands, with 25 of them significantly affected by X-irradiation (hot spots). For the analysis of ITSs, three foetuses (from three rats) were studied, 305 metaphases were analysed and 121 ITSs were detected, widely distributed in the karyotype of this species. Seventy-six percent of all hot spots analysed in this study were co-localised with ITSs

  20. Genomic instability in rat: Breakpoints induced by ionising radiation and interstitial telomeric-like sequences

    Camats, Nuria [Institut de Biotecnologia i Biomedicina (IBB), Universitat Autonoma de Barcelona, 08193 Barcelona (Spain); Departament de Biologia Cel.lular, Fisiologia i Immunologia Universitat Autonoma de Barcelona, 08193 Barcelona (Spain); Ruiz-Herrera, Aurora [Departament de Biologia Cel.lular, Fisiologia i Immunologia Universitat Autonoma de Barcelona, 08193 Barcelona (Spain); Parrilla, Juan Jose [Servicio de Ginecologia y Obstetricia, Hospital Universitario Virgen de la Arrixaca, Ctra, Madrid-Cartagena, s/n, El Palmar, 30120 Murcia (Spain); Acien, Maribel [Servicio de Ginecologia y Obstetricia, Hospital Universitario Virgen de la Arrixaca, Ctra, Madrid-Cartagena, s/n, El Palmar, 30120 Murcia (Spain); Paya, Pilar [Servicio de Ginecologia y Obstetricia, Hospital Universitario Virgen de la Arrixaca, Ctra, Madrid-Cartagena, s/n, El Palmar, 30120 Murcia (Spain); Giulotto, Elena [Dipartimento di Genetica e Microbiologia Adriano Buzzati Traverso, Universita degli Studi di Pavia, 27100 Pavia (Italy); Egozcue, Josep [Departament de Biologia Cel.lular, Fisiologia i Immunologia Universitat Autonoma de Barcelona, 08193 Barcelona (Spain); Garcia, Francisca [Institut de Biotecnologia i Biomedicina (IBB), Universitat Autonoma de Barcelona, 08193 Barcelona (Spain); Garcia, Montserrat [Institut de Biotecnologia i Biomedicina (IBB), Universitat Autonoma de Barcelona, 08193 Barcelona (Spain) and Departament de Biologia Cellular, Fisiologia i Immunologia Universitat Autonoma de Barcelona, 08193 Barcelona (Spain)]. E-mail: Montserrat.Garcia.Caldes@uab.es

    2006-03-20

    The Norwegian rat (Rattus norvegicus) is the most widely studied experimental species in biomedical research although little is known about its chromosomal structure. The characterisation of possible unstable regions of the karyotype of this species would contribute to the better understanding of its genomic architecture. The cytogenetic effects of ionising radiation have been widely used for the study of genomic instability, and the importance of interstitial telomeric-like sequences (ITSs) in instability of the genome has also been reported in previous studies in vertebrates. In order to describe the unstable chromosomal regions of R. norvegicus, the distribution of breakpoints induced by X-irradiation and ITSs in its karyotype were analysed in this work. For the X-irradiation analysis, 52 foetuses (from 14 irradiated rats) were studied, 4803 metaphases were analysed, and a total of 456 breakpoints induced by X-rays were detected, located in 114 chromosomal bands, with 25 of them significantly affected by X-irradiation (hot spots). For the analysis of ITSs, three foetuses (from three rats) were studied, 305 metaphases were analysed and 121 ITSs were detected, widely distributed in the karyotype of this species. Seventy-six percent of all hot spots analysed in this study were co-localised with ITSs.

  1. Changes in amino transferases and muscle proteins when treating pigmeat with ionising rays

    Hamm, R; Hofmann, K; Gruenewald, T; Partmann, W [Bundesanstalt fuer Fleischforschung, Kulmbach (F.R. Germany). Inst. fuer Chemie und Physik; Bundesforschungsanstalt fuer Ernaehrung, Karlsruhe [F.R. Germany

    1975-01-01

    Slices of lean pigmeat were treated with electron beams doses of 0.2, 1.0 and 5.0 Mrad. Low irradiation doses led to an increase in the activity of aspartate amino transferase (GOT) and alanin amino transferase (GPT) in the tissue generally and in the sarcoplasm (juice expressed from the muscle). 5 Mrad caused a great reduction in the activity of GOT and GPT in the tissue and the sarcoplasm. It seems doubtful whether this inactivation is due to a destruction of enzyme sulphhydryl groups. Irradiating with 5 Mrad resulted in partial release of the mitochondrial GOT isozyme (GOTsub(M)) into the sarcoplasm. This indicates damage to the mitochondrial membranes by ionising radiation. Irradiating the pigmeat increased the pH of the tissue and lowered its water binding ability (increase in drip). Up to a dose of 1 Mrad the solubility of the sarcoplasmic proteins was not definitely affected, but 5 Mrad caused a considerable drop in protein solubility. Surprisingly a dose of even 5 Mrad did not change the total number of sulphhydryl groups present in the tissue. Sephadex thin layer electrophoresis showed that at 0.2 Mrad there was a drastic decrease in the myosin band and an increase in peptide fragments of low molecular weight, whilst actin was little changed.

  2. Determination of fluspirilene in human plasma by liquid chromatography-tandem mass spectrometry with electrospray ionisation.

    Swart, K J; Sutherland, F C; van Essen, G H; Hundt, H K; Hundt, A F

    1998-12-18

    An ultra-sensitive method for the determination of fluspirilene in plasma was established, using high-performance liquid chromatographic separation with tandem mass spectrometric detection. The samples were extracted with hexane/isoamyl alcohol, separated on a Phenomenex Luna C18 5 mu 150 x 2.1 mm column with a mobile phase consisting of methanol-water-acetic acid (600:400:1) at a flow-rate of 0.3 ml/min. Detection was achieved by a Finnigan Matt mass spectrometer (LCQ) at unit resolution in full scan mode scanning the product ion spectrum from m/z 130-500 and monitoring the transition of the protonated molecular ion at m/z 476.2, to the sum of the largest product ions m/z 371, 342 and 274 (MS-MS). Electrospray ionisation was used for ion production. The mean recovery for fluspirilene was 90% with a lower limit of quantification of 21.50 pg/ml using 1 ml plasma for extraction. This is the first chromatographic method described for the determination of fluspirilene in plasma that is accurate and sensitive enough to be used in pharmacokinetic studies.

  3. The study of some thiazinic and indaminic dye syntheses induced by ionising radiation

    Balestic, S.

    1961-03-01

    With a view to finding some radiochemical reactions applicable on an industrial scale for evaluating the radioactive waste from nuclear reactors, a systematic study was made of the radiochemical synthesis of thiazinic dyes such as methylene blue and Lauths' violet, on which the first tests were carried out in 1954. The first part of the study concerned the identification and the dosage, during radiolysis, of dyes by means of their absorption spectra after separation from the reaction medium by adsorption chromatography or ion-exchange; other radiolysis products such as ammonium chloride and hydrogen peroxide were also identified. During a later stage by systematically varying the physico-chemical parameters it was possible to determine the most favourable conditions for radio-synthesis; the maximum radiochemical yields obtained had the following values: G (Lauths' violet) 1,65; G (Methylene blue) = 1,75. Furthermore, the study of the influence of variously substituted aminated products on the radiochemical yield showed the possibility of synthesising Bindsehedlers green and Wursters blue by radiochemical methods. Finally the discovery of a fundamental intermediate product, Wursters red, together with the kinetic study of the chemical synthesis of methylene blue made it possible to determine the main stages of the reaction mechanism and to decide which of these stages could be attributed to ionising radiations in the case of the radiochemical synthesis. (author) [fr

  4. The risk of low doses of ionising radiation and the linear no threshold relationship debate

    Tubiana, M.; Masse, R.; Vathaire, F. de; Averbeck, D.; Aurengo, A.

    2007-01-01

    The ICRP and the B.E.I.R. VII reports recommend a linear no threshold (L.N.T.) relationship for the estimation of cancer excess risk induced by ionising radiations (IR), but the 2005 report of Medicine and Science French Academies concludes that it leads to overestimate of risk for low and very low doses. The bases of L.N.T. are challenged by recent biological and animal experimental studies which show that the defence against IR involves the cell microenvironment and the immunologic system. The defence mechanisms against low doses are different and comparatively more effective than for high doses. Cell death is predominant against low doses. DNA repairing is activated against high doses, in order to preserve tissue functions. These mechanisms provide for multicellular organisms an effective and low cost defence system. The differences between low and high doses defence mechanisms are obvious for alpha emitters which show several greys threshold effects. These differences result in an impairment of epidemiological studies which, for statistical power purpose, amalgamate high and low doses exposure data, since it would imply that cancer IR induction and defence mechanisms are similar in both cases. Low IR dose risk estimates should rely on specific epidemiological studies restricted to low dose exposures and taking precisely into account potential confounding factors. The preliminary synthesis of cohort studies for which low dose data (< 100 mSv) were available show no significant risk excess, neither for solid cancer nor for leukemias. (authors)

  5. A dual-phase xenon TPC for scintillation and ionisation yield measurements in liquid xenon

    Baudis, Laura; Biondi, Yanina; Capelli, Chiara; Galloway, Michelle; Kazama, Shingo; Kish, Alexander; Pakarha, Payam; Piastra, Francesco; Wulf, Julien

    2018-05-01

    A small-scale, two-phase (liquid/gas) xenon time projection chamber ( Xurich II) was designed, constructed and is under operation at the University of Zürich. Its main purpose is to investigate the microphysics of particle interactions in liquid xenon at energies below 50 keV, which are relevant for rare event searches using xenon as target material. Here we describe in detail the detector, its associated infrastructure, and the signal identification algorithm developed for processing and analysing the data. We present the first characterisation of the new instrument with calibration data from an internal ^83{m} Kr source. The zero-field light yield is 15.0 and 14.0 photoelectrons/keV at 9.4 and 32.1 keV, respectively, and the corresponding values at an electron drift field of 1 kV/cm are 10.8 and 7.9 photoelectrons/keV. The charge yields at these energies are 28 and 31 electrons/keV, with the proportional scintillation yield of 24 photoelectrons per one electron extracted into the gas phase, and an electron lifetime of 200 μ s. The relative energy resolution, σ /E, is 11.9 and 5.8% at 9.4 and 32.1 keV, respectively using a linear combination of the scintillation and ionisation signals. We conclude with measurements of the electron drift velocity at various electric fields, and compare these to literature values.

  6. Changes in amino transferases and muscle proteins when treating pigmeat with ionising rays

    Hamm, R.; Hofmann, K.; Gruenewald, T.; Partmann, W.

    1975-01-01

    Slices of lean pigmeat were treated with electron beams doses of 0.2, 1.0 and 5.0 Mrad. Low irradiation doses led to an increase in the activity of aspartate amino transferase (GOT) and alanin amino transferase (GPT) in the tissue generally and in the sarcoplasm (juice expressed from the muscle). 5 Mrad caused a great reduction in the activity of GOT and GPT in the tissue and the sarcoplasm. It seems doubtful whether this inactivation is due to a destruction of enzyme sulphhydryl groups. Irradiating with 5 Mrad resulted in partial release of the mitochondrial GOT isozyme (GOTsub(M)) into the sarcoplasm. This indicates damage to the mitochondrial membranes by ionising radiation. Irradiating the pigmeat increased the pH of the tissue and lowered its water binding ability (increase in drip). Up to a dose of 1 Mrad the solubility of the sarcoplasmic proteins was not definitely affected, but 5 Mrad caused a considerable drop in protein solubility. Surprisingly a dose of even 5 Mrad did not change the total number of sulphhydryl groups present in the tissue. Sephadex thin layer electrophoresis showed that at 0.2 Mrad there was a drastic decrease in the myosin band and an increase in peptide fragments of low molecular weight, whilst actin was little changed. (orig.) [de

  7. Performance characteristics of a Bioassay method for plutonium using thermal ionisation mass spectrometry (TIMS)

    Linauskas, S.H.; Elliot, N.L.; Paterson, L.M.; Totland, M.M

    2003-01-01

    Plutonium-in-urine analysis by radiochemical isolation of Pu followed by thermal ionisation mass spectrometry (TIMS) is capable of high sensitivity and precision measurements {sup 239}Pu and {sup 240}Pu. Bias and precision estimates for the TIMS bioassay program at Chalk River Laboratories easily met the ANSI N13.30 performance criteria standards with {sup 239}Pu results of 1.5% and 3.0%, respectively. Analytical blanks derived from water, artificial urine and true urine samples did not produce any statistically different results. During a four-year period of development and implementation of {sup 239}Pu measurements by TIMS, average sample blank values were reduced from 3.9 fg (9.0 {mu}Bq) to 0.57 fg (1.3 {mu}Bq). This reduction was achieved through rigorous application of clean-room handling techniques throughout sample processing. Blank data were found to follow a Iognormal distribution, and current detection limit parameters for L{sub c} and L{sub d} at the 95% significance levels are 0.85 fg {sup 239}Pu (2.0 {mu}Bq) and 1.3 fg {sup 239}Pu (3.0 {mu}Bq), respectively. Detection limits in this range are expected to be sufficient to identify intakes of Pu/Am mixtures at levels that are around one-twentieth of an ALl or better under routine monitoring situations for ICRP Type S and Type M inhalation solubility classes. (author)

  8. Law on protection against ionising radiation and nuclear safety in Slovenia

    Breznik, B.; Krizman, M.; Skrk, D.; Tavzes, R.

    2003-01-01

    The existing legislation related to nuclear and radiation safety in Slovenia was introduced in 80's. The necessity for the new law is based on the new radiation safety standards (ICRP 60) and the intention of Slovenia to harmonize the legislation with the European Union. The harmonization means adoption of the basic safety standards and other relevant directives and regulations of Euratom. The nuclear safety section of this law is based on the legally binding international conventions ratified by Slovenia. The general approach is similar to that of some members of Nuclear Energy Agency (OECD). The guidelines of the law were set by the Ministry of the Environment and Spatial Planning, Nuclear Safety Administration, and Ministry of Health. The expert group of the Ministry of Environment and Spatial Planning and the Ministry of Health together with the representatives of the users of the ionising sources and representatives of the nuclear sector, prepared the draft of the subject law. The emphasis in this paper is given to main topics and solutions related to the control of the occupationally exposed workers, radiation safety, licensing, nuclear and waste safety, and radiation protection of people and patients. (authors)

  9. A special ionisation chamber for quality control of diagnostic and mammography X ray equipment

    Costa, A.M.; Caldas, L.V.E.

    2003-01-01

    A quality control program for X ray equipment used for conventional radiography and mammography requires the constancy check of the beam qualities in terms of the half-value layers. In this work, a special double-faced parallel-plate ionisation chamber was developed with inner electrodes of different materials, in a tandem system. Its application will be in quality control programs of diagnostic and mammography X ray equipment for confirmation of half-value layers previously determined by the conventional method. Moreover, the chamber also may be utilised for measurements of air kerma values (and air kerma rates) in X radiation fields used for conventional radiography and mammography. The chamber was studied in relation to the characteristics of saturation, ion collection efficiency, polarity effects, leakage current, and short-term stability. The energy dependence in response of each of the two faces of the chamber was determined over the conventional radiography and mammography X ray ranges (unattenuated beams). The different energy responses of the two faces of the chamber allowed the formation of a tandem system useful for the constancy check of beam qualities. (author)

  10. A special ionisation chamber for quality control of diagnostic and mammography X ray equipment.

    Costa, A M; Caldas, L V E

    2003-01-01

    A quality control program for X ray equipment used for conventional radiography and mammography requires the constancy check of the beam qualities in terms of the half-value layers. In this work, a special double-faced parallel-plate ionisation chamber was developed with inner electrodes of different materials, in a tandem system. Its application will be in quality control programs of diagnostic and mammography X ray equipment for confirmation of half-value layers previously determined by the conventional method. Moreover, the chamber also may be utilised for measurements of air kerma values (and air kerma rates) in X radiation fields used for conventional radiography and mammography. The chamber was studied in relation to the characteristics of saturation, ion collection efficiency, polarity effects, leakage current, and short-term stability. The energy dependence in response of each of the two faces of the chamber was determined over the conventional radiography and mammography X ray ranges (unattenuated beams). The different energy response of the two faces of the chamber allowed the formation of a tandem system useful for the constancy check of beam qualities.

  11. Revisiting Bragg's X-ray microscope: Scatter based optical transient grating detection of pulsed ionising radiation

    Fullagar, Wilfred K.; Paganin, David M.; Hall, Chris J.

    2011-01-01

    Transient optical gratings for detecting ultrafast signals are routine for temporally resolved photochemical investigations. Many processes can contribute to the formation of such gratings; we indicate use of optically scattering centres that can be formed with highly variable latencies in different materials and devices using ionising radiation. Coherent light scattered by these centres can form the short-wavelength-to-optical-wavelength, incoherent-to-coherent basis of a Bragg X-ray microscope, with inherent scope for optical phasing. Depending on the dynamics of the medium chosen, the way is open to both ultrafast pulsed and integrating measurements. For experiments employing brief pulses, we discuss high-dynamic-range short-wavelength diffraction measurements with real-time optical reconstructions. Applications to optical real-time X-ray phase-retrieval are considered. -- Research highlights: → It is timely that the concept of Bragg's X-ray microscope be revisited. → Transient gratings can be used for X-ray all-optical information processing. → Applications to optical real-time X-ray phase-retrieval are considered.

  12. Regulations concerning radiation protection and survey; Donnees de la surveillance et regles qui en resultent en matiere de protection contre les rayonnements

    Duhamel,; Lavie,; Fitoussi, [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    will only be considered with regard to recuperation of uranium after simple machining. (author) [French] 1. L'utilisation croissante de l'energie nucleaire sous toutes ses formes a des fins pacifiques pose des problemes de securite vis-a-vis des travailleurs, des populations et des sites en general. Une etude comparee des risques d'irradiation auxquels le personnel du Commissariat a l'Energie atomique (CEA) a ete expose au cours de l'annee 1957 et des resultats du controle des radiations par les moyens de detection collectifs ou individuels montre que les installations du CEA ont une influence negligeable sur la sante, en raison de la surveillance exercee. 2. Cependant, quelques incidents de contamination et d'irradiation - sommairement indiques ainsi que la maniere dont ils ont ete regles - rendent necessaire l'elaboration d'une reglementation precise definissant les responsabilites respectives, au sein d'un etablissement nucleaire, des services utilisateurs et du Service charge de la Protection contre les Radiations, en matiere de prevention de la contamination. 3. Un ensemble coherent de regles pratiques de prevention et de protection relatives a la detention, la manipulation, le transport et le stockage de sources radioactives scellees ou non scellees, est presente. A cette fin, a partir des recommandations de la Commission Internationale de Protection Radiologique et compte tenu: - de leur nocivite radioactive; de leur activite specifique par unite de masse et du risque de contamination; les radioelements ont ete classes suivant le danger qu'ils presentent par rapport au plutonium. 4. Le Service charge de la Protection contre les Radiations intervient comme conseiller des la conception des laboratoires specialises et veille ensuite a ce que les prescriptions reglementaires de securite soient observees. 5. Des donnees elaborees, indispensables a la protection contre les rayonnements, sont mises a la disposition des utilisateurs en particulier: - table des radio

  13. The Design of Diagnostic Medical Facilities where Ionising Radiation is used

    Malone, J.; O'Reilly, G.; O'Connor, U.; Gallagher, A.; Sheahan, N.; Fennell, S.

    2009-06-01

    The original Code of Practice on The Design of Diagnostic Medical Facilities Using Ionising Radiation was first published by the Nuclear Energy Board in 1988. In the intervening years the 'Blue Book' as it became known has served the medical community well as the sector has expanded and modernised and the late Dr Noel Nowlan, then Chief Executive of the Nuclear Energy Board, deserves much credit for initiating this pioneering contribution to radiation safety in Ireland. There have been significant developments since its publication in terms of the underlying radiation protection legislation, regulatory practice as well as developments in new technologies that have given rise to the need for a revision of the Code. This revised Code is based on a comprehensive draft document produced by the Haughton Institute under contract to the RPII and was finalised following extensive consultations with the relevant stakeholders. The revised Code includes a brief review of the current legislative framework and its specific impact on the management of building projects (Chapters 1 and 2), a presentation of the main types of radiological (Chapter 3) and nuclear medicine (Chapter 4) facilities, a treatment of the technical aspects of shielding calculations (Chapter 5) and a discussion of the practical aspects of implementing shielding solutions in a building context (Chapter 6). The primary purpose of the Code is to assist in the design of diagnostic facilities to the highest radiation protection standards in order to ensure the safety of workers and members of the public and the delivery of a safe service to patients. Diagnostic radiology is a dynamic environment and the Code is intended to be used in consultation with the current literature, an experienced Radiation Protection Advisor and a multidisciplinary project team

  14. Bi-Abundance Ionisation Structure of the Wolf-Rayet Planetary Nebula PB 8

    Danehkar, A.

    2018-01-01

    The planetary nebula PB 8 around a [WN/WC]-hybrid central star is one of planetary nebulae with moderate abundance discrepancy factors (ADFs 2-3), which could be an indication of a tiny fraction of metal-rich inclusions embedded in the nebula (bi-abundance). In this work, we have constructed photoionisation models to reproduce the optical and infrared observations of the planetary nebula PB 8 using a non-LTE stellar model atmosphere ionising source. A chemically homogeneous model initially used cannot predict the optical recombination lines. However, a bi-abundance model provides a better fit to most of the observed optical recombination lines from N and O ions. The metal-rich inclusions in the bi-abundance model occupy 5.6% of the total volume of the nebula, and are roughly 1.7 times cooler and denser than the mean values of the surrounding nebula. The N/H and O/H abundance ratios in the metal-rich inclusions are 1.0 and 1.7 dex larger than the diffuse warm nebula, respectively. To reproduce the Spitzer spectral energy distribution of PB 8, dust grains with a dust-to-gas ratio of 0.01 (by mass) were also included. It is found that the presence of metal-rich inclusions can explain the heavy element optical recombination lines, while a dual-dust chemistry with different grain species and discrete grain sizes likely produces the infrared continuum of this planetary nebula. This study demonstrates that the bi-abundance hypothesis, which was examined in a few planetary nebulae with large abundance discrepancies (ADFs > 10), could also be applied to those typical planetary nebulae with moderate abundance discrepancies.

  15. A new scheme for solving inhomogeneous Boltzmann equation for electrons in weakly ionised gases

    Mahmoud, M.O.M.; Yousfi, M.

    1995-01-01

    In the case of weakly ionized gases, the numerical treatment of non-hydrodynamic regime involving spatial variation of distribution function due to boundaries (walls, electrodes, electron source, etc hor-ellipsis) by using direct Boltzmann equation always constitute a challenge if the main collisional processes occurring in non thermal plasmas are to be considered (elastic, inelastic and super-elastic collisions, Penning ionisation, Coulomb interactions, etc hor-ellipsis). In the non-thermal discharge modelling, the inhomogeneous electron Boltzmann equation is needed in order to be coupled for example to a fluid model to take into account the electron non-hydrodynamic effects. This is for example the case of filamentary discharge, in which the space charge electric field due to streamer propagation has a very sharp spatial profile thus leading to important space non-hydrodynamic effects. It is also the case of the cathodic zone of glow discharge where electric field has a rapid spatial decrease until the negative glow. In the present work, a new numerical scheme is proposed to solve the inhomogeneous Boltzmann equation for electrons in the framework of two-term approximation (TTA) taking into account elastic and inelastic processes. Such a method has the usual drawbacks associated with the TTA i.e. not an accurate enough at high E/N values or in presence of high inelastic processes. But the accuracy of this method is considered sufficient because in a next step it is destinated to be coupled to fluid model for charged particles and a chemical kinetic model where the accuracy is of the same order of magnitude or worse. However there are numerous advantages of this method concerning time computing, treatment of non-linear collision processes (Coulomb, Penning, etc hor-ellipsis)

  16. Accurate simulation of ionisation chamber response with the Monte Carlo code PENELOPE

    Sempau, Josep; Andreo, Pedro

    2011-01-01

    Ionisation chambers (IC) are routinely used in hospitals for the dosimetry of the photon and electron beams used for radiotherapy treatments. The determination of absorbed dose to water from the absorbed dose to the air filling the cavity requires the introduction of stopping power ratios and perturbation factors, which account for the disturbance caused by the presence of the chamber. Although this may seem a problem readily amenable to Monte Carlo simulation, the fact is that the accurate determination of IC response has been, for various decades, one of the most important challenges of the simulation of electromagnetic showers. The main difficulty stems from the use of condensed history techniques for electron and positron transport. This approach, which involves grouping a large number of interactions into a single artificial event, is known to produce the so-called interface effects when particles travel across surfaces separating different media. These effects can be sizeable when the electron step length is not negligible compared to the size of the region being crossed, as it is the case with the cavity of an IC. The artefact, which becomes apparent when the chamber response shows a marked dependence on the adopted step size, can be palliated with the use of sophisticated electron transport algorithms. These topics are discussed in the context of the transport model implemented in the PENELOPE code. The degree of violation of the Fano theorem for a simple, planar geometry, is used as a measure of the stability of the algorithm with respect to variations of the electron step length, thus assessing the 'quality' of its condensed history scheme. It is shown that, with a suitable choice of transport parameters, PENELOPE simulates IC response with an accuracy of the order of 0.1%.

  17. Regulatory control and challenges in Medical facilities using ionising radiation sources

    Agarwal, S.P.

    2008-01-01

    Medical facilities utilising ionising radiation sources for diagnostic and treatment of cancer are regulated under the provisions of Atomic Energy (Radiation Protection) Rules, 2004 promulgated under the Atomic Energy Act 1962. The Competent Authority for the enforcement of the rules is Chairman, Atomic Energy Regulatory Board (AERB). Practice specific codes are issued by AERB for medical facilities such as Radiotherapy, Nuclear Medicine and Radiology. Regulatory process for control of medical facilities covers the entire life cycle of the radiation sources in three stages viz pre-Iicensing, during useful life and decommissioning and disposal. Pre-Iicensing requirements include use of type approved sources and equipment, approval of design layout of the facility and installation, exclusive (safe and secure) source storage facility when the equipment is not in use, radiation (area/individual) monitoring devices, qualified, trained and certified manpower, emergency response plans and commitment from the licensee for the safe disposal of disused/decayed sources. Compliance to these requirements makes the applicant eligible to obtain license from AERB for the operation of the medical facility. During the use of radiation sources, specific prior approval of the Competent Authority is required in respect of every source replacement, sale, transfer, transport, import and export. Further, all licensees are required to send the periodic safety Status reports to AERB as well as reporting of any off normal events. AERB conducts inspection of the facilities to ensure compliance with the safety requirements during operation of the facility. Violation of safety norms by licensee attracts enforcement action which includes suspension, modification or withdrawal of licensee for operation of the facility. Upon completion of the useful life of the source, the licensee decommissions the facility and returns the source to the original supplier. For returning the source, prior

  18. Recombination in liquid filled ionisation chambers with multiple charge carrier species: Theoretical and numerical results

    Aguiar, P.; González-Castaño, D.M.; Gómez, F.; Pardo-Montero, J.

    2014-01-01

    Liquid-filled ionisation chambers (LICs) are used in radiotherapy for dosimetry and quality assurance. Volume recombination can be quite important in LICs for moderate dose rates, causing non-linearities in the dose rate response of these detectors, and needs to be corrected for. This effect is usually described with Greening and Boag models for continuous and pulsed radiation respectively. Such models assume that the charge is carried by two different species, positive and negative ions, each of those species with a given mobility. However, LICs operating in non-ultrapure mode can contain different types of electronegative impurities with different mobilities, thus increasing the number of different charge carriers. If this is the case, Greening and Boag models can be no longer valid and need to be reformulated. In this work we present a theoretical and numerical study of volume recombination in parallel-plate LICs with multiple charge carrier species, extending Boag and Greening models. Results from a recent publication that reported three different mobilities in an isooctane-filled LIC have been used to study the effect of extra carrier species on recombination. We have found that in pulsed beams the inclusion of extra mobilities does not affect volume recombination much, a behaviour that was expected because Boag formula for charge collection efficiency does not depend on the mobilities of the charge carriers if the Debye relationship between mobilities and recombination constant holds. This is not the case in continuous radiation, where the presence of extra charge carrier species significantly affects the amount of volume recombination. - Highlights: • Analytical extension of Greening and Boag theories to multiple charge carriers. • Detailed numerical study of process of volume recombination in LICs. • Recombination in pulsed beams is independent of number and mobilities of carriers. • Multiple charge carriers have a significant effect in continuous

  19. Application of Radiation for the Control of Salmonellae in Various Foods; Destruction des Salmonellae par les Rayonnements dans Divers Produits Alimentaires; Primenenie izluchenij dlya unichtozheniya salmonell v razlichnykh pishchevykh produktakh; Empleo de las Radiaciones Ionizantes en la Lucha Contra las Salmonellae de Diferentes Aumentos

    Ley, F. J. [Wantage Research Laboratory (A.E.R.E.), Wantage, Berks. (United Kingdom)

    1966-11-15

    Microbiological studies on the use of ionizing radiation for the elimination of Salmonellae from various foods have demonstrated that a wide variety of factors can influence the radiation sensitivity of the organisms. These factors include the nature of the food itself and the temperature during irradiation, e.g. whether frozen or unfrozen. The difference in resistance of different serotypes of Salmonellae irradiated under the same conditions has also been well established. Dose/survival curves constructed for the purpose of making a choice of dose for a particular application must therefore be established for the practical conditions envisaged and be based on the most resistant serotype present. Since these conditions can never be exactly reproduced in the laboratory, the choice of dose should be confirmed by a substantial amount of work with the naturally-contaminated material. It is apparent that the doses required for the treatment of various foods lie within the' range 0.5 to 1.0 Mrad, achieving a reduction in numbers of initial populations by a factor of between 10{sup 5} and 10{sup 7} . The most promising processes are those considered for frozen and dried-egg products, frozen meats and animal feedingstuffs. (author) [French] A la suite d'etudes microbiologiques sur la possibilite d'employer des rayonnements ionisants pour detruire les Salmonellaedans divers produits alimentaires, il est apparu que la radio- sensibiliteide ces organismes depend de nombreux facteurs, en particulier de la nature du produit et de sa temperature (produit congele ou non) pendant l'irradiation. On a egalement reconnu que diverses varietes serologiques de Salmonellae, irradiees dans les memes conditions, ont une radioresistance differente. Des,courbes de survie en fonction de la dose, construites en vue de determiner la dose necessaire poiir Un traitement' donne, doivent donc etre etablies pour les conditions pratiques envisagees et compte tenu de la plus resistante des varietes

  20. The electrical charging of inactive aerosols in high ionised atmosphere, the electrical charging of artificial beta radioactive aerosols; Le processus de charge electrique: des aerosols non radioactifs en milieu fortement ionise, des aerosols radioactifs artificiels emetteurs beta

    Gensdarmes, F

    2000-07-01

    The electrical properties of aerosols greatly influence their transport and deposition in a containment. In a bipolar ionic atmosphere, a neutral electric charge on aerosols is commonly assumed. However, many studies report a different charge distribution in some situations, like highly ionised atmosphere or in the case of radioactive aerosols. Such situations could arise from a hypothetical accident in a nuclear power plant. Within the framework of safety studies which are carried out at IPSN, our aims were the study of electrical properties of aerosols in highly ionised atmosphere, and the study of artificial radioactive aerosols, in order to suggest experimental validation of available theories. For this purpose, we designed an experimental device that allows us to measure non-radioactive aerosol charge distribution under high gamma irradiation, up to 10{sup 4} Gy/h. With our experimental device we also studied the properties of small ions in the medium. Our results show a variation of the charge distribution in highly ionised atmosphere. The charge increases with the dose of gamma ray. We have related this variation with the one of the small ions in the gases, according to theoretical prediction. However, the model overestimates slightly our experimental results. In the case of the radioactive aerosols, we have designed an original experimental device, which allows us to study the charge distribution of a {sup 137}Cs aerosol. Our results show that the electric charging of such aerosols is strongly dependent on evolution parameters in a containment. So, our results underline a great enhancement of self-charging of particles which are sampled in a confined medium. Our results are qualitatively in agreement with the theoretical model; nevertheless the latter underestimates appreciably the self-charging, owing to the fact that wall effects are not taken into account. (author)

  1. Contribution to the study of the action of electromagnetic fields on the angular correlations of nuclear radiation (1960); Contribution a l'etude de l'action des champs electromagnetiques sur les correlations angulaires des rayonnements nucleaires (1960)

    Lehmann, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1959-01-15

    This work deals with the study of interaction of E.M. fields with nuclear moments of nuclei emitting gamma rays. We describe first experiments on delayed angular correlation showing the role played by statistic quadrupole interaction. We have measured the magnetic moment of the second excited state of {sup 19}F using an external magnetic field. In the case of {sup 19}O, experiments of angular distributions and angular correlations of gamma -rays taking into account the possibility of perturbations, allow us to determine the spin and parities of the three first levels. (author) [French] Le present travail concerne l'etude de l'interaction des champs electromagnetiques et des moments nucleaires de noyaux emettant des rayonnements gamma. Nous decrivons des experiences de correlation angulaire differee dont l'interpretation met en coincidence le role joue par les interactions quadrupolaires statiques. Nous avons mesure le moment magnetique de {sup 19}F dans un etat excite en utilisant un champ magnetique exterieur a la source radioactive. Enfin, dans le cas de {sup 19}O, nous montrons l'utilite d'un examen des possibilites de perturbations dans l'interpretation des resultats fournis par des correlations ou des distributions angulaires. (auteur)

  2. Contribution to the study of the action of electromagnetic fields on the angular correlations of nuclear radiation (1960); Contribution a l'etude de l'action des champs electromagnetiques sur les correlations angulaires des rayonnements nucleaires (1960)

    Lehmann, P. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1959-01-15

    This work deals with the study of interaction of E.M. fields with nuclear moments of nuclei emitting gamma rays. We describe first experiments on delayed angular correlation showing the role played by statistic quadrupole interaction. We have measured the magnetic moment of the second excited state of {sup 19}F using an external magnetic field. In the case of {sup 19}O, experiments of angular distributions and angular correlations of gamma -rays taking into account the possibility of perturbations, allow us to determine the spin and parities of the three first levels. (author) [French] Le present travail concerne l'etude de l'interaction des champs electromagnetiques et des moments nucleaires de noyaux emettant des rayonnements gamma. Nous decrivons des experiences de correlation angulaire differee dont l'interpretation met en coincidence le role joue par les interactions quadrupolaires statiques. Nous avons mesure le moment magnetique de {sup 19}F dans un etat excite en utilisant un champ magnetique exterieur a la source radioactive. Enfin, dans le cas de {sup 19}O, nous montrons l'utilite d'un examen des possibilites de perturbations dans l'interpretation des resultats fournis par des correlations ou des distributions angulaires. (auteur)

  3. Measurement of air kerma rates for 6- to 7-MeV high-energy gamma-ray field by ionisation chamber and build-up plate.

    Kowatari, Munehiko; Tanimura, Yoshihiko; Tsutsumi, Masahiro

    2014-12-01

    The 6- to 7-MeV high-energy gamma-ray calibration field by the (19)F(p, αγ)(16)O reaction is to be served at the Japan Atomic Energy Agency. For the determination of air kerma rates using an ionisation chamber in the 6- to 7-MeV high-energy gamma-ray field, the establishment of the charged particle equilibrium must be achieved during measurement. In addition to measurement of air kerma rates by the ionisation chamber with a thick build-up cap, measurement using the ionisation chamber and a build-up plate (BUP) was attempted, in order to directly determine air kerma rates under the condition of regular calibration for ordinary survey meters and personal dosemeters. Before measurements, Monte Carlo calculations were made to find the optimum arrangement of BUP in front of the ionisation chamber so that the charged particle equilibrium could be well established. Measured results imply that air kerma rates for the 6- to 7-MeV high-energy gamma-ray field could be directly determined under the appropriate condition using an ionisation chamber coupled with build-up materials. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  4. The ENEA calibration service for ionising radiations; Il centro di taratura per le radiazioni ionizzanti di Bologna. Parte 1: Fotoni

    Monteventi, F.; Sermenghi, I. [ENEA, Centro Ricerche Ezio Clementel, Bologna (Italy). Dipt. Ambiente

    1999-07-01

    The report describes all the facilities available at the the service of the ENEA Calibration Service for Ionising Radiations at Bologna (Italy). It gives a detailed description of all equipment qualified for photon fields metrology including the secondary standards and the calibration procedures performed for radiation monitoring devices and dosemeters. [Italian] Il presente lavoro descrive i servizi e le attivita' del Centro di Taratura dell'ENEA di Bologna, in particolare delle attrezzature qualificate per la metrologia fotonica, dei campioni di misura e delle procedure adottate per la taratura degli strumenti e dei dosimetri.

  5. IBM-PC based data acquisition system for a laser enhanced ionisation spectrometer using a low cost GPIB card

    Sampath Kumar, R.; Ravindranath, S.V.G.

    1992-01-01

    An IBM-PC based data acquisition system has been developed for the existing laser enhanced ionisation spectrometer in the Division. Here the boxcar averager (type SR 250) which integrates the spectrometer output is interfaced to an IBM-PC, converted into a GPIB controller with the help of a locally available GPIB card, (Dynalog Micro Systems make PCL 848) through the GPIB port of the computer interface module (SR 245). The menu driven software developed in BASIC, triggers the scan in the dye laser through its control port, collects data from the spectrometer, plots, displays and stores it on the hard disc for further use. (author). 6 refs., 18 figs., 2 appendixes

  6. Current status of matrix-assisted laser desorption ionisation-time of flight mass spectrometry in the clinical microbiology laboratory.

    Kok, Jen; Chen, Sharon C A; Dwyer, Dominic E; Iredell, Jonathan R

    2013-01-01

    The integration of matrix-assisted laser desorption ionisation-time of flight mass spectrometry (MALDI-TOF MS) into many clinical microbiology laboratories has revolutionised routine pathogen identification. MALDI-TOF MS complements and has good potential to replace existing phenotypic identification methods. Results are available in a more clinically relevant timeframe, particularly in bacteraemic septic shock. Novel applications include strain typing and the detection of antimicrobial resistance, but these are not widely used. This review discusses the technical aspects, current applications, and limitations of MALDI-TOF MS.

  7. Predicting the effects of ionising radiation on ecosystems by a generic model based on the Lotka-Volterra equations

    Monte, Luigi

    2009-01-01

    The present work describes a model for predicting the population dynamics of the main components (resources and consumers) of terrestrial ecosystems exposed to ionising radiation. The ecosystem is modelled by the Lotka-Volterra equations with consumer competition. Linear dose-response relationships without threshold are assumed to relate the values of the model parameters to the dose rates. The model accounts for the migration of consumers from areas characterised by different levels of radionuclide contamination. The criteria to select the model parameter values are motivated by accounting for the results of the empirical studies of past decades. Examples of predictions for long-term chronic exposure are reported and discussed.

  8. The report of the French Academy of Science: 'Problems associated with the effects of low doses of ionising radiation'

    Tubiana, M.

    1998-01-01

    In 1995 the French Academy of Science published a report on 'Problems associated with low doses of ionising radiation'. This report aroused interest among French-speaking scientists and a translation in English was published a year later. The report pointed out that an important issue in radioprotection was not whether to accept or reject the linear no-threshold model but rather to test its validity. The aim of this review is to analyse the report and its recommendations, and to briefly indicate the progress which has been made and the questions which remain open. Three areas of the report are covered in this review: DNA repair, carcinogenesis and epidemiological data. (author)

  9. Use of the Isomass 54E thermal ionisation mass spectrometer at AEE Winfrith. Part II: plutonium analysis

    Knight, A.P.

    1982-06-01

    This report describes the application of the Isomass 54E Thermal ionisation mass spectrometer for the isotopic analysis of plutonium, and gives details of the development of a method for quantitative determination of plutonium in sample solutions using isotopic dilution. A computer program for the control of the 54E is also described. Isotope dilution was used to compare results of plutonium content of twelve zebra reactor fuel pellets with results obtained by titrimetry. The Isomass 54E is shown to be capable of high precision analysis of plutonium sample solutions for both isotopic content and total plutonium concentration using an isotope dilution technique. (U.K.)

  10. Saturation effects in the ionisation of He by H/sup +/ and He/sup 2+/ impact at intermediate energies

    Bernardi, G.C.; Garibotti, C.R.; Suarez, S.; Fainstein, P.D.

    1989-01-01

    Projectile charge dependence of double differential ionisation cross section for H/sup +/ and He/sub 3//sup 2+/ on He is studied both theoretically and experimentally. The experimental ratio R of the emission induced by 50 and 100 KeV/u He/sub 3//sup 2+/ and H/sup +/ is compared with calculations from the CDW-EIS model. We report two main effects: (a) a decrease of R with increasing angle of electronic emission, (b) a sudden enhancement of R in the high energy side of the ECC peak.

  11. The solar ionisation rate deduced from Ulysses measurements and its implications to interplanetary Lyman alpha-intensity

    Summanen, T.; Kyroelae, E.

    1995-01-01

    We have developed a computer code which can be used to study 3-dimensional and time-dependent effects of the solar cycle on the interplanetary (IP) hydrogen distribution. The code is based on the inverted Monte Carlo simulation. In this work we have modelled the temporal behaviour of the solar ionisation rate. We have assumed that during the most of the time of the solar cycle there is an anisotopic latitudinal structure but right at the solar maximum the anisotropy disappears. The effects of this behaviour will be discussed both in regard to the IP hydrogen distribution and IP Lyman a a-intensity.

  12. Double spike methodology for uranium determination by thermal ionisation mass spectrometry: separation and purification of 234U

    Shah, P.M.; Saxena, M.K.; Sanjai Kumar; Aggarwal, S.K.; Jain, H.C.

    1995-01-01

    With an objective to prepare double spike of 233 U+ 234 U for determination of uranium concentration by Isotopic Dilution Thermal Ionisation Mass Spectrometry (ID-TIMS), 234 U was separated and purified from aged 238 Pu sample (15 years old) using several ion exchange and solvent extraction procedures. Final product containing 95% and 5% alpha activities of 234 and 238 Pu, respectively, which translates into 99.998 atom% of 234 U and 0.002 atom% of 238 Pu was found suitable for double spike. (author). 1 ref

  13. Proposal for a Graded Authorisation Model for the Use of Ionising Radiation in Ireland

    NONE

    2012-10-15

    The Radiological Protection Institute of Ireland RPII intends to refocus, streamline and modernise its regulation of the use of ionising radiation in Ireland. This report provides detailed proposals for establishing a graded approach to authorisation in which regulators will be able to focus on higher risk practices by simplifying requirements placed on those of lower risk, without compromising the safety or security of the Irish population. These proposals build on RPII strategic analyses that seek to navigate a course between the competing pressures of public sector reform and the rapid technological changes in medical and nuclear arenas, which challenge the licensing and advisory functions of RPII. A graded approach to authorisation provides the potential for a sustainable basis for future regulation in Ireland. Such an approach would be in line with the forthcoming EURATOM Basic Safety Standards and with general current regulatory trends, which are moving away from one-size-fits-all approaches towards more adaptive, interactive and transparent regulation. In seeking this reform, the RPII also aims to fully utilize the benefits of the internet and electronic communications and to improve the transparency of its processes. These proposals have been developed using a robust, comprehensive project methodology involving a root and branch analysis of current and potential future approaches to authorisation. A series of facilitated workshops were held, punctuated by intensive periods of focused co-enquiry, involving all members of the RPII Regulatory Service. This approach made the fullest use of the decades of expertise and knowledge of these staff. It also provided the platform for developing a common vision of a graded approach to authorisation; for agreeing the criteria for differentiating between levels of authorisation; for collecting the necessary evidence for decision-making and for identifying the implications of these decisions. The graded approach presented

  14. Proposal for a Graded Authorisation Model for the Use of Ionising Radiation in Ireland

    2012-10-01

    The Radiological Protection Institute of Ireland RPII intends to refocus, streamline and modernise its regulation of the use of ionising radiation in Ireland. This report provides detailed proposals for establishing a graded approach to authorisation in which regulators will be able to focus on higher risk practices by simplifying requirements placed on those of lower risk, without compromising the safety or security of the Irish population. These proposals build on RPII strategic analyses that seek to navigate a course between the competing pressures of public sector reform and the rapid technological changes in medical and nuclear arenas, which challenge the licensing and advisory functions of RPII. A graded approach to authorisation provides the potential for a sustainable basis for future regulation in Ireland. Such an approach would be in line with the forthcoming EURATOM Basic Safety Standards and with general current regulatory trends, which are moving away from one-size-fits-all approaches towards more adaptive, interactive and transparent regulation. In seeking this reform, the RPII also aims to fully utilize the benefits of the internet and electronic communications and to improve the transparency of its processes. These proposals have been developed using a robust, comprehensive project methodology involving a root and branch analysis of current and potential future approaches to authorisation. A series of facilitated workshops were held, punctuated by intensive periods of focused co-enquiry, involving all members of the RPII Regulatory Service. This approach made the fullest use of the decades of expertise and knowledge of these staff. It also provided the platform for developing a common vision of a graded approach to authorisation; for agreeing the criteria for differentiating between levels of authorisation; for collecting the necessary evidence for decision-making and for identifying the implications of these decisions. The graded approach presented

  15. Investigation of cellular signalling responses to non-ionising radiation in melanocytes by microarray analysis

    Boyle, G.M.; Pedley, J.; Martyn, A.C.; Fraser, L.M.; Banducci, K.J.; Parsons, P.G.; Breit, S.N.

    2003-01-01

    Melanoma is a highly aggressive cancer resulting from the abnormal proliferation and spread of specialised pigment cells in the skin, known as melanocytes. Extensive epidemiological and molecular evidence suggests that a major risk factor for melanoma formation is exposure to non-ionising radiation in the form of solar ultra-violet (UV) light. However, the exact role of solar UV in the development of melanoma is unclear. To elucidate the molecular events that occur in melanocytes following solar UV exposure and determine how they lead to melanoma development, cDNA microarray analysis was used to analyse the gene expression profile of normal melanocytes, melanocytes exposed to simulated solar UV and melanoma cells. The development of cDNA microarray technology has allowed gene expression profiling at the mRNA level to be conducted for many thousands of genes simultaneously by hybridising an array of known sequences with labelled cDNA reverse transcribed form the sample RNA. Gene expression analysis was performed for over 13,000 genes. More than 500 genes were identified as differentially expressed in melanocytes following a single UV exposure, although overall there was a general suppression of transcription. Genes that were up-regulated included oncogenes and cytoskeletal genes; in contrast, genes encoding protein tyrosine kinases and apoptosis effectors were down-regulated. Many of the genes identified as being differentially expressed represent novel UV-regulated targets. Repeated exposure to solar UV resulted in the elevation in expression of a novel member of the transforming growth factor-b (TGF-b) superfamily, the Macrophage Inhibitory Cytokine-1 (MIC-1). Our results have shown that MIC-1 is up-regulated by solar UV in melanocytes, and is highly expressed (>3 fold) in a number of metastatic melanoma cell lines (31/61) in comparison to primary melanocytes. Furthermore functional, dimerised MIC-1 was found to be secreted by melanocytes, and secreted levels were

  16. The multiple stressor effect in zebrafish embryos from simultaneous exposure to ionising radiation and cadmium

    Ng, C Y P; Choi, V W Y; Lam, A C L; Yu, K N; Cheng, S H

    2013-01-01

    Living organisms are exposed to a mixture of environmental stressors, and the resultant effects are referred to as multiple stressor effects. In the present work, we studied the multiple stressor effect in embryos of the zebrafish (Danio rerio) from simultaneous exposure to ionising radiation (alpha particles) and cadmium through quantification of apoptotic signals at 24 h postfertilisation (hpf) revealed by vital dye acridine orange staining. For each set of experiments, 32–40 dechorionated embryos were deployed, which were divided into four groups each having 8–10 embryos. The four groups of embryos were referred to as (1) the control group (C), which received no further treatments after dechorionation; (2) the Cd-dosed and irradiated group (CdIr), which was exposed to 100 μM Cd from 5 to 24 hpf, and also received about 4.4 mGy from alpha particles at 5 hpf; (3) the irradiated group (Ir), which received about 4.4 mGy from alpha particles at 5 hpf; and (4) the Cd-dosed group (Cd), which was exposed to 100 μM Cd from 5 to 24 hpf. In general, the CdIr, Ir and Cd groups had more apoptotic signals than the C group. Within the 12 sets of experimental results, two showed significant synergistic effects, one showed a weakly synergistic effect and nine showed additive effects. The multiple stressor effect of 100 μM Cd with ∼4.4 mGy alpha-particle radiation resulted in an additive or synergistic effect, but no antagonistic effect. The failure to identify significant synergistic effects for some sets of data, and thus their subsequent classification as additive effects, might be a result of the relatively small magnitude of the synergistic effects. The results showed that the radiation risk could be perturbed by another environmental stressor such as a heavy metal, and as such a realistic human radiation risk assessment should in general take into account the multiple stressor effects. (paper)

  17. Derivation of hazardous doses for amphibians acutely exposed to ionising radiation

    Fuma, Shoichi; Watanabe, Yoshito; Kawaguchi, Isao; Takata, Toshitaro; Kubota, Yoshihisa; Ban-nai, Tadaaki; Yoshida, Satoshi

    2012-01-01

    Derivation of effect benchmark values for each taxonomic group, which has been difficult due to lack of experimental effects data, is required for more adequate protection of the environment from ionising radiation. Estimation of effects doses from nuclear DNA mass and subsequent species sensitivity distribution (SSD) analysis were proposed as a method for such a derivation in acute irradiation situations for assumed nuclear accident scenarios. As a case study, 5% hazardous doses (HD 5 s), at which only 5% of species are acutely affected at 50% or higher lethality, were estimated on a global scale. After nuclear DNA mass data were obtained from a database, 50% lethal doses (LD 50 s) for 4.8 and 36% of the global Anura and Caudata species, respectively, were estimated by correlative equations between nuclear DNA mass and LD 50 s. Differences between estimated and experimental LD 50 s were within a factor of three. The HD 5 s obtained by the SSD analysis of these estimated LD 50 s data were 5.0 and 3.1 Gy for Anura and Caudata, respectively. This approach was also applied to the derivation of regional HD 5 s. The respective HD 5 s were 6.5 and 3.2 Gy for Anura and Caudata inhabiting Japan. This HD 5 value for the Japanese Anura was significantly higher than the global value, while Caudata had no significant difference in global and Japanese HD 5 s. These results suggest that this approach is also useful for derivation of regional benchmark values, some of which are likely different from the global values. - Highlights: ► A possible method was proposed for derivation of an effect benchmark value for each taxonomic group. ► 50% lethal doses were estimated from nuclear DNA mass in amphibian species. ► 5% hazardous doses (HD 5 s) were estimated by species sensitivity distribution. ► Respective HD 5 s were 5.0 and 3.1 Gy for Anura and Caudata globally. ► Respective HD 5 s were 6.5 and 3.2 Gy for Anura and Caudata inhabiting Japan.

  18. WE-G-BRA-06: Calibrating an Ionisation Chamber: Gaining Experience Using a Dosimetry 'flight Simulator'.

    Beavis, A; Saunderson, J; Ward, J

    2012-06-01

    Recently there has been great interest in the use of simulation training, with the view to enhance safety within radiotherapy practice. We have developed a Virtual Environment for Radiotherapy Training (VERT) which facilitates this, including the simulation of a number of 'Physics practices'. One such process is the calibration of an ionisation chamber for use in Linac photon beams. The VERT system was used to provide a life sized 3D virtual environment within which we were able to simulate the calibration of a departmental chamber for 6MV and 15 MV beams following the UK 1990 Code of Practice. The characteristics of the beams are fixed parameters in the simulation, whereas default (Absorbed dose to water) correction factors of the chambers are configurable thereby dictating their response in the virtual x-ray beam. When the simulation is started, a random, realistic temperature and pressure is assigned to the bunker. Measurement and chamber positional errors are assigned to the chambers. A virtual water phantom was placed on the Linac couch and irradiated through the side using a 10 × 10 field. With a chamber at the appropriate depths and irradiated iso-centrically, the Quality Indices (QI) of the beams were obtained. The two chambers were 'inter-compared', allowing the departmental chamber calibration factor to be calculated from that of the reference chamber. For the virtual 6/15 MV beams, the QI were found to be 0.668/ 0.761 and the inter-comparison ratios 0.4408/ 0.4402 respectively. The departmental chamber calibration factors were calculated; applying these and appropriate environmental corrections allowed the output of the Linac to be confirmed. We have shown how a virtual training environment can be used to demonstrate practical processes and reinforce learning. The UK CoP was used here, however any relevant protocol could be demonstrated. Two of the authors (Beavis and Ward) are Founders of Vertual Ltd, a spin-out company created to commercialise the

  19. A preliminary inter-centre comparison study for photon, thermal neutron and epithermal neutron responses of two pairs of ionisation chambers used for BNCT

    Roca, Antoaneta; Liu, Yuan-Hao; Wojnecki, Cecile; Green, Stuart; Nievaart, Sander; Ghani, Zamir; Moss, Ray

    2009-01-01

    The dual ionisation chamber technique is the recommended method for mixed field dosimetry of epithermal neutron beams. This paper presents initial data from an ongoing inter-comparison study involving two identical pairs of ionisation chambers used at the BNCT facilities of Petten, NL and of University of Birmingham, UK. The goal of this study is to evaluate the photon, thermal neutron and epithermal neutron responses of both pairs of TE(TE) (Exradin T2 type) and Mg(Ar) (Exradin M2 type) ionisation chambers in similar experimental conditions. At this stage, the work has been completed for the M2 type chambers and is intended to be completed for the T2 type chambers in the near future.

  20. Internet-based ICRP resource for healthcare providers on the risks and benefits of medical imaging that uses ionising radiation.

    Demeter, S; Applegate, K E; Perez, M

    2016-06-01

    The purpose of the International Commission on Radiological Protection (ICRP) Committee 3 Working Party was to update the 2001 web-based module 'Radiation and your patient: a guide for medical practitioners' from ICRP. The key elements of this task were: to clearly identify the target audience (such as healthcare providers with an emphasis on primary care); to review other reputable sources of information; and to succinctly publish the contribution made by ICRP to the various topics. A 'question-and-answer' format addressing practical topics was adopted. These topics included benefits and risks of imaging using ionising radiation in common medical situations, as well as pertaining to specific populations such as pregnant, breast-feeding, and paediatric patients. In general, the benefits of medical imaging and related procedures far outweigh the potential risks associated with ionising radiation exposure. However, it is still important to ensure that the examinations are clinically justified, that the procedure is optimised to deliver the lowest dose commensurate with the medical purpose, and that consideration is given to diagnostic reference levels for particular classes of examinations. © The International Society for Prosthetics and Orthotics.

  1. An enhanced ionising radiation monitoring and detecting technique in radiotherapy units of hospitals using wireless sensor networks

    Ali, Peter

    2017-01-01

    In this paper, a solution of ionising radiation monitoring based on the concept of Wireless Sensor Network (WSN), is presented. Radiation dose rate measured by the sensor node is sent to the monitoring station through ZigBee wireless network operated on 2.4 GHz unlicensed Industrial Scientific Medical (ISM) band. The system is calibrated for use for ionizing radiation dose rate range of between amount of ionising radiation observed in radiotherapy unit of a hospital and 1.02 mSv/h. Power consumption of the sensor node is kept low by operating the node ZigBee radio with low duty cycle: i.e. by keeping the radio awake only during data transmission/reception. Two ATmega8 microcontrollers, one each for sensor node and the monitoring station, are programmed to perform interfacing, data processing, and control functions. The system range of coverage is 124m for outdoor (line of site) deployment and 56.8m for indoor application where 5 brick walls separated the sensor node and the monitoring station. Range of coverage of the system is extendable via the use of ZigBee router (s)

  2. Assessing the surroundings for effects of ionising radiation on the granting of permits, DOVIS A. Emissions to air and water

    Blaauboer, R O

    2002-01-01

    In the Netherlands, as in most other countries, one generally needs a permit to produce (including the manufacture, processing, control and storage), to apply or to dispose of radioactive materials, or to use equipment that produces ionising radiation. This permit must be in accordance with the Nuclear Energy Act. Limits that are set for radioactive material can be found in the Decree on radiation protection ('Besluit stralings-bescherming') which has been in force since March 1, 2002. Along with the application for a permit, calculation results have to be submitted on the radiation dose that members of the public receive as a consequence of (possible) emissions of radioactive material (into the atmosphere or surface water) or as a consequence of external irradiation. Fairly rough estimates, based on simple rules, will often be satisfactory. These rules can be found in an annex of a Ministerial Order on the assessment of consequences of ionising radiation (mr-AGIS). However, in some cases this will not be ade...

  3. Characterisation of ionisation chambers for a mixed radiation field and investigation of their suitability as radiation monitors for the LHC.

    Theis, C; Forkel-Wirth, D; Perrin, D; Roesler, S; Vincke, H

    2005-01-01

    Monitoring of the radiation environment is one of the key tasks in operating a high-energy accelerator such as the Large Hadron Collider (LHC). The radiation fields consist of neutrons, charged hadrons as well as photons and electrons with energy spectra extending from those of thermal neutrons up to several hundreds of GeV. The requirements for measuring the dose equivalent in such a field are different from standard uses and it is thus necessary to investigate the response of monitoring devices thoroughly before the implementation of a monitoring system can be conducted. For the LHC, it is currently foreseen to install argon- and hydrogen-filled high-pressure ionisation chambers as radiation monitors of mixed fields. So far their response to these fields was poorly understood and, therefore, further investigation was necessary to prove that they can serve their function well enough. In this study, ionisation chambers of type IG5 (Centronic Ltd) were characterised by simulating their response functions by means of detailed FLUKA calculations as well as by calibration measurements for photons and neutrons at fixed energies. The latter results were used to obtain a better understanding and validation of the FLUKA simulations. Tests were also conducted at the CERF facility at CERN in order to compare the results with simulations of the response in a mixed radiation field. It is demonstrated that these detectors can be characterised sufficiently enough to serve their function as radiation monitors for the LHC.

  4. Airborne hydrogen cyanide measurements using a chemical ionisation mass spectrometer for the plume identification of biomass burning forest fires

    M. Le Breton

    2013-09-01

    Full Text Available A chemical ionisation mass spectrometer (CIMS was developed for measuring hydrogen cyanide (HCN from biomass burning events in Canada using I− reagent ions on board the FAAM BAe-146 research aircraft during the BORTAS campaign in 2011. The ionisation scheme enabled highly sensitive measurements at 1 Hz frequency through biomass burning plumes in the troposphere. A strong correlation between the HCN, carbon monoxide (CO and acetonitrile (CH3CN was observed, indicating the potential of HCN as a biomass burning (BB marker. A plume was defined as being 6 standard deviations above background for the flights. This method was compared with a number of alternative plume-defining techniques employing CO and CH3CN measurements. The 6-sigma technique produced the highest R2 values for correlations with CO. A normalised excess mixing ratio (NEMR of 3.68 ± 0.149 pptv ppbv−1 was calculated, which is within the range quoted in previous research (Hornbrook et al., 2011. The global tropospheric model STOCHEM-CRI incorporated both the observed ratio and extreme ratios derived from other studies to generate global emission totals of HCN via biomass burning. Using the ratio derived from this work, the emission total for HCN from BB was 0.92 Tg (N yr−1.

  5. Radio-oxidation of an EPDM elastomer under weak or strong ionising radiations: measurement and modelling of dioxygen consumption

    Dely, N.

    2005-10-01

    Usually, the irradiation of polymers under ionising radiations occurs in air that is in the presence of oxygen. This leads to a radio oxidation process and to oxygen consumption. Our material is an EPDM elastomer (ethylene propylene 1,4 hexadiene) used as insulator in control-command cables in nuclear plants (Pressurised Water Reactor). A specific device has been conceived and built up during this PhD work for measuring very small oxygen consumptions with an accuracy of around 10%. Ionising radiations used are electrons at 1 MeV and carbon ions at 11 MeV per nucleon. Under both electron and ion irradiations, the influence of oxygen pressure on oxygen consumption has been studied in a very large range: between 1 and 200 mbar. In both cases, the yield of oxygen consumption is constant in-between 200 and 5 mbar. Then, at lower pressures, it decreases appreciably. On the other hand, the oxygen consumption during ion irradiation is four times smaller than during electron irradiation. This emphasizes the role of the heterogeneity of the energy deposition at a nano-metric scale. The adjustment of the experimental results obtained during electron irradiation with the general homogeneous steady-state kinetic model has allowed extracting all the values of the kinetic parameters for the chosen mechanism of radio oxidation. The knowledge of these numbers will allow us to face our results obtained during ion irradiation with a heterogeneous kinetic model under development. (author)

  6. Ionised gas structure of 100 kpc in an over-dense region of the galaxy group COSMOS-Gr30 at z 0.7

    Epinat, B.; Contini, T.; Finley, H.; Boogaard, L. A.; Guérou, A.; Brinchmann, J.; Carton, D.; Michel-Dansac, L.; Bacon, R.; Cantalupo, S.; Carollo, M.; Hamer, S.; Kollatschny, W.; Krajnović, D.; Marino, R. A.; Richard, J.; Soucail, G.; Weilbacher, P. M.; Wisotzki, L.

    2018-01-01

    We report the discovery of a 104 kpc2 gaseous structure detected in [O II]λλ3727, 3729 in an over-dense region of the COSMOS-Gr30 galaxy group at z 0.725 with deep MUSE Guaranteed Time Observations. We estimate the total amount of diffuse ionised gas to be of the order of ( 5 ± 3) × 1010 M⊙ and explore its physical properties to understand its origin and the source(s) of the ionisation. The MUSE data allow the identification of a dozen group members that are embedded in this structure through emission and absorption lines. We extracted spectra from small apertures defined for both the diffuse ionised gas and the galaxies. We investigated the kinematics and ionisation properties of the various galaxies and extended gas regions through line diagnostics (R23, O32, and [O III]/Hβ) that are available within the MUSE wavelength range. We compared these diagnostics to photo-ionisation models and shock models. The structure is divided into two kinematically distinct sub-structures. The most extended sub-structure of ionised gas is likely rotating around a massive galaxy and displays filamentary patterns that link some galaxies. The second sub-structure links another massive galaxy that hosts an active galactic nucleus (AGN) to a low-mass galaxy, but it also extends orthogonally to the AGN host disc over 35 kpc. This extent is likely ionised by the AGN itself. The location of small diffuse regions in the R23 vs. O32 diagram is compatible with photo-ionisation. However, the location of three of these regions in this diagram (low O32, high R23) can also be explained by shocks, which is supported by their high velocity dispersions. One edge-on galaxy shares the same properties and may be a source of shocks. Regardless of the hypothesis, the extended gas seems to be non-primordial. We favour a scenario where the gas has been extracted from galaxies by tidal forces and AGN triggered by interactions between at least the two sub-structures. Based on observations made with

  7. Germany (Federal Republic). Ministry of the Interior. Order on protection against damage due to ionising radiation. Radiation Protectin Order. StrlSchV 20 Oct. 1976

    1977-02-01

    The order is arranged in parts, entitled: introductory provisions; control provisions (handling radioactive matter, the carriage of radioactive matter, the import and export of radioactive matter, the construction and operation of installation for generating ionising radiation, employees and other persons working under supervision, design approval); safety regulations (general regulations, protection of the population and the environment against the hazards of ionising radiation, occupational exposure to radiation, radiation protection areas, physical protection and control, medical supervision, instruments for measuring radiation, other safety regulations); fines; and final provisions. (U.K.)

  8. Beta-Excited Sources of Electromagnetic Radiation; Sources de rayonnements electromagnetiques excites par des particules beta; Vozbuzhdennye beta-chastitsami istochniki ehlektromagnitnogo izlucheniya; Fuentes de radiacion electromagnetica excitadas por particulas beta

    Cameron, J F; Rhodes, J R [Physics Group, Isotope Research Division, (AERE), Wantage Research Laboratory, Wantage, Berks (United Kingdom)

    1962-01-15

    Beta-excited sources of electromagnetic radiation covering the energy region 1-200 keV and suitable for industrial use are described. H{sup 3}, Pm{sup 147}, Kr{sup 85}, Tl{sup 204} and (Sr+Y){sup 90} were chosen as sources of beta particles by the criteria of long half-life, low price, ready availability and high specific activity. The {beta}-excited sources have been designed on the basis of a compromise between practical source construction and the best theoretical efficiency in a given energy region. In their paper, the authors calculate the number of photons produced per beta particle and consider how the results must be corrected for self-absorption of the X-rays. In the calculations account is taken of both bremsstrahlung and characteristic {alpha}-radiation; optimum characteristic X-ray yield is achieved for targets with an atomic number between 40 and 60. ''Sandwich'' targets of 1-2 beta half-value thicknesses are found to give maximum photon-yields in the desired energy region. Al, Ag and Au are suitable from the manufacturing point of view as source coverings. They were also found to give satisfactory bremsstrahlung and X-ray yields and distribution for various energy regions in the range 1-200 keV when correctly combined with the above-mentioned D-emitters. Some energy spectra are given and absorption curves in Al and Fe are shown for the best source-target combinations. The difference between sources constructed of {beta}-emitters sandwiched between target foils and intimate source-target mixtures was found to be small. Tables are given as a guide to the best source to be used for a particular absorber thickness range. (author) [French] Les auteurs decrivent des sources de rayonnements electromagnetiques excites par des particules beta, couvrant une gamme d'energies allant de 1 a 200 keV et convenant aux usages industriels. Comme sources de particules beta on a choisi le tritium, le {sup 147}Pm, le {sup 85}Kr, le {sup 204}Tl et le {sup 90}(Sr+Y), en

  9. Radioisotopes and Radiation in Animal and Plant Insect Pest Control; Emploi des radioisotopes et des rayonnements dans la lutte contre les insectes nuisibles aux plantes et aux animaux; Ispol'zovanie radioizotopov i radiashchi v bor'be s nasekomymi-vreditelyami rastenij i zhivotnykh; Utilizacion de los radioisotopos y de las radiaciones en la lucha contra los insectos nocivos para las plantas y los animales

    Andreev, S. V.; Martens, B. K.; Samojlova, V. A.; Molchanova, Z. I. [Vsesoyuznyj Institut Zashchity Rastenij, Leningrad, SSSR (Russian Federation)

    1963-09-15

    rayonnements ionisants sur les micro-organismes entomopathogenes (Beauveria bassiana Unill.) a permis de demontrer la possibilite d'accroitre leur virulence et, partant, d'ameliorer la methode microbiologique de lutte contre les insectes nuisibles. L'action sterilisante et letale des rayonnements ionisants peut etre utilisee comme moyen actif de lutte contre ces insectes. On a determine les doses de sterilisation a l'aide des rayons gamma pour un certain nombre d'insectes ravageurs des recoltes stockees (Calandra granaria L., Acanthoscelides obtectus Say, Pectinophota malvella Hb, Leptinotarsa decemlineota Say, Chloridea obsoleta F.) et des semences. Les donnees obtenues a la suite des recherches permettront de mettre au point et de perfectionner les methodes de lutte contre les insectes nuisibles, notamment a l'agriculture. (author) [Spanish] El problema de la lucha contra los insectos daninos es de gran importancia para las economias nacionales. Los ultimos descubrimientos de la ciencia pueden contribuir considerablemente a resolverlo. A fin de emplear de una manera mas racional y eficaz los metodos de lucha contra las plagas de insectos, se ha recurrido a los radioisotopos y a las radiaciones. Los radioisotopos y las radiaciones son auxiliares muy utiles para mejorar los metodos de lucha contra los insectos daninos. Su empleo requiere un estudio detallado de toda una serie de cuestiones de bioecologfa, toxicologia, etc. En bioecologfa, la marcacion, de los insectos es una tecnica muy prometedora. El empleo de los radioisotopos a fin de marcar a los insectos daninos para los cultivos de cereales (Eurygaster integriceps de los radioisotopos a fin de marcar a los insectos daninos para los cultivos de cereales (Eurygaster integriceps Put, Hadena sordida Skh), y a sus parasitos ( Meniscus agnatus Crow, Pseudogonia cinerascens Rond) ha permitido calcular la extension de las migraciones, delimitar los reservorios, evaluar la importancia de las poblaciones y estudiar el modo de

  10. About the problem of the delays between particles belonging to the cosmic radiation; Sur le probleme des retards entre des particules appartenant au rayonnement cosmique

    Rogozinski, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1953-07-01

    After having examined briefly the problem of the delays who can appear between particles of high energy, issued of a same mother particle, we studied in a more details the case of the loaded particles, loosing their energy by ionization. The delay that settles between two particles of mass M belonging to this last species is defined by the difference between the times that they take to do the same distance. In the vacuum, the delays can reach any values. But, when the particles diffuse themselves in a middle absorbing, the delays stretch toward a definite limit whatever the initial energies of the particles is. One demonstrates that the maximum delay is given by ({delta}t){sub max} {approx_equal} 0,6 E{sub 0} / cK{sub min}, where E{sub 0} = Mc{sup 2} represents the energy to the rest of the particle and K{sub min} the minimum loss of energy by cm of course in the given middle. For example, in the case of the protons crossing different absorbing surroundings, the values of ({delta}t){sub max} for air (Tpn), water, the Al and the Pb are respectively equal to 8,3.10{sup -6}, 9,7.10{sup -9}, 45.10{sup -9} and 1,6 10{sup -9} dry. The corresponding values of ({delta}t){sub max} for the electrons, are the order of 10{sup -9} dry for air and the order of 10{sup -12} dry for the condensed surroundings. It results that, if the particles belonging has a sheaf demonstrated between them of the superior delays to those that are indicate, the fact would constitute a sufficient proof of the existence of heavy particles to the breast of the sheaf. Otherwise, the relation that joins ({delta}t){sub max} to the mass M could act as basis to a method of mass spectrography of the big energy particles. (author) [French] Apres avoir examine succintement le probleme des retards qui peuvent apparaitre entre des particules de grande energie, issues d'une meme particule mere, on etudie d'une facon plus detaillee le cas des particules chargees, ne perdant leur energie que par ionisation. Le

  11. Measurement and analysis of high energy radiation through activation detectors. Application in dosimetry; Sur la mesure et l'analyse des rayonnements de haute energie par detecteurs a activation. Application a la dosimetrie

    Sklavenitis, L. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-10-15

    This work is concerned with the possibility of measurement and analysis of radiation fluences within objects of small volume submitted to a high energy proton beam. The first part, consecrated to the establishment of a method of analysis, comprises a detailed study of the radiation nature and energy spectra as well as of the various dosimetry methods. In order to select a group of detectors, high energy nuclear reactions were systematically studied and for some of them cross sections were measured or calculated: for example the cross section of the reaction {sup 11}B (p,n) {sup 11}C between 150 and 3000 MeV and of the reaction {sup 34}S (p,2pn) {sup 32}P between 50 and 3000 MeV. The second part is relative to the application of the fore-mentioned analysis to radiation within a tissue equivalent phantom irradiated by 3 GeV protons. This analysis is sufficiently detailed to allow the reconstitution of the absorbed doses, the dose equivalent and, contingent on a better knowledge of the dose due to heavy particles, the quality factors. It allowed also to follow the evolution of the various dosimetric data as a function of the depth inside the phantom and to verify calculations already done by other researchers. The comparison of the measured doses and the corresponding detector activities revealed the possibility that some detectors could give directly the absorbed dose, or even the dose equivalent, by a simple activity measurement. (author) [French] Le travail porte sur la possibilite de mesure et d'analyse, a l'aide de detecteurs a activation, des fluences de rayonnements a l'interieur d'un objet de petit volume soumis a un faisceau de protons de tres haute energie. La premiere partie, consacree a la mise au point de la methode d'analyse des fluences, comporte une etude detaillee de la nature des rayonnements et de leurs spectres energetiques ainsi que des differentes methodes de dosimetrie. Pour arriver au choix d'un groupe de

  12. Cobalt-60 and Caesium-137 Gamma Sources; Sources de rayonnement gamma au cobalt-60 et au cesium-137; Gamma-istochniki iz kobal'ta-605 i tseziya-137; Fuentes gamma de cobalto-60 y de cesio-137

    Kulish, E E; Fradkin, G M [Academy of Sciences of the USSR, Moscow, Union of Soviet Socialits Republics (Russian Federation)

    1960-07-15

    The paper gives the main technical characteristics of gamma sources produced in the USSR using cobalt-60 and caesium-137 and discusses some of the problems of their production technology. The paper contains information on the radiation spectra of Co{sup 60} and Cs{sup 137} and of the source material from which they are prepared. Data are given on the dependence of the activity of cobalt sources upon the intensity of the neutron beam and the geometrical size of the sample. The yield of caesium by uranium fission is also analyzed. The problem of hermetic sealing of the sources is discussed and a complete nomenclature of all the sources manufactured in the USSR are listed, their size and activity also being indicated. In conclusion a comparison of Co{sup 60} and Cs{sup 137} sources is made. (author) [French] Cette communication expose les caracteristiques techniques fondamentales des sources de rayonnement gamma a base de cobalt-60 et de cesium-137 pro- duites en URSS; on y examine egalement certaines questions relatives a la technologie de leur production. La communication contient des donnees sur la nature du rayonnement des isotopes {sup 60}Co et {sup 137}Cs, ainsi que sur celle des matieres brutes utilisees pour leur preparation. On donne les resultats obtenus lors de l'etude de la variation de l'activite des sources au cobalt en fonction de la valeur du flux de neutrons et des dimensions geometriques de l'echantillon, ainsi que les resultats relatifs a la valeur du rendement en isotopes de cesium lors de la fission des noyaux d'uranium. On etudie ensuite les procedes pour assurer l'hermeticite de ces sources. Suit une nomenclature complete des sources produites en URSS, comportant des indications sur leurs dimensions geometriques et sur les valeurs de leur activite. Enfin, il est procede a une comparaison des sources au {sup 60}Co et au {sup 137}Cs. (author) [Spanish] En este informe se describen las principales caracteristicas tecnicas de las fuentes gamma de

  13. Measurement and analysis of high energy radiation through activation detectors. Application in dosimetry; Sur la mesure et l'analyse des rayonnements de haute energie par detecteurs a activation. Application a la dosimetrie

    Sklavenitis, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-10-15

    This work is concerned with the possibility of measurement and analysis of radiation fluences within objects of small volume submitted to a high energy proton beam. The first part, consecrated to the establishment of a method of analysis, comprises a detailed study of the radiation nature and energy spectra as well as of the various dosimetry methods. In order to select a group of detectors, high energy nuclear reactions were systematically studied and for some of them cross sections were measured or calculated: for example the cross section of the reaction {sup 11}B (p,n) {sup 11}C between 150 and 3000 MeV and of the reaction {sup 34}S (p,2pn) {sup 32}P between 50 and 3000 MeV. The second part is relative to the application of the fore-mentioned analysis to radiation within a tissue equivalent phantom irradiated by 3 GeV protons. This analysis is sufficiently detailed to allow the reconstitution of the absorbed doses, the dose equivalent and, contingent on a better knowledge of the dose due to heavy particles, the quality factors. It allowed also to follow the evolution of the various dosimetric data as a function of the depth inside the phantom and to verify calculations already done by other researchers. The comparison of the measured doses and the corresponding detector activities revealed the possibility that some detectors could give directly the absorbed dose, or even the dose equivalent, by a simple activity measurement. (author) [French] Le travail porte sur la possibilite de mesure et d'analyse, a l'aide de detecteurs a activation, des fluences de rayonnements a l'interieur d'un objet de petit volume soumis a un faisceau de protons de tres haute energie. La premiere partie, consacree a la mise au point de la methode d'analyse des fluences, comporte une etude detaillee de la nature des rayonnements et de leurs spectres energetiques ainsi que des differentes methodes de dosimetrie. Pour arriver au choix d'un groupe de detecteurs, une etude systematique des

  14. Measurement of the activity of beta emitting gases using an ionisation chamber; Mesure de l'activite des gaz emetteurs beta au moyen d'une chambre d'ionisation

    Lebouleux, P [Commissariat a l' Energie Atomique. Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)

    1962-07-01

    An ionization chamber was developed for measuring directly the activity of a {beta}-emitting gas whatever the gas may be. The following two parameters are defined and determined: p, the average specific ionization produced by a {beta} disintegration, and i, the average {beta} path in the chamber. It was shown, during the determination of i, that the {beta} particles are reflected on the walls of the ionization chamber when the latter are made of a high atomic number material. It was possible to eliminate this effect by constructing an electrode chamber made of graphite. With this chamber a direct measurement can be made of the activity of a gaseous {beta} emitter with a precision of about {+-}10%. Some applications are given of the graphite electrode chamber (calibration of the chambers built industrially and determination of the activation cross section of a gaseous emitter). It was possible to determine the activation cross section of {sup 134}Xe; a value of 0.18 {+-} 0.03 barn was found. (author) [French] Le but de l'etude est de realiser une chambre d'ionisation permettant d'effectuer une mesure directe de l'activite d'un gaz emetteur {beta} quel que soit l'emetteur considere. On definit et l'on determine les deux parametres suivants: p: ionisation specifique moyenne produite par une desintegration {beta}. La determination est effectuee par une methode graphique, i: moyenne des parcours des {beta} dans la chambre. La determination est effectuee experimentalement par introduction dans la chambre d'un gaz radioactif dont on peut calculer l'activite. On a mis en evidence, au cours de la determination de i, la reflexion des particules {beta} sur les parois des chambres d'ionisation lorsque celles-ci sont constituees d'un materiau de numero atomique eleve. La construction d'une chambre a electrodes de graphite nous a permis d'eliminer ce phenomene. Avec cette chambre, on effectue une mesure directe de l'activite d'un emetteur {beta} gazeux avec une precision de l

  15. Emergency measures and treatment in the event of accidental aver exposure to radiation or of radioactive contamination; Mesures d'urgence et traitement en cas de surexposition accidentelle aux rayonnements ou en cas de contamination radioactive

    Jammet, H [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    In the first part the author presents an overall view of emergency measures to be applied in the case of internal or external radioactive contamination. He states in particular, in these two cases, the methods by which it is possible to eliminate the contaminating radioactive substances from the organism. The author then considers the therapeutic methods to be adopted in the case of an accident of overexposure to radiation, distinguishing between the case of a partial irradiation and that of an acute total irradiation. There will be essentially three methods used depending on the physical measures carried out (irradiation, conditions, estimation of the dose received) and of the clinical data collected: particular treatments, treatment for helping the organism during its return to normal activity, temporary or permanent replacement of the organs affected. (author) [French] L'auteur presente, en une premiere partie, une vue d'ensemble des mesures d'urgence a appliquer en cas de contamination radioactive externe ou interne. Il fait etat en particulier, dans ces deux cas, des methodes permettant de debarrasser l'organisme des substances radioactives contaminantes. L'auteur envisage, ensuite, la therapeutique a adopter lors d'un accident de surexposition aux rayonnements, distinguant le cas d'une irradiation partielle et celui d'une irradiation totale aigue. Trois traitements seront essentiellement mis en oeuvre en fonction des mesures physiques effectuees (conditions d'irradiation, evaluation de la dose recue) et des donnees cliniques recueillies: traitements specifiques, traitement de soutien de l'organisme preparant la restauration, suppleance temporaire ou definitive d'organes defaillants. (auteur)

  16. Germanium junction detectors. Theoretical and practical factors governing their use in radiation spectrometry; Detecteurs a jonction au germanium. Elements theoriques et pratiques pour l'utilisation en spectrometrie de rayonnements

    Hors, M; Philis, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-07-01

    Semi-conductor detectors have recently greatly increased the possibilities available to nuclear spectroscopists for the study of {alpha}, {beta} and {gamma} radiations. Their use in radio-chemistry has encouraged us to study their principle, their mechanism and also the conditions under which they can be used. The first part, which is theoretical, consists of a summary of what should be known concerning the best use of junction detectors, in particular Ge (Li) detectors. The second part, which is experimental, summarizes the laboratory work carried out over a period of one year on Ge (Li) detectors. Stress is laid on the possibilities presented by the use of these detectors as photo-electric spectrometers, and also on the precautions required. Amongst the numerous results presented, the resolution of 2.52 keV obtained for the {gamma} radiation of 145.5 keV for {sup 141}Ce may be particularly noted. (authors) [French] Les detecteurs a semi-conducteurs ont recemment accru les possibilites offertes aux spectroscopistes nucleaires pour l'etude des radiations {alpha}, {beta}, {gamma}. Leurs utilisations en radiochimie nous ont incite a en etudier le principe, le mecanisme et d'autre part les conditions d'emploi. La premiere partie, theorique, rappelle l'essentiel de ce qu'il est utile de connaitre pour une utilisation optimale des detecteurs a jonctions et en particulier des detecteurs Ge (Li). La deuxieme partie, experimentale, resume les travaux realises au laboratoire pendant un an avec des detecteurs Ge (Li). Nous insistons sur les possibilites offertes et les precautions a prendre dans l'utilisation de ces detecteurs comme spectrometres photoelectriques. Parmi les nombreux resultats presentes, citons la resolution de 2,52 keV obtenue pour le rayonnement {gamma} de 145 f5 keV du {sup 141}Ce. (auteurs)

  17. Determination of the cross-sections of some nuclear reactions occurring as a result of cosmic radiation (1963); Determination des sections efficaces de quelques reactions nucleaires intervenant dans les effets ou rayonnement cosmique (1963)

    Tamers, M A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1962-06-15

    The high energy reactions studied during this research are reactions liable to occur as a result of cosmic radiation. On the one hand the reaction {sup 16}O(p, 3p){sup 14}C was studied and its cross-section measured between 65 MeV and 2.7 GeV; a value of 2.3 mb {+-} 0.5 was found. These values have mode it possible to forecast measurable quantities of carbon-14 in meteorites and also to measure them. On the other hand the reactions {sup 12}C({sup 16}O...), {sup 12}C({sup 14}N...) and {sup 12}C({sup 12}C...) have been studied and an attempt has been made to explain the mechanism of these reactions. (author) [French] Les reactions a hautes energies qui ont ete etudiees au court de ce travail sont des reactions susceptibles de se produire sous l'effet du rayonnement cosmique. Il s'agit d'une part de la reaction {sup 16}O(p, 3p){sup 14}C dont on a mesure la section efficoce egale a 2,3 mb {+-} 0,5 entre 65 MeV et 2,7 GeV. Ces valeurs ont permis de prevoir des quantites mesurables de carbone 14 dans les meteorites et par suite de les determiner. D'autre part les reaction {sup 12}C({sup 16}O...), {sup 12}C({sup 14}N...) et {sup 12}C({sup 12}C...) ont ete etudiees et on a tente d'expliquer le mecanisme de ces reactions. (auteur)

  18. Emergency measures and treatment in the event of accidental aver exposure to radiation or of radioactive contamination; Mesures d'urgence et traitement en cas de surexposition accidentelle aux rayonnements ou en cas de contamination radioactive

    Jammet, H. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    In the first part the author presents an overall view of emergency measures to be applied in the case of internal or external radioactive contamination. He states in particular, in these two cases, the methods by which it is possible to eliminate the contaminating radioactive substances from the organism. The author then considers the therapeutic methods to be adopted in the case of an accident of overexposure to radiation, distinguishing between the case of a partial irradiation and that of an acute total irradiation. There will be essentially three methods used depending on the physical measures carried out (irradiation, conditions, estimation of the dose received) and of the clinical data collected: particular treatments, treatment for helping the organism during its return to normal activity, temporary or permanent replacement of the organs affected. (author) [French] L'auteur presente, en une premiere partie, une vue d'ensemble des mesures d'urgence a appliquer en cas de contamination radioactive externe ou interne. Il fait etat en particulier, dans ces deux cas, des methodes permettant de debarrasser l'organisme des substances radioactives contaminantes. L'auteur envisage, ensuite, la therapeutique a adopter lors d'un accident de surexposition aux rayonnements, distinguant le cas d'une irradiation partielle et celui d'une irradiation totale aigue. Trois traitements seront essentiellement mis en oeuvre en fonction des mesures physiques effectuees (conditions d'irradiation, evaluation de la dose recue) et des donnees cliniques recueillies: traitements specifiques, traitement de soutien de l'organisme preparant la restauration, suppleance temporaire ou definitive d'organes defaillants. (auteur)

  19. Field studies on long term ecosystem consequences of ionising radiation and chemical pollutants (EANOR Project)

    Oughton, D. [Centre for Environmental Radioactivity - CERAD (Norway); Evseeva, T. [Institute of Biology RAS (Russian Federation); Erenturk, S. [Istanbul Technical University (Turkey)

    2014-07-01

    -barcoding, invertebrate DNA barcoding, DNA methylation, and other molecular endpoints is ongoing, together with studies of possible adaptation of plants, invertebrates and microorganisms. Preliminary results show significant differences in diversity for many species between contaminated and reference sites. However, more research is needed to draw conclusions about the cause of such observations. Nevertheless, by combining a through site characterisation and exposure assessment with a variety of ecologically relevant biomarker and endpoint measurements, the data produced should be a valuable contribution to international activities looking at the impacts of chronic exposure of ionising radiation on non-human species. Project participants: Elena Belykh, Anna Kaneva, Boris Kondratenok, Alla Kolesnikova, Alexey Kurdin, Tatinana Majstrenko, Taskayeva Anastasia Oleshya Vakhrusheva, Illa Velegzhaninov, Vladimir Zainullin (IoB, Komi Republic, Russia); S. Haciyakupoglu (Istanbul Technical University, Turkey); Rahime Oral, Sabriye Yusan, Filiz Gur Filiz (Ege University, Turkey); Murat Belivermis, Onder Kilic (Istanbul University, Turkey); Fatma Kocbas (Celal Bayar University, Turkey); Mustafa Akiner, (Rize University, Turkey); Claire Coutris, Erik Joner (Bioforsk, Norway); Turid Hertel-Aas, Emmanuel Lapied, Yevgeniya Tomkiv, Brit Salbu, Lindis Skipperud (Centre for Environmental Radioactivity, UMB, Norway). Document available in abstract form only. (authors)

  20. Theoretical and Applied Aspects of Radiation D-Values for Spores of Clostridium Botulinum; Aspects Theoriques et Pratiques des Valeurs D de Rayonnement Appliquees aux Spores de Clostridium Botulinum; Teoreticheskie i prikladnye aspekty koehffitsienta izlucheniya odlya spor Clostridium Botulinum; Aspectos Teoricos y Practicos de los Valores D para Esporas del Clostridium Botulinum

    Grecz, N. [Biophysics Laboratory, Illinois Institute Of Technology, Chicago, IL (United States)

    1966-11-15

    suspending medium may either compete for radicals, e.g. most foods and microbiological media are radical scavengers, or it may promote formation of harmful radicals, e. g. phosphate buffer forms phosphinic acid, oxygen forms peroxy and perhydroxye radicals. Changes of D{sub 10}-values of an individual strain caused by various environmental conditions can be related to indirect effects, while changes of D{sub 10} values from strain to strain under standardized conditions relate to the amount and structure of nucleoid DNA in spores. In this respect all strains of C. botulinum studied to date can be tentatively divided into three groups: Group 1 includes strains (A, B and E) with D values around 0.13 Mrad or less. These spores exhibit single-hit inactivation curves and have probably one chromosome with a low repair probability. Group 2 includes strains 12885 A, 62A, 77A, 9B clustering around D{sub 10} =0.23 Mrad. Available target data suggest that these spores possess one chromosome of 900 {mu} with a repair multiplicity of 13. Group 3 includes the highly-resistant strains 33A, 36A, 40B, 41B, and 53B clustering around D{sub 10} = 0.33 Mrad. Available target data suggest that these spores possess two chromosomes of 900{mu} each with a repair multiplicity (N) between 80 and 90, i.e. N = 13{sup 2}/2. (author) [French] Il a ete constate que les spores de C. botulinum offrent aux rayonnements ionisants une resistance qui est egale ou superieure a celle des spores d'autres organismes non toxiques provoquant l'alterration des denrees alimentaires. Pour cette raison, les normes de traitement microbiologique appliquees pour la conservation des aliments par les rayonnements sont toujours fonction de la radioresistance des spores de C. botulinum. L'indice de cette radioreistance est la valeur Dio definie comme la dose necessaire pour inactiver un cycle logarithmique (90%) d'une population de spores donnee, tandis que le terme 12 x D a ete arbitrairement defini comme la dose sure pour la

  1. Câbles électriques - Calcul du courant admissible - Partie 2: Résistance thermique - Section 2: Méthode de calcul des coefficients de réduction de l'intensité de courant admissible pour des groupes de câbles posés à l'air libre et protégés du rayonnement solaire direct

    1995-01-01

    Câbles électriques - Calcul du courant admissible - Partie 2: Résistance thermique - Section 2: Méthode de calcul des coefficients de réduction de l'intensité de courant admissible pour des groupes de câbles posés à l'air libre et protégés du rayonnement solaire direct

  2. Characterisation of chemical components for identifying historical Chinese textile dyes by ultra high performance liquid chromatography – photodiode array – electrospray ionisation mass spectrometer

    Han, J.; Wanrooij, J.; van Bommel, M.; Quye, A.

    2017-01-01

    This research makes the first attempt to apply Ultra High Performance Liquid Chromatography (UHPLC) coupled to both Photodiode Array detection (PDA) and Electrospray Ionisation Mass Spectrometer (ESI–MS) to the chemical characterisation of common textile dyes in ancient China. Three different

  3. Identification of Wheat Varieties Using Matrix-assisted Laser Desorption/Ionisation Time-of-flight Mass Spectrometry and an Artificial Neural network

    Bloch, Helle Aagaard; Kesmir, Can; Petersen, Marianne Kjerstine

    1999-01-01

    A novel tool for variety identification of wheat (Triticum aestivum L,) has been developed: an artificial neural network (ANN) is used to classify the gliadin fraction analysed by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOFMS). The robustness...

  4. The Swedish radiation protection institute's regulations on general obligations in medical and dental practices using ionising radiation; issued on April 28, 2000

    NONE

    2000-04-01

    These regulations are applicable to medical and dental practices with ionising radiation used for medical exposures. The regulations are also applicable to exposures of persons who knowingly and willingly, other than as part of their occupation, support and comfort patients undergoing medical exposure.

  5. Influence of SNP Polymorphisms in DNA Repair Genes on the Level of Persistent Damage in Human Lymphocytes After Exposure to 2 Gy of Ionising Radiation

    Milic, M.; Rozgaj, R.; Kasuba, V.; Kubelka, D.; Angelini, S.; Hrelia, P.

    2011-01-01

    Variation in cell response to ionising radiation could be result of changes in gene expression and/or polymorphisms of DNA repair genes. The aim of the study was to estimate the DNA damage level in human lymphocytes after exposure to 2 Gy of ionising radiation. Medical workers occupationally exposed to low doses of ionising radiation (N = 20) and matched controls (N 20) were genotyped for polymorphic hOGG1, XRCC1, APE1, XPD10, XPD23, XRCC3, PARP1 and MGMT genes. Micronucleus (MN) test was used for the estimation of DNA damage before and after radiation. Incidence of MN in irradiated samples positively correlated with age and negatively with polymorphic variants of XPD23. Significant difference was observed between irradiated homozygotes (HO) and heterozygotes (HE). HO and HE APE1 differed in MN before exposure. HO and polymorphic variants of XPD10 differed in MN after exposure. Gender showed different MN in the exposed group after exposure. Age correlated positively with MN after exposure, working probation and received dose. Multiple regression analysis revealed connection between polymorphic variants of APE1 and XRCC3 with MN before exposure. These results confirm the value of micronucleus assay in DNA damage estimation and suggest possible use of polymorphic genes in monitoring of individuals professionaly exposed to ionising radiation. (author)

  6. Lemna minor plants chronically exposed to ionising radiation: RNA-seq analysis indicates a dose rate dependent shift from acclimation to survival strategies.

    Van Hoeck, Arne; Horemans, Nele; Nauts, Robin; Van Hees, May; Vandenhove, Hildegarde; Blust, Ronny

    2017-04-01

    Ecotoxicological research provides knowledge on ionising radiation-induced responses in different plant species. However, the sparse data currently available are mainly extracted from acute exposure treatments. To provide a better understanding of environmental exposure scenarios, the response to stress in plants must be followed in more natural relevant chronic conditions. We previously showed morphological and biochemical responses in Lemna minor plants continuously exposed for 7days in a dose-rate dependent manner. In this study responses on molecular (gene expression) and physiological (photosynthetic) level are evaluated in L. minor plants exposed to ionising radiation. To enable this, we examined the gene expression profiles of irradiated L. minor plants by using an RNA-seq approach. The gene expression data reveal indications that L. minor plants exposed at lower dose rates, can tolerate the exposure by triggering acclimation responses. In contrast, at the highest dose rate tested, a high number of genes related to antioxidative defense systems, DNA repair and cell cycle were differentially expressed suggesting that only high dose rates of ionising radiation drive L. minor plants into survival strategies. Notably, the photosynthetic process seems to be unaffected in L. minor plants among the tested dose rates. This study, supported by our earlier work, clearly indicates that plants shift from acclimation responses towards survival responses at increasing dose rates of ionising radiation. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. The Swedish radiation protection institute's regulations on general obligations in medical and dental practices using ionising radiation; issued on April 28, 2000

    2000-04-01

    These regulations are applicable to medical and dental practices with ionising radiation used for medical exposures. The regulations are also applicable to exposures of persons who knowingly and willingly, other than as part of their occupation, support and comfort patients undergoing medical exposure

  8. A search for non-baryonic dark matter using an ionisation bolometer in the edelweiss experiment; Recherche de matiere sombre non-baryonique au moyen d`un bolometre a ionisation dans le cadre de l`experience edelweiss

    Di Stefano, Ph [CEA Saclay, 91 - Gif-sur-Yvette (France). Dept. d` Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l` Instrumentation Associee; [Paris-11 Univ., 91 - Orsay (France)

    1998-09-24

    The EDELWEISS experiment is an underground direct-detection search for hypothetical supersymmetric WIMPs that might solve the problem of dark matter. We have employed a cryogenic 70 g germanium ionisation bolometer, in which a WIMP would scatter elastically off a nucleus, creating both a heat and an ionisation signal. To offset the various electronic noises present in our necessarily small signals, we have s applied an optimal filtering technique in the frequency domain. This allows us to reach resolutions of 1.2 keV FWHM at 122 keV on north channels. It also provides good separation right down to low energies between the expected signal of nuclear recoils, and the photonic background of electron recoils which ionize more for a given energy. Calibration data show that we are able to reject 99.7 % of this background, while keeping 95% of the signal. However, our 1.17 kg.days of data searching for WIMPs show a third population encroaching on the expected signal. This is probably due to low energy photons or electrons interacting in the outer layers of the crystal, where charges are incompletely collected. Nevertheless, by trading off half of the conserved signal, we still manage to reject 98.5 % of the background. Thus the raw rate of 40 evts/d/kg/keV yields a conservative 90 % upper limit on the signal of 0.6 evts/d/kg/keV. This represents nearly a three orders of magnitude improvement for EDELWEISS, and puts the predicted supersymmetric phase space within two orders of magnitude. (author) 196 refs.

  9. Method for determining the irradiation dose deposited in a scintillator by ionising radiation and associated device - WO 2013060745 A1

    2013-01-01

    The invention relates to a method for determining an irradiation dose deposited in a scintillator (5) by ionising radiation, said method comprising the steps of: irradiating the scintillator (5) for a pre-determined time; detecting an instant at which the scintillator (5) is excited, using a first photodetector (11); subsequently, detecting an instant at which a scintillation photon is received, using a second photodetector (14) operating in single photon counting mode; identifying each sequence formed by the detection of an excitation instant by the first photodetector (11) and the detection of a reception instant by the second photodetector (14) at a coincidence event; counting the number of coincidence events; and obtaining the irradiation dose deposited during the irradiation time as a function of the number of coincidence events counted and a pre-determined proportionality factor. (authors)

  10. Electrospray ionisation mass spectrometry facilitates detection of fibrinogen (Bbeta 14 Arg --> Cys) mutation in a family with thrombosis.

    Brennan, S O; Hammonds, B; Spearing, R; George, P M

    1997-12-01

    We report the first direct detection of a fibrinogen mutation by electrospray ionisation mass spectrometry. The propositus, from a family with a history of thrombosis, came to attention after a pulmonary embolism subsequent to a spontaneous abortion. Prolonged thrombin (41 s) and reptilase times (26 s) together with an impairment of fibrinopeptide B release suggested a mutation at the thrombin cleavage site of the Bbeta chain. Direct mass analysis of purified fibrin chains from a thrombin induced clot showed that 50% of the Bbeta chains remained uncleaved. The measured mass of the mono sialo isoform of this uncleaved chain was 54150 Da, compared to a value of 54198 Da for normal Bbeta chains. This decrease of 48 Da in the intact protein is indicative of either a Bbeta 14 Arg to Cys, or Arg to Leu substitution. Heterozygosity for the Bbeta 14 Arg --> Cys mutation was verified by PCR amplification and DNA sequence analysis.

  11. Fourth IRMF comparison of calibrations of portable gamma-ray dose- rate monitors 2001-2002 Ionising radiation

    Lewis, V E

    2002-01-01

    The Ionising Radiations Metrology Forum (IRMF) organised a fourth comparison of calibrations of gamma-ray dose-rate monitors in which fifteen establishments in the UK participated. The exercise involved the circulation of three gamma-ray monitors for calibration in the fields produced using sup 1 sup 3 sup 7 Cs, sup 2 sup 4 sup 1 Am and sup 6 sup 0 Co. The instruments used were an Electra with MC 20 probe, a Mini-Instruments Mini-rad 1000 and a Siemens electronic personal dosemeter Mk 2 (EPD). The responses relative to 'true' dose equivalent rate were calculated by the individual participants and submitted to the for analysis along with details of the facilities and fields employed. Details of the estimated uncertainties were also reported. The results are compared and demonstrate generally satisfactory agreement between the participating establishments. However, the participants' treatment of uncertainties needs improvement and demonstrates a need for guidance in this area.

  12. Matrix-assisted laser desorption/ionisation mass spectrometry imaging and its development for plant protein imaging

    Millar A Harvey

    2011-07-01

    Full Text Available Abstract Matrix-Assisted Laser Desorption/Ionisation (MALDI mass spectrometry imaging (MSI uses the power of high mass resolution time of flight (ToF mass spectrometry coupled to the raster of lasers shots across the cut surface of tissues to provide new insights into the spatial distribution of biomolecules within biological tissues. The history of this technique in animals and plants is considered and the potential for analysis of proteins by this technique in plants is discussed. Protein biomarker identification from MALDI-MSI is a challenge and a number of different approaches to address this bottleneck are discussed. The technical considerations needed for MALDI-MSI are reviewed and these are presented alongside examples from our own work and a protocol for MALDI-MSI of proteins in plant samples.

  13. Thermally and optically stimulated luminescence of AlN-Y2O3 ceramics after ionising irradiation

    Trinkler, L.; Bos, A.J.J.; Winkelman, A.J.M.

    1999-01-01

    , an essential drawback of AlN-Y2O3 is its high fading rate. Special attention has been focused on understanding and improving the fading properties. In particular, the influence of the ceramics production conditions and the additive concentration on the fading rate have been studied. Experimental results......Thermally (TL) and optically stimulated luminescence (OSL) were studied in AlN-Y2O3 ceramics after irradiation with ionising radiation. The extremely high TL sensitivity (approximately 60 times the sensitivity of LiF:Mg,Tl (TLD-100)) makes AlN-Y2O3 ceramics attractive as a TLD material. However...... on spectral properties and thermal evolution of OSL are also presented. The stimulation spectrum covers the spectral range from green to infrared light. A combination of thermal and optical stimulation allowed a correlation to be found between parameters of OSL and TL after the same irradiation dose...

  14. Excitation of low-frequency residual currents at combination frequencies of an ionising two-colour laser pulse

    Vvedenskii, N. V.; Kostin, V. A.; Laryushin, I. D.; Silaev, A. A.

    2016-05-01

    We have studied the processes of excitation of low-frequency residual currents in a plasma produced through ionisation of gases by two-colour laser pulses in laser-plasma schemes for THz generation. We have developed an analytical approach that allows one to find residual currents in the case when one of the components of a two-colour pulse is weak enough. The derived analytical expressions show that the effective generation of the residual current (and hence the effective THz generation) is possible if the ratio of the frequencies in the two-colour laser pulse is close to a rational fraction with a not very big odd sum of the numerator and denominator. The results of numerical calculations (including those based on the solution of the three-dimensional time-dependent Schrödinger equation) agree well with the analytical results.

  15. Comparative evaluation of different approaches to environmental protection against ionising radiation in view of practicability and consistency

    Steiner, M.; Hornung, L.; Mundigl, S.; Kirchner, G.

    2006-01-01

    International organisations, including ICRP, IAEA and UNSCEAR, and the international scientific community are currently engaged in work on the protection of non-human species against ionising radiation as a complement to the existing framework centred on humans. The basic ideas and conceptual approaches developed during the last decade substantially agree with each other. The EC funded FASSET project (Framework for Assessment of Environmental Impact) summarizes and reviews the current knowledge of radiation effects on biota, provides basic dosimetric models for fauna and flora and suggests an assessment framework. Protection of the environment against ionising radiation, on the one hand, aims to close a conceptual gap in radiation protection. Therefore, current frameworks for environmental protection conceptually follow radiation protection of man. On the other hand, preservation of natural resources, habitats and the biological diversity are common objectives of environmental protection against radioactive as well as chemical pollutants, suggesting an integrated approach based on the fundamental ideas of conventional environmental protection. In essence, a conceptual framework encompassing protection of man as well as of fauna and flora against chemical and radioactive pollutants would be highly desirable in view of coherence, consistency and transparency. Such an umbrella concept communicates the positive message that similar issues are treated in a conceptually similar manner, thus facilitating scientific justification and public communication and increasing acceptance. This paper discusses different concepts and approaches to radiation protection of man, radiation protection of non-human biota and environmental protection against chemical pollutants, identifies common principles and differences, addresses conflicting requirements and evaluates the feasibility and limitations of such an encompassing framework. (authors)

  16. An overview of the ERICA Integrated Approach to the assessment and management of environmental risks from ionising contaminants

    Larsson, Carl-Magnus

    2008-01-01

    The ERICA project (environmental risks from ionising contaminants: assessment and management, EC contract no. FI6R-CT-2004-508847) concluded with the publication of two main outputs: the ERICA Integrated Approach to the assessment and management of environmental risks from ionising radiation, of which also introduces the user to the second main output, the ERICA Tool, which is a software programme with supporting databases, that together with its associated help will guide users through the assessment process. More than 60 European scientists contributed to the ERICA Integrated Approach. In addition, a large number of experts, policy makers, and decision-makers in different areas have contributed views on the ERICA Integrated Approach and its associated Tool from the user's perspective, through participation in the End-Users Group set up under the ERICA project. Databases on transfer, dose conversion coefficients and radiation effects on biota have been developed specifically for the purpose of the Integrated Approach, and incorporated into, or interacting with, the Tool. Species sensitivity distributions of biological effects data have been performed and did not reveal, for chronic exposure, any statistical grounds for separation between terrestrial, marine and freshwater ecosystems in terms of species sensitivity to radiation; on the basis of such analysis a universal screening dose rate criterion of 10 μGy h -1 incremental dose rate is suggested for exiting the assessment procedure while being confident that environmental risks are negligible. This criterion is used for the two first tiers (conservative assessment with limited data requirement and various possibilities of incorporating user-defined parameter values, including the screening dose rate criterion) of the assessment methodology. Exposure situations of concern are carried through a third tier, making use of all relevant databases and with a number of issues and options listed to support and guide

  17. Measurement of small ion beams by thermal ionisation mass spectrometry using new 1013 Ohm resistors

    Koornneef, J.M.; Bouman, C.; Schwieters, J.B.; Davies, G.R.

    2014-01-01

    Highlights: • First data are presented using 10 13 Ohm resistors connected to Faraday collectors. • 5 prototype 10 13 Ohm resistors were installed in a TRITON-Plus TIMS. • Performance was tested by measuring Sr and Nd isotope ratios on  13 Ohm resistors perform better than ion counting and 10 11 Ohm resistors. • Fourth decimal variability can be resolved for Nd isotope ratios on 10 pg samples. - Abstract: We tested 5 newly manufactured – prototype – 10 13 Ohm resistors in the feedback loop of Faraday cup amplifiers to measure small ion beams by Thermal Ionisation Mass Spectrometry (TIMS). The high Ohmic resistors installed in the TRITON Plus at the VU University Amsterdam theoretically have 10 times lower noise levels relative to the default 10 11 Ohm resistors. To investigate the precision and accuracy of analyses using these new amplifiers we measured Sr and Nd isotopes of reference standards at a range of ion currents (3.2 × 10 −16 to 1 × 10 −12 A, corresponding to intensities of 32 μV to 100 mV on a default 10 11 Ohm amplifier) and on small amounts of material (100 and 10 pg). Internal precision and external reproducibility for Sr and Nd isotope ratios are both better when collected on 10 13 compared 10 12 Ohm resistors and to the default 10 11 Ohm resistors. At an 87 Sr ion current of 3 × 10 −14 A (3 mV on a 10 11 Ohm amplifier) the internal precision (2 SE) of 87 Sr/ 86 Sr is 5 times better for 10 13 Ohm resistors compared to 10 11 Ohm resistors. The external reproducibility (2 SD) at this beam intensity is 9 times better. Multiple 100 and 10 pg Sr standards, ran to exhaustion, yielded low 87 Sr/ 86 Sr compared to the long term average (e.g. 10 pg average = 0.710083 ± 164 (n = 11) instead of 0.710244 ± 12, n = 73). The average off-set for 10 pg standards can be explained by a loading blank contribution of 1.3 pg. In contrast, Nd data on 100 pg and 10 pg samples are accurate suggesting that Nd loading blanks do not compromise the

  18. Theoretical galactic cosmic ray electron spectrum obtained for sources of varying geometry; Spectre theorique des electrons du rayonnement cosmique dans la galaxie obtenu pour des sources a geometrie variable

    Cohen, M E [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-07-01

    Jokipii and Meyer have recently obtained an electron density energy spectrum of the cosmic rays, originating in the Galaxy, using integral solutions of the steady state transfer equations, by considering a circular cylindric galactic disc as source and approximating the resulting fourth order integral. In this report, we present general results, obtained by using an arbitrary circular cylindric source, without restricting ourselves to the galactic disc. The integrals are treated exactly. The conclusions of Jokipii and Meyer form special cases of these results. We also obtain an exponential energy variation which, at the moment, is not observed experimentally. The second part of this work deals with more complicated, but perhaps more realistic models of elliptic cylindric and ellipsoidal galactic disc sources. One may also note that a very large source concentrated in a very small region gives a spectrum not unlike that for a small source distributed throughout a large volume. Finally, it may be remarked that the model adopted is much less restrictive than the artificial conception of 'leakage time' followed by other workers. (author) [French] Jokipii et Meyer ont dernierement obtenu un spectre d'energie pour les electrons galactiques dans le rayonnement cosmique, en utilisant les solutions des equations de transfert, a l'etat stationnaire, ces dernieres etant sous forme d'integrales, en prenant une source completement diffusee dans le disque galactique, celui-ci etant hypothetiquement choisi comme circulaire et cylindrique et en faisant une approximation sur l'integrale du quatrieme degre. Dans ce rapport, nous presentons des resultats generaux obtenus en faisant appel a une source, diffusee dans un cylindre circulaire, arbitrairement choisi, c'est-a-dire sans nous restreindre au disque galactique comme source. Les integrales sont traitees d'une maniere exacte. Les conclusions de Jokipii et Meyer constituent des cas speciaux des resultats precedents. Nous obtenons

  19. The potential of organic (electrospray- and atmospheric pressure chemical ionisation) mass spectrometric techniques coupled to liquid-phase separation for speciation analysis.

    Rosenberg, Erwin

    2003-06-06

    The use of mass spectrometry based on atmospheric pressure ionisation techniques (atmospheric pressure chemical ionisation, APCI, and electrospray ionisation, ESI) for speciation analysis is reviewed with emphasis on the literature published in and after 1999. This report accounts for the increasing interest that atmospheric pressure ionisation techniques, and in particular ESI, have found in the past years for qualitative and quantitative speciation analysis. In contrast to element-selective detectors, organic mass spectrometric techniques provide information on the intact metal species which can be used for the identification of unknown species (particularly with MS-MS detection) or the confirmation of the actual presence of species in a given sample. Due to the complexity of real samples, it is inevitable in all but the simplest cases to couple atmospheric pressure MS detection to a separation technique. Separation in the liquid phase (capillary electrophoresis or liquid chromatography in reversed phase, ion chromatographic or size-exclusion mode) is particularly suitable since the available techniques cover a very wide range of analyte polarities and molecular mass. Moreover, derivatisation can normally be avoided in liquid-phase separation. Particularly in complex environmental or biological samples, separation in one dimension is not sufficient for obtaining adequate resolution for all relevant species. In this case, multi-dimensional separation, based on orthogonal separation techniques, has proven successful. ESI-MS is also often used in parallel with inductively coupled plasma MS detection. This review is structured in two parts. In the first, the fundamentals of atmospheric pressure ionisation techniques are briefly reviewed. The second part of the review discusses recent applications including redox species, use of ESI-MS for structural elucidation of metal complexes, characterisation and quantification of small organometallic species with relevance to

  20. Protection of the environment from ionising radiation. The development and application of a system of radiation protection for the environment. Proceedings of the third international symposium on the protection of the environment from ionising radiation (SPEIR 3). Unedited papers

    NONE

    2003-05-01

    In recent years, awareness of the vulnerability of the environment has increased, as evidenced by new and developing international policies for environmental protection, starting with the Rio Declaration of 1992. In the context of ionizing radiation, the existing international approach is largely based on providing for the protection of humans, but this is being critically reviewed in several international fora. It is in this context that the Third International Symposium on Protection of the Environment from Ionising Radiation (SPEIR 3) was held between 22 and 26 July 2002, in Darwin, Australia. The symposium focused on issues related to the development and application of a system of radiation protection for the environment. The symposium programme included sessions dedicated to: ongoing research on the effects, responses and mechanisms of the interactions of ionizing radiation with biota; policy and ethical dimensions of the development of a framework for environmental radiation protection; and the development and use of methods and models for evaluating radiation as a stressor to the environment. Three workshops were held to allow for detailed discussion of each of these subjects. This symposium was the third in a series. The first International Symposium on Ionising Radiation: Protection of the Natural Environment, was held in Stockholm, Sweden, 20-24 May 1996. This symposium was organized jointly by the Swedish Radiation Protection Institute (SSI) and the Atomic Energy Control Board (AECB) of Canada, and the proceedings were published by the Akademitryck AB, Edsbruk, Sweden in 1996. The second International Symposium on Ionizing Radiation: Environmental Protection Approaches for Nuclear Facilities, was held in Ottawa, Canada, 10-14 May 1999, and was organized by the Canadian Nuclear Safety Commission (CNSC), the Supervising Scientists Group of Environment Australia, and the Swedish Radiation Protection Institute (SSI). The proceedings were published in April