The atmosphere of Mars - Detection of krypton and xenon

Science.gov (United States)

Owen, T.; Biemann, K.; Biller, J. E.; Lafleur, A. L.; Rushneck, D. R.; Howarth, D. W.

1976-01-01

Krypton and xenon have been discovered in the Martian atmosphere with the mass spectrometer on the second Viking lander. Krypton is more abundant than xenon. The relative abundances of the krypton isotopes appear normal, but the ratio of xenon-129 to xenon-132 is enhanced on Mars relative to the terrestrial value for this ratio. Some possible implications of these findings are discussed.

Hyperpolarized 129Xe as an NMR probe for functional studies

International Nuclear Information System (INIS)

Wolber, J.

2000-01-01

The nuclear spin polarization of 129 Xe can be enhanced by several orders of magnitude using optical pumping techniques, resulting in a dramatic enhancement of the 129 Xe Nuclear Magnetic Resonance (NMR) signal. The 'hyperpolarized' gas can be used for Magnetic Resonance Imaging (MRI) of the void spaces of the lungs after introduction of the gas into the respiratory system. Furthermore, the high solubility of xenon in blood and lipids suggests the use of 129 Xe NMR for studying blood flow, permeability, perfusion and blood volume. Hyperpolarized 129 Xe MRI has the potential of combining the high sensitivity and functional information of radioactive tracer studies with the high spatial and temporal resolution of MRI. The spin-lattice relaxation time T 1 of 129 Xe in blood determines the loss of polarization during transit from the lungs to the tissue of interest. A difference in the relaxation times of xenon in oxygenated and deoxygenated blood could be used as a contrast mechanism in functional Magnetic Resonance Imaging (fMRI). In this thesis, the hyperpolarized 129 Xe T 1 in human blood is measured in vitro as a function of blood oxygenation, and the relevant relaxation mechanisms are discussed. A new and unexpected finding is that the hyperpolarized 129 Xe NMR spectrum in blood is highly sensitive to blood oxygenation. Therefore, hyperpolarized 129 Xe NMR provides a powerful means of measuring blood oxygenation quantitatively and non-invasively. The interaction of xenon with hemoglobin is responsible for an oxygen-dependent shift of the 129 Xe NMR resonance of xenon in red blood cells. Injection delivery of hyperpolarized 129 Xe in solution could be a more efficient method of administrating the gas for functional NMR studies. For this purpose, suitable biocompatible carrier media have been studied. In particular, the use of perfluorocarbon emulsions, which are already in use as blood substitutes, as delivery media for hyperpolarized 129 Xe has been investigates

Contribution to the study of nuclear resonance in magnetic media (1963); Contribution a l'etude de la resonance nucleaire dans les milieux magnetique (1963)

Energy Technology Data Exchange (ETDEWEB)

Hartmann-Boutron, F [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1963-06-15

An attempt is made to interpret the results of nuclear magnetic resonance experiments made by various workers on ferro and ferrimagnetic compounds of the iron group. The problems encountered are the following: effects of the dipolar fields and the hyperfine structure anisotropy; signal intensity; frequency pulling due to the Suhl-Nakamura interaction between nuclear spins ; nuclear relaxation and ferrimagnetic resonance in single domain samples of impure YIG; nuclear relaxation in the Bloch walls of insulators. The results of our calculations are generally in good agreement with experiment. (author) [French] On se propose d'interpreter les resultats d'experiences de resonance magnetique nucleaire fates par divers auteurs sur des composes ferro et ferrimagnetiques du groupe du fer. Les problemes abordes sont les suivants: effets des champs dipolaires et de l'anisotropie de structure hyperfine; intensite des signaux; deplacement de frequence du a l'interaction de Suhl-Nakamura entre spins nucleaires; relaxation nucleaire et resonance ferrimagnetique dans les echantillons monodomaines de grenat de fer et d'yttrium impur; relaxation nucleaire dans les parois de Bloch des isolants. Les resultats des calculs sont generalement en bon accord avec l'experience. (auteur)

Contribution to the study of nuclear resonance in magnetic media (1963); Contribution a l'etude de la resonance nucleaire dans les milieux magnetique (1963)

Energy Technology Data Exchange (ETDEWEB)

Hartmann-Boutron, F. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1963-06-15

An attempt is made to interpret the results of nuclear magnetic resonance experiments made by various workers on ferro and ferrimagnetic compounds of the iron group. The problems encountered are the following: effects of the dipolar fields and the hyperfine structure anisotropy; signal intensity; frequency pulling due to the Suhl-Nakamura interaction between nuclear spins ; nuclear relaxation and ferrimagnetic resonance in single domain samples of impure YIG; nuclear relaxation in the Bloch walls of insulators. The results of our calculations are generally in good agreement with experiment. (author) [French] On se propose d'interpreter les resultats d'experiences de resonance magnetique nucleaire fates par divers auteurs sur des composes ferro et ferrimagnetiques du groupe du fer. Les problemes abordes sont les suivants: effets des champs dipolaires et de l'anisotropie de structure hyperfine; intensite des signaux; deplacement de frequence du a l'interaction de Suhl-Nakamura entre spins nucleaires; relaxation nucleaire et resonance ferrimagnetique dans les echantillons monodomaines de grenat de fer et d'yttrium impur; relaxation nucleaire dans les parois de Bloch des isolants. Les resultats des calculs sont generalement en bon accord avec l'experience. (auteur)

Relationship between the nuclear resonance of cobalt metal and its ferromagnetic properties; Relations entre la resonance nucleaire du cobalt metallique et ses proprietes ferromagnetiques

Energy Technology Data Exchange (ETDEWEB)

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

1964-05-15

resulte du couplage intense existant entre les noyaux et les electrons porteurs du magnetisme. Ces derniers excitent les noyaux et, dans les parois de Bloch, les soumettent a un champ radio-frequence bien plus intense que le champ RF applique. Les parametres de la resonance se determinent alors a partir du mouvement des parois, et dependent donc des constantes ferromagnetiques. La theorie permet de prevoir quantitativement certains effets particuliers, notamment par action d'un champ magnetique continu ou de la temperature. L'etude expeimentale a porte sur des poudres de cobalt et est en bon accord avec la theorie. Toutefois il faut tenir compte de l'effet de peau et reviser la theorie en consequence. Ceci permet d'expliquer certaines divergences observees, ainsi que l'influence de la taille des grains et celle du champ magnetique sur la forme de raie. Des renseignements originaux ont ete obtenus sur certaines proprietes purement ferromagnetiques du cobalt, en etudiant l'effet d'un champ magnetique et cette methode a pu etre appliquee a d'autres corps ferromagnetiques. En raison du caractere particulier de cette resonance nucleaire, qui se produit en l'absence de champ directeur et possede une importante largeur de raie, des spectrographes de type nouveau ont ete realises qui ont rendu possible des mesures precises de la forme de raie. La faible intensite des signaux obtenus dans certains cas a conduit a la mise au point d'une methode originale d'extraction dont la theorie et les applications pratiques sont donnees ici. L'ensemble de ces experiences fait apparaitre la resonance nucleaire comme un puissant moyen d'etude du ferromagnetique permettant de deceler des phenomenes microscopiques difficilement accessibles par les methodes classiques. (auteur)

Relationship between the nuclear resonance of cobalt metal and its ferromagnetic properties; Relations entre la resonance nucleaire du cobalt metallique et ses proprietes ferromagnetiques

Energy Technology Data Exchange (ETDEWEB)

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

1964-05-15

Theoretical study of nuclear magnetic resonance in ferromagnetic metals shows the near dependence of ferromagnetic properties and unusual feature of this nuclear resonance. This results from a strong interaction between nuclei and magnetic electrons. They excite the nuclei, and, in Bloch walls, submit them to a RF field much stronger than those directly applied. The parameters of the resonance are determined from wall movement and depend consequently of ferromagnetic constants. The theory is enable to provide quantitatively some peculiar effects, specially those of a continuous magnetic field and of temperature. Experimental study was made on cobalt powders, and is in good agreement with theory. However one must take the skin-effect into consideration and accordingly adjust, the theory. This can explain some observed divergences, as well as the influence at particles size and magnetic field over the line shape. Original informations have been obtained about some typical ferromagnetic properties of cobalt, when studying magnetic field effect, and it has been able to apply this method to other ferromagnetic materials. In consideration of the peculiar characteristics of this nuclear resonance, which occurs without external magnetic field and whose line width is large, new models of spectrographs have been realized and have permitted accurate measures of the line shape. The weak intensity of the signals obtained in some cases, has induced the elaboration of an original method of extraction whose theory and practical uses are described here. The whole of this experiment reveals the nuclear resonance as a strong way for the study of ferromagnetism, which is able to detect microscopic phenomenons, not easily accessible by classical methods. (author) [French] L'etude theorique de la resonance magnetique nucleaire dans les metaux ferromagnetiques revele l'etroite liaison entre les proprietes ferromagnetiques et l'aspect inhabituel de cette resonance. Ceci resulte du

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

Energy Technology Data Exchange (ETDEWEB)

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)

129 Xe-NMR of carbon black filled elastomers

International Nuclear Information System (INIS)

Sperling-Ischinsky, K.; Veeman, W.S.

1999-01-01

It is shown that 129 Xe-NMR is a powerful tool to investigate carbon black and carbon black filled elastomers. For the carbon black material itself the 129 Xe chemical shift of xenon adsorbed at the surface of carbon black aggregates yields information about the relative average pore size of the carbon black aggregates. The experimental 129 Xe-NMR results of carbon black filled ethylene-propylene-diene (EPDM) can be explained when it is assumed that the xenon atoms in the bound EPDM fraction exchange rapidly on the NMR time scale between a state where they are adsorbed on the carbon black surface and a state in which they are absorbed in the EPDM layer. This would imply that the carbon black aggregates are not completely covered with EPDM chains. (author)

NMR investigations of surfaces and interfaces using spin-polarized xenon

International Nuclear Information System (INIS)

Gaede, H.C.; Lawrence Berkeley Lab., CA

1995-07-01

129 Xe NMR is potentially useful for the investigation of material surfaces, but has been limited to high surface area samples in which sufficient xenon can be loaded to achieve acceptable signal to noise ratios. In Chapter 2 conventional 129 Xe NMR is used to study a high surface area polymer, a catalyst, and a confined liquid crystal to determine the topology of these systems. Further information about the spatial proximity of different sites of the catalyst and liquid crystal systems is determined through two dimensional exchange NMR in Chapter 3. Lower surface area systems may be investigated with spin-polarized xenon, which may be achieved through optical pumping and spin exchange. Optically polarized xenon can be up to 10 5 times more sensitive than thermally polarized xenon. In Chapter 4 highly polarized xenon is used to examine the surface of poly(acrylonitrile) and the formation of xenon clathrate hydrates. An attractive use of polarized xenon is as a magnetization source in cross polarization experiments. Cross polarization from adsorbed polarized xenon may allow detection of surface nuclei with drastic enhancements. A non-selective low field thermal mixing technique is used to enhance the 13 C signal of CO 2 of xenon occluded in solid CO 2 by a factor of 200. High-field cross polarization from xenon to proton on the surface of high surface area polymers has enabled signal enhancements of ∼1,000. These studies, together with investigations of the efficiency of the cross polarization process from polarized xenon, are discussed in Chapter 5. Another use of polarized xenon is as an imaging contrast agent in systems that are not compatible with traditional contrast agents. The resolution attainable with this method is determined through images of structured phantoms in Chapter 6

Mechanics and electronics as auxiliary techniques in nuclear research and exploitation; Mecanique et electronique auxiliaires de la recherche et de l'exploitation nucleaire

Energy Technology Data Exchange (ETDEWEB)

Weill, J. [Commissariat a l' energie atomique et aux energies alternatives - CEA, Centre d' Etudes nucleaires de Saclay, Departement Electronique, Groupe Controle des Reacteurs (France)

1959-07-01

Electronics and mechanics form the basic techniques used in the field of measurement and control in nuclear physics experiments, and in nuclear machine installations. The delegate describes some instruments typical of the use of these techniques in the fields of calculation, detection, amplification and nuclear Installations. Reprint of a paper published in 'Bulletin S.F.M.' n. 25 (3. quarter 1957) [French] L'electronique et la mecanique constituent les techniques de base utilisees clans le domaine des mesures et du controle effectues dans les experiences de physique nucleaire et dans les installations des engins nucleaires. Le Conferencier decrit plusieurs appareils caracteristiques de l'emploi de ces techniques dans les domaines du calcul, des detecteurs, de l'amplification et des lnstallations nucleaires. Reproduction d'un article publie dans le 'Bulletin S.F.M.' n. 25 (3e trimestre 1957)

Nuclear spin-spin coupling in a van der Waals-bonded system: xenon dimer.

Science.gov (United States)

Vaara, Juha; Hanni, Matti; Jokisaari, Jukka

2013-03-14

Nuclear spin-spin coupling over van der Waals bond has recently been observed via the frequency shift of solute protons in a solution containing optically hyperpolarized (129)Xe nuclei. We carry out a first-principles computational study of the prototypic van der Waals-bonded xenon dimer, where the spin-spin coupling between two magnetically non-equivalent isotopes, J((129)Xe - (131)Xe), is observable. We use relativistic theory at the four-component Dirac-Hartree-Fock and Dirac-density-functional theory levels using novel completeness-optimized Gaussian basis sets and choosing the functional based on a comparison with correlated ab initio methods at the nonrelativistic level. J-coupling curves are provided at different levels of theory as functions of the internuclear distance in the xenon dimer, demonstrating cross-coupling effects between relativity and electron correlation for this property. Calculations on small Xe clusters are used to estimate the importance of many-atom effects on J((129)Xe - (131)Xe). Possibilities of observing J((129)Xe - (131)Xe) in liquid xenon are critically examined, based on molecular dynamics simulation. A simplistic spherical model is set up for the xenon dimer confined in a cavity, such as in microporous materials. It is shown that the on the average shorter internuclear distance enforced by the confinement increases the magnitude of the coupling as compared to the bulk liquid case, rendering J((129)Xe - (131)Xe) in a cavity a feasible target for experimental investigation.

Xenon Fractionation and Archean Hydrogen Escape

Science.gov (United States)

Zahnle, K. J.

2015-01-01

Xenon is the heaviest gas found in significant quantities in natural planetary atmospheres. It would seem the least likely to escape. Yet there is more evidence for xenon escape from Earth than for any element other than helium and perhaps neon. The most straightforward evidence is that most of the radiogenic Xe from the decay of (129)I (half-life 15.7 Myr) and (244)Pu (half-life 81 Myr) that is Earth's birthright is missing. The missing xenon is often attributed to the impact erosion of early atmospheres of Earth and its ancestors. It is obvious that if most of the radiogenic xenon were driven off by impacts, most of the rest of the atmophiles fared the same fate. The other line of evidence is in the nonradiogenic isotopes of xenon and its silent partner, krypton. Atmospheric xenon is strongly mass fractionated (at about 4% per amu) compared to any known solar system source (Figure 1). This is in stark contrast to krypton, which may not be fractionated at all: atmospheric Kr is slightly heavier than solar Kr (at about 0.5% per amu), but it is the same as in carbonaceous chondrites. Nonradiogenic xenon is also under abundant relative to krypton (the so-called "missing xenon" problem). Together these observations imply that xenon has been subject to fractionating escape and krypton not.

Nuclear magnetic resonance of iron-57 nuclei in local fields in yttrium and iron garnets; Resonance magnetique nucleaire des noyaux du fer 57 dans les champs locaux du grenat d'yttrium et de fer

Energy Technology Data Exchange (ETDEWEB)

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

1961-07-01

We have demonstrated the nuclear resonance of {sup 57}Fe nuclei in the local field of each of the two magnetic sub-lattices of yttrium and iron garnets. The resonance frequencies and the relaxation times have been measured as a function of the temperature. (author) [French] Nous avons mis en evidence la resonance nucleaire des noyaux de {sup 57}Fe dans le champ local de chacun des deux sous-reseaux magnetiques du grenat d'yttrium et de fer. Les frequences de resonances et les temps de relaxation ont ete mesures en fonction de la temperature. (auteur)

Iodine-129 in thyroids and tellurium isotopes in meteorites by neutron activation analysis

International Nuclear Information System (INIS)

Ballad, R.V.

1978-06-01

A combination of neutron activation and mass spectrometry has been used to determine the concentration of fissiogenic 129 I and the value of the 129 I/ 127 I ratio in thyroids of man, cow, and deer from Missouri. Deer thyroids show an average value of 129 I/ 127 I = 1.8 x 10 -8 and an average concentration of 3 x 10 -3 pCi 129 I per gram of thyroid (wet weight). Thyroids of cows and humans show successively lower values for the 129 I/ 127 I ratio and the 129 I content because their diets dilute fission-produced 129 I in the natural iodine cycle with mineral iodine. The results of analyses on a few thyroids from other geographic areas are also reported. The isotopic compositions of tellurium, krypton, and xenon were determined in acid-resistant residues of the Allende meteorite. Neutron activation and γ-counting were used to determine the relative abundances of six tellurium isotopes, and mass spectrometry was used to determine the isotopic compositions of krypton and xenon in aliquots of the same residues. Nucleogenetic anomalies were observed in the isotopic compositions of these three elements. The presence of isotopically distinct components of tellurium, krypton, and xenon in these residues provides strong support for the suggestion that our solar system formed directly from the debris of a supernova

¹²⁹ Xe NMR Relaxation-Based Macromolecular Sensing

Energy Technology Data Exchange (ETDEWEB)

Gomes, Muller D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Dao, Phuong [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Jeong, Keunhong [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Slack, Clancy C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Vassiliou, Christophoros C. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Finbloom, Joel A. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Francis, Matthew B. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Wemmer, David E. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Physical Biosciences Division; Pines, Alexander [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Univ. of California, Berkeley, CA (United States). Dept. of Chemistry

2016-07-29

A ¹²⁹Xe NMR relaxation-based sensing approach is reported on that exploits changes in the bulk xenon relaxation rate induced by slowed tumbling of a cryptophane-based sensor upon target binding. The amplification afforded by detection of the bulk dissolved xenon allows sensitive detection of targets. The sensor comprises a xenon-binding cryptophane cage, a target interaction element, and a metal chelating agent. Xenon associated with the target-bound cryptophane cage is rapidly relaxed and then detected after exchange with the bulk. Here we show that large macromolecular targets increase the rotational correlation time of xenon, increasing its relaxation rate. Upon binding of a biotin-containing sensor to avidin at 1.5 μM concentration, the free xenon T₂ is reduced by a factor of 4.

Optimization of Xenon Biosensors for Detection of Protein Interactions

International Nuclear Information System (INIS)

Lowery, Thomas J.; Garcia, Sandra; Chavez, Lana; Ruiz, E.Janette; Wu, Tom; Brotin, Thierry; Dutasta, Jean-Pierre; King, David S.; Schultz, Peter G.; Pines, Alex; Wemmer, David E.

2005-08-01

Hyperpolarized 129Xe NMR can detect the presence of specific low-concentration biomolecular analytes by means of the xenon biosensor, which consists of a water-soluble, targeted cryptophane-A cage that encapsulates xenon. In this work we use the prototypical biotinylated xenon biosensor to determine the relationship between the molecular composition of the xenon biosensor and the characteristics of protein-bound resonances. The effects of diastereomer overlap, dipole-dipole coupling, chemical shift anisotropy, xenon exchange, and biosensor conformational exchange on protein-bound biosensor signal were assessed. It was found that optimal protein-bound biosensor signal can be obtained by minimizing the number of biosensor diastereomers and using a flexible linker of appropriate length. Both the linewidth and sensitivity of chemical shift to protein binding of the xenon biosensor were found to be inversely proportional to linker length

Optical pumping and xenon NMR

International Nuclear Information System (INIS)

Raftery, M.D.

1991-11-01

Nuclear Magnetic Resonance (NMR) spectroscopy of xenon has become an important tool for investigating a wide variety of materials, especially those with high surface area. The sensitivity of its chemical shift to environment, and its chemical inertness and adsorption properties make xenon a particularly useful NMR probe. This work discusses the application of optical pumping to enhance the sensitivity of xenon NMR experiments, thereby allowing them to be used in the study of systems with lower surface area. A novel method of optically-pumping 129 Xe in low magnetic field below an NMR spectrometer and subsequent transfer of the gas to high magnetic field is described. NMR studies of the highly polarized gas adsorbed onto powdered samples with low to moderate surface areas are now possible. For instance, NMR studies of optically-pumped xenon adsorbed onto polyacrylic acid show that xenon has a large interaction with the surface. By modeling the low temperature data in terms of a sticking probability and the gas phase xenon-xenon interaction, the diffusion coefficient for xenon at the surface of the polymer is determined. The sensitivity enhancement afforded by optical pumping also allows the NMR observation of xenon thin films frozen onto the inner surfaces of different sample cells. The geometry of the thin films results in interesting line shapes that are due to the bulk magnetic susceptibility of xenon. Experiments are also described that combine optical pumping with optical detection for high sensitivity in low magnetic field to observe the quadrupoler evolution of 131 Xe spins at the surface of the pumping cells. In cells with macroscopic asymmetry, a residual quadrupolar interaction causes a splitting in the 131 Xe NMR frequencies in bare Pyrex glass cells and cells with added hydrogen

Economic consequences of the Swiss 'Sortir du nucleaire' and 'Moratoire-plus' popular initiatives - Analysis using a balanced model

International Nuclear Information System (INIS)

Mueller, A.; Wickart, M.; Van Nieuwkoop, R.

2001-01-01

This article is a short version of the ENET number 210359. This report for the Swiss Federal Office of Energy (SFOE) presents the results of a study made to assess the economic consequences of two models for the opting out of nuclear energy in Switzerland, as proposed in two popular initiatives. The 'Sortir du nucleaire' (electricity without atomic power) initiative calls for the shutting down of the existing nuclear power stations and the 'Moratoire-plus' initiative calls for a stop on the building of new atomic power stations for 10 years. The method used for assessing the costs and benefits resulting if the initiatives were accepted in a public vote is described. Basic assumptions made on further factors concerning the electricity and energy markets are discussed. Results of analyses made for various scenarios with respect to CO 2 emissions are presented and include discussions on risk costs, effects on employment and welfare aspects

Developpement d'une methode de Monte Carlo dependante du temps et application au reacteur de type CANDU-6

Science.gov (United States)

Mahjoub, Mehdi

La resolution de l'equation de Boltzmann demeure une etape importante dans la prediction du comportement d'un reacteur nucleaire. Malheureusement, la resolution de cette equation presente toujours un defi pour une geometrie complexe (reacteur) tout comme pour une geometrie simple (cellule). Ainsi, pour predire le comportement d'un reacteur nucleaire,un schema de calcul a deux etapes est necessaire. La premiere etape consiste a obtenir les parametres nucleaires d'une cellule du reacteur apres une etape d'homogeneisation et condensation. La deuxieme etape consiste en un calcul de diffusion pour tout le reacteur en utilisant les resultats de la premiere etape tout en simplifiant la geometrie du reacteur a un ensemble de cellules homogenes le tout entoure de reflecteur. Lors des transitoires (accident), ces deux etapes sont insuffisantes pour pouvoir predire le comportement du reacteur. Comme la resolution de l'equation de Boltzmann dans sa forme dependante du temps presente toujours un defi de taille pour tous types de geometries,un autre schema de calcul est necessaire. Afin de contourner cette difficulte, l'hypothese adiabatique est utilisee. Elle se concretise en un schema de calcul a quatre etapes. La premiere et deuxieme etapes demeurent les memes pour des conditions nominales du reacteur. La troisieme etape se resume a obtenir les nouvelles proprietes nucleaires de la cellule a la suite de la perturbation pour les utiliser, au niveau de la quatrieme etape, dans un nouveau calcul de reacteur et obtenir l'effet de la perturbation sur le reacteur. Ce projet vise a verifier cette hypothese. Ainsi, un nouveau schema de calcul a ete defini. La premiere etape de ce projet a ete de creer un nouveau logiciel capable de resoudre l'equation de Boltzmann dependante du temps par la methode stochastique Monte Carlo dans le but d'obtenir des sections efficaces qui evoluent dans le temps. Ce code a ete utilise pour simuler un accident LOCA dans un reacteur nucleaire de type

Contribution to the study of several chemical hazards in the Centre d'Etudes Nucleaires of Fontenay-aux-Roses; Contribution a l'etude de quelques nuisances chimiques au centre d'etudes nucleaires de Fontenay-aux-Roses

Energy Technology Data Exchange (ETDEWEB)

Megemont, C; Grau, C [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1968-10-01

From the checking of 2750 index cards of hazards, the study relates the distribution of the chemical hazards in the Centre d'Etudes Nucleaires of Fontenay-aux-Roses. Those concerning the greatest number of agents in the Centre are classified according to the categories corresponding to the different conditions of working. Thus, the most important are put forward. Then, the authors rapidly make a review of hazards which may have some special interest because they appear more specific of the nuclear energy or because they are the most frequently noted on the index cards of hazards. The case of the tributylphosphate is studied more precisely. (authors) [French] A partir de l'examen de 2750 fiches de nuisances, l'etude porte sur la repartition des nuisances chimiques au Centre d'Etudes Nucleaires de Fontenay-aux-Roses. Celles qui concernent le plus grand nombre d'agents du Centre sont classees selon les categories correspondant aux differentes conditions de travail. Les plus importantes d'entre elles sont ainsi mises en evidence. | Les auteurs passent ensuite en revue, rapidement, les nuisances qui peuvent presenter un interet particulier soit parce qu'elles semblent plus specifiques de l'Energie Nucleaire, soit parce qu'on les rencontre le plus frequemment sur les fiches de nuisances. Le cas du tributylphosphate est envisage de facon plus detaillee. (auteurs)

Imaging Human Brain Perfusion with Inhaled Hyperpolarized 129Xe MR Imaging.

Science.gov (United States)

Rao, Madhwesha R; Stewart, Neil J; Griffiths, Paul D; Norquay, Graham; Wild, Jim M

2018-02-01

Purpose To evaluate the feasibility of directly imaging perfusion of human brain tissue by using magnetic resonance (MR) imaging with inhaled hyperpolarized xenon 129 ( 129 Xe). Materials and Methods In vivo imaging with 129 Xe was performed in three healthy participants. The combination of a high-yield spin-exchange optical pumping 129 Xe polarizer, custom-built radiofrequency coils, and an optimized gradient-echo MR imaging protocol was used to achieve signal sensitivity sufficient to directly image hyperpolarized 129 Xe dissolved in the human brain. Conventional T1-weighted proton (hydrogen 1 [ 1 H]) images and perfusion images by using arterial spin labeling were obtained for comparison. Results Images of 129 Xe uptake were obtained with a signal-to-noise ratio of 31 ± 9 and demonstrated structural similarities to the gray matter distribution on conventional T1-weighted 1 H images and to perfusion images from arterial spin labeling. Conclusion Hyperpolarized 129 Xe MR imaging is an injection-free means of imaging the perfusion of cerebral tissue. The proposed method images the uptake of inhaled xenon gas to the extravascular brain tissue compartment across the intact blood-brain barrier. This level of sensitivity is not readily available with contemporary MR imaging methods. © RSNA, 2017.

Validating excised rodent lungs for functional hyperpolarized xenon-129 MRI.

Directory of Open Access Journals (Sweden)

David M L Lilburn

Full Text Available Ex vivo rodent lung models are explored for physiological measurements of respiratory function with hyperpolarized (hp (129Xe MRI. It is shown that excised lung models allow for simplification of the technical challenges involved and provide valuable physiological insights that are not feasible using in vivo MRI protocols. A custom designed breathing apparatus enables MR images of gas distribution on increasing ventilation volumes of actively inhaled hp (129Xe. Straightforward hp (129Xe MRI protocols provide residual lung volume (RV data and permit for spatially resolved tracking of small hp (129Xe probe volumes during the inhalation cycle. Hp (129Xe MRI of lung function in the excised organ demonstrates the persistence of post mortem airway responsiveness to intravenous methacholine challenges. The presented methodology enables physiology of lung function in health and disease without additional regulatory approval requirements and reduces the technical and logistical challenges with hp gas MRI experiments. The post mortem lung functional data can augment histological measurements and should be of interest for drug development studies.

Statistical pulses generator. Application to nuclear instrumentation (1962); Generateur d'impulsions aleatoires. Application a l'instrumentation nucleaire (1962)

Energy Technology Data Exchange (ETDEWEB)

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

1962-07-01

This report describes a random pulses generator adapted to nuclear instrumentation. After a short survey on the statistical nature of electronic signals, the different ways for generating pulses with a Poisson's time-distribution are studied. The final generator built from a gaseous thyratron in a magnetic field is then described. Several tests are indicated : counting-rate stability, Pearson's criterion, distribution of time-intervals. Applications of the generator in 'whole testing' of nuclear instrumentation are then indicated for sealers, dead time measurements, time analyzers. In this application, pulse-height spectrums have been made by Poissonian sampling of a recurrent or random low-frequency signal. (author) [French] Cette etude decrit un generateur d'impulsions aleatoires et ses applications a l'instrumentation nucleaire. Apres un bref rappel sur la nature statistique des signaux en electronique nucleaire, sont passes en revue les principaux moyens d'obtenir des impulsions distribuees en temps suivant une loi de Poisson. Le generateur utilisant un thyratron a gaz dans un champ magnetique est ensuite decrit; diverses methodes de test sont appliquees (stabilite du taux de comptage, criterium de Pearson, spectre des intervalles ds temps). Les applications du generateur a l'electronique nucleaire dans le domaine des 'essais globaux' sont indiques: test des echelles de comptage et mesure des temps morts, test des analyseurs en temps apres division du taux de comptage par une puissance de deux, test des analyseurs multicanaux en amplitude. Pour cette derniere application, on a realise des spectres d'amplitudes suivant une loi connue, par echantillonnage poissonien d'un signal basse frequence recurrent ou aleatoire. (auteur)

The influence of xenon poisoning in high-flux reactors on the choice of control rod speeds (1961); Influence de l'empoisonnement xenon dans les piles a haut flux sur le choix de la vitesse des barres de controle (1961)

Energy Technology Data Exchange (ETDEWEB)

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

1961-07-01

- The general laws are restated concerning the changes in xenon and iodine concentrations in thermal neutron reactors, assuming an uniform neutron flux distribution in the core. It is shown how the evolution in the xenon poisoning influences the selection of the control rod speed, at start-up. Certain simple methods of calculation are developed making it possible to resolve the problem of the choice of this speed in the case where the xenon poisoning is taken into account. (author) [French] - On rappelle les lois generales relatives aux evolutions de concentration xenon et iode dans les piles atomiques a neutrons thermiques lorsqu'on suppose une repartition uniforme du flux de neutrons dans le coeur. On montre comment l'evolution de l'empoisonnement xenon influe sur le choix de la vitesse des barres de controle en periode de demarrage. On developpe certaines methodes de calculs simples permettant de resoudre le probleme du choix de la vitesse des barres de controle, dans le cas ou l'on tient compte de l'empoisonnement xenon. (auteur)

The pulsed neutron method applied to the determination of the nuclear constants of graphite (1961); La methode des neutrons pulses appliquee a la determination des constantes nucleaires du graphite (1961)

Energy Technology Data Exchange (ETDEWEB)

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

1961-07-01

A method for determining the nuclear constants {sigma}{sub a} and {lambda}{sub t} of a moderator is described. The disappearance of a burst of neutrons introduced into a finite medium is studied as a function of time. This decrease in the thermal neutron density is the product of two exponentials; one representing the absorption, the other the leakage. By varying one or other of these factors, the constants of the factor left unvaried can be determined, and from this the nuclear constant values are deduced. (author) [French] On decrit une methode permettant de determiner les constantes nucleaires {sigma}{sub a} et {lambda}{sub t} d'un moderateur. On etudie la decroissance dans le temps d'une bouffee de neutrons introduite dans un milieu fini. Cette decroissance de la densite en neutrons thermiques est le produit de deux exponentielles; l'une represente l'absorption, l'autre les fuites. Par variation de l'un ou l'autre de ces facteurs, on determine les constantes du facteur laisse invariant dont on deduit les valeurs des constantes nucleaires. (auteur)

Specific activity of 129I in environmental samples

International Nuclear Information System (INIS)

Ravi, P.M.; Iyer, M.R.; Bhat, I.S.; Somasundaram, S.; Subramanian, M.S.

1988-01-01

129 I finds its way into the environment as a result of man-made nuclear operations. It is also formed by the interaction of cosmic rays with xenon isotopes and spontaneous fission of naturally occurring uranium. 129 I and stable 127 I contents of thyroid, milk, seaweed and aplysia cell samples collected from around a fuel reprocessing plant were estimated by neutron activation analysis method. The annual 129 I intake of an individual works out to be about 0.3 Bq as compared to the natural radioactivity content in human body of about 5000 Bq. (author). 3 tabs

Terrestrial xenon isotope constraints on the early history of the earth

International Nuclear Information System (INIS)

Ozima, M.; Igarashi, G.; Podosek, F.A.

1985-01-01

Comparison between 129 I-radiogenic 129 Xe and 244 Pu-fissiogenic 136 Xe components in terrestrial xenon suggests that the Earth's inner region accreted a few tens of millions of years earlier than the outer region from which the atmosphere evolved. The results also indicate that there has been no substantial mixing of the two regions since the Earth's accretion. (author)

A sensitive zinc-activated 129Xe MRI probe

International Nuclear Information System (INIS)

Kotera, N.; Delacour, L.; Traore, T.; Buisson, D.A.; Taran, F.; Coudert, S.; Rousseau, B.; Tassali, N.; Leonce, E.; Boutin, C.; Berthault, P.; Brotin, T.; Dutasta, J.P.

2012-01-01

Herein we propose the use of hyper-polarized 129 Xe nuclear magnetic resonance (NMR) spectroscopy for the sensitive detection of Zn 2+ ions. To achieve this goal, the noble gas is encapsulated in dedicated host systems bearing a ligand that chelates the Zn 2+ ions. Cryptophanes, aromatic cage molecules made of cyclotriveratrylene groups, are perfectly suited to this purpose as 1) they can easily be rendered water-soluble, 2) the noble gas has a high affinity for their cavity, 3) when xenon is encapsulated, it takes a specific NMR frequency, and 4) xenon exchange in and out of the cavity insures a continuous refreshment of the Xe-cryptophane environment in hyper-polarization. We constructed a powerful 129 Xe NMR-based sensor of Zn 2+ ions, which enables for the first time measurement of Zn 2+ concentrations as low as 100 nm. This high sensitivity was achieved thanks to a smart 129 Xe MRI sensor, where the binding of the ion to the target is accompanied by a change in NMR parameters. We have also demonstrated the importance of working with enantiopure cryptophane derivatives. (O.M.)

The nuclear power stations of the French atomic energy programme (1960); Les centrales nucleaires de puissance du programme francais (1960)

Energy Technology Data Exchange (ETDEWEB)

Leduc, C [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires; Roux, J P [Electricite de France (EDF), 75 - Paris (France)

1960-07-01

After recalling the entry of nuclear energy into energy production in France, the paper emphasizes the evolution of techniques applied in the designing of French nuclear power plants and describes the means employed for reducing costs per kWh of EDF2 and EDF3 compared with EDF1: the electric power per ton of uranium varies from 493 kW/t for EDF1 to 970 kW/t for EDF3. For this purpose the thermal power and electric power of units are changed respectively from 290 MWt for EDF1 to 1200 or 1600 MWt for EDF3 and from 28 to 250 MW. The results are obtained by an improvement in neutronic characteristics, developments in nuclear fuel technology, and simplification of the system of charging the reactor, whose means of maintenance are increased; the EDF2 heat-exchangers have been so designed as to increase the unit power of the elements, which will attain 9 MWt, as against 3 for EDF1. For EDF3 an advance project forecasts a thermodynamic layout with only one pressure stage. The paper ends with a description of the burst-slug detection systems, and an appendix gives a detailed comparative table of EDF1, EDF2 and EDF3 plant characteristics. (author) [French] Apres avoir rappele l'integration de l'energie nucleaire parmi les moyens de production de l'energie en France, les auteurs se penchent surtout sur l'evolution des techniques appliquees dans l'equipement des centrales nucleaires francaises et decrivent les moyens mis en oeuvre pour reduire les prix de revient du kWh d'EDF2 et d'EDF3 par rapport a EDF1: la puissance electrique par tonne d'uranium varie de 493 kW/t pour EDF1 a 970 kW/t pour EDF3. C'est dans ce but que les puissances thermiques et la puissance unitaire des groupes turbo-alternateurs passent respectivement de 290 MWt pour EDF1 a 1200 ou 1600 MWt pour EDF3 et de 82 a 250 MW. Les resultats sont obtenus par une amelioration des caracteristiques neutroniques, des progres realises sur la technologie des elements combustibles, une simplification du systeme de

Communication Received from the Permanent Mission of Brazil regarding Certain Member States' Guidelines for the Export of Nuclear Material, Equipment and Technology; Communication recue de la mission permanente du Bresil concernant les Directives de certains Etats Membres applicables a l'exportation de matieres, d'equipements et de technologie nucleaires

Energy Technology Data Exchange (ETDEWEB)

NONE

2007-12-03

The Agency has received a Note Verbale from the Permanent Mission of Brazil, dated 22 March 2007, in which it requests that the Agency circulate to all Member States a letter of 12 December 2006 from the Chairman of the Nuclear Suppliers Group, Ambassador Jose Artur Denot Medeiros, to the Director General, on behalf of the Governments of Argentina, Australia, Austria, Belarus, Belgium, Brazil, Bulgaria, Canada, China, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Japan, Kazakhstan, Republic of Korea, Latvia, Lithuania, Luxemburg, Malta, Netherlands, New Zealand, Norway, Poland, Portugal, Romania, Russian Federation, Slovakia, Slovenia, South Africa, Spain, Sweden, Switzerland, Turkey, Ukraine, the United Kingdom of Great Britain and Northern Ireland and the United States of America, providing further information on those Governments' Guidelines for Nuclear Transfers [French] L'Agence a recu une note verbale de la mission permanente du Bresil, en date du 22 mars 2007, lui demandant de diffuser a tous les Etats Membres une lettre du 12 decembre 2006 du president du Groupe des fournisseurs nucleaires, l'ambassadeur Artur Denot Medeiros, adressee au Directeur general au nom des gouvernements des Etats suivants : Afrique du Sud, Allemagne, Argentine, Australie, Autriche, Belarus, Belgique, Bresil, Bulgarie, Canada, Chine, Chypre, Croatie, Danemark, Espagne, Estonie, Etats-Unis d'Amerique, Federation de Russie, Finlande, France, Grece, Hongrie, Irlande, Italie, Japon, Kazakhstan, Lettonie, Lituanie, Luxembourg, Malte, Norvege, Nouvelle-Zelande, Pays-Bas, Pologne, Portugal, Republique de Coree, Republique tcheque, Roumanie, Royaume-Uni de Grande-Bretagne et d'Irlande du Nord, Slovaquie, Slovenie, Suede, Suisse, Turquie et Ukraine. Cette lettre apporte des informations supplementaires sur les Directives de ces gouvernements applicables aux transferts nucleaires.

NMR and MRI of continuously dissolved hyperpolarized {sup 129}Xe by means of hollow fibers

Energy Technology Data Exchange (ETDEWEB)

Amor, Nadia; Kueppers, Markus; Bluemich, Bernhard [ITMC of RWTH Aachen University (Germany); Hamilton, Kathrin; Schmitz-Rode, Thomas; Steinseifer, Ulrich [HIA of RWTH Aachen University (Germany); Appelt, Stephan [Research Center Juelich (Germany)

2011-07-01

Various methods of hyperpolarizing (HP) spin systems have been developed during the last years to increase the intrinsically low sensitivity of NMR by several orders of magnitude. Among them is the hyperpolarization of {sup 129}Xe via Spin Exchange Optical Pumping (SEOP). NMR of HP {sup 129}Xe is of great interest because of its good solubility and its very sensitive chemical shift. The main obstacle for many applications is the efficient and continuous dissolution into carrier agents without formation of foams or bubbles. It has been overcome by the so-called ''xenonizer'' setups. They mainly consist of commercially available hollow fiber membranes typically used in clinical oxygenators. A purpose-built xenonizer setup has been developed and analyzed in detail by NMR spectroscopy and MRI for varying fiber materials as well as for different fluids, including bio-relevant fluids such as blood, plasma, and erythrocytes. As a result, the xenonizer technology could be further understood and improved, and new applications of HP {sup 129}Xe for medical NMR were explored.

Study of xenon binding in cryptophane-A using laser-induced NMR polarization enhancement

International Nuclear Information System (INIS)

Luhmer, M.; Goodson, B.M.; Song, Y.Q.; Laws, D.D.; Kaiser, L.; Pines, A.; Lawrence Berkeley National Lab., CA

1999-01-01

Xenon is chemically inert, yet exhibits NMR parameters that are highly sensitive to its chemical environment. Considerable work has therefore capitalized on the utility of 129 Xe (I = 1/2) as a magnetic resonance probe of molecules, materials, and biological systems. In solution, spin-polarization transfer between laser-polarized xenon and the hydrogen nuclei of nearby molecules leads to signal enhancements in the resolved 1 H NMR spectrum, offering new opportunities for probing the chemical environment of xenon atoms. Following binding of laser-polarized xenon to molecules of cryptophane-A, selective enhancements of the 1 H NMR signals were observed. A theoretical framework for the interpretation of such experimental results is provided, and the spin polarization-induced nuclear Overhauser effects are shown to yield information about the molecular environment of xenon. The observed selective 1 H enhancements allowed xenon-proton internuclear distances to be estimated. These distances reveal structural characteristics of the complex, including the preferred molecular conformations adopted by cryptophane-A upon binding of xenon

Is it possible to recycle nuclear wastes? Costs, risks and stakes of the plutonium industry; Peut-on recycler les dechets nucleaires? Couts, risques et enjeux de l'industrie du plutonium

Energy Technology Data Exchange (ETDEWEB)

NONE

2009-07-01

This document, published by the French association 'Sortir du nucleaire' (Get out of nuclear), gives some information on the chain reaction from uranium to plutonium, the difference between reprocessing (which does not reduce waste volumes but multiply waste types) and recycling, the high risks associated with plutonium transport, La Hague as the most dangerous nuclear site in France, reprocessing as the alibi for the French nuclear industry, Areva as an expert in propaganda, reprocessing as an absurd world strategy, plutonium as a fuel for proliferation, the myth of unlimited energy with the breeder reactors, and so on

Improvement of spin-exchange optical pumping of xenon-129 using in situ NMR measurement in ultra-low magnetic field

Science.gov (United States)

Takeda, Shun; Kumagai, Hiroshi

2018-02-01

Hyperpolarized (HP) noble gas has attracted attention in NMR / MRI. In an ultra-low magnetic field, the effectiveness of signal enhancement by HP noble gas should be required because reduction of the signal intensity is serious. One method of generating HP noble gas is spin exchange optical pumping which uses selective excitation of electrons of alkali metal vapor and spin transfer to nuclear spin by collision to noble gas. Although SEOP does not require extreme cooling or strong magnetic field, generally it required large-scale equipment including high power light source to generate HP noble gas with high efficiency. In this study, we construct a simply generation system of HP xenon-129 by SEOP with an ultralow magnetic field (up to 1 mT) and small-scale light source (about 1W). In addition, we measure in situ NMR signal at the same time, and then examine efficient conditions for SEOP in ultra-low magnetic fields.

Production and delivery of polarized Xenon-129 for in vivo MRS/MRI.

Science.gov (United States)

Rosen, Matthew S.; Chupp, Timothy E.; Coulter, Kevin P.; Welsh, Robert C.; Swanson, Scott

1998-05-01

Laser polarized ^129Xe can be used as an entirely new magnetic tracer, and is a powerful enhancement to currently existing MRI techniques. Inert laser polarized ^129Xe is inhaled and transported via blood flow where it is detected using MR spectroscopy and imaging techniques. The time-dependent distribution patterns of ^129Xe signal intensity directly reflect local blood volume, blood flow rates, and the efficiency of perfusion and diffusive transport in tissues. We have developed a uniquely constructed laser polarized ^129Xe production and delivery system that is used in both our in vitro and in vivo imaging experiments with rats. This reliable, effective, and relatively simple production method for large volumes of laser polarized ^129Xe is the key to all other areas of research involving use of laser polarized gases.

Krypton purification (1961); Purification du krypton (1961)

Energy Technology Data Exchange (ETDEWEB)

Larher, Y [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Institut Fourier, 38 - Grenoble (France)

1961-07-01

The amount of xenon in otherwise very pure krypton can be reduced from 1.5 to 0.0025 per cent approximately by passage through an activated carbon column at dry-ice temperature. The circulation of the krypton is effected by condensing at -196 deg. C and then evaporating. (author) [French] Le taux de xenon dans du krypton par ailleurs tres pur est ramene de 1,5 pour cent a 0,0025 pour cent environ au cours d'un passage a travers une colonne de charbon actif a la temperature de la carboglace. La circulation du krypton se fait par condensation a -196 deg. C, puis evaporation. (auteur)

Hyperpolarized 129Xe MRI: A viable functional lung imaging modality?

International Nuclear Information System (INIS)

Patz, Samuel; Hersman, F. William; Muradian, Iga; Hrovat, Mirko I.; Ruset, Iulian C.; Ketel, Stephen; Jacobson, Francine; Topulos, George P.; Hatabu, Hiroto; Butler, James P.

2007-01-01

The majority of researchers investigating hyperpolarized gas MRI as a candidate functional lung imaging modality have used 3 He as their imaging agent of choice rather than 129 Xe. This preference has been predominantly due to, 3 He providing stronger signals due to higher levels of polarization and higher gyromagnetic ratio, as well as its being easily available to more researchers due to availability of polarizers (USA) or ease of gas transport (Europe). Most researchers agree, however, that hyperpolarized 129 Xe will ultimately emerge as the imaging agent of choice due to its unlimited supply in nature and its falling cost. Our recent polarizer technology delivers vast improvements in hyperpolarized 129 Xe output. Using this polarizer, we have demonstrated the unique property of xenon to measure alveolar surface area noninvasively. In this article, we describe our human protocols and their safety, and our results for the measurement of the partial pressure of pulmonary oxygen (pO 2 ) by observation of 129 Xe signal decay. We note that the measurement of pO 2 by observation of 129 Xe signal decay is more complex than that for 3 He because of an additional signal loss mechanism due to interphase diffusion of 129 Xe from alveolar gas spaces to septal tissue. This results in measurements of an equivalent pO 2 that accounts for both traditional T 1 decay from pO 2 and that from interphase diffusion. We also provide an update on new technological advancements that form the foundation for an improved compact design polarizer as well as improvements that provide another order-of-magnitude scale-up in xenon polarizer output

129Xe nuclear magnetic resonance study of pitch-based activated carbon modified by air oxidation/pyrolysis cycles: a new approach to probe the micropore size.

Science.gov (United States)

Romanenko, Konstantin V; Py, Xavier; d'Espinose de Lacaillerie, Jean-Baptiste; Lapina, Olga B; Fraissard, Jacques

2006-02-23

(129)Xe NMR has been used to study a series of homologous activated carbons obtained from a KOH-activated pitch-based carbon molecular sieve modified by air oxidation/pyrolysis cycles. A clear correlation between the pore size of microporous carbons and the (129)Xe NMR of adsorbed xenon is proposed for the first time. The virial coefficient delta(Xe)(-)(Xe) arising from binary xenon collisions varied linearly with the micropore size and appeared to be a better probe of the microporosity than the chemical shift extrapolated to zero pressure. This correlation was explained by the fact that the xenon collision frequency increases with increasing micropore size. The chemical shift has been shown to vary very little with temperature (less than 9 ppm) for xenon trapped inside narrow and wide micropores. This is indicative of a smooth xenon-surface interaction potential.

Relaxation rates of low-field gas-phase ^129Xe storage cells

Science.gov (United States)

Limes, Mark; Saam, Brian

2010-10-01

A study of longitudinal nuclear relaxation rates T1 of ^129Xe and Xe-N2 mixtures in a magnetic field of 3.8 mT is presented. In this regime, intrinsic spin relaxation is dominated by the intramolecular spin-rotation interaction due to persistent xenon dimers, a mechanism that can be quelled by introducing large amounts of N2 into the storage cell. Extrinsic spin relaxation is dominated by the wall-relaxation rate, which is the primary quantity of interest for the various low-field storage cells and coatings that we have tested. Previous group work has shown that extremely long gas-phase relaxation times T1 can be obtained, but only at large magnetic fields and low xenon densities. The current work is motivated by the practical benefits of retaining hyperpolarized ^129Xe for extended periods of time in a small magnetic field.

Xenon-Xenon collision events in CMS

CERN Multimedia

Mc Cauley, Thomas

2017-01-01

One of the first-ever xenon-xenon collision events recorded by CMS during the LHC’s one-day-only heavy-ion run with xenon nuclei. The large number of tracks emerging from the centre of the detector show the many simultaneous nucleon-nucleon interactions that take place when two xenon nuclei, each with 54 protons and 75 neutrons, collide inside CMS.

Cluster formation restricts dynamic nuclear polarization of xenon in solid mixtures

DEFF Research Database (Denmark)

Kuzma, N. N.; Pourfathi, M.; Kara, H.

2012-01-01

During dynamic nuclear polarization (DNP) at 1.5 K and 5 T, Xe-129 nuclear magnetic resonance (NMR) spectra of a homogeneous xenon/1-propanol/trityl-radical solid mixture exhibit a single peak, broadened by H-1 neighbors. A second peak appears upon annealing for several hours at 125 K. Its...

Study of the chimney produced by an underground nuclear explosion; Etude de la cheminee creee par une explosion nucleaire souterraine

Energy Technology Data Exchange (ETDEWEB)

Derlich, S [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

1969-07-01

Underground nuclear explosions lead to the formation of a cavity which is roughly of spherical shape. The roof of this cavity is unstable and collapses in most cases, leading to the formation of a chimney. The height and the diameter depend on the energy of the charge and on the nature of the surroundings. The chronology of the various stages can be determined by seismic observations. The interior of the chimney is filled, either partially or completely, with rubble earth. This phenomenon is of great importance as far as the use of nuclear explosions for industrial applications is concerned. (author) [French] Les explosions nucleaires souterraines creent une cavite de forme grossierement spherique. La voute de cette cavite est instable et s'effondre dans la plupart des cas, donnant lieu a la formation d'une cheminee. La hauteur et le diametre sont fonction de l'energie du tir et de la nature du milieu. La chronologie des evenements peut etre determinee par des observations seismiques. L'interieur des cheminees est occupe, en partie ou en totalite, par des eboulis. Ce phenomene presente un grand interet pour l'utilisation des explosions nucleaires a des fins industrielles. (auteur)

'Clickable' hydrosoluble PEGylated cryptophane as a universal platform for 129Xe magnetic resonance imaging biosensors

International Nuclear Information System (INIS)

Delacour, Lea; Kotera, Naoko; Traore, Tenin; Garcia-Argote, Sebastien; Puente, Celine; Gravel, Edmond; Rousseau, Bernard; Leteurtre, Francois; Boulard, Yves; Tassali, Nawal; Boutin, Celine; Leonce, Estelle; Berthault, Patrick

2013-01-01

We describe the synthesis of a highly water-soluble cryptophane 1 that can be seen as a universal platform for the construction of 129 Xe magnetic resonance imaging (MRI)-based biosensors. Compound 1 is easily functionalized by Huisgen cycloaddition and exhibits excellent xenon-encapsulation properties. In addition, 1 is nontoxic at the concentrations typically used for hyper-polarized 129 Xe MRI. (authors)

Some aspects of the nuclear fission process; Quelques aspects du processus de fission nucleaire

Energy Technology Data Exchange (ETDEWEB)

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

1961-07-01

In the following report one can find first a short general view on the present situation of our knowledge concerning the nuclear fission process, namely on the nucleus going through the saddle-point. Then there are some aspects connected with the excitation energy of the fissioning nucleus. The measurements made at Saclay on the fast neutron fission cross-section of U{sup 233}, U{sup 235}, Pu{sup 239}, U{sup 238} are described at the beginning of this work. It appears that for U{sup 233} there is some characteristic shape modulation of the cross-section curve, in relation with the collective excited state of the deformed nucleus at the saddle-point. Good evidence of this is also given by the study of the relative fission rate with emission of long-range particles; it appears also that this ternary fission rate does not change substantially for neutron between thermal energy and 2 MeV, but that is very lower for the compound nucleus U{sup 239} than for even-even compound nuclei. At the end there are some experiments on the strong 4,5 MeV gamma-ray originated by slow neutron absorption in U{sup 235}. Time-of-flight device is used to establish that this 4,5 MeV gamma-ray seems mostly connected with radiative capture. (author) [French] Le present travail debute par un apercu de l'etat actuel de nos connaissances sur le processus de fission nucleaire, notamment sur le passage par le point-seuil. Puis sont evoques des aspects lies au niveau d'energie d'excitation auquel est porte le noyau qui subit la fission. Les mesures de sections efficaces de fission induite dans {sup 233}U, {sup 235}U, {sup 239}Pu et {sup 238}U par des neutrons rapides effectuees a Saclay sont decrites en premier lieu; elles font apparaitre pour {sup 233}U une ondulation caracteristique du role des etats collectifs d'excitation du noyau deforme au point-seuil. Des experiences sur la fission avec emission de particules de long parcours confirment cet aspect tout en demontrant que la frequence

Nuclear explosion and internal contamination; Explosion nucleaire et contamination interne

Energy Technology Data Exchange (ETDEWEB)

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

1956-07-01

By the study of the conditions of internal contamination due to the radioactive mixture produced by a nuclear explosion, the parts played by the relative weights of the different elements and the mode of expression of the doses are considered. Only the knowledge of the weight composition of the contamination mixture and of its evolution as a function of time can provide the required basis for the study of its metabolism in the organism. The curves which give the composition of the fission product mixture - in number of nuclei - - as a function of time - have been established. These curves are applied to some practical examples, particularly relative to the nature of contamination, radiotoxicity of some elements and assessment of hazards. (author) [French] Etudiant les modalites de la contamination interne par les elements radioactifs apparus lors d'une explosion nucleaire, le role de la 'masse' et le mode d'expression des doses sont envisages. La connaissance de la composition en 'masse' du melange contaminant et de son evolution en fonction du temps peut seule apporter les bases necessaires a l'etude de son comportement dans l'organisme. Les courbes donnant la composition du melange de produits de fission - en nombre de noyaux - - en fonction du temps - ont ete etablies. Quelques applications pratiques, relatives en particulier a la nature de la contamination, a la radiotoxicite de certains elements et a l'evaluation de risque, sont envisagees a titre d'exemple. (auteur)

Conception and synthesis of the new cryptophane for the applications in xenon NMR molecular imaging

International Nuclear Information System (INIS)

Gao, Bo

2016-01-01

Among all the imaging techniques, magnetic resonance imaging (MRI) offers several advantages owing to its low invasiveness, its harmlessness and its spatial in-depth resolution but suffers from poor sensitivity. To address this issue, different strategies were proposed, including the utilization of hyper-polarizable species such as "1"2"9Xe. Xenon is an inert gas with a polarizable electronic cloud which leads to an extreme sensitivity to its chemical environment. Its capacity of being hyper-polarized makes it possible to obtain a significant gain of sensitivity. Nevertheless, xenon has no specificity to any biological target therefore it needs to be encapsulated and vectorized. Different molecular cages were proposed and we are particularly interested in cryptophane which is one of the best candidates for xenon encapsulation. In this context, the objective of this thesis is to design new cryptophanes which can be used as molecular platforms to construct novel "1"2"9Xe MRI biosensors usable for in vivo imaging. To meet this demand, these cryptophanes should be mono-functionalizable and enough soluble in water. In this thesis, the polyethylene glycol (PEG) group is used to improve the poor solubility of the hydrophobic molecular cage. And there is a systematic discussion of how to break the symmetry of cryptophanes and different strategies were attempted to synthesize mono-functionalized cryptophanes. As a result, several PEGylated mono-functionalized cryptophanes were obtained and their properties for encapsulating xenon were tested [fr

Conception and synthesis of new molecular cages for xenon MRI applications

International Nuclear Information System (INIS)

Delacour, L.

2011-01-01

Non-invasive proton magnetic resonance imaging ( 1 H MRI) is a powerful clinical tool for the detection of numerous diseases. Although MRI contrast agents are often used to improve diagnostic specificity, this technique has limited applications in molecular imaging because of its inherently low sensitivity when compared to nuclear medicine or fluorescence imaging. Laser-polarized 129 Xe NMR spectroscopy is a promising tool to circumvent sensitivity limitations. Indeed, optical pumping increases the nuclear spin polarization of xenon by several orders of magnitude (10 4 to 10 5 ), thus small amounts of gas dissolved in biological tissues (blood, lungs...) can be rapidly detected with an excellent signal-to-noise ratio. In addition, the high polarizability of the xenon electron cloud, which induces a very high sensitivity to its environment, makes this nucleus very attractive for molecular imaging. Detection of biomolecules can be achieved by biosensors, which encapsulate xenon atoms in molecular cages that have been functionalized to bind the desired biological target. Cage molecules such as cryptophanes have high affinity for xenon and thus appear as ideal candidates for its encapsulation. During this PhD thesis we worked on the synthesis and the functionalization of new cryptophanes. (author) [fr

Factors and uncertainties in the profitability of using nuclear energy in desalination of water; Facteurs et incertitudes de la rentabilite du recours a l'energie nucleaire dans le dessalement des eaux

Energy Technology Data Exchange (ETDEWEB)

Thiriet, L; Lievre, P [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1969-07-01

durees de vie des materiels, selon le choix des materiaux, l'evolution des prix, la forme des fonctions de prix et les taux d'interet) et aux contraintes. Dans une deuxieme partie, on etudie et on discute les incertitudes liees, a la methode d'optimisation utilisee et au critere de choix retenu. On montre ainsi qu'il est extremement difficile dans la plupart des cas de conclure sans nuances a la competitivite ou, a l'inverse, a la non competitivite du recours a l'energie nucleaire dans le dessalement des eaux et qu'un grand nombre d'aspects doivent etre soigneusement examines. (auteur)

Probing zeolite internal structures using very low temperature 129Xe NMR

International Nuclear Information System (INIS)

Labouriau, A.; Crawford, S.N.; Earl, W.L.; Pietrass, T.; Weber, W.A.; Panjabi, G.; Gates, B.C.

1998-01-01

In recent years, probing pore structure with 129 Xe NMR has received a bad reputation. This is due to the fact that the method is more complex than was originally suggested so the data is somewhat difficult to interpret. The authors find that the use of a wide temperature range (40--350 K) allows them to interpret 129 Xe chemical shifts in terms of van der Waals attraction between the xenon atom and oxygen in zeolite walls. Using rather simple models from the literature, they can extract useful pore size information as well as the van der Waals potential energy

Medical Isotope Program: O-18, C-13, and Xe-129 Final Report CRADA No. TC-2043-02

Energy Technology Data Exchange (ETDEWEB)

Scheibner, K. F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Fought, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-09-27

This was a collaborative effort between the University of California, Lawrence Livermore National Laboratory (LLNL) and Spectra Gases, Inc., to develop new and cheaper sources of Oxgyen-18 (O-18), Carbon-13 (C-13), and Xenon-129 (Xe-129), and to develop new applications of these stable medical isotopes in medicine resulting in a substantial increase in stable isotopes that are important to human health sciences.

Analytic index for nuclear physicians uses; Repertoire analytique a l'usage des physiciens nucleaires

Energy Technology Data Exchange (ETDEWEB)

Ballini, R.; Barloutaud, R.; Bernas, R.; Bretonneau, P.; Chaminade, R.; Cohen, R.; Conjeaud, M.; Cotton, E.; Faraggi, H.; Grjebine, T.; Joffre, H.; Laboulaye, H. de; Lesueur, C.; Leveque, A.; Moreau, J.; Naggiar, V.; Papineau, L.; Prugne, P.; Schuhl, C.; Studinowski, FJ.; Netter, F.; Raievski, V.; Valladas, G. [Commissariat a l' Energie Atomique, Lab. du Fort de Chatillon, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires; Marty, N.; Renard, G. [College de France, Lab. de Chimie Nucleaire (France)

The problem of the documentation in nuclear physics becomes constantly more complex. Every week brings its share of new publications, always more numerous and more varied. To remedy to this facts that we tried, in the service of Nuclear Physics of the CEA, to give to the documentation a character of a collective and systematized work. The present report covers the literature appeared between first January 1950 and first July 1951. (Volume 1: CEA report number 120; Volume 2: CEA report number 184). (M.B.) [French] Le probleme de la documentation en physique nucleaire devient sans cesse plus complexe. Chaque semaine apporte son lot de publications, toujours plus nombreuses et plus diversifiees. C'est pour essayer de porter remede a cet etat de choses que nous avons essaye, au service de Physique Nucleaire du C.E.A., de donner a la documentation le caractere d'un travail collectif systematise. Le present rapport couvre la litterature parue entre le premier Janvier 1950 et le premier Juillet 1951. (Tome 1: Rapport CEA numero 120; Tome 2: Rapport CEA numero 184). (M.B.)

Neutron noise in nuclear reactors; Le bruit neutronique des reacteurs nucleaires

Energy Technology Data Exchange (ETDEWEB)

Blaquiere, A. [Institut National des Sciences et Techniques Nucleaires (France); Pachowska, R. [Universite Technique de Varsovie (Poland)

1961-06-15

The power of a nuclear reactor, in the operating conditions, presents fluctuations due to various causes. This random behaviour can be included in the study of 'noises'. Among other sources of noise, we analyse hereafter the fluctuations due: a) to the discontinuous emissions of neutrons from an independent source; b) to the multiplication of neutrons inside the reactor. The method which we present makes use of the analogies between the rules governing a nuclear reactor in operation and a number of radio-electrical systems, in particular the feed-back loops. The reactor can be characterized by its 'passing band' and is described as a system submitted to a sequence of random pulses. In non linear operating condition, the effect of neutron noise is defined by means of a non-linear functional, this theory is thus related to previous works the references of which are given at the end of the present report. This leads us in particular in the case of nuclear reactors to some results given by A. Blaquiere in the case of radio-electrical loops. (author) [French] La puissance d'un reacteur nucleaire, dans les conditions du regime, est affectee de fluctuations dont les causes sont tres diverses. Ce comportement aleatoire rentre dans le cadre general de l'etude des 'bruits'. Entre autres sources ce bruit, nous analysons ici les fluctuations dues: a) a l'emission discontinue des neutrons provenant d'une source autonome; b) a la multiplication des neutrons au sein du reacteur. La methode que nous introduisons exploite les analogies entre les lois qui regissent un reacteur nucleaire au regime et certains systemes radioelectriques, en particulier les circuits a boucle de reaction. Le reacteur est caracterise par sa 'bande passante' et est decrit comme un systeme soumis a une succession d'impulsions aleatoires. Dans les conditions de fonctionnement non lineaires, l'effet du bruit neutronique est precise en utilisant une fonctionnelle non lineaire, ce qui relie cette theorie a

Tracing the Iodine-129 fallout in Argentina

Energy Technology Data Exchange (ETDEWEB)

Fernandez Niello, Jorge; Negri, Agustin; Arazi, Andres [Comision Nacional de Energia Atomica (CNEA), Buenos Aires (Argentina). Lab. TANDAR; Wallner, Anton [The Australian National University, Canberra (Australia). Dept. of Nuclear Physics; Niello, Jorge Fernandez [Universidad Nacional de San Martin, Campus Miguelete, Buenos Aires (Argentina)

2012-07-01

Full text: Long-lived {sup 129}I (half-life=15.6 Ma) is produced naturally by irradiation of atmospheric xenon by cosmic neutrons and in the sub-surface by spontaneous fission of {sup 238}U, from which the natural inventory of {sup 129}I has been estimated to be around 50,000 kg, only 140 kg of them corresponds to the hydrospheric inventory. Nuclear tests and accidents have added between 45-130 kg. Apart from a global atmospheric fallout component, {sup 129}I has been released from several nuclear fuel reprocessing plants located in the Northern Hemisphere (ca. 6000 kg) which serve as localized sources in oceanographic-tracer experiments. In this presentation, we report results from a study exploring the presence of {sup 129}I in the Southern Hemisphere by determining {sup 129}I/{sup 127}I isotopic ratios in water samples (rivers, lakes and shallow sea-water) taken at different latitudes in Argentina including Antarctica. The iodine-127 and iodine-129 concentrations were measured via ICP-MS (Inductively Coupled Plasma Mass Spectrometry) and Accelerator Mass Spectrometry (AMS), respectively. Distribution of both isotopes can be understood considering tropospheric circulation patterns, possible sources and regional precipitation patterns. Natural and anthropogenic sources for the Southern Hemisphere and their inventories are discussed. Similar contribution came from natural sources and nuclear tests. Contribution from the nuclear fuel reprocessing plants placed in the Northern hemisphere can be neglected. (author)

A study of the fluorescence of the rare gases excited by nuclear particles. Use of the principle for the detection of nuclear radiation by scintillation; Etude de la fluorescence des gaz rares excites par des particules nucleaires. Utilisation pour la detection des rayonnements nucleaires par scintillation

Energy Technology Data Exchange (ETDEWEB)

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

1959-12-15

composantes, l'une tres breve due a la desexcitation directe du gaz rare, l'autre relativement plus lente, due au transfert d'energie sur les impuretes. La mesure des durees de vie des etats excites a confirme l'hypothese precedente, la partie breve de l'impulsion est extremement courte: inferieure a 2,25.10{sup -9} s dans le cas du xenon, la partie plus lente a une duree qui depend etroitement de la concentration d'azote, l'azote etant l'impurete dont le role est preponderant dans tous les cas. L'etude des gaz rares soumis a un champ electrique a permis de montrer que la quantite de lumiere produite par une particule {alpha} peut etre multipliee (par 60 dans un champ de 600 V/cm par exemple) ce qui correspond a un rendement de luminescence superieur a celui de INa TI. Dans la deuxieme partie on a etudie les caracteristiques des gaz rares comme scintillateurs, la plus importante est l'absence de saturation de la fluorescence lorsque la densite d'excitation transmise au gaz devient tres grande. Ceci joint au temps de scintillation tres court a permis d'etudier un certain nombre d'applications a la physique nucleaire (mesure d'energie des particules lourdes, etude cinetique des reacteurs nucleaires, spectroscopie des neutrons...). (auteur)

MR imaging of the stomach and relaxation measurement with intraluminal hyperpolarized 129Xenon gas

International Nuclear Information System (INIS)

Yanagawa, Yasuhiro; Kimura, Atsuomi; Fujiwara, Hideaki; Kinoshita, Yoshimasa; Hattori, Mineyuki; Hiraga, Takashi; Iida, Hidehiro

2001-01-01

Using laser optical pumping, the nuclear spin polarization of noble gases can be strongly enhanced. The purpose of this study was to make a simple apparatus that can provide hyperpolarized 129 Xe gas, which can then be used in an attempt to obtain magnetic resonance imaging (MRI). We would also like to study the relaxation behavior of hyperpolarized 129 Xe gas through the measurement of the relaxation time. First, we demonstrated that hyperpolarized 129 Xe gas can be applied to magnetic resonance imaging of the stomach, by using a rat as a model. This was performed under a 4.7 T magnet field using the following imaging parameters for the hyperpolarized 129 Xe gas: TR=50 ms, TE=15 ms, FOV=10 x 10 cm 2 , matrix size 64 x 64, THK=2.54 cm. By using these parameters, we were able to obtain a hyperpolarized image of the stomach in rats for the first time. Next, we measured the relaxation times of the hyperpolarized 129 Xe gas enclosed in cavities such as the stomach of rats as well as in phantoms created by glass and gelatin bulbs. The cavity size dependency of the relaxation time was analyzed on the basis of the kinetic theory of gases. This analysis showed a linear relationship between the relaxation rate (1/T 1 ) and a square inverse of the cavity diameter (1/d 2 ). From this relationship, the wall effect on the 129 Xe relaxation can be estimated in the novel parameter t 1 , wall . This shows drastic dependency on the material of the wall, suggesting a potential use of the relaxation experiment as a diagnostic tool for organ surfaces in the future. (author)

Production of nuclear graphite in France; Production de graphite nucleaire en France

Energy Technology Data Exchange (ETDEWEB)

Legendre, P; Mondet, L [Societe Pechiney, 74 - Chedde (France); Arragon, Ph; Cornuault, P; Gueron, J; Hering, H [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1955-07-01

The graphite intended for the construction of the reactors is obtained by the usual process: confection of a cake from coke of oil and tar, cooked (in a electric oven) then the product of cook is graphitized, also by electric heating. The use of the air transportation and the control of conditions cooking and graphitization have permitted to increase the nuclear graphite production as well as to better control their physical and mechanical properties and to reduce to the minimum the unwanted stains. (M.B.) [French] Le graphite destine a la construction des reacteurs est obtenu par le procede usuel: confection d'une pate a partir de coke de petrole et de brai, cuisson de cette pate (au four electrique) puis graphitation du produit cuit, egalement par chauffage electrique. L'usage du transport pneumatique et le controle des conditions cuisson et de graphitation ont permit d'augmenter la production de graphite nucleaire ainsi que de mieux controler ses proprietes physiques et mecaniques et de reduire au minimum les souillures accidentelles. (M.B.)

Positron annihilation and 129Xe NMR studies of free volume in polymers

International Nuclear Information System (INIS)

Nagasaka, Bunsow; Eguchi, Taro; Nakayama, Hirokazu; Nakamura, Nobuo; Ito, Yasuo

2000-01-01

The existence and the average size of free volume in bisphenol-A polycarbonate (PC), low-density polyethylene (LDPE), poly (2,6-dimethyl-phenylene oxide)(PPO), and polytetrafluoroethylene (PTFE) were studied by positron annihilation and 129 Xe NMR measurements. The 129 Xe NMR chemical shifts for xenon adsorbed in the polymers indicated that the average pore size of the free volume increased in the following order: PC, LDPE, PPO, and PTFE. This order of the pore size of the free volume agrees well with that estimated from the longest lifetime (τ 3 ) of ortho-positronium formed in the polymers. The unique correlation that δ -1 ∝ r is established between the 129 Xe NMR chemical shift (δ) and the pore size (r), which is deduced from the positron annihilation measurements.

Analytic catalog for the use of the nuclear physicists; Repertoire analytique a l'usage des physiciens nucleaires

Energy Technology Data Exchange (ETDEWEB)

Ballini, R; Barloutaud, R; Bernas, R; Chaminade, R; Cohen, R; Conjeaud, M; Cotton, E; Faraggi, H; Grjebine, T; Laboulaye, H de; Lehmann, P; Leveque, A; Levi, C; Moreau, J; Naggiar, V; Olkowsky, J; Papineau, L; Papineau, L; Prugne, P; Schuhl, C; Szteinsznaider, D; Tzara, C; Valladas, G [Commissariat a l' Energie Atomique, Saclay(France). Centre d' Etudes Nucleaires; Marty, N; Renard, G [College de France, Lab. de Chimie Nucleaire (France)

1952-07-01

The problem of the documentation in nuclear physics becomes constantly more complex. Every week brings its share of publications, always more numerous and more varied. To remedy to this problem, we tried, at the Nuclear Physics Services of the CEA, to give to the documentation the character of a collective and systematized work. The present report covers the literature appeared between January 1, 1950 and July 1, 1951. (Volume 1: CEA report number 120; Volume 2: CEA report number 184). (M.B.) [French] Le probleme de la documentation en physique nucleaire devient sans cesse plus complexe. Chaque semaine apporte son lot de publications, toujours plus nombreuses et plus diversifiees. C'est pour essayer de porter remede a cet etat de choses que nous avons essaye, au service de Physique Nucleaire du C.E.A., de donner a la documentation le caractere d'un travail collectif systematise. Le present rapport couvre la litterature parue entre le 1 Janvier 1950 et le 1 Juillet 1951. (Tome 1: Rapport CEA numero 120; Tome 2: Rapport CEA numero 184). (M.B.)

Differential measurement of the earth's magnetic field by nuclear magnetic resonance; Mesure differentielle du champ magnetique terrestre par resonance magnetique nucleaire

Energy Technology Data Exchange (ETDEWEB)

Robach, F [Commissariat a l' Energie Atomique, 38 - Grenoble (France). Centre d' Etudes Nucleaires

1967-07-01

MNR transducers using proton dynamic polarisation allows to convert into a phase measurement any variation of the earth magnetic field. There exist several versions of the instrument corresponding to various models of MNR transducers, which the author analyses in detail, devoting an important place to influence of their alignment with respect to the earth's magnetic field. The sensibility obtained is of one hundredth of a gamma over a bandwidth of (0-0,1 Hz). - This instrument is designed for measuring field gradients in airborne magnetic surveying, for detecting nearly magnetic anomalies, and for distinguishing between nearly and distant magnetic phenomena. (author) [French] L'emploi de capteurs, bases sur la resonance magnetique nucleaire des protons en presence de polarisation dynamique, permet de traduire une difference de champ magnetique terrestre en une mesure de phase. L'appareil existe sous plusieurs versions avec des capteurs de modeles differents dont l'auteur fait une analyse detaillee en accordant une part importante a l'influence de l'orientation des capteurs par rapport au champ magnetique terrestre. La sensibilite est de 1/100 {gamma} pour une bande passante de (0 - 0,1 Hz). Cet appareil s'applique a la mesure du gradient en prospection magnetique aeroportee, a la detection d'anomalies magnetiques proches, a la differentiation d'effets magnetiques proches et lointains. (auteur)

Molecular MRI based on hyper-polarized xenon

International Nuclear Information System (INIS)

Tassali, Nawal

2012-01-01

Magnetic Resonance Imaging (MRI) has a high importance in medicine as it enables the observation of the organs inside the body without the use of radiative or invasive techniques. However it is known to suffer from poor sensitivity. To circumvent this limitation, a key solution resides in the use of hyper-polarized species. Among the entities with which we can drastically increase nuclear polarization, xenon has very specific properties through its interactions with its close environment that lead to a wide chemical shift bandwidth. The goal is thus to use it as a tracer. This PhD thesis focuses on the concept of 129 Xe MRI-based sensors for the detection of biological events. In this approach, hyper-polarized xenon is vectorized to biological targets via functionalized host systems, and then localized thanks to fast dedicated MRI sequences. The conception and set-up of a spin-exchange optical pumping device is first described. Then studies about the interaction of the hyper-polarized noble gas with new cryptophanes susceptible to constitute powerful host molecules are detailed. Also the implementation of recent MRI sequences optimized for the transient character of the hyper-polarization and taking profit of the xenon in-out exchange is described. Applications of this approach for the detection of metallic ions and cellular receptors are studied. Finally, our first in vivo results on a small animal model are presented. (author) [fr

Neon and xenon isotopes in MORB: Implications for the earth-atmosphere evolution

International Nuclear Information System (INIS)

Marty, B.

1989-01-01

The isotopic composition of neon and xenon measured in MORB glasses confirm significant deviations from atmospheric values. There are 1. 21 Ne excesses with are attributed to nucleogenic reactions in the mantle; 2. 20 Ne/ 22 Ne ratios higher than the air ratio interpreted as an evidence for the occurrence of solar-type Ne at depth; 3. 129 Xe and 131-136 Xe excesses, attributed to both extinct ( 129 I and 244 Pu) and present ( 238 U) radioactivities. Ne and Xe isotopic signatures in the mantle can hardly be explained in the framework of classical models for the atmospheric evolution (which postulate a mantle origin for atmospheric gases) and appeal for at least two sources of gases. Ne isotopic differences between air and MORB appear too large to be accounted for by any reasonable fractionation process in the mantle. They imply either fractionation of neon during hydrodynamic escape of a primary atmosphere or different degrees of mixing between primordial Ne components, which, in turn imply isolation of the surface reservoir (air) and deep reservoir (mantle) from the accretional period (except for mantle outgassing through volcanism, the contribution of which is 41% at best for 20 Ne). 129 I- 129 Xe, 244 Pu- 238 U- 136 Xe systematics for atmospheric and MORB-type xenon suggest that either atmospheric gases derived from a source whose formation was delayed (≥ 17 Ma) with respect to the mean accretion time of the mantle source and/or atmospheric gases and MORB-type gases derived from chemically distinct sources. These features are consistent with heterogeneous accretion models for the Earth. Volatile degassing was probably contemporaneous to accretional events, following impact degassing, and might have been most efficient during the late stages of Earth formation. (orig.)

Analytic catalog for the use of the nuclear physicists; Repertoire analytique a l'usage des physiciens nucleaires

Energy Technology Data Exchange (ETDEWEB)

Ballini, R.; Barloutaud, R.; Bernas, R.; Chaminade, R.; Cohen, R.; Conjeaud, M.; Cotton, E.; Faraggi, H.; Grjebine, T.; Laboulaye, H. de; Lehmann, P.; Leveque, A.; Levi, C.; Moreau, J.; Naggiar, V.; Olkowsky, J.; Papineau, L.; Papineau, L.; Prugne, P.; Schuhl, C.; Szteinsznaider, D.; Tzara, C.; Valladas, G. [Commissariat a l' Energie Atomique, Saclay(France). Centre d' Etudes Nucleaires; Marty, N.; Renard, G. [College de France, Lab. de Chimie Nucleaire (France)

1952-07-01

The problem of the documentation in nuclear physics becomes constantly more complex. Every week brings its share of publications, always more numerous and more varied. To remedy to this problem, we tried, at the Nuclear Physics Services of the CEA, to give to the documentation the character of a collective and systematized work. The present report covers the literature appeared between January 1, 1950 and July 1, 1951. (Volume 1: CEA report number 120; Volume 2: CEA report number 184). (M.B.) [French] Le probleme de la documentation en physique nucleaire devient sans cesse plus complexe. Chaque semaine apporte son lot de publications, toujours plus nombreuses et plus diversifiees. C'est pour essayer de porter remede a cet etat de choses que nous avons essaye, au service de Physique Nucleaire du C.E.A., de donner a la documentation le caractere d'un travail collectif systematise. Le present rapport couvre la litterature parue entre le 1 Janvier 1950 et le 1 Juillet 1951. (Tome 1: Rapport CEA numero 120; Tome 2: Rapport CEA numero 184). (M.B.)

Krypton and xenon in the atmosphere of Venus

Science.gov (United States)

Donahue, T. M.; Hoffman, J. H.; Hodges, R. R., Jr.

1981-01-01

The paper reports a determination by the Pioneer Venus large probe neutral mass spectrometer of upper limits to the concentration of krypton and xenon along with most of their isotopes in the atmosphere of Venus. The upper limit to the krypton mixing ratio is estimated at 47 ppb, with a very conservative estimate at 69 ppb. The probable upper limit to the sum of the mixing ratios of the isotopes Xe-128, Xe-129, Xe-130, Xe-131, and Xe-132 is 40 ppb by volume, with a very conservative upper limit three times this large.

French research in the field of nuclear agronomy; Les recherches francaises en agronomie nucleaire

Energy Technology Data Exchange (ETDEWEB)

Guerin De Montgareuil, P [Commissariat a l' Energie Atomique, Cadarache (France). Centre d' Etudes Nucleaires

1964-07-01

, industrial firms, university laboratories scientific institutes. The role of the Commissariat a l'Energie Atomique is defined: on the one hand it supplies information and support, and on the other hand it takes charge of specifically nuclear aspects of the work. Its part in the field has recently found expression in the creation, within the Biology Department, of a Radio-agronomy Section; its objective are described,, as well as the, means placed att its disposal at the Centre d'etudes Nucleaires, Cadarache. (author) [French] On propose un bilan des travaux les plus significatifs effectues en France depuis la deuxieme conference internationale en matiere d'agronomie nucleaire et qui vont d'une recherche apparemment desinteressee a l'application la plus directe. Une telle differenciation recouvre de moins en moins, au fur et a mesure de l'evolution des programmes, la distinction qui est faite dans l'expose entre l'action biologique des rayonnements et les autres emplois des techniques nucleaires. C'est ainsi que les recherches do radiogenetique agricole sont poursuivies dans deux directions: d'un point de vue theorique et methodologique avec l'etude comparative de l'action des divers types de rayonnements, l'influence du debit de dose et de la temperature, l'action des agents mutagenes chimiques, la production de chimeres sous irradiation gamma; et d'autre part, sous un aspect pratique aboutissant a la creation de varietes nouvelles plus resistantes ou plus precoces (riz, mil, arachide). Les problemes de destruction des insectes (eradication) et de conservation des denrees sous irradiation se trouvent egalement abordes par des voies et avec des objectifs tres divers. A la demarche globale representee par une irradiation pure et simple (grains humides, pommes de terre...) sont parfois associees des etudes souvent originales, d'ordre biochimique ou microbiologique (par exemple: alteration de l'amidon, metabolisme glucidique des tubercules irradies, radioresistance des levures

Possibilities and limitations of analogue methods for studying the dynamics of nuclear power stations; Possibilites et limitations du calcul analogique pour les etudes dynamiques de centrales nucleaires

Energy Technology Data Exchange (ETDEWEB)

Caillet, C; Deat, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

'on decrit en discutant la validite des approximations choisies. 4. Les simulateurs de machines tournantes: on souligne le caractere particulier que presentent les calculs des machines tournantes en raison de la necessite ou l'on est de passer par l'intermediaire d'abaques. On propose l'utilisation d'une memoire a acces aleatoire permettant un traitement analogique de ces problemes. 5. Etude d'une centrale nucleaire: on etudie, sur un exemple, les problemes poses par l'interconnexion d'elements du type precedent pour la simulation de grands ensembles (centrales nucleaires) et on souligne le role des elements ordinaires de calcul. 6. Conclusion: on souligne la necessite pour toutes ces etudes, de disposer d'un materiel de qualite et on discute la signification des resultats ainsi obtenus. (auteur)

Contribution to thermodynamics and kinetics of argon, krypton and xenon at very low temperatures; Contribution a l'etude thermodynamique et cinetique de l'argon, du krypton et du xenon aux tres basses temperatures

Energy Technology Data Exchange (ETDEWEB)

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

1969-07-01

A critical analysis of the main theories of condensation, which are due to Zwanzig, Cabrera, Mc Caroll and Ehrlich, Wanlass, Armand, and Yu and Soo, is made. A condensation coefficient equal to unity is expected from these theories, except Armand and Yu and Soo, when the temperature of the gas impinging on its own solid phase is equal or less than 300 K. Using a resonating quartz microbalance the sensitivity of which is 10{sup -9} g. cm{sup 2} the experimental data agree with these theories when the temperature of the solid is less than 20 K. However the agreement must be interpreted for the more sophisticated theories of Armand and Yu and Soo. Regarding the sublimation of the rare gases one is faced with the theories of Salter, Eyring, Goodman and Armand. Within an order of magnitude the experimental data given here agree with the expected values. Moreover Armand theory is able to give the physical meaning of the observed results for argon sublimation from a krypton or a xenon crystalline substrate: localized modes of surface vibration occur. The relaxation time for the thermalization of the argon deposit is found greater than twelve hours at 25 K. (author) [French] Ce travail inclut l'etude critique des principales theories de la condensation dues a Zwanzig, Cabrera, Mc Caroll et Ehrlich, Wanlass, Armand, et Yu et Soo. Ces theories, sauf les deux dernieres, prevoient un coefficient de condensation egal a 1 lorsque le gaz incident sur son propre solide a une temperature inferieure ou egale a 300 K. Les mesures effectuees a l'aide d'une microbalance a quarz resonnant sensible a 10{sup -9} g. cm{sup 2} ont confirme ces theories dans le cas ou la temperature du solide est inferieure a 20 K. Cet accord doit cependant etre interprete pour les theories plus completes d'Armand d'une part, Yu et Soo d'autre part. Pour la sublimation des gaz rares on se trouve en presence des theories de Salter, Eyring, Goodman et Armand. Leurs previsions sont en accord, a un ordre de

Krypton and xenon in Apollo 14 samples - Fission and neutron capture effects in gas-rich samples

Science.gov (United States)

Drozd, R.; Hohenberg, C.; Morgan, C.

1975-01-01

Gas-rich Apollo 14 breccias and trench soil are examined for fission xenon from the decay of the extinct isotopes Pu-244 and I-129, and some samples have been found to have an excess fission component which apparently was incorporated after decay elsewhere and was not produced by in situ decay. Two samples have excess Xe-129 resulting from the decay of I-129. The excess is correlated at low temperatures with excess Xe-128 resulting from neutron capture on I-127. This neutron capture effect is accompanied by related low-temperature excesses of Kr-80 and Kr-82 from neutron capture on the bromine isotopes. Surface correlated concentrations of iodine and bromine are calculated from the neutron capture excesses.

Sud du Sahara | Page 129 | CRDI - Centre de recherches pour le ...

International Development Research Centre (IDRC) Digital Library (Canada)

Dans un nouveau documentaire fascinant, des chercheurs du Centre for the Study of Violence and Reconciliation font part de leurs observations sur la façon dont un programme d'emploi public de l'Afrique du Sud contribue à rendre les villes plus sécuritaires et inclusives. Read more about Un documentaire démontre ...

Special Nuclear Material Control by the Power Reactor Operator; Controle des Matieres Nucleaires Speciales par l'Exploitant d'une Centrale Nucleaire; Spetsial'nyj kontrol' nalichiya yadernykh materialov operatorom ehnergeticheskogo reaktora; Control de Materiales Nucleares Especiales por Parte de Quienes Operan el Reactor de Potencia

Energy Technology Data Exchange (ETDEWEB)

Cordin, R. A. [Yankee Atomic Electric Company, Boston, MA (United States)

1966-02-15

insurance programme. (author) [French] L'uranium, combustible relativement nouveau et extremement interessant pour la production d'electricite, doit faire l'objet d'un controle tres strict depuis le moment ou l'exploitant de la centrale en devient financierement responsable jusqu'a celui oti, sous forme de combustible partiellement epuise, la matiere est transferee dans une autre installation et oti l'on recupere ce qui reste de sa valeur initiale. La plupart des exploitants de centrales nucleaires dirigeaient des centrales alimentees par des combustibles fossiles avant l'avenement de l'energie nucleaire et ils ont etabli depuis longtemps un controle etendu et efficace de ces combustibles fossiles. L'exploitant d'une centrale nucleaire doit exercer un controle non moins efficace sur les matieres nucleaires speciales utilisees dans son installation. La technique de l'exploitation des centrales nucleaires n'est pas ancienne et, au cours de, son existence relativement breve, les ingenieurs et hommes de science des Etats-Unis ont constamment ameliore les plans des centrales et les methodes d'exploitation afin de reduire les couts et de permettre aux centrales nucleaires de concurrencer les centrales classiques. La gestion des matieres nucleaires doit etre aussi moderne et efficace que possible pour assurer que les progres technologiques grace auxquels les prix on pu etre reduits ne soient pas mis en echec par des insuffisances dans la manipulation du combustible nucleaire et la tenue de la comptabilite des stocks. Pour assurer la gestion des matieres nucleaires, il faut que l'exploitant de la centrale etablisse et tienne a jour une comptabilite complete et detaillee, sans etre necessairement complexe pour autant; en fait, la simplicite est extremement souhaitable. Bien que le combustible nucleaire soit nouveau et qu'il n'ait rien de commun avec les combustibles classiques, aucun secret ne doit s'y attacher. Le controle des matieres nucleaires dans le cadre de la gestion des

Calculation of the shock-wave in the region close to an underground nuclear explosion (method Cades); Calcul de l'onde de choc en zone proche d'une explosion nucleaire souterraine (methode cades)

Energy Technology Data Exchange (ETDEWEB)

Supiot, F; Brugies, J [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

1969-07-01

The outline of a method is presented for calculating the characteristics of a shock wave produced by an underground nuclear explosion (pressure, wave velocity, velocity of the medium, energy left in the medium by the shock, etc.). By means of an application to a granitic medium and of a comparison with results obtained during French nuclear explosions, it has been possible to show the good agreement existing between the calculations and the experimental results. The advantages of such a method for studying the industrial applications of underground nuclear explosions are stressed. (authors) [French] On expose les grandes lignes d'une methode de calcul des caracteristiques de l'onde de choc issue d'une explosion nucleaire souterraine (pression, vitesse de l'onde, vitesse du milieu, energie deposee par le choc dans le milieu...). Une application a un milieu granitique et une comparaison aux resultats obtenus au cours d'explosions nucleaires francaises permet de montrer la bonne concordance entre le calcul et les resultats experimentaux. On souligne l'interet d'une telle, methode pour l'etude d'applications industrielles des explosions nucleaires souterraines. (auteurs)

The use radioactive tracers in the study of solid transport in water streams; Emploi de traceurs radioactifs pour l'etude du transport solide dans les cours d'eau

Energy Technology Data Exchange (ETDEWEB)

Courtois, G [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires; Jaffry, P; Heuzel, M [Laboratoire National d' Hydraulique de Chatou, 78 (France)

1960-07-01

riviere, la premiere a ete consacree a l'etude du charriage des galets dans le Rhone, l'autre a l'etude des transports de sables dans le Niger. Cette derniere experience a ete doublee d'experiences identiques, effectuees sur le modele reduit du fleuve Niger exploite par le Laboratoire de Chatou: dans ces experiences, on utilise le rayonnement du {sup 56}Mn et du {sup 24}Na obtenu par activation directe du noyau d'abricot concasse representant sur le modele reduit le sediment naturel du lit du Niger. Les efforts conjugues du Laboratoire de Chatou et du Centre d'Etudes Nucleaires de Saclay portent actuellement sur l'application des traceurs radioactifs aux etudes sur modeles reduits, dans le double but: a) de disposer d'un meme moyen d'investigation en nature et sur modele reduit pour controler la fidelite du modele, dans la phase des essais d'etalonnage; b) de profiter des facilites d'observation et mesures directes offertes par les modeles reduits pour etudier les possibilites d'amelioration de la methode des traceurs, en particulier en ce qui concerne l'obtention de renseignements quantitatifs. (auteur)

Nuclear purity and the production of uranium (1962); La purete nucleaire et la fabrication de l'uranium (1962)

Energy Technology Data Exchange (ETDEWEB)

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

1962-07-01

When the production of 'nuclear grade' uranium is dealt with, it is difficult, the author of this study points out, to separate its chemical, technical, and economical bearings. While recalling the evolution of chemical processes in various countries and describing the technic of uranium manufacture in the plant of the French 'Commissariat a l'Energie Atomique' at Le Bouchet, the author outlines the effect of economical contingencies on the problems the chemists and engineer are faced with. The question of cost price is also considered here with particular attention. (author) [French] Lorsqu'il s'agit de la production d'uranium de 'qualite nucleaire', il est difficile, souligne l'auteur de cette etude, de separer les aspects chimique, technique et economique. Aussi, en retracant l'evolution des procedes chimiques dans divers pays et decrivant les techniques de fabrication de l'uranium a l'usine du Bouchet du Commissariat a l'Energie Atomique, l'auteur ne manque-t-il pas de rappeler les incidences de la conjoncture economique sur les problemes posees au chimiste et a l'ingenieur. La question du prix de revient, egalement, est traitee ici avec une attention particuliere. (auteur)

Staff Organization in Nuclear Power Stations; Organisation du personnel des centrales nucleaires; Organizatsiya personala na atomnykh ehlektrostantsiyakh; Organizacion del personal de las centrales nucleares

Energy Technology Data Exchange (ETDEWEB)

Scuricini, G. B. [Comitato Nazionale Energia Nucleare, Roma (Italy)

1963-10-15

This paper deals with the organization of operating and maintenance staff at nuclear power stations in Italy and manpower variations, either because the plants themselves differ or are organized in some special way. Staff doing jobs for which a specific training is required are given special consideration in the paper. (author) [French] Dans le memoire, on examine l'organisation du personnel d'exploitation et d'entretien des centrales nucleaires italiennes et les differences existant dans les effectifs, differences dues soit aux caracteristiques des centrales memes, soit aux particularites d'organisation des entreprises. Le personnel charge de fonctions determinees pour lesquelles un entrainement special est requis, fait l'objet d'une attention particuliere. (author) [Spanish] En la memoria se examina la organizacion del personal de explotacion y conservacion de las centrales nucleares italianas y las diferencias que existen entre sus efectivos, diferencias que se deben a las caracteristicas de las mismas centrales o a las particularidades de organizacion de las empresas. El autor dedica especial atencion al personal encargado de funciones que requieren una formacion profesional especial. (author) [Russian] Issleduyutsya voprosy organizatsii personala, zanimayushchegosya ehkspluatatsiej ital'yanskikh atomnykh ehlektrostantsij i ukhodom za nimi, a takkhe razlichiya v sostave personala, vytekayushchie libo iz kharakternykh osobennostej samikh stantsij, libo iz osobennostej organizatsii predpriyatij. Osoboe vnimanie udelyaetsya personalu, kotoromu porucheny opredelennye funktsii, trebuyushchie spetsial'noj pod go tovki. (author)

French research in the field of nuclear agronomy; Les recherches francaises en agronomie nucleaire

Energy Technology Data Exchange (ETDEWEB)

Guerin De Montgareuil, P. [Commissariat a l' Energie Atomique, Cadarache (France). Centre d' Etudes Nucleaires

1964-07-01

, industrial firms, university laboratories scientific institutes. The role of the Commissariat a l'Energie Atomique is defined: on the one hand it supplies information and support, and on the other hand it takes charge of specifically nuclear aspects of the work. Its part in the field has recently found expression in the creation, within the Biology Department, of a Radio-agronomy Section; its objective are described,, as well as the, means placed att its disposal at the Centre d'etudes Nucleaires, Cadarache. (author) [French] On propose un bilan des travaux les plus significatifs effectues en France depuis la deuxieme conference internationale en matiere d'agronomie nucleaire et qui vont d'une recherche apparemment desinteressee a l'application la plus directe. Une telle differenciation recouvre de moins en moins, au fur et a mesure de l'evolution des programmes, la distinction qui est faite dans l'expose entre l'action biologique des rayonnements et les autres emplois des techniques nucleaires. C'est ainsi que les recherches do radiogenetique agricole sont poursuivies dans deux directions: d'un point de vue theorique et methodologique avec l'etude comparative de l'action des divers types de rayonnements, l'influence du debit de dose et de la temperature, l'action des agents mutagenes chimiques, la production de chimeres sous irradiation gamma; et d'autre part, sous un aspect pratique aboutissant a la creation de varietes nouvelles plus resistantes ou plus precoces (riz, mil, arachide). Les problemes de destruction des insectes (eradication) et de conservation des denrees sous irradiation se trouvent egalement abordes par des voies et avec des objectifs tres divers. A la demarche globale representee par une irradiation pure et simple (grains humides, pommes de terre...) sont parfois associees des etudes souvent originales, d'ordre biochimique ou microbiologique (par exemple: alteration de l

Problems related with the power regulation of reactors by physico-chemical methods, and the behaviour of water and heavy water in nuclear reactors; Comportement de l'eau et de l'eau lourde dans les reacteurs nucleaires et problemes de la regulation de puissance par voie physico-chimique

Energy Technology Data Exchange (ETDEWEB)

Dolle, L; Conan, D; Dirian, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

Experience of the CEA heavy water reactors and a systematic study of the radiolytic decomposition of water in the core of swimming-pool reactors are described. Setting up of reactivity control by physico-chemical methods. Reactivity control by homogeneous poisoning of the reactor A comparison of the evolution of xenon poisoning with the residual anti reactivity of the poison in solution during its nuclear consumption establishes the programme which must govern the variation in its concentration if the exact compensation is to be produced The behaviour of the poison towards the reactor materials under the particular operational conditions must be taken into account. Radiolytic decomposition of water in the reactors in the presence of soluble poisons: A study of the effect of certain chemically inert salts, present in small concentrations in the water, on its radiolytic decomposition rate, has led to some new results which are discussed. The choice of a soluble poison is justified on the basis of the above results. Reactivity control by the use of a gaseous absorbent The use of a gas control rod circuit for compensation purposes, in place of solid control rods is described. The use of soluble poisons in the moderator to compensate the xenon effect, and of a gaseous absorbent in a circuit known as a gas control rod form original aspects of the reactivity control in the reactor EL 4. (authors) [French] L'observation du comportement de l'eau et de l'eau lourde dans les reacteurs en exploitation, contribue au fonctionnement sur de ceux-ci et oriente certaines etudes relatives aux techniques de controle de la reactivite par mise en oeuvre de poisons solubles. L'utilisation de poisons nucleaires dissous dans l'eau du reacteur entraine une pollution chimique de celle-ci. Les conditions d'emploi permettant d'eviter les effets indesirables de cette pollution sont etudiees. Les problemes analytiques - bien qu'importants - ne sont pas abordes dans le cadre de la communication

Statistical treatment of data. Application to nuclear electronics; Traitement des informations en regime statistique. Applications a l'electronique nucleaire

Energy Technology Data Exchange (ETDEWEB)

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

1960-07-01

In this report the data of probability calculations are applied to the analyses of counting losses in experiments on chance events encountered in nuclear physics. The distribution of time intervals according to Poisson's law is studied and various applications of this are given: calculation of counting losses on a scale preceded by a fast de-multiplying circuit, decrease of the counting rate on the multichannel selectors, recording of statistical distribution phenomena on magnetic bands. (author) [French] Ce rapport applique les donnees du calcul des probabilites a l'analyse des pertes de comptage dans les experiences sur des evenements aleatoires rencontres en physique nucleaire. La distribution des intervalles de temps suivant une loi de Poisson est etudiee et differentes applications en sont donnees: calcul des pertes de comptage sur une echelle precedee d'un circuit de demultiplication rapide, diminution du taux de comptage sur les selecteurs multicanaux, enregistrement de phenomenes a distribution statistique sur bandes magnetiques. (auteur)

ATLAS Event Display: First Xenon-Xenon Run 2017

CERN Multimedia

ATLAS Collaboration

2017-01-01

Event display from the xenon-xenon collision run of 12-13 October 2017. Curved cyan lines show the trajectories of charged particles in the tracking systems. The bottom right plot shows the distribution of energy deposited in the calorimeters, demonstrating the high particle multiplicity of the event. Two muon candidates are reconstructed at high pseudorapidity, as seen in the bottom left plot

Appropriate xenon-inhalation speed in xenon-enhanced CT using the end-tidal gas-sampling method

International Nuclear Information System (INIS)

Suga, Sadao; Toya, Shigeo; Kawase, Takeshi; Koyama, Hideki; Shiga, Hayao

1986-01-01

This report describes some problems when end-tidal xenon gas is substituted for the arterial xenon concentration in xenon-enhanced CT. The authors used a newly developed xenon inhalator with a xenon-gas-concentration analyzer and performed xenon-enhanced CT by means of the ''arterio-venous shunt'' method and the ''end-tidal gas-sampling'' method simultaneously. By the former method, the arterial build-up rate (K) was obtained directly from the CT slices of a blood circuit passing through the phantom. By the latter method, it was calculated from the xenon concentration of end-tidal gas sampled from the mask. The speed of xenon supply was varied between 0.6 - 1.2 L/min. in 11 patients with or without a cerebral lesion. The results revealed that rapid xenon inhalation caused a discrepancy in the arterial K between the ''shunt'' method and the ''end-tidal'' method. This discrepancy may be responsible for the mixing of inhalated gas and expired gas in respiratory dead space, such as the nasal cavity or the mask. The cerebral blood flow was underestimated because of the higher arterial K in the latter method. Too much slow inhalation, however, was timewasting, and it increased the body motion in the subanesthetic state. Therefore, an inhalation speed of the arterial K of as much as 0.2 was ideal to represent the end-tidal xenon concentration for the arterial K in the ''end-tidal gas-sampling'' method. When attention is given to this point, this method may offer a reliable absolute value in xenon-enhanced CT. (author)

Effect of cobalt-60 {gamma} radiation and of thermal neutrons on high resistance P and N silicon. Possibility of obtaining a nuclear compensation for P type silicon; Effects du rayonnement {gamma} du cobalt 60 et de neutrons thermiques sur du silicium P et N de haute resistivite. Possibilite de realiser une compensation nucleaire d'un silicium du type P

Energy Technology Data Exchange (ETDEWEB)

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

1965-11-01

Type P silicon has been compensated by the production of a controlled and uniform amount of donor atoms ({sup 31}P) using thermal neutrons to bring about a nuclear transformation. It is shown that it is possible in this way to reduce by a factor of about one hundred the overall concentration of residual ionised impurities in the purest crystals obtained by floating zone purification (2 x 10{sup 12} atoms/cm{sup 3}). The degree compensation obtained is limited by the initial inhomogeneity of acceptor impurities which have to be compensated. Lattice defects which still remain after prolonged annealings reduce the life-time of the material to about 10 {mu}s approximately. Particle detectors having thicknesses of 2 to 5 mm have been built by this process; they give good results, particularly at low temperatures. A study has also been made of the number and of the nature of lattice defects produced by thermal neutrons in high resistivity P and N type crystals. These defects have been compared to those produced by {gamma} rays from {sup 60}Co. A discussion is given of the validity of the Wertheim model concerning pronounced recombination at low temperatures (77 deg. K - 300 deg. K) of primary defect-interstitial pairs. The nature of the defects introducing energy levels into the lower half of the forbidden band has been studied. (author) [French] On a compense du silicium de type P en produisant, au moyen de neutrons thermiques, par transmutation nucleaire une quantite controlee et uniforme d'atomes donneurs ({sup 31}P). On montre qu'on peut ainsi reduire de cent fois environ la densite nette d'impuretes ionisees residuelles subsistant dans les cristaux les plus purs obtenus par purification par zone flottante (2.10{sup 12} atomes/cm{sup 3}). Le degre de compensation obtenu est limite par i'inhomogeneite initiale des impuretes acceptrices a compenser. Des defauts de reseau qui subsistent meme apres des recuits prolonges reduisent la duree de vie du materiau a 10 {mu

Pairwise additivity in the nuclear magnetic resonance interactions of atomic xenon.

Science.gov (United States)

Hanni, Matti; Lantto, Perttu; Vaara, Juha

2009-04-14

Nuclear magnetic resonance (NMR) of atomic (129/131)Xe is used as a versatile probe of the structure and dynamics of various host materials, due to the sensitivity of the Xe NMR parameters to intermolecular interactions. The principles governing this sensitivity can be investigated using the prototypic system of interacting Xe atoms. In the pairwise additive approximation (PAA), the binary NMR chemical shift, nuclear quadrupole coupling (NQC), and spin-rotation (SR) curves for the xenon dimer are utilized for fast and efficient evaluation of the corresponding NMR tensors in small xenon clusters Xe(n) (n = 2-12). If accurate, the preparametrized PAA enables the analysis of the NMR properties of xenon clusters, condensed xenon phases, and xenon gas without having to resort to electronic structure calculations of instantaneous configurations for n > 2. The binary parameters for Xe(2) at different internuclear distances were obtained at the nonrelativistic Hartree-Fock level of theory. Quantum-chemical (QC) calculations at the corresponding level were used to obtain the NMR parameters of the Xe(n) (n = 2-12) clusters at the equilibrium geometries. Comparison of PAA and QC data indicates that the direct use of the binary property curves of Xe(2) can be expected to be well-suited for the analysis of Xe NMR in the gaseous phase dominated by binary collisions. For use in condensed phases where many-body effects should be considered, effective binary property functions were fitted using the principal components of QC tensors from Xe(n) clusters. Particularly, the chemical shift in Xe(n) is strikingly well-described by the effective PAA. The coordination number Z of the Xe site is found to be the most important factor determining the chemical shift, with the largest shifts being found for high-symmetry sites with the largest Z. This is rationalized in terms of the density of virtual electronic states available for response to magnetic perturbations.

Hyperpolarized Xenon Nuclear Magnetic Resonance (NMR of Building Stone Materials

Directory of Open Access Journals (Sweden)

Michele Mauri

2012-09-01

Full Text Available We have investigated several building stone materials, including minerals and rocks, using continuous flow hyperpolarized xenon (CF-HP NMR spectroscopy to probe the surface composition and porosity. Chemical shift and line width values are consistent with petrographic information. Rare upfield shifts were measured and attributed to the presence of transition metal cations on the surface. The evolution of freshly cleaved rocks exposed to the atmosphere was also characterized. The CF-HP 129Xe NMR technique is non-destructive and it could complement currently used techniques, like porosimetry and microscopy, providing additional information on the chemical nature of the rock surface and its evolution.

Underground nuclear explosions. Geological survey of the cavities; Explosions nucleaires souterraines etude geologique des cavites

Energy Technology Data Exchange (ETDEWEB)

Faure, J [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

1969-07-01

A geological survey of underground nuclear explosions makes it possible to determine the main characteristics of the cavity formed. The lower portion is spherical; the same was very likely true of the roof, which collapses in the majority of media with the exception of rock-salt. Its radius, for a given bomb size, can vary by a factor of two according to the type of rock. The lay-out of its contents depends on the characteristics of the solid and liquid products at the moment of the roof collapse; according to the medium involved, mixing of the rubble and the mud-flow occurs (granite) or does not occur (tuff and alluvia). In all media, the average physical properties can be evaluated. (author) [French] L'etude geologique d'explosions nucleaires souterraines permet de determiner les principaux caracteres de la cavite creee. Sa partie inferieure est spherique; il en etait vraisemblablement de meme de sa voute, effondree dans la plupart des milieux a l'exception du sel gemme. Son rayon, a energie d'engin egale, varie selon les roches du simple au double. La disposition de son contenu depend des caracteristiques des produits solides et liquides au moment de la chute du toit; selon le cas, il n'y a pas (tuf et alluvions) ou il y a (granite) melange des eboulis et des laves. Dans tous les milieux, les proprietes physiques moyennes peuvent etre evaluees. (auteur)

SPALAX new generation: New process design for a more efficient xenon production system for the CTBT noble gas network.

Science.gov (United States)

Topin, Sylvain; Greau, Claire; Deliere, Ludovic; Hovesepian, Alexandre; Taffary, Thomas; Le Petit, Gilbert; Douysset, Guilhem; Moulin, Christophe

2015-11-01

The SPALAX (Système de Prélèvement Automatique en Ligne avec l'Analyse du Xénon) is one of the systems used in the International Monitoring System of the Comprehensive Nuclear Test Ban Treaty (CTBT) to detect radioactive xenon releases following a nuclear explosion. Approximately 10 years after the industrialization of the first system, the CEA has developed the SPALAX New Generation, SPALAX-NG, with the aim of increasing the global sensitivity and reducing the overall size of the system. A major breakthrough has been obtained by improving the sampling stage and the purification/concentration stage. The sampling stage evolution consists of increasing the sampling capacity and improving the gas treatment efficiency across new permeation membranes, leading to an increase in the xenon production capacity by a factor of 2-3. The purification/concentration stage evolution consists of using a new adsorbent Ag@ZSM-5 (or Ag-PZ2-25) with a much larger xenon retention capacity than activated charcoal, enabling a significant reduction in the overall size of this stage. The energy consumption of the system is similar to that of the current SPALAX system. The SPALAX-NG process is able to produce samples of almost 7 cm(3) of xenon every 12 h, making it the most productive xenon process among the IMS systems. Copyright © 2015 Elsevier Ltd. All rights reserved.

Novel methods and applications of NMR and MRI. Low-power RF excitation and hyperpolarized Xenon-129

International Nuclear Information System (INIS)

Amor, Nadia

2012-01-01

Since their discovery in the middle of the last century, Nuclear Magnetic Resonance (NMR) and Magnetic Resonance Imaging (MRI) have become an important and very versatile tool in industry, medicine, and basic research. The aim of this work is to explore possible improvements and new applications of NMR methods. First, a recently introduced excitation NMR pulse sequence, termed Frank sequence excitation, which allows for significant reduction of rf-excitation power, is systematically analyzed and compared to conventional NMR in detail. Furthermore, its feasibility for MRI is investigated and advantages as well as drawbacks in comparison to standard MRI are discussed. The second part focuses on new biomedical applications of hyperpolarized (HP) 129 Xe which not only offers a signal enhancement of several orders of magnitude but also provides new contrast mechanisms. A setup for continuous dissolution of HP 129 Xe gas into blood and other fluids is optimized and analyzed quantitatively by NMR and MRI. On the basis of these results, blood-dissolved HP 129 Xe is used to investigate blood-gas dynamics, as well as the rheological behavior of blood.

Simultaneous detection of xenon and krypton in equine plasma by gas chromatography-tandem mass spectrometry for doping control.

Science.gov (United States)

Kwok, Wai Him; Choi, Timmy L S; So, Pui-Kin; Yao, Zhong-Ping; Wan, Terence S M

2017-02-01

Xenon can activate the hypoxia-inducible factors (HIFs). As such, it has been allegedly used in human sports for increasing erythropoiesis. Krypton, another noble gas with reported narcosis effect, can also be expected to be a potential and less expensive erythropoiesis stimulating agent. This has raised concern about the misuse of noble gases as doping agents in equine sports. The aim of the present study is to establish a method for the simultaneous detection of xenon and krypton in equine plasma for the purpose of doping control. Xenon- or krypton-fortified equine plasma samples were prepared according to reported protocols. The target noble gases were simultaneously detected by gas chromatography-triple quadrupole mass spectrometry using headspace injection. Three xenon isotopes at m/z 129, 131, and 132, and four krypton isotopes at m/z 82, 83, 84, and 86 were targeted in selected reaction monitoring mode (with the precursor ions and product ions at identical mass settings), allowing unambiguous identification of the target analytes. Limits of detection for xenon and krypton were about 19 pmol/mL and 98 pmol/mL, respectively. Precision for both analytes was less than 15%. The method has good specificity as background analyte signals were not observed in negative equine plasma samples (n = 73). Loss of analytes under different storage temperatures has also been evaluated. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Communication Received from the Permanent Mission of the Netherlands regarding Certain Member States' Guidelines for the Export of Nuclear Material, Equipment and Technology; Communication recue de la mission permanente des Pays-Bas concernant les Directives de certains Etats Membres applicables a l'exportation de matieres, d'equipements et de technologie nucleaires

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-09-05

The Agency has received a Note Verbale from the Permanent Mission of the Kingdom of the Netherlands, dated 12 July 2011, in which it requests that the Agency circulate to all Member States a letter of 12 July 2011 from the Chairman of the Nuclear Suppliers Group, Ambassador Piet de Klerk, to the Director General, on behalf of the Governments of Argentina, Australia, Austria, Belarus, Belgium, Brazil, Bulgaria, Canada, China, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Japan, Kazakhstan, Republic of Korea, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, New Zealand, Norway, Poland, Portugal, Romania, Russian Federation, Slovakia, Slovenia, South Africa, Spain, Sweden, Switzerland, Turkey, Ukraine, the United Kingdom of Great Britain and Northern Ireland and the United States of America, providing further information on those Governments' Guidelines for Nuclear Transfers [French] L'Agence a recu une note verbale de la mission permanente du Royaume des Pays-Bas, en date du 12 juillet 2011, lui demandant de communiquer a tous les Etats Membres une lettre du 12 juillet 2011 du president du Groupe des fournisseurs nucleaires, l'ambassadeur Piet de Klerk, adressee au Directeur general au nom des gouvernements des Etats suivants : Afrique du Sud, Allemagne, Argentine, Australie, Autriche, Belarus, Belgique, Bresil, Bulgarie, Canada, Chine, Croatie, Chypre, Danemark, Espagne, Estonie, Etats-Unis d'Amerique, Federation de Russie, Finlande, France, Grece, Hongrie, Irlande, Islande, Italie, Japon, Kazakhstan, Lettonie, Lituanie, Luxembourg, Malte, Norvege, Nouvelle-Zelande, Pays-Bas, Pologne, Portugal, Republique de Coree, Republique tcheque, Roumanie, Royaume-Uni de Grande-Bretagne et d'Irlande du Nord, Slovaquie, Slovenie, Suede, Suisse, Turquie et Ukraineb. Cette lettre apporte des informations supplementaires sur les Directives de ces gouvernements applicables aux transferts nucleaires.

RESULTS FROM THE XENON100 EXPERIMENT

Directory of Open Access Journals (Sweden)

Rino Persiani

2013-12-01

Full Text Available The XENON program consists in operating and developing double-phase time projection chambers using liquid xenon as the target material. It aims to directly detect dark matter in the form of WIMPs via their elastic scattering off xenon nuclei. The current phase is XENON100, located at the Laboratori Nazionali del Gran Sasso (LNGS, with a 62 kg liquid xenon target. We present the 100.9 live days of data, acquired between January and June 2010, with no evidence of dark matter, as well as the new results of the last scientific run, with about 225 live days. The next phase, XENON1T, will increase the sensitivity by two orders of magnitude.

Latest results from XENON100 data

International Nuclear Information System (INIS)

Scotto Lavina, L.

2014-01-01

XENON100 is the current phase of the XENON dark matter program, which aims for the direct detection of WIMPs with liquid xenon time-projection chambers. We present the status of the experiment after 224.6 live days taken in 2011 and 2012 during which the detector successfully improved in terms of more calibration data, higher xenon purity, lower threshold and better background removal. The analysis has yielded no evidence for dark matter interactions. The status of the next generation XENON1T detector will be briefly described. The goal of XENON1T is to increase the fiducial volume by a factor 10 and reduce the background noise by a factor 100

Appropriate xenon-inhalation time in xenon-enhanced CT using the end-tidal gas-sampling method

Energy Technology Data Exchange (ETDEWEB)

Asada, Hideo; Furuhata, Shigeru; Onozuka, Satoshi; Uchida, Koichi; Fujii, Koji; Suga, Sadao; Kawase, Takeshi; Toya, Shigeo; Shiga, Hayao

1988-12-01

For the end-tidal gas-sampling method of xenon-enhanced CT (Xe-CT), the respective functional images of K, lambda, and the regional cerebral blood flow (rCBF) were studied and compared using the data at 7-, 10-, 15- and 25-minute inhalations. The most appropriate inhalation time of xenon gas was evaluated in 14 clinical cases. An end-tidal xenon curve which represents the arterial xenon concentration was monitored with a xenon analyzer; the xenon concentration was gradually increased to a level of 50% by using a xenon inhalator with a closed circuit to prevent the overestimation of the xenon concentration sampled from the mask. Serial CT scans were taken over a period of 25 minutes of inhalation. The functional images of K, lambda, and rCBF were calculated for serial CT scans for 7, 10, 15 and 25 minutes using Fick's equation. Those various images and absolute values were then compared. The rCBF value of a 15-minute inhalation was approximately 15% greater than that of 25 minutes, while the values of K, lambda, rCBF from a 15-minute inhalation were significantly correlated to those from 25 minutes. The regression line made it possible to estimate 25-minute inhalation values from those of 15 minutes. In imaging, the rCBF mapping of the 15-minute inhalation was found to be more reliable than that of 25 minutes. This study suggests that the minimal time of xenon inhalation is 15 minutes for the end-tidal gas-sampling method. A longer inhalation may be necessary for the estimation of rCBF in the low-flow area, such as the white matter or the pathological region.

Communication Received from Certain Member States Regarding Guidelines for Transfers of Nuclear-related Dual-use Equipment, Material, Software and Related Technology; Communication recue de certains Etats Membres concernant les directives applicables aux transferts d'equipements, de matieres et de logiciels a double usage dans le domaine nucleaire, ainsi que de technologies connexes

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-09-09

The Agency has received a Note Verbale from the Permanent Mission of Hungary, dated 14 June 2010, in which it requests that the Agency circulate to all Member States a letter of 7 May 2010 from the Chairman of the Nuclear Suppliers Group, Ambassador Ms. Gyorgyi Martin Zanathy, to the Director General, on behalf of the Governments of Argentina, Australia, Austria, Belarus, Belgium, Brazil, Bulgaria, Canada, China, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Japan, Kazakhstan, Republic of Korea, Latvia, Lithuania, Luxemburg, Malta, Netherlands, New Zealand, Norway, Poland, Portugal, Romania, Russian Federation, Slovakia, Slovenia, South Africa, Spain, Sweden, Switzerland, Turkey, Ukraine, the United Kingdom of Great Britain and Northern Ireland and the United States of America,1 providing further information on those Governments' Guidelines for Nuclear Transfers [French] L'Agence a recu une note verbale de la mission permanente de la Hongrie, en date du 14 juin 010, lui demandant de communiquer a tous les Etats Membres une lettre du 7 mai 2010 du president du Groupe des fournisseurs nucleaires, l'ambassadeur Gyorgyi Martin Zanathy, adressee au Directeur general au nom des gouvernements des Etats suivants : Afrique du Sud, Allemagne, Argentine, Australie, Autriche, Belarus, Belgique, Bresil, Bulgarie, Canada, Chine, Croatie, Chypre, Danemark, Espagne, Estonie, Etats-Unis d'Amerique, Federation de Russie, Finlande, France, Grece, Hongrie, Irlande, Islande, Italie, Japon, Kazakhstan, Lettonie, Lituanie, Luxembourg, Malte, Norvege, Nouvelle-Zelande, Pays-Bas, Pologne, Portugal, Republique de Coree, Republique tcheque, Roumanie, Royaume-Uni de Grande-Bretagne et d'Irlande du Nord, Slovaquie, Slovenie, Suede, Suisse, Turquie et Ukraine1. Cette lettre apporte des informations supplementaires sur les Directives de ces gouvernements applicables aux transferts nucleaires.

Topological signature in the NEXT high pressure xenon TPC

Science.gov (United States)

Ferrario, Paola; NEXT Collaboration

2017-09-01

The NEXT experiment aims to observe the neutrinoless double beta decay of 136Xe in a high-pressure xenon gas TPC using electroluminescence to amplify the signal from ionization. One of the main advantages of this technology is the possibility to use the topology of events with energies close to Qββ as an extra tool to reject background. In these proceedings we show with data from prototypes that an extra background rejection factor of 24.3 ± 1.4 (stat.)% can be achieved, while maintaining an efficiency of 66.7 ± 1.% for signal events. The performance expected in NEW, the next stage of the experiment, is to improve to 12.9% ± 0.6% background acceptance for 66.9% ± 0.6% signal efficiency.

Novel methods and applications of NMR and MRI. Low-power RF excitation and hyperpolarized Xenon-129

Energy Technology Data Exchange (ETDEWEB)

Amor, Nadia

2012-07-01

Since their discovery in the middle of the last century, Nuclear Magnetic Resonance (NMR) and Magnetic Resonance Imaging (MRI) have become an important and very versatile tool in industry, medicine, and basic research. The aim of this work is to explore possible improvements and new applications of NMR methods. First, a recently introduced excitation NMR pulse sequence, termed Frank sequence excitation, which allows for significant reduction of rf-excitation power, is systematically analyzed and compared to conventional NMR in detail. Furthermore, its feasibility for MRI is investigated and advantages as well as drawbacks in comparison to standard MRI are discussed. The second part focuses on new biomedical applications of hyperpolarized (HP) {sup 129}Xe which not only offers a signal enhancement of several orders of magnitude but also provides new contrast mechanisms. A setup for continuous dissolution of HP {sup 129}Xe gas into blood and other fluids is optimized and analyzed quantitatively by NMR and MRI. On the basis of these results, blood-dissolved HP {sup 129}Xe is used to investigate blood-gas dynamics, as well as the rheological behavior of blood.

Separation and purification of xenon

International Nuclear Information System (INIS)

Schlea, C.S.

1978-01-01

Xenon is separated from a mixture of xenon and krypton by extractive distillation using carbon tetrafluoride as the partitioning agent. Krypton is flushed out of the distillation column with CF 4 in the gaseous overhead stream while purified xenon is recovered from the liquid bottoms. The distillation is conducted at about atmospheric pressure or at subatmospheric pressure

129Xe NMR spectroscopy in microporous solids: The effect of bulk properties

International Nuclear Information System (INIS)

Ripmeester, John A.; Ratcliffe, Christopher I.

1993-01-01

In this contribution we point out a number of factors related to the bulk properties of microporous solids which must be taken into account in order first of all to obtain meaningful 129 Xe NMR spectral data, and secondly to interpret the data properly. This sensitivity to bulk properties is especially important for microporous solids where there is little or no barrier to xenon passage from inside the particle to the interparticle space. We examine the effect of particle size, powder bulk density and particle anisotropy, and also the effect of low thermal conductivity of low density powders

SCPRI Emergency Kit for Use in the Event of a Nuclear Accident; Le Dispositif d'Intervention Rapide du SCPRI en Cas d'Accident Nucleaire

Energy Technology Data Exchange (ETDEWEB)

Ervet, P.; Moroni, J. P.; Pellerin, P. [Service Central de Protection Contre les Rayonnements Ionisants, Ministere des Affaires Sociales, Le Vesinet (France)

1969-10-15

In the event of a nuclear accident necessitating implementation of the ORSEC radiation protection plan, the Service central de protection contre les rayonnements ionisants (Central Service for Protection against Ionizing Radiations), in conjunction with the Service national de la protection civile (National Civil Defence Service), has adopted the necessary measures for rapid evaluation of possible contamination as promptly as possible. With this aim in mind the Service has prepared emergency kits, which are permanently stored at airfields in the Paris region; these can be carried by aircraft together with two engineers from the Service, thereby enabling them to reach the site of the incident with the specialized equipment in a few hours at most. This paper describes the monitoring and sampling equipment as well as the conditions under which the kit is carried and used (it operates independently by having a built-in generating unit). It is basically designed to permit an initial assessment of the situation, to furnish local authorities with data on which to base decisions for the safety of the population, and to determine any additional measures that need to be adopted. (author) [French] Dans le cas d'un accident nucleaire impliquant la mise en application du plan ORSEC radiologique, en liaison avec le Service national de la protection civile, le Service central de protection contre les rayonnements ionisants a pris les dispositions necessaires pour faire une evaluation rapide, aussi preooce que possible, des contaminations eventuelles. Dans ce but, il a realise des cantines d'intervention qui sont deposees en permanence sur les aerodromes de la region parisienne, et peuvent etre embarquees par avion avec deux ingenieurs du service qui peuvent etre ainsi sur les lieux de l'incident, avec un materiel specialise, dans un delai qui n'excede pas quelques heures. Le memoire decrit le materiel de mesure et de prelevement, ainsi que les conditions de transport et d

Communications of 15 November 1999 Received from Member States Regarding the Export of Nuclear Material and of Certain Categories of Equipment and Other Material; Communications En Date Du 15 Novembre 1999 Recues D'Etats Membres Concernant L'Exportation De Matieres Nucleaires Et De Certaines Categories D'Equipements Et D'Autres Matieres

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-15

The Director General of the International Atomic Energy Agency has received letters of 17 October 1996 from the Resident Representatives of Argentina, Australia, Austria, Bulgaria, Canada, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Japan, Republic of Korea, the Netherlands, Norway, Poland, Portugal, Romania, the Russian Federation, the Slovak Republic, South Africa, Spain, Sweden, the United Kingdom, and the United States of America, concerning the export of nuclear material and of certain categories of equipment and other material [French] Le Directeur general de l'Agence internationale de l'energie atomique a recu des lettres datees du 15 novembre 1999 que les representants permanents des pays suivants lui ont adressees au sujet de l'exportation de matieres nucleaires et de certaines categories d'equipements et d'autres matieres : Afrique du Sud, Allemagne, Argentine, Australie, Autriche, Belgique, Bulgarie, Canada, Coree (Republique de), Danemark, Espagne, Etats-Unis d'Amerique, Finlande, France, Grece, Hongrie, Irlande, Italie, Japon, Luxembourg, Norvege, Pays-Bas, Pologne, Portugal, Republique slovaque, Republique tcheque, Roumanie, Royaume-Uni, Suede, Suisse, Turquie et Ukraine.

The origin of cholesterol in chyle demonstrated by nuclear indicator methods; Origines du cholesterol du chyle mises en evidence par la methode des indicateurs nucleaires

Energy Technology Data Exchange (ETDEWEB)

Vyas, M

1962-07-01

In order to obtain information about the mechanism of the intestinal absorption of cholesterol, rats having a lymphatic abdominal fistula are used. The animals receive either 4-{sup 14}C- cholesterol subcutaneously or orally, or the 1-{sup 14}C acetate. The study of the specific radio-activities of the cholesterol in chyle, in serum, in the lining, and in the intestinal contents makes it possible to define the roles played by the transfer cholesterol from the serum, by the cholesterol synthesised intestinally, and by the absorption cholesterol, in the formations of the lymph and of the chylomicrons. A new theory is proposed for the mechanism of cholesterol absorption. (author) [French] Pour obtenir des renseignements concernant le mecanisme de l'absorption intestinale du cholesterol, on utilise des rats porteurs d'une fistule lymphatique abdominale. Les animaux recoivent soit du cholesterol 4-{sup 14}C par voie sous-cutanee ou par voie orale, soit de l'acetate 1-{sup 14}C. L'etude des radioactivites specifiques du cholesterol du chyle, du serum, de la paroi et du contenu intestinal permet de preciser les roles joues par le cholesterol de transfert d'origine serique, par le cholesterol de synthese intestinale et par le cholesterol d'absorption, dans la formation de la lymphe et des chylomicrons. Une theorie nouvelle concernant le mecanisme de l'absorption du cholesterol est proposee. (auteur)

Study of thick, nuclear-compensated silicon detectors; Etude des detecteurs epais au silicium compense nucleairement

Energy Technology Data Exchange (ETDEWEB)

Le Coroller, Y. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-09-01

A study is made here, from the point of view of the realization and the performance, of thick nuclear-compensated silicon detectors. After recalling the need for compensation and reviewing the existing methods, the author describes in detail the controlled realization of thick detectors by nuclear compensation from the theoretical and experimental points of view. The practical precautions which should be observed are given: control of the homogeneity of the starting material, control of the evolution of the compensation, elimination of parasitic processes. The performances of the detectors obtained are then studied: electrical characteristics (current, life-time) on the one hand, detection and spectrometry of penetrating radiations on the other hand. The results show, that the compensated diodes having an effective thickness of two millimeters operate satisfactorily as detectors for applied voltages of about 500 volts. The resolutions observed are then about 2 per cent for mono-energetic electrons and about 4 per cent for the gamma; they can be improved by the use of a pre-amplifier of very low background noise. (author) [French] Les detecteurs epais au silicium compense nucleairement sont etudies ici du double point de vue realisation et performances. Apres un rappel sur la necessite de la compensation et les procedes existants, la realisation controlee des detecteurs epais par compensation nucleaire est decrite en detail sous l'aspect theorique et l'aspect experimental. On met en evidence les precautions a prendre dans la pratique: controle de l'homogeneite du materiau de base, controle de l'evolution de la compensation, elimination des processus parasites. On etudie ensuite les performances de detecteurs obtenus : caracteristiques electriques (courant, duree de vie) d'une part, d'autre part detection et spectrometrie des rayonnements penetrants. Les resultats montrent que les diodes compensees ayant une epaisseur utile de deux

Study of thick, nuclear-compensated silicon detectors; Etude des detecteurs epais au silicium compense nucleairement

Energy Technology Data Exchange (ETDEWEB)

Le Coroller, Y [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-09-01

A study is made here, from the point of view of the realization and the performance, of thick nuclear-compensated silicon detectors. After recalling the need for compensation and reviewing the existing methods, the author describes in detail the controlled realization of thick detectors by nuclear compensation from the theoretical and experimental points of view. The practical precautions which should be observed are given: control of the homogeneity of the starting material, control of the evolution of the compensation, elimination of parasitic processes. The performances of the detectors obtained are then studied: electrical characteristics (current, life-time) on the one hand, detection and spectrometry of penetrating radiations on the other hand. The results show, that the compensated diodes having an effective thickness of two millimeters operate satisfactorily as detectors for applied voltages of about 500 volts. The resolutions observed are then about 2 per cent for mono-energetic electrons and about 4 per cent for the gamma; they can be improved by the use of a pre-amplifier of very low background noise. (author) [French] Les detecteurs epais au silicium compense nucleairement sont etudies ici du double point de vue realisation et performances. Apres un rappel sur la necessite de la compensation et les procedes existants, la realisation controlee des detecteurs epais par compensation nucleaire est decrite en detail sous l'aspect theorique et l'aspect experimental. On met en evidence les precautions a prendre dans la pratique: controle de l'homogeneite du materiau de base, controle de l'evolution de la compensation, elimination des processus parasites. On etudie ensuite les performances de detecteurs obtenus : caracteristiques electriques (courant, duree de vie) d'une part, d'autre part detection et spectrometrie des rayonnements penetrants. Les resultats montrent que les diodes compensees ayant une epaisseur utile de deux millimetres fonctionnent

Prospects for the Use of Plutonium in Reactors; Prospective d'Utilisation du Plutonium dans les Reacteurs

Energy Technology Data Exchange (ETDEWEB)

Fossoul, E.; Haubert, P. [BELGONUCLEAIRE (Belgium); Hirschberg, D.; Morlet, E. [International Business Machines of Belgium, Bruxelles (Belgium)

1967-09-15

The introduction, at an increasing rate, of power reactors using slightly enriched uranium will inevitably lead to the production of considerable quantities of plutonium over the next decade. Fast reactors will not be capable of absorbing this material before 1980. The question thus arises of whether one should store the plutonium far future use in fast reactors, recycle it in existing thermal reactors, or try to sell it. The problem has been studied for an electric power generating system that does not foresee selling the plutonium produced by its reactors and does not buy plutonium outside, which enables a good approximation to be made and eliminates the major unknown quantity represented by the future market price of plutonium. Assuming within this system a programme that provides for the construction of power reactors of a given type and capacity at specific dates, the utilization of the plutonium produced can be optimized by linear programming techniques so as to minimize the discounted total cost of the power generated over a given period. A later stage consists in optimizing, by various techniques, not only the utilization but also the production of plutonium by appropriate selection of the power reactor types to be constructed. (author) [French] L'implantation, a un rythme croissant, de centrales nucleaires a uranium legerement enrichi entrainera la production ineluctable d'une quantite importante de plutonium au cours de la prochaine decennie. Les reacteurs a neutrons rapides ne seront capables d'absorber cette production qu'apres 1980. La question se pose donc de savoir s'il est preferable de stocker le plutonium en vue de son utilisation ulterieure dans les reacteurs a neutrons rapides plutot que de le recycler dans les reacteurs actuels a neutrons thermiques ou d'essayer de le vendre. Ce probleme a ete etudie dans le cadre d'un systeme de production d'energie electrique qui ne prevoirait pas la vente du plutonium produit par ses reacteurs nucleaires ni

Xenon preconditioning: molecular mechanisms and biological effects

Directory of Open Access Journals (Sweden)

Liu Wenwu

2013-01-01

Full Text Available Abstract Xenon is one of noble gases and has been recognized as an anesthetic for more than 50 years. Xenon possesses many of the characteristics of an ideal anesthetic, but it is not widely applied in clinical practice mainly because of its high cost. In recent years, numerous studies have demonstrated that xenon as an anesthetic can exert neuroprotective and cardioprotective effects in different models. Moreover, xenon has been applied in the preconditioning, and the neuroprotective and cardioprotective effects of xenon preconditioning have been investigated in a lot of studies in which some mechanisms related to these protections are proposed. In this review, we summarized these mechanisms and the biological effects of xenon preconditioning.

Method for internal conversion coefficients determination by means of a magnetic spectrometer. Application to 129Xe and 77Se

International Nuclear Information System (INIS)

Arqueros, F.; Campos, J.

1986-01-01

The method used for efficiency calibration of a magnetic electron spectrometer and its applications to conversion electron spectrometry is described. The present results point out that apparatus combining magnetic deflection and semiconductor detection have a nondecreasing interest in nuclear spectrometry for applications where good resolution and large background rejection are both necessary. The present apparatus can be employed with source of relatively low activity, (0.lμCi). The nuclides studied were 129 Xe and 77 Se resulting from 129 Cs and 77 Br decay. The parent nulcides were produced in ISOLDE on line isotope separator at CERN. The efficiency calibration method used for energies higher than 200 keV made use of the well known beta spectrum of 36 Cl. The calibration for low energies was made with Auger electron intensities and suitable conversion lines of 129 Xenon. Results for relative intensities of conversion electron lines and intense gamma lines of 129 Xe and 77 Se are given. From these measurements internal conversion coefficients for transitions of both nuclides were obtained. The results were in agreement with theoretical calculations. (author)

Feasibility, tolerability and safety of pediatric hyperpolarized {sup 129}Xe magnetic resonance imaging in healthy volunteers and children with cystic fibrosis

Energy Technology Data Exchange (ETDEWEB)

Walkup, Laura L.; Watters, Erin; Ruppert, Kai [Cincinnati Children' s Hospital Medical Center, Center for Pulmonary Imaging Research, Division of Pulmonary Medicine and Department of Radiology, Cincinnati, OH (United States); Thomen, Robert P.; Woods, Jason C. [Cincinnati Children' s Hospital Medical Center, Center for Pulmonary Imaging Research, Division of Pulmonary Medicine and Department of Radiology, Cincinnati, OH (United States); Washington University in St. Louis, Department of Physics, St. Louis, MO (United States); Akinyi, Teckla G.; Cleveland, Zackary I. [Cincinnati Children' s Hospital Medical Center, Center for Pulmonary Imaging Research, Division of Pulmonary Medicine and Department of Radiology, Cincinnati, OH (United States); University of Cincinnati, Biomedical Engineering Program, Cincinnati, OH (United States); Clancy, John P. [Cincinnati Children' s Hospital Medical Center, Division of Pulmonary Medicine, Cincinnati, OH (United States)

2016-11-15

Hyperpolarized {sup 129}Xe is a promising contrast agent for MRI of pediatric lung function, but its safety and tolerability in children have not been rigorously assessed. To assess the feasibility, safety and tolerability of hyperpolarized {sup 129}Xe gas as an inhaled contrast agent for pediatric pulmonary MRI in healthy control subjects and in children with cystic fibrosis. Seventeen healthy control subjects (ages 6-15 years, 11 boys) and 11 children with cystic fibrosis (ages 8-16 years, 4 boys) underwent {sup 129}Xe MRI, receiving up to three doses of {sup 129}Xe gas prepared by either a commercially available or a homebuilt {sup 129}Xe polarizer. Subject heart rate and SpO{sub 2} were monitored for 2 min post inhalation and compared to resting baseline values. Adverse events were reported via follow-up phone call at days 1 and 30 (range ±7 days) post-MRI. All children tolerated multiple doses of {sup 129}Xe, and no children withdrew from the study. Relative to baseline, most children who received a full dose of gas for imaging (10 of 12 controls and 8 of 11 children with cystic fibrosis) experienced a nadir in SpO{sub 2} (mean -6.0 ± standard deviation 7.2%, P≤0.001); however within 2 min post inhalation SpO{sub 2} values showed no significant difference from baseline (P=0.11). There was a slight elevation in heart rate (mean +6.6 ± 13.9 beats per minute [bpm], P=0.021), which returned from baseline within 2 min post inhalation (P=0.35). Brief side effects related to the anesthetic properties of xenon were mild and quickly resolved without intervention. No serious or severe adverse events were observed; in total, four minor adverse events (14.3%) were reported following {sup 129}Xe MRI, but all were deemed unrelated to the study. The feasibility, safety and tolerability of {sup 129}Xe MRI has been assessed in a small group of children as young as 6 years. SpO{sub 2} changes were consistent with the expected physiological effects of a short anoxic breath

Study of the tributyl phosphate - 30% dodecane solvent; Etude du solvant phosphate tributylique - 30 % dodecane

Energy Technology Data Exchange (ETDEWEB)

Leroy, P [Commissariat a l' Energie Atomique, Fontenay-aux-Roses. Centre d' Etudes Nucleaires, 92 (France)

1967-07-01

This study, originating mainly from a literature survey, gives the principal chemical and physical features of the tributyl-phosphate (TBP) agent diluted at 30 volumes per cent in dodecane. The mixture is a very commonly used extractant in nuclear fuel processing. In this paper, the main following points are reported: -) the components (TBP and diluents) -) the TBP-diluents systems (non-loaded), -) the TBP-diluents-water systems, -) TBP-diluents-water-nitric acid systems, and -) industrial solvents. (author) [French] Cette etude, d'origine bibliographique, regroupe les caracteristiques physico-chimiques essentielles du phosphate tributylique (TBP) dilue a 30% en volume dans du dodecane. Ce melange constitue un agent d'extraction tres utilise dans le traitement des combustibles nucleaires. Les principaux points traites sont les suivants: -) les constituants (TBP et diluants), -) les systemes TBP-diluants non charges, -) les systemes TBP-diluants-eau, -) les systemes TBP-diluants-eau-acide nitrique, et -) les solvants industriels. (auteur)

France's nuclear power programme; Le programme nucleaire francais

Energy Technology Data Exchange (ETDEWEB)

Cabanius, J [Electricite de France (EDF), 75 - Paris (France); Horowitz, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

-increasing importance, by using the country's resources of natural uranium, and later plutonium, to the best ends. (authors) [French] Les perspectives d'evolution de la consommation d'energie electrique francaise confirment l'aggravation du deficit des ressources energetiques metropolitaines. Les centrales nucleaires doivent permettre de diminuer ce deficit si un certain nombre d'incertitudes actuelles sont levees. Le premier programme presente par MM AILLERET et TARANGER a la Conference de Geneve en 1955 visait la mise en service pour 1965 de 850 MWe; il a ete consacre au developpement de la filiere uranium naturel - graphite - gaz et s'acheve avec la realisation d'EDF 3, premiere unite capable de 500 MWe engagee dans le monde. Avant de passer du stade des prototypes a celui des duplications, ELECTRICITE DE FRANCE a decide, en accord avec le COMMISSARIAT A L'ENERGIE ATOMIQUE, la realisation d'EDF 4 qui, en reprenant la partie reacteur d'EDF 3 ainsi que l'appareil de chargement et de dechargement, l'ensemble de controle et divers materiels, apporte une innovation importante en incorporant les echangeurs et les soufflantes a l'interieur du caisson en beton precontraint contenant le coeur. En meme temps, les etudes se poursuivent dans cette meme filiere et laissent entrevoir les possibilites d'utiliser un nouvel element combustible annulaire dont l'emploi ameliorerait notablement les performances d'EDF 5. Dans la filiere eau lourde, la realisation d'EL 4 a Brennilis par le COMMISSARIAT A L'ENERGIE ATOMIQUE et ELECTRICITE DE FRANCE se poursuit. Les etudes d'un reacteur de 500 MWe de cette filiere ont deja commence. Dans la filiere a eau pressurisee, la centrale de CHOOZ est realisee en association par ELECTRICITE DE FRANCE et les Producteurs Belges. Enfin, le COMMISSARIAT A L'ENERGIE ATOMIQUE poursuit a Cadarache la realisation du surgenerateur 'Rapsodie' et les etudes d'un reacteur de puissance plus important. Ainsi, les connaissances techniques et economiques acquises dans ces diverses

Cryogenics free production of hyperpolarized 129Xe and 83Kr for biomedical MRI applications

Science.gov (United States)

Hughes-Riley, Theodore; Six, Joseph S.; Lilburn, David M. L.; Stupic, Karl F.; Dorkes, Alan C.; Shaw, Dominick E.; Pavlovskaya, Galina E.; Meersmann, Thomas

2013-12-01

As an alternative to cryogenic gas handling, hyperpolarized (hp) gas mixtures were extracted directly from the spin exchange optical pumping (SEOP) process through expansion followed by compression to ambient pressure for biomedical MRI applications. The omission of cryogenic gas separation generally requires the usage of high xenon or krypton concentrations at low SEOP gas pressures to generate hp 129Xe or hp 83Kr with sufficient MR signal intensity for imaging applications. Two different extraction schemes for the hp gasses were explored with focus on the preservation of the nuclear spin polarization. It was found that an extraction scheme based on an inflatable, pressure controlled balloon is sufficient for hp 129Xe handling, while 83Kr can efficiently be extracted through a single cycle piston pump. The extraction methods were tested for ex vivo MRI applications with excised rat lungs. Precise mixing of the hp gases with oxygen, which may be of interest for potential in vivo applications, was accomplished during the extraction process using a piston pump. The 83Kr bulk gas phase T1 relaxation in the mixtures containing more than approximately 1% O2 was found to be slower than that of 129Xe in corresponding mixtures. The experimental setup also facilitated 129Xe T1 relaxation measurements as a function of O2 concentration within excised lungs.

Cryogenics free production of hyperpolarized 129Xe and 83Kr for biomedical MRI applications☆

Science.gov (United States)

Hughes-Riley, Theodore; Six, Joseph S.; Lilburn, David M.L.; Stupic, Karl F.; Dorkes, Alan C.; Shaw, Dominick E.; Pavlovskaya, Galina E.; Meersmann, Thomas

2013-01-01

As an alternative to cryogenic gas handling, hyperpolarized (hp) gas mixtures were extracted directly from the spin exchange optical pumping (SEOP) process through expansion followed by compression to ambient pressure for biomedical MRI applications. The omission of cryogenic gas separation generally requires the usage of high xenon or krypton concentrations at low SEOP gas pressures to generate hp 129Xe or hp 83Kr with sufficient MR signal intensity for imaging applications. Two different extraction schemes for the hp gasses were explored with focus on the preservation of the nuclear spin polarization. It was found that an extraction scheme based on an inflatable, pressure controlled balloon is sufficient for hp 129Xe handling, while 83Kr can efficiently be extracted through a single cycle piston pump. The extraction methods were tested for ex vivo MRI applications with excised rat lungs. Precise mixing of the hp gases with oxygen, which may be of interest for potential in vivo applications, was accomplished during the extraction process using a piston pump. The 83Kr bulk gas phase T1 relaxation in the mixtures containing more than approximately 1% O2 was found to be slower than that of 129Xe in corresponding mixtures. The experimental setup also facilitated 129Xe T1 relaxation measurements as a function of O2 concentration within excised lungs. PMID:24135800

Separation of zirconium and hafnium; Separation du zirconium et de l'hafnium

Energy Technology Data Exchange (ETDEWEB)

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

1959-07-01

This account is more chemical than metallurgical in character. The reason for this is that so-called 'nuclear metal' must fulfil standards of purity which only chemical processes can attain. This paper must therefore be considered as a preliminary study, from which the metallurgists can form an idea of the treatments leading to the production of the metal. (author) [French] Cet expose a un caractere chimique plutot que metallurgique. La raison en est que le metal dit 'nucleaire' a des exigences de purete que seuls des processus chimiques peuvent satisfaire. Il faut donc considerer cet expose comme un preliminaire, permettant de donner une idee aux metallurgistes des traitements qui aboutissent a l'elaboration du metal. (auteur)

Xenon lighting adjusted to plant requirements

Energy Technology Data Exchange (ETDEWEB)

Koefferlein, M.; Doehring, T.; Payer, H.D.; Seidlitz, H.K. [GSF-Forschungszentrum fuer Umwelt und Gesundheit, Oberschleissheim (Germany)

1994-12-31

The high luminous flux and spectral properties of xenon lamps would provide an ideal luminary for plant lighting if not excess IR radiation poses several problems for an application: the required filter systems reduce the irradiance at spectral regions of particular importance for plant development. Most of the economical drawbacks of xenon lamps are related to the difficult handling of that excess IR energy. Furthermore, the temporal variation of the xenon output depending on the oscillations of the applied AC voltage has to be considered for the plant development. However, xenon lamps outperform other lighting systems with respect to spectral stability, immediate response, and maximum luminance. Therefore, despite considerable competition by other lighting techniques, xenon lamps provide a very useful tool for special purposes. In plant lighting however, they seem to play a less important role as other lamp and lighting developments can meet these particular requirements at lower costs.

Feasibility, tolerability and safety of pediatric hyperpolarized "1"2"9Xe magnetic resonance imaging in healthy volunteers and children with cystic fibrosis

International Nuclear Information System (INIS)

Walkup, Laura L.; Watters, Erin; Ruppert, Kai; Thomen, Robert P.; Woods, Jason C.; Akinyi, Teckla G.; Cleveland, Zackary I.; Clancy, John P.

2016-01-01

Hyperpolarized "1"2"9Xe is a promising contrast agent for MRI of pediatric lung function, but its safety and tolerability in children have not been rigorously assessed. To assess the feasibility, safety and tolerability of hyperpolarized "1"2"9Xe gas as an inhaled contrast agent for pediatric pulmonary MRI in healthy control subjects and in children with cystic fibrosis. Seventeen healthy control subjects (ages 6-15 years, 11 boys) and 11 children with cystic fibrosis (ages 8-16 years, 4 boys) underwent "1"2"9Xe MRI, receiving up to three doses of "1"2"9Xe gas prepared by either a commercially available or a homebuilt "1"2"9Xe polarizer. Subject heart rate and SpO_2 were monitored for 2 min post inhalation and compared to resting baseline values. Adverse events were reported via follow-up phone call at days 1 and 30 (range ±7 days) post-MRI. All children tolerated multiple doses of "1"2"9Xe, and no children withdrew from the study. Relative to baseline, most children who received a full dose of gas for imaging (10 of 12 controls and 8 of 11 children with cystic fibrosis) experienced a nadir in SpO_2 (mean -6.0 ± standard deviation 7.2%, P≤0.001); however within 2 min post inhalation SpO_2 values showed no significant difference from baseline (P=0.11). There was a slight elevation in heart rate (mean +6.6 ± 13.9 beats per minute [bpm], P=0.021), which returned from baseline within 2 min post inhalation (P=0.35). Brief side effects related to the anesthetic properties of xenon were mild and quickly resolved without intervention. No serious or severe adverse events were observed; in total, four minor adverse events (14.3%) were reported following "1"2"9Xe MRI, but all were deemed unrelated to the study. The feasibility, safety and tolerability of "1"2"9Xe MRI has been assessed in a small group of children as young as 6 years. SpO_2 changes were consistent with the expected physiological effects of a short anoxic breath-hold, and other mild side effects were

Xenon changes under power-burst conditions

International Nuclear Information System (INIS)

Diamond, D.J.

1983-01-01

Under ordinary operating conditions the xenon concentration in a reactor core can change significantly in times on the order of hours. Core transients of safety significance are much more rapid and hence calculations are done with xenon concentration held constant. However, in certain transients (such as reactivity initiated accidents) there is a very large power surge and the question arises as to whether under these circumstances the xenon concentration could change. This would be particularly important if the xenon were reduced thereby tending to make the accident autocatalytic. The objective of the present study is to quantify this effect to see if it could be important

Theoretical Study On The Interaction Between Xenon And Positive Silver Clusters In Gas Phase And On The (001) Chabazite Surface

International Nuclear Information System (INIS)

Hunter, D.

2009-01-01

A systematic study on the adsorption of xenon on silver clusters in the gas phase and on the (001) surface of silver-exchanged chabazite is reported. Density functional theory at the B3LYP level with the cluster model was employed. The results indicate that the dominant part of the binding is the σ donation, which is the charge transfer from the 5p orbital of Xe to the 5s orbital of Ag and is not the previously suggested d π -d π back-donation. A correlation between the binding energy and the degree of σ donation is found. Xenon was found to bind strongly to silver cluster cations and not to neutral ones. The binding strength decreases as the cluster size increases for both cases, clusters in the gas-phase and on the chabazite surface. The Ag + cation is the strongest binding site for xenon both in gas phase and on the chabazite surface with the binding energies of 73.9 and 14.5 kJ/mol, respectively. The results also suggest that the smaller silver clusters contribute to the negative chemical shifts observed in the 129 Xe NMR spectra in experiments.

Control aid for xenon vibration in reactor

International Nuclear Information System (INIS)

Kanekawa, Takashi.

1990-01-01

In the present invention, the control operation for suppressing xenon vibrations in a reactor is aided for saving forecasting analysis and operator's skills. That is, parameters to be controlled for the suppression of xenon vibrations are power distribution, iodine distribution and xenon distribution. But what can be observed by operaters by the conventional fast overtone method is only the output distribution. In the present invention, the output level of the reactor core is always observed. Then, mathematical processings are conducted for the iodine distribution, the xenon distribution and the power distribution in the reactor core based on the histeresis of the parameters obtained by the measurement using physical constants and reactor design data. The xenon vibration control is aided by displaying the change with time of the distortion in axial direction. Accordingly, operators can always recognize the axial distortion of the power distribution, the iodine distribution and the xenon distribution. (I.S.)

Liquid xenon detector engineering

International Nuclear Information System (INIS)

Chen, E.; Chen, M.; Gaudreau, M.P.J.; Montgomery, D.B.; Pelly, J.D.; Shotkin, S.; Sullivan, J.D.; Sumorok, K.; Yan, X.; Zhang, X.; Lebedenko, V.

1991-01-01

The design, engineering constraints and R and D status of a 15 m 3 precision liquid xenon, electromagnetic calorimeter for the Superconducting Super Collider are discussed in this paper. Several prototype liquid xenon detectors have been built, and preliminary results are described. The design of a conical 7 cell by 7 cell detector capable of measuring fully contained high energy electron showers is described in detail

Xenon-based Penning mixtures for proportional counters

International Nuclear Information System (INIS)

Ramsey, B.D.; Agrawal, P.C.; National Aeronautics and Space Administration, Huntsville, AL

1989-01-01

The choice of quench gas can have a significant effect on the gas gain and energy resolution of gas-filed proportional counters. Details are given on the performance obtained with a variety of quench additives of varying ionization potentials for use in xenon-filled systems. It is confirmed that optimum performance is obtained when the ionization potential is closely matched to the first metastable level of xenon (8.3 eV) as is the case with xenon + trimethylamine and xenon + dimethylamine. For these mixtures the Penning effect is at its strongest. (orig.)

Investigation of DOTA-Metal Chelation Effects on the Chemical Shift of ¹²⁹ Xe

Energy Technology Data Exchange (ETDEWEB)

Jeong, K; Slack, CC; Vassiliou, CC; Dao, P; Gomes, MD; Kennedy, DJ; Truxal, AE; Sperling, LJ; Francis, MB; Wemmer, DE; Pines, A

2015-09-17

Recent work has shown that xenon chemical shifts in cryptophane-cage sensors are affected when tethered chelators bind to metals. Here in this paper, we explore the xenon shifts in response to a wide range of metal ions binding to diastereomeric forms of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) linked to cryptophane-A. The shifts induced by the binding of Ca²⁺, Cu²⁺, Ce³⁺, Zn²⁺, Cd²⁺, Ni²⁺, Co²⁺, Cr²⁺, Fe³⁺, and Hg²⁺ are distinct. In addition, the different responses of the diastereomers for the same metal ion indicate that shifts are affected by partial folding with a correlation between the expected coordination number of the metal in the DOTA complex and the chemical shift of ¹²⁹Xe. Lastly, these sensors may be used to detect and quantify many important metal ions, and a better understanding of the basis for the induced shifts could enhance future designs.

Contamination of North Sea and Baltic Sea with long-living iodine-129 and other anthropogenic radionuclides; Kontamination von Nord- und Ostsee mit langlebigem Iod-129 und anderen anthropogenen Radionukliden

Energy Technology Data Exchange (ETDEWEB)

Tosch, Luebbert

2010-10-12

The radionuclide iodine-129 (T{sub 1/2} = 15.7 Ma) is produced in nature by spontaneous fission of uranium-238 and by cosmic ray induced spallation of xenon. Due to the military and civil use of neutron-induced fission of uranium-235 and plutonium-239 a huge amount of iodine-129 has been released into the environment. The main sources of anthropogenic {sup 129}I are the reprocessing plants in La Hague (France) near the English Channel and in Sellafield (UK) close to the Irish Sea. The natural equilibrium {sup 129}I/{sup 127}I-isotopic ratios are estimated to 1.5 . 10{sup -12} for the marine hydrosphere and to 3.0 . 10{sup -13} for the terrestrial biosphere respectively. Due to the emissions of anthropogenic iodine-129 the {sup 129}I/{sup 127}I-isotopic ratios have been increased in all compartments of the environment. Surface water samples taken from the English Channel, the North Sea, the Baltic Sea, the Irish Sea, and the North Atlantic give information about anthropogenic changes. Iodine turns out to be a conservative tracer in seawater. The iodine-127 concentrations in seawater except for coastal areas are rather constant (40.7 ± 6.2 ng/g). The observed {sup 129}I/{sup 127}I-isotopic ratios range between 10{sup -10} and more than 10{sup -6}. The variation of the {sup 129}I/{sup 127}I-isotopic ratios is caused by the admixture of anthropogenic iodine-129. Water samples taken far away from the reprocessing plants show the lowest isotopic ratios. The highest {sup 129}I/{sup 127}I-isotopic ratios are found near the reprocessing plants. The transport of {sup 129}I from La Hague has a rather clear pattern. It can be observed along the coasts of France, Belgium, the Netherlands, Germany and Denmark. The iodine-129 emissions from Sellafield can be followed northbound along the Scottish coast. The results of other anthropogenic radionuclides are used for discussing transport processes in the North Sea and the Irish Sea. Large areas in the North Sea are characterised by

Separation of the fission product noble gases krypton and xenon from dissolver off-gas in reprocessing HTGR-fuel

Energy Technology Data Exchange (ETDEWEB)

Bohnenstingl, J.; Djoa, S. H.; Laser, M.; Mastera, S.; Merz, E.; Morschl, P.

1976-04-15

This paper describes a process developed for the retainment and separation of volatile (³H, ^{129 +131}I) and gaseous (⁸⁵Kr, Xe) fission products from the off-gas produced during dissolution of HTGR-fuel. To prevent unnecessary dilution of liberated noble gases by surrounding atmosphere, a helium purge-gas cycle is applied to enable a coarse fractionating of krypton and xenon by cold-trapping at about 80 deg K after precleaning the gas stream. The process consists of the following steps: deposition of droplets and solid aerosols; chemisorption of iodine on silver impregnated silica gel; catalytic removal of nitrogen oxides and oxygen; drying of the process gas stream; final filtering of abraded solids; deposition of xenon in solid form at 80 deg K and low subpressure; deposition of krypton in solid form at 80 deg K after compression to about 6 bar; decontamination of ⁸⁵krypton-containing xenon by batch distillation for eventual industrial utilization; and removal of nitrogen and argon enrichment during continuous operation in the purge-gas stream by inleaking air with charcoal. A continuously operating dissolver vessel, closed to the surrounding atmosphere, yields a very high content of noble gases, e.g., 0.35 vol % krypton and 2.0 vol % xenon. The presented off-gas treatment unit is operated in cold runs with 1/3 of the full capacity and can treat about 1 m³ STP/h helium, corresponding to a quantity of about 10,000 MW(e) HTGR-fuel reprocessing plant.

Separation of the fission product noble gases krypton and xenon from dissolver off-gas in reprocessing HTGR-fuel

International Nuclear Information System (INIS)

Bohnenstingl, J.; Djoa, S.H.; Laser, M.; Mastera, S.; Merz, E.; Morschl, P.

1976-01-01

This paper describes a process developed for the retainment and separation of volatile ( 3 H, 129+131 I) and gaseous ( 85 Kr, Xe) fission products from the off-gas produced during dissolution of HTGR-fuel. To prevent unnecessary dilution of liberated noble gases by surrounding atmosphere, a helium purge-gas cycle is applied to enable a coarse fractionating of krypton and xenon by cold-trapping at about 80 0 K after precleaning the gas stream. The process consists of the following steps: deposition of droplets and solid aerosols; chemisorption of iodine on silver impregnated silica gel; catalytic removal of nitrogen oxides and oxygen; drying of the process gas stream; final filtering of abraded solids; deposition of xenon in solid form at 80 0 K and low subpressure; deposition of krypton in solid form at 80 0 K after compression to about 6 bar; decontamination of 85 Kr-containing xenon by batch distillation for eventual industrial utilization; and removal of nitrogen and argon enrichment during continuous operation in the purge-gas stream by inleaking air with charcoal. A continuously operating dissolver vessel, closed to the surrounding atmosphere, yields a very high content of noble gases, i.e., 0.35 vol % krypton and 2.0 vol % xenon. The presented off-gas treatment unit is operated in cold runs with 1 / 3 of the full capacity and can treat about 1 m 3 STP/h helium, corresponding to a quantity of about 10,000 MW/sub e/ HTGR-fuel reprocessing plant

Solubility of xenon in liquid sodium

International Nuclear Information System (INIS)

Veleckis, E.; Cafasso, F.A.; Feder, H.M.

1976-01-01

The solubility of xenon in liquid sodium was measured as a function of pressure (2-8 atm) and temperature (350-600 0 C). Henry's law was obeyed with the value of the Henry's law constant, K/sub H/ = N/sub Xe//P, ranging from 1.38 x 10 -10 atm -1 at 350C, to 1.59 x 10 -8 atm -1 at 600 0 C where N/sub Xe/ and P are the atom fraction and the partial pressure of xenon, respectively. The temperature dependence of solubility may be represented by log 10 lambda = (0.663 +- 0.01) - (4500 +- 73) T -1 , where lambda is the Ostwald coefficient (the volume of xenon dissolved per unit volume of sodium at the temperature of the experiment). The heat of solution of xenon in sodium was 20.6 +- 0.7 kcal/mole, where the standard state of xenon is defined as that of 1 mole of an ideal gas, confined to a volume equal to the molar volume of sodium

The design and construction of a nuclear free-precession magnetometer; Etude et realisation d'un magnetometre a precession libre nucleaire

Energy Technology Data Exchange (ETDEWEB)

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

1960-10-15

After presenting the advantages of nuclear magnetic resonance with respect to electromagnetic processes, as far as the measurement of the earths' magnetic field is concerned, we deal with the macroscopic theory for the Bloch model and analyse Packard and Varions' experiment. The development of a particular absolute free-precession magnetometer is studied, and the conditions are determined for obtaining a maximum amplitude signal as a function of the geometrical form of the detector coil, of the method of cut-off, and of the coupling between various parts of the system. After having described in detail the technology of amplifiers, we consider the problem of the measurement of the frequency of precession for which an original solution, of analogy form, is proposed and discussed. Complete plans of the equipment are given in an appendix. (author) [French] Apres avoir presente les avantages de la resonance magnetique nucleaire relativement aux procedes electromagnetiques, en ce qui concerne la mesure du champ magnetique terrestre, on traite de la theorie macroscopique dans le modele de Bloch et analyse l'experience de Packard et Varian. On etudie une realisation particuliere d'un magnetometre absolu a precession libre et determine les conditions d'obtention d'un signal d'amplitude maximale en fonction de la forme geometrique du bobinage detecteur, de la methode de coupure, et du couplage entre les differents elements du montage. Apres avoir decrit en detail la technologie des amplificateurs, on aborde le probleme de la mesure de la frequence de precession, pour laquelle une solution originale, sous forme analogique, est proposee et discutee. En annexe est joint un dossier complet des plans de la realisation. (auteur)

Xenon recovery from molybdenum-99 production

International Nuclear Information System (INIS)

Jubin, R.T.; Paviet, P.D.; Bresee, J.C.

2016-01-01

The U.S. Department of Energy Office of Nuclear Energy (DOE-NE) sponsors research and development on the recycle of used commercial nuclear fuel as an option for future nuclear fuel cycles that offers increased use of uranium and thorium resources and a possible reduction in the overall cost of nuclear waste management. The two alternatives, direct disposal of used fuel and fuel recycle, are broadly referred to as open and closed fuel cycles. One requirement of a closed fuel cycle is the safe management of radioactive off-gases, which includes 14 C, radioiodine and the noble gases, including radio-xenon. The longest lived relevant radio-xenon isotope is 127 Xe; with a half-life of just 36.35 days it is feasible to trap and hold the radio-xenon to allow for decay to safe environmental levels. However, the very weak chemical bonds of noble gases, in this case xenon, make them difficult to trap, which led to an extensive DOE-NE study of noble gas adsorption on various molecular sieves as an alternative to costly cryogenics processes. Preliminary results indicate that xenon adsorption at near room temperature on molecular sieves, both synthetic and natural, may have both cost and efficiency advantages over cryogenic processes. These results appear to have direct application in helping achieve the United Nations Security Council goal of reducing xenon emissions from medical isotope producers

The XENON1T dark matter experiment

Science.gov (United States)

Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Amaro, F. D.; Anthony, M.; Antunes, B.; Arneodo, F.; Balata, M.; Barrow, P.; Baudis, L.; Bauermeister, B.; Benabderrahmane, M. L.; Berger, T.; Breskin, A.; Breur, P. A.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Bütikofer, L.; Calvén, J.; Cardoso, J. M. R.; Cervantes, M.; Chiarini, A.; Cichon, D.; Coderre, D.; Colijn, A. P.; Conrad, J.; Corrieri, R.; Cussonneau, J. P.; Decowski, M. P.; de Perio, P.; Gangi, P. Di; Giovanni, A. Di; Diglio, S.; Disdier, J.-M.; Doets, M.; Duchovni, E.; Eurin, G.; Fei, J.; Ferella, A. D.; Fieguth, A.; Franco, D.; Front, D.; Fulgione, W.; Rosso, A. Gallo; Galloway, M.; Gao, F.; Garbini, M.; Geis, C.; Giboni, K.-L.; Goetzke, L. W.; Grandi, L.; Greene, Z.; Grignon, C.; Hasterok, C.; Hogenbirk, E.; Huhmann, C.; Itay, R.; James, A.; Kaminsky, B.; Kazama, S.; Kessler, G.; Kish, A.; Landsman, H.; Lang, R. F.; Lellouch, D.; Levinson, L.; Lin, Q.; Lindemann, S.; Lindner, M.; Lombardi, F.; Lopes, J. A. M.; Maier, R.; Manfredini, A.; Maris, I.; Undagoitia, T. Marrodán; Masbou, J.; Massoli, F. V.; Masson, D.; Mayani, D.; Messina, M.; Micheneau, K.; Molinario, A.; Morå, K.; Murra, M.; Naganoma, J.; Ni, K.; Oberlack, U.; Orlandi, D.; Othegraven, R.; Pakarha, P.; Parlati, S.; Pelssers, B.; Persiani, R.; Piastra, F.; Pienaar, J.; Pizzella, V.; Piro, M.-C.; Plante, G.; Priel, N.; García, D. Ramírez; Rauch, L.; Reichard, S.; Reuter, C.; Rizzo, A.; Rosendahl, S.; Rupp, N.; Santos, J. M. F. dos; Saldanha, R.; Sartorelli, G.; Scheibelhut, M.; Schindler, S.; Schreiner, J.; Schumann, M.; Lavina, L. Scotto; Selvi, M.; Shagin, P.; Shockley, E.; Silva, M.; Simgen, H.; Sivers, M. v.; Stern, M.; Stein, A.; Tatananni, D.; Tatananni, L.; Thers, D.; Tiseni, A.; Trinchero, G.; Tunnell, C.; Upole, N.; Vargas, M.; Wack, O.; Walet, R.; Wang, H.; Wang, Z.; Wei, Y.; Weinheimer, C.; Wittweg, C.; Wulf, J.; Ye, J.; Zhang, Y.

2017-12-01

The XENON1T experiment at the Laboratori Nazionali del Gran Sasso (LNGS) is the first WIMP dark matter detector operating with a liquid xenon target mass above the ton-scale. Out of its 3.2 t liquid xenon inventory, 2.0 t constitute the active target of the dual-phase time projection chamber. The scintillation and ionization signals from particle interactions are detected with low-background photomultipliers. This article describes the XENON1T instrument and its subsystems as well as strategies to achieve an unprecedented low background level. First results on the detector response and the performance of the subsystems are also presented.

The XENON1T dark matter experiment

International Nuclear Information System (INIS)

Aprile, E.; Anthony, M.; De Perio, P.; Gao, F.; Giboni, K.L.; Goetzke, L.W.; Greene, Z.; Lin, Q.; Plante, G.; Rizzo, A.; Stern, M.; Tatananni, D.; Zhang, Y.; Aalbers, J.; Breur, P.A.; Brown, A.; Colijn, A.P.; Decowski, M.P.; Doets, M.; Hogenbirk, E.; Tiseni, A.; Walet, R.; Agostini, F.; Alfonsi, M.; Geis, C.; Grignon, C.; Oberlack, U.; Othegraven, R.; Scheibelhut, M.; Schindler, S.; Amaro, F.D.; Antunes, B.; Cardoso, J.M.R.; Lopes, J.A.M.; Santos, J.M.F. dos; Silva, M.; Arneodo, F.; Benabderrahmane, M.L.; Di Giovanni, A.; Maris, I.; Balata, M.; Bruno, G.; Corrieri, R.; Disdier, J.M.; Rosso, A.G.; Molinario, A.; Orlandi, D.; Parlati, S.; Tatananni, L.; Wang, Z.; Barrow, P.; Baudis, L.; Franco, D.; Galloway, M.; James, A.; Kazama, S.; Kessler, G.; Kish, A.; Maier, R.; Mayani, D.; Pakarha, P.; Piastra, F.; Wulf, J.; Bauermeister, B.; Calven, J.; Conrad, J.; Ferella, A.D.; Moraa, K.; Pelssers, B.; Berger, T.; Brown, E.; Piro, M.C.; Breskin, A.; Budnik, R.; Duchovni, E.; Front, D.; Itay, R.; Landsman, H.; Lellouch, D.; Levinson, L.; Manfredini, A.; Priel, N.; Bruenner, S.; Cichon, D.; Eurin, G.; Hasterok, C.; Lindner, M.; Undagoitia, T.M.; Pizzella, V.; Rauch, L.; Rupp, N.; Schreiner, J.; Simgen, H.; Wack, O.; Buetikofer, L.; Coderre, D.; Kaminsky, B.; Schumann, M.; Sivers, M. von; Chiarini, A.; Di Gangi, P.; Garbini, M.; Massoli, F.V.; Sartorelli, G.; Selvi, M.; Cussonneau, J.P.; Diglio, S.; Masbou, J.; Micheneau, K.; Persiani, R.; Thers, D.; Fei, J.; Lombardi, F.; Ni, K.; Ye, J.; Fieguth, A.; Huhmann, C.; Murra, M.; Rosendahl, S.; Vargas, M.; Weinheimer, C.; Wittweg, C.; Fulgione, W.; Grandi, L.; Saldanha, R.; Shockley, E.; Tunnell, C.; Upole, N.; Lindemann, S.; Messina, M.; Naganoma, J.; Shagin, P.; Pienaar, J.; Garcia, D.R.; Reichard, S.; Lavina, L.S.; Stein, A.; Wang, H.; Trinchero, G.; Wei, Y.

2017-01-01

The XENON1T experiment at the Laboratori Nazionali del Gran Sasso (LNGS) is the first WIMP dark matter detector operating with a liquid xenon target mass above the ton-scale. Out of its 3.2 t liquid xenon inventory, 2.0 t constitute the active target of the dual-phase time projection chamber. The scintillation and ionization signals from particle interactions are detected with low-background photomultipliers. This article describes the XENON1T instrument and its subsystems as well as strategies to achieve an unprecedented low background level. First results on the detector response and the performance of the subsystems are also presented. (orig.)

The XENON1T dark matter experiment

Energy Technology Data Exchange (ETDEWEB)

Aprile, E.; Anthony, M.; De Perio, P.; Gao, F.; Giboni, K.L.; Goetzke, L.W.; Greene, Z.; Lin, Q.; Plante, G.; Rizzo, A.; Stern, M.; Tatananni, D.; Zhang, Y. [Columbia University, Physics Department, New York, NY (United States); Aalbers, J.; Breur, P.A.; Brown, A.; Colijn, A.P.; Decowski, M.P.; Doets, M.; Hogenbirk, E.; Tiseni, A.; Walet, R. [Nikhef and the University of Amsterdam, Amsterdam (Netherlands); Agostini, F. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Gran Sasso Science Institute, L' Aquila (Italy); University of Bologna, Department of Physics and Astrophysics (Italy); INFN-Bologna (Italy); Alfonsi, M.; Geis, C.; Grignon, C.; Oberlack, U.; Othegraven, R.; Scheibelhut, M.; Schindler, S. [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Amaro, F.D.; Antunes, B.; Cardoso, J.M.R.; Lopes, J.A.M.; Santos, J.M.F. dos; Silva, M. [University of Coimbra, LIBPhys, Department of Physics, Coimbra (Portugal); Arneodo, F.; Benabderrahmane, M.L.; Di Giovanni, A.; Maris, I. [New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Balata, M.; Bruno, G.; Corrieri, R.; Disdier, J.M.; Rosso, A.G.; Molinario, A.; Orlandi, D.; Parlati, S.; Tatananni, L.; Wang, Z. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Gran Sasso Science Institute, L' Aquila (Italy); Barrow, P.; Baudis, L.; Franco, D.; Galloway, M.; James, A.; Kazama, S.; Kessler, G.; Kish, A.; Maier, R.; Mayani, D.; Pakarha, P.; Piastra, F.; Wulf, J. [University of Zurich, Physik Institut, Zurich (Switzerland); Bauermeister, B.; Calven, J.; Conrad, J.; Ferella, A.D.; Moraa, K.; Pelssers, B. [Stockholm University, AlbaNova, Oskar Klein Centre, Department of Physics, Stockholm (Sweden); Berger, T.; Brown, E.; Piro, M.C. [Rensselaer Polytechnic Institute, Department of Physics, Applied Physics and Astronomy, Troy, NY (United States); Breskin, A.; Budnik, R.; Duchovni, E.; Front, D.; Itay, R.; Landsman, H.; Lellouch, D.; Levinson, L.; Manfredini, A.; Priel, N. [Weizmann Institute of Science, Department of Particle Physics and Astrophysics, Rehovot (Israel); Bruenner, S.; Cichon, D.; Eurin, G.; Hasterok, C.; Lindner, M.; Undagoitia, T.M.; Pizzella, V.; Rauch, L.; Rupp, N.; Schreiner, J.; Simgen, H.; Wack, O. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Buetikofer, L.; Coderre, D.; Kaminsky, B.; Schumann, M. [Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Sivers, M. von [Freiburg Univ. (Germany). Physikalisches Inst.; Bern Univ. (Switzerland). Albert Einstein Center for Fundamental Physics; Cervantes, M.; Lang, R.F.; Masson, D.; Reuter, C. [Purdue University, Department of Physics and Astronomy, West Lafayette, IN (United States); Chiarini, A.; Di Gangi, P.; Garbini, M.; Massoli, F.V.; Sartorelli, G.; Selvi, M. [University of Bologna, Department of Physics and Astrophysics, Bologna (Italy); INFN-Bologna (Italy); Cussonneau, J.P.; Diglio, S.; Masbou, J.; Micheneau, K.; Persiani, R.; Thers, D. [CNRS/IN2P3, Universite de Nantes, SUBATECH, IMT Atlantique, Nantes (France); Fei, J.; Lombardi, F.; Ni, K.; Ye, J. [University of California, Department of Physics, San Diego, CA (United States); Fieguth, A.; Huhmann, C.; Murra, M.; Rosendahl, S.; Vargas, M.; Weinheimer, C.; Wittweg, C. [Westfaelische Wilhelms-Universitaet Muenster, Institut fuer Kernphysik, Muenster (Germany); Fulgione, W. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Gran Sasso Science Institute, L' Aquila (Italy); INFN-Torino (Italy); Osservatorio Astrofisico di Torino, Turin (Italy); Grandi, L.; Saldanha, R.; Shockley, E.; Tunnell, C.; Upole, N. [University of Chicago, Department of Physics and Kavli Institute of Cosmological Physics, Chicago, IL (United States); Lindemann, S. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Messina, M. [Columbia University, Physics Department, New York, NY (United States); New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Naganoma, J.; Shagin, P. [Rice University, Department of Physics and Astronomy, Houston, TX (United States); Pienaar, J. [Purdue University, Department of Physics and Astronomy, West Lafayette, IN (United States); University of Chicago, Department of Physics and Kavli Institute of Cosmological Physics, Chicago, IL (United States); Garcia, D.R. [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Reichard, S. [University of Zurich, Physik Institut, Zurich (Switzerland); Purdue University, Department of Physics and Astronomy, West Lafayette, IN (United States); Lavina, L.S. [Universite Pierre et Marie Curie, Universite Paris Diderot, CNRS/IN2P3, LPNHE, Paris (France); Stein, A.; Wang, H. [University of California, Physics and Astronomy Department, Los Angeles, CA (United States); Trinchero, G. [INFN-Torino (Italy); Osservatorio Astrofisico di Torino, Turin (Italy); Wei, Y. [University of Zurich, Physik Institut, Zurich (Switzerland); University of California, Department of Physics, San Diego, CA (United States); Collaboration: XENON Collaboration

2017-12-15

The XENON1T experiment at the Laboratori Nazionali del Gran Sasso (LNGS) is the first WIMP dark matter detector operating with a liquid xenon target mass above the ton-scale. Out of its 3.2 t liquid xenon inventory, 2.0 t constitute the active target of the dual-phase time projection chamber. The scintillation and ionization signals from particle interactions are detected with low-background photomultipliers. This article describes the XENON1T instrument and its subsystems as well as strategies to achieve an unprecedented low background level. First results on the detector response and the performance of the subsystems are also presented. (orig.)

Xenon recovery from molybdenum-99 production

Energy Technology Data Exchange (ETDEWEB)

Jubin, R.T. [Oak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN, 37931 (United States); Paviet, P.D.; Bresee, J.C. [U.S. Department of Energy,1000 Independence Ave, S.W., Washington DC, 20585-1290 (United States)

2016-07-01

The U.S. Department of Energy Office of Nuclear Energy (DOE-NE) sponsors research and development on the recycle of used commercial nuclear fuel as an option for future nuclear fuel cycles that offers increased use of uranium and thorium resources and a possible reduction in the overall cost of nuclear waste management. The two alternatives, direct disposal of used fuel and fuel recycle, are broadly referred to as open and closed fuel cycles. One requirement of a closed fuel cycle is the safe management of radioactive off-gases, which includes {sup 14}C, radioiodine and the noble gases, including radio-xenon. The longest lived relevant radio-xenon isotope is {sup 127}Xe; with a half-life of just 36.35 days it is feasible to trap and hold the radio-xenon to allow for decay to safe environmental levels. However, the very weak chemical bonds of noble gases, in this case xenon, make them difficult to trap, which led to an extensive DOE-NE study of noble gas adsorption on various molecular sieves as an alternative to costly cryogenics processes. Preliminary results indicate that xenon adsorption at near room temperature on molecular sieves, both synthetic and natural, may have both cost and efficiency advantages over cryogenic processes. These results appear to have direct application in helping achieve the United Nations Security Council goal of reducing xenon emissions from medical isotope producers.

Chromatographic separation of radioactive noble gases from xenon

Science.gov (United States)

Akerib, D. S.; Araújo, H. M.; Bai, X.; Bailey, A. J.; Balajthy, J.; Beltrame, P.; Bernard, E. P.; Bernstein, A.; Biesiadzinski, T. P.; Boulton, E. M.; Bramante, R.; Cahn, S. B.; Carmona-Benitez, M. C.; Chan, C.; Chiller, A. A.; Chiller, C.; Coffey, T.; Currie, A.; Cutter, J. E.; Davison, T. J. R.; Dobi, A.; Dobson, J. E. Y.; Druszkiewicz, E.; Edwards, B. N.; Faham, C. H.; Fiorucci, S.; Gaitskell, R. J.; Gehman, V. M.; Ghag, C.; Gibson, K. R.; Gilchriese, M. G. D.; Hall, C. R.; Hanhardt, M.; Haselschwardt, S. J.; Hertel, S. A.; Hogan, D. P.; Horn, M.; Huang, D. Q.; Ignarra, C. M.; Ihm, M.; Jacobsen, R. G.; Ji, W.; Kamdin, K.; Kazkaz, K.; Khaitan, D.; Knoche, R.; Larsen, N. A.; Lee, C.; Lenardo, B. G.; Lesko, K. T.; Lindote, A.; Lopes, M. I.; Manalaysay, A.; Mannino, R. L.; Marzioni, M. F.; McKinsey, D. N.; Mei, D.-M.; Mock, J.; Moongweluwan, M.; Morad, J. A.; Murphy, A. St. J.; Nehrkorn, C.; Nelson, H. N.; Neves, F.; O'Sullivan, K.; Oliver-Mallory, K. C.; Palladino, K. J.; Pease, E. K.; Pech, K.; Phelps, P.; Reichhart, L.; Rhyne, C.; Shaw, S.; Shutt, T. A.; Silva, C.; Solovov, V. N.; Sorensen, P.; Stephenson, S.; Sumner, T. J.; Szydagis, M.; Taylor, D. J.; Taylor, W.; Tennyson, B. P.; Terman, P. A.; Tiedt, D. R.; To, W. H.; Tripathi, M.; Tvrznikova, L.; Uvarov, S.; Verbus, J. R.; Webb, R. C.; White, J. T.; Whitis, T. J.; Witherell, M. S.; Wolfs, F. L. H.; Yazdani, K.; Young, S. K.; Zhang, C.

2018-01-01

The Large Underground Xenon (LUX) experiment operates at the Sanford Underground Research Facility to detect nuclear recoils from the hypothetical Weakly Interacting Massive Particles (WIMPs) on a liquid xenon target. Liquid xenon typically contains trace amounts of the noble radioactive isotopes 85Kr and 39Ar that are not removed by the in situ gas purification system. The decays of these isotopes at concentrations typical of research-grade xenon would be a dominant background for a WIMP search experiment. To remove these impurities from the liquid xenon, a chromatographic separation system based on adsorption on activated charcoal was built. 400 kg of xenon was processed, reducing the average concentration of krypton from 130 ppb to 3.5 ppt as measured by a cold-trap assisted mass spectroscopy system. A 50 kg batch spiked to 0.001 g/g of krypton was processed twice and reduced to an upper limit of 0.2 ppt.

Autoionization in xenon

International Nuclear Information System (INIS)

Knight, R.D.; Wang, L.G.

1986-01-01

The authors have studied both even- and odd-parity autoionizing levels in xenon. These levels lie between the Xe/sup +/ /sup 2/P/sub 3/2/ and /sup 2/P/sub 1/2/ ionization limits. Their technique is laser spectroscopy of a thermal metastable atomic beam of xenon. One-photon laser spectroscopy from the 6s'[1/2]/sub 0/ level has been used to study the np'[1/2]/sub 1/ and np'[3/2]/sub 1/ autoionization doublets, n = 7-20. These had previously been observed only for n = 7,8. The authors are using a MQDT analysis of both discrete and autoionizing even-parity J = 1 levels (five channels) to understand the autoionization line profiles. They have also used two-photon laser spectroscopy from the 6s[3/2]/sub 2/ metastable level via various J = 1,2 6p' levels to observe the odd-parity ns'[1/2]/sub 0 1/, nd'[3/2]/sub 1 2/, and nd'[5/2]/sub 2 3/ autoionizing levels to n > 50. This is the first observation of J not equal to 1 odd-parity autoionization in xenon. The most striking feature of these spectra is the complete absence of the very intense, very broad transitions to nd'[3/2]/sub 1/, which dominate the photoabsorption spectrum from the xenon J = 0 ground state. The other nd' levels (J = 2.3) and ns'[1/2]/sub 0/ are all comparable in width to the previously observed ns'[1/2]/sub 1/ levels. The authors present the results of position and width measurements for these levels

Radon screening for XENON1T

Energy Technology Data Exchange (ETDEWEB)

Lindemann, Sebastian [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)

2015-07-01

Radon with its isotope {sup 222}Rn is one of the dominant sources of internal background in liquid xenon detectors searching for low energetic rare events like WIMP-nucleon scattering. In my talk I briefly review the problem posed by {sup 222}Rn and motivate the screening strategy followed by XENON1T. I introduce the radon emanation technique making use of ultra low background proportional counters and present selected results obtained during the design and construction phases of XENON1T. Finally, I sketch advances in radon emanation assay techniques and give a short outlook on upcoming measurements.

Electron drift in a large scale solid xenon

International Nuclear Information System (INIS)

Yoo, J.; Jaskierny, W.F.

2015-01-01

A study of charge drift in a large scale optically transparent solid xenon is reported. A pulsed high power xenon light source is used to liberate electrons from a photocathode. The drift speeds of the electrons are measured using a 8.7 cm long electrode in both the liquid and solid phase of xenon. In the liquid phase (163 K), the drift speed is 0.193 ± 0.003 cm/μs while the drift speed in the solid phase (157 K) is 0.397 ± 0.006 cm/μs at 900 V/cm over 8.0 cm of uniform electric fields. Therefore, it is demonstrated that a factor two faster electron drift speed in solid phase xenon compared to that in liquid in a large scale solid xenon

Properties of excited xenon atoms in a plasma display panel

International Nuclear Information System (INIS)

Uhm, Han S.; Hong, Byoung H.; Oh, Phil Y.; Choi, Eun H.

2009-01-01

The luminance efficiency of a plasma display panel is directly related to the vacuum ultraviolet (VUV) light that is emitted from excited xenon (Xe) atoms and molecules. It is therefore necessary to investigate the properties of excited xenon atoms. This study presents experimental data associated with the behavior of excited xenon atoms in a PDP discharge cell and compares the data with the theoretical results obtained using an analytical model. The properties of excited xenon atoms in the discharge cells of a plasma display panel are investigated by measuring the excited atom density through the use of laser absorption spectroscopy. The density of the excited xenon atoms increases from zero, reaches its peak, and decreases with time in the discharge cells. The profile of the excited xenon atoms is also studied in terms of the xenon mole fraction. The typical density of the excited xenon atoms in the metastable state is on the order of 10 13 atoms per cubic cm.

Radon depletion in xenon boil-off gas

Energy Technology Data Exchange (ETDEWEB)

Bruenner, S.; Cichon, D.; Lindemann, S.; Undagoitia, T.M.; Simgen, H. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)

2017-03-15

An important background in detectors using liquid xenon for rare event searches arises from the decays of radon and its daughters. We report for the first time a reduction of {sup 222}Rn in the gas phase above a liquid xenon reservoir. We show a reduction factor of >or similar 4 for the {sup 222}Rn concentration in boil-off xenon gas compared to the radon enriched liquid phase. A semiconductor-based α-detector and miniaturized proportional counters are used to detect the radon. As the radon depletion in the boil-off gas is understood as a single-stage distillation process, this result establishes the suitability of cryogenic distillation to separate radon from xenon down to the 10{sup -15} mol/mol level. (orig.)

The Text of the Agreement between Belgium, Denmark, the Federal Republic of Germany, Ireland, Italy, Luxembourg, The Netherlands, the European Atomic Energy Community and the Agency in Connection with the Treaty on the Non-Proliferation of Nuclear Weapons; Texte de l'Accord entre la Belgique, le Danemark, la Republique Federale d' Allemagne, l'Irlande, l'Italie, le Luxembourg, les Pays-Bas, la Communaute Europeenne de l'En-Ergie Atomique et L'Agence En Application Du Traite Sur La Non-Proliferation Des Armes Nucleaires

Energy Technology Data Exchange (ETDEWEB)

NONE

1973-09-14

The text of the Agreement, and of the Protocol thereto, between Belgium, Denmark, the Federal Republic of Germany, Ireland, Italy, Luxembourg, The Netherlands, the European Atomic Energy Community and the Agency in implementation of Article III (1) and (4) of the Treaty on the Non-Proliferation of Nuclear Weapons (reproduced in document INFCIRC/140) is reproduced in this document for the information of all Members [French] Le texte de l'Accord, ainsi que celui du Protocole qui y est joint, entre la Belgique, le Danemark, la Republique fdrale d'Allemae, l'Irlande, l'Italie, le Luxembourg, les Pays-Bas, la Communaute europenne de l'energie atomique et l'Agence condu en application des paragraphes 1 et 4 de l'article III du Traite sur la non proliferation des armes nucleaires sont reproduits dans le present document pour l'information de tous les Membres.

Gross xenon stability

International Nuclear Information System (INIS)

Lewins, J.D.; Wilson, P.P.H.

1997-01-01

The effect of xenon in thermal reactors on steady operation is generally destabilizing. Illustrating this involves the study of appropriate transfer functions, which may be conveniently displayed in three ways: as Bode, Nyquist, and root-locus diagrams. The three forms allow different aspects to be highlighted. These are illustrated for the effect of xenon with allowance not only for the stabilizing effect of the direct yield in fission but also to show the consequences of neglecting the time dependence due to the thermal capacity of the reactor. With careful interpretation, all these forms give an interpretation of stability that is consistent with direct evaluation and promote the understanding of the onset of gross oscillations in power

Contribution to the study of the evolution of radiation induced He in Be O; Etudes sur l'evolution de l'helium produit par reactions nucleaires dans l'oxyde de beryllium

Energy Technology Data Exchange (ETDEWEB)

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

1966-11-15

The purpose of this work in-pile investigation of He formed by (n, 2n) and (n, {alpha}) nuclear reactions, released from irradiated BeO, in the temperature range 1000 - 1350 deg. C. The experimental results show that, for an instantaneous neutron fast flux of 10{sup 13} n cm{sup -2} sec{sup -1}, an equilibrium is attempted, after several days, for a part lower than 20 per cent of the quantity of He formed, theoretically calculated from the neutron cross sections of nuclear reactions, and from the analytical form of the neutron fast flux, releases from the solid. The validity of the values of calculated helium and the gas chromatographic analytical method are also verified by dissolution of the BeO pellets in cryolite. A new fast neutron flux measuring method may be so defined. The discussion of the experimental results enables to establish that the processus of He release is characterized by two phenomena: the first one which controls the release of He atoms out of the solid and the second which reveals a capture processus, connected to the irradiation and probably due to the vacancies induced in the lattice. (author) [French] On etudie en pile le degagement de l'helium forme par reactions nucleaires (n, 2 n) et (n, {alpha}) dans l'oxyde de beryllium irradie entre 1000 et 1350 deg. C. Les resultats experimentaux montrant que, pour un flux rapide instantane de 10{sup 13} n{sub r} cm{sup -2} s{sup -1}, on aboutit, au bout de quelques jours, a un etat d'equilibre pour lequel une partie, inferieure a 20 pour cent de la quantite d'helium forme, calculee theoriquement a partir des sections efficaces des reactions nucleaires et de la forme analytique du flux rapide, s'echappe du solide. On verifie egalement par dissolution des echantillons de BeO dans la cryolithe la validite du calcul de l'helium et de la methode de dosage par chromatographie en phase gazeuse. On peut ainsi definir une methode nouvelle de mesure des flux rapides. La discussion des resultats experimentaux

General phenomenology of underground nuclear explosions; Phenomenologie generale des explosions nucleaires souterraines

Energy Technology Data Exchange (ETDEWEB)

Derlich, S; Supiot, F [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

1969-07-01

An essentially qualitatively description is given of the phenomena related to underground nuclear explosions (explosion of a single unit, of several units in line, and simultaneous explosions). In the first chapter are described the phenomena which are common to contained explosions and to explosions forming craters (formation and propagation of a shock-wave causing the vaporization, the fusion and the fracturing of the medium). The second chapter describes the phenomena related to contained explosions (formation of a cavity with a chimney). The third chapter is devoted to the phenomenology of test explosions which form a crater; it describes in particular the mechanism of formation and the different types of craters as a function of the depth of the explosion and of the nature of the ground. The aerial phenomena connected with explosions which form a crater: shock wave in the air and focussing at a large distance, and dust clouds, are also dealt with. (authors) [French] On donne une description essentiellement qualitative des phenomenes lies aux explosions nucleaires souterraines (explosion d'un seul engin, d'engins en ligne et explosions simultanees). Dans un premier chapitre sont decrits les phenomenes communs aux explosions contenues et aux explosions formant un cratere (formation et propagation d'une onde de choc provoquant la vaporisation, la fusion et la fracturation du milieu). Le deuxieme chapitre decrit les phenomenes lies aux tirs contenus (formation d'une cavite et d'une cheminee). Le troisieme chapitre est consacre a la phenomenologie des tirs formant un cratere et decrit notamment le mecanisme de formation et les differents types de crateres en fonction de la profondeur d'explosion et de la nature du terrain. Les phenomenes aeriens lies aux explosions formant un cratere: onde de pression aerienne et focalisation a grande distance, nuages de poussieres, sont egalement abordes. (auteurs)

Cosmogenic activation of xenon and copper

Energy Technology Data Exchange (ETDEWEB)

Baudis, Laura; Kish, Alexander; Piastra, Francesco [University of Zuerich, Department of Physics, Zuerich (Switzerland); Schumann, Marc [University of Bern, Albert Einstein Center for Fundamental Physics, Bern (Switzerland)

2015-10-15

Rare event search experiments using liquid xenon as target and detection medium require ultra-low background levels to fully exploit their physics potential. Cosmic ray induced activation of the detector components and, even more importantly, of the xenon itself during production, transportation and storage at the Earth's surface, might result in the production of radioactive isotopes with long half-lives, with a possible impact on the expected background. We present the first dedicated study on the cosmogenic activation of xenon after 345 days of exposure to cosmic rays at the Jungfraujoch research station at 3470 m above sea level, complemented by a study of copper which has been activated simultaneously. We have directly observed the production of {sup 7}Be, {sup 101}Rh, {sup 125}Sb, {sup 126}I and {sup 127}Xe in xenon, out of which only {sup 125}Sb could potentially lead to background for a multi-ton scale dark matter search. The production rates for five out of eight studied radioactive isotopes in copper are in agreement with the only existing dedicated activation measurement, while we observe lower rates for the remaining ones. The specific saturation activities for both samples are also compared to predictions obtained with commonly used software packages, where we observe some underpredictions, especially for xenon activation. (orig.)

Lambda-guided calculation method (LGC method) for xenon/CT CBF

Energy Technology Data Exchange (ETDEWEB)

Sase, Shigeru [Anzai Medical Co., Ltd., Tokyo (Japan); Honda, Mitsuru; Kushida, Tsuyoshi; Seiki, Yoshikatsu; Machida, Keiichi; Shibata, Iekado [Toho Univ., Tokyo (Japan). School of Medicine

2001-12-01

A quantitative CBF calculation method for xenon/CT was developed by logically estimating time-course change rate (rate constant) of arterial xenon concentration from that of end-tidal xenon concentration. A single factor ({gamma}) was introduced to correlate the end-tidal rate constant (Ke) with the arterial rate constant (Ka) in a simplified equation. This factor ({gamma}) is thought to reflect the diffusing capacity of the lung for xenon. When an appropriate value is given to {gamma}, it is possible to calculate the arterial rate constant (Calculated Ka) from Ke. To determine {gamma} for each xenon/CT CBF examination, a procedure was established which utilizes the characteristics of white matter lambda; lambda refers to xenon brain-blood partition coefficient. Xenon/CT studies were performed on four healthy volunteers. Hemispheric CBF values (47.0{+-}9.0 ml/100 g/min) with use of Calculated Ka were close to the reported normative values. For a 27-year-old healthy man, the rate constant for the common carotid artery was successfully measured and nearly equal to Calculated Ka. The authors conclude the method proposed in this work, lambda-guided calculation method, could make xenon/CT CBF substantially reliable and quantitative by effective use of end-tidal xenon. (author)

Lambda-guided calculation method (LGC method) for xenon/CT CBF

International Nuclear Information System (INIS)

Sase, Shigeru; Honda, Mitsuru; Kushida, Tsuyoshi; Seiki, Yoshikatsu; Machida, Keiichi; Shibata, Iekado

2001-01-01

A quantitative CBF calculation method for xenon/CT was developed by logically estimating time-course change rate (rate constant) of arterial xenon concentration from that of end-tidal xenon concentration. A single factor (γ) was introduced to correlate the end-tidal rate constant (Ke) with the arterial rate constant (Ka) in a simplified equation. This factor (γ) is thought to reflect the diffusing capacity of the lung for xenon. When an appropriate value is given to γ, it is possible to calculate the arterial rate constant (Calculated Ka) from Ke. To determine γ for each xenon/CT CBF examination, a procedure was established which utilizes the characteristics of white matter lambda; lambda refers to xenon brain-blood partition coefficient. Xenon/CT studies were performed on four healthy volunteers. Hemispheric CBF values (47.0±9.0 ml/100 g/min) with use of Calculated Ka were close to the reported normative values. For a 27-year-old healthy man, the rate constant for the common carotid artery was successfully measured and nearly equal to Calculated Ka. The authors conclude the method proposed in this work, lambda-guided calculation method, could make xenon/CT CBF substantially reliable and quantitative by effective use of end-tidal xenon. (author)

Improvements in or relating to trapping and reuse of radioactive xenon

International Nuclear Information System (INIS)

Bolmsjoe, M.S.; Persson, B.R.

1981-01-01

A method is described suitable for recovering, from a mixture of gases contaning radioactive xenon, a mixture of gases containing an increased concentration of radioactive xenon, which method comprises the steps of passing xenon-containing gas through a bed of activated charcoal to adsorb the xenon therein, thereafter heating the charcoal bed to a temperature within the range of from 200 to 400 0 C, passing a moisture-free sweep gas through the bed when heated to said temperature to desorb xenon therefrom and then collecting the xenon-containing gas thus formed. (author)

Reliability and error analysis on xenon/CT CBF

International Nuclear Information System (INIS)

Zhang, Z.

2000-01-01

This article provides a quantitative error analysis of a simulation model of xenon/CT CBF in order to investigate the behavior and effect of different types of errors such as CT noise, motion artifacts, lower percentage of xenon supply, lower tissue enhancements, etc. A mathematical model is built to simulate these errors. By adjusting the initial parameters of the simulation model, we can scale the Gaussian noise, control the percentage of xenon supply, and change the tissue enhancement with different kVp settings. The motion artifact will be treated separately by geometrically shifting the sequential CT images. The input function is chosen from an end-tidal xenon curve of a practical study. Four kinds of cerebral blood flow, 10, 20, 50, and 80 cc/100 g/min, are examined under different error environments and the corresponding CT images are generated following the currently popular timing protocol. The simulated studies will be fed to a regular xenon/CT CBF system for calculation and evaluation. A quantitative comparison is given to reveal the behavior and effect of individual error resources. Mixed error testing is also provided to inspect the combination effect of errors. The experiment shows that CT noise is still a major error resource. The motion artifact affects the CBF results more geometrically than quantitatively. Lower xenon supply has a lesser effect on the results, but will reduce the signal/noise ratio. The lower xenon enhancement will lower the flow values in all areas of brain. (author)

French achievements in the field of nuclear electronics; Realisations francaises dans le domaine de l'electronique nucleaire

Energy Technology Data Exchange (ETDEWEB)

Doireau, M; Fabre, R; Guillon, H; Guyot, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

Nuclear electronic equipment used by the french Atomic Energy Commission has been developed, with an increasing participation of the radioelectric industry (manufacture under AEC license, contracts for prototypes). The equipment for general use has been standardized and satis the technical specification sheets in which are specified more particularly, the conditions for construction, the choice of the spare parts and the conditions for acceptance by the french AEC at factory. The electronic equipment is classified in nine classes, and a brief description of the principal instruments is given in each class. The reliability of the equipment in use is satisfactory, as it is shown by the mean frequency of faults per 1000 hours operation. (author)Fren. [French] L'appareillage d'electronique nucleaire utilise au Commissariat a l'Energie atomique fran is a ete developpe en demandant un concours de plus en plus important a l'industrie radioelectrique (fabrications sous licence CEA, marches de prototypes, etc...). Le materiel d'emploi courant a ete standardise et repond aux specifications de cahiers des charges ou sont precises en particulier les conditions de realisation du materiel, le choix des pieces detachees et les conditions de recette en usine. L'appareillage electronique est classe en neuf rubriques et une description sommaire des principaux appareils est donnee dans chacune des rubriques. La tenue en service du materiel est satisfaisante, ainsi que le montre la frequence moyenne des pannes observees par 1000 heures de fonctionnement. (auteur)

Irradiation and development of the nuclear emulsions exposed to intense fluxes of thermal neutrons with {gamma} rays; Irradiation et developpement des emulsions nucleaires exposees a des flux intenses de neutrons thermiques, accompagnes de rayons {gamma}

Energy Technology Data Exchange (ETDEWEB)

Faraggi, H; Bonnet, A; Cohen, J [Commissariat a l' Energie Atomique, Lab. du Fort de Chatillon, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1952-07-01

The thermal neutron fluxes provided by nuclear reactors permit the survey of relatively rare phenomenons, and dosage of very weak quantities of some elements. One of the most favorable detection technique are constituted by the use of the nuclear emulsions. one can mention: - the dosage of uranium by counting in the emulsion the number of traces due to fission fragments after irradiation. - The dosage of the lithium and the boron as trace amounts with the help of nuclear reactions (n, {alpha}) and thermal neutrons. - The research of reactions (n, {alpha}) or (n, p) of very weak cross section for middle or heavy elements. These different applications require however important neutrons fluxes. It had therefore obliged us to search for the most favorable irradiation and development of the emulsions conditions, to get the best visibility of the trajectories and decrease the phenomena of fog on the emulsion, which prevents any observation. (M.B.) [French] Les flux de neutrons thermiques fournis par les reacteurs nucleaires permettent l'etude de phenomenes relativement rares, et le dosage de tres faibles quantites de certains elements. Un des moyens de detection les plus favorables est constitue par l'utilisation des emulsions nucleaires. on peut citer: - le dosage de l'uranium par comptage dans l'emulsion du nombre de traces dues aux fragments de fission apres irradiation. - Le dosage du lithium et du bore a l'etat de traces a l'aide des reactions (n, {alpha}) sous l'action des neutrons thermiques. - La recherche de reactions (n,{alpha}) ou (n,p) de tres faible section efficace pour des elements moyens ou lourds. Ces differentes applications necessite cependant des flux de neutrons important. On a donc ete amene a rechercher les conditions les plus favorables d'irradiation et de developpement des emulsions, de maniere a obtenir la meilleure visibilite des trajectoires et diminuer les phenomenes de voile de l'emulsion, qui empeche toute observation. (M.B.)

Irradiation and development of the nuclear emulsions exposed to intense fluxes of thermal neutrons with {gamma} rays; Irradiation et developpement des emulsions nucleaires exposees a des flux intenses de neutrons thermiques, accompagnes de rayons {gamma}

Energy Technology Data Exchange (ETDEWEB)

Faraggi, H.; Bonnet, A.; Cohen, J. [Commissariat a l' Energie Atomique, Lab. du Fort de Chatillon, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1952-07-01

The thermal neutron fluxes provided by nuclear reactors permit the survey of relatively rare phenomenons, and dosage of very weak quantities of some elements. One of the most favorable detection technique are constituted by the use of the nuclear emulsions. one can mention: - the dosage of uranium by counting in the emulsion the number of traces due to fission fragments after irradiation. - The dosage of the lithium and the boron as trace amounts with the help of nuclear reactions (n, {alpha}) and thermal neutrons. - The research of reactions (n, {alpha}) or (n, p) of very weak cross section for middle or heavy elements. These different applications require however important neutrons fluxes. It had therefore obliged us to search for the most favorable irradiation and development of the emulsions conditions, to get the best visibility of the trajectories and decrease the phenomena of fog on the emulsion, which prevents any observation. (M.B.) [French] Les flux de neutrons thermiques fournis par les reacteurs nucleaires permettent l'etude de phenomenes relativement rares, et le dosage de tres faibles quantites de certains elements. Un des moyens de detection les plus favorables est constitue par l'utilisation des emulsions nucleaires. on peut citer: - le dosage de l'uranium par comptage dans l'emulsion du nombre de traces dues aux fragments de fission apres irradiation. - Le dosage du lithium et du bore a l'etat de traces a l'aide des reactions (n, {alpha}) sous l'action des neutrons thermiques. - La recherche de reactions (n,{alpha}) ou (n,p) de tres faible section efficace pour des elements moyens ou lourds. Ces differentes applications necessite cependant des flux de neutrons important. On a donc ete amene a rechercher les conditions les plus favorables d'irradiation et de developpement des emulsions, de maniere a obtenir la meilleure visibilite des trajectoires et diminuer les phenomenes de voile de l'emulsion, qui

Potential for large-scale uses for fission-product Xenon

International Nuclear Information System (INIS)

Rohrmann, C.A.

1983-03-01

Of all fission products in spent, low-enrichment-uranium power-reactor fuels, xenon is produced in the highest yield - nearly one cubic meter, STP, per metric ton. In aged fuels which may be considered for processing in the US, radioactive xenon isotopes approach the lowest limits of detection. The separation from accompanying radioactive 85 Kr is the essential problem; however, this is state-of-the-art technology which has been demonstrated on the pilot scale to yield xenon with pico-curie levels of 85 Kr contamination. If needed for special applications, such levels could be further reduced. Environmental considerations require the isolation of essentially all fission-product krypton during fuel processing. Economic restraints assure that the bulk of this krypton will need to be separated from the much-more-voluminous xenon fraction of the total amount of fission gas. Xenon may thus be discarded or made available for uses at probably very low cost. In contrast with many other fission products which have unique radioactive characteristics which make them useful as sources of heat, gamma and x-rays, and luminescence - as well as for medicinal diagnostics and therapeutics - fission-product xenon differs from naturally occurring xenon only in its isotopic composition which gives it a slightly hgiher atomic weight, because of the much higher concentrations of the 134 Xe and 136 Xe isotopes. Therefore, fission-product xenon can most likely find uses in applications which already exist but which can not be exploited most beneficially because of the high cost and scarcity of natural xenon. Unique uses would probably include applications in improved incandescent light illumination in place of krypton and in human anesthesia

Utilisation de l'essai comete et du biomarqueur gamma-H2AX pour detecter les dommages induits a l'ADN cellulaire par le 5-bromodeoxyuridine post-irradiation

Science.gov (United States)

La Madeleine, Carole

Ce memoire est presente a la Faculte de medecine et des sciences de la sante de l'Universite de Sherbrooke en vue de l'obtention du grade de maitre es sciences (M.Sc.) en radiobiologie (2009). Un jury a revise les informations contenues dans ce memoire. Il etait compose de professeurs de la Faculte de medecine et des sciences de la sante soit : Darel Hunting PhD, directeur de recherche (departement de medecine nucleaire et radiobiologie), Leon Sanche PhD, directeur de recherche (departement de medecine nucleaire et radiobiologie), Richard Wagner PhD, membre du programme (departement de medecine nucleaire et radiobiologie) et Guylain Boissonneault PhD, membre exterieur au programme (departement de biochimie). Le 5-bromodeoxyuridine (BrdU), un analogue halogene de la thymidine reconnu depuis les annees 60 comme etant un excellent radiosensibilisateur. L'hypothese la plus repandue au sujet de l'effet radio sensibilisant du BrdU est qu'il augmente le nombre de cassures simple et double brin lorsqu'il est incorpore dans l'ADN de la cellule et expose aux radiations ionisantes. Toutefois, de nouvelles recherches semblent remettre en question les observations precedentes. Ces dernieres etudes ont confirme que le BrdU est un bon radiosensibilisateur, car il augmente les dommages radio-induits dans l'ADN. Mais, c'est en etant incorpore dans une region simple brin que le BrdU radiosensibilise l'ADN. Ces recherches ont egalement revele pour la premiere fois un nouveau type de dommages produits lors de l'irradiation de l'ADN contenant du BrdU : les dimeres interbrins. Le but de ces travaux de recherche est de determiner si la presence de bromodeoxyuridine dans l'ADN augmente l'induction de bris simple et / ou double brin chez les cellules irradiees en utilisant de nouvelles techniques plus sensibles et specifiques que celles utilisees auparavant. Pour ce faire, les essais cometes et la detection des foci H2AX phosphorylee pourraient permettre d'etablir les effets engendres par

The control equipment of the Melusine II reactor; L'equipement de controle du reacteur Melusine II

Energy Technology Data Exchange (ETDEWEB)

Cordelle, M; Delcroix, V; Denis, P; Gariod, R

1963-07-01

Melusine II, low-power reactor, used for the study of Siloe core has diverged at the CEA Grenoble, the 23. May 1962; its monitoring board studied and carried out in this center is the first in France to be entirely transistorized. The first months of running have justified the hope put in the new electronics to improve the stability and the safety of running. The article describes the design of the control and gives the main characteristics of the measurement chains and of the actions on reactivity. (O.M.) [French] Melusine II, reacteur de faible puissance destine a l'etude du coeur de Siloe a diverge au Centre d'Etudes Nucleaires de Grenoble, le 23 mai 1962, son tableau de controle etudie et realise dans ce Centre est le premier en France a etre entierement transistorise. Les premiers mois de fonctionnement ont justifie l'espoir mis dans la nouvelle electronique pour ameliorer la stabilite et la surete de fonctionnement. L'article decrit la conception du controle et donne les principales caracteristiques des chaines de mesure et des actions sur la reactivite. (auteurs)

The XENON project for dark matter direct detection at LNGS

Science.gov (United States)

Molinario, Andrea

2017-12-01

The XENON project at INFN Laboratori Nazionali del Gran Sasso, Italy, aims at dark matter direct detection with liquid xenon dual-phase time projection chambers. Latest results of XENON100 detector exclude various models of leptophilic dark matter. A search for low mass weakly interacting massive particles was also performed, lowering the energy threshold for detection to 0.7 keV for nuclear recoils. The multi-ton XENON1T detector is fully installed and operating. It is expected to reach a sensitivity a factor 100 better than XENON100 with a 2 ton·year exposure.

Ventilator-driven xenon ventilation studies

International Nuclear Information System (INIS)

Chilcoat, R.T.; Thomas, F.D.; Gerson, J.I.

1984-01-01

A modification of a common commercial Xe-133 ventilation device is described for mechanically assisted ventilation imaging. The patient's standard ventilator serves as the power source controlling the ventilatory rate and volume during the xenon study, but the gases in the two systems are not intermixed. This avoids contamination of the ventilator with radioactive xenon. Supplemental oxygen and positive end-expiratory pressure (PEEP) are provided if needed. The system can be converted quickly for conventional studies with spontaneous respiration

Exploring new Xe-129 chemical shift ranges in HXeY compounds: hydrogen more relativistic than xenon

Czech Academy of Sciences Publication Activity Database

Lantto, P.; Standara, Stanislav; Riedel, S.; Vaara, J.; Straka, Michal

2012-01-01

Roč. 14, č. 31 (2012), s. 10944-10952 ISSN 1463-9076 R&D Projects: GA ČR GA203/09/2037 Grant - others:GA MŠk(CZ) LM2010005; 7th European Framework Program(XE) 230955; CEITEC(XE) CZ.1.05/1.1.00/02.0068 Institutional research plan: CEZ:AV0Z40550506 Keywords : 129Xe NMR * novel Xe compounds * relativistic effects * rare-gas * ab-initio * NMR properties Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.829, year: 2012

Investigations on a highly luminous condensed xenon scintillator

International Nuclear Information System (INIS)

Lansiart, Alain; Seigneur, Alain; Morucci, J.-P.

1976-12-01

The means of creating a maximal amount of light by absorption of gamma radiation in condensed xenon were investigated. One of the methods relies on the light production around wires in liquid xenon when several kilovolts are applied to them. Another method uses the saturating vapor present over solid xenon; the electric field pulls out electrons from the solid and accelerates them in the gas phase where they produce light through inelastic collisions [fr

Search for double beta decay processes of {sup 124}Xe with XENON100 and XENON1T

Energy Technology Data Exchange (ETDEWEB)

Fieguth, Alexander [IKP, Westfaelische-Wilhelms-Universitaet Muenster (Germany)

2016-07-01

Driven by the search for dark matter particles the XENON dark matter project recently installed its next stage multi-ton experiment XENON1T at the LNGS, which will probe the spin-indpendent-WIMP-Nucleon cross section down to 2.10{sup -47} cm{sup 2}. Besides its main purpose different particle physics topics can be addressed by the taken data. One example are the double beta decay processes of natural isotope {sup 124}Xe. This isotope is expected to decay via two-neutrino double electron capture (2νECEC) and due to its high Q-value of 2864 keV additionally through 2νβ{sup +}β{sup +}. Since these processes have not been detected so far, there is only a lower limit the respective half-life (e.g. > 4.7.10{sup 21} yr for 2νECEC). A detection of the 2νECEC is possible using XENON1T data by looking for its clear signature of secondary X-rays or Auger electrons and at least new lower half-life limits for all other decay channels can be obtained. While these processes are expected from standard model physics, a detection of a decay without neutrinos (e.g 0νECEC) would hint towards beyond the standard model physics and could derive conclusions on the neutrino mass. Until XENON1T is taking data, the search for all processes can be tested in the recorded data of its predecessor XENON100.

Xenon Acquisition Strategies for High-Power Electric Propulsion NASA Missions

Science.gov (United States)

Herman, Daniel A.; Unfried, Kenneth G.

2015-01-01

The benefits of high-power solar electric propulsion (SEP) for both NASA's human and science exploration missions combined with the technology investment from the Space Technology Mission Directorate have enabled the development of a 50kW-class SEP mission. NASA mission concepts developed, including the Asteroid Redirect Robotic Mission, and those proposed by contracted efforts for the 30kW-class demonstration have a range of xenon propellant loads from 100's of kg up to 10,000 kg. A xenon propellant load of 10 metric tons represents greater than 10% of the global annual production rate of xenon. A single procurement of this size with short-term delivery can disrupt the xenon market, driving up pricing, making the propellant costs for the mission prohibitive. This paper examines the status of the xenon industry worldwide, including historical xenon supply and pricing. The paper discusses approaches for acquiring on the order of 10 MT of xenon propellant considering realistic programmatic constraints to support potential near-term NASA missions. Finally, the paper will discuss acquisitions strategies for mission campaigns utilizing multiple high-power solar electric propulsion vehicles requiring 100's of metric tons of xenon over an extended period of time where a longer term acquisition approach could be implemented.

Quantitative measurements of small isotopic samples in gaseous mixtures by utilization of some nuclear properties; Etude des possibilites de mesures de faibles quantites de gaz radioactifs dans un melange en utilisant simultanement plusieurs proprietes nucleaires

Energy Technology Data Exchange (ETDEWEB)

Maragnon, J; Delperie, C

1967-12-01

The question is to define the characteristics of a group of measurements allowing the analysis of traces of radioactive rare gases in gas mixtures of different composition. To distinguish the radioactive isotopes from each other and the activity level reaching 10{sup 6} due to their nuclear properties, the method was chosen to use several nuclear properties: gamma radiation energy, beta particle energy, lifetime of excited states. The choice of a plastic scintillator as beta detector allows to answer satisfactorilly to this demand by measurement of nuclear constants because of the short de/excitation time of this detector. Another advantage is that it can be a reservoir for the sample without any destruction nor modification of the sample. The study has been based on the mixture of Kr-85, the analysis of other rare gases follwos immediately from the adopted principle. [French] Les auteurs ont oriente leur recherche vers une solution permettant de distinguer les isotopes radioactifs les uns des autres et dans des rapports d'activite pouvant atteindre 10{sup 6}, grace a plusieurs de leurs proprietes nucleaires, energie de rayonnement gamma, energie de la particule beta, temps de vie des niveaux excites. Le choix d'un scintillateur plastique comme detecteur beta permet de repondre d'une maniere satisfaisante a la mesure des constantes nucleaires en raison du temps de de/excitation rapide de ce scintillateur. Il offre en outre l'avantage de pouvoir servir de reservoir a l'echantillon sans entrainer aucune destruction ni modification de celui-ci. L'etude a ete basee sur la mixture de Kr-85, l'analyse des autre gaz rares decoulant immediatement du principe adopte. (auteur)

Micro manometer and pitot tube for measuring the velocity distribution in a natural convection water stream between two vertical parallel plates (1961); Micromano metre et tube de pitot destines a l'exploration du profil de vitesse dans un ecoulement d'eau de convection naturelle entre deux plaques verticales paralleles (1961)

Energy Technology Data Exchange (ETDEWEB)

Santon, L; Vernier, Ph [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1961-07-01

For heat transfer studies in certain cases of cooling in swimming-pool type nuclear reactors, a knowledge of the distribution of the velocities between two heating elements is of prime importance. A Pitot tube and a micro-manometer have been developed for making these measurements on an experimental model. (authors) [French] Pour l'etude du transfert de chaleur dans certains cas de refroidissement des reacteurs nucleaires du type piscine, la connaissance de la repartition des vitesses entre deux elements chauffants est primordiale. On a mis au point un tube de Pitot et un micromanometre pour effectuer ces mesures sur une maquette experimentale. (auteurs)

Removing krypton from xenon by cryogenic distillation to the ppq level

Science.gov (United States)

Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Amaro, F. D.; Anthony, M.; Arneodo, F.; Barrow, P.; Baudis, L.; Bauermeister, B.; Benabderrahmane, M. L.; Berger, T.; Breur, P. A.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Bütikofer, L.; Calvén, J.; Cardoso, J. M. R.; Cervantes, M.; Cichon, D.; Coderre, D.; Colijn, A. P.; Conrad, J.; Cussonneau, J. P.; Decowski, M. P.; de Perio, P.; Di Gangi, P.; Di Giovanni, A.; Diglio, S.; Duchovni, E.; Eurin, G.; Fei, J.; Ferella, A. D.; Fieguth, A.; Franco, D.; Fulgione, W.; Gallo Rosso, A.; Galloway, M.; Gao, F.; Garbini, M.; Geis, C.; Goetzke, L. W.; Grandi, L.; Greene, Z.; Grignon, C.; Hasterok, C.; Hogenbirk, E.; Huhmann, C.; Itay, R.; Kaminsky, B.; Kessler, G.; Kish, A.; Landsman, H.; Lang, R. F.; Lellouch, D.; Levinson, L.; Calloch, M. Le; Lin, Q.; Lindemann, S.; Lindner, M.; Lopes, J. A. M.; Manfredini, A.; Maris, I.; Undagoitia, T. Marrodán; Masbou, J.; Massoli, F. V.; Masson, D.; Mayani, D.; Meng, Y.; Messina, M.; Micheneau, K.; Miguez, B.; Molinario, A.; Murra, M.; Naganoma, J.; Ni, K.; Oberlack, U.; Orrigo, S. E. A.; Pakarha, P.; Pelssers, B.; Persiani, R.; Piastra, F.; Pienaar, J.; Piro, M.-C.; Pizzella, V.; Plante, G.; Priel, N.; Rauch, L.; Reichard, S.; Reuter, C.; Rizzo, A.; Rosendahl, S.; Rupp, N.; Saldanha, R.; Santos, J. M. F. dos; Sartorelli, G.; Scheibelhut, M.; Schindler, S.; Schreiner, J.; Schumann, M.; Lavina, L. Scotto; Selvi, M.; Shagin, P.; Shockley, E.; Silva, M.; Simgen, H.; Sivers, M. v.; Stein, A.; Thers, D.; Tiseni, A.; Trinchero, G.; Tunnell, C.; Upole, N.; Wang, H.; Wei, Y.; Weinheimer, C.; Wulf, J.; Ye, J.; Zhang, Y.; Cristescu, I.

2017-05-01

The XENON1T experiment aims for the direct detection of dark matter in a detector filled with 3.3 tons of liquid xenon. In order to achieve the desired sensitivity, the background induced by radioactive decays inside the detector has to be sufficiently low. One major contributor is the β -emitter ^{85}Kr which is present in the xenon. For XENON1T a concentration of natural krypton in xenon ^{nat}Kr/Xe McCabe-Thiele approach is described. The system demonstrated a krypton reduction factor of 6.4\\cdot 10^5 with thermodynamic stability at process speeds above 3 kg/h. The resulting concentration of ^{nat}Kr/Xe<26 ppq is the lowest ever achieved, almost one order of magnitude below the requirements for XENON1T and even sufficient for future dark matter experiments using liquid xenon, such as XENONnT and DARWIN.

Professional Nuclear Materials Management; Gestion Industrielle des Matieres Nucleaires; Obrashchenie s yadernymi materialami na professional'nom urovne; Administracion Eficiente de Materiales Nucleares

Energy Technology Data Exchange (ETDEWEB)

Forcella, A. A.; O' Leary, W. J. [Allis-Chalmers Manufacturing Company, Bethesda, MD (United States)

1966-02-15

. (author) [French] Le memoire expose en quoi consiste la gestion des matieres nucleaires dans une centrale nucleaire type, aux Etats-Unis. Comme le reacteur en question est partiellement finance a l'aide de capitaux prives, l'une des principales obligations de l'exploitant est d'assurer la protection et la rentabilite des investissements. Etant donne que les matieres nucleaires sont d'une valeur intrinseque elevee, il faut constamment proceder a des controles appropries allant au-dela des mesures de securite et de la comptabilite interessant les matieresnucleaires proprement dites afin de reduire les pertes au minimum. Il faut faire preuve de clairvoyance et planifier judicieusement pour prevenir toute perte supplementaire de capital provenant de frais inutiles ou d'un manque a gagner dans divers secteurs de l'exploitation. C'est ainsi que le gestionnaire de matieres nucleaires doit prendre des dispositions pour garantir la bonne marche des operations et assurer le respect des plans d'execution par une liaison et un controle constants, dans les domaines suivants? a) acquisition du combustible et des elements combustibles, b) utilisation des elements combustibles dans le reacteur et c) recuperation, dans le combustible irradie, des produits et matieres presentant de l'interet. Pendant la periode qui precede l'utilisation du reacteur, il faut faire une place importante dans la planification et les travaux preparatoires aux considerations d'economie dans la conception des elements combustibles, en ce qui concerne leur fabrication, leur manutention, leur transport et leur remplacement. Les differentes etapes de la fabrication doivent etre planifiees de facon a reduire au minimum le manque a gagner du a des periodes improductives d'entreposage de matieres tres couteuses. Pendant la marche du reacteur, il faut assurer une combustion maximale de la matiere fissile par des redistributions appropriees du combustible dans le coeur du reacteur. Parallelement, les temps morts dus a

XAS characterisation of xenon bubbles in uranium dioxide

Energy Technology Data Exchange (ETDEWEB)

Martin, P. [CEA Cadarache, DEN/DEC/SESC/LLCC, Bat. 130, 13108 St. Paul Lez Durance (France)], E-mail: martinp@drncad.cea.fr; Garcia, P.; Carlot, G.; Sabathier, C.; Valot, C. [CEA Cadarache, DEN/DEC/SESC/LLCC, Bat. 130, 13108 St. Paul Lez Durance (France); Nassif, V. [CEA Grenoble, DSM/DRFMC/SP2M/NRS, 17 Avenue des Martyrs, 38054 Grenoble Cedex 9 (France); Proux, O. [Laboratoire de Geophysique Interne et Tectonophysique, UMR CNRS/Universite Joseph Fourier, 1381 rue de la Piscine, Domaine Universitaire, 38400 Saint-Martin-D' Heres (France); Hazemann, J.-L. [Institut Neel, CNRS, 25 Avenue des Martyrs, BP 166, 38042 Grenoble Cedex 9 (France)

2008-06-15

X-ray absorption spectroscopy experiments were performed on a set of uranium dioxide samples implanted with 10{sup 17} xenon cm{sup -2} at 800 keV (8 at.% at 140 nm). EXAFS measurements performed at 12 K showed that during implantation the gas forms highly pressurised nanometre size inclusions. Bubble pressures were estimated at 2.8 {+-} 0.3 GPa at low temperature. Following the low energy xenon implantation, samples were annealed between 1073 and 1773 K for several hours. Stability of nanometre size highly pressurized xenon aggregates in UO{sub 2} is demonstrated up to 1073 K as for this temperature almost no modification of the xenon environment was observed. Above this temperature, bubbles will trap migrating vacancies and their inner pressure is seen to decrease substantially.

Dark matter search with XENON1T

NARCIS (Netherlands)

Aalbers, J.

2018-01-01

Most matter in the universe consists of 'dark matter' unknown to particle physics. Deep underground detectors such as XENON1T attempt to detect rare collisions of dark matter with ordinary atoms. This thesis describes the first dark matter search of XENON1T, how dark matter signals would appear in

The Technical Training Programme for Nuclear Power Station Personnel; Programme de formation technique du personnel des centrales nucleaires; Programma tekhnicheskoj podgotovki personala yadernoj ehlektrostantsii; El programa de formacion tecnica del personal de una central nucleoelectrica

Energy Technology Data Exchange (ETDEWEB)

Howey, G. R. [Hydro-Electric Power Commission of Ontario, Toronto, Ontario (Canada)

1963-10-15

.), responsible for maintenance of all mechanical equipment; and (5) Service maintainers: responsible for a wide variety of less skilled tasks requiring lower qualifications. In addition to these general categories a few specialists are required, such as chemists and radiation protection officers. Organization of the NPD staff and training for future nuclear-power needs will be discussed. (author) [French] La centrale nucleaire de demonstration canadienne (NPD), creee par un organisme federal, l'Atomic Energy of Canada Limited, est exploitee par une compagnie provinciale de distribution d'electricite, la Hydro-Electric Power Commission of Ontario, qui pourvoit aussi aux besoins en personnel. Le recrutement et la formation du personnel de la centrale ont ete difficiles du fait que, recemment encore, la plupart des besoins en electricite de l'Ontario pouvaient etre satisfaits par les abondantes ressources hydro-electriques de cette province. La multiplication des centrales thermiques, depuis 1950, a cree une enorme demande de personnel. Pour faire face a cette situation, on a organise la formation de personnel pour les centrales nucleaires de la maniere suivante: a) un groupe initial d'ingenieurs a ete selectionne parmi des specialistes ayant une vaste experience des travaux dans le domaine nucleaire de l 'exploitation des centrales thermiques et de la production d'electricite; b) on a selectionne un autre groupe d'operateurs et d'agents des services d'entretien hautement qualifies; c) ces groupes ont recu une formation systematique comprenant l'exploitation de centrales nucleaires et de centrales thermiques a charbon, un enseignement theorique et pratique et des instructions donnees par les specialistes qui ont concu les plans de NPD ; d) un centre de formation nucleaire a ete cree et charge de la selection et de la formation du personnel supplementaire ainsi que de l 'organisation des examens officiels; il doit s'assurer, d'une maniere generale, de la competence du personnel

Xenon-computed tomography of kidney transplants

International Nuclear Information System (INIS)

Mutze, S.; Reichmuth, B.; Suess, C.; Lippert, J.; Ewert, R.

1994-01-01

Xenon-CT is an established method for determining cerebral perfusion, while applications in other organs are rare. We evaluated the diagnostic potential of measuring the regional Renal Blood Flow (rRBF) in 10 patients with transplanted kidneys by xenon-CT. We found significant differences in the rRBF between the renal medulla and the cortex. There were no differences between normal renal transplants and transplants with chronic rejection. (orig.) [de

The potential for large scale uses for fission product xenon

International Nuclear Information System (INIS)

Rohrmann, C.A.

1983-01-01

Of all fission products in spent, low enrichment, uranium, power reactor fuels xenon is produced in the highest yield - nearly one cubic meter, STP, per metric ton. In aged fuels which may be considered for processing in the U.S. radioactive xenon isotopes approach the lowest limits of detection. The separation from accompanying radioactive 85 Kr is the essential problem; however, this is state of the art technology which has been demonstrated on the pilot scale to yield xenon with pico-curie levels of 85 Kr contamination. If needed for special applications, such levels could be further reduced. Environmental considerations require the isolation of essentially all fission product krypton during fuel processing. Economic restraints assure that the bulk of this krypton will need to be separated from the much more voluminous xenon fraction of the total amount of fission gas. Xenon may thus be discarded or made available for uses at probably very low cost. In contrast with many other fission products which have unique radioactive characteristics which make them useful as sources of heat, gamma and x-rays and luminescence as well as for medicinal diagnostics and therapeutics fission product xenon differs from naturally occurring xenon only in its isotopic composition which gives it a slightly higher atomic weight, because of the much higher concentrations of the 134 X and 136 Xe isotopes. Therefore, fission product xenon can most likely find uses in applications which already exist but which can not be exploited most beneficially because of the high cost and scarcity of natural xenon. Unique uses would probably include applications in improved incandescent light illumination in place of krypton and in human anesthesia

Imminent perspectives for industrial application of atomic energy; Perspectives imminentes de l'application industrielle de l'energie atomique

Energy Technology Data Exchange (ETDEWEB)

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

1955-07-01

This conference raises an inventory of industrial applications and their perspectives for the year 1955. The speaker extrapolate for the forthcoming years the evolution of the role of the nuclear, the nuclear fuel, the different, types of atomic reactors and the state of advancement for different countries. (M.B.) [French] Cette conference dresse un etat des lieux des applications industrielles et de leurs perspectives pour l'annee 1955. L'orateur aborde entre autre l'evolution du role du nucleaire dans les annees a venir, le combustible nucleaire, les differents types de piles atomiques et l'etat d'avancement des differents pays. (M.B.)

Hugoniot measurements of double-shocked precompressed dense xenon plasmas

Science.gov (United States)

Zheng, J.; Chen, Q. F.; Gu, Y. J.; Chen, Z. Y.

2012-12-01

The current partially ionized plasmas models for xenon show substantial differences since the description of pressure and thermal ionization region becomes a formidable task, prompting the need for an improved understanding of dense xenon plasmas behavior at above 100 GPa. We performed double-shock compression experiments on dense xenon to determine accurately the Hugoniot up to 172 GPa using a time-resolved optical radiation method. The planar strong shock wave was produced using a flyer plate impactor accelerated up to ˜6 km/s with a two-stage light-gas gun. The time-resolved optical radiation histories were acquired by using a multiwavelength channel optical transience radiance pyrometer. Shock velocity was measured and mass velocity was determined by the impedance-matching methods. The experimental equation of state of dense xenon plasmas are compared with the self-consistent fluid variational calculations of dense xenon in the region of partial ionization over a wide range of pressures and temperatures.

The unbearable lightness of being: CDMS versus XENON

CERN Document Server

Frandsen, Mads T; McCabe, Christopher; Sarkar, Subir; Schmidt-Hoberg, Kai

2013-01-01

The CDMS-II collaboration has reported 3 events in a Si detector, which are consistent with being nuclear recoils due to scattering of Galactic dark matter particles with a mass of about 8.6 GeV and a cross-section on neutrons of about 2 x 10^-41 cm^2. While a previous result from the XENON10 experiment has supposedly ruled out such particles as dark matter, we find by reanalysing the XENON10 data that this is not the case. Some tension remains however with the upper limit placed by the XENON100 experiment, independently of astrophysical uncertainties concerning the Galactic dark matter distribution. We explore possible ways of ameliorating this tension by altering the properties of dark matter interactions. Nevertheless, even with standard couplings, light dark matter is consistent with both CDMS and XENON10/100.

Xenon ventilation CT using dual-source and dual-energy technique in children with bronchiolitis obliterans: correlation of xenon and CT density values with pulmonary function test results

International Nuclear Information System (INIS)

Goo, Hyun Woo; Yang, Dong Hyun; Seo, Joon Beom; Chae, Eun Jin; Lee, Jeongjin; Hong, Soo-Jong; Yu, Jinho; Kim, Byoung-Ju; Krauss, Bernhard

2010-01-01

Xenon ventilation CT using dual-source and dual-energy technique is a recently introduced, promising functional lung imaging method. To expand its clinical applications evidence of additional diagnostic value of xenon ventilation CT over conventional chest CT is required. To evaluate the usefulness of xenon ventilation CT using dual-source and dual-energy technique in children with bronchiolitis obliterans (BO). Seventeen children (age 7-18 years; 11 boys) with BO underwent xenon ventilation CT using dual-source and dual-energy technique. Xenon and CT density values were measured in normal and hyperlucent lung regions on CT and were compared between the two regions. Volumes of hyperlucent regions and ventilation defects were calculated with thresholds determined by visual and histogram-based analysis. Indexed volumes of hyperlucent lung regions and ventilation defects were correlated with pulmonary function test results. Effective doses of xenon CT were calculated. Xenon (14.6 ± 6.4 HU vs 26.1 ± 6.5 HU; P 25-75 , (γ = -0.68-0.88, P ≤ 0.002). Volume percentages of xenon ventilation defects (35.0 ± 16.4%)] were not significantly different from those of hyperlucent lung regions (38.2 ± 18.6%). However, mismatches between the volume percentages were variable up to 21.4-33.3%. Mean effective dose of xenon CT was 1.9 ± 0.5 mSv. In addition to high-resolution anatomic information, xenon ventilation CT using dual-source and dual-energy technique demonstrates impaired regional ventilation and its heterogeneity accurately in children with BO without additional radiation exposure. (orig.)

Distribution of xenon between gaseous and liquid CO2

International Nuclear Information System (INIS)

Ackley, R.D.; Notz, K.J.

1976-10-01

The distribution of xenon at low concentrations between gaseous and liquid CO 2 was measured over essentially the entire liquid range of CO 2 . These measurements involved using a collimated radiation-detection cell to determine the relative quantities of 133 Xe-traced xenon in the separate phases contained in a vertical cylinder under isothermal conditions. The results are expressed in terms of a distribution ratio (mole fraction of xenon in the gaseous phase divided by mole fraction of xenon in the liquid phase) which decreased from 7.53 at -54.8 0 C to 1.10 at 30.5 0 C. These data were used to calculate various other solubility-related quantities

Sensitivity of gaseous xenon ionisation chambers (1961)

International Nuclear Information System (INIS)

Schuhl, C.

1960-01-01

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) [fr

Effect of capacitor loss on discharging characteristics of xenon flash lamp

International Nuclear Information System (INIS)

Zhang Chu; Lin Dejiang; Xu Chunmei; Shen Hongbin; Chen Xiaohan

2012-01-01

The effect of storage capacitor's loss on the discharging characteristics of the xenon flash lamp was studied, and the xenon flash lamp discharging circuit was analyzed and improved. The capacitor can be equivalent to a series of an ideal capacitor and loss resistance. The improved formula of the xenon lamp discharging characteristics was given when actual capacitance loss is not zero, and the xenon lamp discharging current and discharging power are calculated and analyzed in detail with the increase of the capacitor loss. The results show that the increase of loss will lead to the decrease of xenon lamp discharging current and peak power and the xenon lamp flash time, and influence laser pumping efficiency. The loss will also lead to the capacitor inverse charging in LC discharging circuit; this will influence normal working of the capacitor and decrease the lift of the xenon lamp. The actual energy storage capacitor charging and discharging experiments show that the increase of capacitor loss will lead to the decrease of xenon lamp light-emitting waveform peak, shortening of the flash time and increase of the electrode sputter, thus verity, the reasonableness of theoretical analysis. In addition, the experiments show that environmental factors have very significant impact on the increase of the storage capacitor loss. (authors)

Xenon Acquisition Strategies for High-Power Electric Propulsion NASA Missions

Science.gov (United States)

Herman, Daniel A.; Unfried, Kenneth G.

2015-01-01

Solar electric propulsion (SEP) has been used for station-keeping of geostationary communications satellites since the 1980s. Solar electric propulsion has also benefitted from success on NASA Science Missions such as Deep Space One and Dawn. The xenon propellant loads for these applications have been in the 100s of kilograms range. Recent studies performed for NASA's Human Exploration and Operations Mission Directorate (HEOMD) have demonstrated that SEP is critically enabling for both near-term and future exploration architectures. The high payoff for both human and science exploration missions and technology investment from NASA's Space Technology Mission Directorate (STMD) are providing the necessary convergence and impetus for a 30-kilowatt-class SEP mission. Multiple 30-50- kilowatt Solar Electric Propulsion Technology Demonstration Mission (SEP TDM) concepts have been developed based on the maturing electric propulsion and solar array technologies by STMD with recent efforts focusing on an Asteroid Redirect Robotic Mission (ARRM). Xenon is the optimal propellant for the existing state-of-the-art electric propulsion systems considering efficiency, storability, and contamination potential. NASA mission concepts developed and those proposed by contracted efforts for the 30-kilowatt-class demonstration have a range of xenon propellant loads from 100s of kilograms up to 10,000 kilograms. This paper examines the status of the xenon industry worldwide, including historical xenon supply and pricing. The paper will provide updated information on the xenon market relative to previous papers that discussed xenon production relative to NASA mission needs. The paper will discuss the various approaches for acquiring on the order of 10 metric tons of xenon propellant to support potential near-term NASA missions. Finally, the paper will discuss acquisitions strategies for larger NASA missions requiring 100s of metric tons of xenon will be discussed.

Numerical study on xenon positive column discharges of mercury-free lamp

International Nuclear Information System (INIS)

Ouyang, Jiting; He, Feng; Miao, Jinsong; Wang, Jianqi; Hu, Wenbo

2007-01-01

In this paper, the numerical study has been performed on the xenon positive column discharges of mercury-free fluorescent lamp. The plasma discharge characteristics are analyzed by numerical simulation based on two-dimensional fluid model. The effects of cell geometry, such as the dielectric layer, the electrode width, the electrode gap, and the cell height, and the filling gas including the pressure and the xenon percentage are investigated in terms of discharge current and discharge efficiency. The results show that a long transient positive column will form in the xenon lamp when applying ac sinusoidal power and the lamp can operate in a large range of voltage and frequency. The front dielectric layer of the cell plays an important role in the xenon lamp while the back layer has little effect. The ratio of electrode gap to cell height should be large to achieve a long positive column xenon lamp and higher efficiency. Increase of pressure or xenon concentration results in an increase of discharge efficiency and voltage. The discussions will be helpful for the design of commercial xenon lamp cells

Removing krypton from xenon by cryogenic distillation to the ppq level

Energy Technology Data Exchange (ETDEWEB)

Aprile, E.; Anthony, M.; De Perio, P.; Gao, F.; Goetzke, L.W.; Greene, Z.; Messina, M.; Plante, G.; Rizzo, A.; Zhang, Y. [Columbia University, Physics Department, New York, NY (United States); Aalbers, J.; Breur, P.A.; Brown, A.; Colijn, A.P.; Decowski, M.P.; Hogenbirk, E.; Tiseni, A. [Nikhef and the University of Amsterdam, Science Park, Amsterdam (Netherlands); Agostini, F. [INFN-Laboratori Nazionali del Gran Sasso (Italy); Gran Sasso Science Institute, L' Aquila (Italy); University of Bologna, Department of Physics and Astrophysics, Bologna (Italy); INFN-Bologna (Italy); Alfonsi, M.; Geis, C.; Grignon, C.; Oberlack, U.; Scheibelhut, M.; Schindler, S. [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Amaro, F.D.; Cardoso, J.M.R.; Lopes, J.A.M.; Orrigo, S.E.A.; Santos, J.M.F. dos; Silva, M. [University of Coimbra, Department of Physics, Coimbra (Portugal); Arneodo, F.; Benabderrahmane, M.L.; Di Giovanni, A.; Maris, I. [New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Barrow, P.; Baudis, L.; Franco, D.; Galloway, M.; Kessler, G.; Kish, A.; Mayani, D.; Pakarha, P.; Piastra, F.; Wei, Y.; Wulf, J. [Physik-Institut, University of Zurich, Zurich (Switzerland); Bauermeister, B. [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Stockholm University, AlbaNova, Oskar Klein Centre, Department of Physics, Stockholm (Sweden); Berger, T.; Brown, E.; Piro, M.C. [Rensselaer Polytechnic Institute, Department of Physics, Applied Physics and Astronomy, Troy, NY (United States); Bruenner, S.; Cichon, D.; Eurin, G.; Hasterok, C.; Lindemann, S.; Lindner, M.; Undagoitia, T.M.; Pizzella, V.; Rauch, L.; Rupp, N.; Schreiner, J.; Simgen, H. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Bruno, G.; Gallo Rosso, A.; Molinario, A. [INFN-Laboratori Nazionali del Gran Sasso (Italy); Gran Sasso Science Institute, L' Aquila (Italy); Budnik, R.; Duchovni, E.; Itay, R.; Landsman, H.; Lellouch, D.; Levinson, L.; Manfredini, A.; Priel, N. [Weizmann Institute of Science, Department of Particle Physics and Astrophysics, Rehovot (Israel); Buetikofer, L.; Coderre, D.; Kaminsky, B.; Schumann, M.; Sivers, M. v. [Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Calven, J.; Conrad, J.; Ferella, A.D.; Pelssers, B. [Stockholm University, AlbaNova, Oskar Klein Centre, Department of Physics, Stockholm (Sweden); Cervantes, M.; Lang, R.F.; Masson, D.; Pienaar, J.; Reichard, S.; Reuter, C. [Purdue University, Department of Physics and Astronomy, West Lafayette, IN (United States); Cussonneau, J.P.; Diglio, S.; Le Calloch, M.; Masbou, J.; Micheneau, K.; Persiani, R.; Thers, D. [Universite de Nantes, SUBATECH, Ecole des Mines de Nantes, CNRS/In2p3, Nantes (France); Di Gangi, P.; Garbini, M.; Massoli, F.V.; Sartorelli, G.; Selvi, M. [University of Bologna, Department of Physics and Astrophysics, Bologna (Italy); INFN-Bologna (Italy); Fei, J.; Ni, K.; Ye, J. [University of California, Department of Physics, San Diego, CA (United States); Fieguth, A.; Huhmann, C.; Murra, M.; Rosendahl, S.; Weinheimer, C. [Westfaelische Wilhelms-Universitaet Muenster, Institut fuer Kernphysik, Muenster (Germany); Fulgione, W. [INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, L' Aquila (Italy); INFN-Torino (Italy); Osservatorio Astrofisico di Torino, Torino (Italy); Grandi, L.; Saldanha, R.; Shockley, E.; Upole, N. [University of Chicago, Department of Physics and Kavli Institute of Cosmological Physics, Chicago, IL (United States); Lin, Q. [Laboratori Nazionali del Gran Sasso, Assergi (Italy); Meng, Y.; Stein, A.; Wang, H. [University of California, Physics and Astronomy Department, Los Angeles, CA (United States); Miguez, B.; Trinchero, G. [INFN-Torino (Italy); Osservatorio Astrofisico di Torino, Torino (Italy); Naganoma, J.; Shagin, P. [Rice University, Department of Physics and Astronomy, Houston, TX (United States); Lavina, L.S. [LPNHE, Universite Pierre et Marie Curie, Universite Paris Diderot, CNRS/IN2P3, Paris (France); Tunnell, C. [Nikhef and the University of Amsterdam, Science Park, Amsterdam (Netherlands); University of Chicago, Department of Physics and Kavli Institute of Cosmological Physics, Chicago, IL (United States); Cristescu, I. [Karlsruhe Institute of Technology, Tritium Laboratory Karlsruhe, Eggenstein-Leopoldshafen (Germany); Collaboration: XENON Collaboration

2017-05-15

The XENON1T experiment aims for the direct detection of dark matter in a detector filled with 3.3 tons of liquid xenon. In order to achieve the desired sensitivity, the background induced by radioactive decays inside the detector has to be sufficiently low. One major contributor is the β-emitter {sup 85}Kr which is present in the xenon. For XENON1T a concentration of natural krypton in xenon {sup nat}Kr/Xe < 200 ppq (parts per quadrillion, 1 ppq = 10{sup -15} mol/mol) is required. In this work, the design, construction and test of a novel cryogenic distillation column using the common McCabe-Thiele approach is described. The system demonstrated a krypton reduction factor of 6.4 . 10{sup 5} with thermodynamic stability at process speeds above 3 kg/h. The resulting concentration of {sup nat}Kr/Xe < 26 ppq is the lowest ever achieved, almost one order of magnitude below the requirements for XENON1T and even sufficient for future dark matter experiments using liquid xenon, such as XENONnT and DARWIN. (orig.)

A novel approach to measure the electric dipole moment of the isotope 129-Xe

Directory of Open Access Journals (Sweden)

Kuchler F.

2014-03-01

Full Text Available Permanent electric dipole moments (EDM of fundamental systems are promising systems to find new CP violation beyond the Standard Model. Our EDM experiment is based on hyper-polarized liquid xenon droplets of sub-millimeter size on a micro-fabricated structure, placed in a low-field NMR setup. Implementation of rotating electric fields enables a conceptually new EDM measurement technique, allowing thorough investigation of systematic effects. Still, a Ramsey-type spin precession experiment with static electric field can be realized at similar sensitivity within the same setup. Employing superconducting pick-up coils and highly sensitive LTc-SQUIDs, a large array of independent measurements can be performed simultaneously. With our approach we aim to finally increase the sensitivity on the EDM of 129Xe by more than three orders of magnitude.

Dynamic adsorption property of xenon on activated carbon and carbon molecular sieves

International Nuclear Information System (INIS)

Feng Shujuan; Zhou Guoqing; Jin Yuren; Zhou Chongyang

2010-01-01

In order to select well adsorptive xenon adsorbent, the dynamic adsorption property of xenon on activated carbon and carbon molecular sieves (CMS) was studied by measuring the xenon dynamic adsorption coefficient as a function velocity of gas, temperature, carrier gas, pressure and concentration of CO 2 . The results show that the highest value of xenon dynamic adsorption coefficient is on CMS1, and the second highest value is on CMS2; when the xenon concentration is less than 10 -5 mol/L or concentration of CO 2 is less than 5 x 10 -5 mol/L, the xenon dynamic adsorption coefficient nearly keeps constant at the specific experimental flow rate. Then the xenon dynamic adsorption coefficient would vary when it was mixed with different kind of carrier gas and become less at more than 5 x 10 -5 mol/L concentration of CO 2 . And the maximal effect factors are temperature and pressure. Therefore, the feasible measures to improve the xenon capability are to cool the adsorbent and increase adsorption pressure. (authors)

Observation of a barium xenon exciplex within a large argon cluster.

Science.gov (United States)

Briant, M; Gaveau, M-A; Mestdagh, J-M

2010-07-21

Spectroscopic measurements provide fluorescence and excitation spectra of a single barium atom codeposited with xenon atoms on argon clusters of average size approximately 2000. The spectra are studied as a function of the number of xenon atoms per cluster. The excitation spectrum with approximately 10 xenon atoms per cluster is qualitatively similar to that observed when no xenon atom is present on the cluster. It consists of two bands located on each side of the 6s6p (1)P-6s(2) (1)S resonance line of the free barium. In contrast, the fluorescence spectrum differs qualitatively since a barium-xenon exciplex is observed, which has no counterpart in xenon free clusters. In particular an emission is observed, which is redshifted by 729 cm(-1) with respect to the Ba(6s6p (1)P-6s(2) (1)S) resonance line.

Core level photoelectron spectroscopy probed heterogeneous xenon/neon clusters

International Nuclear Information System (INIS)

Pokapanich, Wandared; Björneholm, Olle; Öhrwall, Gunnar; Tchaplyguine, Maxim

2017-01-01

Binary rare gas clusters; xenon and neon which have a significant contrariety between sizes, produced by a co-expansion set up and have been studied using synchrotron radiation based x-ray photoelectron spectroscopy. Concentration ratios of the heterogeneous clusters; 1%, 3%, 5% and 10% were controlled. The core level spectra were used to determine structure of the mixed cluster and analyzed by considering screening mechanisms. Furthermore, electron binding energy shift calculations demonstrated cluster aggregation models which may occur in such process. The results showed that in the case of low mixing ratios of 3% and 5% of xenon in neon, the geometric structures exhibit xenon in the center and xenon/neon interfaced in the outer shells. However, neon cluster vanished when the concentration of xenon was increased to 10%. - Highlights: • Co-expansion setup is suitable for producing binary Xe/Ne clusters. • Appropriate temperature, pressure, and mixing ratios should be strictly controlled. • Low mixing ratio, Xe formed in the core and Xe/Ne interfacing in the outer shell. • High mixing ratio, only pure Xe clusters were detected.

Radon removal from gaseous xenon with activated charcoal

Energy Technology Data Exchange (ETDEWEB)

Abe, K.; Hieda, K.; Hiraide, K.; Hirano, S.; Kishimoto, Y.; Kobayashi, K.; Koshio, Y. [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Kamioka, Hida, Gifu 506-1205 (Japan); Liu, J.; Martens, K. [Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Moriyama, S. [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Kamioka, Hida, Gifu 506-1205 (Japan); Nakahata, M. [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Kamioka, Hida, Gifu 506-1205 (Japan); Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Nishiie, H.; Ogawa, H.; Sekiya, H.; Shinozaki, A. [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Kamioka, Hida, Gifu 506-1205 (Japan); Suzuki, Y. [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Kamioka, Hida, Gifu 506-1205 (Japan); Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Takachio, O.; Takeda, A.; Ueshima, K.; Umemoto, D. [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Kamioka, Hida, Gifu 506-1205 (Japan); and others

2012-01-01

Many low background experiments using xenon need to remove radioactive radon to improve their sensitivities. However, no method of continually removing radon from xenon has been described in the literature. We studied a method to remove radon from xenon gas through an activated charcoal trap. From our measurements we infer a linear relationship between the mean propagation velocity v{sub Rn} of radon and v{sub Xe} of xenon in the trap with v{sub Rn}/v{sub Xe}=(0.96{+-}0.10) Multiplication-Sign 10{sup -3} at -85 Degree-Sign C. As the mechanism for radon removal in this charcoal trap is its decay, knowledge of this parameter allows us to design an efficient radon removal system for the XMASS experiment. The verification of this system found that it reduces radon by a factor of 0.07, which is in line with its expected average retention time of 14.8 days for radon.

Damage of copper by low energy xenon ions

International Nuclear Information System (INIS)

Babad-Zakhryapin, A.A.; Popenko, V.A.

1988-01-01

Changes in the copper crystal structure bombarded by xenon ions with 30-150 eV energy are studied. Foils of MOb copper mark, 10 mm in diameter and 100 μm thickness, are irradiated. The initial specimens are annealed in vacuum during 1 h at 900 K temperature. The specimens are bombarded by xenon ions in a water-cooled holder. A TE-O type accelerator serves as a xenon ion source. The ion energy varies within 30 to 150 eV range. The ion flux density is 8x10 16 ion/(cm 2 xs). It is shown that crystal structure variations at deep depths are observed not only at high (>1 keV), but at low ion energies down to several dozens of electronvolt as well. The crystal structure variation on copper irradiation by xenon ions with 30-150 eV energy is followed by formation of defects like dislocation loops, point defects in the irradiated target bulk

New features of nuclear excitation by {alpha} particles scattering; Nouveaux aspects de l'excitation nucleaire par diffusion de particules {alpha}

Energy Technology Data Exchange (ETDEWEB)

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

1962-07-01

Inelastic scattering of medium energy a particles by nuclei is known to excite preferentially levels of collective character. We have studied the scattering of isotopically enriched targets of Ca, Fe, Ni, Cu, Zn. In part I, we discuss the theoretical features of the interaction. In part II, we describe the experimental procedure. Results are presented and analysed in part III. {alpha} particles scattering by Ca{sup 40} is showed to excite preferentially odd parity levels. In odd nuclei we have observed multiplets due to the coupling of the odd nucleon with the even-even core vibrations. For even-even nuclei, a few levels are excited with lower cross-sections between the well-known first 2{sup +} and 3{sup -} states. Some could be members of the two phonon quadrupole excitation and involve a double nuclear excitation process. (author) [French] On sait que la diffusion inelastique des particules alpha de moyenne energie excite preferentiellement des niveaux de caractere collectif. Nous avons etudie la diffusion des particules alpha de 44 MeV du cyclotron de Saclay par des isotopes separes de Ca, Fe, Ni, Cu, Zn. Dans la premiere partie nous exposons les theories de cette interaction. Dans la seconde nous decrivons le systeme experimental. Les resultats sont donnes dans la troisieme partie. Nous montrons que les niveaux excites preferentiellement pour {sup 40}Ca par diffusion ({alpha},{alpha}') sont de parite negative. Dans les noyaux pair-impair nous avons observe des multiplets dus au couplage du nucleon celibataire avec les vibrations du coeur pair-pair. Pour les noyaux pair-pair nous avons pu etudier entre le premier niveau 2{sup +} et le niveau 3{sup -} deja bien connus certains etats plus faiblement excites. Il semble qu'ils sont dus a une excitation quadrupolaire a deux phonons et impliquent un processus de double excitation nucleaire. (auteur)

Siloette, Siloe mock-up; Siloette, modele nucleaire de siloe

Energy Technology Data Exchange (ETDEWEB)

Delcroix, V; Jeanne, G; Mitault, G; Schulhof, P [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1964-07-01

Siloette is the Siloe mock-up. The main installations are described: various tanks, building, auxiliaries, control systems... Precis ions are given about precautions taken for using spent fuel elements. (authors) [French] Siloette est le modele nucleaire de SILOE. On decrit ses diverses installations: bassins, batiments, auxiliaires, controle... Des precisions sont donnees sur les precautions prises pour y utiliser des elements uses. (auteurs)

Contribution to the study of {beta} disintegration and of nuclear structure using experiments on certain {beta}-{gamma} cascades: 198{sub Au}, 86{sub Rb}, 170{sub Tm}; Contribution a l'etude de la desintegration beta et a l'etude de la structure nucleaire a l'aide d'experiences sur certaines cascades beta-gamma: 198{sub Au}, 86{sub Rb}, 170{sub Tm}

Energy Technology Data Exchange (ETDEWEB)

Lachkar, J [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes; Paris-11 Univ., fabulte des Sciences 91 - Orsay (France)

1969-07-01

{beta}{gamma} directional angular correlations and shapes of inner beta spectra leading to the first excited level of the final nucleus enable one to determine the nuclear matrix elements typical of the {beta} transition. In the three observed first forbidden cases: {sup 170}Tm, {sup 86}Rb, {sup 198}Au, these matrix elements do not confirm the independent shell model theory. Other hypotheses are then suggested and discussed. (author) [French] Les experiences de correlation angulaire {beta}{gamma} et l'etude du spectre {beta} conduisant au premier niveau excite du noyau final permettent de determiner les elements de matrices nucleaires caracteristiques de cette transition. Dans les trois cas etudies (transitions une fois interdites): {sup 170}Tm, {sup 86}Rb, {sup 198}Au, ces elements de matrices ne peuvent etre retrouves a l'aide du modele en couches et a particules independantes. D'autres hypotheses sont alors emises et discutees. (auteur)

Weird muonium diffusion in solid xenon

International Nuclear Information System (INIS)

Storchak, V.G.; Kirillov, B.F.; Pirogov, A.V.

1992-09-01

Muon and muonium spin rotation and relaxation parameters were studied in liquid and solid xenon. The small diamagnetic fraction (∼ 10%) observed in condensed xenon is believed to be Xeμ + . The muonium hyperfine frequency was measured for the first time in liquid Xe and was found to be in agreement with the vacuum value. A nonmonotonic temperature dependence of the muonium relaxation rate probably indicates that muonium diffusion in solid Xe is of quantum nature. 16 refs., 3 figs

Public debate about the EPR nuclear power plant at Flamanville; Debat public sur la centrale nucleaire EPR a Flamanville

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-07-01

The project of building of he EPR reactor at Flamanville (Manche, France) has been submitted to the public debate. This document includes a presentation of the project and of the rules of the public debate, a synthesis of the file made by the prime contractor (EDF), a synthesis of the collective book of national actors concerned by the project (a group of associations for environment protection, Areva company, the ministries of economy and ecology, Global Chance, association of pro-nuclear ecologists (AEPN), 'Sortir du Nucleaire' (out-of nuclear) network, group of scientists for the information about nuclear (GSIEN), association for the promotion of the Flamanville site (Proflam), French nuclear energy society (SFEN) in association with 'Sauvons le Climat' (let's save climate), regional collective association 'EPR non merci, ni ailleurs, ni ici' (EPR, no thanks, neither elsewhere, nor here), NegaWatt), and 5 detailed books of actors: ACRO (association for the control of radioactivity in Western France), CFDT and CGT syndicates, the economic and social council of Basse Normandie region, and Proflam. (J.S.)

Public debate about the EPR nuclear power plant at Flamanville; Debat public sur la centrale nucleaire EPR a Flamanville

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-07-01

The project of building of he EPR reactor at Flamanville (Manche, France) has been submitted to the public debate. This document includes a presentation of the project and of the rules of the public debate, a synthesis of the file made by the prime contractor (EDF), a synthesis of the collective book of national actors concerned by the project (a group of associations for environment protection, Areva company, the ministries of economy and ecology, Global Chance, association of pro-nuclear ecologists (AEPN), 'Sortir du Nucleaire' (out-of nuclear) network, group of scientists for the information about nuclear (GSIEN), association for the promotion of the Flamanville site (Proflam), French nuclear energy society (SFEN) in association with 'Sauvons le Climat' (let's save climate), regional collective association 'EPR non merci, ni ailleurs, ni ici' (EPR, no thanks, neither elsewhere, nor here), NegaWatt), and 5 detailed books of actors: ACRO (association for the control of radioactivity in Western France), CFDT and CGT syndicates, the economic and social council of Basse Normandie region, and Proflam. (J.S.)

Study of regional lung ventilation and perfusion by xenon 133

International Nuclear Information System (INIS)

Lombard, Yves.

1976-01-01

The present work consists of a regional lung exploration after injection of xenon 133, dissolved in physiological serum, followed a few minutes later by that of 99m Tc-labelled serumalbumin microspheres. The aim is three fold: first of all to study perfusion and ventilation by xenon 133, next to compare the results obtained after xenon 133 and 99 m Tc-labelled microsphere injection, lastly to establish the value of the technique and its routine application. This examination has not solved all problems of lung exploration by xenon 133. For example we deliberately kept to intraveinous injection of the gas dissolved in physiological serum, leaving aside the breathing test. Xenon 133 scintigraphy in our opinion will not tend to replace 99m Tc-labelled microsphere scintigraphy, which has irreplaceable morphological qualities, but will serve as an excellent complement. The basic advantage of xenon 133 is the regional ventilation estimate it provides allowing any anomaly of the lung parenchyma to be located immediately or conversely the functional value of the healthy lung to be established with a view to a surgical removal of a diseased zone [fr

Isotopic composition of primary xenon and the fission of Pu-244

Energy Technology Data Exchange (ETDEWEB)

Levskii, L K

1983-05-01

The hypothesis that the origin of xenon on earth is due to the fission of uranium and/or transuranium elements is examined. The isotopic composition of primary xenon on earth is calculated using a model (Levskii, 1980) of the isotopic composition of rare gases which is based on the hypothesis of the heterogeneity of the isotopic composition of the elements of the solar system. The isotopic composition of fission-produced xenon in the atmosphere and solid earth is determined to correspond to the abundance of xenon isotopes as a result of the spontaneous fission of Pu-244 (half-life of 8.2 x 10 to the 7th years). The amount of fission-produced xenon in the atmosphere is shown to amount to about 30 percent (Xe-136). Under certain conditions, the degree of the degassing of the solid earth for xenon is 25 percent, which corresponds to a ratio of Kr-84/Xe-130 45 for the earth as a whole.

Production of Xenon Compounds by the Beta Decay of Iodine in Iodine Compounds; Production de Composes du Xenon par Desintegration Beta de l'Iode dans les Composes Iodes; 041f 0420 041e 0418 0417 0412 041e 0414 0421 0422 0412 041e 0421 041e 0415 0414 0418 041d 0415 041d 0418 0419 041a 0421 0415 041d 041e 041d 0410 041f 041e 0421 0420 0415 0414 0421 0422 0412 041e 041c 0411 0415 0422 0410 - 0420 0410 0421 041f 0410 0414 0410 0419 041e 0414 0410 0412 0419 041e 0414 0418 0421 0422 042b 0425 0421 041e 0415 0414 0418 041d 0415 041d 0418 042f 0425 ; Produccion de Compuestos de Xenon por Desintegracion Beta del Yodo de Compuestos Yodados

Energy Technology Data Exchange (ETDEWEB)

Perlow, G. J.; Perlow, M. R. [Argonne National Laboratory, Argonne, IL (United States)

1965-04-15

than in XeF{sub 4}. Here ICl{sup -}{sub 4} -{yields} XeCl{sub 4}. Using aligned crystals of KICl{sub 4} * H{sub 2}O and making quantitative intensity measurements it was established that the square planar structure of ICl{sub 4}{sup -} is preserved in the transition to XeCl{sub 4} and that XeCl{sub 2} and Xe{sup 0} are not formed in the reaction in detectable amounts. = With Na{sub 3}H{sub 2} I{sup 131}O{sub 6} as source we observed the effect in Xe{sup 131}. Comparing XeF{sub 4} spectra in both isotopes calibrated the splitting in Xe{sup 129} and enabled quantitative comparison of XeF{sub 4} and XeCl{sub 4} with ICI{sub 4}{sup -}, and of XeO{sub 3} with IO{sub 3}{sup -}. The unsplit KIO{sub 4} spectrum implies that the tetrahedral ligand environment of the iodine is preserved in the resulting XeO{sub 4}. Similarly, the paraperiodate result is consistent with preservation of its octahedral environment. (author) [French] On sait que la plupart des processus de desintegration beta ne provoquent aucune modification dans le nombre d'electrons de l'atome contenant le noyau en desintegration. Dans la desintegration beta {sup 129}I -{yields} {sup 129}Xe intervenant dans un compose iode, la structure et la gecmetrie electroniques se pretent souvent a la formation d'un compose de xenon ayant les memes coordinats. Les auteurs ont decouvert et etudie ce phenomene en utilisant l'effet Moessbauer dans {sup 129}Xe. L'etat initialement excite dans {sup 129}Xe se caracterise par J{sup {pi}} = 3+/2, T{sub Vulgar-Fraction-One-Half} = 10{sup -9} * s, et se situe a 40 keV au-dessus de l'etat fondamental de 1+/2. Il est peuple par une desintegration a partir de {sup 129}1 (1,6 * 10{sup 6} a). L'effet Moessbauer des rayons gamma de 40 keV peut etre aisement observe avec diverses sources et absorbeurs dans des experiences faites a 4,2 Degree-Sign K. Lorsqu'on utilise le deplacement Doppler pour l'exploration du spectre, le dedoublement quadrupolaire electrique de l'etat excite donne lieu a

Europe CERN recherche - Pret de 300 millions d'euros de la BEI pour l'accelerateur de particules

CERN Multimedia

2002-01-01

"La Banque europeenne d'investissement (BEI) va preter 300 millions d'euros pour financer la phase finale de la construction du grand accelerateur de particules LHC (Large Hadron Collider) du CERN, a indique jeudi l'organisation europeenne pour la recherche nucleaire" (1/2 page).

Health problems raised by the elimination of radioactive wastes and nuclear accidents; Problemes sanitaires poses par l'elimination des dechets radioactifs et par les accidents nucleaires

Energy Technology Data Exchange (ETDEWEB)

Jammet, H; Mechali, D; Dousset, M [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1964-07-01

residus radioactifs produits par les installations nucleaires. L'evaluation du risque encouru par les populations et la fixation des limites admissibles pour les rejets ne peuvent resulter que d'une connaissance exacte du cheminement des radioelements rejetes, depuis leur source d'emission jusqu'a l'homme. L'incorporation des radioelements dans les chaines alimentaires constitue le premier risque a prendre en consideration. Les facteurs de passage doivent etre envisages, dans toutes les etapes de cette transmission, qu'elles interessent les milieux physiques ou les milieux proprement biologiques, du fait de leur continuite et de leur interdependance. Enfin, les donnees de caractere socio-economique et dietetique doivent etre recueillies pour conduire a une evaluation des risques et des niveaux admissibles reposant non sur des donnees theoriques mais sur des bases concretes et experimentales. Le risque d'accidents nucleaires dans l'industrie atomique, bien que de probabilite tres reduite, doit etre pris en consideration du fait de la gravite de leurs consequences. Les problemes sanitaires se posent d'une part dans le domaine de l'hygiene professionnelle, d'autre part dans celui de l'hygiene publique. Le premier domaine implique un risque double: d'irradiation et de contamination. Le domaine public n'est soumis essentiellement qu'au risque de contamination par les substances radioactives liberees accidentellement dans le milieu. Les etudes sanitaires a mener dans ce domaine comprennent, de ce fait, les recherches sur la therapeutique des irradiations ou des contaminations mais aussi celles relatives au transfert des radioelements depuis l'installation accidentee jusqu'a l'homme, principalement a travers les chaines alimentaires, dans leurs composantes physiques comme dans leurs composantes biologiques. De telles etudes sont a la base des decisions d'ordre sanitaire qu'il conviendrait de prendre dans le cas d'un accident. (auteurs)

Transportable Xenon Laboratory (TXL-1) Operations Manual

Energy Technology Data Exchange (ETDEWEB)

Thompson, Robert C.; Stewart, Timothy L.; Willett, Jesse A.; Woods, Vincent T.

2011-03-07

The Transportable Xenon Laboratory Operations Manual is a guide to set up and shut down TXL, a fully contained laboratory made up of instruments to identify and measure concentrations of the radioactive isotopes of xenon by taking air samples and analyzing them. The TXL is housed in a standard-sized shipping container. TXL can be shipped to and function in any country in the world.

Health physics problems in the context of the development of industrial uses of nuclear energy; Les problemes de radioprotection devant le developpement de l'utilisation industrielle de l'energie nucleaire

Energy Technology Data Exchange (ETDEWEB)

Duhamel, F; Menoux, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

fate of radioactive ions in the hydrosphere may be determined. - experiments and studies linked with the possibilities for disposal a underground storage of wastes. All these studies cover a complementary field, that of radioprotection, which forms the necessary link between nuclear safety proper, which concerns the actual operation of nuclear installations and medical supervision which directly concerns the health of the individual and the population. At the same time each one of the Health Physics disciplines possesses an independence which increases their efficiency on the safety level. (authors) [French] Le developpement de l'utilisation industrielle de l'energie nucleaire a mis l'accent sur la necessite de promouvoir une doctrine rationnelle et coherente en matiere de securite des installations atomiques et plus particulierement en matiere de securite des sites nucleaires. Le but principal de la securite est de diminuer, voire d'annuler les risques d'irradiation ou de contamination des travailleurs et de la population, consecutifs au fonctionnement normal ou accidentel des installations. La securite est obtenue par la mise en oeuvre d'un ensemble complexe de moyens. Parmi ces moyens les auteurs considerent essentiellement ceux qui presentent une certaine independance a l'egard du type d'installation: moyens d'alerte et de mesure et leur mise en oeuvre - preparation psychologique et technique des individus - evaluation de la capacite d'un site a absorber les rejets radioactifs sans dommage pour la population. Il est clair en effet que les consequences d'un accident sont diminuees par l'augmentation de la valeur des moyens de surveillance, de mesure et d'alerte, l'elevation du niveau technique et l'entrainement du personnel, l'education de la population. Ceci est particulierement vrai aupres d'une installation nucleaire ou l'etude des dangers presente un caractere abstrait et ou les moyens technologiques de protection sont multiples et complexes. Les etudes de

Signal yields, energy resolution, and recombination fluctuations in liquid xenon

Science.gov (United States)

Akerib, D. S.; Alsum, S.; Araújo, H. M.; Bai, X.; Bailey, A. J.; Balajthy, J.; Beltrame, P.; Bernard, E. P.; Bernstein, A.; Biesiadzinski, T. P.; Boulton, E. M.; Bramante, R.; Brás, P.; Byram, D.; Cahn, S. B.; Carmona-Benitez, M. C.; Chan, C.; Chiller, A. A.; Chiller, C.; Currie, A.; Cutter, J. E.; Davison, T. J. R.; Dobi, A.; Dobson, J. E. Y.; Druszkiewicz, E.; Edwards, B. N.; Faham, C. H.; Fiorucci, S.; Gaitskell, R. J.; Gehman, V. M.; Ghag, C.; Gibson, K. R.; Gilchriese, M. G. D.; Hall, C. R.; Hanhardt, M.; Haselschwardt, S. J.; Hertel, S. A.; Hogan, D. P.; Horn, M.; Huang, D. Q.; Ignarra, C. M.; Ihm, M.; Jacobsen, R. G.; Ji, W.; Kamdin, K.; Kazkaz, K.; Khaitan, D.; Knoche, R.; Larsen, N. A.; Lee, C.; Lenardo, B. G.; Lesko, K. T.; Lindote, A.; Lopes, M. I.; Manalaysay, A.; Mannino, R. L.; Marzioni, M. F.; McKinsey, D. N.; Mei, D.-M.; Mock, J.; Moongweluwan, M.; Morad, J. A.; Murphy, A. St. J.; Nehrkorn, C.; Nelson, H. N.; Neves, F.; O'Sullivan, K.; Oliver-Mallory, K. C.; Palladino, K. J.; Pease, E. K.; Phelps, P.; Reichhart, L.; Rhyne, C.; Shaw, S.; Shutt, T. A.; Silva, C.; Solmaz, M.; Solovov, V. N.; Sorensen, P.; Stephenson, S.; Sumner, T. J.; Szydagis, M.; Taylor, D. J.; Taylor, W. C.; Tennyson, B. P.; Terman, P. A.; Tiedt, D. R.; To, W. H.; Tripathi, M.; Tvrznikova, L.; Uvarov, S.; Verbus, J. R.; Webb, R. C.; White, J. T.; Whitis, T. J.; Witherell, M. S.; Wolfs, F. L. H.; Xu, J.; Yazdani, K.; Young, S. K.; Zhang, C.; LUX Collaboration

2017-01-01

This work presents an analysis of monoenergetic electronic recoil peaks in the dark-matter-search and calibration data from the first underground science run of the Large Underground Xenon (LUX) detector. Liquid xenon charge and light yields for electronic recoil energies between 5.2 and 661.7 keV are measured, as well as the energy resolution for the LUX detector at those same energies. Additionally, there is an interpretation of existing measurements and descriptions of electron-ion recombination fluctuations in liquid xenon as limiting cases of a more general liquid xenon recombination fluctuation model. Measurements of the standard deviation of these fluctuations at monoenergetic electronic recoil peaks exhibit a linear dependence on the number of ions for energy deposits up to 661.7 keV, consistent with previous LUX measurements between 2 and 16 keV with 3H. We highlight similarities in liquid xenon recombination for electronic and nuclear recoils with a comparison of recombination fluctuations measured with low-energy calibration data.

Muonium formation in xenon and argon up to 60 atmospheres

International Nuclear Information System (INIS)

Kempton, J.R.; Senba, M.; Arseneau, D.J.; Gonzalez, A.C.; Pan, J.J.; Tempelmann, A.; Garner, D.M.; Fleming, D.G.

1991-01-01

Results of muon polarization studies in xenon and argon up to 60 atm are reported. In argon for pressures up to 10 atm, the muon polarization is best explained by an epithermalcharge exchange model. Above this pressure, the decrease in P D and increase in P L are ascribed to charge neutralization and spin exchange reactions, respectively, in the radiolysis track. Measurements with Xe/He mixtures with a xenon pressure of 1 atm indicate that the lost polarization in the pure xenon at this pressure is due to inefficient moderation of the muon. As the pressure in pure xenon is increased above 10 atm, we find that P L remains roughly constant and P D begins to increase. The lost fraction may be due to the formation of a XeMu Van der Waals type complex, while P D is ascribed to XeMu + formation. This suggests that spur processes appear to be less important in xenon that in argon. (orig.)

Associative memories in nuclear physics; Les memoires associatives en physique nucleaire

Energy Technology Data Exchange (ETDEWEB)

Blanca, E; Carriere, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-07-01

Experiments in nuclear physics involve the use of large size 'memories'. After showing the difficulties arising from the use of such memories, the authors give the principles of the various programming methods which make it possible to operate the memories associatively thus benefiting from a reduction in size and better operational conditions. They attempt to estimate the shape and dimensions of an associative memory with cable connections which could be designed specially for nuclear research, contrary to those actually in service. (authors) [French] Les experiences de physique nucleaire necessitent l'emploi de 'memoires' de grandes dimensions. Apres avoir montre les inconvenients que presente l'utilisation de telles memoires, les auteurs exposent les principes des diverses methodes de programmation qui permettent d'assurer un fonctionnement des memoires sur le mode associatif donc une reduction de leurs dimensions et un meilleur usage. Ils tentent d'evaluer le format d'une memoire associative cablee qui, contrairement a celles qui existent actuellement, serait prevue specialement pour l'experimentation nucleaire. (auteurs)

Converging xenon shock waves driven by megagauss magnetic fields

International Nuclear Information System (INIS)

Shearer, J.W.; Steinberg, D.J.

1986-07-01

We attempted to implode a conducting metal linear at high velocity, and our failure to do so led to switching, or rapidly transferring the field from pushing an aluminum conductor to snow-plowing a half-atmosphere of xenon gas. We successfully initiated convergent xenon gas shocks with the use of a magnetohydrodynamic switch and coaxial high-explosive, flux-compression generators. Principal diagnostics used to study the imploding xenon gas were 133 Xe radioactive tracers, continuous x-ray absorption, and neutron output. We compressed the xenon gas about five to sixfold at a velocity of 10 cm/μs at a radius of 4 cm. The snowplow efficiency was good; going from 13- to 4-cm radius, we lost only about 20% of the mass. The temperature of the imploded sheath was determined by mixing deuterium with the xenon and measuring the neutron output. Using reasonable assumptions about the amount, density, and uniformity of the compressed gas, we estimate that we reached temperatures as high as 155 eV. Energy-loss mechanisms that we encountered included wall ablation and Taylor instabilities of the back surface

Measurement of xenon reactivity in the reactor of the nuclear ship 'MUTSU'

International Nuclear Information System (INIS)

Itagaki, Masafumi; Miyoshi, Yoshinori; Gakuhari, Kazuhiko; Okada, Noboru.

1993-01-01

This report deals with the measurement of reactivity changes caused by the increase and decrease of xenon concentration in the reactor core of the nuclear ship 'MUTSU' after a change from long-term operation at 70 % to zero power. The change in xenon reactivity was compensated by control-rod movements and the compensated reactivity was measured using a digital reactivity meter. The xenon override peak was recognized five and half hours after the start of power reduction. The equilibrium and peak reactivities of xenon were estimated by reading the initial and peak values of a theoretical curve which was fitted to the measured variation in xenon reactivity. The xenon reactivity results obtained by the present method can be considered to be accurate since no control-rod worth data were used and the measured quantity was the reactivity itself. (author)

Piles used for the nuclear control of materials; Empilements pour le controle nucleaire des materiaux

Energy Technology Data Exchange (ETDEWEB)

Raievski, V; Sautiez, B; Bailly du Bois, B; Tretiakoff, O; Thome, P; Vidal, R; Koppel Martelly, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

The devices which make it possible to check on the nuclear qualities of the materials used in reactor construction are described. These verifications bear on substantial masses of materials, following the last stage of their machining. The components found in all these are a graphite pile into which the material to be investigated is inserted, a source of neutrons made up of an Ra-Be system, and a proportional BF{sub 3} counter. The devices described here bear on checking graphite, beryllium oxide and uranium absorption, as well as on a verification of the {sup 235}U content of fuel elements. (author)Fren. [French] On decrit des dispositifs permettant de controler les qualites nucleaires de materiaux utilises dans la construction des piles. Ce controle s'effectue sur des masses importantes de materiaux apres la phase finale d'usinage. Ces dispositifs ont en commun un empilement de graphite recevant le materiau a etudier, une source de neutrons de Ra-Be et un compteur proportionnel a BF{sub 3}. Les dispositifs decrits concernent le controle de l'absorption du graphite, de la glucine et de l'uranium, ainsi que le controle de la teneur en {sup 235}U des elements de combustion. (auteur)

Contribution to the study of the evolution of radiation induced He in Be O; Etudes sur l'evolution de l'helium produit par reactions nucleaires dans l'oxyde de beryllium

Energy Technology Data Exchange (ETDEWEB)

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

1966-11-15

The purpose of this work in-pile investigation of He formed by (n, 2n) and (n, {alpha}) nuclear reactions, released from irradiated BeO, in the temperature range 1000 - 1350 deg. C. The experimental results show that, for an instantaneous neutron fast flux of 10{sup 13} n cm{sup -2} sec{sup -1}, an equilibrium is attempted, after several days, for a part lower than 20 per cent of the quantity of He formed, theoretically calculated from the neutron cross sections of nuclear reactions, and from the analytical form of the neutron fast flux, releases from the solid. The validity of the values of calculated helium and the gas chromatographic analytical method are also verified by dissolution of the BeO pellets in cryolite. A new fast neutron flux measuring method may be so defined. The discussion of the experimental results enables to establish that the processus of He release is characterized by two phenomena: the first one which controls the release of He atoms out of the solid and the second which reveals a capture processus, connected to the irradiation and probably due to the vacancies induced in the lattice. (author) [French] On etudie en pile le degagement de l'helium forme par reactions nucleaires (n, 2 n) et (n, {alpha}) dans l'oxyde de beryllium irradie entre 1000 et 1350 deg. C. Les resultats experimentaux montrant que, pour un flux rapide instantane de 10{sup 13} n{sub r} cm{sup -2} s{sup -1}, on aboutit, au bout de quelques jours, a un etat d'equilibre pour lequel une partie, inferieure a 20 pour cent de la quantite d'helium forme, calculee theoriquement a partir des sections efficaces des reactions nucleaires et de la forme analytique du flux rapide, s'echappe du solide. On verifie egalement par dissolution des echantillons de BeO dans la cryolithe la validite du calcul de l'helium et de la methode de dosage par chromatographie en phase gazeuse. On peut ainsi definir une methode nouvelle de mesure des flux rapides. La

Health problems raised by the elimination of radioactive wastes and nuclear accidents; Problemes sanitaires poses par l'elimination des dechets radioactifs et par les accidents nucleaires

Energy Technology Data Exchange (ETDEWEB)

Jammet, H.; Mechali, D.; Dousset, M. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1964-07-01

residus radioactifs produits par les installations nucleaires. L'evaluation du risque encouru par les populations et la fixation des limites admissibles pour les rejets ne peuvent resulter que d'une connaissance exacte du cheminement des radioelements rejetes, depuis leur source d'emission jusqu'a l'homme. L'incorporation des radioelements dans les chaines alimentaires constitue le premier risque a prendre en consideration. Les facteurs de passage doivent etre envisages, dans toutes les etapes de cette transmission, qu'elles interessent les milieux physiques ou les milieux proprement biologiques, du fait de leur continuite et de leur interdependance. Enfin, les donnees de caractere socio-economique et dietetique doivent etre recueillies pour conduire a une evaluation des risques et des niveaux admissibles reposant non sur des donnees theoriques mais sur des bases concretes et experimentales. Le risque d'accidents nucleaires dans l'industrie atomique, bien que de probabilite tres reduite, doit etre pris en consideration du fait de la gravite de leurs consequences. Les problemes sanitaires se posent d'une part dans le domaine de l'hygiene professionnelle, d'autre part dans celui de l'hygiene publique. Le premier domaine implique un risque double: d'irradiation et de contamination. Le domaine public n'est soumis essentiellement qu'au risque de contamination par les substances radioactives liberees accidentellement dans le milieu. Les etudes sanitaires a mener dans ce domaine comprennent, de ce fait, les recherches sur la therapeutique des irradiations ou des contaminations mais aussi celles relatives au transfert des radioelements depuis l'installation accidentee jusqu'a l'homme, principalement a travers les chaines alimentaires, dans leurs composantes physiques comme dans leurs composantes biologiques. De telles etudes sont a la base des decisions d'ordre sanitaire qu

Facility for the separation of krypton and recuperation of xenon

International Nuclear Information System (INIS)

Boell-Djoa, S.H.

1977-01-01

A facility is described by means of which the fission inert gases krypton 85 and xenon from spent fuel particles can be separated by fractionated freezing-out and subsequent distillation to such an extent that the xenon contains less than 1 ppb krypton 85. Then, in accordance with the stringent regulations, the krypton can be conveyed to definitive storage in special bottles, whereas the xenon can be released for industrial uses. (orig.) [de

Optimal sizes and siting of nuclear fuel reprocessing plants; Tailles et localisations optimales des usines de retraitement des combustibles nucleaires

Energy Technology Data Exchange (ETDEWEB)

Thiriet, L; Deledicq, A [Commissariat a l' Energie Atomique, Siege (France). Centre d' Etudes Nucleaires

1967-07-01

traite le probleme des usines de traitement de l'uranium naturel irradie associees a des centrales nucleaires a uranium naturel-graphite CO{sub 2}. La localisation et la production annuelle des reacteurs, les sites possibles d'usines et les fonctions de cout (transport et retraitement) sont supposes connus. La methode consiste a traiter d'abord le probleme des usines de traitement comme un probleme de programmation dynamique, des tranches croissantes de programmes (production totale des reacteurs) etant explorees sequentiellement. Lorsque les quantites d'uranium naturel irradie a retraiter sont fixees, la minimisation du cout de transport est alors effectuee, elle aussi comme un probleme de programmation dynamique. On explore le voisinage de l'optimum du cout de traitement pour trouver le minimum de la somme d'un cout de traitement sous-optimal et du cout de transport optimal correspondant. Le probleme de retraitement etant representable sur un graphe sequentiel, l'algorithme utilise pour calculer les sous-optima est 'l'algorithme a reflexion' que nous avons elabore. La methode s'interprete comme un mecanisme general de determination de l'optimum lorsque, a un probleme dynamique sequentiel (par exemple un programme d'equipement), se superpose un probleme complementaire (par exemple de transport). Elle permet en outre d'evaluer les pertes resultant du choix, pour des raisons autres qu'economiques, d'une politique non optimale. (auteur)

Nuclear developments at the international inter govern mental level (1961); Developpements nucleaires sur le plan international intergouvernemental (1961)

Energy Technology Data Exchange (ETDEWEB)

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

1961-07-01

The United Nations organisation and nuclear energy rose simultaneously, in 1945, to occupy an important place in the public eye. The spiritual succession of the League of Nations which had foundered during the war was taken up by the new organisation which sought to implant its political ideal in a more tangible reality, so that it might thereby be inspired by concrete and substantial objectives. This is one of the reasons for the existence of the dozen specialized agencies created by the family of the United Nations and dealing with Health, Culture, Agriculture, Finance, etc. Nuclear energy is one of these techniques. Becoming suddenly an important power factor and exploiting for itself the prestige of Science, it became the favorite domain for the growth of this new spirit, as much in its universal form in 1945 as in its more regional form which it was later to adopt. The achievements are numerous and of varying importance; they deserve te be studied carefully. (author) [French] L'organisation des Nations Unies et le nucleaire ont ete places simultanement, en 1945, au premier plan de la scene mondiale. La Societe des Nations ayant sombre pendant la guerre, son heritage spirituel fut recueilli par la nouvelle organisation qui chercha a enraciner son ideal politique dans une realite plus materielle, de facon a y puiser une nourriture concrete et substantielle. C'est une des raisons d'existence de la douzaine d'institutions specialisees gravitant dans la famille des Nations Unies et s'occupant de Sante, de Culture, d'Agriculture, de Finances, etc. Le nucleaire est l'une de ces techniques. Devenu soudainement un facteur primordial de puissance, Cristallisant a son benefice le prestige de la Science, c'etait un terrain de predilection pour le developpement du nouvel esprit, aussi bien sous la forme universelle de 1945, que sous les formes regionales qui ont vu le jour ensuite. Les travaux realises que nombreux, d'importance tres inegale. Ils meritent qu'on les examine

Nuclear developments at the international inter govern mental level (1961); Developpements nucleaires sur le plan international intergouvernemental (1961)

Energy Technology Data Exchange (ETDEWEB)

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

1961-07-01

The United Nations organisation and nuclear energy rose simultaneously, in 1945, to occupy an important place in the public eye. The spiritual succession of the League of Nations which had foundered during the war was taken up by the new organisation which sought to implant its political ideal in a more tangible reality, so that it might thereby be inspired by concrete and substantial objectives. This is one of the reasons for the existence of the dozen specialized agencies created by the family of the United Nations and dealing with Health, Culture, Agriculture, Finance, etc. Nuclear energy is one of these techniques. Becoming suddenly an important power factor and exploiting for itself the prestige of Science, it became the favorite domain for the growth of this new spirit, as much in its universal form in 1945 as in its more regional form which it was later to adopt. The achievements are numerous and of varying importance; they deserve te be studied carefully. (author) [French] L'organisation des Nations Unies et le nucleaire ont ete places simultanement, en 1945, au premier plan de la scene mondiale. La Societe des Nations ayant sombre pendant la guerre, son heritage spirituel fut recueilli par la nouvelle organisation qui chercha a enraciner son ideal politique dans une realite plus materielle, de facon a y puiser une nourriture concrete et substantielle. C'est une des raisons d'existence de la douzaine d'institutions specialisees gravitant dans la famille des Nations Unies et s'occupant de Sante, de Culture, d'Agriculture, de Finances, etc. Le nucleaire est l'une de ces techniques. Devenu soudainement un facteur primordial de puissance, Cristallisant a son benefice le prestige de la Science, c'etait un terrain de predilection pour le developpement du nouvel esprit, aussi bien sous la forme universelle de 1945, que sous les formes regionales qui ont vu le jour ensuite. Les travaux realises que nombreux, d

Life scientists in the nuclear domain

International Nuclear Information System (INIS)

Guetat, Philippe; Egal, Yves; Wolf, Gerard; Fleuriot, Sabine; Van Hecke, Walter; Coulon, Remi; Seilhean-Frossard, Estelle; Sevin, Helene; Schoulz, Daniel; Lebaron-Jacobs, Laurence; Menetrier, Florence; Crochon, Philippe; Buchholzer, Vincent; Chagvardieff, Pierre; Camus, Henri; Raynaud, Jacques; Biet, Elodie; Mathis, Paul

2011-01-01

This dossier is made of several small articles entitled: - 'Exploite intelligemment, le nucleaire n'est pas dangereux' (Exploited smartly, nuclear is not dangerous); - 'l'amont du cycle du combustible nucleaire' (the upstream part of the nuclear fuel cycle); - 'Le nucleaire, une energie recyclable' (Nuclear, a recyclable energy); - 'Centrale nucleaire et environnement - exemple de Cattenom' (Nuclear power station and the environment - the example of Cattenom); - 'Ingenieur environnement, un metier exigeant' (Engineer in environment, a demanding profession); - 'Rayonnements ionisants: a quels risques sommes-nous exposes?' (Ionizing radiations: to which risks are we exposed?); - 'Les anciennes mines d'uranium, un sujet toujours d'actualite' (Old uranium mines: a topic always of actuality); - 'Les dechets nucleaires, des dechets comme les autres?' (Nuclear wastes: wastes like others?); - 'Les Ingenieurs du Vivant dans le nucleaire' (Engineers in life sciences in the nuclear sector); - 'Tchernobyl: 25 ans apres, quel impact sur la sante?' (Chernobyl: 25 years after: which impact on health?); - 'Fukushima, catastrophe naturelle ou accident nucleaire?' (Fukushima, natural disaster or nuclear accident?); - 'Rehabiliter les sols contamines' (Restoring contaminated soils); - 'Nucleaire et risque de proliferation' (nuclear and risk of proliferation); - 'Les rayonnements dans la lutte contre le cancer' (Radiations in the struggle against cancer); - 'L'energie nucleaire est-elle essentielle a notre bouquet energetique?' (Is nuclear energy essential to our energy mix?). The articles of this dossier outline that nuclear energy can be exploited without any danger if it is done intelligently, describes the upstream part of the nuclear fuel cycle, outlines that most of the nuclear fuel can be recycled, presents the activities of survey and control of the environment around a French nuclear power station, outlines the high commitment required for and engineer in environment working

Ionization and scintillation of nuclear recoils in gaseous xenon

Energy Technology Data Exchange (ETDEWEB)

Renner, J., E-mail: jrenner@lbl.gov [Lawrence Berkeley National Laboratory (LBNL), 1 Cyclotron Road, Berkeley, CA 94720 (United States); Department of Physics, University of California, Berkeley, CA 94720 (United States); Gehman, V.M.; Goldschmidt, A.; Matis, H.S.; Miller, T.; Nakajima, Y.; Nygren, D.; Oliveira, C.A.B.; Shuman, D. [Lawrence Berkeley National Laboratory (LBNL), 1 Cyclotron Road, Berkeley, CA 94720 (United States); Álvarez, V. [Instituto de Física Corpuscular (IFIC), CSIC & Universitat de València, Calle Catedrático José Beltrán, 2, 46980 Paterna, Valencia (Spain); Borges, F.I.G. [Departamento de Fisica, Universidade de Coimbra, Rua Larga, 3004-516 Coimbra (Portugal); Cárcel, S. [Instituto de Física Corpuscular (IFIC), CSIC & Universitat de València, Calle Catedrático José Beltrán, 2, 46980 Paterna, Valencia (Spain); Castel, J.; Cebrián, S. [Laboratorio de Física Nuclear y Astropartículas, Universidad de Zaragoza, Calle Pedro Cerbuna 12, 50009 Zaragoza (Spain); Cervera, A. [Instituto de Física Corpuscular (IFIC), CSIC & Universitat de València, Calle Catedrático José Beltrán, 2, 46980 Paterna, Valencia (Spain); Conde, C.A.N. [Departamento de Fisica, Universidade de Coimbra, Rua Larga, 3004-516 Coimbra (Portugal); and others

2015-09-01

Ionization and scintillation produced by nuclear recoils in gaseous xenon at approximately 14 bar have been simultaneously observed in an electroluminescent time projection chamber. Neutrons from radioisotope α-Be neutron sources were used to induce xenon nuclear recoils, and the observed recoil spectra were compared to a detailed Monte Carlo employing estimated ionization and scintillation yields for nuclear recoils. The ability to discriminate between electronic and nuclear recoils using the ratio of ionization to primary scintillation is demonstrated. These results encourage further investigation on the use of xenon in the gas phase as a detector medium in dark matter direct detection experiments.

Quantitative cerebral blood flow calculation method using xenon CT. Introduction of a factor reflecting diffusing capacity of the lung for xenon

International Nuclear Information System (INIS)

Sase, Shigeru; Honda, Mitsuru; Noguchi, Yoshitaka

2007-01-01

In calculating cerebral blood flow (CBF) using the Fick principle, time-course information on arterial tracer concentration is indispensable and exerts considerable influence on the accuracy of CBF. In xenon-enhanced CT (Xe-CT), the time-course change rate for end-tidal xenon concentration (Ke), which can be measured, and that for arterial xenon concentration (Ka) have been assumed to be equal. However, it has been pointed out that there are large differences between Ke and Ka in many cases. We have introduced a single factor (γ) which correlates Ke with Ka in the equation Ka=γ x (1-e -Ke/γ ). This factor, γ, reflects the diffusing capacity of the lung for xenon; larger γ values correspond to larger diffusing capacities and Ka is equal to Ke when γ is infinity. Kety's equation contains two parameters: CBF and xenon solubility coefficient We added a third parameter, γ, to Kety's equation, and developed an efficient method to obtain the γ value for each Xe-CT study. Applying this method to ten normal subjects (35.4±16.3 years, mean±standard deviation (SD)), we obtained γ value of 1.01±0.17 and the average CBF value of 38.8±7.5 mL/100 g/min in basal ganglia. The wash-in period could be shortened to two minutes using this method. Xe-CT with this factor (γ) as a parameter enhances its clinical availability as well as the accuracy of CBF. (author)

Xenon as an adjunct in computed tomography

International Nuclear Information System (INIS)

Kendall, B.E.; Radue, E.W.; Zilkha, E.; Loh, L.

1979-01-01

Nonradioactive xenon was used for enhancement in computed tomography in a series of 18 patients requiring general anesthesia. The method and results are described. The properties of xenon are radically different from those of intravenous iodides, and the enhancement patterns demonstrate different aspects of both normal and abnormal tissues. In our limited experience, it has been of value in those isodense and low attenuation lesions that have not enhanced after intravenous Conray. (orig.) 891 MG/orig. 892 MB [de

Performance test of SAUNA xenon mobile sampling system

International Nuclear Information System (INIS)

Hu Dan; Yang Bin; Yang Weigeng; Jia Huaimao; Wang Shilian; Li Qi; Zhao Yungang; Fan Yuanqing; Chen Zhanying; Chang Yinzhong; Liu Shujiang; Zhang Xinjun; Wang Jun

2011-01-01

In this article, the structure and basic functions of SAUNA noble gas xenon mobile sampling system are introduced. The sampling capability of this system is about 2.2 mL per day, as a result from a 684-h operation. The system can be transported to designated locations conveniently to collect xenon sample for routine or emergency environment monitoring. (authors)

Design and commissioning of ReStoX for XENON1T

Energy Technology Data Exchange (ETDEWEB)

Scheibelhut, Melanie [Institut fuer Physik, Johannes Gutenberg Universitaet Mainz (Germany)

2015-07-01

The XENON1T experiment, currently under construction at the Gran Sasso underground laboratory LNGS, uses the concept of a xenon dual-phase (liquid/gas) time projection chamber to search for Dark Matter particles. This requires cooling to about 175 K and liquefaction of the noble gas. The ReStoX (Recovery and Storage of Xenon) is a novel device to store and recover up to 7 tons of xenon - either in liquid phase at cryogenic temperatures and 1-2 bar of pressure, or in gaseous form at room temperature at about 70 bar of pressure. The ReStoX system consists of a double insulated stainless steel sphere with liquid nitrogen cooling loops distributed across the inner sphere. A condenser on the inside, also operated with liquid nitrogen, provides a cooling power of 3 kW. ReStoX is designed to provide an effective means for various operating modes: to fill the TPC fast, to recover xenon from the TPC under normal and emergency conditions, to store xenon safely in liquid or gaseous form, or to remain in cold standby nearly empty as a safety device. Here we present the design and first commissioning results.

Single Ion Trapping for the Enriched Xenon Observatory

Energy Technology Data Exchange (ETDEWEB)

Waldman, Samuel J.; /Stanford U., Phys. Dept. /SLAC

2006-03-28

In the last decade, a variety of neutrino oscillation experiments have established that there is a mass difference between neutrino flavors, without determining the absolute neutrino mass scale. The Enriched Xenon Observatory for neutrinoless double beta decay (EXO) will search for the rare decays of xenon to determine the absolute value of the neutrino mass. The experiment uses a novel technique to minimize backgrounds, identifying the decay daughter product in real time using single ion spectroscopy. Here, we describe single ion trapping and spectroscopy compatible with the EXO detector. We extend the technique of single ion trapping in ultrahigh vacuum to trapping in xenon gas. With this technique, EXO will achieve a neutrino mass sensitivity of {approx_equal} .010 eV.

Health physics problems in the context of the development of industrial uses of nuclear energy; Les problemes de radioprotection devant le developpement de l'utilisation industrielle de l'energie nucleaire

Energy Technology Data Exchange (ETDEWEB)

Duhamel, F.; Menoux, A. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

fate of radioactive ions in the hydrosphere may be determined. - experiments and studies linked with the possibilities for disposal a underground storage of wastes. All these studies cover a complementary field, that of radioprotection, which forms the necessary link between nuclear safety proper, which concerns the actual operation of nuclear installations and medical supervision which directly concerns the health of the individual and the population. At the same time each one of the Health Physics disciplines possesses an independence which increases their efficiency on the safety level. (authors) [French] Le developpement de l'utilisation industrielle de l'energie nucleaire a mis l'accent sur la necessite de promouvoir une doctrine rationnelle et coherente en matiere de securite des installations atomiques et plus particulierement en matiere de securite des sites nucleaires. Le but principal de la securite est de diminuer, voire d'annuler les risques d'irradiation ou de contamination des travailleurs et de la population, consecutifs au fonctionnement normal ou accidentel des installations. La securite est obtenue par la mise en oeuvre d'un ensemble complexe de moyens. Parmi ces moyens les auteurs considerent essentiellement ceux qui presentent une certaine independance a l'egard du type d'installation: moyens d'alerte et de mesure et leur mise en oeuvre - preparation psychologique et technique des individus - evaluation de la capacite d'un site a absorber les rejets radioactifs sans dommage pour la population. Il est clair en effet que les consequences d'un accident sont diminuees par l'augmentation de la valeur des moyens de surveillance, de mesure et d'alerte, l'elevation du niveau technique et l'entrainement du personnel, l'education de la population. Ceci est particulierement vrai aupres d'une installation nucleaire ou l'etude des dangers presente un caractere abstrait et

The use of polarized deuterons beams and the determination of the optical model parameters; Utilisation de faisceaux de deutons polarises et determination des parametres du modele optique

Energy Technology Data Exchange (ETDEWEB)

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

1964-06-15

entraine des relations entre les parametres adoptes. Les limitations de ces parametres sont etudiees specialement dans le cas d'un faisceau de particules de spin 1 ayant un plan de symetrie. Les reactions nucleaires a deux corps sont decrites dans le formalisme de l'helicite. A l'aide des coefficients de polarisation adoptes, on etudie la polarisation dans l'etat final avec etat initial polarise. Un potentiel optique pour deutons pout comprendre une partie scalaire, un couplage L.S et des potentiels tensoriels formes avec la distance du deuton au noyau, son moment angulaire ou son impulsion relative. Des calculs ont ete faits avec les deux premieres sortes de potentiels tensoriels. Plusieurs auteurs ont calcule un potentiel pour deutons a partir du modele optique nucleon oyau. Ces calculs sont repris en considerant l'onde S et l'onde D du deuton. Les differentes parties du potentiel ont ete calculees avec plusieurs fonctions d'onde intrinseque. L'utilisation de potentiels non uniquement scalaires permet d'obtenir de bons accords pour la section efficace avec des rayons nucleaires plus eleves que ceux necessaires avec un potentiel purement central. Les mesures experimentales de polarisation faites a Saclay pour la diffusion elastique de deutons sur le calcium sont en desaccord avec l'existence d'un potentiel tensoriel important ; elles peuvent etre reproduites en utilisant un couplage L.S. independant du potentiel central, mais avec des rayons tres faibles. (auteur)

Reduction des effectifs ou licenciements

CERN Multimedia

Maiani, Luciano

2002-01-01

"Vous faites un amalgame entre la reduction en cours des effectifs du CERN (organisation europeenne pour la recherche nucleaire) et les economies que le laboratoire doit realiser dans les cinq ans a venir pour financer le projet de grand collisionneur de hadrons (Le Monde du 4 septembre)" (1/2 page).

Collision-induced light scattering in a thin xenon layer between graphite slabs - MD study.

Science.gov (United States)

Dawid, A; Górny, K; Wojcieszyk, D; Dendzik, Z; Gburski, Z

2014-08-14

The collision-induced light scattering many-body correlation functions and their spectra in thin xenon layer located between two parallel graphite slabs have been investigated by molecular dynamics computer simulations. The results have been obtained at three different distances (densities) between graphite slabs. Our simulations show the increased intensity of the interaction-induced light scattering spectra at low frequencies for xenon atoms in confined space, in comparison to the bulk xenon sample. Moreover, we show substantial dependence of the interaction-induced light scattering correlation functions of xenon on the distances between graphite slabs. The dynamics of xenon atoms in a confined space was also investigated by calculating the mean square displacement functions and related diffusion coefficients. The structural property of confined xenon layer was studied by calculating the density profile, perpendicular to the graphite slabs. Building of a fluid phase of xenon in the innermost part of the slot was observed. The nonlinear dependence of xenon diffusion coefficient on the separation distance between graphite slabs has been found. Copyright © 2014. Published by Elsevier B.V.

Cryogenic separation of krypton and xenon from dissolver off-gas

Energy Technology Data Exchange (ETDEWEB)

Bohnenstingl, J.; Heidendael, M.; Laser, M.; Mastera, S.; Merz, E.

1976-03-15

Although the release of fission product noble gas Kr-85 has not posed a health problem to date, a process is being developed for the removal and storage of fission product noble gases from dissolution process stream of fuel reprocessing. The separation process described for noble gas in air being proved in semi-technical scale includes cryogenic distillation and consists of the following steps: (1) removal of ^{129 +131}iodine on silver-coated silica gel; (2) deposition of particulate materials by HEPA-filters; (3) elimination of O₂ and NO_x by catalytic conversion with H₂/ to N₂ and H₂O; (4) drying of the gas stream with molecular sieve; (5) deposition of xenon in solid form at about 80 K, while the remaining gas components are liquified; (6) enrichment of Kr by low temperature distillation of liquid-gas mixture; (7) withdrawal of the highly enriched Kr-fraction at the bottom of the still to be bottled in pressurized steel cylinders for final disposal; and (8) purification of Kr-85 contaminated Xe for further industrial reuse by batch distillation.

Josephinite. A terrestrial alloy with radiogenic xenon-129 and the noble gas imprint of iron meteorites

Energy Technology Data Exchange (ETDEWEB)

Downing, R G; Hennecke, E W; Manuel, O K [Missouri Univ., Rolla (USA). Dept. of Chemistry

1977-12-01

Analyses of noble gases released by stepwise heating of Josephinite reveal two radiogenic components, radiogenic /sup 129/Xe asymptotically equals 1 x 10/sup -12/ ccSTP/g and radiogenic /sup 40/Ar asymptotically equals 1 x 10/sup -6/ cc STP/g, and the following components of trapped noble gases: He with /sup 3/He//sup 4/He asymptotically equals 4 x 10/sup -5/, Ne with /sup 20/Ne//sup 22/Ne=10.5, Ar with /sup 40/Ar//sup 36/Ar=3 x 10/sup 2/, and Kr and Xe with isotopic compositions similar to those observed in iron meteorites. The excess of /sup 40/Ar and literature values of K in bulk Josephinite yield and apparent K-Ar age of asymptotically equals 4.6 x 10/sup 9/ years.

Spatial xenon oscillation control with expert systems

International Nuclear Information System (INIS)

Alten, S.; Danofsky, R.A.

1993-01-01

Spatial power oscillations were attributed to the xenon transients in a reactor core in 1958 by Randall and St. John. These transients are usually initiated by a local reactivity insertion and lead to divergent axial flux oscillations in the core at constant power. Several heuristic manual control strategies and automatic control methods were developed to damp the xenon oscillations at constant power operations. However, after the load-follow operation of the reactors became a necessity of life, a need for better control strategies arose. Even though various advanced control strategies were applied to solve the xenon oscillation control problem for the load-follow operation, the complexity of the system created difficulties in modeling. The strong nonlinearity of the problem requires highly sophisticated analytical approaches that are quite inept for numerical solutions. On the other hand, the complexity of a system and heuristic nature of the solutions are the basic reasons for using artificial intelligence techniques such as expert systems

Spectral content of seismic movements produced by underground nuclear explosions; Contenu spectral des mouvements seismiques dus aux explosions nucleaires souterraines

Energy Technology Data Exchange (ETDEWEB)

Albaret, A; Duclaux, F [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

1969-07-01

After a summary of available data, both theoretical and experimental, concerning the spectral content of seismic movements, a description is given of the experiments carried out during the French nuclear explosions in the Sahara, and of the results obtained on the volume waves. A comparison is then made with certain American results. A new method is described for studying the amplitude spectra; it has made it possible to show that the amount of low frequencies in the spectrum increases with the power of the explosion, and decreases with the distance to the zero point and with the filtering effect of the weathered zone. A calculation is then made of the low cut-off ground filter, this giving a better representation of the initial seismic phenomenon. (authors) [French] Apres avoir resume les connaissances disponibles, aussi bien theoriques qu'experimentales, sur le contenu spectral des mouvements seismiques, on decrit les experiences effectuees a l'occasion des explosions nucleaires francaises du Sahara et les resultats obtenus sur les ondes de volume. Puis on les compare avec certains resultats americains. On decrit une nouvelle methode d'etude des spectres d'amplitudes qui montre que le spectre est d'autant plus riche en basses frequences que la puissance de l'explosion est grande, que la distance au point zero est faible et qu'il est moins filtre par la zone alteree superficielle. Puis on calcule le filtre terrain coupe-bas qui permet de donner une representation plus fidele du phenomene seismique initial. (auteurs)

Exposure mode study to xenon-133 in a reactor building

International Nuclear Information System (INIS)

Perier, Aurelien

2014-01-01

The work described in this thesis focuses on the external and internal dose assessment to xenon-133. During the nuclear reactor operation, fission products and radioactive inert gases, as 133 Xe, are generated and might be responsible for the exposure of workers in case of clad defect. Particle Monte Carlo transport code is adapted in radioprotection to quantify dosimetric quantities. The study of exposure to xenon-133 is conducted by using Monte-Carlo simulations based on GEANT4, an anthropomorphic phantom, a realistic geometry of the reactor building, and compartmental models. The external exposure inside a reactor building is conducted with a realistic and conservative exposure scenario. The effective dose rate and the eye lens equivalent dose rate are determined by Monte-Carlo simulations. Due to the particular emission spectrum of xenon-133, the equivalent dose rate to the lens of eyes is discussed in the light of expected new eye dose limits. The internal exposure occurs while xenon-133 is inhaled. The lungs are firstly exposed by inhalation, and their equivalent dose rate is obtained by Monte-Carlo simulations. A biokinetic model is used to evaluate the internal exposure to xenon-133. This thesis gives us a better understanding to the dosimetric quantities related to external and internal exposure to xenon-133. Moreover the impacts of the dosimetric changes are studied on the current and future dosimetric limits. The dosimetric quantities are lower than the current and future dosimetric limits. (author)

Gravity assisted recovery of liquid xenon at large mass flow rates

Science.gov (United States)

Virone, L.; Acounis, S.; Beaupère, N.; Beney, J.-L.; Bert, J.; Bouvier, S.; Briend, P.; Butterworth, J.; Carlier, T.; Chérel, M.; Crespi, P.; Cussonneau, J.-P.; Diglio, S.; Manzano, L. Gallego; Giovagnoli, D.; Gossiaux, P.-B.; Kraeber-Bodéré, F.; Ray, P. Le; Lefèvre, F.; Marty, P.; Masbou, J.; Morteau, E.; Picard, G.; Roy, D.; Staempflin, M.; Stutzmann, J.-S.; Visvikis, D.; Xing, Y.; Zhu, Y.; Thers, D.

2018-06-01

We report on a liquid xenon gravity assisted recovery method for nuclear medical imaging applications. The experimental setup consists of an elevated detector enclosed in a cryostat connected to a storage tank called ReStoX. Both elements are part of XEMIS2 (XEnon Medical Imaging System): an innovative medical imaging facility for pre-clinical research that uses pure liquid xenon as detection medium. Tests based on liquid xenon transfer from the detector to ReStoX have been successfully performed showing that an unprecedented mass flow rate close to 1 ton per hour can be reached. This promising achievement as well as future areas of improvement will be discussed in this paper.

Modeling Xenon Purification Systems in a Laser Inertial Fusion Engine

Science.gov (United States)

Hopkins, Ann; Gentile, Charles

2011-10-01

A Laser Inertial Fusion Engine (LIFE) is a proposed method to employ fusion energy to produce electricity for consumers. However, before it can be built and used as such, each aspect of a LIFE power plant must first be meticulously planned. We are in the process of developing and perfecting models for an exhaust processing and fuel recovery system. Such a system is especially essential because it must be able to recapture and purify expensive materials involved in the reaction so they may be reused. One such material is xenon, which is to be used as an intervention gas in the target chamber. Using Aspen HYSYS, we have modeled several subsystems for exhaust processing, including a subsystem for xenon recovery and purification. After removing hydrogen isotopes using lithium bubblers, we propose to use cryogenic distillation to purify the xenon from remaining contaminants. Aspen HYSYS allows us to analyze predicted flow rates, temperatures, pressures, and compositions within almost all areas of the xenon purification system. Through use of Aspen models, we hope to establish that we can use xenon in LIFE efficiently and in a practical manner.

Evolution of nuclear chemical industry in France; Evolution de l'industrie chimique nucleaire en France

Energy Technology Data Exchange (ETDEWEB)

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

1959-07-01

'impulsion du CEA, mais aussi de maitres d'oeuvres tels qu'Electricite de France et la Marine Marchande, l'effort nucleaire fran is atteint pour les annees 1957-1961, environ 600 milliards de francs: plus de la moitie de cette somme sera depensee par l'industrie chimique en recherches, installations pilotes, constructions d'usines et livraisons. Faire bien, vite et rentable sont les buts recherches. Ces objectifs sont atteints grace a une collaboration intime des grands services de l'etat et de l'industrie privee. Ce gros effort s'exerce principalement dans les voies suivantes: - Un traitement chimique pousse de tonnages croissants des minerais de l'Union fran ise, visant a produire un uranium pur, abondant et bon marche. - Une preparation soigneuse de combustibles nucleaires economiques et parfaitement adaptes aux divers types de reacteurs en fonctionnement ou en construction. - Un retraitement des combustibles irradies pour en extraire le plutonium de facon complete ainsi que l'uranium et certains produits de fission. - Une fabrication industrielle des materiaux nucleairement purs ou resistants a la corrosion exiges par la technologie des reacteurs producteurs d'energie et de recherches. - La fourniture aux multiples utilisateurs etrangers et fran is d'isotopes et de traceurs radioactifs reclames par la medecine, l'industrie et l'agriculture en nombre toujours croissant. - Un traitement chimique meticuleux des effluents gazeux ou liquides dans des stations au controle rigoureux afin de rendre les reacteurs et leurs annexes parfaitement surs d'emploi. Cet expose aura montre l'ampleur de l'effort deploye par une industrie chimique nucleaire jeune, dynamique et en plein essor. Ayant assure ses techniques, realise de nombreuses installations, elle est largement en etat de faire face au programme atomique fran is. En outre, elle est capable et desireuse d'etre associee aux developpements de l'industrie atomique etrangere notamment dans te cadre de l'Euratom et d

Contribution to the study of {beta} disintegration and of nuclear structure using experiments on certain {beta}-{gamma} cascades: 198{sub Au}, 86{sub Rb}, 170{sub Tm}; Contribution a l'etude de la desintegration beta et a l'etude de la structure nucleaire a l'aide d'experiences sur certaines cascades beta-gamma: 198{sub Au}, 86{sub Rb}, 170{sub Tm}

Energy Technology Data Exchange (ETDEWEB)

Lachkar, J. [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes; Paris-11 Univ., fabulte des Sciences 91 - Orsay (France)

1969-07-01

{beta}{gamma} directional angular correlations and shapes of inner beta spectra leading to the first excited level of the final nucleus enable one to determine the nuclear matrix elements typical of the {beta} transition. In the three observed first forbidden cases: {sup 170}Tm, {sup 86}Rb, {sup 198}Au, these matrix elements do not confirm the independent shell model theory. Other hypotheses are then suggested and discussed. (author) [French] Les experiences de correlation angulaire {beta}{gamma} et l'etude du spectre {beta} conduisant au premier niveau excite du noyau final permettent de determiner les elements de matrices nucleaires caracteristiques de cette transition. Dans les trois cas etudies (transitions une fois interdites): {sup 170}Tm, {sup 86}Rb, {sup 198}Au, ces elements de matrices ne peuvent etre retrouves a l'aide du modele en couches et a particules independantes. D'autres hypotheses sont alors emises et discutees. (auteur)

Xenon-Water Interaction in Bacterial Suspensions as Studied by NMR

DEFF Research Database (Denmark)

Rodin, V.; Ponomarev, Alexander; Gerasimov, Maxim

2017-01-01

suspensions of Escherichia coli in the presence of xenon using nuclear magnetic resonance (NMR). The work studied how the spin-lattice relaxation times of water protons in suspension change under xenon conditions. Xenon is able to form clathrate hydrates with water molecules at a temperature above the melting...... point of ice. The work studied NMR relaxation times which reflect the rotation freedom of water molecules in suspension. Lower relaxation times indicate reduced rotational freedom of water. Single exponential behavior of spin-lattice relaxation of protons in the suspensions of microorganisms has been...

Actinide and Xenon reactivity effects in ATW high flux systems

International Nuclear Information System (INIS)

Woosley, M.; Olson, K.; Henderson, D.L.

1995-01-01

In this paper, initial system reactivity response to flux changes caused by the actinides and xenon are investigated separately for a high flux ATW system. The maximum change in reactivity after a flux change due to the effect of the changing quantities of actinides is generally at least two orders of magnitude smaller than either the positive or negative reactivity effect associated with xenon after a shutdown or start-up. In any transient flux event, the reactivity response of the system to xenon will generally occlude the response due to the actinides

Actinide and xenon reactivity effects in ATW high flux systems

International Nuclear Information System (INIS)

Woosley, M.; Olson, K.; Henderson, D. L.; Sailor, W. C.

1995-01-01

In this paper, initial system reactivity response to flux changes caused by the actinides and xenon are investigated separately for a high flux ATW system. The maximum change in reactivity after a flux change due to the effect of the changing quantities of actinides is generally at least two orders of magnitude smaller than either the positive or negative reactivity effect associated with xenon after a shutdown or start-up. In any transient flux event, the reactivity response of the system to xenon will generally occlude the response due to the actinides

Actinide and Xenon reactivity effects in ATW high flux systems

Energy Technology Data Exchange (ETDEWEB)

Woosley, M. [Univ. of Virginia, Charlottesville, VA (United States); Olson, K.; Henderson, D.L. [Univ. of Wisconsin, Madison, WI (United States)] [and others

1995-10-01

In this paper, initial system reactivity response to flux changes caused by the actinides and xenon are investigated separately for a high flux ATW system. The maximum change in reactivity after a flux change due to the effect of the changing quantities of actinides is generally at least two orders of magnitude smaller than either the positive or negative reactivity effect associated with xenon after a shutdown or start-up. In any transient flux event, the reactivity response of the system to xenon will generally occlude the response due to the actinides.

Memory Effects Study of Measuring Radioactive Xenon Isotopes With β-γ Coincidence Method

International Nuclear Information System (INIS)

Jia Huaimao; Wang Shilian; Wang Jun; Li Qi; Zhao Yungang; Fan Yuanqing; Zhang Xinjun

2010-01-01

The β-γ coincidence technique is a kind of the key important method to detect radioactive xenon isotopes for the Comprehensive Nuclear-Test-Ban Treaty (CTBT). This paper describes noble gases memory effects of β-γ coincidence detector. Xenon memory effects were measured and its influence on detector's minimum detectable activity (MDA) was evaluated. The methods of reducing xenon memory effects were studied. In conclusion, aluminium coated plastic scintillator and YAP scintillator can remarkably decrease xenon memory effects. (authors)

A dual-phase xenon TPC for scintillation and ionisation yield measurements in liquid xenon

Science.gov (United States)

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.

Neutron detection in an atomic reactor core using semi-conductors; Detection des neutrons par semi-conducteur dans un coeur de reacteur atomique

Energy Technology Data Exchange (ETDEWEB)

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

1968-07-01

In this paper, the first part describes the principle of nuclear particle detection by means of semiconductor diodes and the general application of these. The second part describes fabrication of the device used to estimate thermic neutron fluxes in core of a swimming pool type reactor. The useful volume (2.9 mm thickness) is in the light water moderator, between combustible elements plates. The results, principally obtained in the core of Siloette reactor at the 'Centre d'Etudes Nucleaires de Grenoble' at low power, are mentioned in the third part. Flux maps have been set and comparison between converter's products: Bore 10, Lithium 6, Uranium 235 is made. (author) [French] Dans ce rapport, une premiere partie porte sur la description du principe de detection des particules nucleaires par diodes a semi-conducteur et sur l'application generale de celles-ci. Une deuxieme partie s'attache a decrire la fabrication du materiel utilise pour evaluer les flux de neutrons thermiques dans un coeur de reacteur type pile piscine. L'espace de mesure (2,9 mm d'epaisseur) se situe entre les plaques des elements combustibles, dans le moderateur eau legere. Les resultats, obtenus principalement dans le coeur du reacteur Siloette du Centre d'Etudes Nucleaires de Grenoble aux basses puissances de fonctionnement, sont rapportes dans la troisieme partie. Des cartes de flux ont ete dressees et une comparaison est faite entre les produits 'convertisseurs' suivants: Bore 10, Lithium 6, Uranium 235. (auteur)

Dynamic adsorption properties of xenon on activated carbons and their structure characterization

International Nuclear Information System (INIS)

Liu Suiqing; Liu Jing; Qian Yuan; Zeng Youshi; Du Lin; Pi Li; Liu Wei

2013-01-01

Background: In recent years, adsorption of radioactive xenon by activated carbon has been increasingly applied to the treatment of off-gas in nuclear power project. Though pore structure of activated carbon has a great impact on its dynamic adsorption coefficients for xenon, the concerned research is rare. Purpose: It is very necessary to figure out the relationship between the pore structure and the dynamic adsorption coefficients for the purpose of the selection and development of activated carbon. Methods: In this study, the dynamic adsorption coefficients of xenon on four kinds of activated carbons were measured on a dynamic adsorption platform under the condition of 25℃, OMPa (gauge pressure). And these four kinds of activated carbons were characterized by nitrogen adsorption and SEM. Results: The results show that the activated carbon of JH12-16 with the specific surface area of 991.9 m 2 ·g -1 has the largest xenon dynamic adsorption coefficient among these activated carbons. Conclusions: The dynamic adsorption coefficient of xenon on activated carbon doesn't increase with the specific surface area or the pore volume. The mesopore and macropore only play the role of passageway for xenon adsorption. The most suitable pore for xenon adsorption is the pore with the pore size ranged from 0.55 to 0.6 nm. (authors)

Ionization and scintillation response of high-pressure xenon gas to alpha particles

International Nuclear Information System (INIS)

Álvarez, V; Cárcel, S; Cervera, A; Díaz, J; Ferrario, P; Gil, A; Gómez-Cadenas, J J; Borges, F I G; Conde, C A N; Fernandes, L M P; Freitas, E D C; Cebrián, S; Dafni, T; Gómez, H; Egorov, M; Gehman, V M; Goldschmidt, A; Esteve, R; Evtoukhovitch, P; Ferreira, A L

2013-01-01

High-pressure xenon gas is an attractive detection medium for a variety of applications in fundamental and applied physics. In this paper we study the ionization and scintillation detection properties of xenon gas at 10 bar pressure. For this purpose, we use a source of alpha particles in the NEXT-DEMO time projection chamber, the large scale prototype of the NEXT-100 neutrinoless double beta decay experiment, in three different drift electric field configurations. We measure the ionization electron drift velocity and longitudinal diffusion, and compare our results to expectations based on available electron scattering cross sections on pure xenon. In addition, two types of measurements addressing the connection between the ionization and scintillation yields are performed. On the one hand we observe, for the first time in xenon gas, large event-by-event correlated fluctuations between the ionization and scintillation signals, similar to that already observed in liquid xenon. On the other hand, we study the field dependence of the average scintillation and ionization yields. Both types of measurements may shed light on the mechanism of electron-ion recombination in xenon gas for highly-ionizing particles. Finally, by comparing the response of alpha particles and electrons in NEXT-DEMO, we find no evidence for quenching of the primary scintillation light produced by alpha particles in the xenon gas.

Iodine-129 in the environment

International Nuclear Information System (INIS)

Tikhomirov, F.A.; Moiseev, I.T.

1987-01-01

The quantitative ratio of aerial and soil entries of 129 I into plants, parameters of its migration in the system of atmosphere-soil-plants-river water, dynamics of transformation and biological availability of 129 I in soil for plants were studied on the basis of field observations and experiments using the radioactive tracers. The doses of human thyroid gland irradiation by 129 I under atmospheric and soil pathways of its transport into diet are estimated. 129 I content in soil due to its systematic, for 50 years, releases into atmosphere is shown to be negligible, agricultural production contamination by 129 I resulting mainly from its fallout onto overground phytomass. The period, needed to achieve 129 I concentration equilibrium in the atmosphere-soil system under constant average 129 I content in the air, varies depending on the soil type from several hundred years (for podzolic soils) up to several thousand years (for chernozem). The 129 I half-accumulation period is equal to 150 years for soddy-podzolic soil and to 700 years for chernozem. In case of 129 I fallout lasting for 100 years the annual increase of its content in overground phytomass due to the transport from soil will account for 0,3% of its atmospheric entry way for soddy-podzolic soil and for 0,1% for chernozem, respectively. For a number of sierozem, yellow soil and calcareous chernozem types this addition is higher (up to 1%). Under constant iodine-129 concentration in air (1 Bq/m3) the absorbed dose for one-year child's thyroid gland in continental area is approximately equal to 2 (Gy/y)/(Bq/m3). The absorbed dose from globally dissipated 129 I under 99% efficiency of gas purification will not exceed 2·10 -7 Gy/y. The input of globally dissipated 129 I, originating from deep underground disposal of nuclear wastes can account for not more than 10 -9 Gy/y. In total, 129 I releases for the coming century is not going to produce limitations for nuclear energetics development. (author)

Experimental studies of a zeeman-tuned xenon laser differential absorption apparatus.

Science.gov (United States)

Linford, G J

1973-06-01

A Zeeman-tuned cw xenon laser differential absorption device is described. The xenon laser was tuned by axial magnetic fields up to 5500 G generated by an unusually large water-cooled dc solenoid. Xenon laser lines at 3.37 micro, 3.51 micro, and 3.99 micro were tuned over ranges of 6 A, 6 A, and 11 A, respectively. To date, this apparatus has been used principally to study the details of formaldehyde absorption lines lying near the 3 .508-micro xenon laser transition. These experiments revealed that the observed absorption spectrum of formaldehyde exhibits a sufficiently unique spectral structure that the present technique may readily be used to measure relative concentrations of formaldehyde in samples of polluted air.

On the spin-dependent sensitivity of XENON100

Energy Technology Data Exchange (ETDEWEB)

Garny, Mathias [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Ibarra, Alejandro; Pato, Miguel; Vogl, Stefan [Technische Univ. Muenchen, Garching (Germany). Physik-Department

2012-11-15

The latest XENON100 data severely constrains dark matter elastic scattering off nuclei, leading to impressive upper limits on the spin-independent cross-section. The main goal of this paper is to stress that the same data set has also an excellent spin-dependent sensitivity, which is of utmost importance in probing dark matter models. We show in particular that the constraints set by XENON100 on the spin-dependent neutron cross-section are by far the best at present, whereas the corresponding spin-dependent proton limits lag behind other direct detection results. The effect of nuclear uncertainties on the structure functions of xenon isotopes is analysed in detail and found to lessen the robustness of the constraints, especially for spin-dependent proton couplings. Notwith-standing, the spin-dependent neutron prospects for XENON1T and DARWIN are very encouraging. We apply our constraints to well-motivated dark matter models and demonstrate that in both mass-degenerate scenarios and the minimal supersymmetric standard model the spin-dependent neutron limits can actually override the spin-independent limits. This opens the possibility of probing additional unexplored regions of the dark matter parameter space with the next generation of ton-scale direct detection experiments.

On the spin-dependent sensitivity of XENON100

International Nuclear Information System (INIS)

Garny, Mathias; Ibarra, Alejandro; Pato, Miguel; Vogl, Stefan

2012-11-01

The latest XENON100 data severely constrains dark matter elastic scattering off nuclei, leading to impressive upper limits on the spin-independent cross-section. The main goal of this paper is to stress that the same data set has also an excellent spin-dependent sensitivity, which is of utmost importance in probing dark matter models. We show in particular that the constraints set by XENON100 on the spin-dependent neutron cross-section are by far the best at present, whereas the corresponding spin-dependent proton limits lag behind other direct detection results. The effect of nuclear uncertainties on the structure functions of xenon isotopes is analysed in detail and found to lessen the robustness of the constraints, especially for spin-dependent proton couplings. Notwith-standing, the spin-dependent neutron prospects for XENON1T and DARWIN are very encouraging. We apply our constraints to well-motivated dark matter models and demonstrate that in both mass-degenerate scenarios and the minimal supersymmetric standard model the spin-dependent neutron limits can actually override the spin-independent limits. This opens the possibility of probing additional unexplored regions of the dark matter parameter space with the next generation of ton-scale direct detection experiments.

Damage caused to houses and equipment by underground nuclear explosions; Degats dus aux explosions nucleaires souterraines sur les habitations et les equipements

Energy Technology Data Exchange (ETDEWEB)

Delort, F; Guerrini, C [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

1969-07-01

A description is given of the damaged caused to various structures, buildings, houses, mechanical equipment and electrical equipment by underground nuclear explosions in granite. For each type of equipment or building are given the limiting distances for a given degree of damage. These distances have been related to a parameter characterizing the movement of the medium; it is thus possible to generalize the results obtained in granite, for different media. The problem of estimating the damage caused at a greater distance from the explosion is considered. (authors) [French] Les degats sur diverses structures, constructions, habitations, equipements mecaniques et materiels electriques provoques par des explosions nucleaires souterraines dans le granite sont decrits. On a indique pour chaque type de materiel ou de construction, les distances limites correspondant a un degre de gravite de dommage observe. Ces distances ont ete reliees a un parametre caracterisant le mouvement du milieu, permettant ainsi de generaliser les resultats obtenus dans le granite, a differents milieux. Le probleme de la prevision des degats en zone lointaine a ete aborde. (auteurs)

Observation and applications of single-electron charge signals in the XENON100 experiment

NARCIS (Netherlands)

Aprile, E.; et al., [Unknown; Alfonsi, M.; Colijn, A.P.; Decowski, M.P.

2014-01-01

The XENON100 dark matter experiment uses liquid xenon in a time projection chamber (TPC) to measure xenon nuclear recoils resulting from the scattering of dark matter weakly interacting massive particles (WIMPs). In this paper, we report the observation of single-electron charge signals which are

Occupational exposure to xenon-133 among hospital workers

International Nuclear Information System (INIS)

Deschamps, M.

1984-11-01

During procedures for pulmonary ventilation studies on patients in hospitals, xenon-133 may escape into ambient air. Measurements of air concentrations were required to permit an evaluation of the exposure to which hospital workers are subjected. Two complementary methods of in situ measurements of air concentrations were employed: a commercial air monitor and evacuated blood sampling tubes. Personal dosimeters (TLDs) were exposed simultaneously with the commercial air monitor, and the results were compared. This report presents the results of the measurements of air concentrations during studies on patients. Substantial leakage of xenon-133 was noted, but workers received less than the maximum permissible dose. Personal dosimeters do not permit accurate evaluation of the skin doses resulting from exposure to xenon-133; measurements of air concentrations are required for such evaluation. A number of procedures are recommended to minimize leakage and personnel exposure

Xenon-induced axial power oscillations in the 400 MW PBMR

International Nuclear Information System (INIS)

Strydom, Gerhard

2008-01-01

The redistribution of the spatial xenon concentration in the 400 MW Pebble Bed Modular Reactor (PBMR) core has a non-linear, time-dependent feedback effect on the spatial power density during several types of operational transient events. Due to the inherent weak coupling that exists between the iodine and xenon formation and destruction rates, as well as the complicating effect of spatial variance in the thermal flux field, reactor cores have been analyzed for a number of decades for the occurrence and severity of xenon-induced axial power oscillations. Of specific importance is the degree of oscillation damping exhibited by the core during transients, which involves axial variations in the local power density. In this paper the TINTE reactor dynamics code is used to assess the stability of the current 400 MW PBMR core design with regard to axial xenon oscillations. The focus is mainly on the determination of the inherent xenon and power oscillation damping properties by utilizing a set of hypothetical control rod insertion transients at various power levels. The oscillation damping properties of two 100%-50%-100% load-follow transients, one of which includes the de-stabilizing axial effects of moving control rods, are also discussed in some detail. The study shows that, although first axial mode oscillations do occur in the 400 MW PBMR core, the inherent damping of these oscillations is high, and that none of the investigated load-follow transients resulted in diverging oscillations. It is also shown that the PBMR core exhibits no radial oscillation components for these xenon-induced axial power oscillations

Modeling the Removal of Xenon from Lithium Hydrate with Aspen HYSYS

Science.gov (United States)

Efthimion, Phillip; Gentile, Charles

2011-10-01

The Laser Inertial Fusion Engine (LIFE) project mission is to provide a long-term, carbon-free source of sustainable energy, in the form of electricity. A conceptual xenon removal system has been modeled with the aid of Aspen HYSYS, a chemical process simulator. Aspen HYSYS provides excellent capability to model chemical flow processes, which generates outputs which includes specific variables such as temperature, pressure, and molar flow. The system is designed to strip out hydrogen isotopes deuterium and tritium. The base design bubbles plasma exhaust laden with x filled with liquid helium. The system separates the xenon from the hydrogen, deuterium, and tritium with a lithium hydrate and a lithium bubbler. After the removal of the hydrogen and its isotopes, the xenon is then purified by way of the process of cryogenic distillation. The pure hydrogen, deuterium, and tritium are then sent to the isotope separation system (ISS). The removal of xenon is an integral part of the laser inertial fusion engine and Aspen HYSYS is an excellent tool to calculate how to create pure xenon.

Output power characteristics of the neutral xenon long laser

Energy Technology Data Exchange (ETDEWEB)

Linford, G.J. [TRW Space and Electronics Group, Redondo Beach, CA (United States). Space and Technology Div.

1994-12-31

Lasers which oscillate within inhomogeneously broadened gain media exhibit spectral hole burning and concomitant reduction in output power compared with equivalent homogeneously-broadened laser gain media. By increasing the cavity length, it may be possible to demonstrate at least a partial transition from an inhomogeneous laser cavity mode spectrum to a homogeneous spectrum. There are a number of high gain laser lines which are inhomogeneously-broadened transitions in electric discharges of neutral xenon. In neutral xenon lasers, as in the cases of many other gas lasers, the inhomogeneous spectral broadening mechanism arises from Doppler shifts, {Delta}{nu}{sub D}, of individual atoms in thermal motion within the electric discharge comprising the laser gain medium. Optical transitions corresponding to these noble gas atoms have natural linewidths, {Delta}{nu}{sub n}{lt}{Delta}{nu}{sub D}. Simulations of the output power characteristics of the xenon laser were carried out as a function of laser cavity parameters, including the cavity length, L. These calculations showed that when the intracavity mode spacing frequency, c/2L{lt}{Delta}{nu}{sub n}, the inhomogeneously broadened xenon mode spectrum converted to a homogeneously broadened oscillation spectrum with an increase in output power. These simulations are compared with experimental results obtained for the long laser oscillation characteristics of the (5d[5/2]{degree}{sub 2}{r_arrow}6p[3/2]{sub 1}) transition corresponding to the strong, high-gain 3.508 {mu} line in xenon.

The physical and physiological aspects of xenon isotopes in nuclear medical applicants

International Nuclear Information System (INIS)

Bolmsjoe, M.

1981-11-01

A method for trapping radioactive xenon waste from nuclear medical departments has been investigated. Adsorption of xenon acivitaded charcoal was found to be an efficient trapping method. A large gain in capacity was found when the trap was refrigerated, and permitted a large number of patient investigations before break-through of xenon occurred. By heating charcoal traps to 250-350 degrees C, adsorbed xenon gas is freed and is thus made available for re-use. A technique for room-air monitoring of xenon-leakage from patient investigations is described, where the room-air is continously pumped through a small charcoal filter, mounted close to a detector. The low gammaenergy of Xe-133, 81 keV, introduces problems for in vivo measurements due to the small differences in the energies of the primary and Compton-scattered photons. Influence of scatter and of hemispheric cross-talk was studied for cerebral blood-flow measurements. It was shown that substantial artefacts are introduced in the calculation of regional gray matter flow. The applicability of the xenon-washout technique for liver blood-flow measurements in rat was investigated. (author)

Xenon Defects in Uranium Dioxide From First Principles and Interatomic Potentials

Science.gov (United States)

Thompson, Alexander

In this thesis, we examine the defect energetics and migration energies of xenon atoms in uranium dioxide (UO2) from first principles and interatomic potentials. We also parameterize new, accurate interatomic potentials for xenon and uranium dioxide. To achieve accurate energetics and provide a foundation for subsequent calculations, we address difficulties in finding consistent energetics within Hubbard U corrected density functional theory (DFT+U). We propose a method of slowly ramping the U parameter in order to guide the calculation into low energy orbital occupations. We find that this method is successful for a variety of materials. We then examine the defect energetics of several noble gas atoms in UO2 for several different defect sites. We show that the energy to incorporate large noble gas atoms into interstitial sites is so large that it is energetically favorable for a Schottky defect cluster to be created to relieve the strain. We find that, thermodynamically, xenon will rarely ever be in the interstitial site of UO2. To study larger defects associated with the migration of xenon in UO 2, we turn to interatomic potentials. We benchmark several previously published potentials against DFT+U defect energetics and migration barriers. Using a combination of molecular dynamics and nudged elastic band calculations, we find a new, low energy migration pathway for xenon in UO2. We create a new potential for xenon that yields accurate defect energetics. We fit this new potential with a method we call Iterative Potential Refinement that parameterizes potentials to first principles data via a genetic algorithm. The potential finds accurate energetics for defects with relatively low amounts of strain (xenon in defect clusters). It is important to find accurate energetics for these sorts of low-strain defects because they essentially represent small xenon bubbles. Finally, we parameterize a new UO2 potential that simultaneously yields accurate vibrational properties

Induction of the lambda bacteriophage synthesis in Escherichia coli K 12 by polonium alpha rays; Induction de la synthese du bacteriophage lambda chez Escherichia coli K 12 par les rayons alpha du polonium

Energy Technology Data Exchange (ETDEWEB)

Devoret, Raymond

1958-06-15

This research thesis reports the study of the inducing action of polonium alpha radiations in Escherichia Coli K 12 by using an external irradiation device. This work comprised the development of a method to spread bacteria in layer with a thickness less than 20 microns, and the measurement of the number of α particles falling on the irradiated surface. This measurement has been performed by using a nuclear emulsion and a simple photographic film. It appears that alpha radiations have an inducing action, and that at most 15 per cent of bacteria can be induced. The comparison of the induction curve with the survival curves of lysogen and sensitive stains shows that there is no abortive induction. Thus, it appears that this inducing action is not due to an indirect effect of the irradiated medium [French] Dans ce travail on a etudie l'action inductrice des rayons alphas du polonium chez Escherichia Coli K 12 par un diapoaitif d'irradiation externe. Son utilisation necessitait: - une methode d'etalement des bacteries en couche de moins de 20 microns d'epaisseur; - une mesure du nombre des particules alpha tombant sur la surface etendue irradiee. Les mesures ont ete faites a l'aide d'une emulsion nucleaire et d'un film photographique ordinaire. 1) Les rayons alphas ont une action inductrice. Au plus 15 pc des bacteries peuvent etre induites. 2) La oomparaison de la courbe d'induction et des courbes de survie des souches lysogene et sensible montre qu'il n'y a pas d'inductions abortives. 3) Cette action inductrice n'est pas due a un effet indirect du milieu irradie. (auteur)

The Large Underground Xenon (LUX) experiment

International Nuclear Information System (INIS)

Akerib, D.S.; Bai, X.; Bedikian, S.; Bernard, E.; Bernstein, A.; Bolozdynya, A.; Bradley, A.; Byram, D.; Cahn, S.B.; Camp, C.; Carmona-Benitez, M.C.; Carr, D.; Chapman, J.J.; Chiller, A.; Chiller, C.; Clark, K.; Classen, T.; Coffey, T.; Curioni, A.

2013-01-01

The Large Underground Xenon (LUX) collaboration has designed and constructed a dual-phase xenon detector, in order to conduct a search for Weakly Interacting Massive Particles (WIMPs), a leading dark matter candidate. The goal of the LUX detector is to clearly detect (or exclude) WIMPS with a spin independent cross-section per nucleon of 2×10 −46 cm 2 , equivalent to ∼1event/100kg/month in the inner 100-kg fiducial volume (FV) of the 370-kg detector. The overall background goals are set to have <1 background events characterized as possible WIMPs in the FV in 300 days of running. This paper describes the design and construction of the LUX detector

Mitigation of {sup 222}Rn induced background in the XENON1T dark matter experiment

Energy Technology Data Exchange (ETDEWEB)

Bruenner, Stefan A.

2017-07-05

{sup 222}Rn is a major source of background in many rare-event experiments such as the XENON1T dark matter search. The noble gas radon is created by radioactive decay inside all detector materials and emanates into the sensitive liquid xenon target disabling any detector shielding. Subsequent beta-decays of radon progenies are the dominant source of background in the XENON1T experiment. In order to mitigate radon induced background the detector's construction materials have been selected according to dedicated {sup 222}Rn emanation measurements. In the first part of this thesis, we summarize the results of the XENON1T radon screening campaign and present the measurement of the integral radon emanation rate of the fully assembled detector. The development of a radon removal system which continuously purifies the liquid xenon target from the emanated radon is the topic of the second part of this thesis. In order to demonstrate the suitability of cryogenic distillation as a technique to separate radon from xenon, we developed an experimental setup to measure the depletion of radon in xenon boil-off gas after a single distillation step. In the last part of the thesis, we demonstrate the operation of a radon removal system for the XENON100 experiment. For this first test employing a running dark matter detector, we integrated a multiple stage, cryogenic distillation column in the XENON100 gas purification loop. From the evolution of the radon concentration in XENON100, we investigate the distillation column's radon removal capability and discuss the design and application of a radon removal system for XENON1T and the upcoming XENONnT experiment.

An absolute nuclear magnetic resonance magnetometer; Magnetometre absolu a resonance magnetique nucleaire

Energy Technology Data Exchange (ETDEWEB)

Salvi, A [Commisariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1961-10-15

After an introduction in which the various work undertaken since the discovery of nuclear magnetic resonance is rapidly reviewed, the author describes briefly In the first chapter three types of NMR magnetometers, giving the advantages and disadvantages of each of them and deducing from this the design of the apparatus having the greatest number of qualities Chapter II is devoted to the crossed coil nuclear oscillator which operates continuously over a wide range (800 gamma). To avoid an error due to a carrying over the frequency, the measurement is carried out using bands of 1000 {gamma}. Chapter III deals with frequency measurements. The author describes an original arrangement which makes possible the frequency-field conversion with an accuracy of {+-} 5 x 10{sup -6}, and the differential measurement between two nuclear oscillators. The report finishes with a conclusion and a few recordings. (author) [French] Apres une introduction rappelant les divers travaux effectues en resonance magnetique nucleaire depuis sa mise en evidence, l'auteur decrit sommairement dans le premier chapitre trois types de magnetometre a R.M.N. enumerant les avantages et les inconvenients de chacun a partir desquels il projet, l'appareillage reunissant le maximum de qualites. Le chapitre II est consacre a l'oscillateur nucleaire a bobines croisees permettant un fonctionnement continu dons une large plage (800 gamma). Pour eviter une erreur due a l'entrainement de frequence, la mesure s'effectue par bandes de 1000 {gamma} chacune. Le chapitre III traite la mesure de frequence. L'auteur expose un montage original permettant la traduction frequence-champ avec une precision egale a {+-} 5.10{sup -6}, et la mesure differentielle entre deux oscillateurs nucleaires. Une conclusion et quelques enregistrements terminent ce travail. (auteur)

Control of spatial xenon oscillations in pressurized water reactors via the Kalman filter

International Nuclear Information System (INIS)

Lin, C.; Lin, Y.J.

1994-01-01

A direct control method is developed to control the spatial xenon oscillations in pressurized water reactors. The xenon and iodine concentration difference between the top and bottom halves of the core is estimated by using the extended Kalman filter (EKF), which is a closed-loop estimation method. The measurement equation used in the observer is the axial offset measurement equation, which reflects the xenon unbalanced effect on the axial offset. Meanwhile, some of the coefficients of the observer are estimated on-line to reduce estimation error resulting from model error, i.e., simplified xenon and iodine dynamics. Therefore, the estimation can be guaranteed to be accurate, and the success of the estimation does not greatly depend on the accuracy of the observer model. The predicted one-step ahead xenon concentration, by using the EKF, was used to calculate the possible axial offset variation, and then the control rod motion was calculated to compensate for it. The simulation results show that the proposed method successfully controls the xenon oscillations

The Staffing of Central Electricity Generating Board Nuclear Power Stations; Organigramme des centrales nucleaires du central electricity generating board; Politika v oblasti kadrov na atomnykh ehlektrostantsiyakh CEGB; El personal de las plantas nucleoelectricas de la central electricity generating board.

Energy Technology Data Exchange (ETDEWEB)

Bartlett, J. S.; Shepherd, G. T. [Central Electricity Generating Board, Western Division, Bristol (United Kingdom)

1963-10-15

An account is given of the staffing requirements and organization at a CEBG nuclear power station. The training of staff and licensing requirements for reactoroperating staff are discussed. Experience gained to data of the outcome of pre-operating training and detailed planning in the operational sphere is given. (author) [French] Le memoire donne un apercu de l'organigramme d'une centrale nucleaire du CEGB et des conditions auxquelles doit satisfaire le personnel (formation, qualifications requises pour la fonction d'operateur). Il rend compte egalement de l'experience acquise a ce jour quant a l'interet qu'il y a a former le personnel au prealable et a etablir des plans d'operation detailles. (author) [Spanish] La memoria informa sobre la organizacion de las centrales nucleoelectricas de la CEGB y sobre la plantilla de personal que estas requieren. Discute la formacion del personal y los requisitos para obtener la licencia de operador de reactores. Describe la experiencia adquirida hasta el presente en materia de formacion previa del personal y de organizacion detallada de las operaciones. (author) [Russian] Daetsya otchet o trebovaniyakh, pred{sup y}avlyaemykh k personalu, i organizatsiya nabora personala na atomnykh ehlektrostantsiyakh Tsentral'nogo upravleniya proizvodstva ehlektroehnergii (CEGB). Obsuzhdayutsya voprosy podgotovki personala i normativnykh trebovanij, pred{sup y}avlyaemykh k ehkspluatatsionnomu personalu. Izlagaetsya opyt, nakoplennyj k nastoyashchemu vremeni v rezul'tate osushchestvleniya predehkspluatatsionnoj podgotovki i podrobnogo planirovaniya v usloviyakh ehkspluatatsii. (author)

A study of filtering problems of background noise in nuclear spectrometry, improvement of signal-to-noise ratio, and of pulse characteristics produced by the optimum predictor device; Etude de problemes de filtrage de bruit de fond en spectrometrie nucleaire, amelioration du rapport signal sur bruit et des caracteristiques de l'impulsion mise en forme par le dispositif du predicteur optimum

Energy Technology Data Exchange (ETDEWEB)

Benda, J [Commissariat a l' Energie Atomique, 91 - Saclay (France). Centre d' Etudes Nucleaires

1967-05-01

The purpose of nuclear spectrometry is the precise measurement of particles energy. The resolving power of a spectrometer design is an important factor. Two main phenomena are involved in the limitation of this resolving power: The statistical fluctuations of the detector itself, and the background noise. For a given noise, the theory of filters enables the calculation of networks specially designed for the improvement of signal to noise ratio. The proposed system should lead to an improvement of 10.5 per cent of this ratio. Experiments have confirmed this theoretical estimation. The predictor device also makes possible the obtaining of shortened pulses. (author) [French] Les mesures en spectrometrie nucleaire ont pour but la determination precise de l'energie des particules. Le pouvoir de resolution d'une chaine de spectrometrie est une caracteristique importante. Deux phenomenes principaux concourent a limiter ce pouvoir de resolution: les fluctuations statistiques du detecteur et le bruit de fond. Pour un bruit de fond donne, la theorie des filtres permet de calculer des reseaux susceptibles de modifier le rapport signal sur bruit. Le systeme propose permet d'ameliorer de 10.5 pour cent ce rapport lorsqu'on se place dans les conditions optimales. Les resultats experimentaux confirment les previsions. Le dispositif predicteur permet aussi un raccourcissement de l'impulsion dans le temps. (auteur)

CRN: 1986 progress report

International Nuclear Information System (INIS)

1987-01-01

Departments activities in high energy physics, nuclear physics, radiation physics and chemistry are reported. Collaboration with university led to creation of SRNU (Service du Reacteur Nucleaire). Vivitron studies are presented [fr

Insights into Earth's Accretion and Mantle Structure from Neon and Xenon in Icelandic Basalt (Invited)

Science.gov (United States)

Mukhopadhyay, S.

2010-12-01

The noble gases provide important constraints for planet accretion models and understanding mantle structure and dynamics. Recent work based on continental well gases indicate that the MORB source 20Ne/22Ne ratio is similar to the Ne-B component in chondrites [1,2]. However, ratios higher than Ne-B have been reported in plume-derived Devonian rocks form the Kola Peninsula [3]. Here I report high-precision noble gas data in an Icelandic basaltic glass that demonstrate plumes have a different 20Ne/22Ne ratio than the MORB source. The highest measured 20Ne/22Ne ratio from Iceland is ~12.9, very similar to values in the Kola plume, but quite distinct from the convecting upper mantle as constrained from the well gases [1,2]. Hence, the Icelandic and Kola plume data indicate that OIBs and MORBs have different 20Ne/22Ne ratios. Since 20Ne/22Ne ratios in the mantle cannot change, Earth must have accreted volatiles from at least two separate reservoirs. The differences in 20Ne/22Ne ratios between OIBs and MORBs further indicate that early heterogeneities in the Earth’s mantle have not been wiped away by 4.5 Gyrs of mantle convection, placing strong constraints on mixing and mass flow in the mantle. The requirement of limited direct mixing between plumes and MORB source is supported by 129Xe, formed through radioactive decay of now extinct 129I. Combined He, Ne, and Xe measurements demonstrate that the Iceland plume has a lower 129Xe/130Xe ratio than MORBs because it evolved with a I/Xe ratio distinct from the MORB source and not because of recycled atmosphere (which has low 129/130Xe) in the plume source. Since 129I became extinct 80 Myrs after solar system formation, limited mixing between plume and MORB source is a stringent requirement. Additionally, the high-precision Xe measurements reveal for the first time that the Iceland plume source has significantly higher proportion of plutonium derived fission xenon than MORBs, requiring the plume source to be less degassed

Automatic control logics to eliminate xenon oscillation based on Axial Offsets Trajectory Method

International Nuclear Information System (INIS)

Shimazu, Yoichiro

1996-01-01

We have proposed Axial Offsets (AO) Trajectory Method for xenon oscillation control in pressurized water reactors. The features of this method are described as such that it can clearly give necessary control operations to eliminate xenon oscillations. It is expected that using the features automatic control logics for xenon oscillations can be simple and be realized easily. We investigated automatic control logics. The AO Trajectory Method could realize a very simple logic only for eliminating xenon oscillations. However it was necessary to give another considerations to eliminate the xenon oscillation with a given axial power distribution. The other control logic based on the modern control theory was also studied for comparison of the control performance of the new control logic. As the results, it is presented that the automatic control logics based on the AO Trajectory Method are very simple and effective. (author)

Non-Destructive Methods for Determining Burn-Up in Nuclear Fuel; Methodes Non Destructives d'Evaluation du Taux de Combustion dans le Combustible Nucleaire; Metody opredeleniya vygoraniya v yadernom toplive bez razrusheniya obraztsa; Metodos No Destructivos para Determinai el Grado de Combustion de los Elementos Combustibles Nucleares

Energy Technology Data Exchange (ETDEWEB)

McGonnagle, W. J. [Illinois Institute of Technology, Chicago, IL (United States)

1966-02-15

is of secondary importance and the cooling time is unimportant. Also, there is more precise nuclear data for the stable fission products. Of the stable isotopes produced during the fission process, zirconium, molybdenum, ruthenium, and neodymium appear to be the most useful. The proposed non-destructive methods using stable isotopes will be discussed. (author) [French] Il est a la fois utile et souhaitable d'utiliser des methodes non destructives pour proceder a la mesure quantitative du taux de combustion des elements combustibles d'un reacteur nucleaire. L'ideal serait de pouvoir analyser le combustible a l'aide d'une methode ne necessitant pas de renseignements particuliers sur les spectres des neutrons, le schema d'irradiation ou le temps de refroidissement. Les isotopes radioactifs et les isotopes stables resultant du processus de fission qui sont presents dans un element combustible irradie caracterisent son irradiation. Malheureusement, que l'analyse soit effectuee au moyen de methodes destructives ou non destructives, les resultats obtenus varient en fonction du spectre de neutrons, du schema d'irradiation et du temps de refroidissement. Deplus, l'absence de donnees nucleaires precises, comme les valeurs des section efficaces, influe sur tous les calculs qui peuvent etre effectues. L'analyse non destructive est egalement genee par la presence de champs de rayonnements intenses qui augmentent le bruit de fond. Il est difficile d'etablir des normes utiles et realistes. Bien que, dans l'etat actuel de la technique, les methodes non destructives n'aient pas toute la precision et l'exactitude voulues, elles presentent neanmoins un grand interet' notamment dans les cas ou il faut obtenir rapidement et economiquement une valeur approximative du taux de combustion. Plusieurs methodes non destructives d'evaluation du taux de combustion sont actuellement appliquees, a l'etude ou en projet. Plusieurs types de spectrometres sont utilises pour la mesure du rayonnement

J129 in the biocycle

International Nuclear Information System (INIS)

Handl, J.; Kuehn, W.

1980-01-01

A brief survey on the few known data on the radioecological behaviour of 129 J is given. Numerous investigations as to the 129 J-uptake in the thyroid of cattle were carried out in the USA. In Western Europe, practically only in the near surroundings of nuclear-technical plants measurements of 129 J were carried out. In the author's opinion, to clarify the ecological behaviour of 129 J, human thyroids should be examined as well, in special regions the share of 129 J in milk, grass, food, and ground-near air should be determined and tests with especially important iodine compounds from various soils and plants should be carried out concerning this re-emissions. (MG) [de

Process for recovering xenon from radioactive gaseous wastes

International Nuclear Information System (INIS)

Kishimoto, Tsuneo.

1980-01-01

Purpose: To recover pure xenon economically and efficiently by amply removing radioactive krypton mixed in xenon without changing the rectifying capacity of an xenon rectifying system itself. Method: Xe containing radioactive Kr(Kr-85) is rectified to reduce the concentration of radioactive Kr. Thereafter, non-radioactive Kr or Ar is added to Xe and further the rectification is carried out. The raw material Xe from the Xe adsorption system of, for example, a radioactive gaseous waste disposal system is cooled to about 100 0 C by a heat-exchanger and thereafter supplied to a rectifying tower to carry out normal rectification of Xe thereby to reduce the concentration of Kr contained in Xe at the tower bottom to the rectification limit concentration. Then, non-radioactive Kr is supplied via a precooler to the tower bottom to continue the rectification, thus the Xe fractions at the tower bottom, in which the concentration of radioactive Kr is reduced, being compressed and recovered. (Kamimura, M.)

Material radioassay and selection for the XENON1T dark matter experiment

Energy Technology Data Exchange (ETDEWEB)

Aprile, E.; Anthony, M.; De Perio, P.; Gao, F.; Goetzke, L.W.; Greene, Z.; Lin, Q.; Messina, M.; Plante, G.; Rizzo, A.; Zhang, Y. [Columbia University, Physics Department, New York, NY (United States); Aalbers, J.; Breur, P.A.; Brown, A.; Colijn, A.P.; Decowski, M.P.; Hogenbirk, E.; Tiseni, A. [Nikhef and the University of Amsterdam, Amsterdam (Netherlands); Agostini, F. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Gran Sasso Science Institute, L' Aquila (Italy); University of Bologna, Department of Physics and Astrophysics, Bologna (Italy); INFN-Bologna (Italy); Alfonsi, M.; Geis, C.; Grignon, C.; Oberlack, U.; Scheibelhut, M.; Schindler, S. [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Amaro, F.D.; Cardoso, J.M.R.; Lopes, J.A.M.; Santos, J.M.F. dos; Silva, M. [University of Coimbra, LIBPhys, Department of Physics, Coimbra (Portugal); Arneodo, F.; Benabderrahmane, M.L.; Maris, I. [New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Barrow, P.; Baudis, L.; Di Giovanni, A.; Franco, D.; Galloway, M.; Kessler, G.; Kish, A.; Mayani, D.; Pakarha, P.; Piastra, F.; Wei, Y.; Wulf, J. [University of Zurich, Physik Institut, Zurich (Switzerland); Bauermeister, B. [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Stockholm University, AlbaNova, Oskar Klein Centre, Department of Physics, Stockholm (Sweden); Berger, T.; Brown, E.; Piro, M.C. [Rensselaer Polytechnic Institute, Department of Physics, Applied Physics and Astronomy, Troy, NY (United States); Sivers, M. von [Rensselaer Polytechnic Institute, Troy, NY (United States). Dept. of Physics, Applied Physics and Astronomy; Bern Univ. (Switzerland). Albert Einstein Center for Fundamental Physics; Bruenner, S.; Cichon, D.; Eurin, G.; Hasterok, C.; Lindemann, S.; Lindner, M.; Marrodan Undagoitia, T.; Pizzella, V.; Rauch, L.; Rupp, N.; Schreiner, J.; Simgen, H. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Bruno, G.; Gallo Rosso, A.; Molinario, A.; Laubenstein, M.; Nisi, S. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Gran Sasso Science Institute, L' Aquila (Italy); Budnik, R.; Itay, R.; Landsman, H.; Lellouch, D.; Levinson, L.; Manfredini, A.; Priel, N. [Weizmann Institute of Science, Department of Particle Physics and Astrophysics, Rehovot (Israel); Buetikofer, L.; Coderre, D.; Kaminsky, B.; Schumann, M. [Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Calven, J.; Conrad, J.; Ferella, A.D.; Pelssers, B. [Stockholm University, AlbaNova, Oskar Klein Centre, Department of Physics, Stockholm (Sweden); Cervantes, M.; Lang, R.F.; Masson, D.; Pienaar, J.; Reichard, S.; Reuter, C. [Purdue University, Department of Physics and Astronomy, West Lafayette, IN (United States); Cussonneau, J.P.; Diglio, S.; Le Calloch, M.; Masbou, J.; Micheneau, K.; Persiani, R.; Thers, D. [Universite de Nantes, SUBATECH, Ecole des Mines de Nantes, CNRS/IN2P3, Nantes (France); Di Gangi, P.; Garbini, M.; Massoli, F.V.; Sartorelli, G.; Selvi, M. [University of Bologna, Department of Physics and Astrophysics, Bologna (Italy); INFN-Bologna (Italy); Fei, J.; Ni, K.; Ye, J. [University of California, Department of Physics, San Diego, CA (United States); Fieguth, A.; Murra, M.; Rosendahl, S.; Weinheimer, C. [Westfaelische Wilhelms-Universitaet Muenster, Institut fuer Kernphysik, Muenster (Germany); Fulgione, W. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Gran Sasso Science Institute, L' Aquila (Italy); INFN-Torino (Italy); Osservatorio Astrofisico di Torino, Torino (Italy); Grandi, L.; Saldanha, R.; Shockley, E.; Upole, N. [University of Chicago, Department of Physics and Kavli Institute of Cosmological Physics, Chicago, IL (United States); Miguez, B.; Trinchero, G. [INFN-Torino (Italy); Osservatorio Astrofisico di Torino, Torino (Italy); Naganoma, J.; Shagin, P. [Rice University, Department of Physics and Astronomy, Houston, TX (United States); Scotto Lavina, L. [Universite Pierre et Marie Curie, Universite Paris Diderot, CNRS/IN2P3, LPNHE, Paris (France); Stein, A.; Wang, H. [University of California, Physics and Astronomy Department, Los Angeles, CA (United States); Tunnell, C. [Nikhef and the University of Amsterdam, Amsterdam (Netherlands); University of Chicago, Department of Physics and Kavli Institute of Cosmological Physics, Chicago, IL (United States); Collaboration: XENON Collaboration

2017-12-15

The XENON1T dark matter experiment aims to detect weakly interacting massive particles (WIMPs) through low-energy interactions with xenon atoms. To detect such a rare event necessitates the use of radiopure materials to minimize the number of background events within the expected WIMP signal region. In this paper we report the results of an extensive material radioassay campaign for the XENON1T experiment. Using gamma-ray spectroscopy and mass spectrometry techniques, systematic measurements of trace radioactive impurities in over one hundred samples within a wide range of materials were performed. The measured activities allowed for stringent selection and placement of materials during the detector construction phase and provided the input for XENON1T detection sensitivity estimates through Monte Carlo simulations. (orig.)

Development of mercury porosimeter. Application to nuclear graphite studies (1961); Mise au point d'un porosimetre a mercure. Application a l'etude des graphites nucleaires (1961)

Energy Technology Data Exchange (ETDEWEB)

Bocquet, M; Genisson, J; Sailleau, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-07-01

A mercury porosimeter, model IFP-CEA, has been developed for application to nuclear graphite studies. The apparatus is based on the capillary depression phenomenon. The relationship between the radius of a pore and the pressure at which mercury fills it is pr = -2 {sigma} cos {theta} ( {sigma} is the surface tension, {theta} the angle of contact of the mercury). After some theoretical consideration, the apparatus is described. The mercury pressure is increased step-wise from 0 to 1000 kg/cm{sup 2} thus yielding the complete distribution of pores from 92 {mu} to 75 A. Results are, then presented concerning nuclear graphites which show the evolution of the porous structure under the effect of bitumen impregnation. In general, the volume of the large pores decreases while that of the small pores increases. The structure of impregnated products appears to depend to a certain extent on that of the starting materials. It has also been possible to study other products with this porosimeter; the range of measurements possible is such that it may be used for the study of the majority of porous materials. (authors) [French] Un porosimetre a mercure modele IFP-CEA a ete mis au point en vue de son application a l'etude de graphites nucleaires. Le fonctionnement de l'appareil repose sur le phenomene de depression capillaire. On etablit la relation existant entre le rayon r d'un pore et la pression p pour laquelle le mercure peut y penetrer: pr = -2 {sigma} cos {theta} ( {sigma} tension superficielle, {theta} angle de contact du mercure). Apres quelques considerations theoriques, l'appareil utilise est decrit. Il permet de faire varier par palier la pression du mercure entre 0 et 1000 kg/cm{sup 2} et d'etablir ainsi la distribution complete des rayons de pores compris entre 92 {mu} et 75 A. Les resultats d'une etude faite sur des graphites nucleaires sont alors presentes faisant apparaitre l'evolution de la structure poreuse sous l'effet des impregnations au brai. D'une facon

Commissioning of the XENON1T liquid level measurement system

Energy Technology Data Exchange (ETDEWEB)

Geis, Christopher [Institut fuer Physik, Johannes Gutenberg-Universitaet, Mainz (Germany)

2016-07-01

Two-phase xenon time projection chambers (TPCs) have been operated very successfully in direct detection experiments for dark matter. This kind of detector uses liquid xenon as the sensitive target and is operated in two-phase (liquid/gas) mode, where the liquid level needs to be monitored and controlled with sub-millimeter precision. We present the installation, commissioning and first measurement data of two kinds of level meters operated in the XENON1T TPC: short level meters are three-plated capacitors measuring the level of the liquid-gas interface with a measurement range h∼5 mm and a resolution of ΔC/h∼1 pF/mm. The long level meters are cylindrical double-walled capacitors, measuring the overall filling level of the XENON1T TPC at a measurement range of h=1.4 m and a resolution of ΔC/h∼0.1 pF/mm. Further, we present the design and programming of the readout electronic based on the UTI chip by Smartec, which allows to read all six levelmeters simultaneously.

Early and long-term mantle processing rates derived from xenon isotopes

Science.gov (United States)

Mukhopadhyay, S.; Parai, R.; Tucker, J.; Middleton, J. L.; Langmuir, C. H.

2015-12-01

Noble gases, particularly xenon (Xe), in mantle-derived basalts provide a rich portrait of mantle degassing and surface-interior volatile exchange. The combination of extinct and extant radioactive species in the I-Pu-U-Xe systems shed light on the degassing history of the early Earth throughout accretion, as well as the long-term degassing of the Earth's interior in association with plate tectonics. The ubiquitous presence of shallow-level air contamination, however, frequently obscures the mantle Xe signal. In a majority of the samples, shallow air contamination dominates the Xe budget. For example, in the gas-rich popping rock 2ΠD43, 129Xe/130Xe ratios reach 7.7±0.23 in individual step-crushes, but the bulk composition of the sample is close to air (129Xe/130Xe of 6.7). Thus, the extent of variability in mantle source Xe composition is not well-constrained. Here, we present new MORB Xe data and explore constraints placed on mantle processing rates by the Xe data. Ten step-crushes were obtained on a depleted popping glass that was sealed in ultrapure N2 after dredge retrieval from between the Kane-Atlantis Fracture Zone of the Mid Atlantic Ridge in May 2012. 9 steps yielded 129Xe/130Xe of 7.50-7.67 and one yielded 7.3. The bulk 129Xe/130Xe of the sample is 7.6, nearly identical to the estimated mantle source value of 7.7 for the sample. Hence, the sample is virtually free of shallow-level air contamination. Because sealing the sample in N2upon dredge retrieval largely eliminated air contamination, for many samples, contamination must be added after sample retrieval from the ocean bottom. Our new high-precision Xe isotopic measurements in upper mantle-derived samples provide improved constraints on the Xe isotopic composition of the mantle source. We developed a forward model of mantle volatile evolution to identify solutions that satisfy our Xe isotopic data. We find that accretion timescales of ~10±5 Myr are consistent with I-Pu-Xe constraints, and the last

Use of the helium-3 proportional counter for neutron spectrometry; Utilisation du compteur proportionnel a helium 3 pour la spectrometrie des neutrons

Energy Technology Data Exchange (ETDEWEB)

Vialettes, H; Le Thanh, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-07-01

Up to now, two methods have been mainly used for neutron spectrometry near nuclear installations: - photographic emulsion spectrometry - the so-called, 'multisphere' technique spectrometry. The first method, which is fairly difficult to apply, has a threshold energy of about 500 keV; this is a big disadvantage for an apparatus which has to be used for spectrometry around nuclear installations where the neutron radiation is very much degraded energetically. The second method does not suffer from this disadvantage but the results which it yields are only approximate. In order to extend the energy range of the neutron spectra studied with sufficient accuracy the use of a helium-3 proportional counter has been considered. This report presents the principles of operation of the helium-3 spectrometer, and the calculation methods which make it possible to take into account the two main effects tending to deform the spectra obtained: - energy absorption by the walls of the counter, - energy loss of the incident neutrons due to elastic collisions with helium-3 nuclei. As an example of the application, the shape of the neutron spectrum emitted by a polonium-lithium source is given; the results obtained are in excellent agreement with theoretical predictions. (authors) [French] Jusqu'ici deux methodes ont ete utilisees principalement pour la spectrometrie des neutrons autour des installations nucleaires: - la spectrometrie par emulsions photographiques - la spectrometrie par la technique dite des multispheres. La premiere methode, d'un emploi assez delicat presente un seuil en energie d'environ 500 keV qui est un obstacle serieux a la spectrometrie autour des installations nucleaires ou le rayonnement neutronique est tres degrade en energie. La deuxieme methode ne presente pas cet inconvenient mais les resultats qu'elle permet d'obtenir ne sont qu'approches. Pour etendre la gamme d'energie des spectres de neutrons etudies avec une precision suffisante, l'utilisation du

Recent developments in evaluating xenon induced flux transients in large HTRs

Energy Technology Data Exchange (ETDEWEB)

Lauer, A.

1974-03-15

A description is provided of the two-dimensional finite-difference xenon code system ASTERIX (A System for Transient Evaluation of Reactor instabilities Induced by Xenon) that was designed for very exact computations of space dependent xenon transients in HTR's and their control. By its modular structure, the code allows for a most flexible use in calculating load following transients, xenon oscillations in x/y, r/z and r/theta geometries and various control operations with either homogeneous poison or discrete rod representations with flux boundary conditions. The most recent upgrade ASTERIX-T includes a detailed temperature feedback option for azimuthal HTR transient calculations, based on an iterative procedure for the evaluation of the power distribution in each time step with succeeding diffusion, temperature and spectrum calculations for the group constants in every spectral region, thus avoiding earlier more problematic approximations of the temperature dependence of the cross sections.

An investigation of axial xenon stability in WWER-1000 reactor designs

International Nuclear Information System (INIS)

Doshi, P.K.; Miller, R.W.

1993-01-01

The nuclear power plants of the WWER-1000 design have experienced frequent xenon oscillation control problems. In most PWRs, xenon oscillations are largely a problem in the axial direction. An one dimensional core model representative of the WWER-1000 design was set up to examine the controllability of the current design. An investigation of possible improvements to this design was made. There was no indication that xenon oscillations were an inherent problem in WWER-1000 core design. Simple changes to the control rod system coupled with a sound power distribution control strategy that has been proven to be an effective but simple procedure to follow, eliminate xenon control problems. The changes proposed can be implemented in a very cost effective manner. There are no equipment changes needed, existing control rods can be used. Only software changes are required. (Z.S.) 1 tab., 2 figs., 7 refs

Nuclear Materials Management and its Relationship to Nuclear Safety and Criticality Control; La Gestion des Matieres Nucleaires et ses Rapports avec la Securite Nucleaire et le Controle de la Criticite; Obrashchenie s yadernymi materialami i ego svyaz' s yadernoj bezopasnost'yu i kontrolem nad kritichnost'yu; La Administracion de Materiales Nucleares y sus Relaciones con la Seguridad Nuclear y el Control de la Criticidad

Energy Technology Data Exchange (ETDEWEB)

Tingey, F. H. [Phillips Petroleum Company, Idaho Falls, ID (United States)

1966-02-15

dictated by the technical considerations and familiar with the operational limitations. The administrative problems are solved through procedural restrictions placed by the supervisor. The NMM office can be most valuable in further support to the supervisor in these activities. The primary responsibility of this office is to alert responsible supervision to potentially hazardous situations as indicated either from information made available through the routine processing of accountability data or from material balance calculations. Any information pertaining to criticality studies as requested from the NMM office must be accurate and precise. A vigorous inventory management policy must be pursued to lessen the problems presented by accumulation of fissile materials. Internal audit by the NMM staff of inventory holdings can also serve to verify adherence to safeguard procedures. A vigorous orientation programme can be implemented by the NMM staff in its dealing with those individuals handling nuclear materials to make them more aware of the hazards involved. The integration of the NMM group into the general criticality safeguard problems at the NRT and has provided an effective system for assisting the line supervision in discharging this very important responsibility. (author) [French] Il est essentiel pour tous ceux qui travaillent dans l'industrie nucleaire de savoir comment eviter que des matieres nucleaires ne se trouvent rassemblees en quantites, selon une geometrie ou dans un milieu tels qu'elles puissent donner lieu a une reaction neutronique en chaine. Ceci interesse tout particulierement ceux qui, dans l'exercice de leurs fonctions, sont responsables de la manipulation, du transfert et de l'entreposage des matieres fissiles. Ces memes personnes participent au systeme de gestion des matieres nucleaires. Elles ont au premier chef la responsabilite de fournir et de recevoir les donnees comptables par l'intermediaire du service de gestion des matieres nucleaires

Review of Development Status of Nuclear Superheat; Expose sur l'etat actuel des travaux concernant la surchauffe nucleaire; Obzor razrabotki voprosa o yadernykh peregrevatelyakh; Estudio de los progresos realizados en niateria de sobrecalentamiento nuclear

Energy Technology Data Exchange (ETDEWEB)

Imhoff, D. H.; Pennington, R. T. [General Electric Company, San Jose, CA (United States)

1963-10-15

fuel irradiation performance, in-pile and out-of-pile uniform and localized corrosion evaluations, results from thermal superheat critical experiments, results from experimental heat-transfer testing and a brief appraisal of the economic incentives of the separate superheat reactor, integral superheat reactor, and mixed-spectrum superheat reactor design studies. (b) A brief description is given of the USAEC-Sponsored ESADA-VESR nuclear superheat fuel development programme. The development tasks, the initial core superheat fuel-element design, the range of experimental variables, and the expected results for the three-year fuel development programme are discussed. (author [French] Depuis 1959, la Societe General Electric s'occupe activement de mettre au point la surchauffe nucleaire dans les reacteurs ralentis a l'eau ordinaire. A cette epoque, le ''Superheat Advance Demonstration Experiment'' (SADE), finance par la societe, a permis d'obtenir, pour la premiere fois aux Etats-Unis, de la vapeur surchauffee par un dispositif nucleaire. Les auteurs du memoire font le point de la situation actuelle concernant la surchauffe nucleaire. Ils decrivent, dans une premiere partie, les trois principales installations de surchauffe nucleaire utilisees par la General Electric et, dans la seconde, les deux principaux programmes de recherches sur la surchauffe ainsi que les resultats les plus importants obtenus jusqu'ici dans ce domaine. 1. Principales installations pour les experiences de surchauffe: a) Breve description du SADE utilise dans le reacteur a eau bouillante de Vallecitos (VBWR), avec tableaux des conditions dans lesquelles se deroulent les experiences, et des elements combustibles irradies pendant la periode comprise entre mai 1959 et juin 1962; puis examen critique des resultats les plus importants ainsi obtenus. b) Breve description de l' ''Expanded Superheat Advance Demonstration Experiment'' (E-SADE) installe dans le reacteur de Vallecitos, avec tableaux des

Xenon migration in UO{sub 2} under irradiation studied by SIMS profilometry

Energy Technology Data Exchange (ETDEWEB)

Marchand, B. [Université de Lyon, CNRS/IN2P3, Université Lyon 1, Institut de Physique Nucléaire de Lyon, 4 rue Enrico Fermi, F-69622 Villeurbanne cedex (France); AREVA, AREVA NP, 10 rue Juliette Récamier, F-69456 Lyon (France); Moncoffre, N. [Université de Lyon, CNRS/IN2P3, Université Lyon 1, Institut de Physique Nucléaire de Lyon, 4 rue Enrico Fermi, F-69622 Villeurbanne cedex (France); Pipon, Y., E-mail: pipon@ipnl.in2p3.fr [Université de Lyon, CNRS/IN2P3, Université Lyon 1, Institut de Physique Nucléaire de Lyon, 4 rue Enrico Fermi, F-69622 Villeurbanne cedex (France); Université de Lyon, Université Lyon 1, IUT Lyon 1, 43 bd du 11 novembre 1918, 69 622 Villeurbanne cedex (France); Bérerd, N. [Université de Lyon, CNRS/IN2P3, Université Lyon 1, Institut de Physique Nucléaire de Lyon, 4 rue Enrico Fermi, F-69622 Villeurbanne cedex (France); Université de Lyon, Université Lyon 1, IUT Lyon 1, 43 bd du 11 novembre 1918, 69 622 Villeurbanne cedex (France); Garnier, C. [AREVA, AREVA NP, 10 rue Juliette Récamier, F-69456 Lyon (France); Raimbault, L. [Ecole des Mines de Paris, Centre de Géosciences, 35 rue Saint Honoré, F-77305 Fontainebleau cedex (France); Sainsot, P. [Université de Lyon, Université Lyon 1, LaMCoS, INSA-Lyon, CNRS UMR5259, F-69621 Villeurbanne cedex (France); and others

2013-09-15

During Pressurized Water Reactor operation, around 25% of the created Fission Products (FP) are Xenon and Krypton. They have a low solubility in the nuclear fuel and can either (i) agglomerate into bubbles which induce mechanical stress in the fuel pellets or (ii) be released from the pellets, increasing the pressure within the cladding and decreasing the thermal conductivity of the gap between pellets and cladding. After fifty years of studies on the nuclear fuel, all mechanisms of Fission Gas Release (FGR) are still not fully understood. This paper aims at studying the FGR mechanisms by decoupling thermal and irradiation effects and by assessing the Xenon behavior for the first time by profilometry. Samples are first implanted with {sup 136}Xe at 800 keV corresponding to a projected range of 140 nm. They are then either annealed in the temperature range 1400–1600 °C, or irradiated with heavy energy ions (182 MeV Iodine) at Room Temperature (RT), 600 °C or 1000 °C. Depth profiles of implanted Xenon in UO{sub 2} are determined by Secondary Ion Mass Spectrometry (SIMS). It is shown that Xenon is mobile during irradiation at 1000 °C. In contrast, thermal treatments do not induce any Xenon migration process: these results are correlated to the formation of Xenon bubbles observed by Transmission Electron Microscopy.

Xenon thermal behavior in sintered titanium nitride, foreseen inert matrix for GFR

International Nuclear Information System (INIS)

Bes, R.

2010-11-01

This work concerns the generation IV future nuclear reactors such as gas-cooled fast reactor (GFR) for which refractory materials as titanium nitride (TiN) are needed to surround fuel and act as a fission product diffusion barrier. This study is about Xe thermal behavior in sintered titanium nitride. Microstructure effects on Xe behavior have been studied. In this purpose, several syntheses have been performed using different sintering temperatures and initial powder compositions. Xenon species have been introduced into samples by ionic implantation. Then, samples were annealed in temperature range from 1300 C to 1600 C, these temperatures being the accidental awaited temperature. A transport of xenon towards sample surface has been observed. Transport rate seems to be slow down when increasing sintering temperature. The composition of initial powder and the crystallographic orientation of each considered grain also influence xenon thermal behavior. Xenon release has been correlated with material oxidation during annealing. Xenon bubbles were observed. Their size is proportional with xenon concentration and increases with annealing temperature. Several mechanisms which could explain Xe intragranular mobility in TiN are proposed. In addition with experiments, very low Xe solubility in TiN has been confirmed by ab initio calculations. So, bi-vacancies were found to be the most favoured Xe incorporation sites in this material. (author)

An approach to stability analysis of spatial xenon oscillations in WWER-1000 reactors

International Nuclear Information System (INIS)

Parhizkari, H.; Aghaie, M.; Zolfaghari, A.; Minuchehr, A.

2015-01-01

Highlights: • The multipoint methodology is developed for xenon oscillation in the BNPP. • The axial, radial and azimuthal offsets are calculated in the BOC and EOC. • It is shown that the all of oscillation modes are safe in the BOC. • The axial oscillation is not safe in the EOC and needs governor control system. • The multipoint kinetics show good agreement for spatial oscillations. - Abstract: Spatial power oscillations due to spatial distribution of xenon transient are well known as xenon oscillation in large reactors. Xenon-induced spatial power oscillations occur as a result of rapid perturbations to power distribution that cause the xenon and iodine distribution to be out of phase with the perturbed power distribution. This results in a shift in xenon and iodine distributions that causes the power distribution to change in an opposite direction from the initial perturbation. In this paper xenon-induced power oscillation is described by a system of differential equations with non-linearity between xenon and flux distributions; the dynamics of process is described by a discrete distributed parameter model, with the neutron flux, the delayed neutrons, the core temperature and the xenon and iodine concentrations as the “states” of the system. It is shown that it is possible to describe the discrete distributed-parameter as a set of coupled point-reactor models. It is also shown that using this scheme it is possible to analyze the control aspects of a multi-section large core reactor by treating only two adjacent sections of the core. To illustrate the capability and efficiency of the proposed scheme Bushehr Nuclear Power Plant, BNPP, which is a WWER-1000 reactor, is chosen to show the performance of the methodology. The axial, azimuthal and radial power oscillation at the beginning of cycle, BOC, and the end of cycle, EOC, for BNPP are investigated; the results are in good agreement with safety analysis report of the reference plant

Requirements for Xenon International

Energy Technology Data Exchange (ETDEWEB)

Hayes, James C.; Ely, James H.

2013-09-26

This document defines the requirements for the new Xenon International radioxenon system. The output of this project will be a Pacific Northwest National Laboratory (PNNL) developed prototype and a manufacturer-developed production prototype. The two prototypes are intended to be as close to matching as possible; this will be facilitated by overlapping development cycles and open communication between PNNL and the manufacturer.

Requirements for Xenon International

Energy Technology Data Exchange (ETDEWEB)

Hayes, James C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ely, James H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Haas, Derek A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Harper, Warren W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Heimbigner, Tom R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hubbard, Charles W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Humble, Paul H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Madison, Jill C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Morris, Scott J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Panisko, Mark E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ripplinger, Mike D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Stewart, Timothy L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2015-12-30

This document defines the requirements for the new Xenon International radioxenon system. The output of this project will be a Pacific Northwest National Laboratory (PNNL) developed prototype and a manufacturer-developed production prototype. The two prototypes are intended to be as close to matching as possible; this will be facilitated by overlapping development cycles and open communication between PNNL and the manufacturer.

Monitoring xenon purity in the LUX detector with a mass spectrometry system

Science.gov (United States)

Balajthy, Jon; LUX Experiment Collaboration

2015-04-01

The LUX dark matter search experiment is a 350 kg two-phase liquid/gas xenon time projection chamber located at the 4850 ft level of the Sanford Underground Research Facility in Lead, SD. To monitor for radioactive impurities such as krypton and impurities which limit charge yield such as oxygen, LUX uses a xenon sampling system consisting of a mass spectrometer and a liquid nitrogen cold trap. The cold trap separates the gaseous impurities from a small sample of xenon and allows them to pass to the mass spectrometer for analysis. We report here on results from the LUX xenon sampling program. We also report on methods to enhance the sensitivity of the cold trap technique in preparation for the next-generation LUX-ZEPLIN experiment which will have even more stringent purity requirements.

Scalability, Scintillation Readout and Charge Drift in a Kilogram Scale Solid Xenon Particle Detector

Energy Technology Data Exchange (ETDEWEB)

Yoo, J. [Fermilab; Cease, H. [Fermilab; Jaskierny, W. F. [Fermilab; Markley, D. [Fermilab; Pahlka, R. B. [Fermilab; Balakishiyeva, D. [Florida U.; Saab, T. [Florida U.; Filipenko, M. [Erlangen - Nuremberg U., ECAP

2014-10-23

We report a demonstration of the scalability of optically transparent xenon in the solid phase for use as a particle detector above a kilogram scale. We employ a liquid nitrogen cooled cryostat combined with a xenon purification and chiller system to measure the scintillation light output and electron drift speed from both the solid and liquid phases of xenon. Scintillation light output from sealed radioactive sources is measured by a set of high quantum efficiency photomultiplier tubes suitable for cryogenic applications. We observed a reduced amount of photons in solid phase compared to that in liquid phase. We used a conventional time projection chamber system to measure the electron drift time in a kilogram of solid xenon and observed faster electron drift speed in the solid phase xenon compared to that in the liquid phase.

Probing the porosity of cocrystallized MCM-49/ZSM-35 zeolites by hyperpolarized 129Xe NMR.

Science.gov (United States)

Liu, Yong; Zhang, Weiping; Xie, Sujuan; Xu, Longya; Han, Xiuwen; Bao, Xinhe

2008-01-31

One- and two-dimensional 129Xe NMR spectroscopy has been employed to study the porosity of cocrystallized MCM-49/ZSM-35 zeolites under the continuous flow of hyperpolarized xenon gas. It is found by variable-temperature experiments that Xe atoms can be adsorbed in different domains of MCM-49/ZSM-35 cocrystallized zeolites and the mechanically mixed counterparts. The exchange of Xe atoms in different types of pores is very fast at ambient temperatures. Even at very low temperature two-dimensional exchange spectra (EXSY) show that Xe atoms still undergo much faster exchange between MCM-49 and ZSM-35 analogues in the cocrystallized zeolites than in the mechanical mixture. This demonstrates that the MCM-49 and ZSM-35 analogues in cocrystallized zeolites may be stacked much closer than in the physical mixture, and some parts of intergrowth may be formed due to the partially similar basic structure of MCM-49 and ZSM-35.

Liquid xenon in nuclear medicine: state-of-the-art and the PETALO approach

Science.gov (United States)

Ferrario, P.

2018-01-01

Liquid xenon has several attractive features, which make it suitable for applications to nuclear medicine, such as high scintillation yield and fast scintillation decay time, better than currently used crystals. Since the '90s, several attempts have been made to build Positron Emission Tomography scanners based on liquid xenon, which can be divided into two different approaches: on one hand, the detection of the ionization charge in TPCs, and, on the other one, the detection of scintillation light with photomultipliers. PETALO (Positron Emission Tof Apparatus with Liquid xenOn) is a novel concept, which combines liquid xenon scintillating cells and silicon photomultipliers for the readout. A first Monte Carlo investigation has pointed out that this technology would provide an excellent intrinsic time resolution, which makes it possible to measure the Time-Of-Flight with high efficiency. Also, the transparency of liquid xenon to UV and blue wavelengths opens the possibility of exploiting both scintillation and Cherenkov light for a high-sensitivity TOF-PET.

Xenon oscillation control in large PWR using a characteristic ellipse trajectory drawn by three axial offsets

International Nuclear Information System (INIS)

Yoichiro, Shimazu

2007-01-01

We have proposed a very simple xenon oscillation control procedure based on a characteristic trajectory. The trajectory is drawn by three offsets of power distributions, namely, AOp, AOi and AOx. They are defined as the offset of axial power distribution, the offset of the power distribution under which the current iodine distribution is obtained as the equilibrium and that for xenon distribution, respectively. When these offsets are plotted on X-Y plane for (AOp-AOx, AOi-AOx) the trajectory shows a quite characteristic ellipse (or an elliptic spiral). It shows characteristics such that the center of the ellipse is at the origin, the gradient of the major axis is constant, direction of the trajectory progress is always anti-clock wise, plot goes around the ellipse during a cycle of the xenon oscillation and so on. This characteristic does not change even if the control rods are moved. When the plot is at the origin of the X-Y plane, no xenon oscillation exists. Using the characteristics of the ellipse the xenon oscillation can be eliminated by guiding the plot to the origin with control rod operation. This concept can be applied not only to the axial xenon oscillation but also to the radial xenon oscillation control. Conventionally, the trajectory is drawn based on the xenon dynamics using reactor parameters such as core averaged macroscopic fission cross section, xenon micro absorption cross section, fission yields of iodine and xenon, and so on together with the neutron flux signals. The accuracy is expected to be better. (authors)

Rapid assessment of pulmonary gas transport with hyperpolarized 129Xe MRI using a 3D radial double golden-means acquisition with variable flip angles.

Science.gov (United States)

Ruppert, Kai; Amzajerdian, Faraz; Hamedani, Hooman; Xin, Yi; Loza, Luis; Achekzai, Tahmina; Duncan, Ian F; Profka, Harrilla; Siddiqui, Sarmad; Pourfathi, Mehrdad; Cereda, Maurizio F; Kadlecek, Stephen; Rizi, Rahim R

2018-04-22

To demonstrate the feasibility of using a 3D radial double golden-means acquisition with variable flip angles to monitor pulmonary gas transport in a single breath hold with hyperpolarized xenon-129 MRI. Hyperpolarized xenon-129 MRI scans with interleaved gas-phase and dissolved-phase excitations were performed using a 3D radial double golden-means acquisition in mechanically ventilated rabbits. The flip angle was either held fixed at 15 ° or 5 °, or it was varied linearly in ascending or descending order between 5 ° and 15 ° over a sampling interval of 1000 spokes. Dissolved-phase and gas-phase images were reconstructed at high resolution (32 × 32 × 32 matrix size) using all 1000 spokes, or at low resolution (22 × 22 × 22 matrix size) using 400 spokes at a time in a sliding-window fashion. Based on these sliding-window images, relative change maps were obtained using the highest mean flip angle as the reference, and aggregated pixel-based changes were tracked. Although the signal intensities in the dissolve-phase maps were mostly constant in the fixed flip-angle acquisitions, they varied significantly as a function of average flip angle in the variable flip-angle acquisitions. The latter trend reflects the underlying changes in observed dissolve-phase magnetization distribution due to pulmonary gas uptake and transport. 3D radial double golden-means acquisitions with variable flip angles provide a robust means for rapidly assessing lung function during a single breath hold, thereby constituting a particularly valuable tool for imaging uncooperative or pediatric patient populations. © 2018 International Society for Magnetic Resonance in Medicine.

Evaluation of activated charcoal for dynamic adsorption of krypton and xenon

International Nuclear Information System (INIS)

Khan, A.A.; Deshingkar, D.S.; Ramarathinam, K.; Kishore, A.G.

1975-01-01

From the standpoint of radiation safety, the release of radioactive krypton and xenon from power reactors should be kept as low as practicable. The decay of shortlived isotopes of krypton and xenon by adsorptive delay on activated charcoal has shown promising results for this purpose. The delay provided by activated charcoal is proportional to the dynamic adsorption coefficients of these gases which are characteristic of the adsorbent. These coefficients were determined for krypton and xenon on indigenous gas-adsorbing activated charcoal at different moisture contents of carrier air stream and activated charcoal, concentrations of krypton around ambient temperatures, to find its suitability for designing adsorber columns. (author)

Spectra of copperlike and zinclike xenon: Xe XXV and Xe XXVI

International Nuclear Information System (INIS)

Kaufman, V.; Sugar, J.; Rowan, W.L.

1988-01-01

The spectra of highly ionized xenon were generated in a tokamak plasma and photographed in the region 60--350 A with a 2.2-m grazing-incidence spectrograph. The 4s 2 --4s4p transitions of Zn-like xenon (Xe XXV) and all the 4l--4(l+1) transitions of Cu-like xenon (Xe XXVI) were measured with estimated uncertainties of +- 0.005 A. These measurements have been combined with previous wavelength measurements of Xe XXVI to determine energy levels. A value for the ionization energy of Xe 25+ of 6 912 400 +- 3000 cm -1 (857.0 +- 0.4 eV) was derived

Operation and technology development of the radioactive xenon and krypton detection equipment

International Nuclear Information System (INIS)

Lee, Wanno; Choi, Sangdo; Ji, Youngyong; Lim, Jong Myoung; Cho, Young Hyun; Kang, Han Beul; Lee, Hoon; Kang, Moon Ja; Choi, Kun Sik

2013-03-01

Operation and technology development of the radioactive xenon and krypton detection equipment - Advancement, independence of operation technology for BfS-IAR system(the simultaneous analysis of xenon and krypton) installed after North Korea nuclear tests in 2006 and establishment of background base-line for xenon and krypton radioactivity. - Enhanced detection and analysis capabilities for neighborhood nuclear activities through advanced research of noble gas detection technology. Results of the Project · The operation of xenon and krypton analysis system (BfS-IAR) · Operation of fixed adsorption system. · Operation of portable adsorption system · Exercise of emergency response and proficiency test with SAUNA. · Measurement of noble gas background at specific region in Korea. - Radioxenon levels at Dongdu Cheon is approximately 1.6 mBq/m 3 · Development of automation filling system for absorber cooling

HEMODYNAMIC EFFECTS OF XENON ANESTHESIA IN CHILDREN

Directory of Open Access Journals (Sweden)

M. V. Bykov

2014-01-01

Full Text Available The study was aimed at hemodynamic effects of xenon on operative interventions in children. Patients and methods: the study involved 30 5-17-year-old children – 10 (33.3% girls and 20 (66.7% boys with ASA score 1-3 admitted for surgical treatment. The children underwent endotracheal anesthesia with xenon-oxygen mixture (Xe:O2 = 60-65:30% and fentanyl (2.5‑3.5  mcg/kg per hour for the following operations: appendectomy – 10 (33.3% patients, herniotomy – 8 (26.7% patients, Ivanissevich procedure – 6 (20.0% patients, plastic surgery of posttraumatic defects of skin and soft tissues – 4 (13.3% patients, abdominal adhesiotomy – 2 (6.7% patients. Central hemodynamics was studied echocardiographically (Philips HD 11, the Netherlands using the Teichholz technique along the cephalocaudal axis (parasternal access. Results: the anesthesia was notable for hemodynamic stability during the operation: as a result, a statistically significant (p < 0.05 increase in systolic, diastolic and mean arterial pressure by 10, 18 and 17%, respectively, was observed. Conclusion: the analysis demonstrated that xenon anesthesia improves lusitropic myocardial function statistically significantly increasing cardiac output by 12% by way of increasing stroke volume by 30%. 

Contribution to the study of molecular movements in cyclohexane by electron spin resonance and electron-nuclear double resonance using a radical probe; Contribution a l'etude des mouvements moleculaires dans le cyclohexane par resonance paramagnetique electronique et double resonance electronique-nucleaire a l'aide d'une sonde radicalaire

Energy Technology Data Exchange (ETDEWEB)

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

1969-07-01

Solutions of stable free radicals of the nitroxide type have been studied as a function of temperature. In the plastic or globular state, the cyclohexane molecules have rapid rotational and diffusional movements. They transmit this movement to dissolved free radicals. Conversely, measurements by electron spin resonance of the absolute movement of the radicals, and by electron nuclear double resonance of their movement relative to the cyclohexane molecules give very precise methods for local analyses of the movement present in the cyclohexane matrix. The principle of these techniques makes up the 'radical probe method'. (author) [French] Des solutions de radicaux libres stables, du type nitroxyde dans le cyclohexane ont ete etudiees, en fonction de la temperature. Les molecules de cyclohexane, dans l'etat plastique ou globulaire, sont animees de mouvements rapides de rotation sur elles-memes et de diffusion. Elles transmettent leur mobilite aux radicaux libres dissous. Reciproquement, la mesure du mouvement absolu des radicaux, a l'aide de la resonance paramagnetique electronique, et celle du mouvement relatif des radicaux et des molecules de cyclohexane par double resonance electronique-nucleaire, constituent des methodes tres precises pour analyser localement les mouvements presents dans la matrice de cyclohexane. Ce principe et ces techniques constituent la 'methode de la sonde radicalaire'. (auteur)

TEM study of xenon bubbles evolution in Xe-implanted Cu. Bubbles shape, epitaxial orientation and adsorption phenomenon

International Nuclear Information System (INIS)

Guillot, J.; Cartraud, M.; Garem, H.; Templier, C.; Desoyer, J.C.

1987-01-01

TEM is used to perform a study of xenon clusters changes in Xe-implanted Cu. After implantation, xenon is gathered into f.c.c. crystalline precipitates with a lattice parameter value of 0.580 nm. During annealing at 600 0 C large (110) facetted bubbles appear (2r≅35 nm) which contain fluid xenon. When cooling down to 100 K, xenon solidifies on bubbles facets in form of a thin membrane. The epitaxial orientations between solid xenon and copper are the same as adsorbed Xe on Cu(110) [fr

I-129 migration and retrospective dosimetry

International Nuclear Information System (INIS)

Daraoui, Abdelouahed

2010-01-01

The naturally occurring of the long-lived radionuclide 129 I (T 1/2 = 15.7 Ma) have been substantially increased by the fallout from atmospheric nuclear explosions, by releases from nuclear accidents and by emissions from reprocessing plants. The aim of this study was to determine the 127 I, 129 I, 40 K and 137 Cs in Soils from Northern Ukraine, Chile, Bavaria and the Retrospective Dosimetry of the 131 I exposure after the Chernobyl Accident. In addition, water samples from North Germany (precipitation, surface and ground waters, Aerosol, soils, Humus and milk), North Sea, North Atlantic, Spitzbergen, Indian Ocean, Mediterranean, Hawaii, Tahiti, Egypt and prenuclear sediment samples of the Baltic Sea and the North Sea were analysed. 129 I/ 127 I was analysed by accelerator mass spectrometry (AMS) and 127 I was determined by inductively coupled plasma mass spectrometry (ICP-MS). The geometric mean deposition density of 129 I in these soils was 109 x 1.5 ±1 mBq m -2 , that the dominant sources of 129 I in the region are the reprocessing plants (La Hague and Sellafield) and not the Chernobyl fallout. The 129 I/ 127 I isotopic ratios of the Bavarian soils are measured between 10 -7 and 10 -10 what is 100- to 1000-time higher than as the ratios obtained for the Chilean samples. The 129 I integral deposition densities in Chile, Easter Island and Antarctica were between 0.3 and 2 mBq m -2 . In these soils the observed 129 I/ 127 I ratios are about 10 -12 low measured Value in the pedosphere. This value is consistent with the results from the marine sediments assumed to represent the pre-nuclear equilibrium ratios. The soils from Chile also allow the determination of the 129 I fallout from the atmospheric nuclear weapons explosions undisturbed from contaminations due to the releases from reprocessing plants. The results from the soil profiles show that more than 90 % of the 129 I-concentration in the soil profiles are still in the top 40 cm of the profiles is located

New constraints and prospects for sub-GeV dark matter scattering off electrons in xenon

Science.gov (United States)

Essig, Rouven; Volansky, Tomer; Yu, Tien-Tien

2017-08-01

We study in detail sub-GeV dark matter scattering off electrons in xenon, including the expected electron recoil spectra and annual modulation spectra. We derive improved constraints using low-energy XENON10 and XENON100 ionization-only data. For XENON10, in addition to including electron-recoil data corresponding to about 1-3 electrons, we include for the first time events corresponding to about 4-7 electrons. Assuming the scattering is momentum independent (FDM=1 ), this strengthens a previous cross-section bound by almost an order of magnitude for dark matter masses above 50 MeV. The available XENON100 data corresponds to events with about 4-50 electrons, and leads to a constraint that is comparable to the XENON10 bound above 50 MeV for FDM=1 . We demonstrate that a search for an annual modulation signal in upcoming xenon experiments (XENON1T, XENONnT, LZ) could substantially improve the above bounds even in the presence of large backgrounds. We also emphasize that in simple benchmark models of sub-GeV dark matter, the dark matter-electron scattering rate can be as high as one event every ten (two) seconds in the XENON1T (XENONnT or LZ) experiments, without being in conflict with any other known experimental bounds. While there are several sources of backgrounds that can produce single- or few-electron events, a large event rate can be consistent with a dark matter signal and should not be simply written off as purely a detector curiosity. This fact motivates a detailed analysis of the ionization-data ("S2") data, taking into account the expected annual modulation spectrum of the signal rate, as well as the DM-induced electron-recoil spectra, which are another powerful discriminant between signal and background.

7 CFR 1260.129 - Customs Service.

Science.gov (United States)

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false Customs Service. 1260.129 Section 1260.129... Promotion and Research Order Definitions § 1260.129 Customs Service. Customs Service means the United States Customs Service of the United States Department of the Treasury. ...

Microscopic simulation of xenon-based optical TPCs in the presence of molecular additives

Science.gov (United States)

Azevedo, C. D. R.; González-Díaz, D.; Biagi, S. F.; Oliveira, C. A. B.; Henriques, C. A. O.; Escada, J.; Monrabal, F.; Gómez-Cadenas, J. J.; Álvarez, V.; Benlloch-Rodríguez, J. M.; Borges, F. I. G. M.; Botas, A.; Cárcel, S.; Carrión, J. V.; Cebrián, S.; Conde, C. A. N.; Díaz, J.; Diesburg, M.; Esteve, R.; Felkai, R.; Fernandes, L. M. P.; Ferrario, P.; Ferreira, A. L.; Freitas, E. D. C.; Goldschmidt, A.; Gutiérrez, R. M.; Hauptman, J.; Hernandez, A. I.; Morata, J. A. Hernando; Herrero, V.; Jones, B. J. P.; Labarga, L.; Laing, A.; Lebrun, P.; Liubarsky, I.; Lopez-March, N.; Losada, M.; Martín-Albo, J.; Martínez-Lema, G.; Martínez, A.; McDonald, A. D.; Monteiro, C. M. B.; Mora, F. J.; Moutinho, L. M.; Vidal, J. Muñoz; Musti, M.; Nebot-Guinot, M.; Novella, P.; Nygren, D.; Palmeiro, B.; Para, A.; Pérez, J.; Querol, M.; Renner, J.; Ripoll, L.; Rodríguez, J.; Rogers, L.; Santos, F. P.; dos Santos, J. M. F.; Serra, L.; Shuman, D.; Simón, A.; Sofka, C.; Sorel, M.; Stiegler, T.; Toledo, J. F.; Torrent, J.; Tsamalaidze, Z.; Veloso, J. F. C. A.; Webb, R.; White, J. T.; Yahlali, N.

2018-01-01

We introduce a simulation framework for the transport of high and low energy electrons in xenon-based optical time projection chambers (OTPCs). The simulation relies on elementary cross sections (electron-atom and electron-molecule) and incorporates, in order to compute the gas scintillation, the reaction/quenching rates (atom-atom and atom-molecule) of the first 41 excited states of xenon and the relevant associated excimers, together with their radiative cascade. The results compare positively with observations made in pure xenon and its mixtures with CO2 and CF4 in a range of pressures from 0.1 to 10 bar. This work sheds some light on the elementary processes responsible for the primary and secondary xenon-scintillation mechanisms in the presence of additives, that are of interest to the OTPC technology.

Environmental concentration and migration of 129I

International Nuclear Information System (INIS)

Brauer, F.P.; Strebin, R.S. Jr.

1982-01-01

Local sources of 129 I suitable for study of migration in the environment are uranium ore bodies for long periods and nuclear fuel reprocessing operations for recent periods. Uranium ores produce 129 I from spontaneous and neutron-induced fission. Nuclear fuel reprocessing has resulted in releases of 129 I to both the atmosphere and the hydrosphere. The long-term fate of surface-deposited and groundwater 129 I was studied. Neutron activation analysis was used to measure the low levels of 129 I and natural 127 I in samples near and remote from nuclear fuel reprocessing facilities. Measurements were made on air samples, vegetation, soil, surface water, groundwater and uranium ore samples. Samples were collected both during reprocessing operations and after reprocessing activities had been discontinued for several years. The 129 I was found to accumulate in the top soil and litter layer. The surface concentrations of 129 I in forest communities were found to be several times higher than for nearby grass communities. The 129 I levels were found to persist in the environment after reprocessing activities had been discontinued. Measurable 129 I was found to be contained in uranium ore samples from a variety of locations and with a range of uranium concentrations. Thus ore bodies constitute a source of 129 I suitable for study of migration over long periods. Iodine-129 has entered surface and groundwater as the result of liquid and atmospheric discharges from nuclear fuel reprocessing facilities. The iodine in water samples was found to be anionic and travel with the water flow. Thus 129 I was found to provide high sensitivity for hydrology tracer studies and radioactivity migration surveillance. Once 129 I enters the hydrosphere it migrates with the water with little or no hold-up by exchange with cationic exchangers such as soil or silt

Charge States of Krypton and Xenon in the Solar Wind

Science.gov (United States)

Bochsler, Peter; Fludra, Andrzej; Giunta, Alessandra

2017-09-01

We calculate charge state distributions of Kr and Xe in a model for two different types of solar wind using the effective ionization and recombination rates provided from the OPEN_ADAS data base. The charge states of heavy elements in the solar wind are essential for estimating the efficiency of Coulomb drag in the inner corona. We find that xenon ions experience particularly low Coulomb drag from protons in the inner corona, comparable to the notoriously weak drag of protons on helium ions. It has been found long ago that helium in the solar wind can be strongly depleted near interplanetary current sheets, whereas coronal mass ejecta are sometimes strongly enriched in helium. We argue that if the extraordinary variability of the helium abundance in the solar wind is due to inefficient Coulomb drag, the xenon abundance must vary strongly. In fact, a secular decrease of the solar wind xenon abundance relative to the other heavier noble gases (Ne, Ar, Kr) has been postulated based on a comparison of noble gases in recently irradiated and ancient samples of ilmenite in the lunar regolith. We conclude that decreasing solar activity and decreasing frequency of coronal mass ejections over the solar lifetime might be responsible for a secularly decreasing abundance of xenon in the solar wind.

46 CFR 129.220 - Basic safety.

Science.gov (United States)

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Basic safety. 129.220 Section 129.220 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS ELECTRICAL INSTALLATIONS General Requirements § 129.220 Basic safety. (a) Electrical equipment and installations must be suitable...

Contribution to the study of molecular movements in cyclohexane by electron spin resonance and electron-nuclear double resonance using a radical probe; Contribution a l'etude des mouvements moleculaires dans le cyclohexane par resonance paramagnetique electronique et double resonance electronique-nucleaire a l'aide d'une sonde radicalaire

Energy Technology Data Exchange (ETDEWEB)

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

1969-07-01

Solutions of stable free radicals of the nitroxide type have been studied as a function of temperature. In the plastic or globular state, the cyclohexane molecules have rapid rotational and diffusional movements. They transmit this movement to dissolved free radicals. Conversely, measurements by electron spin resonance of the absolute movement of the radicals, and by electron nuclear double resonance of their movement relative to the cyclohexane molecules give very precise methods for local analyses of the movement present in the cyclohexane matrix. The principle of these techniques makes up the 'radical probe method'. (author) [French] Des solutions de radicaux libres stables, du type nitroxyde dans le cyclohexane ont ete etudiees, en fonction de la temperature. Les molecules de cyclohexane, dans l'etat plastique ou globulaire, sont animees de mouvements rapides de rotation sur elles-memes et de diffusion. Elles transmettent leur mobilite aux radicaux libres dissous. Reciproquement, la mesure du mouvement absolu des radicaux, a l'aide de la resonance paramagnetique electronique, et celle du mouvement relatif des radicaux et des molecules de cyclohexane par double resonance electronique-nucleaire, constituent des methodes tres precises pour analyser localement les mouvements presents dans la matrice de cyclohexane. Ce principe et ces techniques constituent la 'methode de la sonde radicalaire'. (auteur)

7 CFR 1955.129 - Business brokers.

Science.gov (United States)

2010-01-01

... 7 Agriculture 14 2010-01-01 2009-01-01 true Business brokers. 1955.129 Section 1955.129 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS... Dispose of Inventory Property § 1955.129 Business brokers. The services of business brokers or business...

29 CFR 452.129 - Non-discrimination.

Science.gov (United States)

2010-07-01

... 29 Labor 2 2010-07-01 2010-07-01 false Non-discrimination. 452.129 Section 452.129 Labor Regulations Relating to Labor OFFICE OF LABOR-MANAGEMENT STANDARDS, DEPARTMENT OF LABOR LABOR-MANAGEMENT... DISCLOSURE ACT OF 1959 Election Procedures; Rights of Members § 452.129 Non-discrimination. Further...

Resonance quadripolaire nucleaire dans les halogenures d'actinides, ThBr 4, ThCl 4 ET UCl 4. II. Polymorphisme et transition de phase du premier ordre dans ThBr 4. Resonance du Brome dans UBr 4.

Science.gov (United States)

Gourdji, M.; Péneau, A.; Genet, M.; Guibé, L.

1983-12-01

La poursuite de recherches antérieures a permis de caractériser la résonance quadripolaire du brome dans la phase α de ThBr 4 et d'étudier la variation, en fonction de la température, entre 63 et 295 K, de la fréquence de résonance, ν Q(T), correspondante. Une première analyse des conditions expérimentales du passage de la transition α↔β à 426 C a été faite. La résonance du brome dans UBr 4 a également été observée et l'étude en fonction de la température des fréquences de résonance (il y a deux résonances distinctes pour chacun des deux isotopes du brome dans ce composé) a révélé un comportement inattendu en ce sens que les pentes dν Q/dT des courbes ν Q(T) correspondant aux deux résonances sont de signe contraire.

47 CFR 101.129 - Transmitter location.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Transmitter location. 101.129 Section 101.129... SERVICES Technical Standards § 101.129 Transmitter location. (a) The applicant must determine, prior to... adequate to render the service proposed. In cases of questionable antenna locations, it is desirable to...

14 CFR 129.25 - Airplane security.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airplane security. 129.25 Section 129.25 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS... AND FOREIGN OPERATORS OF U.S.-REGISTERED AIRCRAFT ENGAGED IN COMMON CARRIAGE General § 129.25 Airplane...

Global characteristics of an ATON stationary plasma thruster operating with krypton and xenon

International Nuclear Information System (INIS)

Bugrova, A.I.; Lipatov, A.S.; Solomatina, L.V.; Morozov, A.I.

2002-01-01

Paper contains the experimental results of operation of the ATON plasma thruster operating with krypton and xenon. It is shown that consumption of a working gas for consumption of a working gas the krypton base thrust is higher in contrast to xenon base one at lower efficiency. In case of krypton use one obtained the efficiency constituting ∼ 60% at specific pulse reaching 3000 s. Jet divergence in case of krypton use is ∼ ± 22 deg in contrast to ∼ ± 11 deg in case of xenon use [ru

Optimal control of xenon concentration by observer design under reactor model uncertainty

International Nuclear Information System (INIS)

Cho, Nam Z.; Yang, Chae Y.; Woo, Hae S.

1989-01-01

The state feedback in control theory enjoys many advantages, such as stabilization and improved transient response, which could be beneficially used for control of the xenon oscillation in a power reactor. It is, however, not possible in nuclear reactors to measure the state variables, such as xenon and iodine concentrations. For implementation of the optimal state feedback control law, it is thus necessary to estimate the unmeasurable state variables. This paper uses the Luenberger observer to estimate the xenon and iodine concentrations to be used in a linear quadratic problem with state feedback. To overcome the stiffness problem in reactor kinetics, a singular perturbation method is used

46 CFR 129.350 - Batteries-general.

Science.gov (United States)

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Batteries-general. 129.350 Section 129.350 Shipping... INSTALLATIONS Power Sources and Distribution Systems § 129.350 Batteries—general. (a) Wherever a battery is charged, there must be natural or induced ventilation to dissipate the gases generated. (b) Each battery...

p-process xenon isotope anomalies in stardust grains from meteorites

International Nuclear Information System (INIS)

Ott, U.

2013-01-01

Full text: In measurements on 'bulk' samples of meteorites isotopic variations due to the p-process usually have taken a backseat compared to such in s- or r-isotopes, and, in the best case, can be qualitatively attributed to the p-process, with little to no inferences concerning detailed isotopic yields. The situation is different for grains of stardust that survived in primitive meteorites. In fact, isotopically strange xenon was the key feature that led to the first identification of a stardust mineral, nanodiamonds containing xenon with overabundances of up to a factor of ∼2 in both the r-only (≡H-Xe) and p-only (≡L-Xe) isotopes. Relative excesses of the two r-only isotopes ( 134 Xe, 136 Xe) as well as of the two p-only isotopes ( 124 Xe, 126 Xe) are not equal, hence the processes responsible for HL-xenon must differ from the 'average' r- and p-processes as reflected in solar system abundances. However, while considerable effort has been put into explaining H-Xe, there has been little work on the p-side (L-Xe). Relying on scarce nuclear data, Heymann and Dziczkaniec have studied photodisintegration reactions of Xe and Ba seeds in intermediate zones of supernovae and found that the relative production of the p-Xe isotopes depends sensitively on the yield of the (γ, α) reaction on 128 Ba. Another suggestion - applicable to both the r- and p-anomalies in diamond xenon - is that of a 'rapid separation' between stable Xe isotopes and radioactive precursors produced in the 'standard' p- (as well as r-) process. For the p-isotopes to work, this would require the bulk (87%) of 126 Xe to be produced via the 126 Ba precursor, with a half live of ∼100 minutes, in order to explain the high 124 Xe/ 126 Xe. In contrast to diamond xenon, xenon in silicon carbide contains - besides the component from the s-process in their parent AGB stars - 'almost normal' Xe, with indications for 124 Xe/ 126 Xe being few (∼8)% lower than in solar Xe.

Nuclear biological studies in France; Les etudes de biologie nucleaires en France

Energy Technology Data Exchange (ETDEWEB)

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

1961-07-01

On the occasion of a colloquium on radiobiological research programmes, a number of documents dealing with French accomplishments and projects in this field were collected together. We felt that it would be useful to assemble these papers in one report; although they are brief and leave gaps to be filled in, they provide certain data, give an overall view of the situation, and can also suggest a rough plan for the general policy to adopt in the field of 'nuclear' biological research; i.e. research based on the nuclear tracer method or devoted to the action of ionising radiations. (author) [French] Un colloque sur les programmes de recherche en radiobiologie nous a donne l'occasion de reunir des documents sur les realisations et les projets francais dans ce domaine. Il nous a semble utile de reunir en un rapport l'ensemble de ces documents, qui, malgre leur brievete et malgre les lacunes qu'ils comportent, donnent un certain nombre d'informations, permettent une vue d'ensemble et peuvent dessiner aussi l'ebauche d'une politique coherente en matiere de recherches biologiques 'nucleaires', c'est-a-dire de recherches basees sur la methode des indicateurs nucleaires ou consacrees a l'action des rayonnements ionisants. (auteur)

XENON-133 IN CALIFORNIA, NEVADA, AND UTAH FROM THE CHERNOBYL ACCIDENT (JOURNAL VERSION)

Science.gov (United States)

The accident at the Chernobyl nuclear reactor in the USSR introduced numerous radioactive nuclides into the atmosphere, including the noble gas xenon-133. EPA's Environmental Monitoring Systems Laboratory, Las Vegas, NV, detected xenon-133 from the Chernobyl accident in air sampl...

Surface damage on polycrystalline β-SiC by xenon ion irradiation at high fluence

Science.gov (United States)

Baillet, J.; Gavarini, S.; Millard-Pinard, N.; Garnier, V.; Peaucelle, C.; Jaurand, X.; Duranti, A.; Bernard, C.; Rapegno, R.; Cardinal, S.; Escobar Sawa, L.; De Echave, T.; Lanfant, B.; Leconte, Y.

2018-05-01

Polycrystalline β-silicon carbide (β-SiC) pellets were prepared by Spark Plasma Sintering (SPS). These were implanted at room temperature with 800 keV xenon at ion fluences of 5.1015 and 1.1017 cm-2. Microstructural modifications were studied by electronic microscopy (TEM and SEM) and xenon profiles were determined by Rutherford Backscattering Spectroscopy (RBS). A complete amorphization of the implanted area associated with a significant oxidation is observed for the highest fluence. Large xenon bubbles formed in the oxide phase are responsible of surface swelling. No significant gas release has been measured up to 1017 at.cm-2. A model is proposed to explain the different steps of the oxidation process and xenon bubbles formation as a function of ion fluence.

A new liquid xenon scintillation detector for positron emission tomography

International Nuclear Information System (INIS)

Chepel, V.Yu.

1993-01-01

A new positron-sensitive detector of annihilation photons filled with liquid xenon is proposed for positron emission tomography. Simultaneous detection of both liquid xenon scintillation and ionization current produces a time resolution of < 1 ns and a position resolution in the tangential direction of the tomograph ring is ∼ 1 mm and in the radial direction is ∼ 5 mm. The advantages of a tomograph with new detectors are discussed. New algorithms of Compton scattering can be used. (author)

Communications Received from Certain Member States Regarding Guidelines for Transfers of Nuclear-related Dual-use Equipment, Materials, Software and Related Technology; Communications recues de certains Etats Membres concernant les directives applicables aux transferts d'equipements, de matieres et de logiciels a double usage dans le domaine nucleaire, ainsi que de technologies connexes

Energy Technology Data Exchange (ETDEWEB)

NONE

2006-04-10

The Director General of the International Atomic Energy Agency has received Notes Verbales, dated 1 December 2005, from the Resident Representatives to the Agency of Argentina, Australia, Austria, Belarus, Belgium, Brazil, Bulgaria, Canada, Croatia, Czech Republic, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Japan, Republic of Korea, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, New Zealand, Poland, Portugal, Slovenia, South Africa, Spain, Sweden, Switzerland, Turkey, Ukraine, the United Kingdom of Great Britain and Northern Ireland and the United States of America, relating to transfers of nuclear-related dual-use equipment, materials, software and related technology [French] Le Directeur general de l'Agence internationale de l'energie atomique a recu des notes verbales datees du 1er decembre 2006 des representants permanents aupres de l'Agence des Etats suivants : Afrique du Sud, Allemagne, Argentine, Australie, Autriche, Belarus, Belgique, Bresil, Bulgarie, Canada, Croatie, Espagne, Estonie, Etats-Unis d'Amerique, Finlande, France, Grece, Hongrie, Irlande, Italie, Japon, Lettonie, Lituanie, Luxembourg, Malte, Nouvelle-Zelande, Pays-Bas, Pologne, Portugal, Republique de Coree, Republique tcheque, Royaume-Uni de Grande-Bretagne et d'Irlande du Nord, Slovenie, Suede, Suisse, Turquie et Ukraine, au sujet des transferts d'equipements, de matieres et de logiciels e double usage dans le domaine nucleaire, ainsi que de technologies connexes.

46 CFR 129.390 - Shore power.

Science.gov (United States)

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Shore power. 129.390 Section 129.390 Shipping COAST... Power Sources and Distribution Systems § 129.390 Shore power. Each vessel that has an electrical system operating at more than 50 volts and has provisions for receiving shore power must meet the requirements of...

7 CFR 400.129 - Salary offset.

Science.gov (United States)

2010-01-01

... 7 Agriculture 6 2010-01-01 2010-01-01 false Salary offset. 400.129 Section 400.129 Agriculture... Years § 400.129 Salary offset. (a) Debt collection by salary offset is feasible if: the cost to the Government of collection by salary offset does not exceed the amount of the debt; there are no legal...

Quantification of human lung structure and physiology using hyperpolarized 129Xe.

Science.gov (United States)

Chang, Yulin V; Quirk, James D; Ruset, Iulian C; Atkinson, Jeffrey J; Hersman, F William; Woods, Jason C

2014-01-01

To present in vivo, human validation of a previously proposed method to measure key pulmonary parameters related to lung microstructure and physiology. Some parameters, such as blood-air barrier thickness, cannot be measured readily by any other noninvasive modality. Healthy volunteers (n = 12) were studied in 1.5T and 3T whole body human scanners using hyperpolarized xenon. Xenon uptake by lung parenchyma and blood was measured using a chemical shift saturation recovery sequence. Both dissolved-xenon peaks at 197 ppm and 217-218 ppm were fitted against a model of xenon exchange (MOXE) as functions of exchange time. Parameters related to lung function and structure can be obtained by fitting to this model. The following results were obtained from xenon uptake (averaged over all healthy volunteers): surface-area-to-volume ratio = 210 ± 50 cm(-1) ; total septal wall thickness = 9.2 ± 6.5 μm; blood-air barrier thickness = 1.0 ± 0.3 μm; hematocrit = 27 ± 4%; pulmonary capillary blood transit time = 1.3 ± 0.3 s, in good agreement with literature values from invasive experiments. More detailed fitting results are listed in the text. The initial in vivo human results demonstrate that our proposed methods can be used to noninvasively determine lung physiology by simultaneous quantification of a few important pulmonary parameters. This method is highly promising to become a versatile screening method for lung diseases. Copyright © 2013 Wiley Periodicals, Inc.

Determination of 129I in radioactive wastes

International Nuclear Information System (INIS)

Horvathova, B.; Dulanska, S.; Matel, L.; Remenec, B.; Gardonova, V.

2015-01-01

The goal of this work was to develop and optimize the conditions for the distillation of iodine and its use for determination of 129 I on liquid scintillation spectrometer (LSC). An appropriate distillation apparatus for distillation of iodine was proposed by testing distillation apparatus. A method of cleaning of 129 I from present interferents , e.g. 14 C, 137 Cs, was tested on proposed simple distillation apparatus. High-purity fraction needed for the determination of 129 I was achieved by distillation on liquid scintillation spectrometer TRI CARB 2900TR from Perkin Elmer Company. Optimal energy window (0 - 80) keV was chosen to measure 129 I on liquid scintillation spectrometer. Ultima Gold TM AB was chosen as more appropriate scintillator by testing of two scintillation solutions. Optimized method for determining the 129 I was applied to real samples coming from Bohunice NPP. The combination of precipitation method and method of 129 I purification by distillation is easy and less time consuming separation method for the determination of 129 I compared to conventional methods of separation of 129 I, e.g. by liquid extraction. Measuring method on the LSC spectrometer represents a measurement with a higher detection efficiency (95%) as compared to measurement of low-energy X-ray radiation 129 I (29.6 keV) with X-ray detector Si (Li) 12155 SL with detection efficiency only (1-2)%.

Performance of a cryogenic system prototype for the XENON1T detector

International Nuclear Information System (INIS)

Aprile, E; Budnik, R; Choi, B; Contreras, H A; Giboni, K L; Goetzke, L W; Lang, R F; Lim, K E; Melgarejo, A J; Plante, G; Rizzo, A; Shagin, P

2012-01-01

We have developed an efficient cryogenic system with heat exchange and associated gas purification system as a prototype for the XENON1T experiment. The XENON1T detector will use about 3 tons of liquid xenon (LXe) at a temperature of 175K as target and detection medium for a dark matter search. In this paper we report results on the cryogenic system performance focusing on the dynamics of the gas circulation-purification through a heated getter, at flow rates above 50 Standard Liter per Minute (SLPM). A maximum flow of 114 SLPM has been achieved, and using two heat exchangers in series, a heat exchange efficiency better than 96% has been measured.

Measurement of vascular flow in the brain with the xenon/CT method

International Nuclear Information System (INIS)

Wist, A.O.; Cothran, A.; Fatouros, P.P.; Kishore, P.R.S.

1988-01-01

The authors are proposing a modification of the xenon/CT method that allows measurement of the flow in the different brain vessels. Based on an improved stable xenon/CT method, they developed several additional algorithms to differentiate the vessel flow from tissue flow and from artifacts and noise, which are based on the height, steepness, and other parameters of the detected flow values. The vessel flow maps, together with the tissue flow maps and new composite flow maps of recent patients, demonstrate that the stable xenon/CT technique can be extended to quantify vascular flow in the brain. The diagnostic capability of this method can be further improved by removing the vessel flow from the flow maps

Online {sup 222}Rn removal by cryogenic distillation in the XENON100 experiment

Energy Technology Data Exchange (ETDEWEB)

Aprile, E.; Anthony, M.; De Perio, P.; Gao, F.; Goetzke, L.W.; Greene, Z.; Lin, Q.; Messina, M.; Plante, G.; Rizzo, A.; Zhang, Y. [Columbia University, Physics Department, New York, NY (United States); Aalbers, J.; Breur, P.A.; Brown, A.; Colijn, A.P.; Decowski, M.P.; Hogenbirk, E.; Tiseni, A. [Nikhef and the University of Amsterdam, Science Park, Amsterdam (Netherlands); Agostini, F. [INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, L' Aquila (Italy); University of Bologna, Department of Physics and Astrophysics, Bologna (Italy); INFN-Bologna (Italy); Alfonsi, M.; Geis, C.; Grignon, C.; Oberlack, U.; Scheibelhut, M.; Schindler, S. [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Amaro, F.D.; Cardoso, J.M.R.; Lopes, J.A.M.; Orrigo, S.E.A.; Santos, J.M.F. dos; Silva, M. [University of Coimbra, Department of Physics, Coimbra (Portugal); Arneodo, F.; Benabderrahmane, M.L.; Di Giovanni, A.; Maris, I. [New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Barrow, P.; Baudis, L.; Franco, D.; Galloway, M.; Kessler, G.; Kish, A.; Mayani, D.; Pakarha, P.; Piastra, F.; Wei, Y.; Wulf, J. [University of Zurich, Physik-Institut, Zurich (Switzerland); Bauermeister, B. [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Stockholm University, AlbaNova, Department of Physics, Oskar Klein Centre, Stockholm (Sweden); Berger, T.; Brown, E.; Piro, M.C. [Rensselaer Polytechnic Institute, Department of Physics, Applied Physics and Astronomy, Troy, NY (United States); Bruenner, S.; Cichon, D.; Eurin, G.; Hasterok, C.; Lindner, M.; Undagoitia, T.M.; Pizzella, V.; Rauch, L.; Rupp, N.; Schreiner, J.; Simgen, H. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Bruno, G.; Gallo Rosso, A.; Molinario, A. [INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, L' Aquila (Italy); Budnik, R.; Duchovni, E.; Itay, R.; Landsman, H.; Lellouch, D.; Levinson, L.; Manfredini, A.; Priel, N. [Weizmann Institute of Science, Department of Particle Physics and Astrophysics, Rehovot (Israel); Buetikofer, L.; Coderre, D.; Kaminsky, B.; Schumann, M.; Sivers, M. v. [Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Calven, J.; Conrad, J.; Ferella, A.D.; Pelssers, B. [Stockholm University, AlbaNova, Department of Physics, Oskar Klein Centre, Stockholm (Sweden); Cervantes, M.; Lang, R.F.; Masson, D.; Pienaar, J.; Reichard, S.; Reuter, C. [Purdue University, Department of Physics and Astronomy, West Lafayette, IN (United States); Cussonneau, J.P.; Diglio, S.; Le Calloch, M.; Masbou, J.; Micheneau, K.; Persiani, R.; Thers, D. [Universite de Nantes, SUBATECH, Ecole des Mines de Nantes, CNRS/In2p3, Nantes (France); Di Gangi, P.; Garbini, M.; Massoli, F.V.; Sartorelli, G.; Selvi, M. [University of Bologna, Department of Physics and Astrophysics, Bologna (Italy); INFN, Bologna (Italy); Fei, J.; Ni, K.; Ye, J. [University of California, Department of Physics, San Diego, CA (United States); Fieguth, A.; Murra, M.; Rosendahl, S.; Weinheimer, C. [Westfaelische Wilhelms-Universitaet Muenster, Institut fuer Kernphysik, Muenster (Germany); Fulgione, W. [INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, L' Aquila (Italy); INFN-Torino (Italy); Osservatorio Astrofisico di Torino, Turin (Italy); Grandi, L.; Saldanha, R.; Shockley, E.; Upole, N. [University of Chicago, Department of Physics and Kavli Institute of Cosmological Physics, Chicago, IL (United States); Lindemann, S. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Meng, Y.; Stein, A.; Wang, H. [University of California, Physics and Astronomy Department, Los Angeles, CA (United States); Miguez, B.; Trinchero, G. [INFN-Torino (Italy); Osservatorio Astrofisico di Torino, Turin (Italy); Naganoma, J.; Shagin, P. [Rice University, Department of Physics and Astronomy, Houston, TX (United States); Lavina, L.S. [LPNHE, Universite Pierre et Marie Curie, Universite Paris Diderot, CNRS/IN2P3, Paris (France); Tunnell, C. [Nikhef and the University of Amsterdam, Science Park, Amsterdam (Netherlands); University of Chicago, Department of Physics and Kavli Institute of Cosmological Physics, Chicago, IL (United States); Cristescu, I. [Karlsruhe Institute of Technology, Tritium Laboratory Karlsruhe, Eggenstein-Leopoldshafen (Germany); Collaboration: XENON Collaboration

2017-06-15

We describe the purification of xenon from traces of the radioactive noble gas radon using a cryogenic distillation column. The distillation column was integrated into the gas purification loop of the XENON100 detector for online radon removal. This enabled us to significantly reduce the constant {sup 222}Rn background originating from radon emanation. After inserting an auxiliary {sup 222}Rn emanation source in the gas loop, we determined a radon reduction factor of R > 27 (95% C.L.) for the distillation column by monitoring the {sup 222}Rn activity concentration inside the XENON100 detector. (orig.)

Design and construction of a cryogenic distillation device for removal of krypton for liquid xenon dark matter detectors.

Science.gov (United States)

Wang, Zhou; Bao, Lei; Hao, Xihuan; Ju, Yonglin

2014-01-01

Liquid xenon (Xe) is one of the commendable detecting media for the dark matter detections. However, the small content of radioactive krypton-85 ((85)Kr) always exists in the commercial xenon products. An efficient cryogenic distillation system to remove this krypton (Kr) from commercial xenon products has been specifically designed, developed, and constructed in order to meet the requirements of the dark matter experiments with high- sensitivity and low-background. The content of krypton in regular commercial xenon products can be reduced from 10(-9) to 10(-12), with 99% xenon collection efficiency at maximum flow rate of 5 kg/h (15SLPM). The purified xenon gases produced by this distillation system can be used as the detecting media in the project of Panda X, which is the first dark matter detector developed in China.

Dark matter analysis of XENON100 data and cut development utilizing the novel PAX raw data processor

Energy Technology Data Exchange (ETDEWEB)

Wittweg, Christian [Institut fuer Kernphysik, Westfaelische Wilhelms-Universitaet, Muenster (Germany)

2016-07-01

The XENON100 experiment located at LNGS is aimed at the direct detection of weakly interacting massive particles (WIMPs). It utilizes an ultra-low background dual-phase xenon TPC which yields two separate scintillation signals that facilitate background discrimination and event selection. Limits on various interaction types have been published by the collaboration (Science 349 (2015) 6250, 851-854). In the analysis dark matter candidate events have to pass cuts with respect to data quality, consistency and physical features of the interaction. The former ones are implemented with regard to the used data processor's capabilities for noise discrimination and peak-finding. The Processor for Analyzing Xenon (PAX), developed for the XENON1T experiment, enhances these capabilities compared to XENON100. A greater robustness against noise and an increased peak-identification efficiency open up new opportunities for physically motivated cuts while rendering old ones obsolete. The poster will focus on the implementation of new cuts into the analysis chain. Both PAX and the xenon analysis will be introduced. A planned full-scale dark matter analysis of PAX-processed XENON100 data will be outlined.

Review of xenon-133 production and related problems; Estudio bibliografico de la produccion de xenon-133 y problemas afines

Energy Technology Data Exchange (ETDEWEB)

Barrachina, M; Ropero, M

1980-07-01

A literature survey is given on the production methods of fission xenon-133 and related problems, such as purification, metrological and dosimetric aspects, preparation of isotopic solutions, recycling, etc. 127 references are included. (Author) 127 refs.

Time dependent analysis of Xenon spatial oscillations in small power reactors

International Nuclear Information System (INIS)

Decco, Claudia Cristina Ghirardello

1997-01-01

This work presents time dependent analysis of xenon spatial oscillations studying the influence of the power density distribution, type of reactivity perturbation, power level and core size, using the one-dimensional and three-dimensional analysis with the MID2 and citation codes, respectively. It is concluded that small pressurized water reactors with height smaller than 1.5 m are stable and do not have xenon spatial oscillations. (author)

Separation of Graphitic Line in Debyegram of the Reactor Graphite; Separation de la raie graphitique dans le debyegramme du graphite nucleaire; Otdelenie linii grafita v debaiegramme reaktornogo grafita; Separacion de la linea grafitica en el diagrama de debye del grafito nuclear

Energy Technology Data Exchange (ETDEWEB)

Pandic, B. [Institut Rudjer Boskovio, Zagreb, Yugoslavia (Croatia)

1963-11-15

The author sets forth a method for the determination of crystallite dimensions L{sub c} in reactor graphite. The method consists of the mathematical correction of the diffraction profile (002) obtained by means of a Philips diffractometer with scintillation counter. During the work CuK{sub {beta}} radiation is used. The convenience of using CuK{sub {beta}} radiation rather than that of a CuK{sub {alpha}} doublet is discussed. All instrumental errors except that of the sample adsorption are eliminated using corresponding slits. Sample adsorption is corrected mathematically. Highly symmetrical lines of graphitic and non-graphitic phase could be analytically separated from such corrected line profiles. Experimental error in the determination of the half-height and half-width of these lines does not exceed 5%. (author) [French] On a elabore une methode pour determiner la hauteur moyenne L{sub c} des cristallites du graphite nucleaire. Il s'agit d'une methode mathematique de correction du profil de la raie de diffraction (002), obtenu par le diffractometre Philips avec un compteur a scintillation. On a discute les avantages des rayons CuK{sub {beta}} par rapport au doublet CuK{sub {alpha}}. Le choix des ouvertures elimine toutes les erreurs, sauf l'erreur d'absorption dans les echantillons, que l 'on ecarte mathematiquement. Les raies de diffraction pures et tres symetriques des phases graphitique et non graphitique peuvent etre separees du profil corrige de cette facon. L'incertitude dans la mesure de la demi-largeur de ces raies n'est pas superieure a 5%. (author) [Spanish] El autor de la memoria expone un metodo para determinar la altura media Lc de las cristalitas del grafito nuclear. Consiste en corregir matematicamente el perfil de la linea de difraccion (002) obtenido con un difractometro Philips y un contador de centelleo. En la memoria se explican las ventajas que la radiacion CuK{sub {beta}} ofrece sobre el doblete CuK{sub {alpha}} Si se elige correctamente la

Management modes for iodine-129

International Nuclear Information System (INIS)

White, I.F.; Smith, G.M.

1984-01-01

This study completes a two-stage programme, supported by the Commission of the European Communities, on management modes for iodine-129. The models for the radiological assessment of iodine-129 management modes have been reviewed and, where necessary, revised, and a generic radiological assessment has been carried out using these models. Cost benefit analysis has been demonstrated for a variety of iodine-129 management modes; for a wide range of assumptions, the costs of abatement of atmospheric discharges would be outweighed by the radiological benefits. The cost benefit analysis thus complements and confirms the preliminary conclusion of the previous study: iodine-129 should be trapped to a large extent from the off-gases of a large reprocessing plant and disposed of by other suitable means, in order to ensure that all exposures from this radionuclide are as low as reasonably achievable. Once the major fraction of the iodine-129 throughput of a reprocessing plant has been trapped from the dissolver off-gases, there are unlikely to be strong radiation protection incentives either for further trapping from the dissolver off-gases or for trapping from the vessel off-gases. In a generic study it is not possible to state an optimum choice of process(es) for abatement of atmospheric discharges of iodine-129. This choice must be determined by assessments in the specific context of a particular reprocessing plant, its site, the waste disposal routes that are actually available, and also in the wider context of the management plans for all radioactive wastes at the plant in question

The Use of Research Reactors and Short-Lived Isotopes in the Study of Nuclear-Reactor Fuel Materials; Emploi de Reacteurs de Recherche et de Radioisotopes de Courte Periode dans l'Etude des Combustibles pour Reacteurs Nucleaires; ИСПОЛЬЗОВАНИЕ ИССЛЕДОВАТЕЛЬСКИХ РЕАКТОРОВ И КОРОТКОЖИВУЩИХ ИЗОТОПОВ ПРИ ИЗУЧЕНИИ ТОПЛИВНЫХ МАТЕРИАЛОВ ДЛЯ ЯДЕРННХ РЕАКТОРОВ; Empleo de Reactores de Investigacion y de Isotopos de Periodo Corto en el Estudio de Combustibles Nucleares

Energy Technology Data Exchange (ETDEWEB)

Elleman, T. S.; Townley, C. W.; Sunderman, D. N. [Battelle Memorial Institute, Columbus, OH (United States)

1963-03-15

can often exhibit preferential release of particular elements, rapid fission- product release during temperature changes, and fission-gas release after reactor shutdown. The use of this technique allows fundamental information to be obtained on the performance of prototype fuel materials without the necessity for large testing reactors or high-level cave facilities for handling irradiated specimens. (author) [French] On peut employer avec profit un reacteur de recherche pour etudier la mobilite des produits de fission dans les prototypes de combustibles nucleaires en creant un milieu analogue a celui dans lequel le combustible est appele a fonctionner normalement, et en controlant rigoureusement les conditions de l'experience, tout en prevoyant une certaine souplesse dans le dispositif d'experimentation. Si l'on fait varier les conditions d'irradiation et que l'on procede a une analyse quantitative des produits de fission de courte periode liberes par l'echantillon, on pourra determiner les mecanismes de la liberation des produits de fission et leurs rapports avec les proprietes physiques et chimiques tant du combustible servant d'echantillon que des produits de fission eux-memes. On pourra en outre obtenir des donnees de technogenie utiles sur la valeur brute de la radioactivite liberee et la duree de vie probable du combustible. En regle generale, on irradie les echantillons dans des capsules a double paroi qu'on chauffe et introduit dans la piscine ou dans les canaux d'irradiation du reacteur, les produits de fission volatils liberes etant elimines de la capsule par un gaz de balayage. Etant donne .que le rapport entre la vitesse de degagement et la periode du radioisotope constitue un indice important du mecanisme, on recueille et analyse les gaz de fission- krypton et xenon - dont la periode va de 1,7 s jusqu'a 5,3 d. On determine les gaz rares de courte periode (krypton-89, krypton-91, krypton-92, xenon-137, xenon-138, xenon-139, xenon-140 et xenon-141) en

Determination of local boiling in light water reactors by correlation of the neutron noise; Determination de l'ebullition locale dans les reacteurs a eau legere par correlation du bruit neutronique

Energy Technology Data Exchange (ETDEWEB)

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

1968-07-01

The power limit of swimming-pool type reactors depends on the phenomenon of the appearance of burn-out. In order to determine this limit we have attempted to detect the local boiling which usually occurs before the burn out. Local boiling has been simulated by an electrically heated plate placed in the core of the reactor Siloette. The study of local boiling, which is based on the properties of the correlation functions for the neutron noise of detectors placed in the core, shows that a privileged frequency occurs in the power spectrum of the noise. It is intended in the future to determine the influence of various parameters on this characteristic frequency. (author) [French] La limitation de la puissance des reacteurs nucleaires de type piscine est due au phenomene d'apparition de 'burn out'. Pour determiner cette limitation, nous nous sommes proposes dans ce rapport de detecter l'ebullition locale qui apparait generalement avant le 'burn out'. L'ebullition locale a ete simulee par une plaque chauffee electriquement et placee dans le coeur du reacteur SILOETTE. L'etude de l'ebullition locale, qui est basee sur les proprietes des fonctions de correlation du bruit neutronique de detecteurs places clans le coeur, fait apparaitre une frequence privilegiee dans le spectre de puissance du bruit. On envisage dans l'avenir, de determiner l'influence des divers parametres sur cette frequence caracteristique. (auteur)

Biological Studies with Laser-Polarized ^129Xe

Science.gov (United States)

Tseng, C. H.; Oteiza, E. R.; Wong, G. A.; Walsworth, R. L.; Albert, M. S.; Nascimben, L.; Peled, S.; Sakai, K.; Jolesz, F. A.

1996-05-01

We have studied several biological systems using laser-polarized ^129Xe. In certain tissues magnetic resonance imaging (MRI) using inhaled laser-polarized noble gases may provide images superior to those from conventional proton MRI. High resolution laser-polarized ^3He images of air spaces in the human lung were recently obtained by the Princeton/Duke group. However, ^3He is not very soluble in tissue. Therefore, we are using laser polarized ^129Xe (tissue-soluble), with the long term goal of biomedical functional imaging. We have investigated multi-echo and multi-excitation magnetic resonance detection schemes to exploit the highly non-thermal ^129Xe magnetization produced by the laser polarization technique. We have inhalated live rats with laser-polarized ^129Xe gas and measured three distinct ^129Xe tissue resonances that last 20 to 40 sec. As a demonstration, we obtained a laser polarized ^129Xe image of the human oral cavity. Currently we are measuring the polarization lifetime of ^129Xe dissolved in human blood, the biological transporting medium. These studies and other recent developments will be reported.

Contribution to the study on the flow rate adjustment for gas cooled power reactors (1964); Contributiom a l'etude de reglage du debit pour les reacteurs industriels refroidis par gaz (1964)

Energy Technology Data Exchange (ETDEWEB)

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

1961-06-15

1. This original study firstly defines the problem of the adjustment of the coolant flow rate in a reactor channel as a function of the corresponding heat transfer equations and of the local and temporal neutron flux. The necessity of such an adjustment is pointed out and the modifying parameters are studied. An adjustment study using the envelope of the possible flux curves is developed. A short study on the technology and the economical advantage of this adjustment is presented. Some measurements, made on G-1 and G-2, show the precision one can obtain from adjustment apparatus itself as well as from the complete reactor adjustment system. 2. Evolution of nuclear properties of fuel in an heterogeneous thermal reactor. In the first port of this paper, the phenomena of fuel evolution have been mainly pointed out. Now a bibliographical study more qualitatively than quantitatively has been done. This survey specifies the present theories and relates to a real effective cross section and also yields to the bases of such a nuclear calculation. (author) [French] 1. Cette etude originale definit d'abord le probleme du reglage du debit de refrigerant dans un canal de reacteur en fonction de la formulation du calcul des performances thermodynamiques de ce canal et des variations du flux neutronique dans l'espace et le temps. La necessite du reglage est ensuite mise en evidence et les parametres le modifiant sont etudies. Une methode de reglage, basee sur l'emploi d 'une courbe enveloppe des courbes de flux possibles, est donnee. Une breve etude de la technologie et des incidences economiques du reglage est presentee. Des mesures effectuees sur les reacteurs G-1 et G-2 montrent la precision que l'on peut attendre des dispositifs de reglage comme du reglage d'ensemble du reacteur lui-meme. 2. Evolution des proprietes nucleaires du combustible dans un reacteur heterogene a neutrons thermiques. Les phenomenes d'evolution du combustible tiennent une place importante dans l

Status of the 2D Bayesian analysis of XENON100 data

Energy Technology Data Exchange (ETDEWEB)

Schindler, Stefan [JGU, Staudingerweg 7, 55128 Mainz (Germany)

2015-07-01

The XENON100 experiment is located in the underground laboratory at LNGS in Italy. Since Dark Matter particles will only interact very rarely with normal matter, an environment with ultra low background, which is shielded from cosmic radiation is needed. The standard analysis of XENON100 data has made use of the profile likelihood method (a most frequent approach) and still provides one of the most sensitive exclusion limits to WIMP Dark Matter. Here we present work towards a Bayesian approach to the analysis of XENON100 data, where we attempt to include the measured primary (S1) and secondary (S2) scintillation signals in a more complete way. The background and signal models in the S1-S2 space have to be defined and a corresponding likelihood function, describing these models, has to be constructed.

Dynamic method for the measurement of Young'S modulus. Application to nuclear graphites; Methode de mesure dynamique du module d'Young. Application aux graphites nucleaires

Energy Technology Data Exchange (ETDEWEB)

Pattou, F; Trutt, J C

1963-07-01

A dynamic method has been developed for measuring Young's modulus and the rigidity modulus using the 'Forster Elastomat'. The principle consists in the determination of the resonance frequencies of graphite samples submitted to transverse, longitudinal, and torsional vibrations. The first two modes of vibration make it possible to calculate the elasticity modulus or the Young's modulus E, the third mode makes possible the calculation of the rigidity modulus G. The relationships from which the moduli E and G are measured are given. A systematic study has been made of graphite samples produced by extrusion or compression and submitted afterwards to one or several impregnations with pitch. For graphites made from the same coke by the same method, a linear relationship has been found for Young's modulus as a function of the apparent density. For the same apparent density, graphites made from different starting materials have generally different Young's moduli that bear a relationship to the crystalline characteristics of the material. The measurements of the rigidity modulus C made on different graphites also show the influence of crystallite orientation. (authors) [French] Une methode de mesure dynamique du module d'Young et du module de rigidite du graphite utilisant 'l'Elastomat Forster' a ete mise au point. Le principe consiste a determiner les frequences de resonance d'echantillons de graphite soumis a des vibrations transversales, longitudinales et de torsion. Les deux premiers modes de vibration permettent de calculer le module d'elasticite ou module d'Young E, le troisieme mode de vibration permet de calculer le module de rigidite G. Apres avoir decrit la methode de mesure, on rappelle les relations qui permettent de calculer les modules E et G. L'etude systematique d'echantillons de graphite, fabriques par filage ou pressage et ayant subi eventuellement une ou plusieurs impregnations au brai a ete effectuee. Pour les graphites issus du meme coke et fabriques

Development of a liquid xenon Compton telescope dedicated to functional medical imaging; Etude et developpement d'un telescope compton au xenon liquide dedie a l'imagerie medicale fonctionnelle

Energy Technology Data Exchange (ETDEWEB)

Grignon, C

2007-12-15

Functional imaging is a technique used to locate in three dimensions the position of a radiotracer previously injected in a patient. The two main modalities used for a clinical application to detect tumors, the SPECT and the PET, use solid scintillators as a detection medium. The objective of this thesis was to investigate the possibility of using liquid xenon in order to benefit from the intrinsic properties of this medium in functional imaging. The feasibility study of such a device has been performed by taking into account the technical difficulties specific to the liquid xenon. First of all, simulations of a liquid xenon PET has been performed using Monte-Carlo methods. The results obtained with a large liquid xenon volume are promising : we can expect a reduction of the injected activity of radiotracer, an improvement of the spatial resolution of the image and a parallax free camera. The second part of the thesis was focused on the development of a new concept of medical imaging, the three gamma imaging, based on the use of a new emitter: the 44 scandium. Associated to a classical PET camera, the Compton telescope is used to infer the incoming direction of the third gamma ray by triangulation. Therefore, it is possible to reconstruct the position of each emitter in three dimensions. This work convinced the scientific community to support the construction and characterization of a liquid xenon Compton telescope. The first camera dedicated to small animal imaging should then be operational in 2009. (author)

Treatment of Radioactive Effluents at the Saclay Nuclear Research Centre; Traitement des Effluents Radioactifs au Centre d'Etudes Nucleaires de Saclay; 041e 0414 ; Tratamiento de los Efluentes Radiactivos en el Centro de Energia Nuclear de Saclay

Energy Technology Data Exchange (ETDEWEB)

Wormser, G. [Service de Controle des Radiations et de Genie Radioactif, Commissariat a l' Energie Atomique, Saclay (France)

1960-07-01

The Report Gives The Account Of Four Years' Experience In Operating The Treatment Plant For Effluents From The Saclay Nuclear Research Centre. It Contains Data Relating To The Origin, Volume And Treatment Of Waste. (author) [French] Ce rapport presente un bilan d'exploitation de l'installation de traitement des effluents du Centre d'etudes nucleaires de Saclay depuis quatre ans. On donne des chiffres concernant l'origine des residus, leur volume, leur traitement. (author) [Spanish] El autor hace un balance de explotacion de la instalacion de tratamiento de efluentes del centro de Saclay desde hace cuatro anos, dando las cifras correspondientes al origen de los residuos, a su volumen y a su tratamiento. (author) [Russian] V jetom dokumente podvoditsja itog chetyrehletnej jekspluatacii ustanovki po obrabotke zhidkih othotov v Centre jadernyh issledovanij v Sakle. V doklade privodjatsja dannye o proishozhdenii othodov, jh ob'eme i obrabotke. (author)

X-ray detector for automatic exposure control using ionization chamber filled with xenon gas

CERN Document Server

Nakagawa, A; Yoshida, T

2003-01-01

This report refers to our newly developed X-ray detector for reliable automatic X-ray exposure control, which is to be widely used for X-ray diagnoses in various clinical fields. This new detector utilizes an ionization chamber filled with xenon gas, in contrast to conventional X-ray detectors which use ionization chambers filled with air. Use of xenon gas ensures higher sensitivity and thinner design of the detector. The xenon gas is completely sealed in the chamber, so that the influence of the changes in ambient environments is minimized. (author)

Iodide and xenon enhancement of computed tomography (CT) in multiple sclerosis (MS)

International Nuclear Information System (INIS)

Radue, E.W.; Kendall, B.E.

1978-01-01

The characteristic findings on computed tomography (CT) in multiple sclerosis (MS) are discussed. In a series of 49 cases plain CT was normal in 21 (43%), cerebral atrophy alone was present in 17 (35%) and plaques were visible in 11 (23%). These were most often adjacent to the lateral ventricles (14 plaques) and in the parietal white matter (10 plaques). CT was performed after the intravenous administration of iodide in 16 of these cases. Two patients with low attenuation plaques were scanned with xenon enhancement; the plaques absorbed less xenon than the corresponding contralateral brain substance and additional, previously isodense plaques were revealed. In one case the white matter absorbed much less xenon than normal and its uptake relative to grey matter was reduced. (orig.) [de

Assessment of regional emphysema, air-trapping and Xenon-ventilation using dual-energy computed tomography in chronic obstructive pulmonary disease patients.

Science.gov (United States)

Lee, Sang Min; Seo, Joon Beom; Hwang, Hye Jeon; Kim, Namkug; Oh, Sang Young; Lee, Jae Seung; Lee, Sei Won; Oh, Yeon-Mok; Kim, Tae Hoon

2017-07-01

To compare the parenchymal attenuation change between inspiration/expiration CTs with dynamic ventilation change between xenon wash-in (WI) inspiration and wash-out (WO) expiration CTs. 52 prospectively enrolled COPD patients underwent xenon ventilation dual-energy CT during WI and WO periods and pulmonary function tests (PFTs). The parenchymal attenuation parameters (emphysema index (EI), gas-trapping index (GTI) and air-trapping index (ATI)) and xenon ventilation parameters (xenon in WI (Xe-WI), xenon in WO (Xe-WO) and xenon dynamic (Xe-Dyna)) of whole lung and three divided areas (emphysema, hyperinflation and normal) were calculated on virtual non-contrast images and ventilation images. Pearson correlation, linear regression analysis and one-way ANOVA were performed. EI, GTI and ATI showed a significant correlation with Xe-WI, Xe-WO and Xe-Dyna (EI R = -.744, -.562, -.737; GTI R = -.621, -.442, -.629; ATI R = -.600, -.421, -.610, respectively, p emphysema. • The xenon ventilation change correlates with the parenchymal attenuation change. • The xenon ventilation change shows the difference between three lung areas. • The combination of attenuation and xenon can predict more accurate PFTs.

Ionization yield from electron tracks in liquid xenon

International Nuclear Information System (INIS)

Voronova, T.Ya.; Kipsanov, M.A.; Kruglov, A.A.; Obodovskij, I.M.; Pokachalov, S.G.; Shilov, V.A.; Khristich, E.B.

1989-01-01

Methods for calculating coefficients K β , characterizing ionization yield from electron track in liquid xenon are considered. K β calculation is conducted on the base of experimental data on K parameter characterizing ionization yield from a certain combination of photo-, Compton-and Auger electron tracks. K parameter measurements are conducted in liquid xenon at 170 K temperature within 10-30 keV gamma- and X radiation energy ranges. Calculated dependence of K β and K coefficients on the energy in a wide (5-500 keV) range is presented. K β values obtained can be applied for calculating the energy resolution of a gamma-spectrometer and linearity of its calibration characteristics if the electric field intensity in the spectrometer does not exceed some kV/cm

9 CFR 3.129 - Feeding.

Science.gov (United States)

2010-01-01

... Warmblooded Animals Other Than Dogs, Cats, Rabbits, Hamsters, Guinea Pigs, Nonhuman Primates, and Marine... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Feeding. 3.129 Section 3.129 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL...

Evidence for ancient atmospheric xenon in Archean rocks and implications for the early evolution of the atmosphere

Science.gov (United States)

Pujol, M.; Marty, B.; Burnard, P.; Hofmann, A.

2012-12-01

The initial atmospheric xenon isotopic composition has been much debated over the last 4 decades. A Non radiogenic Earth Atmospheric xenon (NEA-Xe) composition has been proposed to be the best estimate of the initial signature ([1]). NEA-Xe consists of modern atmospheric Xe without fission (131-136Xe) or radioactive decay (129Xe) products. However, the isotope composition of such non-radiogenic xenon is very different to that of potential cosmochemical precursors such as solar or meteoritic Xe, as it is mass-fractionated by up to 3-4 % per amu relative to the potential precursors, and it is also elementally depleted relative to other noble gases. Because the Xe isotopic composition of the Archean appears to be intermediate between that of these cosmochemical end-members and that of the modern atmosphere, we argued that isotopic fractionation of atmospheric xenon did not occur early in Earth's history by hydrodynamic escape, as postulated by all other models ([1], [2], [3]), but instead was a continuous, long term process that lasted during at least the Hadean and Archean eons. Taken at face value, the decrease of the Xe isotopic fractionation from 1.6-2.1 % amu-1 3.5 Ga ago ([4]) to 1 % amu-1 3.0 Ga ago (Ar-Ar age in fluid inclusions trapped in quartz from the same Dresser Formation, [5]) could reflect a secular variation of the atmospheric Xe signature. Nevertheless, up until now, all data showing an isotopic mass fractionation have been measured in rocks and fluids from the same formation (Dresser Formation, Western Australia, aged 3.5 Ga), and have yet to be confirmed in rocks from different locations. In order to better constrain xenon isotopic fractionation of the atmosphere through time, we decided to analyze barites from different ages, geological environments and metamorphism grade. We started this study with barite from the Fig Tree Formation (South Africa, aged 3.26 Ga). This barite was sampled in old mines so have negligible modern exposure time. It is

36 CFR 406.112-406.129 - [Reserved

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false [Reserved] 406.112-406.129 Section 406.112-406.129 Parks, Forests, and Public Property AMERICAN BATTLE MONUMENTS COMMISSION... BATTLE MONUMENTS COMMISSION §§ 406.112-406.129 [Reserved] ...

The formation of scientists and technicians at the 'Centre d'Etudes Nucleaires' at Saclay

International Nuclear Information System (INIS)

Debiesse, J.

1958-01-01

The considerable needs in research workers and scientists which are asked by the nuclear energy obliged the Commissariat a l'Energie atomique to deal with a particular effort to increase the quantitative and qualitative formation of scientists. Most various ways have been used. 1- A National Institute of Nuclear Sciences and Nuclear Techniques was created, by a joint decree of the Prime Minister and the Minister for National Education (june 18, 1957). This Institute of Higher Teaching (250 students) indulges in the following matters: atomic engineering, quantum mechanics, theory and technic of particle accelerators, special metallurgy, radiobiology, thermic and mechanics of fluids. 2- An associated centre of the 'Conservatoire National des Arts et Metiers' was created (200 students) for technical assistants, drawers, etc. 3- In contribution with both electronic industry and Ministry of Work, the Centre d'Etudes Nucleaires contributes to an accelerated formation of technical assistants into Professional Centres. Conclusion: Training of scientists and research workers is one of the most important activities of the Centre d'Etudes Nucleaires de Saclay. Without losing its technical efficiency, it has supplied and varied means adapted to the various purposes that we shall reach. (author) [fr

Dual display of flow/lambda results in xenon CT

International Nuclear Information System (INIS)

Lindstrom, W.W.; Gruenaver, L.M.; Dinewitz, I.J.

1989-01-01

Measurement of cortical blood flow has always been limited by the unavoidable inclusion of white matter and sulcal cerebrospinal fluid (CSF) in selected regions of interest. Xenon CT gives clear separation of anatomy, but precise ROI tracing is time consuming. CSF and gray and white matter have differing xenon solubilities (lambda), however, so the authors produce two-dimensional histograms of flow/lambda values within an ROI encompassing the desired anatomy and select lambda subregions for tissue-specific quantitative flow/lambda means and deviations. They report how this display is dynamic, allowing the physician to roam around the anatomy at will, with 1-second statistical updating

Internal plasma potential measurements of a Hall thruster using xenon and krypton propellant

International Nuclear Information System (INIS)

Linnell, Jesse A.; Gallimore, Alec D.

2006-01-01

For krypton to become a realistic option for Hall thruster operation, it is necessary to understand the performance gap between xenon and krypton and what can be done to reduce it. A floating emissive probe is used with the Plasmadynamics and Electric Propulsion Laboratory's High-speed Axial Reciprocating Probe system to map the internal plasma potential structure of the NASA-173Mv1 Hall thruster [R. R. Hofer, R. S. Jankovsky, and A. D. Gallimore, J. Propulsion Power 22, 721 (2006); and ibid.22, 732 (2006)] using xenon and krypton propellant. Measurements are taken for both propellants at discharge voltages of 500 and 600 V. Electron temperatures and electric fields are also reported. The acceleration zone and equipotential lines are found to be strongly linked to the magnetic-field lines. The electrostatic plasma lens of the NASA-173Mv1 Hall thruster strongly focuses the xenon ions toward the center of the discharge channel, whereas the krypton ions are defocused. Krypton is also found to have a longer acceleration zone than the xenon cases. These results explain the large beam divergence observed with krypton operation. Krypton and xenon have similar maximum electron temperatures and similar lengths of the high electron temperature zone, although the high electron temperature zone is located farther downstream in the krypton case

Nuclear program of Iran. Towards de-escalation of a nuclear crisis. Advisory letter; Nucleair programma van Iran. Naar de-escalatie van een nucleaire crisis. Briefadvies

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-04-15

The Dutch government, partly at the request of the House of Representatives (Second Chamber), the AIV asked to give an opinion about the position of Iran in the region and the role of the nuclear program of Iran in the geopolitical relations, in view of the most recent developments [Dutch] De Nederlandse regering heeft, mede op verzoek van de Tweede Kamer der Staten-Generaal, de AIV gevraagd advies uit te brengen over de positie van Iran in de regio en de rol van het nucleaire programma van Iran in de geopolitieke verhoudingen hierin, mede gelet op de meest recente ontwikkelingen.

Diffusion of hyperpolarized {sup 129}Xe in the lung: a simplified model of {sup 129}Xe septal uptake and experimental results

Energy Technology Data Exchange (ETDEWEB)

Patz, Samuel; Muradyan, Iga; Dabaghyan, Mikayel; Washko, George R; Hatabu, Hiroto; Butler, James P [Center for Pulmonary Functional Imaging, Departments of Radiology and Pulmonary Medicine, Brigham and Women' s Hospital and Harvard Medical School, Boston, MA 02115 (United States); Hrovat, Mirko I, E-mail: patz@bwh.harvard.edu [Mirtech, Inc., Brockton, MA 02301 (United States)

2011-01-15

We used hyperpolarized {sup 129}Xe NMR to measure pulmonary alveolar surface area per unit gas volume S{sub A}/V{sub gas}, alveolar septal thickness h and capillary transit time {tau}, three critical determinants of the lung's primary role as a gas exchange organ. An analytical solution for a simplified diffusion model is described, together with a modification of the xenon transfer contrast imaging technique utilizing 90{sup 0} radio-frequency pulses applied to the dissolved phase, rather than traditional 180{sup 0} pulses. With this approach, three-dimensional (3D) maps of S{sub A}/V{sub gas} were obtained. We measured global S{sub A}/V{sub gas}, h and {tau} in four normal subjects, two subjects with mild interstitial lung disease (ILD) and two subjects with mild chronic obstructive pulmonary disease (COPD). In normals, S{sub A}/V{sub gas} decreased with increasing lung volume from {approx}320 to 80 cm{sup -1}; both h{approx}13 {mu}m and {tau}{approx}1.5 s were relatively constant. For the two ILD subjects, h was, respectively, 36 and 97% larger than normal, quantifying an increased gas/blood tissue barrier; S{sub A}/V{sub gas} and {tau} were normal. The two COPD subjects had S{sub A}/V{sub gas} values {approx}25% that of normals, quantifying septal surface loss in emphysema; h and {tau} were normal. These are the first noninvasive, non-radiation-based, quantitative measurements of h and {tau} in patients with pulmonary disease.

Nuclear biological studies in France; Les etudes de biologie nucleaires en France

Energy Technology Data Exchange (ETDEWEB)

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

1961-07-01

On the occasion of a colloquium on radiobiological research programmes, a number of documents dealing with French accomplishments and projects in this field were collected together. We felt that it would be useful to assemble these papers in one report; although they are brief and leave gaps to be filled in, they provide certain data, give an overall view of the situation, and can also suggest a rough plan for the general policy to adopt in the field of 'nuclear' biological research; i.e. research based on the nuclear tracer method or devoted to the action of ionising radiations. (author) [French] Un colloque sur les programmes de recherche en radiobiologie nous a donne l'occasion de reunir des documents sur les realisations et les projets francais dans ce domaine. Il nous a semble utile de reunir en un rapport l'ensemble de ces documents, qui, malgre leur brievete et malgre les lacunes qu'ils comportent, donnent un certain nombre d'informations, permettent une vue d'ensemble et peuvent dessiner aussi l'ebauche d'une politique coherente en matiere de recherches biologiques 'nucleaires', c'est-a-dire de recherches basees sur la methode des indicateurs nucleaires ou consacrees a l'action des rayonnements ionisants. (auteur)

31 CFR 129.5 - Confidentiality.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Confidentiality. 129.5 Section 129.5 Money and Finance: Treasury Regulations Relating to Money and Finance PORTFOLIO INVESTMENT SURVEY... contain data aggregated in such a way that neither the person supplying the information nor the investor...

22 CFR 129.2 - Definitions.

Science.gov (United States)

2010-04-01

... arranging contracts, purchases, sales or transfers of defense articles or defense services in return for a... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Definitions. 129.2 Section 129.2 Foreign... action that facilitates the manufacture, export, or import or a defense article or defense service...

45 CFR 2490.112-2490.129 - [Reserved

Science.gov (United States)

2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false [Reserved] 2490.112-2490.129 Section 2490.112-2490.129 Public Welfare Regulations Relating to Public Welfare (Continued) JAMES MADISON MEMORIAL... CONDUCTED BY THE JAMES MADISON MEMORIAL FELLOWSHIP FOUNDATION §§ 2490.112-2490.129 [Reserved] ...

Study on Radioecology and Tracer of Iodine-129

International Nuclear Information System (INIS)

Xiaolin, Hou

2004-01-01

Iodine-129 (15.7 Ma) is a naturally occurring radioisotope of iodine. The ratio of 129 I/ 127 I was estimated to be ∼ 10 -12 in the ocean and 10 -11 in the territorial environment in pre-nuclear era, releases from nuclear weapon tests have increased this ratio to ∼ 10 -10 . However, a large amount of iodine-129 was released from various nuclear facilities, and the greatest releases of 129 I are from two European reprocessing plants, especially in recent years. By 1998, 2600 Kg and 220 Kg 129 I have been discharged to the marine environment and atmosphere from La Hague (France) and Sellafield reprocessing plants, respectively. This amount is tens times larger than the total 129 I inventory in the pre-nuclear ocean and weapon test releases. Although there is no significant radiation risk for the human health at present level of 129 I, the continuously increasing production and release of 129 I make the accumulation of 129 I in the environment, immigration, cycle and long term radioecological risk should be give more attention due to its long half-life, high accumulation in human thyroid and high mobility. Iodine is a conservative element in the ocean, the large amount of iodine-129 discharged to the marine system can therefore be used as a oceanographic tracer to study the physical dispersion, mixing and circulative processes of water mass in the ocean. In Riso national laboratory, a radiochemical neutron activation analysis method was developed, using this method the radioecology and tracer of iodine-129 was studied. Some representative works are presented below. (1) Evaluation of radiation exposure of humans to iodine-129. The human and animal thyroids collected from different places, such as Tianjin in China, Gemol in Belarus, Ribe in Denmark, human urine in Denmark, seafood in China were analysed for iodine-129 concentration and 129 I/ 127 I ratio, the exposure level were compared with other places. (2) Reconstruction of radiation dose from I-131 in the

The search for dark matter in xenon: Innovative calibration strategies and novel search channels

Science.gov (United States)

Reichard, Shayne Edward

The direct detection dark matter experiment XENON1T became operational in early 2016, heralding the era of tonne-scale dark matter detectors. Direct detection experiments typically search for elastic scatters of dark matter particles off target nuclei. XENON1T's larger xenon target provides the advantage of stronger dark matter signals and lower background rates compared to its predecessors, XENON10 and XENON100; but, at the same time, calibration of the detector's response to backgrounds with traditional external sources becomes exceedingly more difficult. A 220Rn source is deployed on the XENON100 dark matter detector in order to address the challenges in calibration of tonne-scale liquid noble element detectors. I show that the subsequent 212Pb beta emission can be used for low-energy electronic recoil calibration in searches for dark matter. The isotope spreads throughout the entire active region of the detector, and its activity naturally decays below background level within a week after the source is closed. I find no increase in the activity of the troublesome 222Rn background after calibration. Alpha emitters are also distributed throughout the detector and facilitate calibration of its response to 222Rn. Using the delayed coincidence of 220Rn/216Po, I map for the first time the convective motion of particles in the XENON100 detector. Additionally, I make a competitive measurement of the half-life of 212Po, t1/2=293.9+/-(1.0)stat+/-(0.6)ns. In contrast to the elastic scattering of dark matter particles off nuclei, I explore inelastic scattering where the nucleus is excited to a low-lying state of 10-100 keV, with a subsequent prompt de-excitation. I use the inelastic structure factors for the odd-mass xenon isotopes based on state-of-the-art large-scale shell-model calculations with chiral effective field theory WIMP-nucleon currents, finding that the inelastic channel is comparable to or can dominate the elastic channel for momentum transfers around 150 Me

The atomic energy course of the 'Institut National des Sciences et Techniques nucleaires' at the centre d'Etudes Nucleaires at Saclay; L'enseignement de genie atomique de l'Institut national des Sciences et Techniques nucleaires au Centre d'Etudes nucleaires de Saclay

Energy Technology Data Exchange (ETDEWEB)

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

1958-07-01

foreign students. 8- Annexe: list of courses, practical work, pile projects drawn up by the 1957 students. (author)Fren. [French] 1- Les raisons de sa creation. L'electricite de France et l'industrie interessee par le developpement de l'Energie atomique ont demande au Commissariat a l'Energie atomique de former des ingenieurs capables d'etudier des projets de piles et de diriger leur construction. 2- Recrutement et Droits d'inscription. Les demandes d'inscription ont toujours depasse les possibilites. Cette annee, les cours sont suivis par 74 eleves permanents, dont 20 etrangers, et une centaine d'auditeurs libres. Tous les elevont deja ingenieurs ou nantis de grades universitaires eleves. Droit d'inscription: 250 000 F pour les eleves, 125 000 F pour les auditeurs. 3- Organisation de l'Enseignement. II comprend deux options: physique et chimie et dans chaque option: une centaine de conferences, une trentaine de travaux pratiques, des stages dans les services, l'etude d'un projet de reacteur par un groupe de 4 ou 5 eleves. L'ensemble occupe l'annee universitaire du 1 novembre au 14 juillet. 4- Sanction. Un examen final combinant les notes de deux epreuves theoriques, des travaux pratiques, du stage, et du projet conduit a un diplome d'ingenieur en genie atomique. Il n'est pas cree en realite de nouveaux ingenieurs; une mention nouvelle est seulement ajoutee a un diplome deja acquis. Les resultats ont toujours ete excellents. Le pourcentage des echecs est tres faible. 5- Placement des Diplomes. Ils reviennent tous dans leurs industries d'origine qui ont paye leurs salaires et les droits d'inscription en se privant de leurs services pendant les neuf mois de duree des cours. 6- Creations analogues. Un cours analogue a ete cree au Centre d'Etudes Nucleaires de Grenoble. Tandis que celui de SACLAY s'adresse plus specialement aux ingenieurs deja en fonctions, celui de Grenoble est, en principe, destine aux jeunes ingenieurs sortant des ecoles. 7- Conclusion. L

Development of a liquid xenon Compton telescope dedicated to functional medical imaging

International Nuclear Information System (INIS)

Grignon, C.

2007-12-01

Functional imaging is a technique used to locate in three dimensions the position of a radiotracer previously injected in a patient. The two main modalities used for a clinical application to detect tumors, the SPECT and the PET, use solid scintillators as a detection medium. The objective of this thesis was to investigate the possibility of using liquid xenon in order to benefit from the intrinsic properties of this medium in functional imaging. The feasibility study of such a device has been performed by taking into account the technical difficulties specific to the liquid xenon. First of all, simulations of a liquid xenon PET has been performed using Monte-Carlo methods. The results obtained with a large liquid xenon volume are promising : we can expect a reduction of the injected activity of radiotracer, an improvement of the spatial resolution of the image and a parallax free camera. The second part of the thesis was focused on the development of a new concept of medical imaging, the three gamma imaging, based on the use of a new emitter: the 44 scandium. Associated to a classical PET camera, the Compton telescope is used to infer the incoming direction of the third gamma ray by triangulation. Therefore, it is possible to reconstruct the position of each emitter in three dimensions. This work convinced the scientific community to support the construction and characterization of a liquid xenon Compton telescope. The first camera dedicated to small animal imaging should then be operational in 2009. (author)

Double discharges in unipolar-pulsed dielectric barrier discharge xenon excimer lamps

International Nuclear Information System (INIS)

Liu Shuhai; Neiger, Manfred

2003-01-01

Excitation of dielectric barrier discharge xenon excimer lamps by unipolar short square pulses is studied in this paper. Two discharges with different polarity are excited by each voltage pulse (double discharge phenomenon). The primary discharge occurs at the top or at the rising flank of the applied unipolar square pulse, which is directly energized by the external circuit. The secondary discharge with the reversed polarity occurs at the falling flank or shortly after the falling flank end (zero external voltage) depending on the pulse width, which is energized by the energy stored by memory charges deposited by the primary discharge. Fast-speed ICCD imaging shows the primary discharge has a conic discharge appearance with a channel broadening on the anode side. This channel broadening increases with increasing the pulse top level. Only the anode-side surface discharge is observed in the primary discharge. The surface discharge on the cathode side which is present in bipolar sine voltage excitation is not observed. On the contrary, the secondary discharge has only the cathode-side surface discharge. The surface discharge on the anode side is not observed. The secondary discharge is much more diffuse than the primary discharge. Time-resolved emission measurement of double discharges show the secondary discharge emits more VUV xenon excimer radiation but less infrared (IR) xenon atomic emission than the primary discharge. It was found that the IR xenon atomic emission from the secondary discharge can be reduced by shortening the pulse width. The energy efficiency of unipolar-pulsed xenon excimer lamps (the overall energy efficiency of double discharges) is much higher than that obtained under bipolar sine wave excitation. The output VUV spectrum under unipolar pulse excitation is found to be identical to that under sine wave excitation and independent of injected electric power

46 CFR 129.360 - Semiconductor-rectifier systems.

Science.gov (United States)

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Semiconductor-rectifier systems. 129.360 Section 129.360... INSTALLATIONS Power Sources and Distribution Systems § 129.360 Semiconductor-rectifier systems. (a) Each semiconductor-rectifier system must have an adequate heat-removal system to prevent overheating. (b) If a...

Assessment of regional emphysema, air-trapping and Xenon-ventilation using dual-energy computed tomography in chronic obstructive pulmonary disease patients

International Nuclear Information System (INIS)

Lee, Sang Min; Seo, Joon Beom; Kim, Namkug; Oh, Sang Young; Hwang, Hye Jeon; Lee, Jae Seung; Lee, Sei Won; Oh, Yeon-Mok; Kim, Tae Hoon

2017-01-01

To compare the parenchymal attenuation change between inspiration/expiration CTs with dynamic ventilation change between xenon wash-in (WI) inspiration and wash-out (WO) expiration CTs. 52 prospectively enrolled COPD patients underwent xenon ventilation dual-energy CT during WI and WO periods and pulmonary function tests (PFTs). The parenchymal attenuation parameters (emphysema index (EI), gas-trapping index (GTI) and air-trapping index (ATI)) and xenon ventilation parameters (xenon in WI (Xe-WI), xenon in WO (Xe-WO) and xenon dynamic (Xe-Dyna)) of whole lung and three divided areas (emphysema, hyperinflation and normal) were calculated on virtual non-contrast images and ventilation images. Pearson correlation, linear regression analysis and one-way ANOVA were performed. EI, GTI and ATI showed a significant correlation with Xe-WI, Xe-WO and Xe-Dyna (EI R = -.744, -.562, -.737; GTI R = -.621, -.442, -.629; ATI R = -.600, -.421, -.610, respectively, p < 0.01). All CT parameters showed significant correlation with PFTs except forced vital capacity (FVC). There was a significant difference in GTI, ATI and Xe-Dyna in each lung area (p < 0.01). The parenchymal attenuation change between inspiration/expiration CTs and xenon dynamic change between xenon WI- and WO-CTs correlate significantly. There are alterations in the dynamics of xenon ventilation between areas of emphysema. (orig.)

Assessment of regional emphysema, air-trapping and Xenon-ventilation using dual-energy computed tomography in chronic obstructive pulmonary disease patients

Energy Technology Data Exchange (ETDEWEB)

Lee, Sang Min [University of Ulsan College of Medicine, Division of Cardiothoracic Radiology, Department of Radiology and Research Institute of Radiology, Asan Medical Center, Seoul (Korea, Republic of); Yonsei University College of Medicine, Gangnam Severance Hospital, Department of Radiology, Research Istitute of Radiological Science, Seoul (Korea, Republic of); Seo, Joon Beom; Kim, Namkug; Oh, Sang Young [University of Ulsan College of Medicine, Division of Cardiothoracic Radiology, Department of Radiology and Research Institute of Radiology, Asan Medical Center, Seoul (Korea, Republic of); Hwang, Hye Jeon [University of Ulsan College of Medicine, Division of Cardiothoracic Radiology, Department of Radiology and Research Institute of Radiology, Asan Medical Center, Seoul (Korea, Republic of); Hallym University Sacred Heart Hospital, Department of Radiology, Hallym University College of Medicine, Anyang-si, Gyeonggi-do (Korea, Republic of); Lee, Jae Seung; Lee, Sei Won; Oh, Yeon-Mok [University of Ulsan College of Medicine, Department of Pulmonary and Critical Care Medicine, and Clinical Research Center for Chronic Obstructive Airway Diseases, Asan Medical Center, Seoul (Korea, Republic of); Kim, Tae Hoon [Yonsei University College of Medicine, Gangnam Severance Hospital, Department of Radiology, Research Istitute of Radiological Science, Seoul (Korea, Republic of)

2017-07-15

To compare the parenchymal attenuation change between inspiration/expiration CTs with dynamic ventilation change between xenon wash-in (WI) inspiration and wash-out (WO) expiration CTs. 52 prospectively enrolled COPD patients underwent xenon ventilation dual-energy CT during WI and WO periods and pulmonary function tests (PFTs). The parenchymal attenuation parameters (emphysema index (EI), gas-trapping index (GTI) and air-trapping index (ATI)) and xenon ventilation parameters (xenon in WI (Xe-WI), xenon in WO (Xe-WO) and xenon dynamic (Xe-Dyna)) of whole lung and three divided areas (emphysema, hyperinflation and normal) were calculated on virtual non-contrast images and ventilation images. Pearson correlation, linear regression analysis and one-way ANOVA were performed. EI, GTI and ATI showed a significant correlation with Xe-WI, Xe-WO and Xe-Dyna (EI R = -.744, -.562, -.737; GTI R = -.621, -.442, -.629; ATI R = -.600, -.421, -.610, respectively, p < 0.01). All CT parameters showed significant correlation with PFTs except forced vital capacity (FVC). There was a significant difference in GTI, ATI and Xe-Dyna in each lung area (p < 0.01). The parenchymal attenuation change between inspiration/expiration CTs and xenon dynamic change between xenon WI- and WO-CTs correlate significantly. There are alterations in the dynamics of xenon ventilation between areas of emphysema. (orig.)

Xenon adsorption on geological media and implications for radionuclide signatures.

Science.gov (United States)

Paul, M J; Biegalski, S R; Haas, D A; Jiang, H; Daigle, H; Lowrey, J D

2018-07-01

The detection of radioactive noble gases is a primary technology for verifying compliance with the pending Comprehensive Nuclear-Test-Ban Treaty. A fundamental challenge in applying this technology for detecting underground nuclear explosions is estimating the timing and magnitude of the radionuclide signatures. While the primary mechanism for transport is advective transport, either through barometric pumping or thermally driven advection, diffusive transport in the surrounding matrix also plays a secondary role. From the study of primordial noble gas signatures, it is known that xenon has a strong physical adsorption affinity in shale formations. Given the unselective nature of physical adsorption, isotherm measurements reported here show that non-trivial amounts of xenon adsorb on a variety of media, in addition to shale. A dual-porosity model is then discussed demonstrating that sorption amplifies the diffusive uptake of an adsorbing matrix from a fracture. This effect may reduce the radioxenon signature down to approximately one-tenth, similar to primordial xenon isotopic signatures. Copyright © 2018 Elsevier Ltd. All rights reserved.

Quantitative analysis technique for Xenon in PWR spent fuel by using WDS

Energy Technology Data Exchange (ETDEWEB)

Kwon, H. M.; Kim, D. S.; Seo, H. S.; Ju, J. S.; Jang, J. N.; Yang, Y. S.; Park, S. D. [KAERI, Daejeon (Korea, Republic of)

2012-01-15

This study includes three processes. First, a peak centering of the X-ray line was performed after a diffraction for Xenon La1 line was installed. Xe La1 peak was identified by a PWR spent fuel sample. Second, standard intensities of Xe was obtained by interpolation of the La1 intensities from a series of elements on each side of xenon. And then Xe intensities across the radial direction of a PWR spent fuel sample were measured by WDS-SEM. Third, the electron and X-ray depth distributions for a quantitative electron probe micro analysis were simulated by the CASINO Monte Carlo program to do matrix correction of a PWR spent fuel sample. Finally, the method and the procedure for local quantitative analysis of Xenon was developed in this study.

Quantitative analysis technique for Xenon in PWR spent fuel by using WDS

International Nuclear Information System (INIS)

Kwon, H. M.; Kim, D. S.; Seo, H. S.; Ju, J. S.; Jang, J. N.; Yang, Y. S.; Park, S. D.

2012-01-01

This study includes three processes. First, a peak centering of the X-ray line was performed after a diffraction for Xenon La1 line was installed. Xe La1 peak was identified by a PWR spent fuel sample. Second, standard intensities of Xe was obtained by interpolation of the La1 intensities from a series of elements on each side of xenon. And then Xe intensities across the radial direction of a PWR spent fuel sample were measured by WDS-SEM. Third, the electron and X-ray depth distributions for a quantitative electron probe micro analysis were simulated by the CASINO Monte Carlo program to do matrix correction of a PWR spent fuel sample. Finally, the method and the procedure for local quantitative analysis of Xenon was developed in this study

XENON100 exclusion limit without considering Leff as a nuisance parameter

Science.gov (United States)

Davis, Jonathan H.; Bœhm, Céline; Oppermann, Niels; Ensslin, Torsten; Lacroix, Thomas

2012-07-01

In 2011, the XENON100 experiment has set unprecedented constraints on dark matter-nucleon interactions, excluding dark matter candidates with masses down to 6 GeV if the corresponding cross section is larger than 10-39cm2. The dependence of the exclusion limit in terms of the scintillation efficiency (Leff) has been debated at length. To overcome possible criticisms XENON100 performed an analysis in which Leff was considered as a nuisance parameter and its uncertainties were profiled out by using a Gaussian likelihood in which the mean value corresponds to the best fit Leff value (smoothly extrapolated to 0 below 3 keVnr). Although such a method seems fairly robust, it does not account for more extreme types of extrapolation nor does it enable us to anticipate how much the exclusion limit would vary if new data were to support a flat behavior for Leff below 3 keVnr, for example. Yet, such a question is crucial for light dark matter models which are close to the published XENON100 limit. To answer this issue, we use a maximum likelihood ratio analysis, as done by the XENON100 Collaboration, but do not consider Leff as a nuisance parameter. Instead, Leff is obtained directly from the fits to the data. This enables us to define frequentist confidence intervals by marginalizing over Leff.

28 CFR 39.112-39.129 - [Reserved

Science.gov (United States)

2010-07-01

... 28 Judicial Administration 1 2010-07-01 2010-07-01 false [Reserved] 39.112-39.129 Section 39.112-39.129 Judicial Administration DEPARTMENT OF JUSTICE ENFORCEMENT OF NONDISCRIMINATION ON THE BASIS OF HANDICAP IN PROGRAMS OR ACTIVITIES CONDUCTED BY THE DEPARTMENT OF JUSTICE §§ 39.112-39.129 [Reserved] ...

Robust nonlinear model predictive control for nuclear power plants in load following operations with bounded xenon oscillations

International Nuclear Information System (INIS)

Eliasi, H.; Menhaj, M.B.; Davilu, H.

2011-01-01

Research highlights: → In this work, a robust nonlinear model predictive control algorithm is developed. → This algorithm is applied to control the power level for load following. → The state constraints are imposed on the predicted trajectory during optimization. → The xenon oscillations are the main constraint for the load following problem. → In this algorithm, xenon oscillations are bounded within acceptable limits. - Abstract: One of the important operations in nuclear power plants is load-following in which imbalance of axial power distribution induces xenon oscillations. These oscillations must be maintained within acceptable limits otherwise the nuclear power plant could become unstable. Therefore, bounded xenon oscillation considered to be a constraint for the load-following operation. In this paper, a robust nonlinear model predictive control for the load-following operation problem is proposed that ensures xenon oscillations are kept bounded within acceptable limits. The proposed controller uses constant axial offset (AO) strategy to maintain xenon oscillations to be bounded. The constant AO is a robust state constraint for load-following problem. The controller imposes restricted state constraints on the predicted trajectory during optimization which guarantees robust satisfaction of state constraints without restoring to a min-max optimization problem. Simulation results show that the proposed controller for the load-following operation is so effective so that the xenon oscillations kept bounded in the given region.

Measurement of Placental Blood Flow with {sup 133}Xe in Normal and Pathological Human Pregnancy; Mesure du Debit Placentaire dans les Grossesses Normales et Pathologiques

Energy Technology Data Exchange (ETDEWEB)

Pontonnier, G.; Delmas, H.; Farre, J.; Favretto, R. [Clinique Obstetricale, Hopital de la Grave, Toulouse (France)

1971-02-15

practical standpoint, it provides one more element for the surveillance of pregnancies involving high foetal risk and makes it possible to study the action of drugs administered to the mother on placental blood flow. (author) [French] La plupart des auteurs s'accordent a reconnaitre l'importance des alterations de la circulation placentaire dans la genese de la souffrance foetale chronique. Or il n'existait pas jusqu'ici de technique qui permette une evaluation quantitative de l'hemodynamique placentaire. Les auteurs presentent une methode de mesure du debit placentaire qui est une application des radioisotopes a la mesure des debits locaux. Ils utilisent le xenon-133 en solution dans du serum physiologique; ce gaz radioactif presente l'avantage d'etre inerte et instantanement diffusible. Apres localisation radiographique ou ultrasonique du placenta, ils injectent par voie trans-abdominale 50 {mu}Ci de xenon dans le placenta. L'enregistrement de la courbe de clearance du xenon-133 est effectue au moyen d'un detecteur a scintillation. La courbe obtenue est en meme temps enregistree sur un inscripteur lineaire et transmise a un calculateur automatique. Les auteurs ont ainsi realise 111 mesures de debit placentaire: 45 dans des grossesses normales, 59 dans des grossesses pathologiques et 7 apres perfusion medicamenteuse. Les mesures effectuees ont permis pour la premiere fois de chiffrer la valeur du debit placentaire chez la femme. Pour les grossesses normales, entre la 32{sup e} et la 41{sup e} semaine, il est de 145 ml/100 g/min. Les mesures effectuees au cours de grossesses pathologiques (hypertension arterielle, dysgravidie, infection urinaire, diabete, grossesse prolongee) ont montre que celles-ci s'accompagnent d'une diminution du debit placentaire statistiquement significative. L'importance de cette diminution est en rapport avec la clinique et l'etat de l'enfant a la naissance. Cette methode de mesure, facilement reproductible chez la meme femme, presente donc un

Optimisation of the measurement protocols of 129I and 129I/127I. Methodology establishment for the measurement in environmental matrices

International Nuclear Information System (INIS)

Frechou, C.

2000-01-01

129 I, is a natural long-lived isotope, with a half-life of 15,7 million years, also artificially produced in nuclear power plant. It is then released in the liquid and gaseous effluents of the nuclear fuel reprocessing plants. 129 I is integrated in all biological compartments at different activity levels, depending on their distance from the emission source and their ability to metabolize iodine. Performances of the different 129 I and 129 I/ 127 I measurement techniques available: Radiochemical Neutron Activation Analysis, Accelerator Mass Spectrometry, direct γ-X spectrometry and liquid scintillation were evaluated. Associated radiochemical preparation steps of the two first techniques were optimized and adapted to the characteristics of the major environmental matrices. In a first step, the radiochemical protocols were developed and validated. In a second step, intercomparison exercises have been lead on various environmental samples presenting different 129 I activity levels. They showed the good agreement between the results given by the three techniques on different environmental matrices with activities between 0,2 and 200 Bq.kg -1 dry weight. As a conclusion, a methodology for the measurement of 129 I and 129 I/ 127 I ratio in environmental samples is proposed. It includes a decisional diagram taking into account the characteristics of the matrices, the detection limits and the answer delay. A study on the losses of 129 I during the calcination of an algae was lead by direct γ-X spectrometry and application studies were made to measure 129 I levels in different biological compartments issued from various locations: 129 I activity interspecific variation in different species of seaweeds from the French channel coast under the relative influence of La Hague, 129 I levels in bovine thyroids from the Cotentin area and 129 I in vegetal samples collected around the nuclear reprocessing plant of Marcoule. (author)

49 CFR 28.112-28.129 - [Reserved

Science.gov (United States)

2010-10-01

... 49 Transportation 1 2010-10-01 2010-10-01 false [Reserved] 28.112-28.129 Section 28.112-28.129 Transportation Office of the Secretary of Transportation ENFORCEMENT OF NONDISCRIMINATION ON THE BASIS OF HANDICAP IN PROGRAMS OR ACTIVITIES CONDUCTED BY THE DEPARTMENT OF TRANSPORTATION §§ 28.112-28.129 [Reserved] ...

Near-infrared scintillation of xenon by 63Ni beta decay

Science.gov (United States)

Yoshimizu, Norimasa; Lal, Amit; Pollock, Clifford R.

2006-07-01

The near-infrared scintillation of xenon gas by the β decay of 37MBq of Ni63 was studied, in the interest of its use in integrated devices for applications such as optical beacons and wavelength calibration. The emission was imaged and analyzed using Spencer's theory of electron penetration using xenon scattering cross sections derived from Thomas-Fermi theory. The total emission was approximately 2×105photons/s at 20kPa and 1×105photons/s at 100kPa. Spectral data show three dominant peaks at 823, 828, and 882nm as well as the formation of metastable states.

The high pressure xenon lamp as a source of radiation

International Nuclear Information System (INIS)

Heerdt, J.A. ter.

1979-01-01

An account is given of an investigation into the radiation properties of a commercially available high pressure xenon lamp (type XBO 900 W) in the spectral range 0.3 to 3 μm. The purpose of the study was to find out whether such a lamp can serve as a (secondary) standard of radiation in spectroscopic and radiometric measurements. The main advantades of the xenon lamp over other secondary standards such as the tungsten strip lamp and the anode of a carbon arc lamp are the high temperature of its discharge and the resulting strong radiation over a broad spectral range. (Auth.)

Visualize Diffusion Map of COPD Rat with Hyperpolarized Xenon MRI%超极化Xenon对慢阻肺的可视化加权成像

Institute of Scientific and Technical Information of China (English)

阮伟伟; 钟俭平; 韩叶清; 孙献平; 叶朝辉; 周欣

2015-01-01

Hyperpolarized3He or129Xe diffusion MRI has been demonstrated as a promising technique for the detection of microanatomical changes in chronic obstructive pulmonary disease (COPD). Compared with 3He,129Xe is more available for the potential clinical applications. However, the measurement of129Xe apparent diffusion coefficient (ADC) possesses more challenges due to the relevant low gyromagnetic ratio and spin polarization. In this present study, a singleb value (b = 14 s/cm2) diffusion-weighted hyperpolarized129Xe MRI sequence was used to image a balloon phantom, healthy rats, and the COPD rats, respectively. All COPD rats were induced by second-hand smoke and lipopolysaccharide (LPS). The lung129XeADCmaps were obtained on a 7 T MRI scanner. The mean lung parenchymal129XeADCswere 0.044 22±0.002 9 and 0.042 34±0.002 3 cm2/s (Δ = 0.8/1.2 ms) for the COPD rats, which showed significant increasements in comparison with healthy ones (0.037 7±0.002 3 and 0.036 7±0.001 3 cm2/s). Furthermore, the correspondingADChistogram of the COPD rats exhibited a broader distribution as compared with the healthy ones. Our experiments demonstrated that the alveolar airspace enlargement in the COPD rats are able to be quantitatively evaluated by hyperpolarized xenon diffusion-weighted MRI.%超极化气体3He或者129Xe扩散加权成像已经被证明了能够有效检测慢性阻塞性肺部疾病(COPD)中肺部微结构的改变．相比于3He，129Xe更便宜而且更容易获得，但是129Xe成像中较低的信噪比致使129Xe 的肺部表面扩散系数(ADC)的测量面临着许多困难．在该研究中，为了得到更高的图像信噪比，作者对气球模型，健康大鼠和COPD大鼠进行了单个b值(14 cm2/s)的扩散加权超极化129Xe磁共振成像(MRI)．所有的COPD模型大鼠是通过烟熏和注射内毒素(LPS)进行诱导得到的．在7 T磁共振成像仪上面获得了大鼠肺实质的超极化129Xe ADC值分布图．COPD大鼠肺实质的129Xe

Review of xenon-133 production and related problems

International Nuclear Information System (INIS)

Barrachina, M.; Ropero, M.

1980-01-01

A literature survey is given on the production methods of fission xenon-133 and related problems, such as purification, metrological and dosimetric aspects, preparation of isotopic solutions, recycling, etc. 127 references are included. (Author) 127 refs

Mobility and lifetime of sup 2 sup 0 sup 8 Tl ions in liquid xenon

CERN Document Server

Walters, A J

2003-01-01

Positively charged sup 2 sup 0 sup 8 Tl ions are transported through liquid xenon using electric fields in the range of 4-10 kV cm sup - sup 1 and for drift distances up to 50 mm. From these measurements we deduce upper limits on the attenuation length for Tl ions in liquid xenon, resulting in a lifetime >5.5 s. In addition to these results, the field independent mobility of Tl bearing species in liquid xenon was measured to be 1.33+-0.04x10 sup - sup 4 cm sup 2 V sup - sup 1 s sup - sup 1. This result, when coupled with those for other species by previous workers, suggests that positive ion mobility in liquid xenon is proportional to the hard-core radius. Applications to Ba ion collection in a double beta decay experiment are also discussed.

Lowering the radioactivity of the photomultiplier tubes for the XENON1T dark matter experiment

Energy Technology Data Exchange (ETDEWEB)

Aprile, E.; Contreras, H.; Goetzke, L.W.; Fernandez, A.J.M.; Messina, M.; Plante, G.; Rizzo, A. [Columbia University, Physics Department, New York, NY (United States); Agostini, F. [INFN-Laboratori Nazionali del Gran Sasso (Italy); Gran Sasso Science Institute, L' Aquila (Italy); Bologna Univ., Department of Physics and Astrophysics, Bologna (Italy); INFN, Bologna (Italy); Alfonsi, M. [Nikhef and the University of Amsterdam, Amsterdam (Netherlands); Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Arazi, L.; Budnik, R.; Duchovni, E.; Gross, E.; Itay, R.; Landsman, H.; Lellouch, D.; Levinson, L.; Priel, N.; Vitells, O. [Weizmann Institute of Science, Department of Particle Physics and Astrophysics, Rehovot (Israel); Arisaka, K.; Lyashenko, A.; Meng, Y.; Pantic, E.; Teymourian, A.; Wang, H. [University of California, Physics and Astronomy Department, Los Angeles, CA (United States); Arneodo, F.; Di Giovanni, A. [New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Auger, M.; Barrow, P.; Baudis, L.; Behrens, A.; Galloway, M.; Kessler, G.; Kish, A.; Mayani, D.; Pakarha, P.; Piastra, F. [University of Zurich, Physik-Institut, Zurich (Switzerland); Balan, C.; Cardoso, J.M.R.; Lopes, J.A.M.; Santos, J.M.F. dos [University of Coimbra, Department of Physics, Coimbra (Portugal); Bauermeister, B.; Fattori, S.; Geis, C.; Grignon, C.; Oberlack, U.; Schindler, S. [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Beltrame, P. [Weizmann Institute of Science, Department of Particle Physics and Astrophysics, Rehovot (Israel); University of Edinburgh, Edinburgh (United Kingdom); Brown, A.; Lang, R.F.; Macmullin, S.; Pienaar, J.; Reichard, S.; Reuter, C. [Purdue University, Department of Physics and Astronomy, West Lafayette, IN (United States); Brown, E.; Levy, C. [Rensselaer Polytechnic Institute, Department of Physics, Applied Physics and Astronomy, Troy, NY (United States); Wilhelms-Universitaet Muenster, Institut fuer Kernphysik, Muenster (Germany); Bruenner, S.; Hampel, W.; Kaether, F.; Lindemann, S.; Lindner, M.; Undagoitia, T.M.; Rauch, L.; Schreiner, J.; Simgen, H.; Weber, M. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Bruno, G. [INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, L' Aquila (Italy); Wilhelms-Universitaet Muenster, Institut fuer Kernphysik, Muenster (Germany); Buetikofer, L.; Coderre, D.; Schumann, M. [University of Bern, Albert Einstein Center for Fundamental Physics, Bern (Switzerland); Colijn, A.P.; Decowski, M.P.; Tiseni, A.; Tunnell, C. [Nikhef and the University of Amsterdam, Amsterdam (Netherlands); Cussonneau, J.P.; Le Calloch, M.; Masbou, J.; Lavina, L.S.; Thers, D. [Universite de Nantes, Subatech, Ecole des Mines de Nantes, CNRS/In2p3, Nantes (France); Ferella, A.D.; Fulgione, W.; Laubenstein, M. [INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, L' Aquila (Italy); Fieguth, A.; Murra, M.; Rosendahl, S.; Weinheimer, C. [Wilhelms-Universitaet Muenster, Institut fuer Kernphysik, Muenster (Germany); Garbini, M.; Massoli, F.V.; Sartorelli, G.; Selvi, M. [Bologna Univ., Department of Physics and Astrophysics, Bologna (Italy); INFN, Bologna (Italy); Miguez, B.; Molinario, A.; Trinchero, G. [INFN-Torino and Osservatorio Astrofisico di Torino, Turin (Italy); Naganoma, J.; Shagin, P.; Wall, R. [Rice University, Department of Physics and Astronomy, Houston, TX (United States); Orrigo, S.E.A. [University of Coimbra, Department of Physics, Coimbra (Portugal); IFIC, CSIC-Universidad de Valencia, Valencia (Spain); Persiani, R. [Universite de Nantes, Subatech, Ecole des Mines de Nantes, CNRS/In2p3, Nantes (FR); Bologna Univ., Department of Physics and Astrophysics, Bologna (IT); INFN, Bologna (IT); Collaboration: XENON Collaboration

2015-11-15

The low-background, VUV-sensitive 3-inch diameter photomultiplier tube R11410 has been developed by Hamamatsu for dark matter direct detection experiments using liquid xenon as the target material. We present the results from the joint effort between the XENON collaboration and the Hamamatsu company to produce a highly radio-pure photosensor (version R11410-21) for the XENON1T dark matter experiment. After introducing the photosensor and its components, we show the methods and results of the radioactive contamination measurements of the individual materials employed in the photomultiplier production. We then discuss the adopted strategies to reduce the radioactivity of the various PMT versions. Finally, we detail the results from screening 286 tubes with ultra-low background germanium detectors, as well as their implications for the expected electronic and nuclear recoil background of the XENON1T experiment. (orig.)

46 CFR 45.129 - Hull fittings: General.

Science.gov (United States)

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Hull fittings: General. 45.129 Section 45.129 Shipping... Assignment § 45.129 Hull fittings: General. Hull fittings must be securely mounted in the hull so as to avoid increases in hull stresses and must be protected from local damage caused by movement of equipment or cargo. ...

Contribution to the study of nuclear fuel materials with a metallic uranium base; Contribution a l'etude des materiaux combustibles nucleaires a base d'uranium metallique

Energy Technology Data Exchange (ETDEWEB)

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

1957-11-15

In a power reactor destined to supply industrially recoverable thermal energy, the most economical source of heat still consists of natural metallic uranium. However, the nuclear fuel material, most often employed in the form of rods of 20 to 40 mm diameter, is subjected to a series of stresses which lead to irreversible distortions usually incompatible with the substructure of the reactor. As a result the fuel material must possess at the outset a certain number of qualities which must be determined. Investigations have therefore been carried out, first on the technological characters peculiar to each of the three allotropic phases of pure uranium metal, and on their interactions on the stabilisation of the material which consists of either cast uranium or uranium pile-treated in the {gamma} phase. (author) [French] Dans un reacteur de puissance destine a fournir de l'energie thermique industriellement recuperable, la source de chaleur la plus economique reste constituee par de l'uranium metallique naturel. Or, le materiau combustible nucleaire, employe le plus souvent sous forme de barreaux de 20 a 40 mm de diametre, se trouve soumis a un ensemble de contraintes qui provoque des deformations irreversibles, le plus souvent incompatibles avec l'infrastructure du reacteur. Par consequent, le materiau combustible doit presenter a l'origine un certain nombre de qualites qu'il est necessaire de determiner. Aussi a-t-on d'abord etudie les caracteres technologiques propres a chacune des trois phases allotropiques de l'uranium-metal pur et leurs interactions sur la stabilisation du materiau constitue soit par de l'uranium coule, soit par de l'uranium traite en pile en phase {gamma}. (auteur)

Iodine-129 in thyroids of grazing animals

International Nuclear Information System (INIS)

Ballad, R.V.; Holman, D.W.; Hennecke, E.W.; Johnson, J.E.; Manuel, O.K.; Nicholson, L.M.

1976-01-01

A combination of neutron activation and mass spectrometry has been used to determine the concentrations of fissiogenic 129 I and stable 127 I in thyroids of grazing animals and in mineral iodine. The 129 I/ 127 I ratios are lowest in mineral iodine and in a given area lower in cow thyroids than in deer thyroids. Near saturation levels of mineral iodine in commercial feeds and salt licks may account for differences in the 129 I levels of cows and deer. Values of the 129 I/ 127 I ratio in deer appear to vary inversely with the iodine concentration of the thyroid. (author)

Development of a liquid xenon Compton telescope dedicated to functional medical imaging; Etude et developpement d'un telescope compton au xenon liquide dedie a l'imagerie medicale fonctionnelle

Energy Technology Data Exchange (ETDEWEB)

Grignon, C

2007-12-15

Functional imaging is a technique used to locate in three dimensions the position of a radiotracer previously injected in a patient. The two main modalities used for a clinical application to detect tumors, the SPECT and the PET, use solid scintillators as a detection medium. The objective of this thesis was to investigate the possibility of using liquid xenon in order to benefit from the intrinsic properties of this medium in functional imaging. The feasibility study of such a device has been performed by taking into account the technical difficulties specific to the liquid xenon. First of all, simulations of a liquid xenon PET has been performed using Monte-Carlo methods. The results obtained with a large liquid xenon volume are promising : we can expect a reduction of the injected activity of radiotracer, an improvement of the spatial resolution of the image and a parallax free camera. The second part of the thesis was focused on the development of a new concept of medical imaging, the three gamma imaging, based on the use of a new emitter: the 44 scandium. Associated to a classical PET camera, the Compton telescope is used to infer the incoming direction of the third gamma ray by triangulation. Therefore, it is possible to reconstruct the position of each emitter in three dimensions. This work convinced the scientific community to support the construction and characterization of a liquid xenon Compton telescope. The first camera dedicated to small animal imaging should then be operational in 2009. (author)

Collateral ventilation to congenital hyperlucent lung lesions assessed on xenon-enhanced dynamic dual-energy CT: an initial experience.

Science.gov (United States)

Goo, Hyun Woo; Yang, Dong Hyun; Kim, Namkug; Park, Seung Il; Kim, Dong Kwan; Kim, Ellen Ai-Rhan

2011-01-01

We wanted to evaluate the resistance to collateral ventilation in congenital hyperlucent lung lesions and to correlate that with the anatomic findings on xenon-enhanced dynamic dual-energy CT. Xenon-enhanced dynamic dual-energy CT was successfully and safely performed in eight children (median age: 5.5 years, 4 boys and 4 girls) with congenital hyperlucent lung lesions. Functional assessment of the lung lesions on the xenon map was done, including performing a time-xenon value curve analysis and assessing the amplitude of xenon enhancement (A) value, the rate of xenon enhancement (K) value and the time of arrival value. Based on the A value, the lung lesions were categorized into high or low (A value > 10 Hounsfield unit [HU]) resistance to collateral ventilation. In addition, the morphologic CT findings of the lung lesions, including cyst, mucocele and an accessory or incomplete fissure, were assessed on the weighted-average CT images. The xenon-enhanced CT radiation dose was estimated. Five of the eight lung lesions were categorized into the high resistance group and three lesions were categorized into the low resistance group. The A and K values in the normal lung were higher than those in the low resistance group. The time of arrival values were delayed in the low resistance group. Cysts were identified in five lesions, mucocele in four, accessory fissure in three and incomplete fissure in two. Either cyst or an accessory fissure was seen in four of the five lesions showing high resistance to collateral ventilation. The xenon-enhanced CT radiation dose was 2.3 ± 0.6 mSv. Xenon-enhanced dynamic dual-energy CT can help visualize and quantitate various degrees of collateral ventilation to congenital hyperlucent lung lesions in addition to assessing the anatomic details of the lung.

Effects of temperature and irradiation on the mobility of Xenon in UO2: Profilometric and microstructural study

International Nuclear Information System (INIS)

Marchand, B.

2012-01-01

In France, electricity is mainly produced (78%) through the operation of 58 PWRs (Pressurized Water Reactors). During reactor operation, many fission products (FP) are generated in the fuel which is, in most cases, UO 2 enriched to about 4% in 235 U. Among FPs, gaseous fission products as Xenon and Krypton, are abundantly produced (around 15% stable fission products). Because of their chemical nature, those two gases have a very low solubility in the fuel and therefore tend to form bubbles (to minimize surface tension) and can cause pellets swelling. The formed gas can also be released out of the pellet, and lead to a substantial increase in the pressure within the fuel cladding, thereby limiting the energy production. However, migration mechanisms, traditionally studied indirectly by measuring the amount of gas released after irradiation, are not yet fully understood. It is frequently assumed that atomic diffusion is the only mechanism that can lead to a migration of xenon. The objective of this thesis is to provide direct evidence of the different mechanisms controlling the behavior of Xenon during thermal annealing and irradiation. Therefore, we used ion implantation to introduce Xenon in uranium dioxide samples. After implantation, the Xenon distribution follows a quasi-Gaussian concentration profile (variation of the concentration regard to the depth) located in the first 300 nanometers of the sample. We have performed post-implantation annealing at 1400 C and 1600 C in order to study the impact of the temperature, and irradiation with ions to simulate the impact of fission products in the fuel. Subsequently, concentration depth profiles were measured by ion microprobe (SIMS). Although the feasibility of Xenon measurement has been demonstrated in several articles, no concentration profile had so far been presented in the literature because a classical data processing of SIMS data is not suitable in uranium dioxide. Therefore a new data processing software has

Calculation of xenon-oscillations in the HPLWR

International Nuclear Information System (INIS)

Reiss, T.; Feher, S.; Czifrus, Sz.

2009-01-01

The European version of the Supercritical Water Cooled Reactor (SCWR) is being developed under the name High Performance Light Water Reactor (HPLWR). In the most recent design, a three-pass core is foreseen with a heat-up of the coolant (supercritical pressure water) from 280degC to 500degC. Due to the operating pressure of 25 MPa, there is no phase change in the core but the density drop of the coolant can be as high as one order of magnitude. This results in a system which is sensitive to local temperature, power and density oscillations. This attribute is enhanced by the pseudocritical transformation of supercritical pressure water. Due to the relatively large dimensions of the core, xenon-oscillations are probable. The characteristic time of this process is several hours, thus a coupled quasi-stationary neutronics-thermohydraulics (CQNT) code completed with the xenon poisoning differential equations (XPDE) can predict the extent of xenon-oscillations. A program system is being developed at the Budapest University of Technology which is capable to perform full core CQNT calculations including the XPDE. The program system is designed to calculate one-pass (which was the first core proposal for HPLWRs, today called PWR-SC) and three-pass cores. The CQNT code is made up of an MCNP part (neutronics part) and of a thermohydraulics part developed at our Institute. Since full core MCNP calculations are very time consuming, upon symmetry considerations only one eighth of the core is modelled. On the other hand, this approach of modelling momentarily limits the phenomena which can be studied to axial oscillations. (author)

Preparation and study of the properties of lead telluride and cadmium telluride diodes for use in nuclear spectrometry; Preparation et etude des proprietes de diodes au tellurure de plomb et au tellurure de cadmium en vue d'une utilisation en spectrometrie nucleaire

Energy Technology Data Exchange (ETDEWEB)

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

1969-07-01

This work studies the possibility of using high atomic number compound semiconductors, like lead telluride and cadmium telluride as to realize nuclear radiation detectors, specially in gamma ray spectrometry because of their high absorption coefficient. The problems related to the preparation of binary compounds are exposed. Experiments on PbTe show the influence of the conditions of preparation on the electrical properties of the semiconductor which are greatly dependent on the stoichiometry of the compound. PbTe surface-barrier diodes were realized and have been used to study the surface properties of this semiconductor. These diodes cannot detect nuclear radiations because of the too weak resistivity of our material. Different types of devices made of Cd Te have been studied. One of these diodes has been used as an alpha particle detector. We explain the relative poor performances of that detector by the presence of lattice defects in Cd Te where charge carriers may recombine themselves. By analysing the properties of gold diffused Cd Te diodes we identified this defect, the cadmium vacancy, the presence of which is due to the deviation from stoichiometry during the preparation of the material. (author) [French] Ce travail etudie la possibilite d'utiliser des semiconducteurs composes d'elements a numero atomique eleve, tels que le tellurure de plomb et le tellurure de cadmium pour la realisation de detecteurs de rayonnements nucleaires, grace notamment a la section efficace de capture elevee qu'ils presentent vis-a-vis des rayons gamma. On souligne les problemes relatifs a la preparation des composes binaires. Les experiences realisees sur PbTe mettent en evidence l'influence des conditions de preparation sur les proprietes electriques du semiconducteur qui dependent fortement de la stoechiometrie du compose. Nous avons realise des diodes au PbTe a barriere de surface qui ont permis de preciser les proprietes de surface de ce semiconducteur. La trop faible

The control of the radioactive pollution of milk (1962); Comment concevoir une surveillance des pollutions radioactives du lait (1962)

Energy Technology Data Exchange (ETDEWEB)

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

1962-07-01

Milk, an essential foodstuff, is the object of a supervision and vigilant controls governed by numerous laws which protect its commercial and sanitary qualities. The development of the use of nuclear energy poses and will pose new problems of hygiene and the milk should benefit from controls concerning its possible contamination. Grass-eating animals are particularly subjected to radioactive contaminations and the milk which they produce does not escape contamination because of of its saline composition and of the particular metabolism of the mammary gland. As a result, milk is a contamination integrator and its analysis makes it possible to detect radioelements which can only be detected with great difficulty in an average size plant sample. (author) [French] Le lait, aliment essentiel, fait l'objet d'une surveillance et de controles vigilants regis par de nombreux textes legislatifs qui protegent ses qualites marchandes et sanitaires. Le developpement de l'utilisation de l'energie nucleaire pose et posera de nouveaux problemes d'hygiene et le lait doit beneficier de controles portant sur sa pollution radioactive eventuelle. Les, animaux herbivores sont particulierement exposes aux contaminations radioactives et les laits qu'ils produisent, du fait de leurs compositions salines et du metabolisme particulier de la glande mammaire, n'echappent point aux pollutions. De ce fait, le lait est un integrateur de contamination et son analyse permet de retrouver des radioelements que l'on ne decele qu'avec beaucoup de difficultes sur un echantillon vegetal de taille moyenne. (auteur)

The 129-iodine content of subtropical Pacific waters. Impact of Fukushima and other anthropogenic 129-iodine sources

Energy Technology Data Exchange (ETDEWEB)

Guilderson, T.P. [Lawrence Livermore National Laboratory, Livermore, CA (United States). Center for Accelerator Mass Spectrometry; California Univ., Santa Cruz, CA (United States). Dept. of Ocean Sciences and Inst. of Marine Sciences; Tumey, S.J.; Brown, T.A. [Lawrence Livermore National Laboratory, Livermore, CA (United States). Center for Accelerator Mass Spectrometry; Buesseler, K.O. [Woods Hole Oceanographic Institution, Woods Hole, MA (United States). Dept. of Marine Chemistry and Geochemistry

2014-07-01

Results obtained from a dedicated radiochemistry cruise approximately 100 days after the 11 March 2011 Tohoku earthquake and subsequent disaster at the Fukushima Daiichi Nuclear Power Plant show that Fukushima derived radionuclides in the nearby ocean environment had penetrated, on average, to ≤250 m depth (1026.5 kg m{sup 3} potential density surface). The excess inventory of Fukushima-derived {sup 129}I in the region (∝150 000 km{sup 2}) sampled during the cruise is estimated to have been between 0.89 and 1.173 billion Bq (∝136 to ∝179 grams) of {sup 129}I. Based on a tight tracer-tracer relation with {sup 134}Cs (or {sup 137}Cs) and estimates that most of the excess cesium is due to direct discharge, we infer that much of the excess {sup 129}I is from direct (non-atmospheric deposition) discharge. After taking into account oceanic transport, we estimate the direct discharge, i.e., that directly released into the ocean, off Fukushima to have been ∝1 kg {sup 129}I. Although this small pulse is dwarfed by the ∝90 kg of weapons-testing-derived {sup 129}I that was released into the environment in the late 1950s and early 1960s, it should be possible to use Fukushima-derived {sup 129}I and other radionuclides (e.g., {sup 134,} {sup 137}Cs) to study transport and entrainment processes along and across the Kuroshio Current.

Speciation and migration of 129I in soil profiles

International Nuclear Information System (INIS)

Luo, Maoyi; Hou, Xiaolin; Zhou, Weijian; He, Chaohui; Chen, Ning; Liu, Qi; Zhang, Luoyuan

2013-01-01

A method has been developed for speciation analysis of ultra low level 129 I in soil using sequential extraction combined with coprecipitation for separation of carrier free iodine and AMS measurement of 129 I. Two loess profiles collected from northwest China were analyzed for species of 129 I and 127 I. Similar partitioning of 129 I and 127 I was observed in the loess profiles, the distribution of iodine isotopes followed an order of organic > leachable > reducible > residue. The 129 I concentrations and 129 I/ 127 I ratios decreased exponentially with the depth, and 2 orders of magnitude lower in the deepest layer (60 and 90 cm) compared with the top layer, indicating a significant contribution of anthropogenic input in the upper layer, and high retention of 129 I in soil. The mobility of 129 I in different fractions decreased in an order of leachable > organic > oxides > residue. The results suggest that migration of iodine downwards in the soil profile is a slow process; the oxides and residue are the less mobile fractions of iodine. Highlights: ► 129 I concentration decreases exponentially with the depth of soil profile. ► The mobility of 129 I in fractions decreases: leachable > organic > oxides > residue. ► Iodine shows less mobility in oxides and residue fractions. ► High organic soil content can effectively reduce the migration of 129 I in the environment. ► Carrier free iodine AMS is an effective method for natural 129 I speciation analysis in the environment

Dicty_cDB: SSK129 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available SS (Link to library) SSK129 (Link to dictyBase) - - - Contig-U16021-1 SSK129Z (Link... to Original site) - - SSK129Z 372 - - - - Show SSK129 Library SS (Link to library) Clone ID SSK129 (Link to dict...yBase) Atlas ID - NBRP ID - dictyBase ID - Link to Contig Contig-U16021-1 Original site URL http://dict...Homology vs DNA Score E Sequences producing significant alignments: (bits) Value N AC116957 |AC116957.2 Dict...419632 |CK419632.1 AUF_IpOva_21_i24 Ovary cDNA library Ictalurus punctatus cDNA 5', mRNA sequence. 36 0.54 2

Depth distribution of martensite in xenon implanted stainless steels

International Nuclear Information System (INIS)

Johansen, A.; Johnson, E.; Sarholt-Kristensen, L.; Steenstrup, S.; Hayashi, N.; Sakamoto, I.

1989-01-01

The amount of stress-induced martensite and its distribution in depth in xenon implanted austenitic stainless steel poly- and single crystals have been measured by Rutherford backscattering and channeling analysis, depth selective conversion electron Moessbauer spectroscopy, cross-sectional transmission electron microscopy and x-ray diffraction analysis. In low nickel 17/7, 304 and 316 commercial stainless steels and in 17:13 single crystals the martensitic transformation starts at the surface and develops towards greater depth with increasing xenon fluence. The implanted layer is nearly completely transformed, and the interface between martensite and austenite is rather sharp and well defined. In high nickel 310 commercial stainless steel and 15:19 and 20:19 single crystals, on the other hand, only insignificant amounts of martensite are observed. (orig.)

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

Energy Technology Data Exchange (ETDEWEB)

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

Two-group Analysis of Xenon Stability in Slab Geometry by Modal Expansion

International Nuclear Information System (INIS)

Norinder, O.

1963-05-01

Xenon spatial stability is analyzed with the flux represented by two neutron energy groups. General formulas are given for expansions in a system of modes. Detailed formulas are recorded for a slab described by sinusoidal modes. A short description is given of a Mercury Autocode program for numerical calculations in slab geometry. The essential input parameters and results are noted for 80 computed cases. The main body of the calculations were intended to clarify the xenon stability properties of the Marviken reactor, which was found to have a sufficient margin against unstable xenon oscillations. The neutron flux detection and the control rod insertion in the slab were found to have a large influence on the stability in spite of the nonexistence of space-selective control in the systems investigated. Very good agreement was found between stability limits calculated according to Randall and St. John and stability limits calculated by the program

Two-group Analysis of Xenon Stability in Slab Geometry by Modal Expansion

Energy Technology Data Exchange (ETDEWEB)

Norinder, O

1963-05-15

Xenon spatial stability is analyzed with the flux represented by two neutron energy groups. General formulas are given for expansions in a system of modes. Detailed formulas are recorded for a slab described by sinusoidal modes. A short description is given of a Mercury Autocode program for numerical calculations in slab geometry. The essential input parameters and results are noted for 80 computed cases. The main body of the calculations were intended to clarify the xenon stability properties of the Marviken reactor, which was found to have a sufficient margin against unstable xenon oscillations. The neutron flux detection and the control rod insertion in the slab were found to have a large influence on the stability in spite of the nonexistence of space-selective control in the systems investigated. Very good agreement was found between stability limits calculated according to Randall and St. John and stability limits calculated by the program.

Phase behavior of mixed submonolayer films of krypton and xenon on graphite.

Science.gov (United States)

Patrykiejew, A; Sokołowski, S

2012-04-14

Using the results of extensive Monte Carlo simulations in the canonical and grand canonical ensembles, we discuss the phase behavior of mixed submonolayer films of krypton and xenon adsorbed on the graphite basal plane. The calculations have been performed using two- and three-dimensional models of the systems studied. It has been demonstrated that out-of-plane motion does not affect the properties of the films as long as the total density is well below the monolayer completion and at moderate temperatures. For the total densities close to the monolayer completion, the promotion of particles to the second layer considerably affects the film properties. Our results are in a reasonable agreement with the available experimental data. The melting point of submonolayer films has been shown to exhibit non-monotonous changes with the film composition, and reaches minimum for the xenon concentration of about 50%. At the temperatures below the melting point, the structure of solid phases depends upon the film composition and the temperature; one can also distinguish commensurate and incommensurate phases. Two-dimensional calculations have demonstrated that for the xenon concentration between about 15% and 65% the adsorbed film exhibits the formation of a superstructure, in which each Xe atom is surrounded by six Kr atoms. This superstructure is stable only at very low temperatures and transforms into the mixed commensurate (√3×√3)R30° phase upon the increase of temperature. Such a superstructure does not appear when a three-dimensional model is used. Grand canonical ensemble calculations allowed us to show that for the xenon concentration of about 3% the phase diagram topology of monolayer films changes from the krypton-like (with incipient triple point) to the xenon-like (with ordinary triple point).

Actes des 5èmes Journées Scientifiques du GDR3544 Sciences du Bois. Journées Annuelles du GDR 3544 Sciences du Bois

OpenAIRE

CHAPLAIN, Myriam; CARE, Sabine; GRIL, Joseph

2016-01-01

Le Groupement de Recherche en Sciences du bois (GDR3544 Sciences du Bois) a été créé en 2012 par le CNRS et renouvelé en 2016 pour 5 ans. La mission de ce groupement est : (1) de structurer la recherche sur le bois en France pour lui donner une visibilité nationale, (2) de contribuer au développement de la formation en sciences du bois et (3) de servir de relai aux réseaux internationaux de sciences du bois. Les 5èmes journées annuelles du GDR Bois ont été organisées à Bordeaux, au domaine du...

Lowering the radioactivity of the photomultiplier tubes for the XENON1T dark matter experiment

NARCIS (Netherlands)

Aprile, E.; et al., [Unknown; Alfonsi, M.; Colijn, A.P.; Decowski, M.P.; Tiseni, A.; Tunnell, C.

2015-01-01

The low-background, VUV-sensitive 3-inch diameter photomultiplier tube R11410 has been developed by Hamamatsu for dark matter direct detection experiments using liquid xenon as the target material. We present the results from the joint effort between the XENON collaboration and the Hamamatsu company

Experimental development of a liquid xenon Compton telescope for functional medical imaging

International Nuclear Information System (INIS)

Oger, Tugdual

2012-01-01

3γ imaging is a new nuclear medical imaging technique which has been suggested by Subatech laboratory. This technique involves locating three-dimensional position of the decay of an innovative radioisotope (β + ,γ) emitter, the 44 Sc. The principle consist in the detection of two photons of 511 keV gamma rays from the decay of the positron, provided by a PET ring detector, associated to the detection of the third photon by a Liquid xenon Compton telescope. The energy deposited in the interaction between the photon and xenon and its position are identified by measuring the ionization signal with a Micromegas chamber (Micro-Mesh Gaseous Structure), while the trigger and time measurement of the interaction are provided by the detection of the scintillation signal. The principle of the TPC is thus used to Compton imaging. In order to demonstrate experimentally the feasibility of imaging 3γ, a small prototype, XEMIS (Xenon Medical Imaging System) was developed. This thesis is an important step towards the proof of feasibility. In this work are exposed the characterization of the detector response for a beam of 511 keV gamma rays and the analysis of data derived from it. The measurement of energy and time resolutions will be presented, as well as the purity of the liquid xenon. (author) [fr

Nausea and Vomiting following Balanced Xenon Anesthesia Compared to Sevoflurane: A Post-Hoc Explorative Analysis of a Randomized Controlled Trial.

Directory of Open Access Journals (Sweden)

Astrid V Fahlenkamp

Full Text Available Like other inhalational anesthetics xenon seems to be associated with post-operative nausea and vomiting (PONV. We assessed nausea incidence following balanced xenon anesthesia compared to sevoflurane, and dexamethasone for its prophylaxis in a randomized controlled trial with post-hoc explorative analysis.220 subjects with elevated PONV risk (Apfel score ≥2 undergoing elective abdominal surgery were randomized to receive xenon or sevoflurane anesthesia and dexamethasone or placebo after written informed consent. 93 subjects in the xenon group and 94 subjects in the sevoflurane group completed the trial. General anesthesia was maintained with 60% xenon or 2.0% sevoflurane. Dexamethasone 4mg or placebo was administered in the first hour. Subjects were analyzed for nausea and vomiting in predefined intervals during a 24h post-anesthesia follow-up.Logistic regression, controlled for dexamethasone and anesthesia/dexamethasone interaction, showed a significant risk to develop nausea following xenon anesthesia (OR 2.30, 95% CI 1.02-5.19, p = 0.044. Early-onset nausea incidence was 46% after xenon and 35% after sevoflurane anesthesia (p = 0.138. After xenon, nausea occurred significantly earlier (p = 0.014, was more frequent and rated worse in the beginning. Dexamethasone did not markedly reduce nausea occurrence in both groups. Late-onset nausea showed no considerable difference between the groups.In our study setting, xenon anesthesia was associated with an elevated risk to develop nausea in sensitive subjects. Dexamethasone 4mg was not effective preventing nausea in our study. Group size or dosage might have been too small, and change of statistical analysis parameters in the post-hoc evaluation might have further contributed to a limitation of our results. Further trials will be needed to address prophylaxis of xenon-induced nausea.EU Clinical Trials EudraCT-2008-004132-20 ClinicalTrials.gov NCT00793663.

Investigation of the radioecology of iodine 129

International Nuclear Information System (INIS)

Schuettelkopf, H.

1979-01-01

Very sensitive analytical methods for I-129 were developed for different sample materials. - The behaviour of I-129 in the Karlsruhe reprocessing plant and its release was completely investigated. - A longterm risk for the population caused by I-129 is not excpected. An existing environmental contamination with I-129 is reduced by a half-life of 0,3 y. The exposure of the population via the pasture-cow-milk path until now was overstimated at least by a factor 45. - In the environmental air of Kiel, Stade, Karlsruhe, Gundremmingen and Munich elemental iodine and iodine aerosols were measured. In the environmental air of Karlsruhe CH 3 127 I was determined. (orig./RW) [de

Delayed xenon post-conditioning mitigates spinal cord ischemia/reperfusion injury in rabbits by regulating microglial activation and inflammatory factors.

Science.gov (United States)

Yang, Yan-Wei; Wang, Yun-Lu; Lu, Jia-Kai; Tian, Lei; Jin, Mu; Cheng, Wei-Ping

2018-03-01

The neuroprotective effect against spinal cord ischemia/reperfusion injury in rats exerted by delayed xenon post-conditioning is stronger than that produced by immediate xenon post-conditioning. However, the mechanisms underlying this process remain unclear. Activated microglia are the main inflammatory cell type in the nervous system. The release of pro-inflammatory factors following microglial activation can lead to spinal cord damage, and inhibition of microglial activation can relieve spinal cord ischemia/reperfusion injury. To investigate how xenon regulates microglial activation and the release of inflammatory factors, a rabbit model of spinal cord ischemia/reperfusion injury was induced by balloon occlusion of the infrarenal aorta. After establishment of the model, two interventions were given: (1) immediate xenon post-conditioning-after reperfusion, inhalation of 50% xenon for 1 hour, 50% N 2 /50%O 2 for 2 hours; (2) delayed xenon post-conditioning-after reperfusion, inhalation of 50% N 2 /50%O 2 for 2 hours, 50% xenon for 1 hour. At 4, 8, 24, 48 and 72 hours after reperfusion, hindlimb locomotor function was scored using the Jacobs locomotor scale. At 72 hours after reperfusion, interleukin 6 and interleukin 10 levels in the spinal cord of each group were measured using western blot assays. Iba1 levels were determined using immunohistochemistry and a western blot assay. The number of normal neurons at the injury site was quantified using hematoxylin-eosin staining. At 72 hours after reperfusion, delayed xenon post-conditioning remarkably enhanced hindlimb motor function, increased the number of normal neurons at the injury site, decreased Iba1 levels, and inhibited interleukin-6 and interleukin-10 levels in the spinal cord. Immediate xenon post-conditioning did not noticeably affect the above-mentioned indexes. These findings indicate that delayed xenon post-conditioning after spinal cord injury improves the recovery of neurological function by reducing

Effets de la microdose sur la production du niébé, du mil et du ...

African Journals Online (AJOL)

Effets de la microdose sur la production du niébé, du mil et du sorgho en fonction la toposéquence. Fatimata Saba, Sibiri Jean Baptiste Taonda, Idriss Serme, Alimata A. Bandaogo, Augustin P. Sourwema, Adama Kabre ...

Gas purity analytics, calibration studies, and background predictions towards the first results of XENON1T

Energy Technology Data Exchange (ETDEWEB)

Hasterok, Constanze

2017-10-25

The XENON1T experiment aims at the direct detection of the well motivated dark matter candidate of weakly interacting massive particles (WIMPs) scattering off xenon nuclei. The first science run of 34.2 live days has already achieved the most stringent upper limit on spin-independent WIMP-nucleon cross-sections above masses of 10 GeV with a minimum of 7.7.10{sup -47} cm{sup 2} at a mass of 35 GeV. Crucial for this unprecedented sensitivity are a high xenon gas purity and a good understanding of the background. In this work, a procedure is described that was developed to measure the purity of the experiment's xenon inventory of more than three tons during its initial transfer to the detector gas system. The technique of gas chromatography has been employed to analyze the noble gas for impurities with the focus on oxygen and krypton contaminations. Furthermore, studies on the calibration of the experiment's dominating background induced by natural gamma and beta radiation were performed. Hereby, the novel sources of radioactive isotopes that can be dissolved in the xenon were employed, namely {sup 220}Rn and tritium. The sources were analyzed in terms of a potential impact on the outcome of a dark matter search. As a result of the promising findings for {sup 220}Rn, the source was successfully deployed in the first science run of XENON1T. The first WIMP search of XENON1T is outlined in this thesis, in which a background component from interactions taking place in close proximity to the detector wall is identified, investigated and modeled. A background prediction was derived that was incorporated into the background model of the WIMP search which was found to be in good agreement with the observation.

The Shaker Potassium Channel Is No Target for Xenon Anesthesia in Short-Sleeping Drosophila melanogaster Mutants

Directory of Open Access Journals (Sweden)

C. Schaper

2012-01-01

Full Text Available Background. Xenon seems to be an ideal anesthetic drug. To explore if next to the antagonism at the NMDA-receptor other molecular targets are involved, we tested the xenon requirement in short sleeping Drosophila shaker mutants and in [ℎ38]. Methods. The Drosophila melanogaster strains wildtype Canton-S, [ℎ38], ℎ102 and ℎ, were raised and sleep was measured. Based on the response of the flies at different xenon concentrations, logEC50 values were calculated. Results. The logEC50-values for WT Canton-S were 1.671 (1.601–1.742 95%-confidence intervall; =238; P versus ℎ102 > 0,05, for ℎ 1.711 (1.650–1.773; =242; P versus WT Canton-S > 0,05. The logEC50-value for ℎ102 was 1.594 (1.493–1.694; =261; P versus ℎ > 0.05. The logEC-value of [ℎ38] was 2.076 (1.619–2.532; =207; P versus ℎ 0.05, while [ℎ38] was found to be hyposensitive compared to wildtype (P < 0.05. Conclusions. The xenon requirement in Drosophila melanogaster is not influenced by a single gene mutation at the shaker locus, whereas a reduced expression of a nonselective cation channel leads to an increased xenon requirement. This supports the thesis that xenon mediates its effects not only via an antagonism at the NMDA-receptor.

Preliminary investigation of actinide and xenon reactivity effects in accelerator transmutation of waste high-flux systems

International Nuclear Information System (INIS)

Olson, K.R.; Henderson, D.L.

1995-01-01

The possibility of an unstable positive reactivity growth in an accelerator transmutation of waste (ATW)-type high-flux system is investigated. While it has always been clear that xenon is an important actor in the reactivity response of a system to flux changes, it has been suggested that in very high thermal flux transuranic burning systems, a positive, unstable reactivity growth could be caused by the actinides alone. Initial system reactivity response to flux changes caused by the actinides and xenon are investigated separately. The maximum change in reactivity after a flux change caused by the effect of the changing quantities of actinides is generally at least two orders of magnitude smaller than either the positive or negative reactivity effect associated with xenon after a shutdown or startup. In any transient flux event, the reactivity response of the system to xenon will generally occlude the response caused by the actinides. The capabilities and applications of both the current actinide model and the xenon model are discussed. Finally, the need for a complete dynamic model for the high-flux fluid-fueled ATW system is addressed

Technical and Economic Problems Associated with the Development of Methods of Processing and Using Radioactive Waste; Problemes techniques et economiques lies au developpement des methodes de traitement et d'utilisation des dechets radioactifs

Energy Technology Data Exchange (ETDEWEB)

Thiriet, L; Sauteron, J; Oger, C [Commissariat a l' Energie Atomique, Fontenay-Aux-Roses (France). Centre d' Etudes Nucleaires

1968-07-01

The paper briefly reviews the various techniques used in processing the radioactive wastes which unavoidably result from the generation of electric power from nuclear sources. The paper goes on to define the relative importance, in nuclear fuel cycles, of the problem raised by these wastes. Emphasis is placed on the economic influence of management policies on the cost of power generation, and hence on the relative position of nuclear energy. A substantial percentage of these wastes can be economically utilized. Attention is drawn to the major technical and economic features of the industry which will come into being as a result of this utilization. The major uses anticipated are discussed: radiation sources, heat sources, auxiliary power generation. The paper concludes that satisfactory solutions have already been found to these problems, and describes possible improvements. (author) [French] La communication rappelle d'abord succinctement les differentes techniques de traitement des dechets radioactifs resultant necessairement de la production d'electricite d'origine nucleaire. On situe ensuite l'importance du probleme pose par ces residus dans le cycle du combustible nucleaire. On fait ressortir l'influence economique du choix des methodes de gestion sur le cout de production de l'energie, et par consequent sur la place devolue a l'energie nucleaire. Une part importante de ces dechets peut faire l'objet d'une utilisation rentable de l'industrie qui naitra de cette utilisation. Les principales applications envisagees sont evoquees: sources d'irradiation, sources chauffantes, generateurs auxiliaires d'energie. On conclut que d'ores et deja des solutions satisfaisantes ont ete apportees a ces problemes, et l'on decrit les perspectives d'amelioration concevables. (auteur)

10 CFR 1.29 - Office of International Programs.

Science.gov (United States)

2010-01-01

... maintains working relationships with individual countries and international nuclear organizations, as well... 10 Energy 1 2010-01-01 2010-01-01 false Office of International Programs. 1.29 Section 1.29 Energy... Staff § 1.29 Office of International Programs. The Office of International Programs— (a) Advises the...

14 CFR 129.28 - Flightdeck security.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Flightdeck security. 129.28 Section 129.28... Flightdeck security. (a) After August 20, 2002, except for a newly manufactured airplane on a non-revenue...; or the operator must implement a security program approved by the Transportation Security...

L'administration du travail et la production du droit du travail (1906-1960). : Note de synthèse du rapport de recherche

OpenAIRE

Le Crom , Jean-Pierre

2007-01-01

Synthèse d'un rapport de recherche dont l'objectif est d'appréhender le rôle de l'administration centrale du travail dans la production du droit du travail. Deux dimensions sont explorées : le profil des rédacteurs et l'organisation des structures.

Studies on adsorption-desorption of xenon on surface of BC-404 plastic scintillator based on soaking method

Energy Technology Data Exchange (ETDEWEB)

Yongchun, Xiang [Institute of Nuclear Physics and Chemistry, China and Academy of Engineer Physics, Mianyang 621900 (China); School of Physics, Peking University, Beijing 100080 (China); Tieshuan, Fan [School of Physics, Peking University, Beijing 100080 (China); Chuanfei, Zhang; Fei, Luo; Qian, Wang; Rende, Ze [Institute of Nuclear Physics and Chemistry, China and Academy of Engineer Physics, Mianyang 621900 (China); Qingpei, Xiang, E-mail: xiangqingpei@163.com [Institute of Nuclear Physics and Chemistry, China and Academy of Engineer Physics, Mianyang 621900 (China)

2017-03-01

The phoswich coincidence detector is used to verify the CTBT treaty by measuring radioxenon and as such needs to possess high detection sensitivity. However, residual xenon adsorbed onto the surface of β detectors greatly influences subsequent measurements of weak samples. In this study, we investigate the adsorption-desorption behavior of xenon on BC-404 scintillator surfaces with different coating thicknesses using the soaking method. The results present the desorption behavior of xenon on a BC-404 surface for the first time. The calculated adsorption capacity for an uncoated surface is consistent with that from previous studies. However, due to factors such as limitations in coating technology, the effectiveness of coating on reducing the “memory effect” of the detector was poor. The proposed method is suitable for studying the adsorption-desorption behavior of gases on solid surfaces due to its simplicity and flexibility. - Highlights: • We investigate the adsorption-desorption of xenon on coated BC-404 surfaces. • The calculated adsorption capacity on an uncoated surface agrees with other results. • The method can be used to simulate xenon adsorption in phoswich detectors.

Bonding xenon and krypton on the surface of uranium dioxide single crystal

Directory of Open Access Journals (Sweden)

Dąbrowski Ludwik

2014-08-01

Full Text Available We present density functional theory (DFT calculation results of krypton and xenon atoms interaction on the surface of uranium dioxide single crystal. A pseudo-potential approach in the generalised gradient approximation (GGA was applied using the ABINIT program package. To compute the unit cell parameters, the 25 atom super-cell was chosen. It has been revealed that close to the surface of a potential well is formed for xenon and krypton atom due to its interaction with the atoms of oxygen and uranium. Depth and shape of the well is the subject of ab initio calculations in adiabatic approximation. The calculations were performed both for the case of oxygenic and metallic surfaces. It has been shown that the potential well for the oxygenic surface is deeper than for the metallic surface. The thermal stability of immobilising the atoms of krypton and xenon in the potential wells were evaluated. The results are shown in graphs.

40 CFR 129.101 - DDT, DDD and DDE.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 21 2010-07-01 2010-07-01 false DDT, DDD and DDE. 129.101 Section 129... POLLUTANT EFFLUENT STANDARDS Toxic Pollutant Effluent Standards and Prohibitions § 129.101 DDT, DDD and DDE. (a) Specialized definitions. (1) DDT Manufacturer means a manufacturer, excluding any source which is...

31 CFR 129.6 - Penalties specified by law.

Science.gov (United States)

2010-07-01

... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Penalties specified by law. 129.6 Section 129.6 Money and Finance: Treasury Regulations Relating to Money and Finance PORTFOLIO INVESTMENT SURVEY REPORTING § 129.6 Penalties specified by law. Reporters are advised that the Act provides the...

Research on the measurement of the ultraviolet irradiance in the xenon lamp aging test chamber

Science.gov (United States)

Ji, Muyao; Li, Tiecheng; Lin, Fangsheng; Yin, Dejin; Cheng, Weihai; Huang, Biyong; Lai, Lei; Xia, Ming

2018-01-01

This paper briefly introduces the methods of calibrating the irradiance in the Xenon lamp aging test chamber. And the irradiance under ultraviolet region is mainly researched. Three different detectors whose response wave range are respectively UVA (320 400nm), UVB (275 330nm) and UVA+B (280 400nm) are used in the experiment. Through comparing the measuring results with different detectors under the same xenon lamp source, we discuss the difference between UVA, UVB and UVA+B on the basis of the spectrum of the xenon lamp and the response curve of the detectors. We also point out the possible error source, when use these detectors to calibrate the chamber.

Contribution to the study on the flow rate adjustment for gas cooled power reactors (1964); Contributiom a l'etude de reglage du debit pour les reacteurs industriels refroidis par gaz (1964)

Energy Technology Data Exchange (ETDEWEB)

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

1961-06-15

1. This original study firstly defines the problem of the adjustment of the coolant flow rate in a reactor channel as a function of the corresponding heat transfer equations and of the local and temporal neutron flux. The necessity of such an adjustment is pointed out and the modifying parameters are studied. An adjustment study using the envelope of the possible flux curves is developed. A short study on the technology and the economical advantage of this adjustment is presented. Some measurements, made on G-1 and G-2, show the precision one can obtain from adjustment apparatus itself as well as from the complete reactor adjustment system. 2. Evolution of nuclear properties of fuel in an heterogeneous thermal reactor. In the first port of this paper, the phenomena of fuel evolution have been mainly pointed out. Now a bibliographical study more qualitatively than quantitatively has been done. This survey specifies the present theories and relates to a real effective cross section and also yields to the bases of such a nuclear calculation. (author) [French] 1. Cette etude originale definit d'abord le probleme du reglage du debit de refrigerant dans un canal de reacteur en fonction de la formulation du calcul des performances thermodynamiques de ce canal et des variations du flux neutronique dans l'espace et le temps. La necessite du reglage est ensuite mise en evidence et les parametres le modifiant sont etudies. Une methode de reglage, basee sur l'emploi d 'une courbe enveloppe des courbes de flux possibles, est donnee. Une breve etude de la technologie et des incidences economiques du reglage est presentee. Des mesures effectuees sur les reacteurs G-1 et G-2 montrent la precision que l'on peut attendre des dispositifs de reglage comme du reglage d'ensemble du reacteur lui-meme. 2. Evolution des proprietes nucleaires du combustible dans un reacteur heterogene a neutrons thermiques. Les phenomenes d'evolution du combustible

Effet du Pediococcus acidilactici sur le bilan lipidique sanguin du ...

African Journals Online (AJOL)

Les résultats relatifs aux performances zootechniques ont montré que l'addition du probiotique a amélioré significativement le gain de poids pendant la phase de croissance se traduisant par un indice de consommation meilleur. Les dosages du cholestérol total, des triglycérides, du HDL et du LDL ont été déterminés à la ...

Study of the short-lived fission products. Separation of iodine and xenon fission radionuclides

International Nuclear Information System (INIS)

Barrachina, M.; Villar, M. A.

1965-01-01

The separation by distillation in a sulfuric acid or phosphoric acid-hydrogen peroxide medium of the iodine isotopes (8 day iodine-131, 2,3 hour iodine-132 21 hour iodine-133, 53 minute iodine-134 and 6,7 hour iodine-135) present in a uranium sample after different irradiation and cooling times is here described. It is also reported the use of active charcoal columns for the retention of xenon isotopes (5,27 days xenon-133 and 9,2 hours xenon-135) either released during the dissolution of the uranium irradiated samples or generated along the fission isobaric chains in the solutions of distillated iodine. In both cases the radiochemical purity of the separated products is established by gamma spectrometry. (Author) 15 refs

Xenon NMR measurements of permeability and tortuosity in reservoir rocks.

Science.gov (United States)

Wang, Ruopeng; Pavlin, Tina; Rosen, Matthew Scott; Mair, Ross William; Cory, David G; Walsworth, Ronald Lee

2005-02-01

In this work we present measurements of permeability, effective porosity and tortuosity on a variety of rock samples using NMR/MRI of thermal and laser-polarized gas. Permeability and effective porosity are measured simultaneously using MRI to monitor the inflow of laser-polarized xenon into the rock core. Tortuosity is determined from measurements of the time-dependent diffusion coefficient using thermal xenon in sealed samples. The initial results from a limited number of rocks indicate inverse correlations between tortuosity and both effective porosity and permeability. Further studies to widen the number of types of rocks studied may eventually aid in explaining the poorly understood connection between permeability and tortuosity of rock cores.

Configuration interaction in charge exchange spectra of tin and xenon

Science.gov (United States)

D'Arcy, R.; Morris, O.; Ohashi, H.; Suda, S.; Tanuma, H.; Fujioka, S.; Nishimura, H.; Nishihara, K.; Suzuki, C.; Kato, T.; Koike, F.; O'Sullivan, G.

2011-06-01

Charge-state-specific extreme ultraviolet spectra from both tin ions and xenon ions have been recorded at Tokyo Metropolitan University. The electron cyclotron resonance source spectra were produced from charge exchange collisions between the ions and rare gas target atoms. To identify unknown spectral lines of tin and xenon, atomic structure calculations were performed for Sn14+-Sn17+ and Xe16+-Xe20+ using the Hartree-Fock configuration interaction code of Cowan (1981 The Theory of Atomic Structure and Spectra (Berkeley, CA: University of California Press)). The energies of the capture states involved in the single-electron process that occurs in these slow collisions were estimated using the classical over-barrier model.

7 CFR 1220.129 - State and United States.

Science.gov (United States)

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false State and United States. 1220.129 Section 1220.129... CONSUMER INFORMATION Soybean Promotion and Research Order Definitions § 1220.129 State and United States. The terms State and United States include the 50 States of the United States of America, the District...

Pulse Rise Time Characterization of a High Pressure Xenon Gamma Detector for use in Resolution Enhancement

CERN Document Server

Troyer, G L

2000-01-01

High pressure xenon ionization chamber detectors are possible alternatives to traditional thallium doped sodium iodide (NaI(Tl)) and hyperpure germanium as gamma spectrometers in certain applications. Xenon detectors incorporating a Frisch grid exhibit energy resolutions comparable to cadmium/zinc/telluride (CZT) (e.g. 2% (at) 662keV) but with far greater sensitive volumes. The Frisch grid reduces the position dependence of the anode pulse risetimes, but it also increases the detector vibration sensitivity, anode capacitance, voltage requirements and mechanical complexity. We have been investigating the possibility of eliminating the grid electrode in high-pressure xenon detectors and preserving the high energy resolution using electronic risetime compensation methods. A two-electrode cylindrical high pressure xenon gamma detector coupled to time-to-amplitude conversion electronics was used to characterize the pulse rise time of deposited gamma photons. Time discrimination was used to characterize the pulse r...

Matrix of response functions for xenon gamma-ray detector

International Nuclear Information System (INIS)

Shustov, A.E.; Vlasik, K.F.; Grachev, V.M.; Dmitrenko, V.V.; Novikov, A.S.; P'ya, S.N.; Ulin, S.E.; Uteshev, Z.M.; Chernysheva, I.V.

2014-01-01

An approach of creation of response matrix using simulation GEANT4 gamma-ray Monte-Carlo method has been described for gamma-ray spectrometer based on high pressure xenon impulse ionization chamber with a shielding grid [ru

Alimentation du nouveau-ne et du nourrisson dans la region ...

African Journals Online (AJOL)

Alimentation du nouveau-ne et du nourrisson dans la region centrale du togo : pratiques familiales et communautaires avant la mise en oeuvre de la strategie « prise en charge integree des maladies de l'enfant »

Supernova Neutrino Physics with Xenon Dark Matter Detectors

NARCIS (Netherlands)

Reichard, S.; Lang, R.F.; McCabe, C.; Selvi, M.; Tamborra, I.

2017-01-01

The dark matter experiment XENON1T is operational and sensitive to all flavors of neutrinos emitted from a supernova. We show that the proportional scintillation signal (S2) allows for a clear observation of the neutrino signal and guarantees a particularly low energy threshold, while the

First Axion Results from the XENON100 Experiment

CERN Document Server

Aprile, E.; Alfonsi, M.; Arisaka, K.; Arneodo, F.; Auger, M.; Balan, C.; Barrow, P.; Baudis, L.; Bauermeister, B.; Behrens, A.; Beltrame, P.; Bokeloh, K.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Cardoso, J.M.R.; Colijn, A.P.; Contreras, H.; Cussonneau, J.P.; Decowski, M.P.; Duchovni, E.; Fattori, S.; Ferella, A.D.; Fulgione, W.; Gao, F.; Garbini, M.; Geis, C.; Goetzke, L.W.; Grignon, C.; Gross, E.; Hampel, W.; Itay, R.; Kaether, F.; Kessler, G.; Kish, A.; Landsman, H.; Lang, R.F.; Calloch, M. Le; Lellouch, D.; Levy, C.; Lindemann, S.; Lindner, M.; Lopes, J.A.M.; Lung, K.; Lyashenko, A.; Macmullin, S.; Marrodan Undagoitia, T.; Masbou, J.; Massoli, F.V.; Mayani Paras, D.; Melgarejo Fernandez, A. J.; Meng, Y.; Messina, M.; Miguez, B.; Molinario, A.; Murra, M.; Naganoma, J.; Oberlack, U.; Orrigo, S.E.A.; Pantic, E.; Persiani, R.; Piastra, F.; Pienaar, J.; Plante, G.; Priel, N.; Reichard, S.; Reuter, C.; Rizzo, A.; Rosendahl, S.; dos Santos, J. M. F.; Sartorelli, G.; Schindler, S.; Schreiner, J.; Schumann, M.; Scotto Lavina, L.; Selvi, M.; Shagin, P.; Simgen, H.; Teymourian, A.; Thers, D.; Tiseni, A.; Trinchero, G.; Vitells, O.; Wang, H.; Weber, M.; Weinheimer, C.

2014-09-09

We present the first results of searches for axions and axion-like-particles with the XENON100 experiment. The axion-electron coupling constant, $g_{Ae}$, has been tested by exploiting the axio-electric effect in liquid xenon. A profile likelihood analysis of 224.6 live days $\\times$ 34 kg exposure has shown no evidence for a signal. By rejecting $g_{Ae}$, larger than $7.7 \\times 10^{-12}$ (90% CL) in the solar axion search, we set the best limit to date on this coupling. In the frame of the DFSZ and KSVZ models, we exclude QCD axions heavier than 0.3 eV/c$^2$ and 80 eV/c$^2$, respectively. For axion-like-particles, under the assumption that they constitute the whole abundance of dark matter in our galaxy, we constrain $g_{Ae}$, to be lower than $1 \\times 10^{-12}$ (90% CL) for masses between 5 and 10 keV/c$^2$.

Ventilation imaging of the paranasal sinuses using xenon-enhanced dynamic single-energy CT and dual-energy CT: a feasibility study in a nasal cast

Energy Technology Data Exchange (ETDEWEB)

Thieme, Sven F.; Helck, Andreas D.; Reiser, Maximilian F.; Johnson, Thorsten R.C. [Ludwig Maximilians University Hospital Munich, Institute for Clinical Radiology, Munich (Germany); Moeller, Winfried; Eickelberg, Oliver [Institute for Lung Biology and Disease (iLBD) and Comprehensive Pneumology Center (CPC), Helmholtz Zentrum Muenchen, Neuherberg, Munich (Germany); Becker, Sven [Ludwig-Maximilians-Universitaet, Department of Otorhinolaryngology - Head and Neck Surgery, Munich (Germany); Schuschnig, Uwe [Pari Pharma GmbH, Graefelfing (Germany)

2012-10-15

To show the feasibility of dual-energy CT (DECT) and dynamic CT for ventilation imaging of the paranasal sinuses in a nasal cast. In a first trial, xenon gas was administered to a nasal cast with a laminar flow of 7 L/min. Dynamic CT acquisitions of the nasal cavity and the sinuses were performed. This procedure was repeated with pulsating xenon flow. Local xenon concentrations in the different compartments of the model were determined on the basis of the enhancement levels. In a second trial, DECT measurements were performed both during laminar and pulsating xenon administration and the xenon concentrations were quantified directly. Neither with dynamic CT nor DECT could xenon-related enhancement be detected in the sinuses during laminar airflow. Using pulsating flow, dynamic imaging showed a xenon wash-in and wash-out in the sinuses that followed a mono-exponential function with time constants of a few seconds. Accordingly, DECT revealed xenon enhancement in the sinuses only after pulsating xenon administration. The feasibility of xenon-enhanced DECT for ventilation imaging was proven in a nasal cast. The superiority of pulsating gas flow for the administration of gas or aerosolised drugs to the paranasal sinuses was demonstrated. (orig.)

Modeling Xenon Tank Pressurization using One-Dimensional Thermodynamic and Heat Transfer Equations

Science.gov (United States)

Gilligan, Ryan P.; Tomsik, Thomas M.

2017-01-01

As a first step in understanding what ground support equipment (GSE) is required to provide external cooling during the loading of 5,000 kg of xenon into 4 aluminum lined composite overwrapped pressure vessels (COPVs), a modeling analysis was performed using Microsoft Excel. The goals of the analysis were to predict xenon temperature and pressure throughout loading at the launch facility, estimate the time required to load one tank, and to get an early estimate of what provisions for cooling xenon might be needed while the tanks are being filled. The model uses the governing thermodynamic and heat transfer equations to achieve these goals. Results indicate that a single tank can be loaded in about 15 hours with reasonable external coolant requirements. The model developed in this study was successfully validated against flight and test data. The first data set is from the Dawn mission which also utilizes solar electric propulsion with xenon propellant, and the second is test data from the rapid loading of a hydrogen cylindrical COPV. The main benefit of this type of model is that the governing physical equations using bulk fluid solid temperatures can provide a quick and accurate estimate of the state of the propellant throughout loading which is much cheaper in terms of computational time and licensing costs than a Computation Fluid Dynamics (CFD) analysis while capturing the majority of the thermodynamics and heat transfer.

Excess 129Xe in terrestrial samples: A non-primordial hypothesis

International Nuclear Information System (INIS)

Caffee, M.W.; Hudson, G.B.

1987-03-01

Excesses of 129 Xe relative to the isotopic composition in air are observed in some terrestrial samples. Traditionally these 129 Xe excesses have been thought to be related to 129 I that was present in abundance in the early solar system. We propose an alternative hypothesis to explain terrestrial 129 Xe excesses based on the production of 129 I from the spontaneous fission of 238 U

Quantitative analysis of dynamic airway changes after methacholine and salbutamol inhalation on xenon-enhanced chest CT

Energy Technology Data Exchange (ETDEWEB)

Park, Sang Joon; Goo, Jin Mo; Kim, Jong Hyo; Park, Eun-Ah [Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Seoul National University College of Medicine, Institute of Radiation Medicine, Medical Research Center, Seoul (Korea, Republic of); Lee, Chang Hyun [Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Seoul National University College of Medicine, Institute of Radiation Medicine, Medical Research Center, Seoul (Korea, Republic of); Seoul National University Hospital, Healthcare Gangnam Center, Seoul (Korea, Republic of); Jung, Jae-Woo; Park, Heung-Woo [Seoul National University College of Medicine, Department of Internal Medicine, Seoul (Korea, Republic of); Seoul National University College of Medicine, Institute of Allergy and Clinical Immunology, Seoul (Korea, Republic of); Cho, Sang-Heon [Seoul National University Hospital, Healthcare Gangnam Center, Seoul (Korea, Republic of); Seoul National University College of Medicine, Department of Internal Medicine, Seoul (Korea, Republic of); Seoul National University College of Medicine, Institute of Allergy and Clinical Immunology, Seoul (Korea, Republic of)

2012-11-15

To investigate the dynamic changes in airways in response to methacholine and salbutamol inhalation and to correlate the xenon ventilation index on xenon-enhanced chest CTs in asthmatics. Thirty-one non-smokers (6 normal, 25 asthmatics) underwent xenon-enhanced chest CT and pulmonary function tests. Images were obtained at three stages (basal state, after methacholine inhalation and after salbutamol inhalation), and the total xenon ventilation index (TXVI) as well as airway values were measured and calculated. The repeated measures ANOVA and Spearman's correlation coefficient were used for statistical analysis. TXVI in the normal group did not significantly change (P > 0.05) with methacholine and salbutamol. For asthmatics, however, the TXVI significantly decreased after methacholine inhalation and increased after salbutamol inhalation (P < 0.05). Of the airway parameters, the airway inner area (IA) significantly increased after salbutamol inhalation in all airways (P < 0.01) in asthmatics. Airway IA, wall thickness and wall area percentage did not significantly decrease after methacholine inhalation (P > 0.05). IA of the large airways was well correlated with basal TXVI, FEV{sub 1} and FVC (P < 0.05). Airway IA is the most reliable parameter for reflecting the dynamic changes after methacholine and salbutamol inhalation, and correlates well with TXVI in asthmatics on xenon-enhanced CT. (orig.)

Investigations on the 129I radioecology

International Nuclear Information System (INIS)

Schuettelkopf, H.

1977-01-01

The measurement of 129 I concentrations in milk and soil samples was continued. In process solutions of the Karlsruhe Reprocessing Plant the 129 I concentrations were determined. 127 I was measured in air. Apparatus for the collection of 127 I in air were installed in Kiel, Stade and Gundremmingen. The concentrations of 129 I in goats milk were between 0.03 and 1.1 pCi/g. The soil sample concentrations were between 0.3 and 5.6 fCi/g. The concentrations of 127 I in air from the environment of the Karlsruhe Nuclear Research Center averages about 10 ng I 2 /m 3 and about 2 ng aerosol bound I/m 3 . (orig./RW) [de

Thermal decomposition of uranyl nitrate hexahydrate. Study of intermediate reaction products; Decomposition thermique du nitrate d'uranyle hexahydrate etude des intermediaires de cette decomposition

Energy Technology Data Exchange (ETDEWEB)

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

1970-07-01

The thermal decomposition of uranyl nitrate hexahydrate has been carried but at constant pressure and constant rate of reaction. The following intermediary products have been shown to exist and isolated: UO{sub 2}(NO{sub 3}){sub 2}.3H{sub 2}O; UO{sub 2}(NO{sub 3}){sub 2}. 2H{sub 2}O; UO{sub 2}(NO{sub 3}){sub 2}. H{sub 2}O; UO{sub 2}(NO{sub 3}){sub 2} and UO{sub 3}. These products, together with the hexahydrate UO{sub 2} (NO{sub 3}){sub 2}.6H{sub 2}O, have been studied by: - X-ray diffraction, using the Debye-Scherrer method.- infra-red spectrography: determination of the type of bonding for the water and the nitrate groups. - nuclear magnetic resonance: study of the mobility of water molecules. The main results concern: - the water molecule bonds in the series of hydrates with 6.3 and 2 H{sub 2}O. - isolation and characterization of uranyl nitrate monohydrate, together with the determination of its molecular structure. - the mobility of the water molecules in the series of the hydrates with 6.3 and 2 H{sub 2}O. An analysis is made of the complementary results given by infra-red spectroscopy and nuclear magnetic resonance; they are interpreted for the whole of the hydrate series. [French] La decomposition thermique du nitrate d'uranyle hexahydrate a ete effectuee en operant a pression et vitesse de decomposition constantes. Les produits intermediaires suivants ont ete mis en evidence et isoles: UO{sub 2}(NO{sub 3}){sub 2}, 3H{sub 2}O; UO{sub 2}(NO{sub 3}){sub 2}, 2H{sub 2}O; UO{sub 2}(NO{sub 3}){sub 2},H{sub 2}O; UO{sub 2}(NO{sub 3}){sub 2} et UO{sub 3}. Ces composes, ainsi que l'hexahydrate UO{sub 2}(NO{sub 3} ){sub 2}, 6H{sub 2}O ont ete etudies par: - diffraction des rayons X, selon la methode Debye-Scherrer.- spectrographie infra-rouge: determination des modes de liaison de l'eau et des groupements nitrate. - resonance magnetique nucleaire: etude de la mobilite des molecules d'eau. Les principaux resultats portent sur: - les liaisons des molecules d'eau dans la

Portage vaginal du streptocoque du groupe B chez la femme ...

African Journals Online (AJOL)

Introduction: le streptocoque du groupe B est le principal agent impliqué dans les infections materno-fœtales, les septicémies et les méningites du nouveau-né à terme. L'objectif est de déterminer le taux de portage maternel du streptocoque du groupe B (SGB) à terme. Méthodes: un prélèvement vaginal a été réalisé de ...

Reflectance measurements of PTFE, Kapton, and PEEK for xenon scintillation light for the LZ detector.

Science.gov (United States)

Arthurs, M.; Batista, E.; Haefner, J.; Lorenzon, W.; Morton, D.; Neff, A.; Okunawo, M.; Pushkin, K.; Sander, A.; Stephenson, S.; Wang, Y.; LZ Collaboration

2017-01-01

LZ (LUX-Zeplin) is an international collaboration that will look for dark matter candidates, WIMPs (Weakly Interacting Massive Particles), through direct detection by dual-phase time projection chamber (TPC) using liquid xenon. The LZ detector will be located nearly a mile underground at SURF, South Dakota, shielded from cosmic background radiation. Seven tons active mass of liquid xenon will be used for detecting the weak interaction of WIMPs with ordinary matter. Over three years of operation it is expected to reach the ultimate sensitivity of 2x10-48 cm2 for a WIMP mass of 50 GeV. As for many other rare event searches, high light collection efficiency is essential for LZ detector. Moreover, in order to achieve greater active volume for detection as well as reduce potential backgrounds, thinner detector walls without significant loss in reflectance are desired. Reflectance measurements of polytetrafluoroethylene (PTFE), Kapton, and PEEK for xenon scintillation light (178 nm), conducted at the University of Michigan using the Michigan Xenon Detector (MiX) will be presented. The University of Michigan, LZ Collaboration, The US Department of Energy.

Economic Criteria Applied to Nuclear Materials Management; Criteres Economiques Applicables a la Gestion des Matieres Nucleaires; Ehkonomicheskie kriterii, primenyaemye pri kontrole i uchete yadernykh materialov; Criterios Economicos Aplicados a la Administracion de Materiales Nucleares

Energy Technology Data Exchange (ETDEWEB)

Shelley, W. J.; Kuehn, M. N. [Mallinckrodt Chemical Works, St. Charles, MS (United States)

1966-02-15

placed upon such personnel to accept, understand and perform the work. Such personnel selected must be thoroughly and minutely trained in the importance of their activity. Those responsible for the management of nuclear materials must be continually alert to the smallest kind of aberration in the quality and performance of the personnel, the process, the systems, procedures and techniques. Only through such alertness and willingness to revise, so as to secure improvement, does one secure the optimum balance of costs and needs. (author) [French] La gestion des matieres nucleaires doit etre subordonnee aux objectifs principaux du traitement de ces matieres, c'est-a-dire la production d'energie ou la fabrication de produits finis. Les responsables de la gestion des matieres nucleaires doivent donc tenir constamment compte des besoins de la production principale et adapter les methodes de gestion aux operations de facon a pouvoir assurer cette gestion avec un minimum de depenses. Le systeme de gestion des matieres nucleaires doit soigneusement tenir compte des divers facteurs qui influent sur son prix de revient. Il vient en complement des operations et doit entrainer le minimum de frais de personnel et d'analyse et provoquer le moins d'interruptions possible dans les operations. U doit etre integre a ces dernieres, de facon que les renseignements d'ordre quantitatif qu'il permet d'obtenir puissent etre communiques rapidement aux responsables du controle des operations. Le systeme d'enregistrement et de preparation des rapports doit fournir une quantite maximale de donnees subsidiaires. Il doit etre compatible avec les systemes utilises par les fournisseurs et les consommateurs et assurer la diffusion, partout ou cela est possible, de renseignements supplementaires concernant les lots de matieres nucleaires. Les donnees a fournir pour le controle des matieres nucleaires doivent se limiter a celles qui sont necessaires pour s'assurer qu'il n'y a pas de pertes importantes, de

Build up of Radioactive Krypton and Xenon Analysis System

International Nuclear Information System (INIS)

Lee, D. K.; Choi, C. S.; Chung, K. H.; Lee, W.; Cho, Y. H.; Lee, C. W.

2008-03-01

The objective of this project is to build up an analysis system to measure the activity of the atmospheric radioactive krypton and xenon in Korea. The work scopes of the project include the purchase and the installation of the analysis system to measure the activity of the radioactive krypton and xenon in air, and the establishment of the operation capability of the system through the training of the operator. The system consists of two air sampling systems, and one radioactivity analysis system, which incorporates the enrichment system, the gas chromatography to purify a mixture gas, and the gas proportional counter to count the activity of pure krypton and xenon gas. As planned originally, the establishment of the analysis system has been completed. At present, one air sampler is successfully being operated at a specific site of the South Korea to measure the background radioactivities of Kr-85 and Xe-133 in air. The other air sampler is being reserved at the KAERI in the Daejeon for a emergency like the second nuclear test of the North Korea. During the normal time, the reserved air sampler will be used to collect the air sample for the performance test of the analysis system and the cross analysis for the calibration of the system. The radioactivity analysis system has been installed at the KAERI, and is being used to measure the activity of Kr-85 and Xe-133 in the air sample from a domestic site

Two-photon resonant, stimulated processes in krypton and xenon

International Nuclear Information System (INIS)

Miller, J.C.

1988-11-01

Both on-axis and conical emissions have been observed following two-photon pumping of the 5p states of krypton and the 6p', 7p, 8p, and 4f states of xenon. In the former case, coherent emissions from the 5p states to the 5s are observed, and in the latter case, many p→s, d→p, and f→d cascade emissions are observed. By analogy to the well-studied alkali and alkaline earth examples, the emissions are discussed in terms of amplified spontaneous emission (ASE), stimulated hyper-Raman scattering, and parametric four-wave mixing. The physical processes responsible for the conical emission and for intensity anomalies in the xenon p→s emissions are not understood at present. Interference effects due to coherent cancellation between competing excitation pathways may be occurring. 4 refs., 3 figs

Search for magnetic inelastic dark matter with XENON100

Energy Technology Data Exchange (ETDEWEB)

Aprile, E.; Anthony, M. [Physics Department, Columbia University, New York, NY 10027 (United States); Aalbers, J.; Breur, P.A.; Brown, A. [Nikhef and the University of Amsterdam, Science Park, 1098XG Amsterdam (Netherlands); Agostini, F.; Bruno, G. [INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, 67100 L' Aquila (Italy); Alfonsi, M. [Institut für Physik and Exzellenzcluster PRISMA, Johannes Gutenberg-Universität Mainz, 55099 Mainz (Germany); Amaro, F.D. [LIBPhys, Department of Physics, University of Coimbra, 3004-516 Coimbra (Portugal); Arneodo, F.; Benabderrahmane, M.L. [New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Barrow, P.; Baudis, L. [Physik-Institut, University of Zurich, 8057 Zurich (Switzerland); Bauermeister, B.; Calvén, J. [Oskar Klein Centre, Department of Physics, Stockholm University, AlbaNova, Stockholm SE-10691 (Sweden); Berger, T.; Brown, E. [Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, NY 12180 (United States); Bruenner, S. [Max-Planck-Institut für Kernphysik, 69117 Heidelberg (Germany); Budnik, R. [Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot 7610001 (Israel); Bütikofer, L., E-mail: lukas.buetikofer@lhep.unibe.ch, E-mail: xenon@lngs.infn.it [Physikalisches Institut, Universität Freiburg, 79104 Freiburg (Germany); and others

2017-10-01

We present the first search for dark matter-induced delayed coincidence signals in a dual-phase xenon time projection chamber, using the 224.6 live days of the XENON100 science run II. This very distinct signature is predicted in the framework of magnetic inelastic dark matter which has been proposed to reconcile the modulation signal reported by the DAMA/LIBRA collaboration with the null results from other direct detection experiments. No candidate event has been found in the region of interest and upper limits on the WIMP's magnetic dipole moment are derived. The scenarios proposed to explain the DAMA/LIBRA modulation signal by magnetic inelastic dark matter interactions of WIMPs with masses of 58.0 GeV/c{sup 2} and 122.7 GeV/c{sup 2} are excluded at 3.3 σ and 9.3 σ, respectively.

Dark matter sensitivity of multi-ton liquid xenon detectors

International Nuclear Information System (INIS)

Schumann, Marc; Bütikofer, Lukas; Baudis, Laura; Kish, Alexander; Selvi, Marco

2015-01-01

We study the sensitivity of multi ton-scale time projection chambers using a liquid xenon target, e.g., the proposed DARWIN instrument, to spin-independent and spin-dependent WIMP-nucleon scattering interactions. Taking into account realistic backgrounds from the detector itself as well as from neutrinos, we examine the impact of exposure, energy threshold, background rejection efficiency and energy resolution on the dark matter sensitivity. With an exposure of 200 t × y and assuming detector parameters which have been already demonstrated experimentally, spin-independent cross sections as low as 2.5 × 10 −49 cm 2 can be probed for WIMP masses around 40 GeV/c 2 . Additional improvements in terms of background rejection and exposure will further increase the sensitivity, while the ultimate WIMP science reach will be limited by neutrinos scattering coherently off the xenon nuclei

Analysis and separation of boron isotopes; Analyse et separation des isotopes du bore

Energy Technology Data Exchange (ETDEWEB)

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

1966-11-01

The nuclear applications of boron-10 justify the study of a method of measurement of its isotopic abundance as well as of very small traces of boron in different materials. A systematic study of thermionic emission of BO{sub 2}Na{sub 2}{sup +} has been carried out. In the presence of a slight excess of alkalis, the thermionic emission is considerably reduced. On the other hand, the addition of a mixture of sodium hydroxide-glycerol (or mannitol) to borax permits to obtain an intense and stable beam. These results have permitted to establish an operative method for the analysis of traces of boron by isotopic dilution. In other respects, the needs of boron-10 in nuclear industry Justify the study of procedures of separation of isotopes of boron. A considerable isotopic effect has been exhibited in the chemical exchange reaction between methyl borate and borate salt in solution. In the case of exchange between methyl borate and sodium borate, the elementary separation factor {alpha} is: {alpha}=(({sup 11}B/{sup 10}B)vap.)/(({sup 11}B/{sup 10}B)liq.)=1.03{sub 3}. The high value of this elementary effect has been multiplied in a distillation column in which the problem of regeneration of the reactive has been resolved. An alternative procedure replacing the alkali borate by a borate of volatile base, for example diethylamine, has also been studied ({alpha}=1,02{sub 5} in medium hydro-methanolic with 2,2 per cent water). (author) [French] Les applications nucleaires du bore 10 justifient l'etude d'une methode de mesure de son abondance isotopique dans divers materiaux ainsi que le dosage de tres faibles traces de bore. Une etude systematique de l'emission thermoionique de BO{sub 2} Na{sub 2}{sup +} a ete effectuee. En presence d'un leger exces d'alcalins, l'emission thermoionique est considerablement reduite. Par contre l'addition au borax d'un melange soude-glycerol (ou mannitol) permet d'obtenir un faisceau stable et intense. Ces resultats ont permis d'etablir un mode

129I Interlaboratory comparison: phase I and phase II

International Nuclear Information System (INIS)

Caffee, M. W.; Roberts, M. L.

1999-01-01

An interlaboratory comparison exercise for 129 I was organized and conducted. Nine laboratories participated in the exercise to either a full or limited extent. In Phase I of the comparison, 11 samples were measured. The suite of samples contained both synthetic ''standard type'' materials (i.e., AgI) and environmental materials. The isotopic 129 I/ 127 I ratios of the samples varied from 10 -8 to 10 -14 . In this phase, each laboratory was responsible for its own chemical preparation of the samples. In Phase I, the 129 I AMS measurements for prepared AgI were in good agreement. However, large discrepancies were seen in 129 I AMS measurements of environmental samples. Because of the large discrepancies seen in the Phase I 129 I intercomparison, a subsequent study was conducted. In Phase II of the 129 I intercomparison, three separate laboratories prepared AgI from two environmental samples (IAEA 375 soil and maples leaves). Each laboratory used its own chemical preparation method with each of the methods being distinctly different. The resulting six samples (two sets of three) were then re-distributed to the participating 129 I AMS facilities and 129 I/ 127 I ratios measured. Results and discussion of both the Phase I and Phase II interlaboratory comparison are presented

Investigations on iodine-129 in the biosphere

International Nuclear Information System (INIS)

Handl, J.; Oliver, E.; Jakob, D.

1992-01-01

In order to detect characteristic regional differences or temporal changes of iodine-129 concentrations in the biosphere, thyroids from humans, grazing livestock and roedeer (Capreolus capreolus L.) are collected in various parts of the world, which are differing in the exposure to I-129 immissions from nuclear sources. For reasons of comparison all samples are analysed for their I-129/I-127 atom ratios. Human thyroids taken from Lower Saxony (Federal Republic of Germany), which is a region not directly affected by reprocessing plants showed I-129/I-127 values between 8x10 -9 and 6x10 -8 for a period from February 1988 to September 1990. Those atom ratios correspond to the level of biospheric I-129 in background areas of Europe exposed to fallout atmospheric nuclear weapons tests during the 1950s and 1960s. Thyroid glands of roedeer taken from the Heby commune in Middle Sweden during spring 1990 showed I-129/I-127 ratios between 2x10 -7 and 4x10 -7 . Two soil samples taken from Krasnaya Gora and Mirny locations in Russia (about 200 km northwest of Chernobyl) exhibited ratios of about 1x10 -6 . According to the Cs-137 levels, the Swedish Heby area as well as both Russian locations were found to be seriously Chernobyl contaminated. Ratios found in human and bovine thyroids collected in the 10th Region in southern Chile (40deg-42degS) indicated values between 1x10 -10 and 9x10 -9 . On the basis of the prenuclear range of I-129/I-127 ratios between 4x10 -11 and 3x10 -9 , which were found in human thyroids analysed in the USA before 1945 the Chilean values can be considered only slightly elevated as compared to those determined in samples of Northern Hemisphere today. (orig.) [de

Scintillating liquid xenon calorimeter for precise electron/photon/jet physics at high energy high luminosity hadron colliders

International Nuclear Information System (INIS)

Chen, M.; Luckey, D.; Pelly, D.; Shotkin, S.; Sumorok, K.; Wadsworth, B.; Yan, X.J.; You, C.; Zhang, X.; Chen, E.G.; Gaudreau, M.P.J.; Montgomery, D.B.; Sullivan, J.D.; Bolozdynya, A.; Chernyshev, V.; Goritchev, P.; Khovansky, V.; Kouchenkov, A.; Kovalenko, A.; Lebedenko, V.; Vinogradov, V.A.; Epstein, V.; Zeldovich, S.; Krasnokutsky, R.; Shuvalov, R.; Aprile, E.; Mukherjee, R.; Suzuki, M.; Moulsen, M.; Sugimoto, S.; Okada, K.; Fujino, T.; Matsuda, T.; Miyajima, M.; Doke, T.; Kikuchi, J.; Hitachi, A.; Kashiwagi, T.; Nagasawa, Y.; Ichinose, H.; Ishida, N.; Nakasugi, T.; Ito, T.; Masuda, K.; Shibamura, E.; Wallraff, W.; Vivargent, M.; Mutterer, M.; Chen, H.S.; Tang, H.W.; Tung, K.L.; Ding, H.L.; Takahashi, T.

1990-01-01

The authors use αs well as e, π, p, d and heavy ion beams to test prototype scintillating liquid xenon detectors, with large UV photodiodes and fast amplifiers submersed directly in liquid xenon. The data show very large photoelectron yields (10 7 /GeV) and high energy resolution (σ(E)/E 1.6 GeV). The α spectra are stable over long term and can be used to calibrate the detectors. Full size liquid xenon detectors have been constructed, to study cosmic μ's and heavy ions. The authors report the progress on the design and construction of the 5 x 5 and 11 x 11 cell liquid xenon detectors which will be tested in high energy beams to determine the e/π ratio. The authors describe the design and the unique properties of the proposed scintillating LXe calorimeter for the SSC

Study of emission of a volume nanosecond discharge plasma in xenon, krypton and argon at high pressures

International Nuclear Information System (INIS)

Baksht, E Kh; Lomaev, Mikhail I; Rybka, D V; Tarasenko, Viktor F

2006-01-01

The emission properties of a volume nanosecond discharge plasma produced in xenon, krypton and argon at high pressures in a discharge gap with a cathode having a small radius of curvature are studied. Spectra in the range 120-850 nm and amplitude-time characteristics of xenon emission at different regimes and excitation techniques are recorded and analysed. It is shown that upon excitation of the volume discharge initiated by a beam of avalanche electrons, at least 90% of the energy in the spectral range 120-850 nm is emitted by xenon dimers. For xenon at a pressure of 1.2 atm, ∼45 mJ of the spontaneous emission energy was obtained in the full solid angle in a pulse with the full width at half-maximum ∼130 ns. (laser applications and other topics in quantum electronics)

Collateral Ventilation to Congenital Hyperlucent Lung Lesions Assessed on Xenon-Enhanced Dynamic Dual-Energy CT: an Initial Experience

OpenAIRE

Goo, Hyun Woo; Yang, Dong Hyun; Kim, Namkug; Park, Seung Il; Kim, Dong Kwan; Kim, Ellen Ai-Rhan

2011-01-01

Objective We wanted to evaluate the resistance to collateral ventilation in congenital hyperlucent lung lesions and to correlate that with the anatomic findings on xenon-enhanced dynamic dual-energy CT. Materials and Methods Xenon-enhanced dynamic dual-energy CT was successfully and safely performed in eight children (median age: 5.5 years, 4 boys and 4 girls) with congenital hyperlucent lung lesions. Functional assessment of the lung lesions on the xenon map was done, including performing a ...

Iodine-129 as a long-lived tracer in the environment

International Nuclear Information System (INIS)

Michel, R.; Ernst, T.; Szidat; Schnabel, C.; Synal, H.-A.

2002-01-01

129 I is an important tracer of human activities as well of environmental processes. However, its potential can only be exploited if the 129 I abundances in and the pathways between the different environmental compartments are known. Until today, our knowledge of the radioecology of 129 I is still insufficient. Results are presented from a long-term project which shall improve this situation. 129 I and 127 I abundances were investigated in precipitation, surface and ground waters from Lower Saxony, Germany, and in soil samples from various European locations. From the analysis of 129 I in rain, 129 I annual deposition densities were determined for the time period from 1997- 1999. We conclude that 129 I deposition rates in Switzerland and Germany increased by three orders of magnitude since 1950 and changed just little after 1987. The different 129 I/ 127 I ratios in precipitation, surface and ground waters allow to estimate mean residence times of iodine in surface soil zones. From the analysis of soils, 129 I deposition densities at various places of Europe were determined. Thereby, the 129 I natural equilibrium deposition density as well as that of the fall-out from atmospheric weapon tests was estimated. Elevated 129 I abundances in Ukrainian soils contaminated by Chernobyl fall-out provide a basis for retrospective dosimetry of the radiation exposure due to 131 I. Soil profiles from Germany exhibit the influence of ongoing emissions from European reprocessing plants and demonstrate the complexity of iodine migration. Biospheric 129 I/ 127 I ratios in Germany are an order of magnitude lower than in precipitation. Because of the disequilibrium of iodine isotopes in the different compartments further detailed investigations of the pathways of 129 I through the environment to man are considered necessary. (author)

900-L liquid xenon cryogenic system operation for the MEG experiment

CERN Document Server

Haruyama, T; Mihara, S; Hisamatsu, Y; Iawamoto, W; Mori, T; Nishiguchi, H; Otani, W; Sawada, R; Uchiyama, Y; Nishitani, T

2009-01-01

A cryogenic system for the MEG (muon rare decay) experiment has started operation at the Paul Sherrer Institute in Zurich. The main part of the MEG detector is the 900-L liquid xenon calorimeter for gamma ray detection, equipped with 850 photo multipliers directly immersed in liquid xenon. A 200 W pulse tube cryocooler enabled LN2-free operation of this calorimeter. A liquid purification system; using a liquid pump and a zero boil-off 1000-L cryogenic buffer dewar is also included in the system. The first entire engineering run was carried out in November-December 2007 and satisfactory cryogenic performances were confirmed.

Analysis method for beta-gamma coincidence spectra from radio-xenon isotopes

International Nuclear Information System (INIS)

Yang Wenjing; Yin Jingpeng; Huang Xiongliang; Cheng Zhiwei; Shen Maoquan; Zhang Yang

2012-01-01

Radio-xenon isotopes monitoring is one important method for the verification of CTBT, what includes the measurement methods of HPGe γ spectrometer and β-γ coincidence. The article describes the analytic flowchart and method of three-dimensional beta-gamma coincidence spectra from β-γ systems, and analyses in detail the principles and methods of the regions of interest of coincidence spectra and subtracting the interference, finally gives the formula of radioactivity of Xenon isotopes and minimum detectable concentrations. Studying on the principles of three-dimensional beta-gamma coincidence spectra, which can supply the foundation for designing the software of β-γ coincidence systems. (authors)

Crystallographic studies with xenon and nitrous oxide provide evidence for protein-dependent processes in the mechanisms of general anesthesia.

Science.gov (United States)

Abraini, Jacques H; Marassio, Guillaume; David, Helene N; Vallone, Beatrice; Prangé, Thierry; Colloc'h, Nathalie

2014-11-01

The mechanisms by which general anesthetics, including xenon and nitrous oxide, act are only beginning to be discovered. However, structural approaches revealed weak but specific protein-gas interactions. To improve knowledge, we performed x-ray crystallography studies under xenon and nitrous oxide pressure in a series of 10 binding sites within four proteins. Whatever the pressure, we show (1) hydrophobicity of the gas binding sites has a screening effect on xenon and nitrous oxide binding, with a threshold value of 83% beyond which and below which xenon and nitrous oxide, respectively, binds to their sites preferentially compared to each other; (2) xenon and nitrous oxide occupancies are significantly correlated respectively to the product and the ratio of hydrophobicity by volume, indicating that hydrophobicity and volume are binding parameters that complement and oppose each other's effects; and (3) the ratio of occupancy of xenon to nitrous oxide is significantly correlated to hydrophobicity of their binding sites. These data demonstrate that xenon and nitrous oxide obey different binding mechanisms, a finding that argues against all unitary hypotheses of narcosis and anesthesia, and indicate that the Meyer-Overton rule of a high correlation between anesthetic potency and solubility in lipids of general anesthetics is often overinterpreted. This study provides evidence that the mechanisms of gas binding to proteins and therefore of general anesthesia should be considered as the result of a fully reversible interaction between a drug ligand and a receptor as this occurs in classical pharmacology.

Study of the short-lived fission products. Separation of iodine and xenon fission radionuclides; Estudio de los productos de fision de periodo corto. Separacion de los radionuclidos de fision del yodo y del xenon

Energy Technology Data Exchange (ETDEWEB)

Barrachina, M; Villar, M A

1965-07-01

The separation by distillation in a sulfuric acid or phosphoric acid-hydrogen peroxide medium of the iodine isotopes (8 day iodine-131, 2,3 hour iodine-132 21 hour iodine-133, 53 minute iodine-134 and 6,7 hour iodine-135) present in a uranium sample after different irradiation and cooling times is here described. It is also reported the use of active charcoal columns for the retention of xenon isotopes (5,27 days xenon-133 and 9,2 hours xenon-135) either released during the dissolution of the uranium irradiated samples or generated along the fission isobaric chains in the solutions of distillated iodine. In both cases the radiochemical purity of the separated products is established by gamma spectrometry. (Author) 15 refs.

Modal analysis of temperature feedback in oscillations induced by xenon

International Nuclear Information System (INIS)

Passos, E.M. dos.

1976-01-01

The flux oscillations induced by Xenon distribution in homogeneous thermal reactors are studied treating the space dependence through the modal expansion technique and the stability limits against power oscillations and spatial oscillations are determined. The effect of the feedbacks due to Xenon and temperature coefficient on the linear stability of the free system is investigated employing several number of terms in the transient expansion, considering the various sizes of the reactor. The heat transfer model considered includes one term due to cooling proportional to the temperature. A PWR model reactor is utilized for numerical calculations. It is found that a slightly higher temperature feedback coefficient is necessary for stability against power oscillations when larger number of terms in the transient modal expansion is maintained. (author)

Determining criteria for the disposal of iodine-129

International Nuclear Information System (INIS)

Burger, L.L.

1980-10-01

The basic consideration in the disposal of the 129 I produced by the nuclear power industry is that humans must be protected from unacceptable radiation risks. Existing standards prescribe maximum concentrations in air and water and, more recently, a maximum release per unit of electrical power production. The global quantity, distribution, and rate of movement of 127 I (natural iodine), naturally produced 129 I, and anthropogenic 129 I are examined. The 129 I released earlier as a result of nuclear activities over the past few decades is not uniformly dispersed. But the possibility of much greater dispersion exists and, therefore, of much greater dilution than was previously attempted. The potential for dilution with respect to either the 129 I concentration or the 129 I/ 127 I ratio far exceeds the minimum required for acceptable exposure to mankind. For utilizing the dilution principle, it is preferable to package and dispose of 129 I separately from other fission products. The deep ocean is seen to be the logical location for ultimate disposal. A set of 14 basic items is described that can be used to set criteria for storage and disposal of 129 I. It is suggested that preliminary standards be developed on these and perhaps other items to apply to (1) temporary storage and transportation, (2) disposal to a dry environment with a time limitation on calculated behavior, and (3) disposal to the deep ocean with complete release permitted in 10 3 yr. Early quantification of some of these items will permit better decisions on further research and development needed for iodine removal or control, fixation, and disposal

Imaging local cerebral blood flow by xenon-enhanced computed tomography - technical optimization procedures

Energy Technology Data Exchange (ETDEWEB)

Meyer, J.S.; Shinohara, T.; Imai, A.; Kobari, M.; Sakai, F.; Hata, T.; Oravez, W.T.; Timpe, G.M.; Deville, T.; Solomon, E.

1988-08-01

Methods are described for non-invasive, computer-assisted serial scanning throughout the human brain during eight minutes of inhalation of 27%-30% xenon gas in order to measure local cerebral blood flow (LCBF). Optimized xenon-enhanced computed tomography (XeCT) was achieved by 5-second scanning at one-minute intervals utilizing a state-of-the-art CT scanner and rapid delivery of xenon gas via a face mask. Values for local brain-blood partition coefficients (Llambda) measured in vivo were utilized to calculate LCBF values. Previous methods assumed Llambda values to be normal, introducing the risk of systematic errors, because Llambda values differ throughout normal brain and may be altered by disease. Color-coded maps of Llambda and LCBF values were formatted directly onto CT images for exact correlation of function with anatomic and pathologic observations (spatial resolution: 26.5 cubic mm). Results were compared among eight normal volunteers, aged between 50 and 88 years. Mean cortical gray matter blood flow was 46.3 +- 7.7, for subcortical gray matter it was 50.3 +- 13.2 and for white matter it was 18.8 +- 3.2. Modern CT scanners provide stability, improved signal to noise ratio and minimal radiation scatter. Combining these advantages with rapid xenon saturation of the blood provides correlations of Llambda and LCBF with images of normal and abnormal brain in a safe, useful and non-invasive manner.

Estimation of 129I inventory in the oceans

International Nuclear Information System (INIS)

Xuegao Chen; Xue Liu; Peng Yi; Zhongbo Yu; Hohai University, Nanjing; Ala Aldahan; Uppsala University, Uppsala; Li Chen; Desert Research Institute, Las Vegas, NV; Goran Possnert

2016-01-01

Spatial distribution of oceanic 129 I inventory presented here is based on collection of data from published literatures coupled with model calculation using ArcGIS software tools. A total of 363 thiessen polygons were created for the oceans in order to cover the tremendous variability in distribution of 129 I data range. The results indicate that total 129 I oceanic inventory is approximately 7310 kg, which is mainly stored in the region of the North Atlantic and the Arctic Oceans. The concentrations of 129 I in the oceans are 3-4 orders of magnitude higher than the pre-anthropogenic level reflecting effects of post 1945 anthropogenic activities. (author)

The control of the radioactive pollution of milk (1962); Comment concevoir une surveillance des pollutions radioactives du lait (1962)

Energy Technology Data Exchange (ETDEWEB)

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

1962-07-01

Milk, an essential foodstuff, is the object of a supervision and vigilant controls governed by numerous laws which protect its commercial and sanitary qualities. The development of the use of nuclear energy poses and will pose new problems of hygiene and the milk should benefit from controls concerning its possible contamination. Grass-eating animals are particularly subjected to radioactive contaminations and the milk which they produce does not escape contamination because of of its saline composition and of the particular metabolism of the mammary gland. As a result, milk is a contamination integrator and its analysis makes it possible to detect radioelements which can only be detected with great difficulty in an average size plant sample. (author) [French] Le lait, aliment essentiel, fait l'objet d'une surveillance et de controles vigilants regis par de nombreux textes legislatifs qui protegent ses qualites marchandes et sanitaires. Le developpement de l'utilisation de l'energie nucleaire pose et posera de nouveaux problemes d'hygiene et le lait doit beneficier de controles portant sur sa pollution radioactive eventuelle. Les, animaux herbivores sont particulierement exposes aux contaminations radioactives et les laits qu'ils produisent, du fait de leurs compositions salines et du metabolisme particulier de la glande mammaire, n'echappent point aux pollutions. De ce fait, le lait est un integrateur de contamination et son analyse permet de retrouver des radioelements que l'on ne decele qu'avec beaucoup de difficultes sur un echantillon vegetal de taille moyenne. (auteur)

Post-Test Inspection of Nasa's Evolutionary Xenon Thruster Long Duration Test Hardware: Ion Optics

Science.gov (United States)

Soulas, George C.; Shastry, Rohit

2016-01-01

A Long Duration Test (LDT) was initiated in June 2005 as a part of NASAs Evolutionary Xenon Thruster (NEXT) service life validation approach. Testing was voluntarily terminated in February 2014, with the thruster accumulating 51,184 hours of operation, processing 918 kg of xenon propellant, and delivering 35.5 MN-s of total impulse. This presentation will present the post-test inspection results to date for the thrusters ion optics.

Time-resolved X-ray absorption spectroscopy for laser-ablated silicon particles in xenon gas

International Nuclear Information System (INIS)

Makimura, Tetsuya; Sakuramoto, Tamaki; Murakami, Kouichi

1996-01-01

We developed a laboratory-scale in situ apparatus for soft X-ray absorption spectroscopy with a time resolution of 10 ns and a space resolution of 100 μm. Utilizing this spectrometer, we have investigated the dynamics of silicon atoms formed by laser ablation in xenon gas. It was found that 4d-electrons in the xenon atoms are excited through collision with electrons in the laser-generated silicon plasma. (author)

Theoretical aspects and experimental of neutronic interaction of multiplying media; Aspects theoriques et experimentaux de l'interaction neutronique entre milieux multiplicateurs de neutrons

Energy Technology Data Exchange (ETDEWEB)

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

1965-07-01

A theoretical study of neutronic interaction of multiplying media is presented. The use of the surface multiplication constant and of the effective multiplication constant is considered. Three classical methods of interaction calculations are studied in parallel and the application of the Keff method to problems of nuclear safety is discussed. (authors) [French] Une etude theorique de l'interaction neutronique entre milieux multiplicateurs de neutrons est presentee. L'utilisation du coefficient de multiplication de surface et du coefficient de multiplication effectif est envisagee. Trois methodes classiques de calcul d'interaction sont etudiees parallelement et l'adaptation de la methode du Keff, aux problemes de securite nucleaire est ensuite discutee. (auteurs)

Le ministre du Commerce international du Canada rencontre des ...

International Development Research Centre (IDRC) Digital Library (Canada)

17 juil. 2017 ... La promotion de l'entrepreneuriat, la façon dont le commerce peut profiter aux femmes et à leur famille, et la création d'emplois pour les plus vulnérables étaient au coeur de la discussion en table ronde du ministre du Commerce international du Canada, l'honorable François-Philippe Champagne, et des ...

Partial-wave analysis for positronium-xenon collisions in the ultralow-energy region

Science.gov (United States)

Shibuya, Kengo; Saito, Haruo

2018-05-01

We propose a method to convert measured positronium annihilation rates in gaseous xenon into total and differential cross sections of positronium-xenon collisions in an ultralow-energy region of less than 80 meV where their experimental determinations as functions of the positronium kinetic energy are extremely difficult. This method makes it possible to determine not only the s -wave collisional parameters but also the p -wave and d -wave parameters. We have found a small positive value of the scattering length, A0=2.06 ±0.10 a0 , which indicates that the positronium-xenon interaction in this energy region is repulsive and suggests that it is dominated by the scattering amplitude of the positron rather than that of the electron. An extrapolation of the analytical result into the experimentally inaccessible energy regions from 80 meV to 1.0 eV indicates that there should not be a Ramsauer-Townsend minimum but rather a peak in the total cross section at an energy of approximately 0.4 eV.

Optimisation of the measurement protocols of {sup 129}I and {sup 129}I/{sup 127}I. Methodology establishment for the measurement in environmental matrices; Optimisation des protocoles de mesurage de {sup 129}I et {sup 129}I/{sup 127}I. Etablissement d'une methodologie adaptee aux echantillons de l'environnement

Energy Technology Data Exchange (ETDEWEB)

Frechou, C

2000-07-01

{sup 129}I, is a natural long-lived isotope, with a half-life of 15,7 million years, also artificially produced in nuclear power plant. It is then released in the liquid and gaseous effluents of the nuclear fuel reprocessing plants. {sup 129}I is integrated in all biological compartments at different activity levels, depending on their distance from the emission source and their ability to metabolize iodine. Performances of the different {sup 129}I and {sup 129}I/{sup 127}I measurement techniques available: Radiochemical Neutron Activation Analysis, Accelerator Mass Spectrometry, direct {gamma}-X spectrometry and liquid scintillation were evaluated. Associated radiochemical preparation steps of the two first techniques were optimized and adapted to the characteristics of the major environmental matrices. In a first step, the radiochemical protocols were developed and validated. In a second step, intercomparison exercises have been lead on various environmental samples presenting different {sup 129}I activity levels. They showed the good agreement between the results given by the three techniques on different environmental matrices with activities between 0,2 and 200 Bq.kg{sup -1} dry weight. As a conclusion, a methodology for the measurement of {sup 129}I and {sup 129}I/{sup 127}I ratio in environmental samples is proposed. It includes a decisional diagram taking into account the characteristics of the matrices, the detection limits and the answer delay. A study on the losses of {sup 129}I during the calcination of an algae was lead by direct {gamma}-X spectrometry and application studies were made to measure {sup 129}I levels in different biological compartments issued from various locations: {sup 129}I activity interspecific variation in different species of seaweeds from the French channel coast under the relative influence of La Hague, {sup 129}I levels in bovine thyroids from the Cotentin area and {sup 129}I in vegetal samples collected around the nuclear

Migration and inventories of iodine-129 and iodine-127 in soils; Migration und Inventare von Iod-129 und Iod-127 in Boeden

Energy Technology Data Exchange (ETDEWEB)

Daraoui, A.; Michel, R.; Gorny, M.; Jakob, D.; Sachse, R. [Leibniz Univ. Hannover (Germany). Zentrum fuer Strahlenschutz und Radiooekologie; Alfimov, V.; Synal, H.A. [Eidgenoessische Technische Hochschule (ETH), Zuerich (Switzerland)

2009-07-01

Soil profiles from Bavaria in southern Germany and from Chile were analysed for {sup 129}I by accelerator mass spectrometry (AMS) and for {sup 127}I by inductively coupled plasma mass spectrometry (ICP-MS). The deposition density of {sup 129}I in the soils from Bavaria was (109 x 1.5{sup {+-}}{sup 1}) mBq m{sup -2} (geometric mean and geometric standard deviation). The dominant sources of {sup 129}I in Bavaria are the reprocessing plants La Hague and Sellafield and not the Chernobyl fallout. The {sup 129}I/{sup 127}I isotopic ratios of the Bavarian soils were measured between 10{sup -7} and 10{sup -10}, 100- to 1000-time higher than the ratios observed for the samples from Chile. The {sup 129}I integral deposition densities in Chile, Easter Island and Antarctica were between 0.3 and 2 mBq m{sup -2}. In these soils, the observed {sup 129}I/{sup 127}I ratios were about 10{sup -12}. This value is consistent with the results from the marine sediments representing the pre-nuclear equilibrium ratios. The soils from Chile allow the determination of the {sup 129}I fallout from the atmospheric nuclear weapons explosions undisturbed from contaminations due to releases from reprocessing plants. (orig.)

The behavior of xenon dynamic adsorption on granular activated carbon packed bed adsorber

International Nuclear Information System (INIS)

Chongyang Zhou; Shujuan Feng; Guoqing Zhou; Yuren Jin; Junfu Liang; Jingming Xu

2011-01-01

In order to retard radioxenon release into the atmosphere from nuclear power station or to sensitively monitor its concentration to ensure environmental and human safety, it is necessary to know the behavior of xenon dynamic adsorption on granular activated carbon pack bed adsorber. The quantities, including the dynamic adsorption coefficient (k d ), the amount of xenon adsorbed (q), the length of mass transfer zone (L MTZ ) and the length of the unused bed (LUB), used to describe the adsorption behavior, were sorted out and calculated. The factors, including xenon concentrations, pressures and temperatures, to affect these quantities were investigated. The results show that: (1) The values of k d and q decrease with increasing temperatures, but increase with increasing pressures, (2) The values of L MTZ and LUB increase with increasing temperatures or pressures, but are independent of concentrations. Knowledge of these quantities is very helpful for packed bed adsorber operation. (author)

Probe of Multielectron Dynamics in Xenon by Caustics in High-Order Harmonic Generation

Science.gov (United States)

Faccialà, D.; Pabst, S.; Bruner, B. D.; Ciriolo, A. G.; De Silvestri, S.; Devetta, M.; Negro, M.; Soifer, H.; Stagira, S.; Dudovich, N.; Vozzi, C.

2016-08-01

We investigated the giant resonance in xenon by high-order harmonic generation spectroscopy driven by a two-color field. The addition of a nonperturbative second harmonic component parallel to the driving field breaks the symmetry between neighboring subcycles resulting in the appearance of spectral caustics at two distinct cutoff energies. By controlling the phase delay between the two color components it is possible to tailor the harmonic emission in order to amplify and isolate the spectral feature of interest. In this Letter we demonstrate how this control scheme can be used to investigate the role of electron correlations that give birth to the giant resonance in xenon. The collective excitations of the giant dipole resonance in xenon combined with the spectral manipulation associated with the two-color driving field allow us to see features that are normally not accessible and to obtain a good agreement between the experimental results and the theoretical predictions.

Cerebral blood flow mapping using stable xenon-enhanced CT in sickle cell cerebrovascular disease