WorldWideScience

Sample records for partially ionised plasmas

  1. A partially ionized plasma modeling; Un modele de plasma partiellement ionise

    Energy Technology Data Exchange (ETDEWEB)

    Le Thanh, K.C.; Raviart, P.A

    2003-07-01

    We propose a model for the partially ionized plasma sheaths near the anode of an anodic spot electric arc where the cathode is considered as an electron emitter. A fluid description takes into account the heating and the ionization of the plasma induced by the electron beam. As physical hypothesis we assume that the condition of charge neutrality is valid. According that the electron mass can be neglected compared to the ion mass, we can assume that ions and atoms have the same velocity and the same temperature. Electrons and heavy particles are then regarded as two separate fluids coexisting in the plasma. Governing equations are then multi-fluid equations with relaxation correction to the local thermodynamic equilibrium (LTE) and heating by Joule effect. Equations are solved by an operator splitting procedure. That is we first discretize the homogeneous conservation laws (i.e. without source terms) by a finite volume method. The second step is to solve the ordinary differential system (i.e, governing equation without transport terms) with an implicit scheme. (authors)

  2. Critical ionisation velocity effects in astrophysical plasmas

    International Nuclear Information System (INIS)

    Raadu, M.A.

    1979-08-01

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

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

    Science.gov (United States)

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

    2016-12-01

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

  4. Ionization of anisothermal plasmas. Ionisation des plasmas polythermes

    Energy Technology Data Exchange (ETDEWEB)

    Dennery, F.M.

    1994-01-01

    During this last mid-century, only the temperature of electrons has been involved in the Saha's mass action law, whatever be the other ionic and neutral ones in any isothermal or anisothermal plasma. In order to set aside this underlying paradox in the case of argon ionization, it is necessary to improve this equation of partial equilibrium after having defined: - the basic Gibbs-Duhem's relations for such a polythermal mixture, - the inhomogeneous equilibrium issued from chemical reactions according to Le Chatelier's principle. (author). 3 refs.

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

    International Nuclear Information System (INIS)

    Morita, Shiguro; Fujita, Junji

    1985-01-01

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

  6. Physics of partially ionized plasmas

    CERN Document Server

    Krishan, Vinod

    2016-01-01

    Plasma is one of the four fundamental states of matter; the other three being solid, liquid and gas. Several components, such as molecular clouds, diffuse interstellar gas, the solar atmosphere, the Earth's ionosphere and laboratory plasmas, including fusion plasmas, constitute the partially ionized plasmas. This book discusses different aspects of partially ionized plasmas including multi-fluid description, equilibrium and types of waves. The discussion goes on to cover the reionization phase of the universe, along with a brief description of high discharge plasmas, tokomak plasmas and laser plasmas. Various elastic and inelastic collisions amongst the three particle species are also presented. In addition, the author demonstrates the novelty of partially ionized plasmas using many examples; for instance, in partially ionized plasma the magnetic induction is subjected to the ambipolar diffusion and the Hall effect, as well as the usual resistive dissipation. Also included is an observation of kinematic dynam...

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

    International Nuclear Information System (INIS)

    Raadu, M.A.

    1978-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1960-07-01

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

  9. Attenuation of acoustic waves through reflections at the plasma neutral gas interfaces: weakly ionised case

    International Nuclear Information System (INIS)

    Ghosal, S.K.; Sen, S.N.

    1977-01-01

    The problem of transmission of sonic waves through a weakly ionised plasma bounded in each side by a neutral gas medium has been treated by assuming the plasma to be a mixture of two intermingled fluids viz., neutral particle fluid and ion fluid in equilibrium. From a hydrodynamic analysis the wave equation for 'p', the macroscopic pressure perturbation has been obtained and it is shown that two independent wave motions, one due to the neutral particles and the other due to ions are propagated through the plasma with two different phase velocities. Assuming the usual boundary conditions at the interface, the amplitude of the transmitted wave has been calculated in case of weakly ionized plasma; the theory can be utilized for the determination of electron temperature from the measured value of attenuation if the percentage of ionization and collision cross section can be obtained independently. (author)

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

    International Nuclear Information System (INIS)

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

    1984-09-01

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

  11. Determination of fluspirilene in human plasma by liquid chromatography-tandem mass spectrometry with electrospray ionisation.

    Science.gov (United States)

    Swart, K J; Sutherland, F C; van Essen, G H; Hundt, H K; Hundt, A F

    1998-12-18

    An ultra-sensitive method for the determination of fluspirilene in plasma was established, using high-performance liquid chromatographic separation with tandem mass spectrometric detection. The samples were extracted with hexane/isoamyl alcohol, separated on a Phenomenex Luna C18 5 mu 150 x 2.1 mm column with a mobile phase consisting of methanol-water-acetic acid (600:400:1) at a flow-rate of 0.3 ml/min. Detection was achieved by a Finnigan Matt mass spectrometer (LCQ) at unit resolution in full scan mode scanning the product ion spectrum from m/z 130-500 and monitoring the transition of the protonated molecular ion at m/z 476.2, to the sum of the largest product ions m/z 371, 342 and 274 (MS-MS). Electrospray ionisation was used for ion production. The mean recovery for fluspirilene was 90% with a lower limit of quantification of 21.50 pg/ml using 1 ml plasma for extraction. This is the first chromatographic method described for the determination of fluspirilene in plasma that is accurate and sensitive enough to be used in pharmacokinetic studies.

  12. Simulations of Hall reconnection in partially ionized plasmas

    Science.gov (United States)

    Innocenti, Maria Elena; Jiang, Wei; Lapenta, Giovanni

    2017-04-01

    Magnetic reconnection occurs in the Hall, partially ionized regime in environments as diverse as molecular clouds, protostellar disks and regions of the solar chromosphere. While much is known about Hall reconnection in fully ionized plasmas, Hall reconnection in partially ionized plasmas is, in comparison, still relatively unexplored. This notwithstanding the fact that partial ionization is expected to affect fundamental processes in reconnection such as the transition from the slow, fluid to the fast, kinetic regime, the value of the reconnection rate and the dimensions of the diffusion regions [Malyshkin and Zweibel 2011 , Zweibel et al. 2011]. We present here the first, to our knowledge, fully kinetic simulations of Hall reconnection in partially ionized plasmas. The interaction of electrons and ions with the neutral background is realistically modelled via a Monte Carlo plug-in coded into the semi-implicit, fully kinetic code iPic3D [Markidis 2010]. We simulate a plasma with parameters compatible with the MRX experiments illustrated in Zweibel et al. 2011 and Lawrence et al. 2013, to be able to compare our simulation results with actual experiments. The gas and ion temperature is T=3 eV, the ion to electron temperature ratio is Tr=0.44, ion and electron thermal velocities are calculated accordingly resorting to a reduced mass ratio and a reduced value of the speed of light to reduce the computational costs of the simulations. The initial density of the plasma is set at n= 1.1 1014 cm-3 and is then left free to change during the simulation as a result of gas-plasma interaction. A set of simulations with initial ionisation percentage IP= 0.01, 0.1, 0.2, 0.6 is presented and compared with a reference simulation where no background gas is present (full ionization). In this first set of simulations, we assume to be able to externally control the initial relative densities of gas and plasma. Within this parameter range, the ion but not the electron population is

  13. MICROWAVE INTERACTIONS WITH INHOMOGENEOUS PARTIALLY IONIZED PLASMA

    Energy Technology Data Exchange (ETDEWEB)

    Kritz, A. H.

    1962-11-15

    Microwave interactions with inhomogeneous plasmas are often studied by employing a simplified electromagnetic approach, i.e., by representing the effects of the plasma by an effective dielectric coefficient. The problems and approximations associated with this procedure are discussed. The equation describing the microwave field in an inhomogeneous partially ionized plasma is derived, and the method that is applied to obtain the reflected, transmitted, and absorbed intensities in inhomogeneous plasmas is presented. The interactions of microwaves with plasmas having Gaussian electron density profiles are considered. The variation of collision frequency with position is usually neglected. In general, the assumption of constant collision frequency is not justified; e.g., for a highly ionized plasma, the electron density profile determines, in part, the profile of the electron-ion collision frequency. The effect of the variation of the collision frequency profile on the interaction of microwaves with inhomogeneous plasmas is studied in order to obtain an estimate of the degree of error that may result when constant collision frequency is assumed instead of a more realistic collision frequency profile. It is shown that the degree of error is of particular importance when microwave analysis is used as a plasma diagnostic. (auth)

  14. Partial local thermal equilibrium in a low-temperature hydrogen plasma

    International Nuclear Information System (INIS)

    Hey, J.D.; Chu, C.C.; Rash, J.P.S.

    1999-01-01

    If the degree of ionisation is sufficient, competition between de-excitation by electron collisions and radiative decay determines the smallest principal quantum number (the so-called 'thermal limit') above which partial local thermodynamic equilibrium (PLTE) holds under the particular conditions of electron density and temperature. The LTE (PLTE) criteria of Wilson (JQSRT 1962;2:477-90), Griem (Phys Rev 1963;131:1170-6; Plasma Spectroscopy. New York: McGraw-Hill, 1964), Drawin (Z Physik 1969;228: 99-119), Hey (JQSRT 1976;16:69-75), and Fujimoto and McWhirter (Phys Rev A 1990;42:6588-601) are examined as regards their applicability to neutral atoms. For these purposes, we consider for simplicity an idealised, steady-state, homogeneous and primarily optically thin plasma, with some additional comments and numerical estimates on the roles of opacity and of atom-atom collisions. Particularly for atomic states of lower principal quantum number, the first two of the above criteria should be modified quite appreciably before application to neutral radiators in plasmas of low temperature, because of the profoundly different nature of the near-threshold collisional cross-sections for atoms and ions, while the most recent criterion should be applied with caution to PLTE of atoms in cold plasmas in ionisation balance. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  15. Correlations in a partially degenerate electron plasma

    Energy Technology Data Exchange (ETDEWEB)

    Chihara, Junzo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    The density-functional theory proves that an ion-electron mixture can be treated as a one-component liquid interacting only via a pairwise interaction in the evaluation of the ion-ion radial distribution function (RDF), and provides a set of integral equations: one is an integral equation for the ion-ion RDF and another for an effective ion-ion interaction, which depends on the ion-ion RDF. This formulation gives a set of integral equation to calculate plasma structures with combined use of the electron-electron correlations in a partially degenerate electron plasma. Therefore, it is important for this purpose to determine the electron-electron correlations at a arbitrary temperature. Here, they are calculated by the quantal version of the hypernetted chain (HNC) equation. On the basis of the jellium-vacancy model, the ionic and electronic structures of rubidium are calculated for the range from liquid metal to plasma states by increasing the temperature at the fixed density using the electron-correlation results. (author)

  16. The specific features of self-action of high-power laser radiation propagating through a fully ionised cold plasma and the development of modulation instability

    International Nuclear Information System (INIS)

    Aleshkevich, Viktor A; Kartashev, Ya V; Vysloukh, Victor A

    2000-01-01

    The specific features of the propagation of soliton-like light beams through a fully ionised two-dimensional cold plasma are considered employing analytical and numerical methods commonly used in nonlinear optics. Exact soliton profiles for the lower and upper soliton branches are found numerically in the presence of optical bistability. It is shown that the interaction of incoherent soliton-like laser beams in such a plasma may result both in the destruction of one of the beams and in production of new ones. The regime of the modulation instability of a plane wave propagating through a cold laser-produced plasma is studied. (nonlinear optical phenomena)

  17. The effect of an alternating electric field on a totally ionised plasma

    International Nuclear Information System (INIS)

    Baglin, H.; Brin, A.; Ozias, Y.; Salmon, J.

    1960-01-01

    The equation giving the distribution function of the electrons in a steady-state, for a fully ionized plasma in an a.c. field, are provided from the Fokker-Planck equation. The electric conductivity is complex and depends on the frequency. (author) [fr

  18. Partially ionized plasmas including the third symposium on uranium plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Krishnan, M. [ed.

    1976-09-01

    Separate abstracts are included for 28 papers on electrically generated plasmas, fission generated plasmas, nuclear pumped lasers, gaseous fuel reactor research, and applications. Five papers have been previously abstracted and included in ERA.

  19. Turbulence effect on Ohm's law in partially ionized plasmas

    International Nuclear Information System (INIS)

    Numano, M.

    1977-01-01

    An investigation of the effect of nonuniformity on electric current flow in partially ionized plasmas is made. An Ohm's law for a nonuniform plasma was derived, from which Rosa's equation is obtained as a special case. Making use of this new Ohm's law, the effective electrical conductivity and Hall coefficient are determined for isotropically turbulent plasmas. They are found to be in good agreement with the results obtained previously. (author)

  20. On the evolution of a two component, two temperature, fully ionised plasma in electromagnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Oeien, A H

    1975-01-01

    When inhomogenities and fields are not too strong, transients of distribution function, correlation functions and fields which may appear when the plasma evolves from an initial state out of equilibrium are derived, applying the multiple time scale method to the BBGKY and field equations. It is also shown that, at the end of an initial stage, kinetic equations and sets of approximate field equations will govern the evolution further on. In part II a study of the evolution further on is performed when conditions are such that distribution functions to lowest order may reach local Maxwellians with different temperatures for electrons and ions. Using the same method as above, the transient behaviour into a state where macroscopic and field equations take over the leadership in the evolution is derived, and the governing equations further on, together with correcting kinetic equations, are obtained up to an order of approximation higher than before. In part III a set of lower order and a set of higher order correcting kinetic equations from part II, which correspond partly to equations for the Chapman-Enskog and the Burnett levels of approximations, are solved qualitatively. New results for various transports of a two temperature plasma are obtained.

  1. Ionising radiation

    International Nuclear Information System (INIS)

    Anon.

    1982-01-01

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

  2. Neutral Atom Diffusion in a Partially Ionized Prominence Plasma

    Science.gov (United States)

    Gilbert, Holly

    2010-01-01

    The support of solar prominences is normally described in terms of a magnetic force on the prominence plasma that balances the solar gravitational force. Because the prominence plasma is only partially ionized. it is necessary to consider in addition the support of the neutral component of the prominence plasma. This support is accomplished through a frictional interaction between the neutral and ionized components of the plasma, and its efficacy depends strongly on the degree of ionization of the plasma. More specifically, the frictional force is proportional to the relative flow of neutral and ion species, and for a sufficiently weakly ionized plasma, this flow must be relatively large to produce a frictional force that balances gravity. A large relative flow, of course, implies significant draining of neutral particles from the prominence. We evaluate the importance of this draining effect for a hydrogen-helium plasma, and consider the observational evidence for cross-field diffusion of neutral prominence material,

  3. Equation of state of partially-ionized dense plasmas

    International Nuclear Information System (INIS)

    Rogers, F.J.

    1989-01-01

    This paper describes methods for calculating the equation of state of partially-ionized dense plasmas. The term dense plasma is used rather than strongly coupled plasma, since it is possible that at plasma conditions such that only a few levels can be observed spectroscopically the plasma coupling parameters are not large. Due mainly to their importance in theoretical astrophysics, the properties of partially ionized plasmas have been of interest for a long while. More recently, this interest has intensified due to the development of methods for producing partially ionized plasmas in the laboratory. This has opened up large programs of experimental investigation and of practical application. In this paper we consider detailed statistical mechanical methods that explicitly treat the distribution over ionic species and their energy level structure. These detailed approaches are generally characterized as being in the ''chemical picture'' when a free energy expression is minimized or in the ''physical picture'' when the starting point is the grand canonical ensemble. 52 refs., 2 tabs

  4. ALFVEN WAVES IN A PARTIALLY IONIZED TWO-FLUID PLASMA

    Energy Technology Data Exchange (ETDEWEB)

    Soler, R.; Ballester, J. L.; Terradas, J. [Departament de Fisica, Universitat de les Illes Balears, E-07122 Palma de Mallorca (Spain); Carbonell, M., E-mail: roberto.soler@uib.es, E-mail: joseluis.ballester@uib.es, E-mail: jaume.terradas@uib.es, E-mail: marc.carbonell@uib.es [Departament de Matematiques i Informatica, Universitat de les Illes Balears, E-07122 Palma de Mallorca (Spain)

    2013-04-20

    Alfven waves are a particular class of magnetohydrodynamic waves relevant in many astrophysical and laboratory plasmas. In partially ionized plasmas the dynamics of Alfven waves is affected by the interaction between ionized and neutral species. Here we study Alfven waves in a partially ionized plasma from the theoretical point of view using the two-fluid description. We consider that the plasma is composed of an ion-electron fluid and a neutral fluid, which interact by means of particle collisions. To keep our investigation as general as possible, we take the neutral-ion collision frequency and the ionization degree as free parameters. First, we perform a normal mode analysis. We find the modification due to neutral-ion collisions of the wave frequencies and study the temporal and spatial attenuation of the waves. In addition, we discuss the presence of cutoff values of the wavelength that constrain the existence of oscillatory standing waves in weakly ionized plasmas. Later, we go beyond the normal mode approach and solve the initial-value problem in order to study the time-dependent evolution of the wave perturbations in the two fluids. An application to Alfven waves in the low solar atmospheric plasma is performed and the implication of partial ionization for the energy flux is discussed.

  5. Effects of Partially Ionised Medical Oxygen, Especially with O2•−, in Vibration White Finger Patients

    Directory of Open Access Journals (Sweden)

    Slavomír Perečinský

    2014-05-01

    Full Text Available A major symptom of hand-arm vibration syndrome is a secondary Raynaud’s phenomenon—vibration white finger (VWF—which results from a vasospasm of the digital arteries caused by work with vibration devices leading to occupational disease. Pharmacotherapy of VWF is often ineffective or has adverse effects. The aim of this work was to verify the influence of inhalation of partially ionized oxygen (O2•− on peripheral blood vessels in the hands of patients with VWF. Ninety one (91patients with VWF underwent four-finger adsorption plethysmography, and the pulse wave amplitude was recorded expressed in numeric parameters—called the native record. Next, a cold water test was conducted following with second plethysmography. The patients were divided in to the three groups. First and second inhaled 20-min of ionized oxygen O2•− or oxygen O2 respectively. Thirth group was control without treatment. All three groups a follow-up third plethysmography—the post-therapy record. Changes in the pulse wave amplitudes were evaluated. Inpatients group inhaling O2•− a modest increase of pulse wave amplitude was observed compared to the native record; patients inhaling medical oxygen O2 and the control showed a undesirable decline of pulse wave amplitude in VWF fingers. Strong vasodilatation were more frequent in the group inhaling O2•− compare to O2 (p < 0.05. Peripheral vasodilatation achieved by inhalation of O2•− could be used for VWF treatment without undesirable side effect in hospital as well as at home environment.

  6. MAGNETOACOUSTIC WAVES IN A PARTIALLY IONIZED TWO-FLUID PLASMA

    Energy Technology Data Exchange (ETDEWEB)

    Soler, Roberto; Ballester, Jose Luis [Departament de Física, Universitat de les Illes Balears, E-07122 Palma de Mallorca (Spain); Carbonell, Marc, E-mail: roberto.soler@uib.es, E-mail: joseluis.ballester@uib.es, E-mail: marc.carbonell@uib.es [Departament de Matemàtiques i Informàtica, Universitat de les Illes Balears, E-07122 Palma de Mallorca (Spain)

    2013-11-01

    Compressible disturbances propagate in a plasma in the form of magnetoacoustic waves driven by both gas pressure and magnetic forces. In partially ionized plasmas the dynamics of ionized and neutral species are coupled due to ion-neutral collisions. As a consequence, magnetoacoustic waves propagating through a partially ionized medium are affected by ion-neutral coupling. The degree to which the behavior of the classic waves is modified depends on the physical properties of the various species and on the relative value of the wave frequency compared to the ion-neutral collision frequency. Here, we perform a comprehensive theoretical investigation of magnetoacoustic wave propagation in a partially ionized plasma using the two-fluid formalism. We consider an extensive range of values for the collision frequency, ionization ratio, and plasma β, so that the results are applicable to a wide variety of astrophysical plasmas. We determine the modification of the wave frequencies and study the frictional damping due to ion-neutral collisions. Approximate analytic expressions for the frequencies are given in the limit case of strongly coupled ions and neutrals, while numerically obtained dispersion diagrams are provided for arbitrary collision frequencies. In addition, we discuss the presence of cutoffs in the dispersion diagrams that constrain wave propagation for certain combinations of parameters. A specific application to propagation of compressible waves in the solar chromosphere is given.

  7. MAGNETOACOUSTIC WAVES IN A PARTIALLY IONIZED TWO-FLUID PLASMA

    International Nuclear Information System (INIS)

    Soler, Roberto; Ballester, Jose Luis; Carbonell, Marc

    2013-01-01

    Compressible disturbances propagate in a plasma in the form of magnetoacoustic waves driven by both gas pressure and magnetic forces. In partially ionized plasmas the dynamics of ionized and neutral species are coupled due to ion-neutral collisions. As a consequence, magnetoacoustic waves propagating through a partially ionized medium are affected by ion-neutral coupling. The degree to which the behavior of the classic waves is modified depends on the physical properties of the various species and on the relative value of the wave frequency compared to the ion-neutral collision frequency. Here, we perform a comprehensive theoretical investigation of magnetoacoustic wave propagation in a partially ionized plasma using the two-fluid formalism. We consider an extensive range of values for the collision frequency, ionization ratio, and plasma β, so that the results are applicable to a wide variety of astrophysical plasmas. We determine the modification of the wave frequencies and study the frictional damping due to ion-neutral collisions. Approximate analytic expressions for the frequencies are given in the limit case of strongly coupled ions and neutrals, while numerically obtained dispersion diagrams are provided for arbitrary collision frequencies. In addition, we discuss the presence of cutoffs in the dispersion diagrams that constrain wave propagation for certain combinations of parameters. A specific application to propagation of compressible waves in the solar chromosphere is given

  8. Alfven wave propagation in a partially ionized plasma

    International Nuclear Information System (INIS)

    Watts, Christopher; Hanna, Jeremy

    2004-01-01

    Results from a laboratory study of the dispersion relation of Alfven waves propagating through a partially ionized plasma are presented. The plasma is generated using a helicon source, creating a high density, current-free discharge, where the source can be adjusted to one of several modes with varying neutral fraction. Depending on the neutral fraction, the measured dispersion curve of shear Alfven waves can change significantly. Measurement results are compared with theoretical predictions of the effect of neutral particles on Alfven wave propagation. In fitting the theory, the neutral fraction is independently estimated using two simple particle transport models, one collisionless, the other collisional. The two models predict comparable neutral fractions, and agree well with the neutral fraction required for the Alfven dispersion theory

  9. Nonlinear acoustic waves in partially ionized collisional plasmas

    International Nuclear Information System (INIS)

    Rao, N.N.; Kaup, D.J.; Shukla, P.K.

    1991-01-01

    Nonlinear propagation of acoustic-type waves in a partially ionized three-component collisional plasma consisting of electrons, ions and neutral particles is investigated. For bidirectional propagation, it is shown that the small- but finite-amplitude waves are governed by the Boussinesq equation, which for unidirectional propagation near the acoustic speed reduces to the usual Korteweg-de Vries equation. For large-amplitude waves, it is demonstrated that the relevant fluid equations are integrable in a stationary frame, and the parameter values for the existence of finite-amplitude solutions are explicitly obtained. In both cases, the different temperatures of the individual species, are taken into account. The relevance of the results to the earth's ionospheric plasma in the lower altitude ranges is pointed out. (author)

  10. Fluid description of multi-component solar partially ionized plasma

    International Nuclear Information System (INIS)

    Khomenko, E.; Collados, M.; Vitas, N.; Díaz, A.

    2014-01-01

    We derive self-consistent formalism for the description of multi-component partially ionized solar plasma, by means of the coupled equations for the charged and neutral components for an arbitrary number of chemical species, and the radiation field. All approximations and assumptions are carefully considered. Generalized Ohm's law is derived for the single-fluid and two-fluid formalism. Our approach is analytical with some order-of-magnitude support calculations. After general equations are developed, we particularize to some frequently considered cases as for the interaction of matter and radiation

  11. Determination of composition and physical properties of partially ionized plasmas in the function of temperature

    International Nuclear Information System (INIS)

    Zaporowski, B.

    1992-01-01

    The investigations of various kinds of partially ionized plasma were conducted for the pressure of 0.1 MPa and in the range of temperature of 298.15 K to 24000 K. The physical properties of various kinds of partially ionized plasma depend mainly of their composition and temperature. The composition of particular kinds of partially ionized plasmas varies also in the function of temperature. Simultaneous going on of physical and chemical processes in plasma is the reason of difficulties in the calculations of plasma's physical properties. The use of the laws of macroscopic thermodynamics for the calculations of physical properties of partially ionized plasma is impossible. There are enough exact methods for measuring of physical properties of partially ionized plasma. For these reasons the theoretical method using the base of statistic physics was used to calculate the composition and physical properties of various kinds of partially ionized plasma. (author) 2 refs., 2 figs

  12. Atmospheric ionisation in Snowdonia

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-06-23

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

  13. Langmuir instability in partially spin polarized bounded degenerate plasma

    Science.gov (United States)

    Iqbal, Z.; Jamil, M.; Murtaza, G.

    2018-04-01

    Some new features of waves inside the cylindrical waveguide on employing the separated spin evolution quantum hydrodynamic model are evoked. Primarily, the instability of Langmuir wave due to the electron beam in a partially spin polarized degenerate plasma considering a nano-cylindrical geometry is discussed. Besides, the evolution of a new spin-dependent wave (spin electron acoustic wave) due to electron spin polarization effects in the real wave spectrum is elaborated. Analyzing the growth rate, it is found that in the absence of Bohm potential, the electron spin effects or exchange interaction reduce the growth rate as well as k-domain but the inclusion of Bohm potential increases both the growth rate and k-domain. Further, we investigate the geometry effects expressed by R and pon and find that they have opposite effects on the growth rate and k-domain of the instability. Additionally, how the other parameters like electron beam density or streaming speed of beam electrons influence the growth rate is also investigated. This study may find its applications for the signal analysis in solid state devices at nanoscales.

  14. Collision effects on propagation characteristics of electromagnetic waves in a sub-wavelength plasma slab of partially ionized dense plasmas

    Science.gov (United States)

    Bowen, LI; Zhibin, WANG; Qiuyue, NIE; Xiaogang, WANG; Fanrong, KONG; Zhenyu, WANG

    2018-01-01

    Intensive collisions between electrons and neutral particles in partially ionized plasmas generated in atmospheric/sub-atmospheric pressure environments can sufficiently affect the propagation characteristics of electromagnetic waves, particularly in the sub-wavelength regime. To investigate the collisional effect in such plasmas, we introduce a simplified plasma slab model with a thickness on the order of the wavelength of the incident electromagnetic wave. The scattering matrix method (SMM) is applied to solve the wave equation in the plasma slab with significant nonuniformity. Results show that the collisions between the electrons and the neutral particles, as well as the incident angle and the plasma thickness, can disturb the transmission and reduce reflection significantly.

  15. Study on the electromagnetic waves propagation characteristics in partially ionized plasma slabs

    Directory of Open Access Journals (Sweden)

    Zhi-Bin Wang

    2016-05-01

    Full Text Available Propagation characteristics of electromagnetic (EM waves in partially ionized plasma slabs are studied in this paper. Such features are significant to applications in plasma antennas, blackout of re-entry flying vehicles, wave energy injection to plasmas, and etc. We in this paper developed a theoretical model of EM wave propagation perpendicular to a plasma slab with a one-dimensional density inhomogeneity along propagation direction to investigate essential characteristics of EM wave propagation in nonuniform plasmas. Particularly, the EM wave propagation in sub-wavelength plasma slabs, where the geometric optics approximation fails, is studied and in comparison with thicker slabs where the geometric optics approximation applies. The influences of both plasma and collisional frequencies, as well as the width of the plasma slab, on the EM wave propagation characteristics are discussed. The results can help the further understanding of propagation behaviours of EM waves in nonuniform plasma, and applications of the interactions between EM waves and plasmas.

  16. First observations of partially neutralized and quasineutral plasmas in the Columbia Non-neutral Torus

    Science.gov (United States)

    Sarasola, Xabier; Brenner, Paul; Hahn, Michael; Pedersen, Thomas

    2009-11-01

    The Columbia Non-neutral Torus (CNT) is the first stellarator devoted to the study of pure electron, partially neutralized and positron-electron plasmas. To date, CNT usually operates with electron rich plasmas (with negligible ion density) [1], but a stellarator can also confine plasmas of arbitrary degree of neutralization. In CNT the accumulation of ions alters the equilibrium of electron plasmas and a global instability has been observed when the ion fraction exceeds 10 %. A characterization of this instability is presented in [2], analyzing its parameter dependence and spatial structure (non- resonant with rational surfaces). A new set of experiments is currently underway studying plasmas of arbitrary degree of neutralization, ranging from pure electron to quasineutral plasmas. Basic observations show that the plasma potential decouples from emitter bias when we increase the degree of the neutralization of our plasmas. Partially neutralized plasmas are also characterized by multiple mode behavior with dominant modes between 20 and 200 kHz. When the plasma becomes quasineutral, it reverts to single mode behavior. The first results on partially neutralized plasmas confined on magnetic surfaces will be presented. [1] J. Kremer, PRL 97, (2006) 095003 [2] Q. Marksteiner, PRL 100 (2008) 065002

  17. Treatment of Partial Rotator Cuff Tear with Ultrasound-guided Platelet-rich Plasma

    Directory of Open Access Journals (Sweden)

    Vetrivel Chezian Sengodan

    2017-01-01

    Full Text Available Background: The treatment of symptomatic partial rotator cuff tear has presented substantial challenge to orthopaedic surgeons as it can vary from conservative to surgical repair. Researches have established the influence of platelet rich plasma in healing damaged tissue. Currently very few data are available regarding the evidence of clinical and radiological outcome of partial rotator cuff tear treated with ultrasound guided platelet rich plasma injection in English literature. Materials and Methods: 20 patients with symptomatic partial rotator cuff tears were treated with ultrasound guided platelet rich plasma injection. Before and after the injection of platelet rich plasma scoring was done with visual analogue score, Constant shoulder score, and UCLA shoulder score at 8 weeks and third month. A review ultrasound was performed 8 weeks after platelet rich plasma injection to assess the rotator cuff status. Results: Our study showed statistically significant improvements in 17 patients in VAS pain score, constant shoulder score and UCLA shoulder score. No significant changes in ROM were noted when matched to the contra-lateral side (P < 0.001 at the 3 month follow-up. The study also showed good healing on radiological evaluation with ultrasonogram 8 weeks after platelet rich plasma injection. Conclusion: Ultrasound guided platelet rich plasma injection for partial rotator cuff tears is an effective procedure that leads to significant decrease in pain, improvement in shoulder functions, much cost-effective and less problematic compared to a surgical treatment.

  18. On the effect of electron's runaway in partially ionized hydrogen semiclassical nonideal plasma

    International Nuclear Information System (INIS)

    Turekhanova, K.M.

    2011-01-01

    Complete text of publication follows. The effect of runaway electrons occurs frequently in tokamak plasmas. The majority of experiments in tokamak research have been devoted to the study of confinement properties of runaway electrons. Runaway electrons are reason of various destroying untolarance in tokamak plasmas. At high plasma density, when the critical energy is comparable with the rest energy the multiplication of runaway electrons accelerate at the sacrifice of increase of plasma density. The plasma conductivity is determined by electrons with energy several times higher than the thermal one and does not practically depend on slower electrons distribution. It is important to analyze the probability of runaway electrons at investigation of physical properties of nonideal plasmas under external electric field and running numerical simulations of their. The present paper is devoted to the investigation of effect of runaway electrons in partially ionized hydrogen dense plasma using the effective potentials of particle's interaction. At the investigation of composition of plasma we used the Saha equation with corrections to nonideality (lowering of ionization potentials). The Saha equation was solved for obtaining of plasma ionization stages at the different number density and temperature. As well, when take into account quantum-mechanical diffraction and screening effects, whereas free path of electrons increases with increase of plasma coupling parameter. The condition for appearance of runaway electrons in semiclassical partially ionized plasma is more favorable in regime of dense plasma. In summary it means that the probability of runaway electron in dense plasma is more than the same in rarified plasma that is possibly connected with formation of some ordered structures in dense plasma.

  19. A drift-ordered short mean-free path description of a partially ionized magnetized plasma

    International Nuclear Information System (INIS)

    Simakov, Andrei N

    2009-01-01

    Neutral particles that are present at the edge of plasma magnetic confinement devices can play an important role in energy and momentum transport, and their effects should be accounted for. This work uses the drift ordering to derive a closed fluid description for a collisional, magnetized, partially ionized plasma. Charge-exchange, ionization and recombination processes are taken into account. It is assumed that electron distribution function is unaffected by atomic processes, so that electron-ion momentum and energy exchange are described by the usual expressions for a fully ionized plasma, and that neutral-neutral collisions are unimportant. The collisional fluid equations derived herein generalize the drift-ordered description of a fully ionized collisional plasma (Catto P J et al 2004 Phys. Plasmas 11 90), agree with the MHD-ordered description of a partially ionized plasma (Helander P et al 1994 Phys. Plasmas 1 3174) in the large-flow limit and can be used to describe both turbulent and collisional behavior of a partially ionized plasma.

  20. Re-ionization of a partially ionized plasma by an Alfven wave of moderate amplitude

    International Nuclear Information System (INIS)

    Brennan, M.H.; Sawley, M.L.

    1980-01-01

    The use of forced magnetic-acoustic oscillations to investigate the effect of a torsional hydromagnetic (Alfven) wave pulse of moderate amplitude on the properties of a partially ionized afterglow helium plasma is reported. Observations of the magnetic flux associated with the oscillations, measured at a number of frequencies are used to determine radial density profiles and to provide estimates of plasma temperature. The torsional wave is shown to cause significant re-ionization of the plasma with no corresponding increase in the plasma temperature. The presence of a number of energetic particles is evidenced by the production of a significant number of doubly charged helium ions. (author)

  1. Thermal plasma treatment of stormwater sediments: comparison between DC non-transferred and partially transferred arc plasma.

    Science.gov (United States)

    Li, O L; Guo, Y; Chang, J S; Saito, N

    2015-01-01

    The disposal of enormous amount of stormwater sediments becomes an emerging worldwide problem. Stormwater sediments are contaminated by heavy metals, phosphorus, trace organic and hydrocarbons, and cannot be disposed without treatment. Thermal plasma decontamination technology offers a high decomposition rate in a wide range of toxic organic compound and immobilization of heavy metal. In this study, we compared the treatment results between two different modes of thermal plasma: (1) a non-transferred direct current (DC) mode and (2) a partial DC-transferred mode. The reductions of total organic carbon (TOC) were, respectively, 25% and 80% for non-transferred and partially transferred plasma, respectively. Most of the toxic organic compounds were converted majorly to CxHy. In the gaseous emission, the accumulated CxHy, CO, NO and H2S were significantly higher in partially transferred mode than in non-transferred mode. The solid analysis demonstrated that the concentrations of Ca and Fe were enriched by 500% and 40%, respectively. New chemical compositions such as KAlSi3O8, Fe3O4, NaCl and CaSO4 were formed after treatment in partially DC-transferred mode. The power inputs were 1 and 10 kW, respectively, for non-transferred DC mode and a partially DC-transferred mode. With a lower energy input, non-transferred plasma treatment can be used for decontamination of sediments with low TOC and metal concentration. Meanwhile, partially transferred thermal plasma with higher energy input is suitable for treating sediments with high TOC percentage and volatile metal concentration. The organic compounds are converted into valuable gaseous products which can be recycled as an energy source.

  2. Properties of partially ionized hydrogen plasmas in high electric fields

    International Nuclear Information System (INIS)

    Morawetz, K.

    1993-03-01

    In this thesis the fundamental equations of many-particle quantum-statistics of nonequilibrium are treated in respect to arbitrary high electric fields. Generalizations are found for the T-matrix approximation as well as for the shielded potential approximation valid for any field strength. These result in a non-Markovian behavior of the obtained collision integrals, also known as intra-collisional-field-effect (ICFE), and in a broadening of the energy conservation, the so-called collisional broadening (CB), caused by applied electric fields. In linear response it is shown in a new way, how the Debye-Onsager relaxation effect can be rederived from these collision integrals. Furthermore the complete quantum result is presented. Both effects, ICFE and CB, contribute to the right classical limit. The quantum result yields an surprising maximum of this field effects in dependence of the interacting mass ratio, which may be important in exciton-plasmas and semiconductors. (orig.)

  3. ALFVÉN WAVES IN A PARTIALLY IONIZED TWO-FLUID PLASMA

    International Nuclear Information System (INIS)

    Soler, R.; Ballester, J. L.; Terradas, J.; Carbonell, M.

    2013-01-01

    Alfvén waves are a particular class of magnetohydrodynamic waves relevant in many astrophysical and laboratory plasmas. In partially ionized plasmas the dynamics of Alfvén waves is affected by the interaction between ionized and neutral species. Here we study Alfvén waves in a partially ionized plasma from the theoretical point of view using the two-fluid description. We consider that the plasma is composed of an ion-electron fluid and a neutral fluid, which interact by means of particle collisions. To keep our investigation as general as possible, we take the neutral-ion collision frequency and the ionization degree as free parameters. First, we perform a normal mode analysis. We find the modification due to neutral-ion collisions of the wave frequencies and study the temporal and spatial attenuation of the waves. In addition, we discuss the presence of cutoff values of the wavelength that constrain the existence of oscillatory standing waves in weakly ionized plasmas. Later, we go beyond the normal mode approach and solve the initial-value problem in order to study the time-dependent evolution of the wave perturbations in the two fluids. An application to Alfvén waves in the low solar atmospheric plasma is performed and the implication of partial ionization for the energy flux is discussed.

  4. Generator for ionising radiation

    International Nuclear Information System (INIS)

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

    1979-01-01

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

  5. Ionising radiation. Part 2

    International Nuclear Information System (INIS)

    2000-01-01

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

  6. Influence of collective nonideal shielding on fusion reaction in partially ionized classical nonideal plasmas

    Science.gov (United States)

    Lee, Myoung-Jae; Jung, Young-Dae

    2017-04-01

    The collective nonideal effects on the nuclear fusion reaction process are investigated in partially ionized classical nonideal hydrogen plasmas. The effective pseudopotential model taking into account the collective and plasma shielding effects is applied to describe the interaction potential in nonideal plasmas. The analytic expressions of the Sommerfeld parameter, the fusion penetration factor, and the cross section for the nuclear fusion reaction in nonideal plasmas are obtained as functions of the nonideality parameter, Debye length, and relative kinetic energy. It is found that the Sommerfeld parameter is suppressed due to the influence of collective nonideal shielding. However, the collective nonideal shielding is found to enhance the fusion penetration factor in partially ionized classical nonideal plasmas. It is also found that the fusion penetration factors in nonideal plasmas represented by the pseudopotential model are always greater than those in ideal plasmas represented by the Debye-Hückel model. In addition, it is shown that the collective nonideal shielding effect on the fusion penetration factor decreases with an increase of the kinetic energy.

  7. Partial-depth modulation study of anions and neutrals in low pressure silane plasmas

    International Nuclear Information System (INIS)

    Cozurteille, C.; Dorier, J.L.; Hollenstein, C.; Sansonnens; Howling, A.A.

    1995-10-01

    Partial-depth modulation of the rf power in a capacitive discharge is used to investigate the relative importance of negative ions and neutral radicals for particle formation in low power, low pressure silane plasmas. For less than 85% modulation depth, anions are trapped indefinitely in the plasma and particle formation ensues, whereas the polymerised neutral flux magnitudes and dynamics are independent of the modulation depth and the powder formation. These observations suggest that negative ions could be the particle precursors in plasma conditions where powder appears many seconds after plasma ignition. Microwave interferometry and mass spectrometry were combined to infer an anion density of ≅7.10 9 cm -3 which is approximately twice the free electron density in these modulated plasmas. (author) 6 figs., tabs., refs

  8. Power absorption of high-frequency electromagnetic waves in a partially ionized magnetized plasma

    International Nuclear Information System (INIS)

    Guo Bin; Wang Xiaogang

    2005-01-01

    Power absorption of high-frequency electromagnetic waves in a uniformly magnetized plasma layer covering a highly conducting surface is studied under atmosphere conditions. It is assumed that the system consists of not only electrons and positive ions but negative ions as well. By a general formula derived in our previous work [B. Guo and X. G. Wang, Plasma Sci. Tech. 7, 2645 (2005)], the total power absorption in the plasma layer with multiple reflections between an air-plasma interface and the conducting surface is computed. The results show that although the existence of negative ions greatly reduces the total power absorption, the magnetization of the plasma can, however, partially enhance it. Parameter dependence of the effects is calculated and discussed

  9. Heating and ionization in MHD shock waves propagating into partially ionized plasma

    International Nuclear Information System (INIS)

    Bighel, L.; Collins, A.R.; Cramer, N.F.; Watson-Munro, C.N.

    1975-09-01

    A model of the structure of MHD switch-on shocks propagating in a partially ionized plasma, in which the primary dissipation mechanism is friction between ions and neutrals, is here compared favourably with experimental results. Four degrees of upstream ionization were studied, ranging from almost complete to very small ionization. (author)

  10. The energy balance of a plasma in partial local thermodynamic equilibrium

    NARCIS (Netherlands)

    Kroesen, G.M.W.; Schram, D.C.; Timmermans, C.J.; de Haas, J.C.M.

    1990-01-01

    The energy balance for electrons and heavy particles constituting a plasma in partial local thermodynamic equilibrium is derived. The formulation of the energy balance used allows for evaluation of the source terms without knowledge of the particle and radiation transport situation, since most of

  11. Heating and ionization in MHD shock wave propagating into partially ionized plasma

    International Nuclear Information System (INIS)

    Bighel, L.; Collins, A.R.; Cramer, N.F.; Watson-Munro, C.N.

    1975-09-01

    A model of the structure of MHD switch-on shocks propagating in a partially ionized plasma, in which the primary dissipation mechanism is friction between ions and neutrals, is here compared favourably with experimental results. Four degrees of upstream ionization were studied, ranging from almost complete to very small ionization. (author)

  12. Correlation between the plasma characteristics and the surface chemistry of plasma-treated polymers through partial least-squares analysis.

    Science.gov (United States)

    Mavadat, Maryam; Ghasemzadeh-Barvarz, Massoud; Turgeon, Stéphane; Duchesne, Carl; Laroche, Gaétan

    2013-12-23

    We investigated the effect of various plasma parameters (relative density of atomic N and H, plasma temperature, and vibrational temperature) and process conditions (pressure and H2/(N2 + H2) ratio) on the chemical composition of modified poly(tetrafluoroethylene) (PTFE). The plasma parameters were measured by means of near-infrared (NIR) and UV-visible emission spectroscopy with and without actinometry. The process conditions of the N2-H2 microwave discharges were set at various pressures ranging from 100 to 2000 mTorr and H2/(N2+H2) gas mixture ratios between 0 and 0.4. The surface chemical composition of the modified polymers was determined by X-ray photoelectron spectroscopy (XPS). A mathematical model was constructed using the partial least-squares regression algorithm to correlate the plasma information (process condition and plasma parameters as determined by emission spectroscopy) with the modified surface characteristics. To construct the model, a set of data input variables containing process conditions and plasma parameters were generated, as well as a response matrix containing the surface composition of the polymer. This model was used to predict the composition of PTFE surfaces subjected to N2-H2 plasma treatment. Contrary to what is generally accepted in the literature, the present data demonstrate that hydrogen is not directly involved in the defluorination of the surface but rather produces atomic nitrogen and/or NH radicals that are shown to be at the origin of fluorine atom removal from the polymer surface. The results show that process conditions alone do not suffice in predicting the surface chemical composition and that the plasma characteristics, which cannot be easily correlated with these conditions, should be considered. Process optimization and control would benefit from plasma diagnostics, particularly infrared emission spectroscopy.

  13. Genetic effects of ionising radiation

    International Nuclear Information System (INIS)

    Saunders, P.

    1981-01-01

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

  14. Screening of ionic cores in partially ionized plasmas within linear response

    International Nuclear Information System (INIS)

    Gericke, D. O.; Vorberger, J.; Wuensch, K.; Gregori, G.

    2010-01-01

    We employ a pseudopotential approach to investigate the screening of ionic cores in partially ionized plasmas. Here, the effect of the tightly bound electrons is condensed into an effective potential between the (free) valence electrons and the ionic cores. Even for weak electron-ion coupling, the corresponding screening clouds show strong modifications from the Debye result for elements heavier than helium. Modifications of the theoretically predicted x-ray scattering signal and implications on measurements are discussed.

  15. A consistent model for the equilibrium thermodynamic functions of partially ionized flibe plasma with Coulomb corrections

    International Nuclear Information System (INIS)

    Zaghloul, Mofreh R.

    2003-01-01

    Flibe (2LiF-BeF2) is a molten salt that has been chosen as the coolant and breeding material in many design studies of the inertial confinement fusion (ICF) chamber. Flibe plasmas are to be generated in the ICF chamber in a wide range of temperatures and densities. These plasmas are more complex than the plasma of any single chemical species. Nevertheless, the composition and thermodynamic properties of the resulting flibe plasmas are needed for the gas dynamics calculations and the determination of other design parameters in the ICF chamber. In this paper, a simple consistent model for determining the detailed plasma composition and thermodynamic functions of high-temperature, fully dissociated and partially ionized flibe gas is presented and used to calculate different thermodynamic properties of interest to fusion applications. The computed properties include the average ionization state; kinetic pressure; internal energy; specific heats; adiabatic exponent, as well as the sound speed. The presented results are computed under the assumptions of local thermodynamic equilibrium (LTE) and electro-neutrality. A criterion for the validity of the LTE assumption is presented and applied to the computed results. Other attempts in the literature are assessed with their implied inaccuracies pointed out and discussed

  16. Use of ionising radiation

    International Nuclear Information System (INIS)

    1988-11-01

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

  17. Lyapunov stability and thermal stability of partially relaxed fluids and plasmas

    International Nuclear Information System (INIS)

    Elsaesser, K.; Spiess, P.

    1996-01-01

    The relation between the Lyapunov stability of a Hamiltonian system and the thermal stability of a fluid whose temperature is controlled from outside is explored: The free energy as a functional of the correct variables (specific volume, local entropy, and some Clebsch potentials of the velocity) may serve as a Lyapunov functional, depending on the open-quote open-quote Casimirs close-quote close-quote as exchanged quantities. For a multi-species plasma one obtains a sufficient condition for stability: γ(v 2 /c 2 s )-1 s the sound speed. Some features of partially relaxed (T=const) cylindrical plasmas are also discussed. copyright 1996 American Institute of Physics

  18. Shear flow instability in a partially-ionized plasma sheath around a fast-moving vehicle

    International Nuclear Information System (INIS)

    Sotnikov, V. I.; Mudaliar, S.; Genoni, T. C.; Rose, D. V.; Oliver, B. V.; Mehlhorn, T. A.

    2011-01-01

    The stability of ion acoustic waves in a sheared-flow, partially-ionized compressible plasma sheath around a fast-moving vehicle in the upper atmosphere, is described and evaluated for different flow profiles. In a compressible plasma with shear flow, instability occurs for any velocity profile, not just for profiles with an inflection point. A second-order differential equation for the electrostatic potential of excited ion acoustic waves in the presence of electron and ion collisions with neutrals is derived and solved numerically using a shooting method with boundary conditions appropriate for a finite thickness sheath in contact with the vehicle. We consider three different velocity flow profiles and find that in all cases that neutral collisions can completely suppress the instability.

  19. Electrostatic perturbations in partially ionized plasma with the effects of ionization and recombination

    International Nuclear Information System (INIS)

    Vranjes, J.; Tanaka, M.Y.; Kono, M.; Poedts, S.

    2004-01-01

    The behavior of the electrostatic ion acoustic mode in a partially ionized plasma is studied in the presence of collisions which involve processes of ionization and recombination, taking into account the dynamics of the neutrals caused by elastic and inelastic collisions with ions. The application of the model to space plasmas, which are usually subject to gravity, is discussed in detail. A dispersion equation which includes the effects of ionization and recombination is derived and the stability/instability conditions are discussed. Parameters applicable to a region of the upper solar chromosphere are used and the increment of the ion sound wave is calculated yielding an unstable ion sound wave for wavelengths larger than 20 km

  20. Partial Variance of Increments Method in Solar Wind Observations and Plasma Simulations

    Science.gov (United States)

    Greco, A.; Matthaeus, W. H.; Perri, S.; Osman, K. T.; Servidio, S.; Wan, M.; Dmitruk, P.

    2018-02-01

    The method called "PVI" (Partial Variance of Increments) has been increasingly used in analysis of spacecraft and numerical simulation data since its inception in 2008. The purpose of the method is to study the kinematics and formation of coherent structures in space plasmas, a topic that has gained considerable attention, leading the development of identification methods, observations, and associated theoretical research based on numerical simulations. This review paper will summarize key features of the method and provide a synopsis of the main results obtained by various groups using the method. This will enable new users or those considering methods of this type to find details and background collected in one place.

  1. Radioimmunoassay of glandular kallikrein in human plasma after partial purification by immunoaffinity column

    International Nuclear Information System (INIS)

    Nishimura, Kazutaka; Inoue, Yoshikazu; Kokubu, Tatsuo

    1987-01-01

    Glandular kallikrein in human plasma was partially purified by immunoaffinity column and was measured by a radioimmunoassay (RIA). Plasma was diluted with an equal volume of 10 mmol/l sodium phosphate buffer, pH 7.4, containing 0.9% NaCl (PBS) and was applied to an immunoaffinity column from which glandular kallikrein was eluted with 3 mol/l NaSCN (20 ml). The enzymic fraction was concentrated with an Amicon PM 10 filter and dialyzed against PBS. The final recovery of the enzyme was 51.6 ± 1.6%, determined by using [ 125 I]kallikrein. The usable range of the standard curve covered 2.5-100 ng/tube. The coefficient of variation within the series was 5.9%, and the coefficient of variation between the series was 7.6%. In healthy controls, the plasma content of glandular kallikrein was 1.36 ± 0.39 ng/ml. In patients with acute pancreatitis, the plasma concentration was 8.02 ± 6.15 ng/ml, significantly different from the control group. (Auth.)

  2. Calcul de la distribution d'états de charge du néon dans un plasma coronal chaud en équilibre d'ionisation

    OpenAIRE

    BENTOTOCHE, Mohamed Sadek; MERABTI, Karim Elhadj

    2011-01-01

    L'abondance relative des di érents états de charge d'un même élément constitue l'un des paramètres les plus importants d'un plasma. La connaissance de cette abondance relative est nécessaire dans les calculs de rapports d'intensité des raies émises par di érents ions, qui peuvent servir d'outils de diagnostic des conditions physiques régnant dans le plasma émissif. Dans ce mémoire, nous avons e ectué des calculs détaillés de l'abondance relative d'ions de néon dans les six états d...

  3. Effects of finite electron temperature on gradient drift instabilities in partially magnetized plasmas

    Science.gov (United States)

    Lakhin, V. P.; Ilgisonis, V. I.; Smolyakov, A. I.; Sorokina, E. A.; Marusov, N. A.

    2018-01-01

    The gradient-drift instabilities of partially magnetized plasmas in plasma devices with crossed electric and magnetic fields are investigated in the framework of the two-fluid model with finite electron temperature in an inhomogeneous magnetic field. The finite electron Larmor radius (FLR) effects are also included via the gyroviscosity tensor taking into account the magnetic field gradient. This model correctly describes the electron dynamics for k⊥ρe>1 in the sense of Padé approximants (here, k⊥ and ρe are the wavenumber perpendicular to the magnetic field and the electron Larmor radius, respectively). The local dispersion relation for electrostatic plasma perturbations with the frequency in the range between the ion and electron cyclotron frequencies and propagating strictly perpendicular to the magnetic field is derived. The dispersion relation includes the effects of the equilibrium E ×B electron current, finite ion velocity, electron inertia, electron FLR, magnetic field gradients, and Debye length effects. The necessary and sufficient condition of stability is derived, and the stability boundary is found. It is shown that, in general, the electron inertia and FLR effects stabilize the short-wavelength perturbations. In some cases, such effects completely suppress the high-frequency short-wavelength modes so that only the long-wavelength low-frequency (with respect to the lower-hybrid frequency) modes remain unstable.

  4. Intra-ligamentary autologous conditioned plasma and healing response to treat partial ACL ruptures.

    Science.gov (United States)

    Koch, Matthias; Matteo, Berardo Di; Eichhorn, Jürgen; Zellner, Johannes; Mayr, Felix; Krutsch, Werner; Achenbach, Leonard; Woehl, Rebecca; Nerlich, Michael; Angele, Peter

    2018-05-01

    Conservative treatment of partial ACL ruptures is associated with a high failure rate, and often patients undergo ACL reconstruction. ACL preservation by trephination of the ACL origin and application of Autologous Conditioned Plasma (ACP) seems to be an intriguing new treatment option to favour ACL tissue healing and avoid traditional reconstruction. The aim of this study was to describe the mid-term outcomes of this new ACL preserving technique. Twenty-four patients (mean age 41.8 years) affected by partial rupture of one or both ACL bundles were included in the present trial. The partial ACL tears were arthroscopically assessed and classified according to a new five step grading system. All patients were treated by trephination of the femoral ACL stump and intra-ligamentary application of ACP. The postoperative outcome was evaluated by both subjective scores and stability testing up to a mean of 25.1 months' follow-up. Adverse events and failure rate were also documented. Clinical outcome was good to excellent with IKDC subjective 82.7 (SD 11.8), Lysholm 87.6 (SD 8.1), Tegner 5.3 (SD 2.1), Cincinnati 88.7 (SD 14.8). The failure rate (i.e. persisting knee instability assessed clinically or by rolimeter) was 12.5%. At objective measurements, knee joints showed a firm endpoint in Lachman test, negative pivot shift phenomenon and a significant reduction in AP-laxity compared to pre-operative status by rolimeter testing (p = 0.002). Return to sport practice was achieved after mean 4.8 months (SD 4.1). ACL stump trephination and concomitant intra-ligamentary application of ACP revealed promising results at mid-term follow-up to treat partial ACL lesions.

  5. Food ionisation. Realities and perspectives

    International Nuclear Information System (INIS)

    Bonnet, G.

    1994-06-01

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

  6. PARTIAL PURIFICATION AND IMMUNO-BIOCHEMICAL CHARACTERISATION OF FERTILITY ASSOCIATED PROTEIN OF KARAN FRIES BULL SEMINAL PLASMA

    Directory of Open Access Journals (Sweden)

    Brajesh Raman

    2014-06-01

    Full Text Available The objective of the present study was detection, isolation, partial purification and immunobiochemical characterization of fertility associated protein in the seminal plasma of high prolific Karan fries bull. Seminal plasma of Karan Fries bull was partially purified by gel filtration chromatography and analyzed by 10% SDS-PAGE for their polypeptide profile. PAGE analysis revealed major band of 55 kDa, and 26 kDa. Hyperimmune serum was raised in rabbit against crude seminal plasma protein. Single precipitin line was observed in DID test when each of the partially purified 26 kDa and 55 kDa proteins were reacted with hyperimmune serum. These proteins were also found to be immunoreactive against hyperimmune serum in Western blot technique.

  7. Dose limits for ionising radiation

    International Nuclear Information System (INIS)

    Gifford, D.

    1989-01-01

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

  8. Working safely with ionising radiation

    International Nuclear Information System (INIS)

    McDowell, D.J.

    1990-01-01

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

  9. Study of the interaction operator between two groups of particles in a completely ionised plasma. Development of the distribution functions in a series of orthogonal polynomials (1963); Etude de l'operateur d'interaction entre deux groupes de particules dans un plasma completement ionise. Developpement des fonctions de distribution en series de polynomes orthogonaux (1963)

    Energy Technology Data Exchange (ETDEWEB)

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

    1963-05-15

    A completely ionised medium is considered in which the variations of the distribution functions for each species of particles is governed by the Fokker-Planck equation. The interaction operator is of a form given by Rosenbluth - Macdonald - Judd. The distribution functions are expanded into orthogonal polynomial series in the velocity space. In a first stage these functions are first split up into spherical harmonic series (or, in an equivalent form, into series of scalar products of irreducible cartesian tensors), with coefficients which are a function of the velocity modulus as well as space and time coordinates. In the second stage these coefficients are expanded into series of orthogonal functions of the velocity modulus; the 1 order harmonic is represented by the product of a Maxwell distribution and of a SONINE polynomial series, having an index of 1 + 1 / 2, which have as variable the reduced energy of the particles (in terms of a basic temperature), with coefficients which then only depend on the space and time coordinates. In the first part the relationship is established between the expansion coefficients and the moments of the distribution function, as well as the hydrodynamic values. In the second part the expansion using spherical harmonics is applied to the Fokker-Planck equation. The general expression for the second member is given as well as the particular expressions corresponding to the cases where the operator is linearized. In the third part the complete expansion in orthogonal polynomial series is applied to the Fokker-Planck equation. The expression of the generating functions is given for all the harmonics in the case of the linearized operator, as well as the transport equations for the first four harmonics. (author) [French] On considere un milieu completement ionise ou l'evolution des fonctions de distribution pour chaque espece de particules est regie par l'equation de FOKKER-PLANCK. L'operateur d'interaction se met sous la forme

  10. Quantum effects on the formation of negative hydrogen ion by polarization electron capture in partially ionized dense hydrogen plasmas

    International Nuclear Information System (INIS)

    Jung, Young-Dae; Kato, Daiji

    2009-05-01

    The quantum effects on the formation of the negative hydrogen ion (H - ) by the polarization electron capture process are investigated in partially ionized dense hydrogen plasmas. It is shown that the quantum effect strongly suppresses the electron capture radius as well as the cross section for the formation of the negative hydrogen ion. In addition, it has been found that the electron capture position is receded from the center of the projectile with decreasing the quantum effect of the plasma. (author)

  11. The XUV spectra of highly ionised molybdenum

    International Nuclear Information System (INIS)

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

    1978-01-01

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

  12. XUV spectra of highly ionised molybdenum

    Energy Technology Data Exchange (ETDEWEB)

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

    1978-05-14

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

  13. Conversion of electromagnetic waves at the ionisation front

    International Nuclear Information System (INIS)

    Chegotov, M V

    2001-01-01

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

  14. Can laser-ionisation time-of-flight mass spectrometry be a promising alternative to laser ablation/inductively-coupled plasma mass spectrometry and glow discharge mass spectrometry for the elemental analysis of solids?

    NARCIS (Netherlands)

    Sysoev, AA; Sysoev, AA

    2002-01-01

    At the beginning of the age of laser-ionisation mass spectrometry (LIMS) increasing numbers of publications were observed. However, later the method began to run into obstacles associated with poor reproducibility of analysis and large variations in elemental sensitivities so that the wide interest

  15. Enhanced self-magnetic field by atomic polarization in partially stripped plasma produced by a short and intense laser pulse

    International Nuclear Information System (INIS)

    Hu Qianglin; Liu Shibing; Jiang, Y.J.; Zhang Jie

    2005-01-01

    The enhancement and redistribution of a self-generated quasistatic magnetic field, due to the presence of the polarization field induced by partially ionized atoms, are analytically revealed when a linearly polarized intense and short pulse laser propagates in a partially stripped plasma with higher density. In particular, the shorter wavelength of the laser pulse can evidently intensify the amplitude of the magnetic field. These enhancement and redistribution of the magnetic field are considered physically as a result of the competition of the electrostatic field (electron-ion separation) associated with the plasma wave, the atomic polarization field, and the pondoromotive potential associated with the laser field. This competition leads to the generation of a positive, large amplitude magnetic field in the zone of the pulse center, which forms a significant difference in partially and fully stripped plasmas. The numerical result shows further that the magnetic field is resonantly modulated by the plasma wave when the pulse length is the integer times the plasma wavelength. This apparently implies that the further enhancement and restructure of the large amplitude self-magnetic field can evidently impede the acceleration and stable transfer of the hot-electron beam

  16. Advisory group on ionising radiation

    International Nuclear Information System (INIS)

    Harrison, J.R.

    1996-01-01

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

  17. CHARACTERIZATION OF YTTRIA AND MAGNESIA PARTIALLY STABILIZED ZIRCONIA BIOCOMPATIBLE COATINGS DEPOSITED BY PLASMA SPRAYING

    Directory of Open Access Journals (Sweden)

    Roşu R. A.

    2013-09-01

    Full Text Available Zirconia (ZrO2 is a biocompatible ceramic material which is successfully used in medicine to cover the metallic implants by various methods. In order to avoid the inconvenients related to structural changes which may appear because of the temperature treatment while depositing the zirconia layer over the metallic implant, certain oxides are added, the most used being Y2O3, MgO and CaO. This paper presents the experimental results regarding the deposition of yttria (Y2O3 and magnesia (MgO partially stabilized zirconia layers onto titanium alloy substrate by plasma spraying method. X ray diffraction investigations carried out both on the initial powders and the coatings evidenced the fact that during the thermal spraying process the structure has not been significantly modified, consisting primarily of zirconium oxide with tetragonal structure. Electronic microscopy analyses show that the coatings are dense, uniform and cracks-free. Adherence tests performed on samples whose thickness ranges between 160 and 220 μm showed that the highest value (23.5 MPa was obtained for the coating of ZrO2 - 8 wt. % Y2O3 with 160 μm thickness. The roughness values present an increasing tendency with increasing the coatings thickness.

  18. DYNAMICS OF CORONAL RAIN AND DESCENDING PLASMA BLOBS IN SOLAR PROMINENCES. II. PARTIALLY IONIZED CASE

    Energy Technology Data Exchange (ETDEWEB)

    Oliver, R.; Soler, R.; Terradas, J. [Departament de Física, Universitat de les Illes Balears, E-07122 Palma de Mallorca (Spain); Zaqarashvili, T. V., E-mail: ramon.oliver@uib.es [Institute of Physics, IGAM, University of Graz, Universitätsplatz 5, 8010, Graz (Austria)

    2016-02-20

    Coronal rain clumps and prominence knots are dense condensations with chromospheric to transition region temperatures that fall down in the much hotter corona. Their typical speeds are in the range 30–150 km s{sup −1} and of the order of 10–30 km s{sup −1}, respectively, i.e., they are considerably smaller than free-fall velocities. These cold blobs contain a mixture of ionized and neutral material that must be dynamically coupled in order to fall together, as observed. We investigate this coupling by means of hydrodynamic simulations in which the coupling arises from the friction between ions and neutrals. The numerical simulations presented here are an extension of those of Oliver et al. to the partially ionized case. We find that, although the relative drift speed between the two species is smaller than 1 m s{sup −1} at the blob center, it is sufficient to produce the forces required to strongly couple charged particles and neutrals. The ionization degree has no discernible effect on the main results of our previous work for a fully ionized plasma: the condensation has an initial acceleration phase followed by a period with roughly constant velocity, and, in addition, the maximum descending speed is clearly correlated with the ratio of initial blob to environment density.

  19. INJECTION TO RAPID DIFFUSIVE SHOCK ACCELERATION AT PERPENDICULAR SHOCKS IN PARTIALLY IONIZED PLASMAS

    Energy Technology Data Exchange (ETDEWEB)

    Ohira, Yutaka, E-mail: ohira@phys.aoyama.ac.jp [Department of Physics and Mathematics, Aoyama Gakuin University, 5-10-1 Fuchinobe, Sagamihara 252-5258 (Japan)

    2016-08-10

    We present a three-dimensional hybrid simulation of a collisionless perpendicular shock in a partially ionized plasma for the first time. In this simulation, the shock velocity and upstream ionization fraction are v {sub sh} ≈ 1333 km s{sup −1} and f {sub i} ∼ 0.5, which are typical values for isolated young supernova remnants (SNRs) in the interstellar medium. We confirm previous two-dimensional simulation results showing that downstream hydrogen atoms leak into the upstream region and are accelerated by the pickup process in the upstream region, and large magnetic field fluctuations are generated both in the upstream and downstream regions. In addition, we find that the magnetic field fluctuations have three-dimensional structures and the leaking hydrogen atoms are injected into the diffusive shock acceleration (DSA) at the perpendicular shock after the pickup process. The observed DSA can be interpreted as shock drift acceleration with scattering. In this simulation, particles are accelerated to v ∼ 100 v {sub sh} ∼ 0.3 c within ∼100 gyroperiods. The acceleration timescale is faster than that of DSA in parallel shocks. Our simulation results suggest that SNRs can accelerate cosmic rays to 10{sup 15.5} eV (the knee) during the Sedov phase.

  20. The temporal behaviour of MHD waves in a partially ionized prominence-like plasma: Effect of heating and cooling

    Science.gov (United States)

    Ballester, J. L.; Carbonell, M.; Soler, R.; Terradas, J.

    2018-01-01

    Context. During heating or cooling processes in prominences, the plasma microscopic parameters are modified due to the change of temperature and ionization degree. Furthermore, if waves are excited on this non-stationary plasma, the changing physical conditions of the plasma also affect wave dynamics. Aims: Our aim is to study how temporal variation of temperature and microscopic plasma parameters modify the behaviour of magnetohydrodynamic (MHD) waves excited in a prominence-like hydrogen plasma. Methods: Assuming optically thin radiation, a constant external heating, the full expression of specific internal energy, and a suitable energy equation, we have derived the profiles for the temporal variation of the background temperature. We have computed the variation of the ionization degree using a Saha equation, and have linearized the single-fluid MHD equations to study the temporal behaviour of MHD waves. Results: For all the MHD waves considered, the period and damping time become time dependent. In the case of Alfvén waves, the cut-off wavenumbers also become time dependent and the attenuation rate is completely different in a cooling or heating process. In the case of slow waves, while it is difficult to distinguish the slow wave properties in a cooling partially ionized plasma from those in an almost fully ionized plasma, the period and damping time of these waves in both plasmas are completely different when the plasma is heated. The temporal behaviour of the Alfvén and fast wave is very similar in the cooling case, but in the heating case, an important difference appears that is related with the time damping. Conclusions: Our results point out important differences in the behaviour of MHD waves when the plasma is heated or cooled, and show that a correct interpretation of the observed prominence oscillations is very important in order to put accurate constraints on the physical situation of the prominence plasma under study, that is, to perform prominence

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

    NARCIS (Netherlands)

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

    2015-01-01

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

  2. Influence of easily ionised elements on the delayed responses of the emission intensities of an analyte in a power modulated U-shaped argon stabilised DC arc plasma with an aerosol supply

    Directory of Open Access Journals (Sweden)

    MIROSLAV KUZMANOVIC

    2005-09-01

    Full Text Available The current of a U-shaped argon stabilised DC arc was square modulated with a 40 Hz repetition frequency between 6 and 3 A. The delayed line intensity responses to the modulation of the arc current were investigated using calcium as a representative analyte. The intensities of both the atomic and ionic lines were monitored at different distances from the arc axis in the presence of various concentrations of the easily ionised element. Temporal evolutions were monitored on a millisecond time scale. It was found that the responses of the line intesity to the arc current change strongly depended on the observed radial position, especially in the vicinity of the arc axis. The obtained results showed a significant influence of even small amounts of the easily ionised element on the excitation and transport of the analyte and indicated a way of possibly improving the analytical capabilities of the excitation source.

  3. Diseases induced by ionising radiation

    International Nuclear Information System (INIS)

    1984-11-01

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

  4. Plasma-assisted partial oxidation of methane at low temperatures: numerical analysis of gas-phase chemical mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Goujard, Valentin; Nozaki, Tomohiro; Yuzawa, Shuhei; Okazaki, Ken [Department of Mechanical and Control Engineering, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro, 1528552, Tokyo (Japan); Agiral, Anil, E-mail: tnozaki@mech.titech.ac.jp [Mesoscale Chemical Systems, MESA Institute for Nanotechnology, Faculty of Science and Technology, University of Twente, PO Box 217, 7500 AE, Enschede (Netherlands)

    2011-07-13

    Methane partial oxidation was investigated using a plasma microreactor. The experiments were performed at 5 and 300 deg. C. Microreactor configuration allows an efficient evacuation of the heat generated by methane partial oxidation and dielectric barrier discharges, allowing at the same time a better temperature control. At 5 deg. C, liquid condensation of low vapour pressure compounds, such as formaldehyde and methanol, occurs. {sup 1}H-NMR analysis allowed us to demonstrate significant CH{sub 3}OOH formation during plasma-assisted partial oxidation of methane. Conversion and product selectivity were discussed for both temperatures. In the second part of this work, a numerical simulation was performed and a gas-phase chemical mechanism was proposed and discussed. From the comparison between the experimental results and the simulation it was found that CH{sub 3}OO{center_dot} formation has a determinant role in oxygenated compound production, since its fast formation disfavoured radical recombination. At 5 deg. C the oxidation leads mainly towards oxygenated compound formation, and plasma dissociation was the major phenomenon responsible for CH{sub 4} conversion. At 300 deg. C, higher CH{sub 4} conversion resulted from oxidative reactions induced by {center_dot}OH radicals with a chemistry predominantly oxidative, producing CO, H{sub 2}, CO{sub 2} and H{sub 2}O.

  5. Calculations on charge state and energy loss of argon ions in partially and fully ionized carbon plasmas.

    Science.gov (United States)

    Barriga-Carrasco, Manuel D; Casas, David; Morales, Roberto

    2016-03-01

    The energy loss of argon ions in a target depends on their velocity and charge density. At the energies studied in this work, it depends mostly on the free and bound electrons in the target. Here the random-phase approximation is used for analyzing free electrons at any degeneracy. For the plasma-bound electrons, an interpolation between approximations for low and high energies is applied. The Brandt-Kitagawa (BK) model is employed to depict the projectile charge space distribution, and the stripping criterion of Kreussler et al. is used to determine its equilibrium charge state Q(eq). This latter criterion implies that the equilibrium charge state depends slightly on the electron density and temperature of the plasma. On the other hand, the effective charge Q(eff) is obtained as the ratio between the energy loss of the argon ion and that of the proton for the same plasma conditions. This effective charge Q(eff) is larger than the equilibrium charge state Q(eq) due to the incorporation of the BK charge distribution. Though our charge-state estimations are not exactly the same as the experimental values, our energy loss agrees quite well with the experiments. It is noticed that the energy loss in plasmas is higher than that in the same cold target of about, ∼42-62.5% and increases with carbon plasma ionization. This confirms the well-known enhanced plasma stopping. It is also observed that only a small part of this energy loss enhancement is due to an increase of the argon charge state, namely only ∼2.2 and 5.1%, for the partially and the fully ionized plasma, respectively. The other contribution is connected with a better energy transfer to the free electrons at plasma state than to the bound electrons at solid state of about, ∼38.8-57.4%, where higher values correspond to a fully ionized carbon plasma.

  6. Beam Cooling with ionisation losses

    CERN Document Server

    Rubbia, Carlo; Kadi, Y; Vlachoudis, V

    2006-01-01

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

  7. Food preservation by ionising radiation

    International Nuclear Information System (INIS)

    Andrade, M. E.

    1996-01-01

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

  8. Nucleation in an ultra low ionisation environment

    DEFF Research Database (Denmark)

    Enghoff, Martin Andreas Bødker

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

  9. Eigenmodes of a microwave cavity partially filled with an anisotropic hot plasma

    International Nuclear Information System (INIS)

    Shoucri, M.M.; Gagne, R.R.J.

    1978-01-01

    The eigenmodes of a microwave cavity, which contains a uniform hot plasma with anisotropic temperature, are determined using the linearized fluid equations together with Maxwell's equations. Conditions are discussed under which hot plasma mode and the cold plasma mode are decoupled. The frequency shift of the microwave cavity is calculated and the theoretical results are shown to be in very good qualitative agreement with published experimental results obtained for the TM 010 mode. (author)

  10. Multi-fluid Approach to High-frequency Waves in Plasmas. II. Small-amplitude Regime in Partially Ionized Media

    Energy Technology Data Exchange (ETDEWEB)

    Martínez-Gómez, David; Soler, Roberto; Terradas, Jaume, E-mail: david.martinez@uib.es [Departament de Física, Universitat de les Illes Balears, E-07122, Palma de Mallorca (Spain)

    2017-03-01

    The presence of neutral species in a plasma has been shown to greatly affect the properties of magnetohydrodynamic waves. For instance, the interaction between ions and neutrals through momentum transfer collisions causes the damping of Alfvén waves and alters their oscillation frequency and phase speed. When the collision frequencies are larger than the frequency of the waves, single-fluid magnetohydrodynamic approximations can accurately describe the effects of partial ionization, since there is a strong coupling between the various species. However, at higher frequencies, the single-fluid models are not applicable and more complex approaches are required. Here, we use a five-fluid model with three ionized and two neutral components, which takes into consideration Hall’s current and Ohm’s diffusion in addition to the friction due to collisions between different species. We apply our model to plasmas composed of hydrogen and helium, and allow the ionization degree to be arbitrary. By analyzing the corresponding dispersion relation and numerical simulations, we study the properties of small-amplitude perturbations. We discuss the effect of momentum transfer collisions on the ion-cyclotron resonances and compare the importance of magnetic resistivity, and ion–neutral and ion–ion collisions on the wave damping at various frequency ranges. Applications to partially ionized plasmas of the solar atmosphere are performed.

  11. Plasma Catecholamines, Sweat Electrolytes and Physiological Responses of Exercised Normal, Partial Anhidrotic and Anhidrotic Horses

    OpenAIRE

    A. Bashir; A. Rasedee

    2009-01-01

    Problem statement: Malaysia imports horses from temperate countries to develop equine sports in the country. Several of these horses developed partial and complete anhidrosis. Approach: Normal, partial anhidrotic and anhidrotic horses were exercised to determine their sweating and physiological responses to exercise. The heart and respiratory rates, rectal temperature and blood samples were obtained before the horses were lunged at 10 km h-­1 for 1 h and at again at 15, 30, 45, 60 min and 24 ...

  12. Kinetic models of partially ionized complex plasmas in the low frequency regime

    International Nuclear Information System (INIS)

    Tolias, P.; Ratynskaia, S.; Angelis, U. de

    2011-01-01

    The results from three kinetic models of complex plasmas taking into account collisions with neutrals are compared in the low-frequency regime: The ''full'' model which considers the absorption of plasma fluxes on dust particles and dust charge fluctuations, the ''multi-component'' model where both these effects are neglected, and the ''standard'' model which takes into account the dust charge perturbations but not the absorption of fluxes. We derive and numerically evaluate expressions of the low frequency responses of these models, also taking into account the modification of the capture cross-sections due to the effect of neutrals. The role of plasma sources and collisions with neutrals is assessed by computing the plasma permittivities and static permittivities for all the three models.

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

    International Nuclear Information System (INIS)

    Aggarwal, S.K.

    2002-01-01

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

  14. Effects of dust-charge fluctuations on the potential of an array of projectiles in a partially ionized dusty plasma

    International Nuclear Information System (INIS)

    Ali, S.; Nasim, M.H.; Murtaza, G.

    2003-01-01

    The expressions for the Debye and the wake potential are derived by incorporating dust-charge fluctuations of a single projectile, as well as of an array of dust grain projectiles, propagating through a partially ionized dusty plasma with a constant velocity. Numerically, the effects of the dust-charge fluctuations and the dust-neutral collisions on the electrostatic potential for a single, three, six and ten projectiles are examined. The dust-charge relaxation rate modifies the shape of the Debye as well as the wake potential. For smaller values of the relaxation rates a potential well is formed instead of Debye potential

  15. MHD stabilization of high β mirror plasma partially enclosed by conducting wall

    International Nuclear Information System (INIS)

    Li, X.Z.; Kesner, J.; Lane, B.

    1985-04-01

    An MHD formulation is used to study a wall stabilized high β mirror plasma with isotropic pressure. The stabilizing wall extends axially only a part of the distance between the mirror midplane and throat. We model this arrangement using a wall that approaches the plasma surface in the bad curvature region and is distant from the plasma in the good curvature region. A variational method is used to solve the equation in the distant wall region and an iterative method is used to solve the equation when the wall is close to the plasma. A jump condition is used to connect the regions of close and distant plasma-wall proximity. A simple trial function is used to perform the variational calculation (the choice of trial function is substantiated by an exact numerical solution). The results show that for a low mirror ratio case more conducting wall surface is needed for stability than in the high mirror ratio case. This agrees with the physical mechanism of the wall stabilization

  16. Health Service use of ionising radiations: Guidance

    International Nuclear Information System (INIS)

    1995-01-01

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

  17. Ionising radiation - physical and biological effects

    International Nuclear Information System (INIS)

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

    1979-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1960-07-01

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

  19. Inactivation of Escherichia coli on blueberries using cold plasma with chemical augmentation inside a partial vacuum

    Science.gov (United States)

    Justification: The mechanism by which cold plasma inactivates pathogens is through the production of free reactive chemical species. Unfortunately, the most reactive chemical species have the shortest half-life. In a vacuum their half-life is believed to be prolonged. Additionally, these reactive sp...

  20. Calculation of gas-flow in plasma reactor for carbon partial oxidation

    Science.gov (United States)

    Bespala, Evgeny; Myshkin, Vyacheslav; Novoselov, Ivan; Pavliuk, Alexander; Makarevich, Semen; Bespala, Yuliya

    2018-03-01

    The paper discusses isotopic effects at carbon oxidation in low temperature non-equilibrium plasma at constant magnetic field. There is described routine of experiment and defined optimal parameters ensuring maximum enrichment factor at given electrophysical, gas-dynamic, and thermodymanical parameters. It has been demonstrated that at high-frequency generator capacity of 4 kW, supply frequency of 27 MHz and field density of 44 mT the concentration of paramagnetic heavy nuclei 13C in gaseous phase increases up to 1.78 % compared to 1.11 % for natural concentration. Authors explain isotopic effect decrease during plasmachemical separation induced by mixing gas flows enriched in different isotopes at the lack of product quench. With the help of modeling the motion of gas flows inside the plasma-chemical reactor based on numerical calculation of Navier-Stokes equation authors determine zones of gas mixing and cooling speed. To increase isotopic effects and proportion of 13C in gaseous phase it has been proposed to use quench in the form of Laval nozzle of refractory steel. The article represents results on calculation of optimal Laval Nozzle parameters for plasma-chemical reactor of chosen geometry of. There are also given dependences of quench time of products on pressure at the diffuser output and on critical section diameter. Authors determine the location of quench inside the plasma-chemical reactor in the paper.

  1. DAMPING OF MAGNETOHYDRODYNAMIC TURBULENCE IN PARTIALLY IONIZED PLASMA: IMPLICATIONS FOR COSMIC RAY PROPAGATION

    International Nuclear Information System (INIS)

    Xu, Siyao; Yan, Huirong; Lazarian, A.

    2016-01-01

    We study the damping processes of both incompressible and compressible magnetohydrodynamic (MHD) turbulence in a partially ionized medium. We start from the linear analysis of MHD waves, applying both single-fluid and two-fluid treatments. The damping rates derived from the linear analysis are then used in determining the damping scales of MHD turbulence. The physical connection between the damping scale of MHD turbulence and the cutoff boundary of linear MHD waves is investigated. We find two branches of slow modes propagating in ions and neutrals, respectively, below the damping scale of slow MHD turbulence, and offer a thorough discussion of their propagation and dissipation behavior. Our analytical results are shown to be applicable in a variety of partially ionized interstellar medium (ISM) phases and the solar chromosphere. The importance of neutral viscosity in damping the Alfvenic turbulence in the interstellar warm neutral medium and the solar chromosphere is demonstrated. As a significant astrophysical utility, we introduce damping effects to the propagation of cosmic rays in partially ionized ISM. The important role of turbulence damping in both transit-time damping and gyroresonance is identified.

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

    International Nuclear Information System (INIS)

    1984-01-01

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

  3. Partial purification and characterization of cysteine proteinase inhibitor from chicken plasma.

    Science.gov (United States)

    Rawdkuen, Saroat; Benjakul, Soottawat; Visessanguan, Wonnop; Lanier, Tyre C

    2006-08-01

    A high-molecular-weight cysteine proteinase inhibitor (CPI) was purified from chicken (Gallus gallus) plasma using polyethylene glycol (PEG) fractionation and affinity chromatography on carboxymethyl-papain-Sepharose-4B. The CPI was purified 96.8-fold with a yield of 28.9%. Based on inhibitory activity staining for papain, CPI was shown to have an apparent molecular mass of 122 kDa. No inhibitory activity was obtained under reducing condition, indicating that CPI from chicken plasma was stabilized by disulfide bonds. CPI was stable in temperature ranges from 40 to 70 degrees C for 10 min; however, more than 50% of the inhibitory activity towards papain was lost within 30 min of heating at 90 degrees C. CPI was stable in the presence of salt up to 3%. The purified CPI exhibited the inhibitory activity toward autolysis of arrowtooth flounder (Atheresthes stomias) and Pacific whiting (Merluccius productus) natural actomyosin (NAM) in a concentration-dependent manner.

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

    Science.gov (United States)

    Kontomaris, Stylianos-Vasileios; Malamou, Anna

    2018-01-01

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

  5. Saha and temperature relaxation approximations for the study of ionization instability in partially ionized plasma

    International Nuclear Information System (INIS)

    Numano, M.

    1976-01-01

    The growth rates for the ionization instability obtained using the Saha and temperature relaxation approximations are compared with those obtained from an exact treatment, and the requirements for validity of these two approximations are obtained analytically. For the range of plasma parameters pertinent to MHD power generation it is found that the Saha approximation is valid for relatively high electron temperature, which it becomes inapplicable as the electron temperature is decreased. On the other hand, the temperature relaxation approximation is accurate over a wide range of electron temperature. It is found also that the marginal condition for the ionization instability is correctly obtained from both approximations. (author)

  6. Noble Cantor sets acting as partial internal transport barriers in fusion plasmas

    International Nuclear Information System (INIS)

    Misguich, J.H.; Reuss, J.D.; Constantinescu, D.; Steinbrecher, G.; Vlad, M.; Spineanu, F.; Weyssow, B.; Balescu, R.

    2002-03-01

    In hot laboratory plasmas, Internal Transport Barriers (ITB) have recently been observed, localized in the radial profile 'around' rational values of the winding number ω(r)=1/q(r). Such barriers are obviously related to the perturbed magnetic structure, described by a 1+1/2 Hamiltonian in presence of a perturbation. From the point of view of non-linear Hamiltonian dynamical systems this experimental result appears highly paradoxical since rational q-values generally correspond to the less robust tori. We have studied the appearance of chaos of toroidal magnetic lines by a discrete area-preserving map named 'tokamap'. By increasing the perturbation, we have observed in a wide chaotic sea the destruction of the last confining Kolmogorov-Arnold-Moser (KAM) surfaces, broken and transformed into permeable Cantor sets (Cantori). The flux across a Cantorus has been computed by using refined mathematical techniques due to MacKay, Mather and Aubry. We have proved that the ITB observed in the tokamap is actually composed of two permeable Cantori with 'noble' values of ω (in the definition of Percival). More generally, between the dominant chains of rational islands q = m/m-1, the most resistant barriers between q = m+2/m+1 and m+1/m have been checked (Green, MacKay and Stark) to be localized on the 'most irrational' numbers in these Farey intervals, i.e. on the noble numbers N(1,m)≡ 1+[1/(m+1/G)] (where G is the Golden number) defined by their continuous fraction expansion N(i,m) = [i,m,(1) ∞ ]. In conclusion, the study of the tokamap mapping allowed us to predict on mathematical basis that ITB can occur in tokamak plasmas not only 'around' rational magnetic surfaces but more precisely on noble q-values of irrational surfaces, and to localize them by the Fibonacci series of their convergent. (authors)

  7. Impact assessment of ionising radiation in wildlife

    International Nuclear Information System (INIS)

    2001-01-01

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

  8. Impact assessment of ionising radiation on wildlife

    International Nuclear Information System (INIS)

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

    2001-01-01

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

  9. Hot corrosion behavior of plasma-sprayed partially stabilized zirconia coatings in a lithium molten salt

    International Nuclear Information System (INIS)

    Cho, Soo Haeng; Hong, Sun Seok; Kang, Dae Seong; Park, Byung Heong; Hur, Jin Mok; Lee, Han Soo

    2008-01-01

    The electrolytic reduction of spent oxide fuel involves the liberation of oxygen in a molten LiCl electrolyte, which results in a chemically aggressive environment that is too corrosive for typical structural materials. It is essential to choose the optimum material for the process equipment handling molten salt. IN713LC is one of the candidate materials proposed for application in electrolytic reduction process. In this study, Yttria-Stabilized Zirconia (YSZ) top coat was applied to a surface of IN713LC with an aluminized metallic bond coat by an optimized plasma spray process, and were investigated the corrosion behavior at 675 .deg. C for 216 hours in the molten salt LiCl-Li 2 O under an oxidizing atmosphere. The as-coated and tested specimens were examined by OM, SEM/EDS and XRD, respectively. The bare superalloy reveals obvious weight loss, and the corrosion layer formed on the surface of the bare superalloy was spalled due to the rapid scale growth and thermal stress. The top coatings showed a much better hot-corrosion resistance in the presence of LiCl-Li 2 O molten salt when compared to those of the uncoated superalloy and the aluminized bond coatings. These coatings have been found to be beneficial for increasing to the hot-corrosion resistance of the structural materials for handling high temperature lithium molten salts

  10. Collaborative Research: A Model of Partially Ionized Plasma Flows with Kinetic Treatment of Neutral Atoms and Nonthermal Ions

    International Nuclear Information System (INIS)

    Pogorelov, Nikolai; Zhang, Ming

    2016-01-01

    Interactions of flows of partially ionized, magnetized plasma are frequently accompanied by the presence of both thermal and non-thermal (pickup) ion components. Such interactions cannot be modeled using traditional MHD equations and require more advanced approaches to treat them. If a nonthermal component of ions is formed due to charge exchange and collisions between the thermal (core) ions and neutrals, it experiences the action of magnetic field, its distribution function is isotropized, and it soon acquires the velocity of the ambient plasma without being thermodynamically equilibrated. This situation, e. g., takes place in the outer heliosphere -- the part of interstellar space beyond the solar system whose properties are determined by the solar wind interaction with the local interstellar medium. This is also possible in laboratory, at million degrees and above, when plasma is conducting electricity far too well, which makes Ohmic heating ineffective. To attain the target temperatures one needs additional heating eventually playing a dominant role. Among such sources is a so-called neutral particle beam heating. This is a wide-spread technique (Joint European Torus and International Thermonuclear Experimental Reactor experiments) based on the injection of powerful beams of neutral atoms into ohmically preheated plasma. In this project we have investigated the energy and density separation between the thermal and nonthermal components in the solar wind and interstellar plasmas. A new model has been developed in which we solve the ideal MHD equations for mixture of all ions and the kinetic Boltzmann equation to describe the transport of neutral atoms. As a separate capability, we can treat the flow of neutral atoms in a multi-component fashion, where neutral atoms born in each thermodynamically distinct region are governed by the Euler gas dynamic equations. We also describe the behavior of pickup ions either kinetically, using the Fokker--Planck equation, or

  11. Collaborative Research: A Model of Partially Ionized Plasma Flows with Kinetic Treatment of Neutral Atoms and Nonthermal Ions

    Energy Technology Data Exchange (ETDEWEB)

    Pogorelov, Nikolai [Univ. of Alabama, Huntsville, AL (United States); Zhang, Ming [Florida Inst. of Technology, Melbourne, FL (United States)

    2016-07-31

    Interactions of flows of partially ionized, magnetized plasma are frequently accompanied by the presence of both thermal and non-thermal (pickup) ion components. Such interactions cannot be modeled using traditional MHD equations and require more advanced approaches to treat them. If a nonthermal component of ions is formed due to charge exchange and collisions between the thermal (core) ions and neutrals, it experiences the action of magnetic field, its distribution function is isotropized, and it soon acquires the velocity of the ambient plasma without being thermodynamically equilibrated. This situation, e. g., takes place in the outer heliosphere –- the part of interstellar space beyond the solar system whose properties are determined by the solar wind interaction with the local interstellar medium. This is also possible in laboratory, at million degrees and above, when plasma is conducting electricity far too well, which makes Ohmic heating ineffective. To attain the target temperatures one needs additional heating eventually playing a dominant role. Among such sources is a so-called neutral particle beam heating. This is a wide-spread technique (Joint European Torus and International Thermonuclear Experimental Reactor experiments) based on the injection of powerful beams of neutral atoms into ohmically preheated plasma. In this project we have investigated the energy and density separation between the thermal and nonthermal components in the solar wind and interstellar plasmas. A new model has been developed in which we solve the ideal MHD equations for mixture of all ions and the kinetic Boltzmann equation to describe the transport of neutral atoms. As a separate capability, we can treat the flow of neutral atoms in a multi-component fashion, where neutral atoms born in each thermodynamically distinct region are governed by the Euler gas dynamic equations. We also describe the behavior of pickup ions either kinetically, using the Fokker--Planck equation

  12. Collaborative Research: A Model of Partially Ionized Plasma Flows with Kinetic Treatment of Neutral Atoms and Nonthermal Ions

    Energy Technology Data Exchange (ETDEWEB)

    Pogorelov, Nikolai [Univ. of Alabama, Huntsville, AL (United States). Dept. of Space Science. Center for Space Plasma and; Zhang, Ming [Florida Inst. of Technology, Melbourne, FL (United States). Physics and Space Sciences Dept.; Borovikov, Sergey [Univ. of Alabama, Huntsville, AL (United States). Dept. of Space Science. Center for Space Plasma and Aeronomic Research; Heerikhuisen, Jacob [Univ. of Alabama, Huntsville, AL (United States). Dept. of Space Science. Center for Space Plasma and Aeronomic Research; Zank, Gary [Univ. of Alabama, Huntsville, AL (United States). Dept. of Space Science. Center for Space Plasma and Aeronomic Research; Gamayunov, Konstantin [Florida Inst. of Technology, Melbourne, FL (United States). Physics and Space Sciences Dept.; Colella, Phillip [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-07-31

    Interactions of flows of partially ionized, magnetized plasma are frequently accompanied by the presence of both thermal and non-thermal (pickup) ion components. Such interactions cannot be modeled using traditional MHD equations and require more advanced approaches to treat them. If a nonthermal component of ions is formed due to charge exchange and collisions between the thermal (core) ions and neutrals, it experiences the action of magnetic field, its distribution function is isotropized, and it soon acquires the velocity of the ambient plasma without being thermodynamically equilibrated. This situation, e. g., takes place in the outer heliosphere - the part of interstellar space beyond the solar system whose properties are determined by the solar wind interaction with the local interstellar medium. This is also possible in laboratory, at million degrees and above, when plasma is conducting electricity far too well, which makes Ohmic heating ineffective. To attain the target temperatures one needs additional heating eventually playing a dominant role. Among such sources is a so-called neutral particle beam heating. This is a wide-spread technique (Joint European Torus and International Thermonuclear Experimental Reactor experiments) based on the injection of powerful beams of neutral atoms into ohmically preheated plasma. In this project we have investigated the energy and density separation between the thermal and nonthermal components in the solar wind and interstellar plasmas. A new model has been developed in which we solve the ideal MHD equations for mixture of all ions and the kinetic Boltzmann equation to describe the transport of neutral atoms. As a separate capability, we can treat the flow of neutral atoms in a multi-component fashion, where neutral atoms born in each thermodynamically distinct regions are governed by the Euler gas dynamic equations. We also describe the behavior of pickup ions either kinetically, using the Fokker–Planck equation, or

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

    International Nuclear Information System (INIS)

    Coppee, G.H.

    1980-01-01

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

  14. [External therapy of plasma cell mastitis by jiuyi powder using partial least-squares discriminant analysis: a safety analysis].

    Science.gov (United States)

    Ye, Mei-na; Yang, Ming; Cheng, Yi-qin; Wang, Bing; Zhu, Ying; Xia, Ya-ru; Meng, Tian; Chen, Hao; Chen, Li-ying; Cheng, Hong-feng

    2015-04-01

    To evaluate the safety and the clinical value of external use of jiuyi Powder (JP) in treating plasma cell mastitis using partial least-squares discriminant analysis (PLSDA). Totally 50 patients with plasma cell mastitis treated by external use of JP were observed and biochemical examinations of blood and urine detected before application, at day 4 after application, at day 1 and 14 after discontinuation. Blood mercury and urinary mercury were detected before application, at day 1, 4, and 7 after application, at day 1 and 14 after discontinuation. Urinary mercury was also detected at 28 after discontinuation and 3 months after discontinuation. The information of wound, days of external application and the total dosage of external application were recorded before application, at day 1, 4, and 7 after application, as well as at day 1 after discontinuation. Then a discriminant model covering potential safety factors was set up by PLSDA after screening safety indices with important effects. The applicability of the model was assessed using area under ROC curve. Potential safety factors were assessed using variable importance in the projection (VIP). Urinary β2-microglobulin (β2-MG), urinary N-acetyl-β-D-glucosaminidase (NAG), 24 h urinary protein, and urinary α1-microglobulin (α1-MG) were greatly affected by external use of JP in treating plasma cell mastitis. The accuracy rate of PLSDA discriminate model was 74. 00%. The sensitivity, specificity, and the area under ROC curve was 0. 7826, 0. 7037, and 0. 8084, respectively. Three factors with greater effect on the potential safety were screened as follows: pre-application volume of the sore cavity, days of external application, and the total dosage of external application. PLSDA method could be used in analyzing bioinformation of clinical Chinese medicine. Urinary β2-MG and urinary NAG were two main safety monitoring indices. Days of external application and the total dosage of external application were main

  15. The ENEA calibration service for ionising radiations

    International Nuclear Information System (INIS)

    Monteventi, F.; Sermenghi, I.

    1999-01-01

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

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

    Science.gov (United States)

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

    2000-09-01

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

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

    International Nuclear Information System (INIS)

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

    1982-01-01

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

  18. A new thermal ionisation mass spectrometer

    International Nuclear Information System (INIS)

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

    1979-01-01

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

  19. Medical response to effects of ionising radiation

    International Nuclear Information System (INIS)

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

    1989-01-01

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

  20. Antioxidant Protection in Blood against Ionising Radiation

    International Nuclear Information System (INIS)

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

    2001-01-01

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

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

    Science.gov (United States)

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

    2015-12-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Bonnet, G

    1994-06-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Bonnet, G

    1994-06-01

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

  4. The ionisation balance of C0 to C+4

    International Nuclear Information System (INIS)

    Nussbaumer, H.; Storey, P.J.

    1975-01-01

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

  5. Ionising energy treatment of fresh fruit

    International Nuclear Information System (INIS)

    Rigney, C.J.

    1985-01-01

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

  6. The ionisation equation in a relativistic gas

    International Nuclear Information System (INIS)

    Kichenassamy, S.; Krikorian, R.A.

    1983-01-01

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

  7. Ionising radiation: a guide to the Regulations

    International Nuclear Information System (INIS)

    Hughes, Donald.

    1986-01-01

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

  8. Gas injected washer plasma gun

    International Nuclear Information System (INIS)

    Jain, K.K.; John, P.I.; Punithavelu, A.M.; Rao, P.P.

    1980-01-01

    A plasma gun similar in geometry to the washer plasma gun has been operated with gas injected externally. hydrogen, nitrogen and argon plasmas have been ionised and accelerated to velocities of the order of 10 7 mm s -1 and densities 10 11 mm -3 . Higher parameter range is possible with higher electrical input power. (author)

  9. Relationship between plasma dabigatran concentration and activated partial thromboplastin time in Japanese patients with non-valvular atrial fibrillation

    Directory of Open Access Journals (Sweden)

    Daiki Shimomura

    2015-08-01

    Conclusions: There was a significant correlation between plasma dabigatran concentrations and aPTT. Additionally, in daily clinical practice in Japan, plasma dabigatran concentrations and aPTT reached a peak in the 4-h post administration range. Considering the pharmacokinetics of dabigatran, aPTT can be used as an index for risk screening for excess dabigatran concentrations in Japanese patients with NVAF.

  10. Ionising radiation and trans-generational instability

    International Nuclear Information System (INIS)

    Vrhovac, I.; Niksic, G.

    2007-01-01

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

  11. Partial microwave-assisted wet digestion of animal tissue using a baby-bottle sterilizer for analyte determination by inductively coupled plasma optical emission spectrometry

    International Nuclear Information System (INIS)

    Matos, Wladiana O.; Menezes, Eveline A.; Gonzalez, Mario H.; Costa, Leticia M.; Trevizan, Lilian C.; Nogueira, Ana Rita A.

    2009-01-01

    A procedure for partial digestion of bovine tissue is proposed using polytetrafluoroethylene (PTFE) micro-vessels inside a baby-bottle sterilizer under microwave radiation for multi-element determination by inductively coupled plasma optical emission spectrometry (ICP OES). Samples were directly weighed in laboratory-made polytetrafluoroethylene vessels. Nitric acid and hydrogen peroxide were added to the uncovered vessels, which were positioned inside the baby-bottle sterilizer, containing 500 mL of water. The hydrogen peroxide volume was fixed at 100 μL. The system was placed in a domestic microwave oven and partial digestion was carried out for the determination of Ca, Cu, Fe, Mg, Mn and Zn by inductively coupled plasma optical emission spectrometry. The single-vessel approach was used in the entire procedure, to minimize contamination in trace analysis. Better recoveries and lower residual carbon content (RCC) levels were obtained under the conditions established through a 2 4-1 fractional factorial design: 650 W microwave power, 7 min digestion time, 50 μL nitric acid and 50 mg sample mass. The digestion efficiency was ascertained according to the residual carbon content determined by inductively coupled plasma optical emission spectrometry. The accuracy of the proposed procedure was checked against two certified reference materials.

  12. Plasmas pour valorisation totale ou partielle des gaz contenant de l'H2S Plasmas for Total Or Partial Upgrading of H2s Containing Gases

    Directory of Open Access Journals (Sweden)

    Czernichowski A.

    2006-12-01

    Full Text Available Des procédés par plasmas alternatifs au procédé Claus sont proposés pour produire de l'hydrogène et récupérer du soufre à partir des gaz contenant une forte teneur en H2S. Quand la teneur en H2S est moins importante, des techniques plasma peuvent également être utiles pour assister certains étages du procédé classique Claus ou réaliser ce procédé pour des gaz non conventionnels. Les tests allant jusqu'à l'échelle industrielle sont menés dans divers réacteurs à plasmas et les résultats encourageants rapportés de la littérature et de la recherche propre laissent envisager des prochaines applications. Plasma assisted processes are proposed to act as an alternative to the Claus process in order to recover hydrogen and sulphur from high H2S gases. For less concentrated gases plasma techniques may also be inserted into classical Claus plant or may allow treatment of non conventional gases. Up to industrial scale tests are performed using different plasma reactors. The literature-based results as well as our own ones make the future applications quite optimistic.

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

    International Nuclear Information System (INIS)

    Reeves, V.

    2003-01-01

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

  14. Exotic highly ionising particles at the LHC

    CERN Document Server

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

    2012-01-01

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

  15. Effects of intense stratospheric ionisation events

    International Nuclear Information System (INIS)

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

    1978-01-01

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

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

    International Nuclear Information System (INIS)

    Vidal, J.P.

    1998-01-01

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

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

    International Nuclear Information System (INIS)

    Duinker, W.

    1981-01-01

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

  18. Effect of plasma fluorination variables on the deposition and growth of partially fluorinated polymer over PMMA films

    Directory of Open Access Journals (Sweden)

    Giovana da Silva Padilha

    2013-01-01

    Full Text Available In this work, an investigation was made of the modification of film surface of Poly(methylmethacrylate (PMMA using the plasma polymerization technique. PMMA films 10 µm thick were obtained by Spin-Coating starting from a chloroform solution (15.36% w/w. The films were exposed to the plasma of CHF3 at different gas pressures and exposure times to increase the thickness of fluorinated polymers onto PMMA films. The plasma fluorinated optical films were characterized by gravimetry, FTIR-ATR, contact angle of wetting, SEM and AFM. The surface fluorination of PMMA films can be inferred by the increase in contact angle under all experimental conditions, and confirmed with FTIR-ATR analysis. Gravimetry showed an increase of the fluorinated polymer layer over PMMA films, being 1.55 µm thick at 0.7 torr and 40 minutes of plasma exposure. The SEM analysis showed a well-defined layer of fluorinated polymer, with fluorine being detected in the EDS analysis. The film roughness for the fluorinated polymers was around of 200 Å, quite satisfactory for a 1.55 µm cladding.

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

    International Nuclear Information System (INIS)

    1989-12-01

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

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

    International Nuclear Information System (INIS)

    1989-01-01

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

  1. Sensitivity of the activated partial thromboplastin time, the dilute Russell's viper venom time, and the kaolin clotting time for the detection of the lupus anticoagulant: a direct comparison using plasma dilutions.

    Science.gov (United States)

    Martin, B A; Branch, D W; Rodgers, G M

    1996-01-01

    Increasing dilutions of lupus anticoagulant (LA) plasmas from twelve patients were used to directly compare the sensitivity of four tests for LA. The tests evaluated were the modified Bell and Alton activated partial thromboplastin time (APTT), an APTT using a commercially prepared partial thromboplastin (Platelin LS APTT), a modified dilute Russell's viper venom time (DRVVT), and a modified kaolin clotting time (KCT). LAs were detected in all twelve plasmas by each of three tests and eleven of twelve plasmas in a fourth test when undiluted patient plasma was used. Repeating the tests after diluting the LA plasmas with normal platelet-free plasma (PFP) showed that the KCT was the most sensitive test for LA, detecting eleven of twelve LAs at a dilution of 10% patient plasma and ten of twelve LAs at a dilution of 5% patient plasma. The modified Bell and Alton APTT and the modified DRVVT had similar sensitivities at a patient plasma concentration of 10%, detecting seven of twelve and eight of twelve LAs, respectively. The Platelin LS APTT detected only four of twelve LAs at a patient plasma concentration of 10%. Our results indicate that the modified KCT is a sensitive method for the detection of LAs. The modified Bell and Alton APTT and the DRVVT were less sensitive.

  2. Effects of small doses of ionising radiation

    International Nuclear Information System (INIS)

    Doll, R.

    1998-01-01

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

  3. Influence of partially-stripped impurity ions on the cyclotron absorption of the fast magnetosonic wave in TFR plasmas

    International Nuclear Information System (INIS)

    1985-11-01

    Injection of vanadium ions by the laser blow-off technique has permitted to modify at will the impurity content in TFR plasmas prior to ion-cyclotron resonance (ICR) heating experiments in the mode conversion regime. The initial rate of increase of the central deuteron temperature has thus been enhanced. By solving the wave propagation equation in the WKB approximation, it has been possible to account for the enhanced dTsub(D)(O)/dt value by wave energy deposition on resonating V 21+ ions, provided a fraction (of the order of 1O%) of these ions has been accelerated to the tens of keV range. Previous experimental ICR heating results, in conditions such that the proton cyclotron layer is outside the limiter radius, can be explained by similar resonance processes on intrinsic metal impurity ions

  4. Partial cranial cruciate ligament tears treated with stem cell and platelet rich plasma combination therapy in 36 dogs: a retrospective study

    Directory of Open Access Journals (Sweden)

    Sherman Canapp

    2016-12-01

    Full Text Available Objective: To evaluate outcomes in 36 dogs with a partial CCL tear treated with autologous bone marrow aspirate concentrate (BMAC or adipose derived progenitor cells (ADPC with platelet rich plasma (PRP combination.Materials and Methods: Medical records of client-owned dogs diagnosed with an early partial (≤50% tear of the craniomedial band of the CCL that were treated with BMAC-PRP or ADPC-PRP were reviewed from 2010-2015. Signalment, medical history, physical and orthopedic examination, objective temporospatial gait analyses, radiographs, day 0 and day 90 diagnostic arthroscopy findings, treatment, and outcome were among the data collected. A functional owner questionnaire, including the validated Helsinki chronic pain index (HCPI, was sent to owners whose dog was known to not have had a TPLO. Statistical analysis was performed on data, where significance was established at p50% CCL tear and a TPLO was performed. Four additional dogs were known to have had a TPLO performed elsewhere. Baseline and day 90 post treatment objective gait analyses were available on 11 of the 36 dogs. A significant difference was found between the treated limb TPI% at day 0 and day 90 (p=0.0124, and between the treated limb and contralateral limb TPI% at day 0 (p=0.0003. No significant difference was found between the treated limb and contralateral limb TPI% at day 90 (p=0.7466. Twelve questionnaires were returned, of which 8 were performance/sporting dogs. Seven of the 8 had returned to sport; the remaining dog had just begun a return to sport conditioning program 6 months post treatment. All 12 respondents believed their dog had an excellent or very good quality of life, and rated their dog’s procedural outcome as excellent or good.Conclusion: The use of BMAC-PRP and ADPC-PRP shows promise for the treatment of early partial CCL tears in dogs.

  5. Tailoring nanomaterial products through electrode material and oxygen partial pressure in a mini-arc plasma reactor

    International Nuclear Information System (INIS)

    Cui Shumao; Mattson, Eric C.; Lu, Ganhua; Hirschmugl, Carol; Gajdardziska-Josifovska, Marija; Chen Junhong

    2012-01-01

    Nanomaterials with controllable morphology and composition are synthesized by a simple one-step vapor condensation process using a mini-arc plasma source. Through systematic investigation of mini-arc reactor parameters, the roles of carrier gas, electrode material, and precursor on producing diverse nanomaterial products are revealed. Desired nanomaterial products, including tungsten oxide nanoparticles (NPs), tungsten oxide nanorods (NRs), tungsten oxide and tin oxide NP mixtures and pure tin dioxide NPs can thus be obtained by tailoring reaction conditions. The amount of oxygen in the reactor is critical to determining the final nanomaterial product. Without any precursor material present, a lower level of oxygen in the reactor favors the production of W 18 O 49 NRs with tungsten as cathode, while a high level of oxygen produces more round WO 3 NPs. With the presence of a precursor material, amorphous particles are favored with a high ratio of argon:oxygen. Oxygen is also found to affect tin oxide crystallization from its amorphous phase in the thermal annealing. Results from this study can be used for guiding gas phase nanomaterial synthesis in the future.

  6. Introducing Biological Microdosimetry for Ionising Radiation

    International Nuclear Information System (INIS)

    Scott, B.R.; Schoellnberger, H.

    2000-01-01

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

  7. Introducing Biological Microdosimetry for Ionising Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Scott, B.R.; Schoellnberger, H

    2000-07-01

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

  8. Nanoscale photoelectron ionisation detector based on lanthanum hexaboride

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  9. Threshold law for positron-atom impact ionisation

    International Nuclear Information System (INIS)

    Temkin, A.

    1982-01-01

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

  10. Ionisation Chambers for the LHC Beam Loss Detection

    CERN Document Server

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

    2003-01-01

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

  11. Ionisation detectors as monitors of toxic compounds in air

    International Nuclear Information System (INIS)

    Leonhardt, J.W.

    1994-01-01

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

  12. Ionised gas kinematics in bipolar H II regions

    Science.gov (United States)

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

    2018-05-01

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

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

    Science.gov (United States)

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

    2018-01-01

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

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

    Science.gov (United States)

    Farina, D.

    2018-06-01

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

  15. On the Experimental and Theoretical Investigations of Lean Partially Premixed Combustion, Burning Speed, Flame Instability and Plasma Formation of Alternative Fuels at High Temperatures and Pressures

    Science.gov (United States)

    Askari, Omid

    This dissertation investigates the combustion and injection fundamental characteristics of different alternative fuels both experimentally and theoretically. The subjects such as lean partially premixed combustion of methane/hydrogen/air/diluent, methane high pressure direct-injection, thermal plasma formation, thermodynamic properties of hydrocarbon/air mixtures at high temperatures, laminar flames and flame morphology of synthetic gas (syngas) and Gas-to-Liquid (GTL) fuels were extensively studied in this work. These subjects will be summarized in three following paragraphs. The fundamentals of spray and partially premixed combustion characteristics of directly injected methane in a constant volume combustion chamber have been experimentally studied. The injected fuel jet generates turbulence in the vessel and forms a turbulent heterogeneous fuel-air mixture in the vessel, similar to that in a Compressed Natural Gas (CNG) Direct-Injection (DI) engines. The effect of different characteristics parameters such as spark delay time, stratification ratio, turbulence intensity, fuel injection pressure, chamber pressure, chamber temperature, Exhaust Gas recirculation (EGR) addition, hydrogen addition and equivalence ratio on flame propagation and emission concentrations were analyzed. As a part of this work and for the purpose of control and calibration of high pressure injector, spray development and characteristics including spray tip penetration, spray cone angle and overall equivalence ratio were evaluated under a wide range of fuel injection pressures of 30 to 90 atm and different chamber pressures of 1 to 5 atm. Thermodynamic properties of hydrocarbon/air plasma mixtures at ultra-high temperatures must be precisely calculated due to important influence on the flame kernel formation and propagation in combusting flows and spark discharge applications. A new algorithm based on the statistical thermodynamics was developed to calculate the ultra-high temperature plasma

  16. Bifurcations of solitary wave solutions for (two and three)-dimensional nonlinear partial differential equation in quantum and magnetized plasma by using two different methods

    Science.gov (United States)

    Khater, Mostafa M. A.; Seadawy, Aly R.; Lu, Dianchen

    2018-06-01

    In this research, we study new two techniques that called the extended simple equation method and the novel (G‧/G) -expansion method. The extended simple equation method depend on the auxiliary equation (dϕ/dξ = α + λϕ + μϕ2) which has three ways for solving depends on the specific condition on the parameters as follow: When (λ = 0) this auxiliary equation reduces to Riccati equation, when (α = 0) this auxiliary equation reduces to Bernoulli equation and when (α ≠ 0, λ ≠ 0, μ ≠ 0) we the general solutions of this auxiliary equation while the novel (G‧/G) -expansion method depends also on similar auxiliary equation (G‧/G)‧ = μ + λ(G‧/G) + (v - 1)(G‧/G) 2 which depend also on the value of (λ2 - 4 (v - 1) μ) and the specific condition on the parameters as follow: When (λ = 0) this auxiliary equation reduces to Riccati equation, when (μ = 0) this auxiliary equation reduces to Bernoulli equation and when (λ2 ≠ 4 (v - 1) μ) we the general solutions of this auxiliary equation. This show how both of these auxiliary equation are special cases of Riccati equation. We apply these methods on two dimensional nonlinear Kadomtsev-Petviashvili Burgers equation in quantum plasma and three-dimensional nonlinear modified Zakharov-Kuznetsov equation of ion-acoustic waves in a magnetized plasma. We obtain the exact traveling wave solutions of these important models and under special condition on the parameters, we get solitary traveling wave solutions. All calculations in this study have been established and verified back with the aid of the Maple package program. The executed method is powerful, effective and straightforward for solving nonlinear partial differential equations to obtain more and new solutions.

  17. Hardening by means of ionising radiation

    International Nuclear Information System (INIS)

    Spoor, H.; Demmler, K.

    1979-01-01

    The polymerisable ethylic unsaturated mixture can be hardened by means of electron irradiation and used as a corrosion preventive layer. The mixture mainly consists of at least a di-olefinic unsaturated polyester, partial esters of polycarbonic acids, in particular the monoester of dicarbonic acids, with a copolymerizable C-C double bond, and mono-olefine unsaturated hydrocarbons, for example vinyl aromatics. The coatings exhibit good adhesion to the substrate, in particular to metal, and good flexibility. (DG) [de

  18. The case against protecting the environment from ionising radiation

    International Nuclear Information System (INIS)

    Smith, J.T.

    2004-01-01

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

  19. Cost considerations for an ionising energy treatment facility

    International Nuclear Information System (INIS)

    Culpitt, R.A.

    1985-01-01

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

  20. NDT using ionising radiation in the Indian space programme

    International Nuclear Information System (INIS)

    Viswanathan, K.

    1997-01-01

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

  1. Determination of iodine at ppt level in a nitric acid medium by inductively coupled plasma sector field mass spectrometry: influence of the chemical forms; Etude de la determination de traces d'iode en solution par spectrometrie de masse a secteur magnetique utilisant un plasma a couplage inductif comme source d'ionisation: influence de la forme chimique

    Energy Technology Data Exchange (ETDEWEB)

    Langlois, B

    2001-07-01

    Inductively Coupled Plasma Sector Field Mass Spectrometry (ICP/SFMS) was used to determine several chemical forms of iodine, at ppt level, in a nitric acid media. Ascorbic acid was added as a reducing agent in order to maintain iodine as iodide. In a preliminary approach, the influence of the chemical form was studied by comparing inorganic iodine (NaI) and organic iodine (CH3I). Different signal responses were observed. With a conventional sample introduction system, sensitivities obtained for iodo-methane could differ by a factor of 5. This was not caused by a problem of atomization or by a change in the ionization efficiency of the iodo-compound into the plasma. The low volatilization temperature of iodo-methane (315.5 K) seemed to be the main explanation of this phenomena. Actually, nebulization resulted in the volatilization of a 2% nitric acid solution containing iodo-methane. As a result, the transport efficiency of iodo-methane between the nebulizer and the torch was approaching 100%. A Direct Injection High Efficiency Nebulizer (DIHEN) allowed us to minimize the behavior difference between the two iodine species, but the sensitivity ratio was inverted and still differed by 20 - 40%. Moreover, the association of a guard electrode and the direct injection system was studied in order to apply these equipments to the determination of iodine. This association allowed us to improve the sensitivity by a factor of 10 and to minimize memory effects, when compared with a conventional system. Further studies indicated that signal responses obtained with different iodine-containing species, except for iodo-methane, were found to be similar. (author)

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

    International Nuclear Information System (INIS)

    Ford, M.J.

    1998-01-01

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

  3. Interaction of ionising radiations with matter

    International Nuclear Information System (INIS)

    Caudrelier, Olivier

    2010-01-01

    In a first part, this academic course addresses the interaction of non-charged particles with matter. The author more particularly addresses the interaction of a photon plasma with matter (attenuation of electromagnetic radiations, law of exponential attenuation, attenuation half value layer), the elementary phenomena of the interaction of a photon with matter (photoelectric effect, Compton effect, Thomson-Rayleigh scattering, materialisation, photo-nuclear reaction, prevalence domains, application in medical imagery), and the interaction of fast and slow neutrons with matter (elastic and inelastic scattering, radiative and non-radiative capture). The second part addresses the interaction of charged particles with matter. The author more particularly addresses the interaction with electrons present in the medium (ionization, excitation, stop efficiency, linear energy transfer, ionization linear density), the interaction with the nucleus (Bremsstrahlung), and the case of light particles (electrons) and of heavy particles (protons, alpha, fission products)

  4. Non-linear phenomena in ionised media

    International Nuclear Information System (INIS)

    Oprescu, B.; Anghel, S.

    2004-01-01

    The aim of the present paper is to show, on experimental bases, that the occurrence of the microwaves in a plasma device is preceded by the formation of an unstable double layer, which, by exciting an ion-acoustic wave in the ionized gas column, permits the modulations of the electron speed within a beam of fast electrons crossing the gas. The starting point used in achieving this device was the following: to create an ionized medium (which can be obtained through the agency of the cylindrical cathode) in which a fast electron beam is injected at the same time as an unstable double layer form. Such a cathode capable of meeting the two conditions was first developed by G. G. Bratescu, D. Ciobotaru and G. Dima, namely, the cathode in semi-closed geometry. The experiments were carried out in water vapors under low pressure. (authors)

  5. Extra holiday because of ionising radiation not necessary

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

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

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

    International Nuclear Information System (INIS)

    Leitz, W.

    2003-01-01

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

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

    International Nuclear Information System (INIS)

    Moore, P.W.

    1985-01-01

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

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

    CERN Document Server

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

    2002-01-01

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

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

    International Nuclear Information System (INIS)

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

    1998-01-01

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

  10. Erich Regener and the ionisation maximum of the atmosphere

    Science.gov (United States)

    Carlson, P.; Watson, A. A.

    2014-12-01

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

  11. IRID: specifications for the Ionising Radiations Incident Database

    International Nuclear Information System (INIS)

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

    1996-01-01

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

  12. Complex systems of biological interest stability under ionising radiations

    International Nuclear Information System (INIS)

    Maclot, Sylvain

    2014-01-01

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

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

    International Nuclear Information System (INIS)

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

    1998-01-01

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

  14. 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)

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

    International Nuclear Information System (INIS)

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

    2004-01-01

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

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

    Science.gov (United States)

    2018-01-01

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

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

    International Nuclear Information System (INIS)

    Wang De-Hua

    2011-01-01

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

  18. Partial baroreceptor dysfunction and low plasma nitric oxide bioavailability as determinants of salt-sensitive hypertension: a reverse translational rat study

    Energy Technology Data Exchange (ETDEWEB)

    Rodríguez-Pérez, A.S.; López-Rodríguez, J.F.; Calvo-Turrubiartes, M.Z. [Integrative Physiology Laboratory, Department of Physiology and Biophysics, San Luis Potosí (Mexico); Saavedra-Alanís, V.M. [Molecular Biology Laboratory, Department of Biochemistry, San Luis Potosí (Mexico); Llamazares-Azuara, L. [Autonomous University of San Luis Potosí, Renal Laboratory, Faculty of Medicine, San Luis Potosí (Mexico); Rodríguez-Martínez, M. [Integrative Physiology Laboratory, Department of Physiology and Biophysics, San Luis Potosí (Mexico)

    2013-10-02

    This study determined whether clinical salt-sensitive hypertension (cSSHT) results from the interaction between partial arterial baroreceptor impairment and a high-sodium (HNa) diet. In three series (S-I, S-II, S-III), mean arterial pressure (MAP) of conscious male Wistar ChR003 rats was measured once before (pdMAP) and twice after either sham (SHM) or bilateral aortic denervation (AD), following 7 days on a low-sodium (LNa) diet (LNaMAP) and then 21 days on a HNa diet (HNaMAP). The roles of plasma nitric oxide bioavailability (pNOB), renal medullary superoxide anion production (RMSAP), and mRNA expression of NAD(P)H oxidase and superoxide dismutase were also assessed. In SHM (n=11) and AD (n=15) groups of S-I, LNaMAP-pdMAP was 10.5±2.1 vs 23±2.1 mmHg (P<0.001), and the salt-sensitivity index (SSi; HNaMAP−LNaMAP) was 6.0±1.9 vs 12.7±1.9 mmHg (P=0.03), respectively. In the SHM group, all rats were normotensive, and 36% were salt sensitive (SSi≥10 mmHg), whereas in the AD group ∼50% showed cSSHT. A 45% reduction in pNOB (P≤0.004) was observed in both groups in dietary transit. RMSAP increased in the AD group on both diets but more so on the HNa diet (S-II, P<0.03) than on the LNa diet (S-III, P<0.04). MAP modeling in rats without a renal hypertensive genotype indicated that the AD*HNa diet interaction (P=0.008) increases the likelihood of developing cSSHT. Translationally, these findings help to explain why subjects with clinical salt-sensitive normotension may transition to cSSHT.

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

    International Nuclear Information System (INIS)

    Raj, Baldev; Venkatraman, B.

    1988-02-01

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

  20. Excitation of low-frequency residual currents at combination frequencies of an ionising two-colour laser pulse

    Science.gov (United States)

    Vvedenskii, N. V.; Kostin, V. A.; Laryushin, I. D.; Silaev, A. A.

    2016-05-01

    We have studied the processes of excitation of low-frequency residual currents in a plasma produced through ionisation of gases by two-colour laser pulses in laser-plasma schemes for THz generation. We have developed an analytical approach that allows one to find residual currents in the case when one of the components of a two-colour pulse is weak enough. The derived analytical expressions show that the effective generation of the residual current (and hence the effective THz generation) is possible if the ratio of the frequencies in the two-colour laser pulse is close to a rational fraction with a not very big odd sum of the numerator and denominator. The results of numerical calculations (including those based on the solution of the three-dimensional time-dependent Schrödinger equation) agree well with the analytical results.

  1. Dust cloud evolution in sub-stellar atmospheres via plasma deposition and plasma sputtering

    Science.gov (United States)

    Stark, C. R.; Diver, D. A.

    2018-04-01

    Context. In contemporary sub-stellar model atmospheres, dust growth occurs through neutral gas-phase surface chemistry. Recently, there has been a growing body of theoretical and observational evidence suggesting that ionisation processes can also occur. As a result, atmospheres are populated by regions composed of plasma, gas and dust, and the consequent influence of plasma processes on dust evolution is enhanced. Aim. This paper aims to introduce a new model of dust growth and destruction in sub-stellar atmospheres via plasma deposition and plasma sputtering. Methods: Using example sub-stellar atmospheres from DRIFT-PHOENIX, we have compared plasma deposition and sputtering timescales to those from neutral gas-phase surface chemistry to ascertain their regimes of influence. We calculated the plasma sputtering yield and discuss the circumstances where plasma sputtering dominates over deposition. Results: Within the highest dust density cloud regions, plasma deposition and sputtering dominates over neutral gas-phase surface chemistry if the degree of ionisation is ≳10-4. Loosely bound grains with surface binding energies of the order of 0.1-1 eV are susceptible to destruction through plasma sputtering for feasible degrees of ionisation and electron temperatures; whereas, strong crystalline grains with binding energies of the order 10 eV are resistant to sputtering. Conclusions: The mathematical framework outlined sets the foundation for the inclusion of plasma deposition and plasma sputtering in global dust cloud formation models of sub-stellar atmospheres.

  2. Ionised Jets Associated With Massive Young Stellar Objects

    Science.gov (United States)

    Purser, Simon John Derek

    2017-09-01

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

  3. Is it acceptable to use coagulation plasma samples stored at room temperature and 4°C for 24 hours for additional prothrombin time, activated partial thromboplastin time, fibrinogen, antithrombin, and D-dimer testing?

    Science.gov (United States)

    Rimac, V; Coen Herak, D

    2017-10-01

    Coagulation laboratories are faced on daily basis with requests for additional testing in already analyzed fresh plasma samples. This prompted us to examine whether plasma samples stored at room temperature (RT), and 4°C for 24 hours can be accepted for additional prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen (Fbg), antithrombin (AT), and D-dimer testing. We measured PT, aPTT, Fbg in 50 and AT in 30 plasma samples with normal and pathological values, within 4 hours of blood collection (baseline results) and after 24-hours storage at RT (primary tubes), and 4°C (aliquots). D-dimer stability was investigated in 20 samples stored in primary tubes at 4°C. No statistically significant difference between baseline results and results in samples stored at RT and 4°C was observed for PT (P=.938), aPTT (P=.186), Fbg (P=.962), AT (P=.713), and D-dimers (P=.169). The highest median percentage changes were found for aPTT, being more pronounced for samples stored at 4°C (13.0%) than at RT (8.7%). Plasma samples stored both at RT and 4°C for 24 hours are acceptable for additional PT, Fbg, and AT testing. Plasma samples stored 24 hours in primary tubes at 4°C are suitable for D-dimer testing. © 2017 John Wiley & Sons Ltd.

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

    International Nuclear Information System (INIS)

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

    1976-01-01

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

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

    International Nuclear Information System (INIS)

    1998-01-01

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

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

    International Nuclear Information System (INIS)

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

    1996-01-01

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

  7. Beam Dynamics in a Muon Ionisation Cooling Channel

    International Nuclear Information System (INIS)

    Rogers, Chris

    2008-01-01

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

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

    International Nuclear Information System (INIS)

    Djukanovic, M.

    1995-01-01

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

  9. On analytical fits for electron impact ionisation cross sections

    International Nuclear Information System (INIS)

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

    1999-01-01

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

  10. The Radman Guide to the Ionising Radiations Regulations 1985

    International Nuclear Information System (INIS)

    Hughes, D.

    1986-01-01

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

  11. Injuries to embryo and foetus from ionising radiation

    International Nuclear Information System (INIS)

    Devik, F.

    1980-01-01

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

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

    International Nuclear Information System (INIS)

    Young, T.O.

    1982-01-01

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

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

    International Nuclear Information System (INIS)

    Sato, M.

    1982-01-01

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

  14. Use of ionising radiation for food processing applications

    International Nuclear Information System (INIS)

    Ninjoor, V.

    1989-01-01

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

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

    International Nuclear Information System (INIS)

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

    1978-01-01

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

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

    International Nuclear Information System (INIS)

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

    1979-01-01

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

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

    International Nuclear Information System (INIS)

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

    1990-01-01

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

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

    Science.gov (United States)

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

    2011-02-01

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

  19. Biological monitors for low levels of ionising radiation

    International Nuclear Information System (INIS)

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

    1995-01-01

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

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

    Science.gov (United States)

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

    2005-01-01

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

  1. Electron impact ionisation cross sections of iron oxides

    Science.gov (United States)

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

    2017-12-01

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

  2. Biological monitors for low levels of ionising radiation

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

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

  3. Investigation of damage mechanism by ionising radiation on biomolecules

    International Nuclear Information System (INIS)

    Lau How Mooi

    1996-01-01

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

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

    International Nuclear Information System (INIS)

    Fehringer, F.; Seitz, G.

    2004-01-01

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

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

    NARCIS (Netherlands)

    Baar, B.L.M. van

    2000-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Matej Velicky

    2014-09-01

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

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

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

    International Nuclear Information System (INIS)

    Kimman, J.T.N.

    1984-01-01

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

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

    International Nuclear Information System (INIS)

    Sullivan, A.H.

    1984-01-01

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

  10. The potential of organic (electrospray- and atmospheric pressure chemical ionisation) mass spectrometric techniques coupled to liquid-phase separation for speciation analysis.

    Science.gov (United States)

    Rosenberg, Erwin

    2003-06-06

    The use of mass spectrometry based on atmospheric pressure ionisation techniques (atmospheric pressure chemical ionisation, APCI, and electrospray ionisation, ESI) for speciation analysis is reviewed with emphasis on the literature published in and after 1999. This report accounts for the increasing interest that atmospheric pressure ionisation techniques, and in particular ESI, have found in the past years for qualitative and quantitative speciation analysis. In contrast to element-selective detectors, organic mass spectrometric techniques provide information on the intact metal species which can be used for the identification of unknown species (particularly with MS-MS detection) or the confirmation of the actual presence of species in a given sample. Due to the complexity of real samples, it is inevitable in all but the simplest cases to couple atmospheric pressure MS detection to a separation technique. Separation in the liquid phase (capillary electrophoresis or liquid chromatography in reversed phase, ion chromatographic or size-exclusion mode) is particularly suitable since the available techniques cover a very wide range of analyte polarities and molecular mass. Moreover, derivatisation can normally be avoided in liquid-phase separation. Particularly in complex environmental or biological samples, separation in one dimension is not sufficient for obtaining adequate resolution for all relevant species. In this case, multi-dimensional separation, based on orthogonal separation techniques, has proven successful. ESI-MS is also often used in parallel with inductively coupled plasma MS detection. This review is structured in two parts. In the first, the fundamentals of atmospheric pressure ionisation techniques are briefly reviewed. The second part of the review discusses recent applications including redox species, use of ESI-MS for structural elucidation of metal complexes, characterisation and quantification of small organometallic species with relevance to

  11. Electric field measurements on plasma bullets in N2 using four-wave mixing

    NARCIS (Netherlands)

    van der Schans, M.; Böhm, P.; Nijdam, S.; IJzerman, W.L.; Czarnetzki, U.

    2015-01-01

    Atmospheric pressure plasma jets driven by pulsed DC or kHz AC voltages typically consist of discrete guided ionisation waves called plasma bullets. In this work, the electric field of plasma bullets generated in a pulsed DC jet with N2 as feed gas is investigated. Electric field measurements in N2

  12. The use of caffeine to assess high dose exposures to ionising radiation by dicentric analysis

    International Nuclear Information System (INIS)

    Pujol, M.; Puig, R.; Caballin, M. R.; Barrios, L.; Barquinero, J. F.

    2012-01-01

    Dicentric analysis is considered as a 'gold standard' method for biological dosimetry. However, due to the radiation-induced mitotic delay or inability to reach mitosis of heavily damaged cells, the analysis of dicentrics is restricted to doses up to 4-5 Gy. For higher doses, the analysis by premature chromosome condensation technique has been proposed. Here, it is presented a preliminary study is presented in which an alternative method to analyse dicentrics after high dose exposures to ionising radiation (IR) is evaluated. The method is based on the effect of caffeine in preventing the G2/M checkpoint allowing damaged cells to reach mitosis. The results obtained indicate that the co-treatment with Colcemide and caffeine increases significantly increases the mitotic index, and hence allows a more feasible analysis of dicentrics. Moreover in the dose range analysed, from 0 to 15 Gy, the dicentric cell distribution followed the Poisson distribution, and a simulated partial-body exposure has been clearly detected. Overall, the results presented here suggest that caffeine has a great potential to be used for dose-assessment after high dose exposure to IR. (authors)

  13. Changes in amino transferases and muscle proteins when treating pigmeat with ionising rays

    Energy Technology Data Exchange (ETDEWEB)

    Hamm, R; Hofmann, K; Gruenewald, T; Partmann, W [Bundesanstalt fuer Fleischforschung, Kulmbach (F.R. Germany). Inst. fuer Chemie und Physik; Bundesforschungsanstalt fuer Ernaehrung, Karlsruhe [F.R. Germany

    1975-01-01

    Slices of lean pigmeat were treated with electron beams doses of 0.2, 1.0 and 5.0 Mrad. Low irradiation doses led to an increase in the activity of aspartate amino transferase (GOT) and alanin amino transferase (GPT) in the tissue generally and in the sarcoplasm (juice expressed from the muscle). 5 Mrad caused a great reduction in the activity of GOT and GPT in the tissue and the sarcoplasm. It seems doubtful whether this inactivation is due to a destruction of enzyme sulphhydryl groups. Irradiating with 5 Mrad resulted in partial release of the mitochondrial GOT isozyme (GOTsub(M)) into the sarcoplasm. This indicates damage to the mitochondrial membranes by ionising radiation. Irradiating the pigmeat increased the pH of the tissue and lowered its water binding ability (increase in drip). Up to a dose of 1 Mrad the solubility of the sarcoplasmic proteins was not definitely affected, but 5 Mrad caused a considerable drop in protein solubility. Surprisingly a dose of even 5 Mrad did not change the total number of sulphhydryl groups present in the tissue. Sephadex thin layer electrophoresis showed that at 0.2 Mrad there was a drastic decrease in the myosin band and an increase in peptide fragments of low molecular weight, whilst actin was little changed.

  14. Changes in amino transferases and muscle proteins when treating pigmeat with ionising rays

    International Nuclear Information System (INIS)

    Hamm, R.; Hofmann, K.; Gruenewald, T.; Partmann, W.

    1975-01-01

    Slices of lean pigmeat were treated with electron beams doses of 0.2, 1.0 and 5.0 Mrad. Low irradiation doses led to an increase in the activity of aspartate amino transferase (GOT) and alanin amino transferase (GPT) in the tissue generally and in the sarcoplasm (juice expressed from the muscle). 5 Mrad caused a great reduction in the activity of GOT and GPT in the tissue and the sarcoplasm. It seems doubtful whether this inactivation is due to a destruction of enzyme sulphhydryl groups. Irradiating with 5 Mrad resulted in partial release of the mitochondrial GOT isozyme (GOTsub(M)) into the sarcoplasm. This indicates damage to the mitochondrial membranes by ionising radiation. Irradiating the pigmeat increased the pH of the tissue and lowered its water binding ability (increase in drip). Up to a dose of 1 Mrad the solubility of the sarcoplasmic proteins was not definitely affected, but 5 Mrad caused a considerable drop in protein solubility. Surprisingly a dose of even 5 Mrad did not change the total number of sulphhydryl groups present in the tissue. Sephadex thin layer electrophoresis showed that at 0.2 Mrad there was a drastic decrease in the myosin band and an increase in peptide fragments of low molecular weight, whilst actin was little changed. (orig.) [de

  15. Tumour induction by small doses of ionised radiation

    International Nuclear Information System (INIS)

    Putten, L.M. van

    1980-01-01

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

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

    International Nuclear Information System (INIS)

    Przybytniak, G.

    2004-01-01

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

  17. RF System for the MICE Demonstration of Ionisation Cooling

    Energy Technology Data Exchange (ETDEWEB)

    Ronald, K.; et al.

    2017-04-01

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

  18. Dedicated Trigger for Highly Ionising Particles at ATLAS

    CERN Document Server

    Katre, Akshay; The ATLAS collaboration

    2015-01-01

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

  19. On the derivation of the ionisation threshold law

    International Nuclear Information System (INIS)

    Peterkop, R.

    1983-01-01

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

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

    International Nuclear Information System (INIS)

    Oughton, Deborah

    2003-01-01

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

  1. Controllable isotope fractionation with thermal ionisation mass-spectrometers

    International Nuclear Information System (INIS)

    Hebeda, E.H.

    1980-01-01

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

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

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

    International Nuclear Information System (INIS)

    Oughton, D.

    2002-01-01

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

  4. Studies of Non-Targeted Effects of Ionising Radiation

    International Nuclear Information System (INIS)

    Oleg V Belyakov; Heli Mononen; Marjo Peraelae

    2006-01-01

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

  5. Studies of Non-Targeted Effects of Ionising Radiation

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-07-01

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

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

    Science.gov (United States)

    Oughton, Deborah

    2003-01-01

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

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

    International Nuclear Information System (INIS)

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

    1989-01-01

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

  8. The use of ionising radiation screening devices in airports

    International Nuclear Information System (INIS)

    Lazo, T.

    2010-01-01

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

  9. Nuclear and cytoplasmic signalling in the cellular response to ionising radiation

    International Nuclear Information System (INIS)

    Szumiel, Irena

    2001-01-01

    DNA is the universal primary target for ionising radiation; however, the cellular response is highly diversified not only by differential DNA repair ability. The monitoring system for the ionising radiation-inflicted DNA damage consists of 3 apparently independently acting enzymes which are activated by DNA breaks: two protein kinases, ATM (ataxia telangiectasia mutated) and DNA-PK (DNA-dependent protein kinase) and a poly(ADP-ribose) polymerase, PARP-1. These 3 enzymes are the source of alarm signals, which affect to various extents DNA repair, progression through the cell cycle and eventually the pathway to cell death. Their functions probably are partly overlapping. On the side of DNA repair their role consists in recruiting and/or activating the repair enzymes, as well as preventing illegitimate recombination of the damaged sites. A large part of the nuclear signalling pathway, including the integrating role of TP53 has been revealed. Two main signalling pathways start at the plasma membrane: the MAPK/ERK (mitogen and extracellular signal regulated protein kinase family) 'survival pathway' and the SAPK/JNK (stress-activated protein kinase/c-Jun N-terminal kinase) 'cell death pathway'. The balance between them is likely to determine the cell's fate. An additional important 'survival pathway' starts at the insulin-like growth factor type I receptor (IGF-IR), involves phosphoinositide- 3 kinase and Akt kinase and is targeted at inactivation of the pro-apoptotic BAD protein. Interestingly, over-expression of IGF-IR almost entirely abrogates the extreme radiation sensitivity of ataxia telangiectasia cells. When DNA break rejoining is impaired, the cell is unconditionally radiation sensitive. The fate of a repair-competent cell is determined by the time factor: the cell cycle arrest should be long enough to ensure the completion of repair. Incomplete repair or misrepair may be tolerated, when generation of the death signal is prevented. So, the character and timing

  10. Partial Cancellation

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Partial Cancellation. Full Cancellation is desirable. But complexity requirements are enormous. 4000 tones, 100 Users billions of flops !!! Main Idea: Challenge: To determine which cross-talker to cancel on what “tone” for a given victim. Constraint: Total complexity is ...

  11. Study of plasma detachment in a simplified 2D geometry using UEDGE

    International Nuclear Information System (INIS)

    Groth, M.; Porter, G.D.; Rognlien, T.D.; Mahdavi, A.M.

    2002-01-01

    A generic plasma in a two-dimensional slab geometry has been used to study the location of the ionisation front in dependence of the core plasma density and input heating power. The ratio of the recombination to ionisation current and the volumetric momentum losses in the computational domain have been used to quantify the degree of detachment. Contours of constant ratio of these parameters in the core plasma density - heating power parameter space indicate that high volumetric momentum losses can be achieved at high heating power and even low core plasma density. High fractions of recombination to ionisation, however, at high heating power also require high core densities to sufficiently separate the plasma from the target plate. (orig.)

  12. Excitation of higher radial modes of azimuthal surface waves in the electron cyclotron frequency range by rotating relativistic flow of electrons in cylindrical waveguides partially filled by plasmas

    Science.gov (United States)

    Girka, Igor O.; Pavlenko, Ivan V.; Thumm, Manfred

    2018-05-01

    Azimuthal surface waves are electromagnetic eigenwaves of cylindrical plasma-dielectric waveguides which propagate azimuthally nearby the plasma-dielectric interface across an axial external stationary magnetic field. Their eigenfrequency in particular can belong to the electron cyclotron frequency range. Excitation of azimuthal surface waves by rotating relativistic electron flows was studied in detail recently in the case of the zeroth radial mode for which the waves' radial phase change within the layer where the electrons gyrate is small. In this case, just the plasma parameters cause the main influence on the waves' dispersion properties. In the case of the first and higher radial modes, the wave eigenfrequency is higher and the wavelength is shorter than in the case of the zeroth radial mode. This gain being of interest for practical applications can be achieved without any change in the device design. The possibility of effective excitation of the higher order radial modes of azimuthal surface waves is demonstrated here. Getting shorter wavelengths of the excited waves in the case of higher radial modes is shown to be accompanied by decreasing growth rates of the waves. The results obtained here are of interest for developing new sources of electromagnetic radiation, in nano-physics and in medical physics.

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  14. Partial processing

    International Nuclear Information System (INIS)

    1978-11-01

    This discussion paper considers the possibility of applying to the recycle of plutonium in thermal reactors a particular method of partial processing based on the PUREX process but named CIVEX to emphasise the differences. The CIVEX process is based primarily on the retention of short-lived fission products. The paper suggests: (1) the recycle of fission products with uranium and plutonium in thermal reactor fuel would be technically feasible; (2) it would, however, take ten years or more to develop the CIVEX process to the point where it could be launched on a commercial scale; (3) since the majority of spent fuel to be reprocessed this century will have been in storage for ten years or more, the recycling of short-lived fission products with the U-Pu would not provide an effective means of making refabrication fuel ''inaccessible'' because the radioactivity associated with the fission products would have decayed. There would therefore be no advantage in partial processing

  15. Partial gigantism

    Directory of Open Access Journals (Sweden)

    М.М. Karimova

    2017-05-01

    Full Text Available A girl with partial gigantism (the increased I and II fingers of the left foot is being examined. This condition is a rare and unresolved problem, as the definite reason of its development is not determined. Wait-and-see strategy is recommended, as well as correcting operations after closing of growth zones, and forming of data pool for generalization and development of schemes of drug and radial therapeutic methods.

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

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

    DEFF Research Database (Denmark)

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

    2007-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, D C; Pindzola, M S

    1988-10-14

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

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

    Science.gov (United States)

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

    2017-05-04

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

  20. Dusty plasmas

    International Nuclear Information System (INIS)

    Jones, M.E.; Winske, D.; Keinigs, R.; Lemons, D.

    1996-01-01

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The objective of this project has been to develop a fundamental understanding of dusty plasmas at the Laboratory. While dusty plasmas are found in space in galactic clouds, planetary rings, and cometary tails, and as contaminants in plasma enhanced fabrication of microelectronics, many of their properties are only partially understood. Our work has involved both theoretical analysis and self-consistent plasma simulations to understand basic properties of dusty plasmas related to equilibrium, stability, and transport. Such an understanding can improve the control and elimination of plasma dust in industrial applications and may be important in the study of planetary rings and comet dust tails. We have applied our techniques to the study of charging, dynamics, and coagulation of contaminants in plasma processing reactors for industrial etching and deposition processes and to instabilities in planetary rings and other space plasma environments. The work performed in this project has application to plasma kinetics, transport, and other classical elementary processes in plasmas as well as to plasma waves, oscillations, and instabilities

  1. Impact ionisation rate calculations in wide band gap semiconductors

    International Nuclear Information System (INIS)

    Harrison, D.

    1998-09-01

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

  2. RX emission of thin astrophysical plasma: interstellar medium and intra-cluster medium

    International Nuclear Information System (INIS)

    Arnaud, Monique

    1984-01-01

    As previous publications presented an important discrepancy of ionisation rates in astrophysical plasmas, this research thesis first reports a systematic study (by isoelectric sequence) of ionisation cross sections, based on measurements performed by mono-energetic beams, and on quantum assessments. The author proposes simple analytic fits for ionisation rates, for direct ionisation and for excitation-self-ionisation of ions of interest in astrophysics. He reports a critical review of recombination rates published in the literature, and the calculation of radiative recombination rates for different ions (hydrogen-like, helium-like, and lithium-like). Software have then been developed to determine the ionisation rate at the equilibrium and out of it for thin plasma, and to obtain ion fraction tables for different ions (H, He, C, N, O, Ne, Na, Mg, Al, Si, S, Ar, Ca, Fe, Ni). Then, a software integrating recent data on collisional excitation rates has been used to calculate the emission spectrum of a thin plasma with respect to temperature. These results are then used for the study of the interstellar medium and of supernovae remnants, and finally for the study of the intra-cluster medium [fr

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

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

    International Nuclear Information System (INIS)

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

    1985-01-01

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

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

    International Nuclear Information System (INIS)

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

    1996-01-01

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

  6. Trojan horse underdense plasma photocathode acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Karger, Oliver [Hamburg Univ. (Germany). Inst. fuer Experimentalphysik; DESY, FLA Arbeitsbereich Beschleunigerphysik, Hamburg (Germany); Koenigstein, Thomas; Pretzler, Georg [Duesseldorf Univ. (Germany). Inst. fuer Laser- und Plasmaphysik; Rosenzweig, James B. [California Univ., Los Angeles, CA (United States). Dept. of Physics and Astronomy; Hidding, Bernhard [Hamburg Univ. (Germany). Inst. fuer Experimentalphysik; DESY, FLA Arbeitsbereich Beschleunigerphysik, Hamburg (Germany); California Univ., Los Angeles, CA (United States). Dept. of Physics and Astronomy

    2013-07-01

    Relativistic electron beams with small emittance and size are needed for advanced applications such as free electron lasers (FEL) and other coherent light sources in the X-ray regime. Present laser plasma acceleration schemes are hardly able to provide electron beams of sufficient quality on a stable level. The concept of underdense plasma photocathode acceleration uses a beam-driven plasma wave in a two component gas mixture consisting a low ionisation threshold medium (LIT) and a high ionisation threshold medium (HIT) and a low-energy laser pulse. Shapeable electron bunches with sub-fs-length and unprecedented normalized emittance down to 10{sup -9} m rad can be produced. Based on this method, laboratory-sized-experimental setups may enable performance much better than today's conventional coherent hard X-ray sources. The presentation discusses the basic concept, shows recent numero-analytical results and the R and D towards experimental realization.

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

    International Nuclear Information System (INIS)

    Zoetelief, J.; Broerse, J.J.

    1983-01-01

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

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

    International Nuclear Information System (INIS)

    Dimitriou, P.; Kamenopoulou, V.

    2011-01-01

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

  9. The Laboratory appraisal of ionisation chamber smoke detectors

    International Nuclear Information System (INIS)

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

    1980-01-01

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

  10. Application of ionising radiation to the pharmaceutical industry

    International Nuclear Information System (INIS)

    Dittmar, E.

    1975-01-01

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

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

    International Nuclear Information System (INIS)

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

    2000-01-01

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

  12. International conference on individual monitoring of ionising radiation

    International Nuclear Information System (INIS)

    Vanhavere, Filip

    2016-01-01

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

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

    International Nuclear Information System (INIS)

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

    2001-01-01

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

  14. Medical effects of low doses of ionising radiation

    International Nuclear Information System (INIS)

    Coggle, J.E.

    1990-01-01

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

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

    International Nuclear Information System (INIS)

    Legendre, S.

    2006-02-01

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

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

    International Nuclear Information System (INIS)

    Petitfils, A.

    2007-09-01

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

  17. Medical effects and risks of exposure to ionising radiation

    International Nuclear Information System (INIS)

    Mettler, Fred A

    2012-01-01

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

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

    Directory of Open Access Journals (Sweden)

    J. M. Ward

    2007-07-01

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

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-07-01

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

  20. International Conference on Low Doses of Ionising Radiation

    International Nuclear Information System (INIS)

    McEwan, A.C.

    1998-01-01

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

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  2. Dedicated Trigger for Highly Ionising Particles at ATLAS

    CERN Document Server

    Katre, Akshay; The ATLAS collaboration

    2015-01-01

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

  3. Physicochemical Characterization and In Vivo Evaluation of Amorphous and Partially Crystalline Calcium Phosphate Coatings Fabricated on Ti-6Al-4V Implants by the Plasma Spray Method

    Directory of Open Access Journals (Sweden)

    Estevam A. Bonfante

    2012-01-01

    Full Text Available Objective. To characterize the topographic and chemical properties of 2 bioceramic coated plateau root form implant surfaces and evaluate their histomorphometric differences at 6 and 12 weeks in vivo. Methods. Plasma sprayed hydroxyapatite (PSHA and amorphous calcium phosphate (ACP surfaces were characterized by scanning electron microscopy (SEM, interferometry (IFM, X-ray diffraction (XRD, and Fourier transform infrared spectroscopy (FT-IR. Implants were placed in the radius epiphysis, and the right limb of dogs provided implants that remained for 6 weeks, and the left limb provided implants that remained 12 weeks in vivo. Thin sections were prepared for bone-to-implant contact (BIC and bone-area-fraction occupancy (BAFO measurements (evaluated by Friedman analysis <0.05. Results. Significantly, higher Sa (<0.03 and Sq (<0.02 were observed for ACP relative to PSHA. Chemical analysis revealed significantly higher HA, calcium phosphate, and calcium pyrophosphate for the PSHA surface. BIC and BAFO measurements showed no differences between surfaces. Lamellar bone formation in close contact with implant surfaces and within the healing chambers was observed for both groups. Conclusion. Given topographical and chemical differences between PSHA and ACP surfaces, bone morphology and histomorphometric evaluated parameters showed that both surfaces were osseoconductive in plateau root form implants.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1967-07-01

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

  5. A new scheme for solving inhomogeneous Boltzmann equation for electrons in weakly ionised gases

    International Nuclear Information System (INIS)

    Mahmoud, M.O.M.; Yousfi, M.

    1995-01-01

    In the case of weakly ionized gases, the numerical treatment of non-hydrodynamic regime involving spatial variation of distribution function due to boundaries (walls, electrodes, electron source, etc hor-ellipsis) by using direct Boltzmann equation always constitute a challenge if the main collisional processes occurring in non thermal plasmas are to be considered (elastic, inelastic and super-elastic collisions, Penning ionisation, Coulomb interactions, etc hor-ellipsis). In the non-thermal discharge modelling, the inhomogeneous electron Boltzmann equation is needed in order to be coupled for example to a fluid model to take into account the electron non-hydrodynamic effects. This is for example the case of filamentary discharge, in which the space charge electric field due to streamer propagation has a very sharp spatial profile thus leading to important space non-hydrodynamic effects. It is also the case of the cathodic zone of glow discharge where electric field has a rapid spatial decrease until the negative glow. In the present work, a new numerical scheme is proposed to solve the inhomogeneous Boltzmann equation for electrons in the framework of two-term approximation (TTA) taking into account elastic and inelastic processes. Such a method has the usual drawbacks associated with the TTA i.e. not an accurate enough at high E/N values or in presence of high inelastic processes. But the accuracy of this method is considered sufficient because in a next step it is destinated to be coupled to fluid model for charged particles and a chemical kinetic model where the accuracy is of the same order of magnitude or worse. However there are numerous advantages of this method concerning time computing, treatment of non-linear collision processes (Coulomb, Penning, etc hor-ellipsis)

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-12-01

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

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

    Science.gov (United States)

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

    2014-07-01

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

  8. The biological effects of exposure to ionising radiation

    International Nuclear Information System (INIS)

    Higson, D.J.

    2016-01-01

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

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

    International Nuclear Information System (INIS)

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

    2004-01-01

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

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

    Science.gov (United States)

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

    2018-04-01

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

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

    International Nuclear Information System (INIS)

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

    1999-01-01

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

  12. Heat deposition on the partial limiter

    International Nuclear Information System (INIS)

    Itoh, Kimitaka; Itoh, Sanae-I; Nagasaki, Kazunobu.

    1990-01-01

    The effect of the partial limiter in the outermost magnetic surface of toroidal plasmas is studied. The power deposition on the partial limiter and its effect on the temperature profile are analysed. Interpretation in terms of the perpendicular heat conductivity is also discussed. (author)

  13. Total and partial sleep deprivation: Effects on plasma TNF-αRI, TNF-αRII, and IL-6, and reversal by caffeine operating through adenosine A2 receptor

    Science.gov (United States)

    Shearer, William T.; Reuben, James M.; Lee, Bang-Ning; Mullington, Janet; Price, Nicholas; Dinges, David F.

    2000-01-01

    Plasma levels of IL-6 and TNF-α are elevated in individuals who are deprived of sleep. TNF-α regulates expression of its soluble receptors, sTNF-αRI and sTNF-αRII. Sleep deprivation (SD) also increases extracellular adenosine that induces sedation and sleep. An antagonist of adenosine, caffeine, raises exogenous adenosine levels, stimulates the expression of IL-6 and inhibits the release of TNF-α. Our objective was to determine the effect of total SD (TSD) or partial SD (PSD) on the levels of these sleep regulatory molecules in volunteers who experienced SD with or without the consumption of caffeine. Plasma levels of IL-6, sTNF-αRI and sTNF-αRII were assayed by ELISA in samples collected at 90-min intervals from each subject over an 88-hour period. The results were analyzed by the repeated measures ANOVA. Whereas only TSD significantly increased sTNF-αRI over time, caffeine suppressed both sTNF-α receptors in TSD and PSD subjects. The selective increase in the expression of sTNF-αRI and not sTNF-αRII in subjects experiencing TSD with caffeine compared with others experiencing PSD with caffeine has not been previously reported. Moreover, caffeine significantly increased IL-6 in TSD subjects compared with those who did not receive caffeine. However, subjects who were permitted intermittent naps (PSD) ablated the effects of caffeine and reduced their level of IL-6 to that of the TSD group. These data further lend support to the hypothesis that the sTNF-αRI and not the sTNF-αRII plays a significant role in sleep regulation by TNF-α. .

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-10-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-01-15

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

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

    International Nuclear Information System (INIS)

    Boreham, B. W.; Hora, H.

    1997-01-01

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

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

    International Nuclear Information System (INIS)

    Gontier, Y.; Trahin, M.

    1967-01-01

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

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

    International Nuclear Information System (INIS)

    Doerschel, B.; Pretzsch, G.

    1985-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-03-31

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

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

    DEFF Research Database (Denmark)

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

    2006-01-01

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

  2. Electro-acoustic coupling in a plasma gas

    OpenAIRE

    Sutton, Yvonne

    2011-01-01

    Sound emission using an ionised medium has been the subject of research since the beginning of the 20th century. The mechanism involves modulation at an audio frequency of an electrically sustained plasma discharge. In a similar effect to lightning, the charged particles in the plasma respond to the varying energy input. With this comes gas heating, molecular excitation, light emission from relaxation of excited molecular states and acoustic emission resulting from thermal expansion within, a...

  3. Dissociative photo-multiple-ionisation of CO and CO2

    International Nuclear Information System (INIS)

    Bapat, B; Sharma, Vandana; Prajapati, I A; Subramanian, K P; Singh, R K; Lodha, G S

    2007-01-01

    In a photoelectron-photoion coincidence experiment on CO and CO 2 , we have observed the formation and fragmentation of singly to triply charged CO 2 and singly to quadruply charged CO at various energies. Doubly charged cations of both molecules are found to have unstable as well as stable states. Cations with higher charge are found to dissociate promptly. The energy dependence of the relative partial cross-sections in the energy range 125-310 eV are presented

  4. Plasma physics and fusion plasma electrodynamics

    CERN Document Server

    Bers, Abraham

    2016-01-01

    Plasma is a ubiquitous state of matter at high temperatures. The electrodynamics of plasmas encompasses a large number of applications, from understanding plasmas in space and the stars, to their use in processing semiconductors, and their role in controlled energy generation by nuclear fusion. This book covers collective and single particle dynamics of plasmas for fully ionized as well as partially ionized plasmas. Many aspects of plasma physics in current fusion energy generation research are addressed both in magnetic and inertial confinement plasmas. Linear and nonlinear dynamics in hydrodynamic and kinetic descriptions are offered, making both simple and complex aspects of the subject available in nearly every chapter. The approach of dividing the basic aspects of plasma physics as "linear, hydrodynamic descriptions" to be covered first because they are "easier", and postponing the "nonlinear and kinetic descriptions" for later because they are "difficult" is abandoned in this book. For teaching purpose...

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

    NARCIS (Netherlands)

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

    2008-01-01

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

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

    NARCIS (Netherlands)

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

    1998-01-01

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

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

    NARCIS (Netherlands)

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

    2000-01-01

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

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

    International Nuclear Information System (INIS)

    Faria, N.M. de.

    1988-01-01

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

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

    International Nuclear Information System (INIS)

    2000-01-01

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

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

    International Nuclear Information System (INIS)

    Censier, B.

    2006-02-01

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

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

    International Nuclear Information System (INIS)

    Toelgyessy, J.; Harangozo, M.

    2000-01-01

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

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

    Science.gov (United States)

    Taber, Keith S.; Tan, Kim Chwee Daniel

    2007-01-01

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

  13. Investigation of metal ions in fusion plasmas using emission spectroscopy

    International Nuclear Information System (INIS)

    Tale, I.

    2005-01-01

    Full text: The Latvian and Portugal Associations are performing development of advanced plasma - facing system using the liquid metal limiter. The objectives of this project require study of the influence of the liquid metal limiter on the main plasma parameters, including concentration of evaporated metal atoms in plasma. The fusion plasmas are related to the dense hot plasmas. The required average ion temperature according to the ITER project (International Thermonuclear Experimental Reactor) is 8,0 keV (9,3 x 10 7 0 K), the average electron temperature - 8,9 keV (1,04 x 10 8 0 K). Plasma temperature operated in the research tokamak ISSTOK, involved in testing of liquid metal limiter concept is considerably less, being of order of 10 50 K. The ionization degree of metal atoms considerably depends on the plasma ion temperature. Density of metal vapours in plasma can be estimated using the following two spectroscopic methods: The fluorescence of the multiple ionised metal ions in steady state concentration; The charge exchange emission during ionisation of evaporated metal ions. In the first step of development of testing system of metal vapours the equipment and instrumentation for charge exchange spectroscopy of Ga and In has been elaborated taking into account the following features of plasma emission. The Ga emission lines occur on the background high temperature plasma black body emission and stray light. Radial distribution of Ga in plasma in the facing plane of Ga flux is desirable

  14. Dureza e resistência ao desgaste da camada de ZrN formada por nitretação a plasma sobre zircônia parcialmente estabilizada com ítria Hardness and wear resistance of the ZrN layer made by plasma nitriding of yttria partially-stabilized zirconia

    Directory of Open Access Journals (Sweden)

    R. Milani

    2010-07-01

    Full Text Available Corpos-de-prova de zircônia parcialmente estabilizada com ítria foram moldados por prensagem uniaxial, sinterizados e nitretados em plasma de micro-ondas à pressão atmosférica. A camada de ZrN sobre zircônia formou-se a uma taxa de 4 µm.min-1, podendo atingir uma espessura de 500 µm. As amostras foram caracterizadas por meio de medidas de dureza e resistência ao desgaste. A superfície nitretada apresentou dureza superior e resistência ao desgaste similar ao substrato de zircônia.Samples of yttria partially-stabilized zirconia were molded by uniaxial pressing, sintered and nitrided in an atmospheric pressure microwave plasma. This procedure leads to the formation of a ZrN layer whose growth rate and thickness reached 4 µm.min-1 and 500 µm, respectively. The samples were characterized by means of hardness and wear resistance tests. The nitrided surface exhibits superior hardness and wear resistance similar to that of the zirconia substrate.

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

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

    Science.gov (United States)

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

    2012-04-01

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

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

    International Nuclear Information System (INIS)

    Fulford, J.

    2000-05-01

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

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

    International Nuclear Information System (INIS)

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

    1978-01-01

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

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

    Science.gov (United States)

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

    2018-05-01

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

  20. Plasma physics: innovation in energy and industrial technology

    International Nuclear Information System (INIS)

    Harris, J.H.

    2000-01-01

    Full text: Plasmas-ionised gases-are truly ubiquitous. More than 99% of the matter in the universe is in the plasma state. All of the matter that comprises the Earth, and all of the energy that powers it, has been processed through plasma fusion reactions in stars. Plasmas also play a crucial role in the Earth's atmosphere, which screens out harmful radiation, and make long distance radio propagation possible. While the study of plasma physics was originally motivated by astrophysics, the discipline has grown to address terrestrial concerns. These include lighting, welding, the switching of large electrical currents, the processing of materials such as semiconductors, and the quest to build fusion power reactors artificial stars for low-emissions generation of electricity from hydrogen isotopes. Plasma physics is fundamentally multi-disciplinary. It requires understanding not only of the complex collective behaviour of ionised gases in unusual conditions, but also knowledge of the atomic and nuclear physics that determines how plasmas are formed and maintained, and the specialised engineering and instrumentation of the mechanical and electromagnetic containers needed to confine plasmas on Earth. These characteristics make plasma physics a fertile breeding ground for imagination and innovation. This paper draws together examples of innovation stimulated by plasma physics research in the areas of energy, materials, communications, and computation

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

    International Nuclear Information System (INIS)

    Junghans, A.

    1996-01-01

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

  2. Correlations in plasma in thermodynamic equilibrium; Les correlations dans un plasma en equilibre

    Energy Technology Data Exchange (ETDEWEB)

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

    1958-07-01

    This paper treats of a fully, ionized plasma in thermodynamic equilibrium. An attempt is made at reviewing the calculation of spatial correlations in such a plasma. The equation of recurrence and the principle of superposition are used. The linear approximation is first treated. The next higher approximation is studied in the case of a neutral homogeneous and isotropic plasma. (author) [French] Un plasma completement ionise est en equilibre thermodynamique. On tente une mise au point du calcul des correlations de position dans ce plasma. On utilise les equations de recurrence et le principe de superposition. On expose d'abord l'approximation lineaire. Dans le cas d'un plasma neutre homogene et isotrope l'etude est poursuivie a l'approximation suivante. (auteur)

  3. Characterisation of Plasma Filled Rod Pinch electron beam diode operation

    Science.gov (United States)

    MacDonald, James; Bland, Simon; Chittenden, Jeremy

    2016-10-01

    The plasma filled rod pinch diode (aka PFRP) offers a small radiographic spot size and a high brightness source. It operates in a very similar to plasma opening switches and dense plasma focus devices - with a plasma prefill, supplied via a number of simple coaxial plasma guns, being snowploughed along a thin rod cathode, before detaching at the end. The aim of this study is to model the PFRP and understand the factors that affect its performance, potentially improving future output. Given the dependence on the PFRP on the prefill, we are making detailed measurements of the density (1015-1018 cm-3), velocity, ionisation and temperature of the plasma emitted from a plasma gun/set of plasma guns. This will then be used to provide initial conditions to the Gorgon 3D MHD code, and the dynamics of the entire rod pinch process studied.

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

    International Nuclear Information System (INIS)

    2000-01-01

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

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

    NARCIS (Netherlands)

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

    2011-01-01

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

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

    Directory of Open Access Journals (Sweden)

    X. Chen

    2016-11-01

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

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

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

    Science.gov (United States)

    Pounds, Ken

    2013-10-01

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

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

    International Nuclear Information System (INIS)

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

    1999-01-01

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

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

    DEFF Research Database (Denmark)

    Kadhim, Munira; Salomaa, Sisko; Wright, Eric

    2013-01-01

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

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

    International Nuclear Information System (INIS)

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

    2003-01-01

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

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

    International Nuclear Information System (INIS)

    Iyer, G.K.

    1993-01-01

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

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

    International Nuclear Information System (INIS)

    Guerrero Waryn, M.J.

    2005-09-01

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

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

    International Nuclear Information System (INIS)

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

    1981-01-01

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

  15. Research project AUS-10370/CF: electron impact ionization and surface induced reactions of edge plasma constituents

    International Nuclear Information System (INIS)

    Maerk, T.D.

    1999-01-01

    In order to better understand elementary reactions which are taking place at the plasma edge of thermonuclear fusion devices, three areas of research were persuaded: I) Experimental studies about electron ionization of neutrals and ions and electron attachment to molecules, II) Theoretical studies about electron ionisation of neutrals and ions and III) Reactive interaction of molecular ions with surfaces

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

    International Nuclear Information System (INIS)

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

    1978-01-01

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

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

    International Nuclear Information System (INIS)

    Wills, P.; Toner, B.

    1985-01-01

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

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

    International Nuclear Information System (INIS)

    Icre, P.; Rocquigny, H. de

    1995-01-01

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

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

    CERN Document Server

    Benvenuti, C

    1972-01-01

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

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

    International Nuclear Information System (INIS)

    2000-01-01

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

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

    International Nuclear Information System (INIS)

    1978-01-01

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

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

    International Nuclear Information System (INIS)

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

    1992-01-01

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

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

    International Nuclear Information System (INIS)

    Moccia, R.

    1991-01-01

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

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, Bernd

    2015-07-01

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

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

    International Nuclear Information System (INIS)

    Mohd Taufik Dolah; Supian Samat; Taiman Kadni

    1999-01-01

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

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

    International Nuclear Information System (INIS)

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

    1984-01-01

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

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

    Science.gov (United States)

    Sweatman, W. L.

    2006-08-01

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

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

    International Nuclear Information System (INIS)

    Huntley, R.B.

    1981-05-01

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

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

    DEFF Research Database (Denmark)

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

    2012-01-01

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

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

    DEFF Research Database (Denmark)

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

    2012-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-12-15

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

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

    International Nuclear Information System (INIS)

    Akber, R.

    1996-01-01

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

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

    International Nuclear Information System (INIS)

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

    2005-01-01

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

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

    International Nuclear Information System (INIS)

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

    2005-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-11-24

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

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

    International Nuclear Information System (INIS)

    Anon.

    1996-01-01

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

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

    International Nuclear Information System (INIS)

    Zavalic, M.

    2005-01-01

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

  19. Composition and partition functions of partially ionized hydrogen plasma in Non-Local Thermal Equilibrium (Non-LThE) and Non-Local Chemical Equilibrium (Non-LChE)

    International Nuclear Information System (INIS)

    Chen Kuan; Eddy, T.L.

    1993-01-01

    A GTME (Generalized MultiThermodynamic Equilibrium) plasma model is developed for plasmas in both Non-LThE (Non-Local Thermal Equilibrium) and Non-LChE (Non-Local Chemical Equilibrium). The model uses multitemperatures for thermal nonequilibrium and non-zero chemical affinities as a measure of the deviation from chemical equilibrium. The plasma is treated as an ideal gas with the Debye-Hueckel approximation employed for pressure correction. The proration method is used when the cutoff energy level is between two discrete levels. The composition and internal partition functions of a hydrogen plasma are presented for electron temperatures ranging from 5000 to 35000 K and pressures from 0.1 to 1000 kPa. Number densities of 7 different species of hydrogen plasma and internal partition functions of different energy modes (rotational, vibrational, and electronic excitation) are computed for three affinity values. The results differ from other plasma properties in that they 1) are not based on equilibrium properties; and 2) are expressed as a function of different energy distribution parameters (temperatures) within each energy mode of each species as appropriate. The computed number densities and partition functions are applicable to calculating the thermodynamic, transport, and radiation properties of a hydrogen plasma not in thermal and chemical equilibria. The nonequilibrium plasma model and plasma compositions presented in this paper are very useful to the diagnosis of high-speed and/or low-pressure plasma flows in which the assumptions of local thermal and chemical equilibrium are invalid. (orig.)

  20. Electron cyclotron resonance heating assisted plasma startup in the Tore Supra tokamak

    International Nuclear Information System (INIS)

    Bucalossi, J.; Hertout, P.; Lennholm, M.; Saint-Laurent, F.; Bouquey, F.; Darbos, C.; Traisnel, E.

    2009-04-01

    ECRH assisted plasma startup at fundamental resonance is investigated in Tore Supra in view of ITER operation. ECRH pre-ionisation is found to be very efficient allowing plasma initiation in a wide range of pre-fill pressure compared to ohmic startup. Reliable assisted startup has been achieved at the ITER reference toroidal electric field (0.3 V/m) with 160 kW of ECRH. Resonance location scan indicates that the plasma is initiated at the resonance location and that the plasma current channel position had to be real-time controlled since the very beginning of the discharge to obtain robust plasma startup. (authors)

  1. Partial tooth gear bearings

    Science.gov (United States)

    Vranish, John M. (Inventor)

    2010-01-01

    A partial gear bearing including an upper half, comprising peak partial teeth, and a lower, or bottom, half, comprising valley partial teeth. The upper half also has an integrated roller section between each of the peak partial teeth with a radius equal to the gear pitch radius of the radially outwardly extending peak partial teeth. Conversely, the lower half has an integrated roller section between each of the valley half teeth with a radius also equal to the gear pitch radius of the peak partial teeth. The valley partial teeth extend radially inwardly from its roller section. The peak and valley partial teeth are exactly out of phase with each other, as are the roller sections of the upper and lower halves. Essentially, the end roller bearing of the typical gear bearing has been integrated into the normal gear tooth pattern.

  2. Essays on partial retirement

    NARCIS (Netherlands)

    Kantarci, T.

    2012-01-01

    The five essays in this dissertation address a range of topics in the micro-economic literature on partial retirement. The focus is on the labor market behavior of older age groups. The essays examine the economic and non-economic determinants of partial retirement behavior, the effect of partial

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1958-07-01

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

  4. Recurrent Partial Words

    Directory of Open Access Journals (Sweden)

    Francine Blanchet-Sadri

    2011-08-01

    Full Text Available Partial words are sequences over a finite alphabet that may contain wildcard symbols, called holes, which match or are compatible with all letters; partial words without holes are said to be full words (or simply words. Given an infinite partial word w, the number of distinct full words over the alphabet that are compatible with factors of w of length n, called subwords of w, refers to a measure of complexity of infinite partial words so-called subword complexity. This measure is of particular interest because we can construct partial words with subword complexities not achievable by full words. In this paper, we consider the notion of recurrence over infinite partial words, that is, we study whether all of the finite subwords of a given infinite partial word appear infinitely often, and we establish connections between subword complexity and recurrence in this more general framework.

  5. Introduction to Plasma Physics: With Space and Laboratory Applications

    International Nuclear Information System (INIS)

    Browning, P K

    2005-01-01

    whether the rather heavy emphasis on waves is optimal. Newcomers to plasma physics could be left with the impression that plasma physics is mainly a collection of dispersion relations. On the other hand, there is almost no mention of two fluid theory, surely an important subject. Topics relevant to fusion edge plasmas, a subject of growing research interest, are not mentioned at all (for example, sheath theory; also partially ionised plasmas, which are also of course very relevant in space applications). And I am surprised that the discussion of MHD stability does not even mention the kink instability, which is of primary importance both in fusion and solar plasmas. The book is clearly set out and easy to read. Diagrams are clear and helpful. Derivations are properly explained, without leaving too many missing steps. From the point of view of a textbook, it is useful that not too much mathematical knowledge is assumed; for example, when it is needed, the theory of Laplace transforms is explained. A nice feature-very important for a text book-is the presence of end-of-chapter problems. These will be very useful for both students and teachers! It is also good that each chapter has a comprehensive list of references, which might be used to direct more advanced students to the up-to-date scientific literature, as well as suggestions for further reading. Although the primary emphasis is on standard, 'classical' plasma physics, a good attempt is made to present more recent aspects of the subject. For example, after presenting the standard theory of particle orbits-which usefully includes a discussion of Hamiltonian theory as well as guiding centre theory-there is an introduction to the topic of chaotic orbits. Such material is important from an educational point of view, so that from the very beginning students are made aware that plasma physics is a living subject. Overall, this is a very useful addition to the literature. I would recommend it for adoption as a course text for

  6. Radiotherapy and chemotherapy after partial synchronization of cell cycle

    International Nuclear Information System (INIS)

    Hermann, H.J.; Ammon, J.; Nuevemann, M.; Zum Winkel, K.; Technische Hochschule Aachen

    1977-01-01

    Apart from densely ionising radiations, radiotherapy and chemotherapy after partial synchronisation of the cell cycle are, at the moment, the only way to improve the efficiency of a treatment of malignant tumours. The new principle is based on the finding that tumour cells are more sensitive to radiation or chemotherapy in a certain metabolic situation. Partial synchronisation of the cell cycle makes it possible to enrich tumour cells in a certain metabolic state. In order to show the efficiency of such a measure, several methods can be used. Recently, impulse cytophotometry has been replacing these methods, since it permits a quick, simple, and individual control of the synchronisation effect. However, there has not been any clinical experiment yet to prove that tumour cells show a maximum sensitivity to radio- and chemotherapy in the G 2 -M-phase. This is why a number of patients with malignant tumours which could not be operated or treated with the usual radiotherapy or polychemotherapy were treated according to this new therapeutic principle. The results obtained in 233 cases encourage the specialists to continue the experiments. The indication of a treatment after partial synchronisation of the cell cycle should be based on the tumour spread as documented according to the TNM-system. Only when these guidelines are followed will it be possible to explain the problems still unsolved in the principle of radiotherapy and chemotherapy after partial synchronisation of the cell cycle and to carry out radio- and chemotherapy with improved efficiency in the future. (orig./MG) [de

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

    International Nuclear Information System (INIS)

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

    1998-01-01

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

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

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

    International Nuclear Information System (INIS)

    Radford, I.A.

    2003-01-01

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

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

    International Nuclear Information System (INIS)

    Belyakov, O.V.

    2008-12-01

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

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

    International Nuclear Information System (INIS)

    1987-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

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

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

    OpenAIRE

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

    1998-01-01

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

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

    International Nuclear Information System (INIS)

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

    2002-01-01

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

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

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

    International Nuclear Information System (INIS)

    Curtis, L.J.

    1989-01-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

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

    International Nuclear Information System (INIS)

    1983-01-01

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

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

    International Nuclear Information System (INIS)

    Reissland, J.A.

    1982-01-01

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

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

    International Nuclear Information System (INIS)

    Boichenko, Aleksandr M; Yakovlenko, Sergei I

    2000-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-10-15

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

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

    CERN Document Server

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

    2013-01-01

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

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Adams, D.; et al.,

    2013-10-01

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

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

    International Nuclear Information System (INIS)

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

    1987-01-01

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

  8. Annual report on theoretical work of the STGI (section de theorie des gaz ionises)

    International Nuclear Information System (INIS)

    1985-01-01

    This report presents theoretical work on plasma equilibrium, macroscopic plasma evolution and transport codes, waves and RF heating, plasma instabilities magnetic islands and turbulence, transport coefficients and scattering of near-resonance radiation

  9. The 26th IEEE international conference on plasma science

    International Nuclear Information System (INIS)

    1999-01-01

    Some of the sessions covered by this conference are: Basic Processes in Fully and Partially Ionized Plasmas; Slow Wave Devices; Laser-Produced Plasma; Non-Equilibrium Plasma Processing; Space Plasmas and Partially Ionized Gases; Microwave Plasmas; Inertial Confinement Fusion; Plasma Diagnostics; Computational Plasma Physics; Microwave Systems; Laser Produced Plasmas and Dense Plasma Focus; Intense Electron and Ion Beams; Fast Wave Devices; Spherical Configurations and Ball Lightning; Thermal Plasma Chemistry and Processing and Environmental Issues in Plasma Science; Plasma, Ion, and Electron Sources; Fast Wave Devices and Intense Beams; Fast Z-pinches and X-ray Lasers; Plasma Opening Switches; Plasma for Lighting; Intense Beams; Vacuum Microwaves; Magnetic Fusion Energy; and Plasma Thrusters and Arcs. Separate abstracts were prepared for some of the papers in this volume

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

    Energy Technology Data Exchange (ETDEWEB)

    Senftleben, Arne

    2009-10-28

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

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-01-21

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

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

    International Nuclear Information System (INIS)

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

    1999-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-09-15

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

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

    International Nuclear Information System (INIS)

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

    2007-01-01

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

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

    International Nuclear Information System (INIS)

    Zeljezic, D.; Garaj-Vrhovac, V.

    2005-01-01

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

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

    International Nuclear Information System (INIS)

    Palm, Aa.; Mattsson, O.

    2000-01-01

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

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

    International Nuclear Information System (INIS)

    Burkart, W.; Heusser, P.; Vijayalaxmi

    1990-01-01

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

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

    CERN Document Server

    Hansen, O M; Efthymiopoulos, I

    2013-01-01

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

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

    International Nuclear Information System (INIS)

    Weill, J.; Duchene, J.P.

    1958-01-01

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

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

    Science.gov (United States)

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

    2016-06-06

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

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

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

    International Nuclear Information System (INIS)

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

    2003-01-01

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

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

    International Nuclear Information System (INIS)

    Eleveld, H.; Pruppers, M.

    2002-01-01

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

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

    Directory of Open Access Journals (Sweden)

    G. R. Lewis

    2007-11-01

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

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

    International Nuclear Information System (INIS)

    2005-01-01

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

  7. Plasma emission mechanisms

    International Nuclear Information System (INIS)

    Melrose, D.B.

    1985-01-01

    Only three emission processes are thought to play a role in solar radio emission: plasma emission, gyromagnetic emission and bremsstrahlung. In this chapter plasma emission is discussed and the processes involved in its production are treated, namely, the generation of Langmuir turbulence, the partial conversion into fundamental transverse radiation, production of secondary Langmuir waves and the generation of second-harmonic transverse radiation. (U.K.)

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

    Science.gov (United States)

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

    2017-12-01

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

  9. Controlling plasma properties under differing degrees of electronegativity using odd harmonic dual frequency excitation

    Science.gov (United States)

    Gibson, Andrew R.; Gans, Timo

    2017-11-01

    The charged particle dynamics in low-pressure oxygen plasmas excited by odd harmonic dual frequency waveforms (low frequency of 13.56 MHz and high frequency of 40.68 MHz) are investigated using a one-dimensional numerical simulation in regimes of both low and high electronegativity. In the low electronegativity regime, the time and space averaged electron and negative ion densities are approximately equal and plasma sustainment is dominated by ionisation at the sheath expansion for all combinations of low and high frequency and the phase shift between them. In the high electronegativity regime, the negative ion density is a factor of 15-20 greater than the low electronegativity cases. In these cases, plasma sustainment is dominated by ionisation inside the bulk plasma and at the collapsing sheath edge when the contribution of the high frequency to the overall voltage waveform is low. As the high frequency component contribution to the waveform increases, sheath expansion ionisation begins to dominate. It is found that the control of the average voltage drop across the plasma sheath and the average ion flux to the powered electrode are similar in both regimes of electronegativity, despite the differing electron dynamics using the considered dual frequency approach. This offers potential for similar control of ion dynamics under a range of process conditions, independent of the electronegativity. This is in contrast to ion control offered by electrically asymmetric waveforms where the relationship between the ion flux and ion bombardment energy is dependent upon the electronegativity.

  10. Proximal Hamstring Tendinosis and Partial Ruptures.

    Science.gov (United States)

    Startzman, Ashley N; Fowler, Oliver; Carreira, Dominic

    2017-07-01

    Proximal hamstring tendinosis and partial hamstring origin ruptures are painful conditions of the proximal thigh and hip that may occur in the acute, chronic, or acute on chronic setting. Few publications exist related to their diagnosis and management. This systematic review discusses the incidence, treatment, and prognosis of proximal hamstring tendinosis and partial hamstring ruptures. Conservative treatment measures include nonsteroidal anti-inflammatory drugs, physical therapy, rest, and ice. If these measures fail, platelet-rich plasma or shockwave therapy may be considered. When refractory to conservative management, these injuries may be treated with surgical debridement and hamstring reattachment. [Orthopedics. 2017; 40(4):e574-e582.]. Copyright 2017, SLACK Incorporated.

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

    Energy Technology Data Exchange (ETDEWEB)

    Petitfils, A

    2007-09-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Censier, B

    2006-02-15

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

  13. Hyperbolic partial differential equations

    CERN Document Server

    Witten, Matthew

    1986-01-01

    Hyperbolic Partial Differential Equations III is a refereed journal issue that explores the applications, theory, and/or applied methods related to hyperbolic partial differential equations, or problems arising out of hyperbolic partial differential equations, in any area of research. This journal issue is interested in all types of articles in terms of review, mini-monograph, standard study, or short communication. Some studies presented in this journal include discretization of ideal fluid dynamics in the Eulerian representation; a Riemann problem in gas dynamics with bifurcation; periodic M

  14. Successful removable partial dentures.

    Science.gov (United States)

    Lynch, Christopher D

    2012-03-01

    Removable partial dentures (RPDs) remain a mainstay of prosthodontic care for partially dentate patients. Appropriately designed, they can restore masticatory efficiency, improve aesthetics and speech, and help secure overall oral health. However, challenges remain in providing such treatments, including maintaining adequate plaque control, achieving adequate retention, and facilitating patient tolerance. The aim of this paper is to review the successful provision of RPDs. Removable partial dentures are a successful form of treatment for replacing missing teeth, and can be successfully provided with appropriate design and fabrication concepts in mind.

  15. Beginning partial differential equations

    CERN Document Server

    O'Neil, Peter V

    2011-01-01

    A rigorous, yet accessible, introduction to partial differential equations-updated in a valuable new edition Beginning Partial Differential Equations, Second Edition provides a comprehensive introduction to partial differential equations (PDEs) with a special focus on the significance of characteristics, solutions by Fourier series, integrals and transforms, properties and physical interpretations of solutions, and a transition to the modern function space approach to PDEs. With its breadth of coverage, this new edition continues to present a broad introduction to the field, while also addres

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

    International Nuclear Information System (INIS)

    Nodilo, M.; Petkovic, T.

    2011-01-01

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

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

    NARCIS (Netherlands)

    Leenaarts, J.; Wedemeyer-Bohm, S.

    2006-01-01

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

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

    International Nuclear Information System (INIS)

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

    1995-01-01

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

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

    NARCIS (Netherlands)

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

    2009-01-01

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

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

    NARCIS (Netherlands)

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

    2016-01-01

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

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

    International Nuclear Information System (INIS)

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

    1976-01-01

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

  2. Partial knee replacement - slideshow

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/presentations/100225.htm Partial knee replacement - series—Normal anatomy To use the sharing ... A.M. Editorial team. Related MedlinePlus Health Topics Knee Replacement A.D.A.M., Inc. is accredited ...

  3. Beginning partial differential equations

    CERN Document Server

    O'Neil, Peter V

    2014-01-01

    A broad introduction to PDEs with an emphasis on specialized topics and applications occurring in a variety of fields Featuring a thoroughly revised presentation of topics, Beginning Partial Differential Equations, Third Edition provides a challenging, yet accessible,combination of techniques, applications, and introductory theory on the subjectof partial differential equations. The new edition offers nonstandard coverageon material including Burger's equation, the telegraph equation, damped wavemotion, and the use of characteristics to solve nonhomogeneous problems. The Third Edition is or

  4. Computational Methods in Plasma Physics

    CERN Document Server

    Jardin, Stephen

    2010-01-01

    Assuming no prior knowledge of plasma physics or numerical methods, Computational Methods in Plasma Physics covers the computational mathematics and techniques needed to simulate magnetically confined plasmas in modern magnetic fusion experiments and future magnetic fusion reactors. Largely self-contained, the text presents the basic concepts necessary for the numerical solution of partial differential equations. Along with discussing numerical stability and accuracy, the author explores many of the algorithms used today in enough depth so that readers can analyze their stability, efficiency,

  5. Molecular alterations in thyroid tumors induced after exposure to ionising radiation in infancy

    Energy Technology Data Exchange (ETDEWEB)

    Bounacer, A.; Wicker, R.; Sarasin, A.; Suarez, H.G. [Institut Gustave Roussy, 94 - Villejuif (France); Schlumberger, M.; Caillou, B. [Institut de Recherches sur le Cancer, 94 - Villejuif (France)

    1997-03-01

    We investigated the presence of molecular lesions in the ras, gsp and ret genes, in epithelial thyroid tumors developed in patients who had received ionising radiation therapy in infancy for benign or malignant conditions. Our data showed: a similar frequency of ras and gsp activating mutations in radiation-associated and `spontaneous` tumors. However, while the mutations are only transversions in the radiation-associated tumors, they are transversions as well as transitions in the `spontaneous` ones and a mutation in codon 691 giving rise to a polymorphism in the ret gene, and frequently associated to a C-cell hyperplasia in radiation-associated tumors. The frequency of this mutation was significantly higher (60%) in these tumors, than in normal controls (21%) or `spontaneous` epithelial thyroid tumors (23%). (author)

  6. Molecular alterations in thyroid tumors induced after exposure to ionising radiation in infancy

    International Nuclear Information System (INIS)

    Bounacer, A.; Wicker, R.; Sarasin, A.; Suarez, H.G.; Schlumberger, M.; Caillou, B.

    1997-01-01

    We investigated the presence of molecular lesions in the ras, gsp and ret genes, in epithelial thyroid tumors developed in patients who had received ionising radiation therapy in infancy for benign or malignant conditions. Our data showed: a similar frequency of ras and gsp activating mutations in radiation-associated and 'spontaneous' tumors. However, while the mutations are only transversions in the radiation-associated tumors, they are transversions as well as transitions in the 'spontaneous' ones and a mutation in codon 691 giving rise to a polymorphism in the ret gene, and frequently associated to a C-cell hyperplasia in radiation-associated tumors. The frequency of this mutation was significantly higher (60%) in these tumors, than in normal controls (21%) or 'spontaneous' epithelial thyroid tumors (23%). (author)

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

    Science.gov (United States)

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

    1998-07-03

    In view of the biocatalytic production of vanillin, this research focused on the lignin peroxidase (LiP) catalysed oxidation of naturally occurring phenolic derivatives: O-methyl ethers, O-acetyl esters, and O-glucosyl ethers. The ionisation potential (IP) of a series of model compounds was calculated and compared to their experimental conversion by LiP, defining a relative IP threshold of approximately 9.0 eV. Based on this threshold value only the O-acetyl esters and glucosides of isoeugenol and coniferyl alcohol would be potential LiP substrates. Both O-acetyl esters were tested and were shown to be converted to O-acetyl vanillin in molar yields of 51.8 and 2.3%, respectively.

  8. Electrifying atmospheres charging, ionisation and lightning in the solar system and beyond

    CERN Document Server

    Aplin, Karen L

    2013-01-01

    Electrical processes take place in all planetary atmospheres. There is evidence for lightning on Venus, Jupiter, Saturn, Uranus and Neptune, it is possible on Mars and Titan, and cosmic rays ionise every atmosphere, leading to charged droplets and particles. Controversy surrounds the role of atmospheric electricity in physical climate processes on Earth; here, a comparative approach is employed to review the role of electrification in the atmospheres of other planets and their moons. This book reviews the theory, and, where available, measurements, of planetary atmospheric electricity, taken to include ion production and ion-aerosol interactions. The conditions necessary for a global atmospheric electric circuit similar to Earth’s, and the likelihood of meeting these conditions in other planetary atmospheres, are briefly discussed. Atmospheric electrification is more important at planets receiving little solar radiation, increasing the relative significance of electrical forces. Nucleation onto atmospheric ...

  9. Biological effects induced by K photo-ionisation in and near constituent atoms of DNA

    International Nuclear Information System (INIS)

    Touati, A.; Herve du Penhoot, M.A.; Fayard, B.; Champion, C.; Abel, F.; Gobert, F.; Lamoureux, M.; Politis, M.F.; Martins, L.; Ricoul, M.; Sabatier, L.; Sage, E.; Chetioui, A.

    2002-01-01

    In order to assess the lethal efficiency and other biological effects of inner shell ionisations of constituent atoms of DNA ('K' events), experiments were developed at the LURE synchrotron facility using ultrasoft X rays as a probe of K events. The lethal efficiency of ultrasoft X rays above the carbon K threshold was especially investigated using V79 cells and compared with their efficiency to induce double strand breaks in dry plasmid-DNA. A correlation between the K event efficiencies for these processes is shown. Beams of 340 eV were found to be twice as efficient at killing cells than were beams at 250 eV. In addition, a rough two-fold increase of the relative biological effectiveness for dicentric+ring induction has also been observed between 250 and 340 eV radiations. (author)

  10. Burn-up determination of irradiated thoria samples by isotope dilution-thermal ionisation mass spectrometry

    International Nuclear Information System (INIS)

    Aggarwal, S.K.; Jaison, P.G.; Telmore, V.M.; Shah, R.V.; Sant, V.L.; Sasibhushan, K.; Parab, A.R.; Alamelu, D.

    2010-03-01

    Burn-up was determined experimentally using thermal ionization mass spectrometry for two samples from ThO 2 bundles irradiated in KAPS-2. This involved quantitative dissolution of the irradiated fuel samples followed by separation and determination of Th, U and a stable fission product burn-up monitor in the dissolved fuel solution. Stable fission product 148 Nd was used as a burn-up monitor for determining the number of fissions. Isotope Dilution-Thermal Ionisation Mass Spectrometry (ID-TIMS) using natural U, 229 Th and enriched 142 Nd as spikes was employed for the determination of U, Th and Nd, respectively. Atom % fission values of 1.25 ± 0.03 were obtained for both the samples. 232 U content in 233 U determined by alpha spectrometry was about 500 ppm and this was higher by a factor of 5 compared to the theoretically predicted value by ORIGEN-2 code. (author)

  11. Chemical profile of mango (Mangifera indica L.) using electrospray ionisation mass spectrometry (ESI-MS).

    Science.gov (United States)

    Oliveira, Bruno G; Costa, Helber B; Ventura, José A; Kondratyuk, Tamara P; Barroso, Maria E S; Correia, Radigya M; Pimentel, Elisângela F; Pinto, Fernanda E; Endringer, Denise C; Romão, Wanderson

    2016-08-01

    Mangifera indica L., mango fruit, is consumed as a dietary supplement with purported health benefits; it is widely used in the food industry. Herein, the chemical profile of the Ubá mango at four distinct maturation stages was evaluated during the process of growth and maturity using negative-ion mode electrospray ionisation Fourier transform ion cyclotron resonance mass spectrometry (ESI(-)FT-ICR MS) and physicochemical characterisation analysis (total titratable acidity (TA), total soluble solids (TSS), TSS/TA ratio, and total polyphenolic content). Primary (organic acids and sugars) and secondary metabolites (polyphenolic compounds) were mostly identified in the third maturation stage, thus indicating the best stage for harvesting and consuming the fruit. In addition, the potential cancer chemoprevention of the secondary metabolites (phenolic extracts obtained from mango samples) was evaluated using the induction of quinone reductase activity, concluding that fruit polyphenols have the potential for cancer chemoprevention. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Isotope shifts in odd and even energy levels of the neutral and singly ionised gadolinium atom

    International Nuclear Information System (INIS)

    Ahmad, S.A.; Venugopalan, A.; Saksena, G.D.

    1979-01-01

    Isotope shift studies in the gadolinium spectra have been extended in the region 4140 to 4535 A. Isotope shift Δσ(156 to 160) have been measured in 315 lines of the neutral and singly ionised gadolinium atom using a recording Fabry-Perot Spectrometer and gadolinium samples enriched in 156 Gd and 160 Gd isotopes. Some of the Gd I lines studied involve transitions from newly identified high odd levels of 4f 8 6s6p, 4f 7 5d6s7s and 4f 7 5d 3 configurations to low even levels of 4f 8 6s 2 and 4f 7 6s 2 6p configurations. Electronic configurations of the energy levels have been discussed on the basis of observed isotope shifts. In some cases assigned configurations have been revised and probable configurations have been suggested. (author)

  13. Lactobacilli and ionising radiation: an example of the application to meat and meat products

    International Nuclear Information System (INIS)

    Holzapfel, W.H.

    1992-01-01

    Ionising radiation provides a practical pasteurisation method for the terminal treatment of refrigerated vacuum-packaged meat products with the aim of shelf life extension. However, the relatively high radiation resistance (γ-D 10 = 0.70-1.2 kGy) of typical meat Lactobacilli, especially Lb. sake, selectively favours their total domination after treatments with 5 kGy. Typical meat strains show higher resistance (in term of γ-D 10 values the decimal reduction value due to irradiation) in the log (exponential) than in the stationary phase. This phenomenon was observed both in semi-synthetic broth and in meat, and may be explained in terms of a DNA repair mechanism operative during the exponential phase. Packaging under different gas atmospheres resulted in increased resistance to radiation in presence of N 2 , whilst the highest death rate was observed in presence of CO 2 . (orig.) [de

  14. Applying the ionising radiation regulations to radon in the UK workplace

    International Nuclear Information System (INIS)

    Denman, A. R.

    2008-01-01

    As a response to the identification of a health risk from workplace radon in the UK, the Ionising Radiations Regulations include the protection of workers from excessive levels of radon. Employers are required to make risk assessments, and the interpretation of the Health and Safety Executive is that the regulations apply to workplace premises in locations already designated as Radon Affected Areas for domestic purposes, with the difference that in workplaces, it is the maximum winter radon concentration rather than the annual average which is the parameter of interest. This paper discusses the rationale behind the current regulatory environment, outlines the role and duties of Accredited Radiation Protection Advisers and summarises the strategies necessary to conform to the regulations. (authors)

  15. Guidance notes for the protection of persons against ionising radiations arising from medical and dental use

    International Nuclear Information System (INIS)

    1988-01-01

    Guidance notes have been prepared by the NRPB, the Health Departments and the Health and Safety Executive for the protection of all persons against ionising radiations arising from medical and dental use. The guidance notes are a guide to good radiation protection practice consistent with regulatory requirements. The areas covered include medical and dental radiology, diagnostic X-ray equipment for medical and dental radiography, beam therapy and remotely controlled after-loading, brachytherapy, diagnostic and therapeutic uses of unsealed radioactive substances, diagnostic uses of sealed or other solid radioactive sources, patients leaving hospital after administration of radioactive substances, precautions after death of a patient whom radioactive substances have been administered, storage and movement of radioactive substances, disposal of radioactive waste and contingency planning and emergency procedures. (U.K.)

  16. Integrated cross sections for the ionisation of atomic hydrogen by electron impact

    International Nuclear Information System (INIS)

    Konovalov, D.A.; McCarthy, I.E.

    1992-05-01

    Distorted-wave Born approximation (DWBA) calculations are reported for singly-differential and total cross sections for the electron impact ionisation for atomic hydrogen at 25, 40, 60, 100, 150 and 250 eV. The theory is compared with available experiments. At all the energies except 25 eV the theory predicts a lower singly-differential cross section for the low-energy side of the secondary-electron energies (<5 eV), compared to the only available absolute measurements of Shyn (1992). The DWBA calculation is in good agreement with the experiment at 25 eV but only if e-e post-collision interaction is included in the theory in some way. 23 refs., 2 figs

  17. Revisiting Bragg's X-ray microscope: scatter based optical transient grating detection of pulsed ionising radiation.

    Science.gov (United States)

    Fullagar, Wilfred K; Paganin, David M; Hall, Chris J

    2011-06-01

    Transient optical gratings for detecting ultrafast signals are routine for temporally resolved photochemical investigations. Many processes can contribute to the formation of such gratings; we indicate use of optically scattering centres that can be formed with highly variable latencies in different materials and devices using ionising radiation. Coherent light scattered by these centres can form the short-wavelength-to-optical-wavelength, incoherent-to-coherent basis of a Bragg X-ray microscope, with inherent scope for optical phasing. Depending on the dynamics of the medium chosen, the way is open to both ultrafast pulsed and integrating measurements. For experiments employing brief pulses, we discuss high-dynamic-range short-wavelength diffraction measurements with real-time optical reconstructions. Applications to optical real-time X-ray phase-retrieval are considered. Copyright © 2010 Elsevier B.V. All rights reserved.

  18. A novel-type phosphatidylinositol phosphate-interactive, Ca-binding protein PCaP1 in Arabidopsis thaliana: stable association with plasma membrane and partial involvement in stomata closure.

    Science.gov (United States)

    Nagata, Chisako; Miwa, Chika; Tanaka, Natsuki; Kato, Mariko; Suito, Momoe; Tsuchihira, Ayako; Sato, Yori; Segami, Shoji; Maeshima, Masayoshi

    2016-05-01

    The Ca(2+)-binding protein-1 (PCaP1) of Arabidopsis thaliana is a new type protein that binds to phosphatidylinositol phosphates and Ca(2+)-calmodulin complex as well as free Ca(2+). Although biochemical properties, such as binding to ligands and N-myristoylation, have been revealed, the intracellular localization, tissue and cell specificity, integrity of membrane association and physiological roles of PCaP1 are unknown. We investigated the tissue and intracellular distribution of PCaP1 by using transgenic lines expressing PCaP1 linked with a green fluorescence protein (GFP) at the carboxyl terminus of PCaP1. GFP fluorescence was obviously detected in most tissues including root, stem, leaf and flower. In these tissues, PCaP1-GFP signal was observed predominantly in the plasma membrane even under physiological stress conditions but not in other organelles. The fluorescence was detected in the cytosol when the 25-residue N-terminal sequence was deleted from PCaP1 indicating essential contribution of N-myristoylation to the plasma membrane anchoring. Fluorescence intensity of PCaP1-GFP in roots was slightly decreased in seedlings grown in medium supplemented with high concentrations of iron for 1 week and increased in those grown with copper. In stomatal guard cells, PCaP1-GFP was strictly, specifically localized to the plasma membrane at the epidermal-cell side but not at the pore side. A T-DNA insertion mutant line of PCaP1 did not show marked phenotype in a life cycle except for well growth under high CO2 conditions. However, stomata of the mutant line did not close entirely even in high osmolarity, which usually induces stomata closure. These results suggest that PCaP1 is involved in the stomatal movement, especially closure process, in leaves and response to excessive copper in root and leaf as a mineral nutrient as a physiological role.

  19. Optical fibres for fusion plasma diagnostics systems

    International Nuclear Information System (INIS)

    Brichard, B.

    2005-01-01

    The condition to achieve and maintain the ignition of a thermonuclear fusion plasma ignition calls for the construction of a large scale fusion reactor, namely ITER. This reactor is designed to deliver an average fusion power of 500 MW. The burning of fusion plasma at such high power level will release a tremendous amount of energy in the form of particle fluxes and ionising radiation. This energy release, primarily absorbed by the plasma facing components, can significantly degrade the performances of the plasma diagnostic equipment surrounding the machine. To ensure a correct operation of the Tokamak we need to develop highly radiation-resistance devices. In plasma diagnostic systems, optical fibre is viewed as a convenient tool to transport light from the plasma edge to the diagnostic area. Radiation affects the optical performances of the fibre mainly by the occurrence of radiation-induced absorption and luminescence. Both effects degrade the light signal used for plasma diagnostic. SCK-CEN is currently assessing radiation-resistant glasses for optical fibres and is developing the associated qualification procedure. The main objectives of this study were to increase the lifetime of optical components in high radiation background and to develop a radiation resistance optical fibre capable to operate in the radiation background of ITER

  20. Collector floating potentials in a discharge plasma

    International Nuclear Information System (INIS)

    Cercek, M.; Gyergyek, T.

    1999-01-01

    We present the results of a study on electrode floating potential formation in a hot-cathode discharge plasma. The electron component of the plasma is composed from two populations. The high temperature component develops from primary electrons and the cool component from secondary electrons born by ionisation of cold neutral gas. A static, kinetic plasma-sheath model is use to calculate the pre-sheath potential and the floating potential of the electrode. For hot primary electrons a truncated Maxwellian distribution is assumed. The plasma system is also modelled numerically with a dynamic, electrostatic particle simulation. The plasma source injects temporally equal fluxes of ions and electrons with half-Maxwellian velocities. Again, the hot electron distribution is truncated in the high velocity tail. The plasma parameters, such as ion temperature and mass, electron temperatures, discharge voltages, etc. correspond to experimental values. The experimental measurements of the electrode floating potential are performed in weakly magnetised plasma produced with hot cathode discharge in argon gas. Theoretical, simulation and experimental results are compared and they agree very well.(author)

  1. On plasma-neutral gas interaction

    International Nuclear Information System (INIS)

    Venkataramani, N.; Mattoo, S.K.

    1980-01-01

    The importance of plasma-neutral gas interaction layer has been emphasized by pointing out its application to a wide variety of physical phenomena. The interaction of a magnetised plasma stream penetrating a neutral gas cloud is discussed in the light of Alfven's critical velocity and Varma's threshold velocity on the ionising interaction. Interaction of a moving magnetised plasma with a stationary neutral gas has been studied and described. The device comprises of a plasma gun and an interaction region where neutral gas cloud is injected. The interaction region is provided with a transverse magnetic field of upto 1000 G. Several diagnostics deployed at the interaction region to make measurements on the macroscopic parameters of plasma and neutral gas are described. The parameters of discharge circuits are measured with high current and voltage probes. An interaction between a magnetised plasma stream and a neutral gas cloud is demonstrated. It is shown that this interaction does not have Varma's threshold on their relative velocity. The Alfven's critical velocity phenomenon is shown to depend on the integrated column neutral gas density that a plasma stream encounters while penetrating through it and not on the neutral gas density in the range of 10 17 -10 21 m -3 . (auth.)

  2. EPR spectroscopy for the detection of foods treated with ionising radiation

    International Nuclear Information System (INIS)

    Stachowicz, W.; Burlinska, G.; Michalik, J.; Dziedzic-Goclawska, A.; Ostrowski, K.

    1996-01-01

    The advantage of electron paramagnetic resonance spectroscopy (EPR or ESR) as a tool for the control of irradiated food lies in its sensitivity and accuracy. Ionising radiation produces, in irradiated materials, paramagnetic species of different kinds, i.e. radicals, radical-ions and paramagnetic centres, which can be measured by EPR but most of them are not stable enough to be used for the detection of irradiation. It is because radiation-induced paramagnetic species are thermodynamically less stable than surrounding molecules and take part in fast radiolytic reactions leading to the formation of final diamagnetic products that they are not detectable by the EPR method. Most of organic radicals produced by radiation in the liquid phase ae unstable but if the unpaired electron is incorporated into the complex polymeric system as in peptides and polysaccharides and is structurally isolated from the water, its stability is markedly increased. Since 1954 it is known that ionising radiation produces paramagnetic entities in biological materials, cells and tissues and some are stable enough to be observed by EPR spectroscopy at room temperature. The present paper describes and discusses that part of results obtained by this group during the period of ADMIT activity (1989-94) which are original and may be useful to those who will be working in the near future on the development of uniform control systems for the detection of irradiated food. The intention was to focus attention on these facts and data which influence the certainty of the detection in both positive and negative manner. (author)

  3. Chemically modified carbon nanotubes as material enhanced laser desorption ionisation (MELDI) material in protein profiling

    International Nuclear Information System (INIS)

    Najam-ul-Haq, M.; Rainer, M.; Schwarzenauer, T.; Huck, C.W.; Bonn, G.K.

    2006-01-01

    Biomarkers play a potential role in the early detection and diagnosis of a disease. Our aim is to derivatize carbon nanotubes for exploration of the differences in human body fluids e.g. serum, through matrix assisted laser desorption ionisation/time of flight mass spectrometry (MALDI/TOF-MS) that can be related to disease and subsequently to be employed in the biomarker discovery process. This application we termed as the material enhanced laser desorption ionisation (MELDI). The versatility of this technology is meant to increase the amount of information from biological samples on the protein level, which will have a major impact to serve the cause of diagnostic markers. Serum peptides and proteins are immobilized on derivatized carbon nanotubes, which function as binding material. Protein-loaded suspension is placed on a stainless steel target or buckypaper on aluminum target for direct analysis with MALDI-MS. The elution method to wash the bound proteins from carbon nanotubes was employed to compare with the direct analysis procedure. Elution is carried out by MALDI matrix solution to get them out of the entangled nanotubes, which are difficult to desorb by laser due to the complex nanotube structures. The advantage of these optimized methods compared to the conventional screening methods is the improved sensitivity, selectivity and the short analysis time without prior albumin and immunoglobulin depletion. The comparison of similarly modified diamond and carbon nanotubes exhibit differences in their nature to bind the proteins out of serum due to the differences in their physical characteristics. Infrared (IR) spectroscopy provided hint for the presence of tertiary amine peak at the crucial chemical step of iminodiacetic acid addition to acid chloride functionality on carbon nanotubes. Atomic absorption spectroscopy (AAS) was utilized to quantitatively measure the copper capacity of these derivatized carbon nanotubes which is a direct measure of capacity of

  4. A search for non-baryonic dark matter using an ionisation bolometer in the edelweiss experiment

    International Nuclear Information System (INIS)

    Di Stefano, Ph.

    1998-01-01

    The EDELWEISS experiment is an underground direct-detection search for hypothetical supersymmetric WIMPs that might solve the problem of dark matter. We have employed a cryogenic 70 g germanium ionisation bolometer, in which a WIMP would scatter elastically off a nucleus, creating both a heat and an ionisation signal. To offset the various electronic noises present in our necessarily small signals, we have s applied an optimal filtering technique in the frequency domain. This allows us to reach resolutions of 1.2 keV FWHM at 122 keV on north channels. It also provides good separation right down to low energies between the expected signal of nuclear recoils, and the photonic background of electron recoils which ionize more for a given energy. Calibration data show that we are able to reject 99.7 % of this background, while keeping 95% of the signal. However, our 1.17 kg.days of data searching for WIMPs show a third population encroaching on the expected signal. This is probably due to low energy photons or electrons interacting in the outer layers of the crystal, where charges are incompletely collected. Nevertheless, by trading off half of the conserved signal, we still manage to reject 98.5 % of the background. Thus the raw rate of 40 evts/d/kg/keV yields a conservative 90 % upper limit on the signal of 0.6 evts/d/kg/keV. This represents nearly a three orders of magnitude improvement for EDELWEISS, and puts the predicted supersymmetric phase space within two orders of magnitude. (author)

  5. The ionising radiations: a daily reality Las radiaciones ionizantes: una realidad cotidiana

    Directory of Open Access Journals (Sweden)

    Eduardo Gallego Díaz

    2010-12-01

    Full Text Available This paper introduce the nature of the radioactive substances and of the ionising radiation, the effects that they cause on the matter and the available media for their detection and measure, as well as the sources of natural radiation, to which the human being are exposed. Next, in the more detailed part of this paper, it is described the wide range of ionising radiations uses in: medicine, agriculture, earth sciences, biology and in some other scientific fields, that allow to pose its impact in the perspective of facing the ones from natural sources. The article concludes that for avoiding damages it is necessary proper protection against the radioactive substances, but avoiding limitation their beneficial uses in the various ranges described. For finishing this paper, the basic principles of radiation protection are described, due to they are the its principal aim.Este trabajo introduce la naturaleza de las sustancias radiactivas y de la radiación ionizante, los efectos que causa sobre la materia y los medios disponibles para su detección y medida, así como las fuentes de radiación naturales a las que los seres humanos estamos expuestos. Seguidamente, en el apartado más amplio del trabajo, se describen las múltiples aplicaciones de las radiaciones ionizantes en la medicina, la agricultura, la industria, las ciencias de la tierra, la biología y otras ramas, lo que permite poder poner su impacto en perspectiva frente al de las fuentes naturales. La tesis final del artículo es que para evitar sufrir daños resulta necesario protegerse adecuadamente de los efectos nocivos de la radiación y las sustancias radiactivas, pero sin limitar innecesariamente su utilización beneficiosa en los numerosos ámbitos descritos. Ese es el objetivo fundamental de la protección radiológica, cuyos principios básicos se presentan para terminar.

  6. Plasmas for medicine

    Science.gov (United States)

    von Woedtke, Th.; Reuter, S.; Masur, K.; Weltmann, K.-D.

    2013-09-01

    Plasma medicine is an innovative and emerging field combining plasma physics, life science and clinical medicine. In a more general perspective, medical application of physical plasma can be subdivided into two principal approaches. (i) “Indirect” use of plasma-based or plasma-supplemented techniques to treat surfaces, materials or devices to realize specific qualities for subsequent special medical applications, and (ii) application of physical plasma on or in the human (or animal) body to realize therapeutic effects based on direct interaction of plasma with living tissue. The field of plasma applications for the treatment of medical materials or devices is intensively researched and partially well established for several years. However, plasma medicine in the sense of its actual definition as a new field of research focuses on the use of plasma technology in the treatment of living cells, tissues, and organs. Therefore, the aim of the new research field of plasma medicine is the exploitation of a much more differentiated interaction of specific plasma components with specific structural as well as functional elements or functionalities of living cells. This interaction can possibly lead either to stimulation or inhibition of cellular function and be finally used for therapeutic purposes. During recent years a broad spectrum of different plasma sources with various names dedicated for biomedical applications has been reported. So far, research activities were mainly focused on barrier discharges and plasma jets working at atmospheric pressure. Most efforts to realize plasma application directly on or in the human (or animal) body for medical purposes is concentrated on the broad field of dermatology including wound healing, but also includes cancer treatment, endoscopy, or dentistry. Despite the fact that the field of plasma medicine is very young and until now mostly in an empirical stage of development yet, there are first indicators of its enormous

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1961-03-15

    With a view to finding some radiochemical reactions applicable on an industrial scale for evaluating the radioactive waste from nuclear reactors, a systematic study was made of the radiochemical synthesis of thiazinic dyes such as methylene blue and Lauths' violet, on which the first tests were carried out in 1954. The first part of the study concerned the identification and the dosage, during radiolysis, of dyes by means of their absorption spectra after separation from the reaction medium by adsorption chromatography or ion-exchange; other radiolysis products such as ammonium chloride and hydrogen peroxide were also identified. During a later stage by systematically varying the physico-chemical parameters it was possible to determine the most favourable conditions for radio-synthesis; the maximum radiochemical yields obtained had the following values: G (Lauths' violet) 1,65; G (Methylene blue) = 1,75. Furthermore, the study of the influence of variously substituted aminated products on the radiochemical yield showed the possibility of synthesising Bindsehedlers green and Wursters blue by radiochemical methods. Finally the discovery of a fundamental intermediate product, Wursters red, together with the kinetic study of the chemical synthesis of methylene blue made it possible to determine the main stages of the reaction mechanism and to decide which of these stages could be attributed to ionising radiations in the case of the radiochemical synthesis. (author) [French] Dans le but de trouver des reactions radiochimiques susceptibles d'une application industrielle pour valoriser les dechets radioactifs provenant des reacteurs nucleaires, il a ete entrepris une etude systematique de la synthese radiochimique des colorants thiazimiques tels que le Bleu de Methylene et le Violet de Lauth dont les premiers essais ont ete effectues par Loiseleur en 1954. La premiere partie de l'etude a porte sur l'identification et le dosage des colorants formes au cours de la radiolyse

  8. Plasma analysis of inductively coupled impulse sputtering of Cu, Ti and Ni

    Science.gov (United States)

    Loch, D. A. L.; Aranda Gonzalvo, Y.; Ehiasarian, A. P.

    2017-06-01

    Inductively coupled impulse sputtering (ICIS) is a new development in the field of highly ionised pulsed PVD processes. For ICIS the plasma is generated by an internal inductive coil, replacing the need for a magnetron. To understand the plasma properties, measurements of the current and voltage waveforms at the cathode were conducted. The ion energy distribution functions (IEDFs) were measured by energy resolved MS and plasma chemistry was analysed by OES and then compared to a model. The target was operated in pulsed DC mode and the coil was energised by pulsed RF power, with a duty cycle of 7.5%. At a constant pressure (14 Pa) the set peak RF power was varied from 1000-4000 W. The DC voltage to the target was kept constant at 1900 V. OES measurements have shown a monotonic increase in intensity with increasing power. Excitation and ionisation processes were single step for ICIS of Ti and Ni and multi-step for Cu. The latter exhibited an unexpectedly steep rise in ionisation efficiency with power. The IEDFs measured by MS show the material- and time-dependant plasma potential in the range of 10-30 eV, ideal for increased surface mobility without inducing lattice defects. A lower intensity peak, of high energetic ions, is visible at 170 eV during the pulse.

  9. Theory on a partially ionized gas centrifuge

    International Nuclear Information System (INIS)

    Berg, M.S. van den.

    1982-01-01

    This thesis contains a study of some flow processes occurring in the Gaswhirl experiments. In this apparatus a partially ionized gas is forced into rotation by an azimuthal electromagnetic force. After a short introduction in which a motivation is given of our research project, a comprehensive treatment is presented of the principle of rotating plasmas. Further, a historical review is given of rotating plasma systems. A derivation of the fundamental equations is given which describe the flow system mathematically and these are applied to rotating plasmas. The occurrence of secondary flows with radial and axial components is considered. This qualitative picture of secondary whirls is confirmed by measurements reported in the next chapter. The last chapter offers a possible explanation of the occurrence of the transition process in the Gaswhirl apparatus. (Auth.)

  10. Combination treatment with ionising radiation and gefitinib ('Iressa', ZD1839), an epidermal growth factor receptor (EGFR) inhibitor, significantly inhibits bladder cancer cell growth in vitro and in vivo

    International Nuclear Information System (INIS)

    Colquhoun, AJ; Mchugh, LA; Tulchinsky, E.; Kriajevska, M.; Mellon, JK

    2007-01-01

    External beam radiotherapy (EBRT) is the principal bladder-preserving monotherapy for muscle-invasive bladder cancer. Seventy percent of muscle-invasive bladder cancers express epidermal growth factor receptor (EGFR), which is associated with poor prognosis. Ionising radiation (IR) stimulates EGFR causing activation of cytoprotective signalling cascades and thus may be an underlying cause of radioresistance in bladder tumours. We assessed the ability of IR to activate EGFR in bladder cancer cells and the effect of the anti-EGFR therapy, gefitinib on potential radiation-induced activation. Subsequently we assessed the effect of IR on signalling pathways downstream of EGFR. Finally we assessed the activity of gefitinib as a monotherapy, and in combination with IR, using clonogenic assay in vitro, and a murine model in vivo. IR activated EGFR and gefitinib partially inhibited this activation. Radiation-induced activation of EGFR activated the MAPK and Akt pathways. Gefitinib partially inhibited activation of the MAPK pathway but not the Akt pathway. Treatment with combined gefitinib and IR significantly inhibited bladder cancer cell colony formation more than treatment with gefitinib alone (p=0.001-0.03). J82 xenograft tumours treated with combined gefitinib and IR showed significantly greater growth inhibition than tumours treated with IR alone (p=0.04). Combining gefitinib and IR results in significantly greater inhibition of invasive bladder cancer cell colony formation in vitro and significantly greater tumour growth inhibition in vivo. Given the high frequency of EGFR expression by bladder tumours and the low toxicity of gefitinib there is justification to translate this work into a clinical trial. (author)

  11. Partial differential equations

    CERN Document Server

    Evans, Lawrence C

    2010-01-01

    This text gives a comprehensive survey of modern techniques in the theoretical study of partial differential equations (PDEs) with particular emphasis on nonlinear equations. The exposition is divided into three parts: representation formulas for solutions; theory for linear partial differential equations; and theory for nonlinear partial differential equations. Included are complete treatments of the method of characteristics; energy methods within Sobolev spaces; regularity for second-order elliptic, parabolic, and hyperbolic equations; maximum principles; the multidimensional calculus of variations; viscosity solutions of Hamilton-Jacobi equations; shock waves and entropy criteria for conservation laws; and, much more.The author summarizes the relevant mathematics required to understand current research in PDEs, especially nonlinear PDEs. While he has reworked and simplified much of the classical theory (particularly the method of characteristics), he primarily emphasizes the modern interplay between funct...

  12. Plasma heating: NBI ampersand RF, an introduction

    International Nuclear Information System (INIS)

    Koch, R.

    1996-01-01

    The additional heating and non-inductive current-drive methods are reviewed. First, the limitations of ohmic heating in tokamaks are examined and the motivations for using additional heating in tokamaks or other machines are discussed. Next we sketch the principles of heating by injection of fast neutrals - or Neutral Beam Injection (NBI). The principle of the injector is briefly outlined. Positive and negative ion based concepts are discussed. The remainder of the lecture focuses on the processes by which the beam transfers energy to the plasma: the ionisation and slowing-down processes. Next, I make a review of the different heating schemes based on the transfer of electromagnetic energy to the plasma. The different wave heating frequency ranges are listed and the propagation and damping peculiarities are sketched in each domain. Heating in the Alfven and lower hybrid wave domains are described in some more details. 21 refs., 9 figs., 1 tab

  13. Optimization of partial search

    International Nuclear Information System (INIS)

    Korepin, Vladimir E

    2005-01-01

    A quantum Grover search algorithm can find a target item in a database faster than any classical algorithm. One can trade accuracy for speed and find a part of the database (a block) containing the target item even faster; this is partial search. A partial search algorithm was recently suggested by Grover and Radhakrishnan. Here we optimize it. Efficiency of the search algorithm is measured by the number of queries to the oracle. The author suggests a new version of the Grover-Radhakrishnan algorithm which uses a minimal number of such queries. The algorithm can run on the same hardware that is used for the usual Grover algorithm. (letter to the editor)

  14. Plasma antennas: dynamically configurable antennas for communications

    International Nuclear Information System (INIS)

    Borg, G.; Harris, J.

    1999-01-01

    In recent years, the rapid growth in both communications and radar systems has led to a concomitant growth in the possible applications and requirements of antennas. These new requirements include compactness and conformality, rapid reconfigurability for directionality and frequency agility. For military applications, antennas should also allow low absolute or out-of-band radar cross-section and facilitate low probability of intercept communications. Investigations have recently begun worldwide on the use of ionised gases or plasmas as the conducting medium in antennas that could satisfy these requirements. Such plasma antennas may even offer a viable alternative to metal in existing applications when overall technical requirements are considered. A recent patent for ground penetrating radar claims the invention of a plasma antenna for the transmission of pulses shorter than 100 ns in which it is claimed that current ringing is avoided and signal processing simplified compared with a metal antenna. A recent US ONR tender has been issued for the design and construction of a compact and rapidly reconfigurable antenna for dynamic signal reception over the frequency range 1 - 45 GHz based on plasma antennas. Recent basic physics experiments at ANU have demonstrated that plasma antennas can attain adequate efficiency, predictable radiation patterns and low base-band noise for HF and VHF communications. In this paper we describe the theory of the low frequency plasma antenna and present a few experimental results

  15. Auxiliary partial liver transplantation

    NARCIS (Netherlands)

    C.B. Reuvers (Cornelis Bastiaan)

    1986-01-01

    textabstractIn this thesis studies on auxiliary partial liver transplantation in the dog and the pig are reported. The motive to perform this study was the fact that patients with acute hepatic failure or end-stage chronic liver disease are often considered to form too great a risk for successful

  16. Partial Remission Definition

    DEFF Research Database (Denmark)

    Andersen, Marie Louise Max; Hougaard, Philip; Pörksen, Sven

    2014-01-01

    OBJECTIVE: To validate the partial remission (PR) definition based on insulin dose-adjusted HbA1c (IDAA1c). SUBJECTS AND METHODS: The IDAA1c was developed using data in 251 children from the European Hvidoere cohort. For validation, 129 children from a Danish cohort were followed from the onset...

  17. Fundamental partial compositeness

    DEFF Research Database (Denmark)

    Sannino, Francesco; Strumia, Alessandro; Tesi, Andrea

    2016-01-01

    We construct renormalizable Standard Model extensions, valid up to the Planck scale, that give a composite Higgs from a new fundamental strong force acting on fermions and scalars. Yukawa interactions of these particles with Standard Model fermions realize the partial compositeness scenario. Unde...

  18. Partially ordered models

    NARCIS (Netherlands)

    Fernandez, R.; Deveaux, V.

    2010-01-01

    We provide a formal definition and study the basic properties of partially ordered chains (POC). These systems were proposed to model textures in image processing and to represent independence relations between random variables in statistics (in the later case they are known as Bayesian networks).

  19. Partially Hidden Markov Models

    DEFF Research Database (Denmark)

    Forchhammer, Søren Otto; Rissanen, Jorma

    1996-01-01

    Partially Hidden Markov Models (PHMM) are introduced. They differ from the ordinary HMM's in that both the transition probabilities of the hidden states and the output probabilities are conditioned on past observations. As an illustration they are applied to black and white image compression where...

  20. Honesty in partial logic

    NARCIS (Netherlands)

    W. van der Hoek (Wiebe); J.O.M. Jaspars; E. Thijsse

    1995-01-01

    textabstractWe propose an epistemic logic in which knowledge is fully introspective and implies truth, although truth need not imply epistemic possibility. The logic is presented in sequential format and is interpreted in a natural class of partial models, called balloon models. We examine the

  1. Algebraic partial Boolean algebras

    International Nuclear Information System (INIS)

    Smith, Derek

    2003-01-01

    Partial Boolean algebras, first studied by Kochen and Specker in the 1960s, provide the structure for Bell-Kochen-Specker theorems which deny the existence of non-contextual hidden variable theories. In this paper, we study partial Boolean algebras which are 'algebraic' in the sense that their elements have coordinates in an algebraic number field. Several of these algebras have been discussed recently in a debate on the validity of Bell-Kochen-Specker theorems in the context of finite precision measurements. The main result of this paper is that every algebraic finitely-generated partial Boolean algebra B(T) is finite when the underlying space H is three-dimensional, answering a question of Kochen and showing that Conway and Kochen's infinite algebraic partial Boolean algebra has minimum dimension. This result contrasts the existence of an infinite (non-algebraic) B(T) generated by eight elements in an abstract orthomodular lattice of height 3. We then initiate a study of higher-dimensional algebraic partial Boolean algebras. First, we describe a restriction on the determinants of the elements of B(T) that are generated by a given set T. We then show that when the generating set T consists of the rays spanning the minimal vectors in a real irreducible root lattice, B(T) is infinite just if that root lattice has an A 5 sublattice. Finally, we characterize the rays of B(T) when T consists of the rays spanning the minimal vectors of the root lattice E 8

  2. Veterinary applications of ionising radiation HERCA Task Force on Veterinary Applications. Main results of the Questionnaire 'National regulatory requirements with regard to veterinary medical applications of ionising radiation' and conclusions of the TF

    International Nuclear Information System (INIS)

    Van Bladel, Lodewijk; Berlamont, Jolien; Michalczak, Herbert; Balogh, Lajos; Peremans, Kathelijne

    2013-11-01

    In the fall of 2012, the subject of radiation protection in veterinary medicine was raised during the meeting of the HERCA Board. Issues with regard to this subject had been brought to the attention of HERCA by the European College of Veterinary Diagnostic Imaging (ECVDI). In October 2012, the Board decided to charge a small Task Force (TF) to further explore the issues in this field. This TF drew up a questionnaire which looked at the general radiation protection regulatory requirements in veterinary medicine applications of ionizing radiation. The results of this study showed large differences in the requirements applicable in the HERCA member countries. The TF also noticed the increasing use of more complex imaging procedures and of different radio-therapeutic modalities, which may imply greater risks of exposure of humans to ionising radiation. These results were presented during the HERCA Board meeting in Berlin, Germany and on which the Board decided to establish a Working Group on veterinary applications of ionising radiations (WG Vet). The main results of the Questionnaire 'National regulatory requirements with regard to veterinary medicine applications of ionising radiation' is attached in Appendix

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1970-07-01

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

  4. Plasma turbulence

    International Nuclear Information System (INIS)

    Horton, W.

    1998-07-01

    The origin of plasma turbulence from currents and spatial gradients in plasmas is described and shown to lead to the dominant transport mechanism in many plasma regimes. A wide variety of turbulent transport mechanism exists in plasmas. In this survey the authors summarize some of the universally observed plasma transport rates

  5. Eddy covariance flux measurements of ammonia by high temperature chemical ionisation mass spectrometry

    Directory of Open Access Journals (Sweden)

    J. Sintermann

    2011-03-01

    Full Text Available A system for fast ammonia (NH3 measurements with chemical ionisation mass spectrometry (CIMS based on a commercial Proton Transfer Reaction-Mass Spectrometer (PTR-MS is presented. It uses electron transfer reaction as ionisation pathway and features a drift tube of polyetheretherketone (PEEK and silica-coated steel. Heating the instrumental inlet and the drift tube to 180 °C enabled an effective time resolution of ~1 s and made it possible to apply the instrument for eddy covariance (EC measurements. EC fluxes of NH3 were measured over two agricultural fields in Oensingen, Switzerland, following fertilisations with cattle slurry. Air was aspirated close to a sonic anemometer at a flow of 100 STP L min−1 and was directed through a 23 m long 1/2" PFA tube heated to 150 °C to an air-conditioned trailer where the gas was sub-sampled from the large bypass stream. This setup minimised damping of fast NH3 concentration changes between the sampling point and the actual measurement. High-frequency attenuation loss of the NH3 fluxes of 20 to 40% was quantified and corrected for using an empirical ogive method. The instrumental NH3 background signal showed a minor interference with H2O which was characterised in the laboratory. The resulting correction of the NH3 flux after slurry spreading was less than 1‰. The flux detection limit of the EC system was about 5 ng m−2 s−1 while the accuracy of individual flux measurements was estimated 16% for the high-flux regime during these experiments. The NH3 emissions after broad spreading of the slurry showed an initial maximum of 150 μg m−2 s−1 with a fast decline in the following hours.

  6. Non-targeted effects of ionising radiation (note). A new European integrated project, 2006-2010

    International Nuclear Information System (INIS)

    Salomaa, S.; Wright, E.G.; Hildebrandt, G.; Kadhim, M.; Little, M.P.; Prise, K.M.; Belyakov, O.V.

    2007-01-01

    Complete text of publication follows. The general objectives of the NOTE project are: (1) to investigate the mechanisms of nontargeted effects, in particular, bystander effects, genomic instability and adaptive response; (2) to investigate if and how non-targeted effects modulate the cancer risk in the low dose region, and whether they relate to protective or harmful functions; (3) to investigate if ionising radiation can cause non-cancer diseases or beneficial effects at low and intermediate doses; (4) to investigate individual susceptibility and other factors modifying non-targeted responses; (5) to assess the relevance of non-targeted effects for radiation protection and to set the scientific basis for a modern, more realistic, radiation safety system; (6) to contribute to the conceptualisation of a new paradigm in radiation biology that would cover both the classical direct (DNA-targeted) and non-targeted (indirect) effects. The NOTE brings together 19 major European and Canadian groups involved in the discovery, characterisation and mechanistic investigation of non-targeted effects of ionising radiation in cellular, tissue and animal models. The NOTE research activities are organised in six work packages. Four work packages (WPs 2-5) are problem-oriented, focussing on major questions relevant for the scientific basis of the system of radiation protection: WP2 Mechanisms of non-targeted effects, WP3 Non-cancer diseases, WP4 Factors modifying non-targeted responses, WP5 Modelling of non-targeted effects. The integration activities provided by WP6 strengthen the collaboration by supporting the access to infrastructures, mobility and training. WP7 provides dissemination and exploitation activities in the form of workshops and a public website. Managerial activities (WP1) ensure the organisation and structures for decision making, monitoring of progress, knowledge management and efficient flow of information and financing. Coordinator of the NOTE project is Prof

  7. A cascade method of training for the revised CEGB Radiological Safety Rules and the Ionising Radiations Regulations 1985

    International Nuclear Information System (INIS)

    Jackson, J.R.; John, P.G.L.

    1986-01-01

    In order to achieve compliance with the Ionising Radiations Regulations 1985 the CEGB has introduced a revised set of Radiological Safety Rule. These Rules are for implementation at all sites under the Board's control where ionising radiations are used. It was a requirement that the new Safety Rules be brought into operation on a common date and to a consistent standard of performance throughout the industry; this necessitated a considerable training programme to familiarise and inform some 8,000 staff working at a large number of locations. The training week of identified groups of staff varied widely, according to their different levels of authority and responsibility. The paper sets out the means by which the chosen cascade method of training was selected and developed, and gives details of the modular package of training material which was produced. It also relates how the management objectives were met within the constraints of an uncompromising time schedule. (author)

  8. Occupational radiation injuries from ionising rays recorded in the Federal Republic of Germany during the period between 1953 and 1979

    International Nuclear Information System (INIS)

    Soffke, R.

    1986-01-01

    An evaluation of 218 occupational diseases, which were reported between 1953 and 1979 and officially recognised as being caused by ionising rays, showed these to be made up chiefly by skin disorders (61%, equally distributed over acute and chronic forms), even though considerable percentage shares were also calculated for haematological ailments (15%) and bronchial carcinomas developed by uranium miners. There was a total of 42 deaths, 32 of which were ascribed to uranium mining and 10 to haematological diseases. In all, the annual rate of occupational diseases attributed to ionising rays shows a tendency to decline, even though the number of individuals exposed to radiation is increasing. The incidence of radiation injuries was calculated to be in the order of 0.01% for persons at risk of occupational radiation exposure. (orig./EDB) [de

  9. Ionisation differential cross section measurements for N2 at low incident energy in coplanar and non-coplanar geometries

    International Nuclear Information System (INIS)

    Sakaamini, Ahmad; Murray, Andrew James; Amami, Sadek; Madison, Don; Ning, Chuangang

    2016-01-01

    Ionisation triple differential cross sections have been determined experimentally and theoretically for the neutral molecule N 2 over a range of geometries from coplanar to the perpendicular plane. Data were obtained at incident electron energies ∼10 and ∼20 eV above the ionisation potential of the 3 σ g , 1 π u and 2 σ g states, using both equal and non-equal outgoing electron energies. The data were taken with the incident electron beam in the scattering plane ( ψ = 0°), at 45° to this plane and orthogonal to the plane ( ψ = 90°). The set of nine measured differential cross sections at a given energy were then inter-normalised to each other. The data are compared to new calculations using various distorted wave methods, and differences between theory and experiment are discussed. (paper)

  10. Characterisation of tryptic peptides of phosphorylated tyrosine hydroxylase by high-pressure liquid chromatography electrospray ionisation mass spectrometry

    International Nuclear Information System (INIS)

    Graham, Mark E.; Dickson, Phillip W.; Dunkley, Peter R.; Nagy-Felsobuki, Ellak I. von

    2005-01-01

    Tyrosine hydroxylase (TH) is involved in the biosynthesis of catecholamines and is activated by phosphorylation. Phosphorylated TH was analysed using high-pressure liquid chromatography combined with electrospray mass spectrometry (HPLC ESI-MS). Two mass scanning methods were used to detect tryptic cleavage products of TH. In the positive electrospray ionisation mode (ESI+), the peptides that contain the phosphorylation sites of TH were identified. In the alternative method, a phosphopeptide was detected in the negative electrospray ionisation mode (ESI-) using single ion monitoring in combination with a sequential ESI+ switching experiment. A raised baseline interfered with detection of hydrophilic peptides in ESI-, with the signal-to-noise ratio indicating that the method was operating near the limit of detection for a conventional electrospray source. The switching method improved the certainty of identification of phosphopeptides

  11. Preservation of refrigerated calf meat pieces by ionization; Conservation par ionisation de morceaux de viande de veau refrigeres

    Energy Technology Data Exchange (ETDEWEB)

    Hassouna, M. [Ecole Superieure des Industries Alimentaires, El Khadra Tunis (Tunisia); Besbes, M.; Ben Hassen, A.; Mahjoub, A.; Maalej, M.

    1998-07-01

    The influence of five 60Co gamma radiation doses in the range of 1 to 5 kGy on chemical composition and bacteriological counts of pieces of calf meat, partially vacuum - packed before treatment, was studied during storage at + 4 degree C up to 28 days. In vivo thermoluminescence dosimetry (TLD) using dosimeters such as lithium fluoride (LiF) was used as a very sensitive procedure to control both dose delivered to the red meat and its degree of uniformity. These two parameters are generally recommended for the quality control of food irradiation process. While ionizing radiation doses of 1 or 2 kGy were unable to increase the shelf life of treated meat, doses of 3, 4 or 5 kGy were very efficient, and adequate to prevent completely the growth of microorganisms indicating faecal contamination such as total coliforms, faecal coliforms and Enterobacteriaceae; they also kept constant the contents of total mesophilic flora and maintained radioresistant psychrotrophic microflora below the value inducing superficial putrefaction of meat (10{sup 7} CFU cntdot g{sup -1}) at all storage times. Pathogenic germs producing contaminating toxins in foodstuffs such as Salmonella, Staphylococcus aureus and anaerobic sulfite reducing bacteria were totally absent in both control and treated meat. When pieces of meat were irradiated with doses of 3, 4 or 5 kGy, microbial alcalinization and proteolysis revealed by total volatile basic nitrogen were very low during the whole storage period. In addition, total protein did not change as a result of treatment during that period. However, superficial browning and significant variations were observed in water - holding capacity and saturated and unsaturated fatty acids contents in the free fat of treated meat. Ionizing radiation doses had no effect on weight losses and even on the variations of pH after heating of ground calf meat in double boiler at 50, 70 or 90 degree C up to 1 h. However, these modifications very sensitive to cooking

  12. A value-critical assessment of the policy construction of hazard and risk for the safe use of ionising radiation

    International Nuclear Information System (INIS)

    Wallace, A.B.

    1993-01-01

    This paper presents a critique of the concept of ionising radiation safety policy from value perspectives that differ from those of the rationalist scientific. It attempts to present a social interpretation of the constitution of the present methods of policy composition that are primarily based on a conservative, orthodox, scientific paradigm. A modification of this process is then offered to integrate social discourse into the policy construction without compromising the value of the scientific input. 6 refs

  13. Ionising energy treatment for fresh horticultural produce -mandarins and other produce, Trials 1 and 2, May-July 1987

    International Nuclear Information System (INIS)

    McLauchlan, R.L.; Brown, B.I.; Mitchell, G.E.; Aston, J.W.; Wood, A.F.; Isaacs, A.R.; Williams, S.M.; Nottingham, S.M.; Wilson, P.R.; Juffs, H.S.; Johnson, G.I.; Heather, N.W.; Giles, J.E.; Wills, P.A.

    1988-01-01

    Two trials are described on the effect of ionising energy treatment, or irradiation, on the quality, shelf-life and composition of fresh produce, mainly at doses consistent with disinfestation treatment for quarantine purposes. Trial 1, carried out in May 1987, deals with replicated treatments of Imperial mandarins and preliminary observation treatments on a range of other produce. Trial 2 deals with replicated treatments of Ellendale mandarins and preliminary observation treatments on other produce

  14. Statutory Instruments No 144 of 1994. European Communities (Protection of outside workers from ionising radiation) Regulations, 1994

    International Nuclear Information System (INIS)

    1994-04-01

    These Regulations implement Council Directive 90/641 EURATOM of 4 December, 1990 on the operational protection of outside workers exposed to the risk of ionising radiation during their activities in controlled areas. The Regulations provide for the radiation protection of workers liable to receive an exposure of high radiation levels while working away from their employers' premises. The Regulations also apply to workers who come from, or who go to work in, another Member State of the European Community

  15. Beta-decay measurements of neutron-rich thallium, lead, and bismuth by means of resonant laser ionisation

    Science.gov (United States)

    Franchoo, S.; de Witte, H.; Andreyev, A. N.; Cederka¨Ll, J.; Dean, S.; de Smet, A.; Eeckhaudt, S.; Fedorov, D. V.; Fedosseev, V. N.; G´Rska, M.; Huber, G.; Huyse, M.; Janas, Z.; Ko¨Ster, U.; Kurcewicz, W.; Kurpeta, J.; Mayer, P.; Płchocki, A.; van de Vel, K.; van Duppen, P.; Weissman, L.; Isolde Collaboration

    2004-04-01

    Neutron-rich thallium, lead, and bismuth isotopes were investigated at the ISOLDE facility. After mass separation and resonant laser ionisation of the produced activity, new spectroscopic data were obtained for 215,218Bi and 215Pb. An attempt to reach heavy thallium had to be abandoned because of a strong francium component in the beam that gave rise to a neutron background through (α,n) reactions on the aluminium walls of the experimental chamber.

  16. Rapid and simultaneous determination of polychlorinated biphenyls and their main metabolites (hydroxylated and methyl sulfonyl) by gas chromatography coupled to mass spectrometry: Comparison of different ionisation modes

    International Nuclear Information System (INIS)

    Castro-Puyana, M.; Herrero, L.; González, M.J.; Gómara, B.

    2013-01-01

    Graphical abstract: -- Highlights: •Simultaneous determination of PCB, OH-PCBs and MeSO 2 -PCBs in a single GC–MS run. •Two different ionisation modes (EI and ECNI) are studied and compared. •The analytical characterisation of both methods is satisfactory. •Better LODs are achieved using ECNI-MS as ionisation mode. •The developed methodology is successfully applied to fish liver oil. -- Abstract: Instrumental methods based on gas chromatography coupled to mass spectrometry (GC–MS) have been developed and compared using two different MS ionisation modes, electron impact (EI) and electron capture negative ionisation (ECNI), for the fast, quantitative and simultaneous determination of polychlorinated biphenyls (PCBs) and their main metabolites (hydroxylated PCBs, OH-PCBs, and methyl sulfone PCBs, MeSO 2 -PCBs). Parameters affecting chromatographic separation and MS detection were evaluated in order to achieve the highest selectivity and sensitivity for both operation modes. The analytical characteristics of the developed methods were studied and compared in terms of linear range, limits of detection (LODs), limits of quantification (LOQs), and instrumental precision (repeatability and intermediate precision). Both ionisation methods showed similar precision, being relative standard deviations (RSD, %) lower than 9% and 14% for repeatability and intermediate precision, respectively. However, better LODs (from 0.01 to 0.14 pg injected for the three families of congeners studied) were achieved using ECNI-MS as ionisation mode. The suitability of the developed method was demonstrated through their application to fish liver oil samples

  17. Simulation and measurements of the response of an air ionisation chamber exposed to a mixed high-energy radiation field

    International Nuclear Information System (INIS)

    Vincke, H.; Forkel-Wirth, D.; Perrin, D.; Theis, C.

    2005-01-01

    CERN's radiation protection group operates a network of simple and robust ionisation chambers that are installed inside CERN's accelerator tunnels. These ionisation chambers are used for the remote reading of ambient dose rate equivalents inside the machines during beam-off periods. This Radiation Protection Monitor for dose rates due to Induced Radioactivity ('PMI', trade name: PTW, Type 34031) is a non-confined air ionisation plastic chamber which is operated under atmospheric pressure. Besides its current field of operation it is planned to extend the use of this detector in the Large Hadron Collider to measure radiation under beam operation conditions to obtain an indication of the machine performance. Until now, studies of the PMI detector have been limited to the response to photons. In order to evaluate its response to other radiation components, this chamber type was tested at CERF, the high-energy reference field facility at CERN. Six PMI detectors were installed around a copper target being irradiated by a mixed hadron beam with a momentum of 120 GeV c -1 . Each of the chosen detector positions was defined by a different radiation field, varying in type and energy of the incident particles. For all positions, detailed measurements and FLUKA simulations of the detector response were performed. This paper presents the promising comparison between the measurements and simulations and analyses the influence of the different particle types on the resulting detector response. (authors)

  18. Control and calculation of the titanium sublimation pumping speed and re-ionisation in the MAST neutral beam injectors

    International Nuclear Information System (INIS)

    McAdams, R.

    2015-01-01

    Highlights: • The titanium sublimation pumps for the MAST neutral beam injectors are described. • Evaporation regimes are established to give constant pumping speed for the titanium sublimation pumps. • The MCNP code is used to calculate the pumping speeds and gas profiles in the neutral beam injectors. • The gas profiles are then used to calculate the level of re-ionisation in the beamline. - Abstract: A high pumping speed is required in neutral beam injectors to minimise re-ionisation of the neutral beams. The neutral beam injectors on MAST use titanium sublimation pumps. These pumps do not have a constant pumping speed; their pumping speed depends on the gettering surface history and on both the integrated and applied gas load. In this paper we describe a method of maintaining a constant pumping speed, through different evaporation schemes, specifically suitable for operations of the MAST neutral beam injector beamlines for both short and relatively long beam pulses by measurement of the pressure in the beamline. In addition the MCNP code is then used to calculate the pumping speed and gas profile in the beamline by adjusting the input pumping speed to match the measured pressure. This allows the resulting gas profile to be used for calculation of the re-ionisation levels and an example is given

  19. Molecular mechanisms of plant response to ionising radiation. Exploration of the glucosinolate role in the anti-oxidative response

    International Nuclear Information System (INIS)

    Gicquel, M.

    2012-01-01

    Terrestrial organisms are exposed to low doses of ionising radiation from natural or anthropogenic sources. The major effects of the radiations are due to DNA deterioration and water radiolysis which generates an oxidative stress by free radical production. Plants constitute good models to study the effects of ionising radiations and the search of antioxidant molecules because of their important secondary metabolism. Thus this thesis, funded by the Brittany region, characterized the physiological and molecular response of the model plant Arabidopsis thaliana to low (10 Gy) and moderate (40 Gy) doses of ionising radiation, and was therefore interested in glucosinolates, characteristic compounds of the Brassicaceae family. The global proteomic and transcriptomic studies carried out on this model revealed (1) a common response for both doses dealing with the activation of DNA repair mechanisms, cell cycle regulation and protection of cellular structures; (2) an adjustment of the energetic metabolism and an activation of secondary compounds biosynthesis (i.e. glucosinolates and flavonoids) after the 10 Gy dose; (3) an induction of enzymatic control of ROS, the regulation of cellular components recycling and of programmed cell death after the 40 Gy dose. The potential anti-oxidative role of glucosinolates was then explored. The in vitro anti-oxidative power of some glucosinolates and their derivative products were demonstrated. Their modulating effects against irradiation-induced damages were then tested in vivo by simple experimental approaches. The importance of the glucosinolate level to give a positive or negative effect was demonstrated. (author)

  20. FREQUENCY OF CHROMOSOMAL ABERRATIONS AND MICRONUCLEI IN HORSE LYMPHOCYTES FOLLOWING IN VITRO EXPOSURE TO LOW DOSE IONISING RADIATION

    Directory of Open Access Journals (Sweden)

    Dunja Rukavina

    2012-07-01

    Full Text Available Ionising radiation is known to cause chromosomal instability, which is observed as increased frequency of chromosomal aberration and micronuclei. These are listed as reliable criteria in biological dosimetry. Numerous experiments conducted on both animal and plant models demonstrated that increase in radiation dosage is followed by increased mutation frequency, and that mutations occur even at the lowest exposure. We used horse blood in vitro irradiated by low doses of ionizing radiation. Cultivation of peripheral blood lymphocytes and micronucleus test were used as biomarkers of genetic damage. The observed aberrations were recorded and classified in accordance with the International System of Cytogenetic Nomenclature. Micronuclei were identified on the basis of criteria proposed by Fenech et al. (8. Analysis of chromosomal aberration showed increased frequency of aberrations in blood cultures exposed to 0,1 Gy and 0,2 Gy compared to the controls. Microscopic analysis of chromosomal damage in in vitro micronucleus test revealed that the applied radiation dose induced micronuclei while no binucleated cells with micronuclei were found in lymphocytes that were not irradiated. In this paper we analysed the influence of low dose ionising radiation on frequency of chromosomal aberration and micronuclei in horse lymphocytes following in vitro exposure to X-rays (0,1 Gy and 0,2 Gy. Key words: chromosomal aberrations, micronuclei, ionising radiation, horse lymphocytes

  1. Partially composite Higgs models

    DEFF Research Database (Denmark)

    Alanne, Tommi; Buarque Franzosi, Diogo; Frandsen, Mads T.

    2018-01-01

    We study the phenomenology of partially composite-Higgs models where electroweak symmetry breaking is dynamically induced, and the Higgs is a mixture of a composite and an elementary state. The models considered have explicit realizations in terms of gauge-Yukawa theories with new strongly...... interacting fermions coupled to elementary scalars and allow for a very SM-like Higgs state. We study constraints on their parameter spaces from vacuum stability and perturbativity as well as from LHC results and find that requiring vacuum stability up to the compositeness scale already imposes relevant...... constraints. A small part of parameter space around the classically conformal limit is stable up to the Planck scale. This is however already strongly disfavored by LHC results. in different limits, the models realize both (partially) composite-Higgs and (bosonic) technicolor models and a dynamical extension...

  2. Erosion of pyrolytic carbon under high surface energy deposition from a pulsed hydrogen plasma

    International Nuclear Information System (INIS)

    Bolt, H.

    1992-01-01

    Carbon materials are widely applied as plasma facing materials in nuclear fusion devices and are also the prime candidate materials for the next generation of experimental fusion reactors. During operation these materials are frequently subjected to high energy deposition from plasma disruptions. The erosion of carbon materials is regarded as the main issue governing the operational lifetime of plasma facing components. Laboratory experiments have been performed to study the thermal erosion behaviour of carbon in a plasma environment. In the experiments the surface of pyrolytic carbon specimens was exposed to pulsed energy deposition of up to 3.8 MJ m -2 from a hydrogen plasma. The behaviour of the eroded carbon species in the plasma was measured by time-resolved and space-resolved spectroscopy. Intense line radiation of ionic carbon has been measured in the plasma in front of the carbon surface. The results show that the eroded carbon is immediately ionised in the vicinity of the material surface, with a fraction of it being ionised to the double-charged state. (Author)

  3. Photogenic partial seizures.

    Science.gov (United States)

    Hennessy, M J; Binnie, C D

    2000-01-01

    To establish the incidence and symptoms of partial seizures in a cohort of patients investigated on account of known sensitivity to intermittent photic stimulation and/or precipitation of seizures by environmental visual stimuli such as television (TV) screens or computer monitors. We report 43 consecutive patients with epilepsy, who had exhibited a significant EEG photoparoxysmal response or who had seizures precipitated by environmental visual stimuli and underwent detailed assessment of their photosensitivity in the EEG laboratory, during which all were questioned concerning their ictal symptoms. All patients were considered on clinical grounds to have an idiopathic epilepsy syndrome. Twenty-eight (65%) patients reported visually precipitated attacks occurring initially with maintained consciousness, in some instances evolving to a period of confusion or to a secondarily generalized seizure. Visual symptoms were most commonly reported and included positive symptoms such as coloured circles or spots, but also blindness and subjective symptoms such as "eyes going funny." Other symptoms described included nonspecific cephalic sensations, deja-vu, auditory hallucinations, nausea, and vomiting. No patient reported any clear spontaneous partial seizures, and there were no grounds for supposing that any had partial epilepsy excepting the ictal phenomenology of some or all of the visually induced attacks. These findings provide clinical support for the physiological studies that indicate that the trigger mechanism for human photosensitivity involves binocularly innervated cells located in the visual cortex. Thus the visual cortex is the seat of the primary epileptogenic process, and the photically triggered discharges and seizures may be regarded as partial with secondary generalization.

  4. Arthroscopic partial medial meniscectomy

    Directory of Open Access Journals (Sweden)

    Dašić Žarko

    2011-01-01

    Full Text Available Background/Aim. Meniscal injuries are common in professional or recreational sports as well as in daily activities. If meniscal lesions lead to physical impairment they usually require surgical treatment. Arthroscopic treatment of meniscal injuries is one of the most often performed orthopedic operative procedures. Methods. The study analyzed the results of arthroscopic partial medial meniscectomy in 213 patients in a 24-month period, from 2006, to 2008. Results. In our series of arthroscopically treated medial meniscus tears we noted 78 (36.62% vertical complete bucket handle lesions, 19 (8.92% vertical incomplete lesions, 18 (8.45% longitudinal tears, 35 (16.43% oblique tears, 18 (8.45% complex degenerative lesions, 17 (7.98% radial lesions and 28 (13.14% horisontal lesions. Mean preoperative International Knee Documentation Committee (IKDC score was 49.81%, 1 month after the arthroscopic partial medial meniscectomy the mean IKDC score was 84.08%, and 6 months after mean IKDC score was 90.36%. Six months after the procedure 197 (92.49% of patients had good or excellent subjective postoperative clinical outcomes, while 14 (6.57% patients subjectively did not notice a significant improvement after the intervention, and 2 (0.93% patients had no subjective improvement after the partial medial meniscectomy at all. Conclusion. Arthroscopic partial medial meniscetomy is minimally invasive diagnostic and therapeutic procedure and in well selected cases is a method of choice for treatment of medial meniscus injuries when repair techniques are not a viable option. It has small rate of complications, low morbidity and fast rehabilitation.

  5. BOOK REVIEW: Introduction to Plasma Physics: With Space and Laboratory Applications

    Science.gov (United States)

    Browning, P. K.

    2005-07-01

    whether the rather heavy emphasis on waves is optimal. Newcomers to plasma physics could be left with the impression that plasma physics is mainly a collection of dispersion relations. On the other hand, there is almost no mention of two fluid theory, surely an important subject. Topics relevant to fusion edge plasmas, a subject of growing research interest, are not mentioned at all (for example, sheath theory; also partially ionised plasmas, which are also of course very relevant in space applications). And I am surprised that the discussion of MHD stability does not even mention the kink instability, which is of primary importance both in fusion and solar plasmas. The book is clearly set out and easy to read. Diagrams are clear and helpful. Derivations are properly explained, without leaving too many missing steps. From the point of view of a textbook, it is useful that not too much mathematical knowledge is assumed; for example, when it is needed, the theory of Laplace transforms is explained. A nice feature—very important for a text book—is the presence of end-of-chapter problems. These will be very useful for both students and teachers! It is also good that each chapter has a comprehensive list of references, which might be used to direct more advanced students to the up-to-date scientific literature, as well as suggestions for further reading. Although the primary emphasis is on standard, `classical' plasma physics, a good attempt is made to present more recent aspects of the subject. For example, after presenting the standard theory of particle orbits—which usefully includes a discussion of Hamiltonian theory as well as guiding centre theory—there is an introduction to the topic of chaotic orbits. Such material is important from an educational point of view, so that from the very beginning students are made aware that plasma physics is a living subject. Overall, this is a very useful addition to the literature. I would recommend it for adoption as a course

  6. Plasma properties

    International Nuclear Information System (INIS)

    Weitzner, H.

    1990-06-01

    This paper discusses the following topics: MHD plasma activity: equilibrium, stability and transport; statistical analysis; transport studies; edge physics studies; wave propagation analysis; basic plasma physics and fluid dynamics; space plasma; and numerical methods

  7. Hierarchical partial order ranking

    International Nuclear Information System (INIS)

    Carlsen, Lars

    2008-01-01

    Assessing the potential impact on environmental and human health from the production and use of chemicals or from polluted sites involves a multi-criteria evaluation scheme. A priori several parameters are to address, e.g., production tonnage, specific release scenarios, geographical and site-specific factors in addition to various substance dependent parameters. Further socio-economic factors may be taken into consideration. The number of parameters to be included may well appear to be prohibitive for developing a sensible model. The study introduces hierarchical partial order ranking (HPOR) that remedies this problem. By HPOR the original parameters are initially grouped based on their mutual connection and a set of meta-descriptors is derived representing the ranking corresponding to the single groups of descriptors, respectively. A second partial order ranking is carried out based on the meta-descriptors, the final ranking being disclosed though average ranks. An illustrative example on the prioritisation of polluted sites is given. - Hierarchical partial order ranking of polluted sites has been developed for prioritization based on a large number of parameters

  8. Plasma accelerators

    International Nuclear Information System (INIS)

    Bingham, R.; Angelis, U. de; Johnston, T.W.

    1991-01-01

    Recently attention has focused on charged particle acceleration in a plasma by a fast, large amplitude, longitudinal electron plasma wave. The plasma beat wave and plasma wakefield accelerators are two efficient ways of producing ultra-high accelerating gradients. Starting with the plasma beat wave accelerator (PBWA) and laser wakefield accelerator (LWFA) schemes and the plasma wakefield accelerator (PWFA) steady progress has been made in theory, simulations and experiments. Computations are presented for the study of LWFA. (author)

  9. Cancer mortality risk of nuclear power workers due to the exposure of ionising radiation in Germany

    International Nuclear Information System (INIS)

    Fehringer, F.; Seitz, G.; Hammer, G.P.; Blettner, M.

    2006-01-01

    A cohort study of German nuclear power workers was set up to investigate overall and cancer mortality risk related to a chronic exposure to ionising radiation of low-level dose. The German study was performed as a part of an international study carried out by the International Agency for Research on Cancer (IARC), Lyon. First results of the international study have been published recently [1]. German data are not yet included in this analysis. The German cohort consists of 4844 employees from 10 nuclear power plants. All persons who worked in these nuclear power plants in 1991 or started employment between 1991 und 1997 are included (except for employees of one plant, whose observation period started in 1992). These persons accumulated about 31,000 person years. Overall, 68 deaths were observed in the observation period between 1.1.1991-31.12.1997. Standardized mortality ratios (SMR) were computed for all causes of death, all cancers, cardiovascular diseases, external causes, and all other causes. Overall, a strong healthy worker effect was observed (SMR=0.52 [95% CI: 0.41;0.67]). No increase in total cancer mortality was seen (SMR=0.85 [95% CI: 0.53;1.30]). However, numbers are too small for stable risk estimates and further effort is under way to complete the cohort in terms of power plants and to extend the follow-up until 2005. (authors)

  10. Nailfold Capillaroscopic Monitoring as Preventive Medicine in Subjects Exposed to Ionising Radiation

    International Nuclear Information System (INIS)

    Pennarola, R.; Perdereau, B.; Trenta, G.; Cosset, J. M.

    2004-01-01

    Capillaroscopy consists of in vivo observation of microvessels using special microscopes with a short focal length. Normally, when looking at the nail fold, where capillaroscopy is commonly used, the capillaries ares arranged like hairpins, lined up in parallel or obliquely to the field of vision in three or four layers above the subpapillary venous network, approximately 20 loops per mm''2. Ionising radiation can badly damage the skin and underlying tissues. The capillary network is among the first structures to show an effect. Moderate doses of radiation cause damage endothelial cells with hypertrophy or hyperplasia of endothelial cells, which can block capillaries while having little effect on larger vessels. Occlusion of capillaries impedes blood flow no only in nearby tissue but also in areas farther away. Capillaroscopic examination of the nail fold is irreplaceable in the field of radioprotection especially in cases of exposure of the hands. Nailfold capillaroscopic monitoring lets us observe the degree to which qualitative and quantitative alterations of the capillaries are a function of the evolution of the lesion. Therefore, for biological monitoring of subjects exposed to radiation the authors propose to use this microvascular quantitative analysis of the nailfold region. Experience, matured over many years by our team, highlights the relation between the sum of repeated exposure and the importance of tissue alterations evidenced by microcirculation. (Author) 9 refs

  11. Framework for the Protection of the Environment from Ionising Radiation (invited paper)

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-07-01

    A framework is proposed for the protection of the environment from ionising radiation. Key components include the assessment of the environmental transfer of radionuclides and uptake of radionuclides by organisms, the adaptation of existing dosimetric models to calculate absorbed doses and studies concerning dose-effects relationships for selected organisms. The proposed framework will also make use of 'reference' organisms, selection of which will be based on a number of criteria, e.g. radiosensitivity, ubiquity, and will involve the development of standardised biota exposure units which might integrate the Relative Biological Effect (RBE) of the radiation under consideration. In the second part of the study, initial efforts have been made to develop a computerised system in order to provide a simple example of how components of this framework may be formulated. An equilibrium absorbed dose constant model has been used for high LET (Linear Energy Transfer) radionuclides combined with the application of an absorbed fraction for {gamma}-emitting radionuclides. Generalised specific activity information for selected radionuclides from Norwegian marine environments have been used as model input data. For the radionuclides considered, total doses for marine organisms (lobster, mussels, seaweed) ranged between 1.35-2.5 mGy.y{sup -1}, mainly attributable to {sup 40}K and {sup 210}Po. Such levels are well below those where observable effects might be expected. (author)

  12. Impact of chronic, low-level ionising radiation exposure on terrestrial invertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Hingston, J.; Wood, M.D.; Copplestone, D.; Zinger, I. [Liverpool Univ., School of Biological Sciences, Merseyside (United Kingdom)

    2004-07-01

    There is a need to confirm that the environment is being adequately protected from the mixture of contaminants released into it. In the field of environmental radioactivity, tools have been developed to assess the impacts of ionising radiation on wildlife. The scientific data upon which these assessments are based is, however, lacking. New documentation has been produced by the UK Environment Agency to provide guidelines on structuring experiments (using environmentally relevant doses) and select suitable non-human species and endpoints for study. It is anticipated that this documentation will be used to direct future experiments in this field. This paper presents the results of the first of these experiments. Numbers of the earthworm Eisenia fetida and the wood louse Porcellio scaber were segregated and constantly exposed to one of six radiation doses (background, 0.1, 0.4, 1.5, 4.0 and 8.0 mGyh{sup -1}) for a total of 16 and 14 weeks respectively. The endpoints of mortality, number of viable offspring and average weight of an individual were recorded and the results of this study will be discussed here. (author)

  13. Effect of penetrating ionising radiation on the mechanical properties of pericardium

    Energy Technology Data Exchange (ETDEWEB)

    Daar, Eman, E-mail: e.daar@surrey.ac.u [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Woods, E. [Royal Free Hampstead NHS Trust, Pond Street, Hampstead, London NW3 2QG (United Kingdom); Keddie, J.L. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Nisbet, A. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Royal Surrey County Hospital, Guildford (United Kingdom); Bradley, D.A. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom)

    2010-07-21

    The pericardium is an anistropic composite material made up of collagen and elastin fibres embedded in an amorphous matrix mainly composed of proteoglycan and hyaluronan. The collagen fibres are arranged in layers, with different directions of alignment in each layer, giving rise to interesting mechanical properties of pericardium, including the ability to undergo large deformation during performance of regular physiological functions. The present study aims to investigate the effect of penetrating photon ionising radiation on bovine pericardium tissue, being part of a study of the effect of cardiac doses received in breast radiotherapy and the possibility that this can give rise to cardiovascular complications. Irradiation doses in the range 5-80 Gy were used. To characterise the various mechanical properties [elastic modulus, stress relaxation, ultimate tensile strength (UTS) and fracture] a uniaxial tensile test method was applied. The preliminary results reflect the wide inter-sample variations that are expected in dealing with tissues, with only a weak indication of increase in the UTS of the pericardium tissue with increase in radiation dose. Such an effect has also been observed by others, with reduction in UTS at doses of 80 Gy.

  14. The Assessment of DNA Damage in Poultry Spermatozoa after Exposure to Low Doses of Ionising Radiation

    International Nuclear Information System (INIS)

    Kasuba, V.; Milic, M.; Pejakovic Hlede, J.; Gottstein, Z.; Karadjole, M.; Miljanic, S.

    2013-01-01

    The existence of dose-related induction of DNA strand breaks in spermatozoa following in vitro exposure to ionising radiation represents sperm DNA integrity as an important parameter in the evaluation of semen functionality. Maintaining of normal sperm becomes even more important when it is known that DNA in semen samples is already fragmentated in certain amount in human and turkey semen and that it lacks DNA repair mechanisms making DNA damage irreversible. The aim of this paper was to provide an insight in the amount of DNA damage detected in chicken spermatozoa (5 cocks, 45 weeks old) of heavy line after radiation with doses of 0.3, 0.5, 1 and 2 Gy gamma radiation and to address the question of the potential ecological consequences of the damage that was measured with comet assay. Scored parameters included tail intensity, tail length and tail moment. Results showed sensitivity of comet assay technique that detected significant DNA damage even after exposure to 0.3 Gy, but also showed no dose-related responses after 0.5, 1 and 2 Gy. Distribution of damaged cells was widely spread for the higher doses, showing the influence of possible adaptive response, but for further conclusions, larger studies are needed to answer that question.(author)

  15. Cancer mortality risk of nuclear power workers due to the exposure of ionising radiation in Germany

    Energy Technology Data Exchange (ETDEWEB)

    Fehringer, F.; Seitz, G. [Berufsgenossenschaft der Feinmechanik und Elektrotechnik, Koln (Germany); Hammer, G.P.; Blettner, M. [Johannes Gutenberg-Universitat Mainz, Institut fur Medizinische Biometrie, Epidemiologie und Informatik des Klinikums (Germany)

    2006-07-01

    A cohort study of German nuclear power workers was set up to investigate overall and cancer mortality risk related to a chronic exposure to ionising radiation of low-level dose. The German study was performed as a part of an international study carried out by the International Agency for Research on Cancer (IARC), Lyon. First results of the international study have been published recently [1]. German data are not yet included in this analysis. The German cohort consists of 4844 employees from 10 nuclear power plants. All persons who worked in these nuclear power plants in 1991 or started employment between 1991 und 1997 are included (except for employees of one plant, whose observation period started in 1992). These persons accumulated about 31,000 person years. Overall, 68 deaths were observed in the observation period between 1.1.1991-31.12.1997. Standardized mortality ratios (SMR) were computed for all causes of death, all cancers, cardiovascular diseases, external causes, and all other causes. Overall, a strong healthy worker effect was observed (SMR=0.52 [95% CI: 0.41;0.67]). No increase in total cancer mortality was seen (SMR=0.85 [95% CI: 0.53;1.30]). However, numbers are too small for stable risk estimates and further effort is under way to complete the cohort in terms of power plants and to extend the follow-up until 2005. (authors)

  16. Application of positive mode atmospheric chemical ionisation to distinguish epimeric oleanolic and ursolic acids.

    Science.gov (United States)

    Townley, Chloe; Brettell, Rhea C; Bowen, Richard D; Gallagher, Richard T; Martin, William H C

    2015-01-01

    A new and more reliable method is reported for distinguishing the equatorial and axial epimers of oleanolic and ursolic acids and related triterpenoids based primarily on the relative abundance of the [M+H](+) and [M+-H(2)O](+) signals in their positive mode atmospheric pressure chemical ionisation mass spectra. The rate of elimination of water, which is the principal primary fragmentation of protonated oleanolic and ursolic acids, depends systematically on the stereochemistry of the hydroxyl group in the 3 position. For the b-epimer, in which the 3-hydroxyl substituent is in an equatorial position,[M+-H(2)O](+) is the base peak. In contrast, for the α-epimer, where the 3-hydroxyl group is axial, [M + H](+) is the base peak. This trend, which is general for a range of derivatives of oleanolic and ursolic acids, including the corresponding methyl esters, allows epimeric triterpenoids in these series to be securely differentiated. Confirmatory information is available from the collision-induced dissociation of the [M+-H(2)O](+) primary fragment ions, which follow different pathways for the species derived from axial and equatorial epimers of oleanolic and ursolic acids. These two pieces of independent spectral information permit the stereochemistry of epimeric oleanolic and ursolic acids (and selected derivatives) to be assigned with confidence without relying either on chromatographic retention times or referring to the spectra or other properties of authentic samples of these triterpenoids.

  17. A gas ionisation Direct-STIM detector for MeV ion microscopy

    International Nuclear Information System (INIS)

    Norarat, Rattanaporn; Guibert, Edouard; Jeanneret, Patrick; Dellea, Mario; Jenni, Josef; Roux, Adrien; Stoppini, Luc; Whitlow, Harry J.

    2015-01-01

    Direct-Scanning Transmission Ion Microscopy (Direct-STIM) is a powerful technique that yields structural information in sub-cellular whole cell imaging. Usually, a Si p-i-n diode is used in Direct-STIM measurements as a detector. In order to overcome the detrimental effects of radiation damage which appears as a broadening in the energy resolution, we have developed a gas ionisation detector for use with a focused ion beam. The design is based on the ETH Frisch grid-less off-axis Geiger–Müller geometry. It is developed for use in a MeV ion microscope with a standard Oxford Microbeams triplet lens and scanning system. The design has a large available solid angle for other detectors (e.g. proton induced fluorescence). Here we report the performance for imaging ReNcells VM with μm resolution where energy resolutions of <24 keV fwhm could be achieved for 1 MeV protons using isobutane gas

  18. Genotoxicity in earthworm after combined treatment of ionising radiation and mercury

    International Nuclear Information System (INIS)

    Ryu, Tae Ho; Kim, Jin Kyu; An, Kwang-Guk

    2014-01-01

    This study was performed to investigate the acute genotoxic effects of mercury and radiation on earthworms (Eisenia fetida). The levels of DNA damage and the repair kinetics in the coelomocytes of E. fetida treated with mercuric chloride (HgCl 2 ) and ionising radiation (gamma rays) were analysed by means of the comet assay. For detection of DNA damage and repair, E. fetida was exposed to HgCl 2 (0-160 mg kg -1 ) and irradiated with gamma rays (0-50 Gy) in vivo. The increase in DNA damage depended on the concentration of mercury or dose of radiation. The results showed that the more the oxidative stress induced by mercury and radiation the longer the repair time that was required. When a combination of HgCl 2 and gamma rays was applied, the cell damage was much higher than those treated with HgCl 2 or radiation alone, which indicated that the genotoxic effects were increased after the combined treatment of mercury and radiation. (authors)

  19. Analysis of e-e angular correlations in near-threshold electron impact ionisation of helium

    International Nuclear Information System (INIS)

    Selles, P.; Huetz, A.; Mazeau, J.

    1987-01-01

    Using a coincidence technique in a coplanar geometry, triple differential cross sections (TDCS) for electron impact ionisation of helium are measured in the 0.5-2 eV energy range above threshold. As a few states (O <= L <= 2) of the two outgoing electrons are obviously involved in the process, their respective intensities appear as unknown parameters in the theoretical TDCS as deduced in the frame of the Wannier theory. The authors show that almost all these parameters can be determined through normalisation to the measured TDCS in two specific geometries: in the first one the two electrons are kept in opposite directions while in the second one they remain symmetrical with respect to the incident beam. A comparison with the complete set of data is then performed. The measured TDCS are in agreement with the Wannier theory for the lowest energies (0.5 and 1 eV). At 2 eV the overall agreement becomes poorer, although some predictions of the Wannier theory still apply. Finally specific measurements at 8 eV clearly show from consideration of symmetry that the Wannier theory no longer applies at this energy. (author)

  20. Gene expression analysis after low dose ionising radiation exposure of the developing organism

    International Nuclear Information System (INIS)

    Abderrafi Benotmane, M.

    2007-01-01

    Measuring gene expression using microarrays is relevant to many areas of biology and medicine, such as follow up of developmental stages and diseases onset, and treatment study. Since there can be tens of thousands of distinct probes on an array, each micro array experiment can accomplish the equivalent number of genetic tests in parallel. Arrays have therefore dramatically accelerated many types of investigations. For example, microarrays can be used to identify stress response genes by comparing gene expression in challenged versus normal cells. In the Molecular and Cellular Biology lab (MCB), the micro array experiments are performed within the Genomic Platform, fully equipped to analyse either the behaviour of bacteria during long space flight, the effect of low dose ionising radiation on the developing organism in mice, or the human individual radiation sensitivity. For the low dose effect, two main stages of development are of interest; 1) the gastrula stage at which ionizing radiation can induce several malformations. 2) the organogenesis. During brain development, epidemiological studies of the atomic bomb survivors of Hiroshima/Nagasaki showed increased risk of mental retardation in children of women exposed between weeks 8-15 of pregnancy or at a lower extend between weeks 15 to 25

  1. Genomic instability in rat: Breakpoints induced by ionising radiation and interstitial telomeric-like sequences

    International Nuclear Information System (INIS)

    Camats, Nuria; Ruiz-Herrera, Aurora; Parrilla, Juan Jose; Acien, Maribel; Paya, Pilar; Giulotto, Elena; Egozcue, Josep; Garcia, Francisca; Garcia, Montserrat

    2006-01-01

    The Norwegian rat (Rattus norvegicus) is the most widely studied experimental species in biomedical research although little is known about its chromosomal structure. The characterisation of possible unstable regions of the karyotype of this species would contribute to the better understanding of its genomic architecture. The cytogenetic effects of ionising radiation have been widely used for the study of genomic instability, and the importance of interstitial telomeric-like sequences (ITSs) in instability of the genome has also been reported in previous studies in vertebrates. In order to describe the unstable chromosomal regions of R. norvegicus, the distribution of breakpoints induced by X-irradiation and ITSs in its karyotype were analysed in this work. For the X-irradiation analysis, 52 foetuses (from 14 irradiated rats) were studied, 4803 metaphases were analysed, and a total of 456 breakpoints induced by X-rays were detected, located in 114 chromosomal bands, with 25 of them significantly affected by X-irradiation (hot spots). For the analysis of ITSs, three foetuses (from three rats) were studied, 305 metaphases were analysed and 121 ITSs were detected, widely distributed in the karyotype of this species. Seventy-six percent of all hot spots analysed in this study were co-localised with ITSs

  2. Genomic instability in rat: Breakpoints induced by ionising radiation and interstitial telomeric-like sequences

    Energy Technology Data Exchange (ETDEWEB)

    Camats, Nuria [Institut de Biotecnologia i Biomedicina (IBB), Universitat Autonoma de Barcelona, 08193 Barcelona (Spain); Departament de Biologia Cel.lular, Fisiologia i Immunologia Universitat Autonoma de Barcelona, 08193 Barcelona (Spain); Ruiz-Herrera, Aurora [Departament de Biologia Cel.lular, Fisiologia i Immunologia Universitat Autonoma de Barcelona, 08193 Barcelona (Spain); Parrilla, Juan Jose [Servicio de Ginecologia y Obstetricia, Hospital Universitario Virgen de la Arrixaca, Ctra, Madrid-Cartagena, s/n, El Palmar, 30120 Murcia (Spain); Acien, Maribel [Servicio de Ginecologia y Obstetricia, Hospital Universitario Virgen de la Arrixaca, Ctra, Madrid-Cartagena, s/n, El Palmar, 30120 Murcia (Spain); Paya, Pilar [Servicio de Ginecologia y Obstetricia, Hospital Universitario Virgen de la Arrixaca, Ctra, Madrid-Cartagena, s/n, El Palmar, 30120 Murcia (Spain); Giulotto, Elena [Dipartimento di Genetica e Microbiologia Adriano Buzzati Traverso, Universita degli Studi di Pavia, 27100 Pavia (Italy); Egozcue, Josep [Departament de Biologia Cel.lular, Fisiologia i Immunologia Universitat Autonoma de Barcelona, 08193 Barcelona (Spain); Garcia, Francisca [Institut de Biotecnologia i Biomedicina (IBB), Universitat Autonoma de Barcelona, 08193 Barcelona (Spain); Garcia, Montserrat [Institut de Biotecnologia i Biomedicina (IBB), Universitat Autonoma de Barcelona, 08193 Barcelona (Spain) and Departament de Biologia Cellular, Fisiologia i Immunologia Universitat Autonoma de Barcelona, 08193 Barcelona (Spain)]. E-mail: Montserrat.Garcia.Caldes@uab.es

    2006-03-20

    The Norwegian rat (Rattus norvegicus) is the most widely studied experimental species in biomedical research although little is known about its chromosomal structure. The characterisation of possible unstable regions of the karyotype of this species would contribute to the better understanding of its genomic architecture. The cytogenetic effects of ionising radiation have been widely used for the study of genomic instability, and the importance of interstitial telomeric-like sequences (ITSs) in instability of the genome has also been reported in previous studies in vertebrates. In order to describe the unstable chromosomal regions of R. norvegicus, the distribution of breakpoints induced by X-irradiation and ITSs in its karyotype were analysed in this work. For the X-irradiation analysis, 52 foetuses (from 14 irradiated rats) were studied, 4803 metaphases were analysed, and a total of 456 breakpoints induced by X-rays were detected, located in 114 chromosomal bands, with 25 of them significantly affected by X-irradiation (hot spots). For the analysis of ITSs, three foetuses (from three rats) were studied, 305 metaphases were analysed and 121 ITSs were detected, widely distributed in the karyotype of this species. Seventy-six percent of all hot spots analysed in this study were co-localised with ITSs.

  3. The study of some thiazinic and indaminic dye syntheses induced by ionising radiation

    International Nuclear Information System (INIS)

    Balestic, S.

    1961-03-01

    With a view to finding some radiochemical reactions applicable on an industrial scale for evaluating the radioactive waste from nuclear reactors, a systematic study was made of the radiochemical synthesis of thiazinic dyes such as methylene blue and Lauths' violet, on which the first tests were carried out in 1954. The first part of the study concerned the identification and the dosage, during radiolysis, of dyes by means of their absorption spectra after separation from the reaction medium by adsorption chromatography or ion-exchange; other radiolysis products such as ammonium chloride and hydrogen peroxide were also identified. During a later stage by systematically varying the physico-chemical parameters it was possible to determine the most favourable conditions for radio-synthesis; the maximum radiochemical yields obtained had the following values: G (Lauths' violet) 1,65; G (Methylene blue) = 1,75. Furthermore, the study of the influence of variously substituted aminated products on the radiochemical yield showed the possibility of synthesising Bindsehedlers green and Wursters blue by radiochemical methods. Finally the discovery of a fundamental intermediate product, Wursters red, together with the kinetic study of the chemical synthesis of methylene blue made it possible to determine the main stages of the reaction mechanism and to decide which of these stages could be attributed to ionising radiations in the case of the radiochemical synthesis. (author) [fr

  4. The risk of low doses of ionising radiation and the linear no threshold relationship debate

    International Nuclear Information System (INIS)

    Tubiana, M.; Masse, R.; Vathaire, F. de; Averbeck, D.; Aurengo, A.

    2007-01-01

    The ICRP and the B.E.I.R. VII reports recommend a linear no threshold (L.N.T.) relationship for the estimation of cancer excess risk induced by ionising radiations (IR), but the 2005 report of Medicine and Science French Academies concludes that it leads to overestimate of risk for low and very low doses. The bases of L.N.T. are challenged by recent biological and animal experimental studies which show that the defence against IR involves the cell microenvironment and the immunologic system. The defence mechanisms against low doses are different and comparatively more effective than for high doses. Cell death is predominant against low doses. DNA repairing is activated against high doses, in order to preserve tissue functions. These mechanisms provide for multicellular organisms an effective and low cost defence system. The differences between low and high doses defence mechanisms are obvious for alpha emitters which show several greys threshold effects. These differences result in an impairment of epidemiological studies which, for statistical power purpose, amalgamate high and low doses exposure data, since it would imply that cancer IR induction and defence mechanisms are similar in both cases. Low IR dose risk estimates should rely on specific epidemiological studies restricted to low dose exposures and taking precisely into account potential confounding factors. The preliminary synthesis of cohort studies for which low dose data (< 100 mSv) were available show no significant risk excess, neither for solid cancer nor for leukemias. (authors)

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

    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.

  6. Performance characteristics of a Bioassay method for plutonium using thermal ionisation mass spectrometry (TIMS)

    Energy Technology Data Exchange (ETDEWEB)

    Linauskas, S.H.; Elliot, N.L.; Paterson, L.M.; Totland, M.M

    2003-01-01

    Plutonium-in-urine analysis by radiochemical isolation of Pu followed by thermal ionisation mass spectrometry (TIMS) is capable of high sensitivity and precision measurements {sup 239}Pu and {sup 240}Pu. Bias and precision estimates for the TIMS bioassay program at Chalk River Laboratories easily met the ANSI N13.30 performance criteria standards with {sup 239}Pu results of 1.5% and 3.0%, respectively. Analytical blanks derived from water, artificial urine and true urine samples did not produce any statistically different results. During a four-year period of development and implementation of {sup 239}Pu measurements by TIMS, average sample blank values were reduced from 3.9 fg (9.0 {mu}Bq) to 0.57 fg (1.3 {mu}Bq). This reduction was achieved through rigorous application of clean-room handling techniques throughout sample processing. Blank data were found to follow a Iognormal distribution, and current detection limit parameters for L{sub c} and L{sub d} at the 95% significance levels are 0.85 fg {sup 239}Pu (2.0 {mu}Bq) and 1.3 fg {sup 239}Pu (3.0 {mu}Bq), respectively. Detection limits in this range are expected to be sufficient to identify intakes of Pu/Am mixtures at levels that are around one-twentieth of an ALl or better under routine monitoring situations for ICRP Type S and Type M inhalation solubility classes. (author)

  7. Law on protection against ionising radiation and nuclear safety in Slovenia

    International Nuclear Information System (INIS)

    Breznik, B.; Krizman, M.; Skrk, D.; Tavzes, R.

    2003-01-01

    The existing legislation related to nuclear and radiation safety in Slovenia was introduced in 80's. The necessity for the new law is based on the new radiation safety standards (ICRP 60) and the intention of Slovenia to harmonize the legislation with the European Union. The harmonization means adoption of the basic safety standards and other relevant directives and regulations of Euratom. The nuclear safety section of this law is based on the legally binding international conventions ratified by Slovenia. The general approach is similar to that of some members of Nuclear Energy Agency (OECD). The guidelines of the law were set by the Ministry of the Environment and Spatial Planning, Nuclear Safety Administration, and Ministry of Health. The expert group of the Ministry of Environment and Spatial Planning and the Ministry of Health together with the representatives of the users of the ionising sources and representatives of the nuclear sector, prepared the draft of the subject law. The emphasis in this paper is given to main topics and solutions related to the control of the occupationally exposed workers, radiation safety, licensing, nuclear and waste safety, and radiation protection of people and patients. (authors)

  8. A special ionisation chamber for quality control of diagnostic and mammography X ray equipment

    International Nuclear Information System (INIS)

    Costa, A.M.; Caldas, L.V.E.

    2003-01-01

    A quality control program for X ray equipment used for conventional radiography and mammography requires the constancy check of the beam qualities in terms of the half-value layers. In this work, a special double-faced parallel-plate ionisation chamber was developed with inner electrodes of different materials, in a tandem system. Its application will be in quality control programs of diagnostic and mammography X ray equipment for confirmation of half-value layers previously determined by the conventional method. Moreover, the chamber also may be utilised for measurements of air kerma values (and air kerma rates) in X radiation fields used for conventional radiography and mammography. The chamber was studied in relation to the characteristics of saturation, ion collection efficiency, polarity effects, leakage current, and short-term stability. The energy dependence in response of each of the two faces of the chamber was determined over the conventional radiography and mammography X ray ranges (unattenuated beams). The different energy responses of the two faces of the chamber allowed the formation of a tandem system useful for the constancy check of beam qualities. (author)

  9. A special ionisation chamber for quality control of diagnostic and mammography X ray equipment.

    Science.gov (United States)

    Costa, A M; Caldas, L V E

    2003-01-01

    A quality control program for X ray equipment used for conventional radiography and mammography requires the constancy check of the beam qualities in terms of the half-value layers. In this work, a special double-faced parallel-plate ionisation chamber was developed with inner electrodes of different materials, in a tandem system. Its application will be in quality control programs of diagnostic and mammography X ray equipment for confirmation of half-value layers previously determined by the conventional method. Moreover, the chamber also may be utilised for measurements of air kerma values (and air kerma rates) in X radiation fields used for conventional radiography and mammography. The chamber was studied in relation to the characteristics of saturation, ion collection efficiency, polarity effects, leakage current, and short-term stability. The energy dependence in response of each of the two faces of the chamber was determined over the conventional radiography and mammography X ray ranges (unattenuated beams). The different energy response of the two faces of the chamber allowed the formation of a tandem system useful for the constancy check of beam qualities.

  10. Revisiting Bragg's X-ray microscope: Scatter based optical transient grating detection of pulsed ionising radiation

    International Nuclear Information System (INIS)

    Fullagar, Wilfred K.; Paganin, David M.; Hall, Chris J.

    2011-01-01

    Transient optical gratings for detecting ultrafast signals are routine for temporally resolved photochemical investigations. Many processes can contribute to the formation of such gratings; we indicate use of optically scattering centres that can be formed with highly variable latencies in different materials and devices using ionising radiation. Coherent light scattered by these centres can form the short-wavelength-to-optical-wavelength, incoherent-to-coherent basis of a Bragg X-ray microscope, with inherent scope for optical phasing. Depending on the dynamics of the medium chosen, the way is open to both ultrafast pulsed and integrating measurements. For experiments employing brief pulses, we discuss high-dynamic-range short-wavelength diffraction measurements with real-time optical reconstructions. Applications to optical real-time X-ray phase-retrieval are considered. -- Research highlights: → It is timely that the concept of Bragg's X-ray microscope be revisited. → Transient gratings can be used for X-ray all-optical information processing. → Applications to optical real-time X-ray phase-retrieval are considered.

  11. Steam torch plasma modelling

    Czech Academy of Sciences Publication Activity Database

    Jeništa, Jiří

    2017-01-01

    Roč. 37, č. 3 (2017), s. 653-687 ISSN 0272-4324 R&D Projects: GA ČR(CZ) GA15-19444S Institutional support: RVO:61389021 Keywords : Arc * Evaporation * Mass flow rate * Water-vortex stabilization * Net emission coefficients * Partial characteristics * Local thermodynamic equilibrium Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 2.355, year: 2016 http://link.springer.com/article/10.1007/s11090-017-9789-7

  12. Scattering characteristics of electromagnetic waves in time and space inhomogeneous weakly ionized dusty plasma sheath

    Science.gov (United States)

    Guo, Li-xin; Chen, Wei; Li, Jiang-ting; Ren, Yi; Liu, Song-hua

    2018-05-01

    The dielectric coefficient of a weakly ionised dusty plasma is used to establish a three-dimensional time and space inhomogeneous dusty plasma sheath. The effects of scattering on electromagnetic (EM) waves in this dusty plasma sheath are investigated using the auxiliary differential equation finite-difference time-domain method. Backward radar cross-sectional values of various parameters, including the dust particle radius, charging frequency of dust particles, dust particle concentration, effective collision frequency, rate of the electron density variation with time, angle of EM wave incidence, and plasma frequency, are analysed within the time and space inhomogeneous plasma sheath. The results show the noticeable effects of dusty plasma parameters on EM waves.

  13. Characterisation of Plasma Vitrified Simulant Plutonium Contaminated Material Waste

    International Nuclear Information System (INIS)

    Hyatt, Neil C.; Morgan, Suzy; Stennett, Martin C.; Scales, Charlie R.; Deegan, David

    2007-01-01

    The potential of plasma vitrification for the treatment of a simulant Plutonium Contaminated Material (PCM) was investigated. It was demonstrated that the PuO 2 simulant, CeO 2 , could be vitrified in the amorphous calcium iron aluminosilicate component of the product slag with simultaneous destruction of the organic and polymer waste fractions. Product Consistency Tests conducted at 90 deg. C in de-ionised water and buffered pH 11 solution show the PCM slag product to be durable with respect to release of Ce. (authors)

  14. Partial differential equations and their applications

    International Nuclear Information System (INIS)

    Gauthier-Villars

    1998-01-01

    This book is dedicated to the French mathematician J.L.Lions. It represents a compilation of articles from about 80 authors. The topics treated are diverse but the more or less commune matter is the study of the characteristics of some partial differential equations. Stability, optimal approximation, numerical resolution, particular applications are among the subjects reviewed. An article deals with the MHD stability of fusion plasmas in tokamaks, another presents the scientific and technical challenges of nuclear energy in France. The latter that contains no equations can be considered as an enjoyable break in a sea of about 40 mathematical articles. (A.C.)

  15. Partially ordered algebraic systems

    CERN Document Server

    Fuchs, Laszlo

    2011-01-01

    Originally published in an important series of books on pure and applied mathematics, this monograph by a distinguished mathematician explores a high-level area in algebra. It constitutes the first systematic summary of research concerning partially ordered groups, semigroups, rings, and fields. The self-contained treatment features numerous problems, complete proofs, a detailed bibliography, and indexes. It presumes some knowledge of abstract algebra, providing necessary background and references where appropriate. This inexpensive edition of a hard-to-find systematic survey will fill a gap i

  16. Infinite partial summations

    International Nuclear Information System (INIS)

    Sprung, D.W.L.

    1975-01-01

    This paper is a brief review of those aspects of the effective interaction problem that can be grouped under the heading of infinite partial summations of the perturbation series. After a brief mention of the classic examples of infinite summations, the author turns to the effective interaction problem for two extra core particles. Their direct interaction is summed to produce the G matrix, while their indirect interaction through the core is summed in a variety of ways under the heading of core polarization. (orig./WL) [de

  17. On universal partial words

    OpenAIRE

    Chen, Herman Z. Q.; Kitaev, Sergey; Mütze, Torsten; Sun, Brian Y.

    2016-01-01

    A universal word for a finite alphabet $A$ and some integer $n\\geq 1$ is a word over $A$ such that every word in $A^n$ appears exactly once as a subword (cyclically or linearly). It is well-known and easy to prove that universal words exist for any $A$ and $n$. In this work we initiate the systematic study of universal partial words. These are words that in addition to the letters from $A$ may contain an arbitrary number of occurrences of a special `joker' symbol $\\Diamond\

  18. Partial differential equations

    CERN Document Server

    Agranovich, M S

    2002-01-01

    Mark Vishik's Partial Differential Equations seminar held at Moscow State University was one of the world's leading seminars in PDEs for over 40 years. This book celebrates Vishik's eightieth birthday. It comprises new results and survey papers written by many renowned specialists who actively participated over the years in Vishik's seminars. Contributions include original developments and methods in PDEs and related fields, such as mathematical physics, tomography, and symplectic geometry. Papers discuss linear and nonlinear equations, particularly linear elliptic problems in angles and gener

  19. Partial differential equations

    CERN Document Server

    Levine, Harold

    1997-01-01

    The subject matter, partial differential equations (PDEs), has a long history (dating from the 18th century) and an active contemporary phase. An early phase (with a separate focus on taut string vibrations and heat flow through solid bodies) stimulated developments of great importance for mathematical analysis, such as a wider concept of functions and integration and the existence of trigonometric or Fourier series representations. The direct relevance of PDEs to all manner of mathematical, physical and technical problems continues. This book presents a reasonably broad introductory account of the subject, with due regard for analytical detail, applications and historical matters.

  20. Partial differential equations

    CERN Document Server

    Sloan, D; Süli, E

    2001-01-01

    /homepage/sac/cam/na2000/index.html7-Volume Set now available at special set price ! Over the second half of the 20th century the subject area loosely referred to as numerical analysis of partial differential equations (PDEs) has undergone unprecedented development. At its practical end, the vigorous growth and steady diversification of the field were stimulated by the demand for accurate and reliable tools for computational modelling in physical sciences and engineering, and by the rapid development of computer hardware and architecture. At the more theoretical end, the analytical insight in