WorldWideScience

Sample records for accelerator produced nuclides

  1. Accelerator produced nuclides for use in biology and medicine. A bibliography, 1939--1973

    A bibliography of more than 1300 references on accelerator-produced nuclides for use in biology and medicine is presented. The information is arranged by subject and by specific nuclide. An author index is included. Appendices are provided of medical uses of specific elements and of radioisotopes not included in the main bibliography. (U.S.)

  2. Accelerator produced nuclides for use in biology and medicine. A bibliography: January 1974--June 1976

    This bibliography (Volume II) follows the format of the first bibliography. Nuclides used therapeutically have not been included. References to medical application of the various nuclides of iodine, gallium, and indium have been excluded as being beyond the scope of this bibliography (and to keep its size to manageable proportions). For nuclides having fifteen or fewer references there is no breakdown into subcategories. For the others they have been subdivided as follows: (1) Production methods, (2) Compound syntheses, and (3) Medical uses. The first part of the bibliography contains references of general interest of various types. Where specific nuclides are involved, these references are also cross-indexed to each nuclide. The original reference number is always used for cross-indexing. The nuclide section is arranged in alphabetical order, and within each section alphabetically by first author. The author index lists each reference once for each author, with no indication of cross-referencing given

  3. An introduction to in-situ produced cosmogenic nuclides

    Cosmogenic nuclides are produced through interactions between cosmic rays and target nuclei in Earth's atmosphere and surface materials. Those which are produced in Earth's atmosphere are termed 'meteoric' while the nuclides produced in surface material are known as in-situ cosmogenic nuclides. The past two decades have seen a proliferation of applications for cosmogenic nuclides. This is primarily due to a revolution in accelerator mass spectrometry, AMS, measurement techniques which has allowed the measurement of very small amounts of nuclides. The following is a brief introduction to the theory and application of in-situ produced cosmogenic nuclide methods. (author). 17 refs., figs., 1 tab.

  4. Determination of nuclide inventories in accelerator radwaste

    In switzerland, the location of two of the largest accelerator facilities, CERN and PSI, the authorities requested for a valuation of the radionuclide inventories in accelerator radwaste. In the first phase, model calculations should be verified by radioanalytical analyses. At PSI, the radioactive contents were measured after a careful chemical separation, by γ-spectrometry, α-spectrometry, low-level counting and accelerator mass spectrometry, respectively. Examples: (i) The copper beam dump of target E was analyzed; its activities were in the range between 1.107 Bq/g for 60Co and 1.10-5 Bq/g for 60Fe. (ii) In shielding concrete, more than 30 mBq/g 239,240Pu were found which is higher than the exemption limit. (iii) In graphite targets, at end of bombardment 2.1011 Bq/g 7Be were detected. (iv) In an Eu project, the know-how of the radiochemical separation procedures was used for determination of transmutation-relevant nuclear reaction cross sections. (orig.)

  5. WebCN: A web-based computation tool for in situ-produced cosmogenic nuclides

    Cosmogenic nuclide techniques are increasingly being utilized in geoscience research. For this it is critical to establish an effective, easily accessible and well defined tool for cosmogenic nuclide computations. We have been developing a web-based tool (WebCN) to calculate surface exposure ages and erosion rates based on the nuclide concentrations measured by the accelerator mass spectrometry. WebCN for 10Be and 26Al has been finished and published at http://www.physics.purdue.edu/primelab/for_users/rockage.html. WebCN for 36Cl is under construction. WebCN is designed as a three-tier client/server model and uses the open source PostgreSQL for the database management and PHP for the interface design and calculations. On the client side, an internet browser and Microsoft Access are used as application interfaces to access the system. Open Database Connectivity is used to link PostgreSQL and Microsoft Access. WebCN accounts for both spatial and temporal distributions of the cosmic ray flux to calculate the production rates of in situ-produced cosmogenic nuclides at the Earth's surface

  6. Simulation of experimental spectra for medium-heavy nuclides in accelerator mass spectrometry

    WANG Hui-Juan; GUAN Yong-Jing; HE Ming; RUAN Xiang-Dong; DONG Ke-Jun; LI Guo-Qiang; Wu Shao-Yong; WU Wei-Ming; JIANG Shan

    2005-01-01

    Some interferences are often encountered in accelerator mass spectrometry (AMS) measurements, especially for medium-heavy nuclide measurement. It is difficult for online discrimination of the nuclide of interest from the interfering ones. In order to solve this problem, we developed a method to simulate the experimental spectra of medium-heavy nuclides in AMS measurements. The results obtained from this method are in good agreement with experimental values.

  7. Analysis of the total activation cross section of all possible reactions producing the same radioactive nuclide for the%Analysis of the total activation cross section of all possible reactions producing the same radioactive nuclide for the

    周丰群; 宋月丽; 拓飞; 孔祥忠

    2011-01-01

    Firstly, according to the regulation of growth and decay of radioactive nuclides produced in reactions, a formula used to calculate the total activation cross section of all possible reactions producing the same radioactive nuclide for the same element is

  8. Cosmogenic neutron-capture-produced nuclides in stony meteorites

    The distribution of neutrons with energies below 15 MeV in spherical stony meteoroids is calculated using the ANISN neutron-transport code. The source distributions and intensities of neutrons are calculated using cross sections for the production of tritium. The meteoroid's radius and chemical composition strongly influence the total neutron flux and the neutron energy spectrum, while the location within a meteoroid only affects the relative neutron intensities. Meteoroids need to have radii of more than 50 g/cm2 before they have appreciable fluxes of neutrons near thermal energies. Meteoroids with high hydrogen or low iron contents can thermalize neutrons better than chondrites. Rates for the production of 60Co, 59Ni, and 36Cl are calculated with evaluated neutron-capture cross sections and neutron fluxes determined for carbonaceous chondrites with high hydrogen contents, L-chondrites, and aubrites. For most meteoroids with radii 2, the production rates of these neutron-capture nuclides increase monotonically with depth. The highest calculated 60Co production rate in an ordinary chondrite is 375 atoms/(min g-Co) at the center of a meteoroid with a 250 g/cm2 radius. The production rates calculated for spallogenic 60Co and 59Ni are greater than the neutron-capture rates for radii less than approx.50-75 g/cm2. Only for very large meteoroids and chlorine-rich samples is the neutron-capture production of 36Cl important. The results of these calculations are compared with those of previous calculations and with measured activities in many meteorites. 44 refs., 15 figs., 1 tab

  9. Study of the acceleration of nuclide burnup calculation using GPU with CUDA

    The computation costs of neutronics calculation code become higher as physics models and methods are complicated. The degree of them in neutronics calculation tends to be limited due to available computing power. In order to open a door to the new world, use of GPU for general purpose computing, called GPGPU, has been studied [1]. GPU has multi-threads computing mechanism enabled with multi-processors which realize mush higher performance than CPUs. NVIDIA recently released the CUDA language for general purpose computation which is a C-like programming language. It is relatively easy to learn compared to the conventional ones used for GPGPU, such as OpenGL or CG. Therefore application of GPU to the numerical calculation became much easier. In this paper, we tried to accelerate nuclide burnup calculation, which is important to predict nuclides time dependence in the core, using GPU with CUDA. We chose the 4.-order Runge-Kutta method to solve the nuclide burnup equation. The nuclide burnup calculation and the 4.-order Runge-Kutta method were suitable to the first step of introduction CUDA into numerical calculation because these consist of simple operations of matrices and vectors of single precision where actual codes were written in the C++ language. Our experimental results showed that nuclide burnup calculations with GPU have possibility of speedup by factor of 100 compared to that with CPU. (authors)

  10. Accelerator experiments on the contribution of secondary particles to the production of cosmogenic nuclides in meteorites

    Englert, P.; Dragovitsch, P.

    1985-01-01

    Through the interaction of galactic cosmic particle radiation (GCR) a wide variety of cosmogenic nuclides is produced in meteorites. They provide historical information about the cosmic radiation and the bombarded meteorites. An important way to understand the production mechanisms of cosmogenic nuclides in meteorites is to gather information about the depth and size dependence of the build-up of Galactic Rays Cosmic-secondary particles within meteorites of different sizes and chemical compositions. Simulation experiments with meteorite models offer an alternative to direct observation providing a data basis to describe the development and action of the secondary cascade induced by the GCR in meteorites.

  11. Activation cross-section measurement of a sort of nuclide produced with a target including two isotopes

    ZHOU Feng-Qun; TIAN Ming-Li; SONG Yue-Li; LAN Chang-Lin; KONG Xiang-Zhong

    2013-01-01

    Based on a formula used to calculate the activation cross-section sum of two reactions producing a sort of nuclide with a target including two isotopes,the related problems in some references have been analyzed and discussed.It is pointed out that the calculation methods of the cross-section sum of two reactions producing the same radioactive nuclide for two isotopes in some references are improper and usually it is impossible to obtain the correct cross-section sum of two reactions producing the same radioactive nuclide for two isotopes in the case of using natural samples.At the same time,the related concepts are clarified and the correct processing method and representation are given.The comparison with the experimental results show that the theoretical analysis results are right.

  12. Activation cross-section measurement of a sort of nuclide produced with a target including two isotopes

    Based on a formula used to calculate the activation cross-section sum of two reactions producing a sort of nuclide with a target including two isotopes, the related problems in some references have been analyzed and discussed. It is pointed out that the calculation methods of the cross-section sum of two reactions producing the same radioactive nuclide for two isotopes in some references are improper and usually it is impossible to obtain the correct cross-section sum of two reactions producing the same radioactive nuclide for two isotopes in the case of using natural samples. At the same time, the related concepts are clarified and the correct processing method and representation are given. The comparison with the experimental results show that the theoretical analysis results are right. (authors)

  13. Estimate of the intensities of the radioactive nuclides produced at the super-FRS at the future GSI facility

    Ricciardi, M.V.

    2004-11-01

    The principal goal of the new facility is the construction of a worldwide unique and technically innovative accelerator system that will provide an extensive range of particle beams. Proton and antiproton beams will be available and ion beams of all chemical elements up to uranium will be produced with world-record intensities. The main employ of the high-intensity ion beams is the production of energetic beams of short-lived (radioactive) nuclei, in the following referred to as exotic or Rare Isotope Beams (RIBs). RIBs are produced in nuclear reactions experienced by the primary beams of stable particles. We report on the study of the production of radioactive nuclides and of their propagation through the Super-FRS. The study was performed by means of a nuclear-reaction Monte-Carlo code, ABRABLA, opportunely implemented for the above-described purpose. This work offers an overview of the radioactivity production in the Super-FRS area; the latter is the required starting knowledge for the design of the shielding structure. (orig.)

  14. Estimate of the intensities of the radioactive nuclides produced at the super-FRS at the future GSI facility

    The principal goal of the new facility is the construction of a worldwide unique and technically innovative accelerator system that will provide an extensive range of particle beams. Proton and antiproton beams will be available and ion beams of all chemical elements up to uranium will be produced with world-record intensities. The main employ of the high-intensity ion beams is the production of energetic beams of short-lived (radioactive) nuclei, in the following referred to as exotic or Rare Isotope Beams (RIBs). RIBs are produced in nuclear reactions experienced by the primary beams of stable particles. We report on the study of the production of radioactive nuclides and of their propagation through the Super-FRS. The study was performed by means of a nuclear-reaction Monte-Carlo code, ABRABLA, opportunely implemented for the above-described purpose. This work offers an overview of the radioactivity production in the Super-FRS area; the latter is the required starting knowledge for the design of the shielding structure. (orig.)

  15. Saturation condition and evolution of the nuclides for sub-critical system driven by accelerator

    At present work, under initial inventory with 232Th and natU, the evolution of nuclides in subcritical devices under given thermal, fast, hardening fast and fission neutron field are studied without the detail structure of sub-critical device and the burn-up being considered. It is supposed that the subcritical reactor consists of uniform in which the flux of neutron is homogeneous. The fissile nuclides breeding, equilibrium condition, minor activity (MA) accumulation and transmutation, are studied. (author)

  16. New approaches investigating production rates of in-situ produced terrestrial cosmogenic nuclides

    Merchel, Silke [CEREGE, CNRS-IRD-Universite Aix-Marseille, Aix-en-Provence (France); FZD, Dresden (Germany); Braucher, Regis; Benedetti, Lucilla; Bourles, Didier [CEREGE, CNRS-IRD-Universite Aix-Marseille, Aix-en-Provence (France)

    2010-07-01

    In-situ produced cosmogenic nuclides have proved to be valuable tools for environmental and Earth sciences. However, accurate application of this method is only possible, if terrestrial production rates in a certain environment over a certain time period and their depth-dependence within the exposed material are exactly known. Unfortunately, the existing data and models differ up to several tens of percent. Thus, one of the European project CRONUS-EU goals is the high quality calibration of the {sup 36}Cl production rate by spallation at independently dated surfaces. As part of fulfilling this task we have investigated calcite-rich samples from four medieval landslide areas in the Alps: Mont Granier, Le Claps, Dobratsch, and Veliki Vrh (330-1620 m, 1248-1442 AD). For investigating the depth-dependence of the different nuclear reactions, especially, the muon- and thermal neutron-induced contributions, we have analysed mixtures of carbonates and siliceous conglomerate samples - for {sup 10}Be, {sup 26}Al, and {sup 36}Cl - exposed at different shielding depths and taken from a core drilled in 2005 at La Ciotat, France (from surface to 11 m shielding). AMS of {sup 36}Cl was performed at LLNL and ETH, {sup 10}Be and {sup 26}Al at ASTER.

  17. Studies of Itokawa's Surface Exposure by Measurements of Cosmic-ray Produced Nuclides

    Caffee, M. W.; Nishiizumi, K.; Tsuchiyama, A.; Uesugi, M.; Zolensky, M. E.

    2014-01-01

    We plan to investigate the evolutionary history of surface materials from 25143 Itokawa, the Hayabusa samples. Our studies are based on the measurement of nuclides produced in asteroidal surface materials by cosmic rays. Cosmogenic radionuclides are used to determine the duration and nature of the exposure of materials to energetic particles. Our goals are to understand both the fundamental processes on the asteroidal surface and the evolutionary history of its surface materials. They are also key to understanding the history of Itokawa's surface and asteroid-meteoroid evolutionary dynamics. To achieve our key goals, in particular reconstructing the evolutionary histories of the asteroidal surface, we proposed: (1) characterizing Itokawa particles using SXCT, SXRD, and FE-SEM without modification of the sample; (2) embedding each particle in acrylic resin, then slicing a small corner with an ultra-microtome and examining it using super-STEM and SIMS for characterizing surface morphology, space weathering, and oxygen three-isotope analysis; and finally (3) measuring small amounts of cosmogenic radionuclides (104-105 atoms) in Hayabusa samples by AMS. However, we have to modify our plan due to unexpected situation.

  18. The recovery and study of heavy nuclides produced in a nuclear explosion - the Hutch event

    During the explosion of the Hutch device, the target (238U and 232Th) was subjected to a very high neutron exposure, 2.4 x 1025 neutrons /cm2. Multiple neutron capture reactions resulted in the production of heavy nuclides, up to and including 257Fm. Results of the search for species with A > 257 were negative. The recovery and chemical processing of kilograms of Hutch debris has resulted in the isolation of 1010 atoms of 257Fm, which is 102 times more material than has been available for experimentation in the past. Experimentally significant amounts of other rare nuclides, e.g., :254Cf, 251Cf, 255-Es, and 250Cm, have also been separated from the Hutch debris. The production of these nuclides in thermonuclear explosions is shown to be a valuable supplement to the AEC program for reactor production of transplutonium elements. The neutron flux achieved in Hutch was insufficient to even approach production of nuclides in the region of 298114. A much more intense neutron flux is required. In future experiments, considerable attention must be given to the problem of adequate sample recovery, in order to properly use the ability to subject targets to an exceedingly intense time-integrated neutron flux. (author)

  19. Natural Paleoseismometers: Cosmogenic Nuclide Dating of Precariously Balanced Rocks (PBRs) - Integral Constraints on Maximum Ground Accelerations

    Perg, L. A.; Ludwig, L. G.; Kendrick, K.; Brune, J.; Purvance, M.; Anooshehpoor, R.; Akciz, S.

    2007-12-01

    Precariously balanced rocks (PBRs) act as natural seismometers constraining maximum ground acceleration over the surface exposure history of the PBR. These key paleoseismic indicators have the potential to validate ground motions on the timescale necessary to test earthquake rupture forecasts and Seismic Hazard Assessment estimates, and are an active topic of research to validate CyberShake results and constrain National Seismic Hazard Maps. This research focuses on examining the post-exhumation history of PBRs using in-situ terrestrial cosmogenic nuclides (TCNs). TCNs provide a record of near-surface exposure history. The measured concentrations are a function of the residence time in the upper ~20 m of the subsurface (inherited concentration), the timing and rate of exhumation, and post-exhumation surface spalling and chemical erosion. Our goal in the project is to provide reasonable constraints on the post-exhumation history, specifically the age of the PBRs and evolution of precariousness: we should be able to constrain whether the rocks were of similar precariousness 2.5 ka, 5 ka, and 10 ka ago. These specific targets will provide important constraints on time since exceedance for the CyberShake models. We developed our sampling strategy to address subsurface inheritance, exhumation rate and timing, and post- exhumation spalling and chemical erosion. PBRs were selected to meet a variety of considerations. These rocks constrain ground motions from large earthquakes on the San Jacinto and Elsinore faults, in Southern California. Inherited concentrations lead to an age estimate that is too old; we are investigating inherited concentrations though sampling a rock quarry near Perris CA, with shielded samples at greater than 15 m depth. We also have partially shielded samples from the interior of rocks toppled to measure their stability, and through vandalism. To determine exhumation age and rate, our sampling strategy is to collect 5-6 samples per PBR: 1 on top, 3

  20. Methods for estimating the content of transuranium and other difficult to measure nuclides in produced rad waste from BWRs

    During operation of nuclear power reactors a large number of radionuclides are produced. Some of them are difficult to measure. These are alpha or beta emitting radionuclides with weak or no gamma transition(s). A number of them, for instance some of the transuranium isotopes, may have significant radiological impact. It is of interest to be able to estimate the activity levels of these nuclides in the reactor systems. It is also of significant importance to estimate their content in produced waste packages and their radiological impact. In the report sources and source strengths for uranium and transuranium isotopes as well as for selected activated corrosion products are provided. Models for estimating the activity levels of these nuclides in the reactor systems and in different waste types are proposed. It is shown that the only significant source of uranium and transuranium nuclides is dispersion of fuel during operation of a reactor with defected and degrading fuel. The total amount of uranium on the core surfaces (tramp uranium), for a reactor in which no severe fuel failures have occurred, is about 0.5 g U, containing 2 % fissile material. During operation with defected fuel, up to 400 g U has been dispersed in the reactor water and distributed in the primary system during one single fuel cycle. Models for estimations of the amount of tramp uranium on the core surfaces during operation with no defected rods and the accumulation of uranium during operation with degrading fuel are provided. These models form the basis for consequence analyses of fuel failures and estimations of the amount of alpha emitting nuclides in different types of waste. 19 refs

  1. Very Big Accelerators as Energy Producers

    Wilson, R R

    2010-01-01

    One consequence of the application of superconductivity to accelerator construction is that the power consumption of accelerators will become much smaller. This raises the old possibility of using high energy protons to make neutrons which are then absorbed by fertile uranium or thorium to make a fissionable material like plutonium that can be burned in a nuclear reactor. The Energy Doubler/Saver being constructed at Fermilab is to be a superconducting accelerator that will produce 1000 GeV protons. The expected intensity of about $10^{12}$ protons per second corresponds to a beam power of about 0.2 MW. The total power requirements of the Doubler will be about 20 MW of which the injector complex will use approximately 13 MW, and the refrigeration of the superconducting magnets will use about 7 MW. Thus the beam power as projected is only a few orders of magnitude less than the accelerator power. But each 1000 GeV proton will produce about 60,000 neutrons in each nuclear cascade shower that is releaseq in a bl...

  2. ActiWiz – optimizing your nuclide inventory at proton accelerators with a computer code

    Vincke, Helmut

    2014-01-01

    When operating an accelerator one always faces unwanted, but inevitable beam losses. These result in activation of adjacent material, which in turn has an obvious impact on safety and handling constraints. One of the key parameters responsible for activation is the chemical composition of the material which often can be optimized in that respect. In order to facilitate this task also for non-expert users the ActiWiz software has been developed at CERN. Based on a large amount of generic FLUKA Monte Carlo simulations the software applies a specifically developed risk assessment model to provide support to decision makers especially during the design phase as well as common operational work in the domain of radiation protection.

  3. Analysis of primordial nuclides in high purity copper with Accelerator Mass Spectrometry

    The sensitivity of experiments in rare event physics like neutrino or direct dark matter detection crucially depends on the background level. Therefore, all material surrounding the detectors requires low contamination of radionuclides to not create additional background. A significant contribution originates from the primordial actinides thorium and uranium and the progenies of their decay chains. At the Maier Leibnitz Laboratorium in Munich the applicability of ultra-sensitive Accelerator Mass Spectrometry (AMS) for the direct detection of thorium and uranium impurities in a copper matrix was tested for the first time. For this special purpose, Th and U were extracted from the ion source as a copper compound. Two different samples of copper and one sample of a copper alloy were investigated. The lowest concentrations achieved with these first AMS measurements were (1.4±0.6).10-11 g/g for thorium and (7±4).10-14 g/g for uranium which correspond to (56±16) μBq/kg and (0.9±0.5) μBq/kg, respectively. The particular requirements on the AMS technique and the developed measurement procedure are presented, followed by a discussion of the results of the first measurements.

  4. Ultrasensitive detection method for primordial nuclides in copper with Accelerator Mass Spectrometry

    Famulok, N.; Faestermann, T.; Fimiani, L.; Gómez-Guzmán, J. M.; Hain, K.; Korschinek, G.; Ludwig, P.; Schönert, S.

    2015-10-01

    The sensitivity of rare event physics experiments like neutrino or direct dark matter detection crucially depends on the background level. A significant background contribution originates from the primordial actinides thorium (Th) and uranium (U) and the progenies of their decay chains. The applicability of ultra-sensitive Accelerator Mass Spectrometry (AMS) for the direct detection of Th and U impurities in three copper samples is evaluated. Although AMS has been proven to reach outstanding sensitivities for long-lived isotopes, this technique has only very rarely been used to detect ultra low concentrations of primordial actinides. Here it is utilized for the first time to detect primordial Th and U in ultra pure copper serving as shielding material in low level detectors. The lowest concentrations achieved were (1.5 ± 0.6) ·10-11 g/g for Th and (8 ± 4) ·10-14 g/g for U which corresponds to (59 ± 24) and (1.0 ± 0.5) μBq/kg, respectively.

  5. Target spot localization at neutron producing accelerators

    In the application of neutron producing accelerators it is required to know the actual position and the homogeneity of distribution of the emitted neutrons. Solid state nuclear track detectors offer a good possibility to get precise information on these without any disturbing influence on them. LR 115 2 type cellulose nitrate Kodak-Pathe Foils were irradiated with fast neutrons. When track density is higher than about 104 tracks cm-2 the damaged area can be observed with the naked eye, too. To get quantitative information the track densities were counted with manual technique. (author)

  6. Blood irradiation with accelerator produced electron beams

    Blood and blood products are irradiated with gamma rays to reduce the risk of graft versus host disease (GVHD). A simple technique using electron beams produced by a medical linear accelerator has been studied to evaluate irradiation of blood and blood products. Variations in applied doses for a single field 20 MeV electron beam are measured in a phantom study. Doses have been verified with ionization chambers and commercial diode detectors. Results show that the blood product volume can be given a relatively homogeneous dose to within 6% using 20 MeV electrons without the need to rotate the blood bags or the beam entry point. The irradiation process takes approximately 6.5 minutes for 30 Gy applied dose to complete as opposed to 12 minutes for a dual field x-ray field irradiation at our centre. Electron beams can be used to satisfactorily irradiate blood and blood products in a minimal amount of time. (author)

  7. Dose coefficients for radionuclides produced in high energy proton accelerator facilities. Coefficients for radionuclides not listed in ICRP publications

    Effective dose coefficients, the committed effective dose per unit intake, by inhalation and ingestion have been calculated for 304 nuclides, including (1) 230 nuclides with half-lives ≥ 10 min and their daughters that are not listed in ICRP Publications and (2) 74 nuclides with half-lives < 10 min that are produced in a spallation target. Effective dose coefficients for inhalation of soluble or reactive gases have been calculated for 21 nuclides, and effective dose rates for inert gases have been calculated for 9 nuclides. Dose calculation was carried out using a general-purpose nuclear decay database DECDC developed at JAERI and a decay data library newly compiled from the ENSDF for the nuclides abundantly produced in a spallation target. The dose coefficients were calculated with the computer code DOCAP based on the respiratory tract model and biokinetic model of ICRP. The effective dose rates were calculated by considering both external irradiation from the surrounding cloud and irradiation of the lungs from the gas within them. The calculated results are presented as tables, which are the same forms as those in ICRP Publs. 68 and 72. The complete listings of the dose coefficients are arranged on a CD-ROM, DoseCD, as indexed tables for inhalation of 10 particle sizes, ingestion and injection into blood for workers and members of the public. The dose coefficients calculated in the present study as well as those published in a series of ICRP Publications will be sufficient to calculate internal doses for a variety of radionuclides produced in high energy proton accelerator facilities. (author)

  8. The present scope of the field of terrestrial cosmogenic nuclides

    The discovery of natural radiocarbon produced by cosmic rays in the earth's atmosphere by Libby in the late forties was followed by the discovery of terrestrial cosmogenic nuclide 3H in 1951. In the next few years several terrestrial cosmogenic radionuclides were detected. The cosmogenic nuclides found a variety of new applications during 1960-1970 in meteorology, hydrology, glaciology and oceanography. The three long-lived cosmogenic nuclides produced in the atmosphere with half-lives>100 yr, 32Si, 14C, 26Al and 10Be continued to provide invaluable data in the field of oceanography, using the methods developed in the sixties. However, in the late seventies the developement of the accelerator mass spectrometry (AMS) technique made it possible to measure several long-lived radionuclides with 3-6 orders of magnitude higher sensitivity. This led to an explosion in the eighties in the scope of applications of cosmogenic nuclides in both terrestrial and extraterrestrial samples. This article attempts to convey the sense of the present excitement of cosmogenic nuclides as tools in geosciences, while highlighting the modern development with perspectives of the forties and fifties when the terrestrial cosmogenic nuclides 14C, 3H, 10Be and others were discovered. (author). 79 refs., 2 figs., 4 ta bs

  9. Macroscopic cross sections of neutron radiation capture by Pb-208, U-238 and Tc-99 nuclides in the accelerator driven subcritical core cooled with molten Pb-208 - 286

    In the paper macroscopic cross sections for several isotopes: 208Pb, 238U, 99Tc and natural mix of lead isotopes, natPb, averaged over neutron spectra of the accelerator driven subcritical core cooled with natPb or 208Pb are given. It is shown that macro cross sections for a coolant from 208Pb are by 6.2 times smaller than those for the coolant consisted from natPb. The economy of neutrons in the core cooled with molten 208Pb can be used for reducing initial fuel load, increasing plutonium breeding and enhancing transmutation of such long lived fission products as 99Tc. The values of macro cross sections calculated for 238U and 99Tc, equal to 0.6 and 0.8 barns, respectively, are comparable with the values of the same nuclide macro cross sections for neutron spectrum of the fast reactor core cooled with sodium. Good neutron and physical features of molten 208Pb permit to assume it as perspective coolant for fast reactors and accelerator driven systems. (authors)

  10. Nuclides Economy

    Traditionally the subject of discussion about the nuclear technology development is focused on the conditions that facilitate the nuclear power deployment. The main objective of this work is seeking of methodological basis for analysis of the coupling consequences of nuclear development. Nuclide economy is the term, which defines a new kind of society relations, dependent on nuclear technology development. It is rather closed to the setting of problems then to the solving of them. Last year Dr. Jonathan Tennenbaum published in Executive Intelligence Review Vol. 33 no 40 the article entitled as 'The Isotope Economy' where main interconnections for nuclear energy technologies and their infrastructure had been explained on the popular level. There he has given several answers and, therefore, just here we will try to expand this concept. We were interested by this publication because of similarity of our vision of resource base of technologies development. The main paradigm of 'Isotope economy' was expresses by Lyndon H. LaRouche: 'Instead of viewing the relevant resources of the planet as if they were a fixed totality, we must now assume responsibility of man's creating the new resources which will be more than adequate to sustain a growing world population at a constantly improved standard of physical per-capita output, and personal consumption'. We also consider the needed resources as a dynamic category. Nuclide economy and nuclide logistics both are needed for identifying of the future development of nuclear power as far we follow the holistic analysis approach 'from cave to grave'. Thus here we try to reasoning of decision making procedures and factors required for it in frame of innovative proposals development and deployment. The nuclear power development is needed in humanitarian scientific support with maximally deep consideration of all inter-disciplinary aspects of the nuclear power and nuclear technologies implementation. The main objectives for such

  11. Dose coefficients for radionuclides produced in high energy proton accelerator facilities. Coefficients for radionuclides not listed in ICRP publications

    Kawai, K; Noguchi, H

    2002-01-01

    Effective dose coefficients, the committed effective dose per unit intake, by inhalation and ingestion have been calculated for 304 nuclides, including (1) 230 nuclides with half-lives >= 10 min and their daughters that are not listed in ICRP Publications and (2) 74 nuclides with half-lives < 10 min that are produced in a spallation target. Effective dose coefficients for inhalation of soluble or reactive gases have been calculated for 21 nuclides, and effective dose rates for inert gases have been calculated for 9 nuclides. Dose calculation was carried out using a general-purpose nuclear decay database DECDC developed at JAERI and a decay data library newly compiled from the ENSDF for the nuclides abundantly produced in a spallation target. The dose coefficients were calculated with the computer code DOCAP based on the respiratory tract model and biokinetic model of ICRP. The effective dose rates were calculated by considering both external irradiation from the surrounding cloud and irradiation of the lun...

  12. Measurement of fission product nuclide 126Sn with accelerator mass spectrometry based on SnF2 target

    A new analytical method, using SnF2 target and extracting SnF3- molecular negative ions, was developed at CIAE HI-13 Accelerator Mass Spectrometry System for measurement of 126Sn. The development of the 126Sn calibration standard for AMS measurement and the preparation flow of target materials SnF2 were described in this paper. The results indicate that the extraction ion form SnF3- can depress the interference of 126Te as much as 2-3 order of magnitude. A perfect linearity (R2=0.999) between measured and nominal 126Sn/Sn atom number ratios was obtained by using three standard samples with 126Sn/Sn atom number ratios of 1.033 ×10-8, 4.54 ×10-9, and 6.43 ×10-10. A sensitivity of (1.92±1.13) ×10-10 (126Sn/Sn) was reached by measuring a blank sample. (authors)

  13. Laser-Produced and Accelerated High Energy Protons

    Cowan, Thomas

    2005-04-01

    Ultra-low emittance, multi-MeV proton beams have recently been produced by the interaction of high-intensity short-pulse lasers with thin metallic foils [1]. The acceleration process proceeds in two steps. First the laser ponderomotively accelerates huge, MA currents of ˜MeV electrons which propagate through the foil and form a dense relativistic electron sheath on the non-irradiated rear surface. This sheath produces an electrostatic field >10^12 V/m that ionizes the surface atoms almost instantaneously, forming a ˜1 nm thick ion layer which, together with the electron sheath, resembles a virtual cathode. The ions are accelerated initially normal to the foil surface, followed by a diverging plasma expansion phase driven by the electron plasma pressure. By structuring the rear surface of the foil, we have succeeded to produce modulations in the transverse phase space of the ions, which resemble fiducial ``beamlets'' within the envelope of the expanding plasma. This allows one to image the initial accelerating sheath, and map the plasma expansion of the beam envelope, to fully reconstruct the transverse phase space. We find that for protons of 10 MeV, the normalized transverse rms emittance is less than 0.004 π mm.mrad [1], i.e. 100-fold better than typical RF accelerators and at substantially higher ion currents exceeding 10 kA. Recent results will be reported on stripping the electrons while maintaining the low emittance from experiments at the LULI 100 TW laser, and theoretical estimates of the lowest emittance which can be expected based on ion heating mechanisms during the initial sheath formation and ion acceleration processes, will be presented. [1] T.E. Cowan, J. Fuchs, H. Ruhl et al., Phys. Rev. Lett. 92, 204801 (2004).

  14. Neutronic fields produced by a lineal accelerator for radiotherapy

    Measurements and Monte Carlo calculations has been utilized to determine the dosimetric features as well as the neutron spectra of photoneutrons produced around an 18 MV linear accelerator for radiotherapy. Measurements were carried out with bare and Cd covered thermoluminescent dosimeters, TLD600 and TLD700, as well as inside a paraffine moderator. TLD pairs were also utilized as thermal neutrons inside a Bonner sphere spectrometer (au)

  15. Cosmogenic nuclides in meteorites

    After successful installation of the Dresden Accelerator Mass Spectrometry (DREAMS) facility, determinations of the lighter radionuclides 10Be, 26Al, and 41Ca are now easily attainable in Germany. Accompanied by data for the heavier radionuclides (i.e. 53Mn and 60Fe) that can be measured at the 14 MV tandem at Munich and stable nuclides such as 21,22Ne and 38Ar from noble gas mass spectrometry at MPI Mainz, complete and unique exposure histories of extraterrestrial material can be reconstructed. For example, recent analyses of the 100th Martian meteorite Ksar Ghilane 002 and four samples from the nickel-rich ataxite Gebel Kamil show interesting features revealing amazing stories.

  16. Naturally occurring and accelerator-produced radioactive materials: 1987 review

    From time to time, the issue as to whether the US Nuclear Regulatory Commission (NRC) should seek legislative authority to regulate naturally occurring and accelerator-produced radioactive materials (NARM) is raised. Because NARM exists in the environment, in homes, in workplaces, in medical institutions, and in consumer products, the issue of Federal controls over NARM is very old and very complex. This report presents a review of NARM sources and uses as well as incidents and problems associated with those materials. A review of previous congressional and Federal agency actions on radiation protection matters, in general, and on NARM, in particular, is provided to develop an understanding of existing Federal regulatory activity in ionizing radiation and in control of NARM. In addition, State controls over NARM are reviewed. Eight questions are examined in terms of whether the NRC should seek legislative authority to regulate NARM. The assessment of these questions serves as the basis for developing and evaluating five options. The evaluation of those options leads to two recommendations

  17. Achievement of accelerator parameters needed for energy producing and waste transmuting ADS

    An attractive approach to the achievement of the accelerator parameters needed for systems producing energy and burning wastes, based on the use of circular machines, which are more compact compared with the linear accelerators, is briefly presented

  18. Producing Massive Neutral Intermediate Vector Bosons with Existing Accelerators

    Rubbia, C; Cline, D

    1978-01-01

    We outline a scheme of searching for the massive weak boson (M = 50 – 200 GeV/c2). An antiproton source is added either to the Fermilab or the CERN SPS machines to transform a conventional 400 GeV accelerator into a pp̄ colliding beam facility with 800 GeV in the center of mass (Eeq = 320,000 GeV). Reliable estimates of production cross sections along with a high luminosity make the scheme feasible.

  19. Pinched Material Einstein Space-Time Produces Accelerated Cosmic Expansion

    M. S. El Naschie

    2014-01-01

    An instructive analogy between the deformation of a pinched elastic cylindrical shell and the anti-gravity behind accelerated cosmic expansion is established. Subsequently the entire model is interpreted in terms of a hyperbolic fractal Rindler space-time leading to the same robust results regarding real energy and dark energy being 4.5% and 95.5% respectively in full agreement with all recent cosmological measurements.

  20. The MacNuclide nuclear data environment

    Advance in technology have produced intriguing tools that can be applied to problems in nuclear science. Information management in nuclear science is an example of how technology is not quickly exploited. The U.S. Department of Energy supports an extensive program to evaluate published nuclear properties and store them in an electronic data base. Much of the evaluation effort has focused on producing the journal Nuclear Data Sheets and the publication Table of Isotopes. Although the electronic data base can itself be a valuable source of information, the software used to access is was designed using decades-old technologies. The authors of this paper have developed a novel data-base management system for nuclear properties. The application is known as MacNuclide. It is a nuclear data-base environment that uses the highly interactive and intuitive windowing environmentsof desk-top computers. The environment is designed around that image of the chart of nuclides. Questions are posed to the data base by placing constraints on properties and defining collections of nuclides to be used in data-base seraches. Results are displayed either as a simple list of nuclides that meet the imposed constraints or as a color chart of nuclides

  1. Post acceleration of a pseudospark-produced high-brightness electron beam

    Preliminary results are presented of post-acceleration experiment of a pseudospark-produced high-brightness electron beam. The electron beam that is propagating in a low pressure gas is accelerated by a simple induction linac system. Time-resolved energy spectrum is constructed for the electron beam. The resultant spectrum reveals that the instantaneous beam energy is approximately equal to the sum of the cathode voltage and the induction-linac accelerating voltage

  2. WWW chart of the nuclides

    WWW chart of the nuclides was established on the basis of the latest evaluations of nuclear structure and decay data. By viewing WWW chart of the nuclides, one can retrieve the fundamental data of nuclide such as atomic mass, abundance, spin and parity; the decay mode, branching ratio, half-life and Q-value of radioactive nuclide, energy and intensity of strong γ-ray, etc. The URL (Uniform Resource Locator) of WWW chart of the nuclides is: http://myhome.py.gd.cn/chart/index,asp

  3. Numerical simulation of in situ production of cosmogenic nuclides: Effects of irradiation geometry

    A variety of geomorphic events and processes can be studied with the cosmogenic nuclides accumulated in the exposed materials. Reliable interpretation of the measured in situ produced cosmogenic nuclides requires a good understanding of the involved nuclear processes. The production rates of nuclides depend on many parameters. In this paper, calculations for the production rates of in situ produced cosmogenic nuclides in rocks of various sizes on sloped surfaces are reported and discussed

  4. Consideration with regard to feasible objective nuclide in next experiment

    The present status of investigation on the superheavy nuclei are analyzed. After 259Db synthesized, the next objective nuclide is determined to be 265Bh, a new isotope of Z=107 element, according to our existing available equipment and conditions. The test result of the MG rotating wheel collection and detection system is described. The α-decay spectra of mother-daughter of the product 252No from 24Mg + 232Th reaction are observed and measured successfully in this test experiment. It is regarded as a preliminary and probatory experiment for synthesis of 265Bh in next stage. The predicted decay properties for next objective nuclide are also given in this paper. And the projectile-target combination and reaction channel to produce this objective nuclide are selected. The production cross section for the objective nuclide is estimated roughly. The observable yields and the feasibility for producing this objective nuclide are calculated and discussed

  5. Radioactivity Measurement of Short Life Nuclide 89Rb

    2008-01-01

    <正>The radioactivity of short life nuclide 89Rb produced by fast radiochemical separation was measured by the digital coincidence counting (DCC) system. In this experiment, there were a large quantity of impurities

  6. Unconventional Nuclides for Radiopharmaceuticals

    Holland, Jason P.; Williamson, Matthew J.; Lewis, Jason S.

    2016-01-01

    Rapid and widespread growth in the use of nuclear medicine for both diagnosis and therapy of disease has been the driving force behind burgeoning research interests in the design of novel radiopharmaceuticals. Until recently, the majority of clinical and basic science research has focused on the development of 11C-, 13N-, 15O-, and 18F-radiopharmaceuticals for use with positron emission tomography (PET) and 99mTc-labeled agents for use with single-photon emission computed tomography (SPECT). With the increased availability of small, low-energy cyclotrons and improvements in both cyclotron targetry and purification chemistries, the use of “nonstandard” radionuclides is becoming more prevalent. This brief review describes the physical characteristics of 60 radionuclides, including β+, β−, γ-ray, and α-particle emitters, which have the potential for use in the design and synthesis of the next generation of diagnostic and/or radiotherapeutic drugs. As the decay processes of many of the radionuclides described herein involve emission of high-energy γ-rays, relevant shielding and radiation safety issues are also considered. In particular, the properties and safety considerations associated with the increasingly prevalent PET nuclides 64Cu, 68Ga, 86Y, 89Zr, and 124I are discussed. PMID:20128994

  7. Bremsstrahlung dose of therapeutic beta nuclides in bone and muscle

    Manjunatha, H. C.

    2013-01-01

    In the nuclear medicine, beta nuclides are released during the treatment. This beta interacts with bone and muscle and produces external Bremsstrahlung (EB) radiation. Present work formulated a new method to evaluate the EB spectrum and hence the Bremsstrahlung dose of therapeutic beta nuclides (Lu-177, Sr-90, Sm-153, I-153, Cs-137, Au-201, Dy-165, Mo-99, Sr-89, Fe-59, P-32, Ho-166, Sr-92, Re-188, Y-90, Pr-147, Co-60, K-42) in bone and muscle. The Bremsstrahlung yields of these beta nuclides ...

  8. Uptake of nuclides by plants

    Greger, Maria [Stockholm Univ. (Sweden). Dept. of Botany

    2004-04-01

    This review on plant uptake of elements has been prepared to demonstrate how plants take up different elements. The work discusses the nutrient elements, as well as the general uptake and translocation in plants, both via roots and by foliar absorption. Knowledge of the uptake by the various elements within the periodic system is then reviewed. The work also discusses transfer factors (TF) as well as difficulties using TF to understand the uptake by plants. The review also focuses on species differences. Knowledge necessary to understand and calculate plant influence on radionuclide recirculation in the environment is discussed, in which the plant uptake of a specific nuclide and the fate of that nuclide in the plant must be understood. Plants themselves determine the uptake, the soil/sediment determines the availability of the nuclides and the nuclides themselves can interact with each other, which also influences the uptake. Consequently, it is not possible to predict the nuclide uptake in plants by only analysing the nuclide concentration of the soil/substrate.

  9. Library correlation nuclide identification algorithm

    A novel nuclide identification algorithm, Library Correlation Nuclide Identification (LibCorNID), is proposed. In addition to the spectrum, LibCorNID requires the standard energy, peak shape and peak efficiency calibrations. Input parameters include tolerances for some expected variations in the calibrations, a minimum relative nuclide peak area threshold, and a correlation threshold. Initially, the measured peak spectrum is obtained as the residual after baseline estimation via peak erosion, removing the continuum. Library nuclides are filtered by examining the possible nuclide peak areas in terms of the measured peak spectrum and applying the specified relative area threshold. Remaining candidates are used to create a set of theoretical peak spectra based on the calibrations and library entries. These candidate spectra are then simultaneously fit to the measured peak spectrum while also optimizing the calibrations within the bounds of the specified tolerances. Each candidate with optimized area still exceeding the area threshold undergoes a correlation test. The normalized Pearson's correlation value is calculated as a comparison of the optimized nuclide peak spectrum to the measured peak spectrum with the other optimized peak spectra subtracted. Those candidates with correlation values that exceed the specified threshold are identified and their optimized activities are output. An evaluation of LibCorNID was conducted to verify identification performance in terms of detection probability and false alarm rate. LibCorNID has been shown to perform well compared to standard peak-based analyses

  10. Uptake of nuclides by plants

    This review on plant uptake of elements has been prepared to demonstrate how plants take up different elements. The work discusses the nutrient elements, as well as the general uptake and translocation in plants, both via roots and by foliar absorption. Knowledge of the uptake by the various elements within the periodic system is then reviewed. The work also discusses transfer factors (TF) as well as difficulties using TF to understand the uptake by plants. The review also focuses on species differences. Knowledge necessary to understand and calculate plant influence on radionuclide recirculation in the environment is discussed, in which the plant uptake of a specific nuclide and the fate of that nuclide in the plant must be understood. Plants themselves determine the uptake, the soil/sediment determines the availability of the nuclides and the nuclides themselves can interact with each other, which also influences the uptake. Consequently, it is not possible to predict the nuclide uptake in plants by only analysing the nuclide concentration of the soil/substrate

  11. Application of on-line HPLC-ICP-MS for the determination of the nuclide abundances of lanthanides produced via spallation reactions in an irradiated tantalum target of a spallation neutron source

    Kerl, W.; Becker, J.S.; Dietze, H.J. [Forschungszentrum Juelich GmbH (Germany). Zentralabteilung fuer Chemische Analysen; Dannecker, W. [Institut fuer Anorganische und Angewandte Chemie der Universitaet Hamburg, D-20146 Hamburg (Germany)

    1998-11-01

    An analytical procedure has been developed for the determination of spallation nuclides in an irradiated tantalum target using HPLC coupled on-line to ICP-MS after dissolution and separation of the tantalum matrix. Pieces of tantalum were taken from different locations of the irradiated tantalum target which had been used as the target material in a spallation neutron source. Tantalum was dissolved in a HNO{sub 3}/HF mixture and the tantalum matrix was separated by liquid-liquid extraction so that only the spallation nuclides were left in the sample solutions. The major fraction of the spallation nuclides in the tantalum target are lanthanide metals in the {mu}g g{sup -1} concentration range determined in the present study. Additional reaction products are formed by the irradiation of trace impurities in the original tantalum target. The nuclide abundances of the lanthanide metals measured in the tantalum target differ significantly from the natural isotopic composition so that a lot of isobaric interferences of long-lived radionuclides and stable isotopes in the mass spectrum are to be expected. Therefore, all the lanthanide metals had to be separated chemically prior to their mass spectrometric determination. The separation of all rare earth elements was performed by ion chromatography on-line to ICP-MS. The nuclide abundances of each lanthanide were determined using a sensitive double-focusing sector field inductively coupled plasma mass spectrometer. The nuclide abundances of the lanthanides in the irradiated tantalum target calculated theoretically and the experimental results obtained by on-line HPLC-ICP-MS proved to be in good agreement. (orig.) With 4 figs., 3 tabs., 11 refs.

  12. Application of on-line HPLC-ICP-MS for the determination of the nuclide abundances of lanthanides produced via spallation reactions in an irradiated tantalum target of a spallation neutron source

    An analytical procedure has been developed for the determination of spallation nuclides in an irradiated tantalum target using HPLC coupled on-line to ICP-MS after dissolution and separation of the tantalum matrix. Pieces of tantalum were taken from different locations of the irradiated tantalum target which had been used as the target material in a spallation neutron source. Tantalum was dissolved in a HNO3/HF mixture and the tantalum matrix was separated by liquid-liquid extraction so that only the spallation nuclides were left in the sample solutions. The major fraction of the spallation nuclides in the tantalum target are lanthanide metals in the μg g-1 concentration range determined in the present study. Additional reaction products are formed by the irradiation of trace impurities in the original tantalum target. The nuclide abundances of the lanthanide metals measured in the tantalum target differ significantly from the natural isotopic composition so that a lot of isobaric interferences of long-lived radionuclides and stable isotopes in the mass spectrum are to be expected. Therefore, all the lanthanide metals had to be separated chemically prior to their mass spectrometric determination. The separation of all rare earth elements was performed by ion chromatography on-line to ICP-MS. The nuclide abundances of each lanthanide were determined using a sensitive double-focusing sector field inductively coupled plasma mass spectrometer. The nuclide abundances of the lanthanides in the irradiated tantalum target calculated theoretically and the experimental results obtained by on-line HPLC-ICP-MS proved to be in good agreement. (orig.)

  13. Dosimetry and fast neutron energies characterization of photoneutrons produced in some medical linear accelerators

    Khaled, N. E.; Attalla, E. M.; Ammar, H.; Khalil, W.

    2011-12-01

    This work focusses on the estimation of induced photoneutrons energy, fluence, and strength using nuclear track detector (NTD) (CR-39). Photoneutron energy was estimated for three different linear accelerators, LINACs as an example for the commonly used accelerators. For high-energy linear accelerators, neutrons are produced as a consequence of photonuclear reactions in the target nuclei, accelerator head, field-flattening filters and beam collimators, and other irradiated objects. NTD (CR-39) is used to evaluate energy and fluence of the fast neutron. Track length is used to estimate fast photoneutrons energy for linear accelerators (Elekta 10 MV, Elekta 15 MV, and Varian 15 MV). Results show that the estimated neutron energies for the three chosen examples of LINACs reveals neutron energies in the range of 1-2 MeV for 10 and 15 MV X-ray beams. The fluence of neutrons at the isocenter (Φtotal) is found to be (4×106 n cm2 Gy-1) for Elekta machine 10 MV. The neutron source strengths Q are calculated. It was found to be 0.2×1012 n Gy-1 X-ray at the isocenter. This work represents simple, low cost, and accurate methods of measuring fast neutrons dose and energies.

  14. 2014 update of the discoveries of nuclides

    The 2014 update of the discovery of nuclide project is presented. Only six new nuclides were observed for the first time in 2014 while the assignments of 17 other nuclides were revised. In addition, for another 14 nuclides the laboratories where they were discovered were reassigned. (author)

  15. How to Produce a Reactor Neutron Spectrum Using a Proton Accelerator

    Burns, K.; Wootan, D.; Gates, R.; Schmitt, B.; Asner, D. M.

    A method for reproducing the neutron energy spectrum present in the core of an operating nuclear reactor using an engineered target in an accelerator proton beam is proposed. The protons interact with a target to create neutrons through various (p,n) type reactions. Spectral tailoring of the emitted neutrons can be used to modify the energy of the generated neutron spectrum to represent various reactor spectra. Through the use of moderators and reflectors, the neutron spectrum can be modified to reproduce many different spectra of interest including spectra in small thermal test reactors, large pressurized water reactors, and fast reactors. The particular application of this methodology is the design of an experimental approach for using an accelerator to measure the betas produced during fission to be used to reduce uncertainties in the interpretation of reactor antineutrino measurements. This approach involves using a proton accelerator to produce a neutron field representative of a power reactor, and using this neutron field to irradiate fission foils of the primary isotopes contributing to fission in the reactor, creating unstable, neutron rich fission products that subsequently beta decay and emit electron antineutrinos. A major advantage of an accelerator neutron source over a neutron beam from a thermal reactor is that the fast neutrons can be slowed down or tailored to approximate various power reactor spectra. An accelerator based neutron source that can be tailored to match various reactor neutron spectra provides an advantage for control in studying how changes in the neutron spectra affect parameters such as the resulting fission product beta spectrum.

  16. How to produce a reactor neutron spectrum using a proton accelerator

    Burns, Kimberly A.; Wootan, David W.; Gates, Robert O.; Schmitt, Bruce E.; Asner, David M.

    2015-01-01

    A method for reproducing the neutron energy spectrum present in the core of an operating nuclear reactor using an engineered target in an accelerator proton beam is proposed. The protons interact with a target to create neutrons through various (p,n) type reactions. Spectral tailoring of the emitted neutrons can be used to modify the energy of the generated neutron spectrum to represent various reactor spectra. Through the use of moderators and reflectors, the neutron spectrum can be modified to reproduce many different spectra of interest including spectra in small thermal test reactors, large pressurized water reactors, and fast reactors. The particular application of this methodology is the design of an experimental approach for using an accelerator to measure the betas produced during fission to be used to reduce uncertainties in the interpretation of reactor antineutrino measurements. This approach involves using a proton accelerator to produce a neutron field representative of a power reactor, and using this neutron field to irradiate fission foils of the primary isotopes contributing to fission in the reactor, creating unstable, neutron rich fission products that subsequently beta decay and emit electron antineutrinos. A major advantage of an accelerator neutron source over a neutron beam from a thermal reactor is that the fast neutrons can be slowed down or tailored to approximate various power reactor spectra. An accelerator based neutron source that can be tailored to match various reactor neutron spectra provides an advantage for control in studying how changes in the neutron spectra affect parameters such as the resulting fission product beta spectrum.

  17. Implementation of a mass spectrometer operating in the external beam of a proton accelerator. Application to the study of short-lived isotopes produced by uranium fission

    Implementation and use of a mass spectrometer operating directly in the external beam of a proton accelerator has proven to be a very fruitful way to study short-lived nuclides in both areas covered: measuring production cross sections and nuclear spectroscopy. The results obtained in this work are only a first step and can be developed in different directions in which the study was discussed and an extension to elements other than alkali may be considered. (author)

  18. Processing and evaluation of linear accelerator-produced 99Mo/99mTc in Canada

    We are developing electron linear accelerator 100Mo(γ,n)99Mo technology as a replacement to nuclear reactor 235U(n,f)99Mo production. We report irradiation of natural molybdenum disks (25 MeV, 10 kW) and 100Mo-enriched disks (35 MeV, 2 kW), their dissolution and the extraction of 99mTc-pertechnetate. Up to 6.2 GBq 99Mo was produced, solvent extraction was performed at >90 % yields of 99mTc, and quality control showed that a product with high radionuclidic and radiochemical purity could be obtained. Irradiated natural molybdenum products showed more impurities (91mNb, 92mNb, 95mNb and 95Nb) than enriched target material. Linear accelerator technology is feasible for production of quality 99Mo/99mTc, particularly when paired with 100Mo-enriched targets. (author)

  19. Nuclide content in reactor waste

    Certain corrosion and fission products of importance in reactor waste management cannot be measured by gammaspectrometric techniques. In this study, a method is suggested by which the occurence of such nuclides can be quantitatively related to suitable gamma-emitters of similar origin. The method is tested by statistical analysis on the waste data recorded from two Swedish nuclear power plants. As this method is not applicable for Carbon-14, this nuclide was measured directly in spent ion exchange resins from three Finnish and Swedish power plants. (author)

  20. The nuclide inventory in SFR-1

    This report is an account for a project carried out on behalf of the Swedish Radiation Protection Authority (SSI): 'Nuclide inventory in SFR-1' (The Swedish underground disposal facility for low and intermediate level reactor waste). The project comprises the following five sub-projects: 1) Measuring methods for nuclides, difficult to measure, 2) The nuclide inventory in SFR-1, 3) Proposal for nuclide library for SFR-1 and ground disposal, 4) Nuclide library for exemption, and 5) Characterising of the nuclide inventory and documentation for SFL waste. In all five sub-projects long-lived activity, including Cl-36, has been considered

  1. Predicting the production rates of cosmogenic nuclides in extraterrestrial matter

    The production rates of nuclides made by the galactic and solar cosmic rays are important in the interpretations of measurements made with lunar samples, meteorites, and cosmic spherules. Production rates of cosmogenic nuclides have been predicted by a variety of methods that are reviewed in this paper, ranging from systematic studies of one or a group of meteorites to purely theoretical calculations. Production rates can vary with the chemical composition and the preatmospheric depth of the sample and with the size and shape of the object. While the production systematics for cosmogenic nuclides are fairly well known, our ability to predict their production rates can be improved, with a corresponding increase in the scientific return. Additional detailed studies of cosmogenic nuclides in extraterrestrial objects are needed, especially for fairly small and very large objects. Nuclides made in simulation experiments and cross sections for many major nuclear reactions should be measured. Such studies are especially needed for the long-lived radionuclides that have only recently become readily measurable by accelerator mass spectrometry. 34 refs., 5 figs

  2. Nuclides for radiotherapy: an overview

    With the emergence of new, biological vehicles of great organ specificity (e.g. steroid hormones, antibodies) the concept of systemic tumor therapy with the aid of radiotherapeutica has gained new momentum. In order to assess the options open for optimal adaptation of the radiation properties to the pharmacocinetics of a vehicle, a search was done to identify potentially useful therapeutic radionuclides. Main criteria for selection were half life, low gamma-yield and stable daughter nuclide. The resulting possibilities fall into 4 categories: 1) alpha-emitters (At-211); 2) beta/sup -/-emitters that can be prepared in a carrierfree fashion (P-32, S-35, As-77, Y-90, Ag-111, Pm-149, Tb-161, Lu-177), 3) beta/sup -/-emitters with carrier added (Pd-109, Pr-142, Gd-159, Er-169, Tm-172, Yb-175, Re-188, Ir-194, Pt-197) and 4) electron capture nuclides, emitting Auger-cascades (Cr-51, Ga-67, Ge-71, Br-77, Ru-97, Sb-119, I-123, Cs-129, Nd-140, Er-165, Ta-177, Hg-197, Tl-201). Among the 4th group some well known, diagnostically used nuclides are found. Their therapeutic use necessitates the precise localisation in or very near the genetic material of the cell to be killed; only there the destructive power of the very short range Auger-electrons can be used. For each of the selected nuclides a summary of decay data, possibilities of preparation and chemical reactivity for labelling of vehicles is given. (author)

  3. Penning trap mass measurements of nuclides along the astrophysical rp- and νp- process paths

    Clark, Jason

    2009-10-01

    X-ray bursters and supernovae are examples of explosive stellar phenomena in which nuclides are quickly produced in great quantities. Observed as x-ray bursts, thermonuclear runaways on the surface of neutron stars accreting material from its binary star companion create elements by a nucleosynthetic procoess which involves a series of rapid proton-capture reactions, termed the rp process. The timescale, nuclides produced, and energy released during the rp process are very sensitive to delays encountered at waiting-point nuclides, nuclides in which their slow β decay is more probable than net proton capture. A possible mechanism to bypass the waiting-point nuclides is through the νp process, in which (n,p) and (n,γ) reactions on the waiting-point nuclides, in addition to the proton-capture reactions, are possible. Supernovae are possible sites for the νp process as the proton-rich ejecta can absorb antineutrinos to produce the required free neutrons. It is this νp process which may resolve the long-standing discrepancy between the observed and predicted abundances of ^92Mo and ^94Mo. Proton-capture Q values of nuclides along the rp- and νp- process paths are required to accurately model the nucleosynthesis, especially at the waiting-point nuclides. In recent years, Penning traps have become the preferred tool to make precise mass measurements of stable and unstable nuclides. To make the best use of these devices in measuring the masses of radioactive nuclides, systems have been developed to quickly, cleanly, and efficiently transport the short-lived, weakly produced nuclides to the Penning traps. This talk will discuss the rp and νp nucleosynthetic processes and will highlight the precise Penning trap mass measurements of nuclides along these process paths.

  4. Regulation of naturally occurring and accelerator-produced radioactive materials. A Task Force review

    The use of accelerator-produced radioisotopes (NARM), particularly in medicine, is growing rapidly. One NARM radioisotope, 226Ra, is one of the most hazardous of radioactive materials, and 226Ra is used by about 1/5 of all radioactive material users. Also, there are about 85,000 medical treatments using 226Ra each year. All of the 25 Agreement States and 5 non-Agreement States have licensing programs covering NARM users. The Agreement States' programs for regulating NARM are comparable to their programs for regulating byproduct, source, and special nuclear materials under agreements with NRC. But there are 7 states who exercise no regulatory control over NARM users, and the remaining States have control programs which are variable in scope. There are no national, uniformly applied programs to regulate the design, fabrication and quality of sources and devices containing NARM or consumer products containing NARM which are distributed in interstate commerce. Naturally occurring radioactive material (except source material) associated with the nuclear fuel cycle is only partially subject to NRC regulation, i.e., when it is associated with source or special nuclear material being used under an active NRC license. The Task Force recommends that the NRC seek legislative authority to regulate naturally occurring and accelerator-produced radioactive materials for the reason that these materials present significant radiation exposure potential and present controls are fragmentary and non-uniform at both the State and Federal level

  5. Nuclides and isotopes. Twelfth edition

    This explanatory booklet was designed to be used with the Chart of the Nuclides. It contains a brief history of the atomic theory of matter: ancient speculations, periodic properties of elements (Mendeleev table), radioactivity, early models of atomic structure, the Bohr atom, quantum numbers, nature of isotopes, artificial radioactivity, and neutron fission. Information on the pre-Fermi (natural) nuclear reactor at Oklo and the search for superheavy elements is given. The booklet also discusses information presented on the Chart and its coding: stable nuclides, metastable states, data display and color, isotopic abundances, neutron cross sections, spins and parities, fission yields, half-life variability, radioisotope power and production data, radioactive decay chains, and elements without names. The Periodic Table of the Elements is appended. 3 figures, 3 tables

  6. Characterisation of mixed radiation field produced in medical linear accelerators using foil activation technique

    The photon spectrum produced in medical linear accelerators and used for tumour therapy was measured using foil activation techniques in this work. The machine employed is the linear medical accelerator SL-25, Philips, installed at the Walsgrave Hospital Radiotherapy Centre in Coventry, U.K. A number of foil sets, with different energy thresholds were irradiated at different points inside a 400 mm by 400 mm treatment field at a nominal dose rate of 400 MU (∼4 Gy/min), and photon energy of 25 MV at the machine's isocentre. The induced activity of each foil was measured using a NaI(Tl) detector and a PC-based multichannel analyzer. The spectrum of the photons was unfolded using the computer code LOUHI82. The relative changes in the spectrum across the treatment field, were also measured using foils placed at 2.5deg, 5deg, 10deg and 13deg on both sides of the central axis of the treatment field. In order to estimate the extra dose received by the patient due to the neutron component, the neutron flux distribution at different points across the treatment field was measured using gold foils. The results and implications are discussed. (author)

  7. Measurements of the highest acceleration gradient for ions produced with a long laser pulse

    Ultrafast plasma light ion streams have been produced using the 300 ps, kJ-class iodine laser, operating at PALS Centre in Prague. Ion detection was performed through standard ion collectors (IC) in time-of-flight configuration (TOF), shielded by thin metallic absorbers. This new diagnostics technique has been theoretically studied and experimentally tested in order to cut the long photopeak contribution and to analyze the ultrafast particle signal. Processing the obtained experimental IC-TOF data, including deconvolution processes of the TOF signals, UV/soft-x-ray photopeak absorption, and ion transmission calculations for different metallic filters, is shown. Mainly amorphous carbon (graphite) targets have been irradiated in order to limit the maximum number of ion charge states and to focus our study on demonstrating the validity of the proposed investigation technique. Maximum ion energy and acceleration gradient estimations as a function of the laser energy and focal spot diameter are reported.

  8. Fusion reactions initiated by laser-accelerated particle beams in a laser-produced plasma

    Labaune, C; Depierreux, S; Goyon, C; Loisel, G; Yahia, V; Rafelski, J

    2013-01-01

    The advent of high-intensity pulsed laser technology enables the generation of extreme states of matter under conditions that are far from thermal equilibrium. This in turn could enable different approaches to generating energy from nuclear fusion. Relaxing the equilibrium requirement could widen the range of isotopes used in fusion fuels permitting cleaner and less hazardous reactions that do not produce high energy neutrons. Here we propose and implement a means to drive fusion reactions between protons and boron-11 nuclei, by colliding a laser-accelerated proton beam with a laser-generated boron plasma. We report proton-boron reaction rates that are orders of magnitude higher than those reported previously. Beyond fusion, our approach demonstrates a new means for exploring low-energy nuclear reactions such as those that occur in astrophysical plasmas and related environments.

  9. Fusion reactions initiated by laser-accelerated particle beams in a laser-produced plasma

    The advent of high-intensity-pulsed laser technology enables the generation of extreme states of matter under conditions that are far from thermal equilibrium. This in turn could enable different approaches to generating energy from nuclear fusion. Relaxing the equilibrium requirement could widen the range of isotopes used in fusion fuels permitting cleaner and less hazardous reactions that do not produce high-energy neutrons. Here we propose and implement a means to drive fusion reactions between protons and boron-11 nuclei by colliding a laser-accelerated proton beam with a laser-generated boron plasma. We report proton-boron reaction rates that are orders of magnitude higher than those reported previously. Beyond fusion, our approach demonstrates a new means for exploring low-energy nuclear reactions such as those that occur in astrophysical plasmas and related environments. (authors)

  10. Simulations of Terrestrial in-situ Cosmogenic-Nuclide Production

    Reedy, R. C.; Nishiizumi, K.; Lal, D.; Arnold, J. R.; Englert, P. A. J.; Klein, J.; Middleton, R.; Jull, A. J. T.; Donahue, D. J.

    1994-01-01

    Targets of silicon and silicon dioxide were irradiated with spallation neutrons to simulate the production of long-lived radionuclides in the surface of the Earth. Gamma-ray spectroscopy was used to measure Be-7 and Na-22, and accelerator mass spectrometry was used to measure Be-10, C-14, and Al-26. The measured ratios of these nuclides are compared with calculated ratios and with ratios from other simulations and agree well with ratios inferred from terrestrial samples.

  11. Accelerator

    The invention claims equipment for stabilizing the position of the front covers of the accelerator chamber in cyclic accelerators which significantly increases accelerator reliability. For stabilizing, it uses hydraulic cushions placed between the electromagnet pole pieces and the front chamber covers. The top and the bottom cushions are hydraulically connected. The cushions are disconnected and removed from the hydraulic line using valves. (J.P.)

  12. The control mechanisms of erosion and weathering at basin scale from cosmogenic nuclides in river sediment

    Friedhelm von Blanckenburg;  

    2005-01-01

    The study of a sample of river sediment enables the determination of spatially averaged denudation rates that provide an exceptional perspective on erosion and weathering processes that have taken place within a landscape. These measurements are done with in-situ produced cosmogenic nuclides (e.g. 10Be, 26Al), mostly in quartz from alluvial sediment. Cosmogenic nuclides are produced when secondary cosmic rays interact with the very uppermost layer of the Earth’s surface. They are produced wit...

  13. Alpha-nuclides in nuclear power plants

    The behaviour of alpha-nuclides in nuclear power plants is subject of the investigations presented. The source of alpha-nuclides is a contamination with fissile material (so called tramp uranium or tramp fuel) which deposits on fuel rod surfaces and leads to the build-up of transuranium nuclides. The determination of a defect situation with fuel release as well as the quantification of the fissile material contamination background is given for BWR and PWR plants. The quantification of the fuel release and the tramp uranium background can be calculated with different, measurable nuclides in BWR and PWR plants. (orig.)

  14. Efficient and accurate depletion calculations via two-block decomposition of nuclide concentration vector

    Highlights: ► Nuclide density vector is decomposed into two blocks by effective decay constant. ► Short-lived nuclide block is solved by the general Bateman solution method. ► An importance concept, related to Bateman solution method, is introduced to reduce computational burden. ► Long-lived nuclide block is solved by the method of variation of parameters with matrix exponential with reduced norm. ► The new method shows significantly improved results compared to existing methods. - Abstract: A new method of depletion calculation is introduced by decomposing nuclide concentration vector into two blocks (short-lived nuclide block and long-lived nuclide block). For short-lived nuclide block calculation, general Bateman solution of each short-lived nuclide is used. An “importance” concept is introduced for selecting important parents for producing a particular short-lived nuclide so that computational burden for Bateman solution calculation is reduced. Long-lived nuclide block is solved by the method of variation of parameters, in which matrix exponentials are calculated efficiently since the norm of long-lived nuclide block matrix is small. The two-block decomposition method is tested on UO2 PWR fuel depletion problems and compared to existing depletion methods, i.e., ORIGEN code and Krylov subspace methods. The numerical results show that the two-block decomposition method gives much more accurate results than those of the ORIGEN code for similar computing time. For similar accuracy computing time of the two-block decomposition method is ∼10 times less than that of the Krylov subspace method

  15. Monte Carlo study of electron dose distributions produced by the elekta precise linear accelerator

    Background: Monte Carlo simulation of radiation transport is considered to be one of the most accurate methods of radiation therapy dose calculation and has ability to reduce the uncertainty in the calculated dose to a few percent. Aims: (1) To study the efficacy of the MCNP4C Monte Carlo code to simulate the dose distribution in a homogeneous medium produced by electron beams from the Elekta Precise linear accelerator. (2) To quantify the effect of introduction of various components to the simulated geometry for the above machine. Materials/Methods: Full Monte Carlo simulation of the detailed geometry of the Precise treatment head for 8 and 15 MeV energies and 10 x 10 applicator was performed. Experimental depth dose and lateral profiles at 2 cm depth were measured using a P-type diode detector with a 2.5 mm diameter. To quantify the effects of different parts of the treatment head, seven cases were simulated for a 15 MeV beam to reflect increasing levels of complexity, by step-wise introduction of beam divergence, primary and secondary scattering foils, secondary collimators, applicator, Mirror and Mylar screen. Results: The discrepancy between measured and calculated data is within 2 %/2 mm at both 8 and 15 MeV. In terms of the mean and most probable energies at the surface, the difference was < 0.2 MeV for the majority of cases and the maximum deviation was no more than 0.3 MeV. Conclusions: The results obtained with MCNP4C agree well with measured electron dose distributions. Inclusion of all the main components of the treatment head in the simulated geometry is necessary to avoid discrepancies of about 5 % compared to measurements. (authors)

  16. Nuclide inventory for nuclear fuel waste management

    To assist research projects in the Canadian Nuclear Fuel Waste Management Prgram, a compilation has been made of all the nuclides that are likely to be present in a nuclear fuel waste disposal vault and that are potentially hazardous to man during the post-closure phase. The compilation includes radiologically toxic and chemically toxic nuclides

  17. Multi-nuclide AMS system at the University of Tsukuba

    A multi-nuclide AMS system on the 12UD Pelletron tandem accelerator at the University of Tsukuba (Tsukuba AMS system) can measure environmental levels of long-lived radioisotopes of 14C, 26Al, 36Cl and 129I by employing a molecular pilot beam. AMS is an ultrasensitive technique for the study of long-lived radioisotopes, and stable isotopes at very low abundances. The high terminal voltage has an advantage in the detection of heavy radioisotopes. Much progress has been made in the development of new AMS techniques. For example, a standard deviation of the fluctuation for the 36Cl/Cl ratio is ± 2%, and the effective detection limit is better than 1x10-15. In recent years, the main research field of the 12UD Pelletron tandem accelerator has shifted to accelerator mass spectrometry (AMS) research from nuclear physics. This report presents an overview of the Tsukuba AMS system.

  18. Accelerator mass spectrometry of 36Cl produced by neutrons from the Hiroshima bomb

    Accelerator mass spectrometry was performed at the Munich tandem laboratory to determine 36Cl/Cl ratios of samples from a tombstone exposed to neutrons from the Hiroshima bomb. The ratios were determined from the surface to deeper positions. The depth profile of 36Cl/Cl can be used for estimating the neutron energy distribution and intensity near the hypocentre in Hiroshima. (author)

  19. Radioactive nuclides in the living environment

    There are several radioactive nuclides in the living environment, such as those existing since the creation of the earth, those coming from experimental nuclear explosions, and radiations of the cosmic rays. A lesson on these radioactive nuclides was considered useful for understanding the place of nuclear technology, and have been made on the title of 'Radioactive Nuclides in the Living Environment' in the general course of the Nuclear Engineering School of Japan Atomic Energy Research Institute. When the curriculum of the general course was modified in 1993, the lesson was left in a changed form. Thus, the textbook of the lesson is presented in this report. The contents are natural and artificial radioactive nuclides in the living environment and where they have come from etc. (author)

  20. Cosmogenic Nuclides Study of Large Iron Meteorites

    Hutzler, A.; Smith, T.; Rochette, P.; Bourles, D. L.; Leya, I.; Gattacceca, J.

    2014-09-01

    Six large iron meteorites were selected (Saint-Aubin, Mont-Dieu, Caille, Morasko, Agoudal, and Gebel Kamil). We measured stable and radiogenic cosmogenic nuclides, to study pre-atmospheric size, cosmic-ray exposure ages and terrestrial ages.

  1. Accelerator mass spectrometry of 36Cl produced by neutrons from the Hiroshima bomb.

    Kato, K; Habara, M; Yoshizawa, Y; Biebel, U; Haberstock, G; Heinzl, J; Korschinek, G; Morinaga, H; Nolte, E

    1990-10-01

    Accelerator mass spectrometry was performed at the Munich tandem laboratory to determine 36Cl/Cl ratios of samples from a tombstone exposed to neutrons from the Hiroshima bomb. The ratios were determined from the surface to deeper positions. The depth profile of 36Cl/Cl can be used for estimating the neutron energy distribution and intensity near the hypocentre in Hiroshima. PMID:1976726

  2. Measurement of Neutrons Produced by Beam-Target Interactions via a Coaxial Plasma Accelerator

    Cauble, Scott; Poehlmann, Flavio; Rieker, Gregory; Cappelli, Mark

    2011-10-01

    This poster presents a method to measure neutron yield from a coaxial plasma accelerator. Stored electrical energies between 1 and 19 kJ are discharged within a few microseconds across the electrodes of the coaxial gun, accelerating deuterium gas samples to plasma beam energies well beyond the keV energy range. The focus of this study is to examine the interaction of the plasma beam with a deuterated target by designing and fabricating a detector to measure neutron yield. Given the strong electromagnetic pulse associated with our accelerator, indirect measurement of neutrons via threshold-dependent nuclear activation serves as both a reliable and definitive indicator of high-energy particles for our application. Upon bombardment with neutrons, discs or stacks of metal foils placed near the deuterated target undergo nuclear activation reactions, yielding gamma-emitting isotopes whose decay is measured by a scintillation detector system. By collecting gamma ray spectra over time and considering nuclear cross sections, the magnitude of the original neutron pulse is inferred.

  3. Miniaturized acceleration sensors with in-plane polarized piezoelectric thin films produced by micromachining.

    Shanmugavel, Saravanan; Yao, Kui; Luong, Trung Dung; Oh, Sharon Roslyn; Chen, Yifan; Tan, Chin Yaw; Gaunekar, Ajit; Ng, Peter Hon Yu; Li, Marchy Hing Leung

    2011-11-01

    Miniaturized acceleration sensors employing piezoelectric thin films were fabricated through batch micromachining with silicon and silicon-on-insulator (SOI) wafers. The acceleration sensors comprised multiple suspension beams supporting a central seismic mass. Ferroelectric (Pb,La)(Zr,Ti) O(3) (PLZT) thin films were coated and in-plane polarized on the surfaces of the suspension beams for realizing electromechanical conversion through the piezoelectric effect. Interdigital electrodes were formed on the PLZT films and connected in parallel. Finite element analyses were conducted for the stress and strain distributions, providing guidance to the structural design, including optimizing electrode positioning for collecting the electrical output constructively. Uniformity of the beam thickness and sample consistency were significantly improved by using SOI wafers instead of silicon wafers. The measurement results showed that all the sensor samples had fundamental resonances of symmetric out-of-plane vibration mode at frequencies in the range of 8 to 35 kHz, depending on the sample dimensions. These sensors exhibited stable electrical outputs in response to acceleration input, achieving a high signal-to-noise ratio without any external amplifier or signal conditioning. PMID:22083762

  4. Alpha nuclides in nuclear power plants

    In a joint research project of VGB and AREVA NP GmbH the behavior of alpha nuclides in nuclear power plants has been investigated since 2005. The main source of alpha nuclides is core contamination with fissile material (so called tramp uranium or tramp fuel) which deposits on fuel rod surfaces and leads to the build-up of transuranium nuclides. Such alpha-nuclides are of special interest for health physics due to their high biological effectiveness. Having very high dose factors they lead to high dose weighting in case of incorporation. At NPC 2008 first results of the joint research project were presented concerning tramp fuel and its impact to alpha nuclides. The present publication will cover the ongoing results of this research project. A special focus is taken to deduce recommendations which allow plant operation personal to recognize situations in advance which can lead to enhanced appearance of alpha nuclides. Depending on the fuel conditions in the core and the activity level of fission products of the reactor coolant a better prediction of the alpha situation at the following outage and maintenance can be deduced. (author)

  5. Existence of the fifth unstable nuclide series

    张家骅

    1996-01-01

    The production of derived nuclides by the reaction of 238U with constant nuclear reactor neutron flux for long time is theoretically described.The concentration of each derived nuclide is zero at the beginning.then increases gradually and approaches a saturated value at a certain irradiation time.The whole system(including the parent nuclide 238U and all its derived nuclides)will be in a state of equilibrium.Upon the reaction with neutron flux,the whole system decreases its concentration at the same rate as 238U.It constitutes actually a new type of unstable nuclide series which is in owrk only in the presence of reactor neutron flux.It has been found that the amount of materials consumed by neutron flux reaction is almost converted entrely to fission product.This peculiar property is quite different from the well known four radioactive series,so that it is named the fifth unstable nuclide series.

  6. Measurements of the ambient dose equivalent of produced x-rays at the linear accelerator UNILAC of GSI

    At the UNILAC (UNIversal Linear ACcelerator) of the GSI (Gesellschaft fuer Schwerionenforschung, facility for the research with heavy ions, Darmstadt, Germany) two different pre-stripper sections deliver ions for further acceleration. One of these consists of an ECR - ion source (Electron Cyclotron Resonance), a RFQ (Radio Frequency Quadrupole) - and an IH (Interdigital H-field) - accelerating structure. After leaving the IH - structure the ions have a specific energy of 1.4 MeV/nucleon. The ion source and the accelerating structures produce x-rays during operation. Recently various accelerator facilities for carbon ion cancer treatment - consisting of linacs and synchrotrons - were planned, are under construction or are already in operation. It turned out that data of the radiation fields near linac structures (RFQ, IH) are scarce. The aim of this paper is to improve the knowledge of the production of x-rays in the ion source and the sections of the preaccelerator. Measurements have been performed by means of various passive and active dosemeter systems. For the passive dose measurements, TLD cards (Harshaw type with 4 TLD-700 elements) partially covered by absorption layers and surrounded by a polyethylene cylinder were used, in order to adapt their reading to the x-ray energy spectra at the measurement positions. A recently developed dosemeter at GSI suitable to measure the dose quantity H*(10) in the energy range 10 keV to several MeV was applied. The measurements are carried out in the vicinity of the ECR - ion source during the production of 7Li, 12C and 48Ca ion beams. A x-ray spectrum measured with a HPGe-detector near the ECR - ion source together with the dosemeter readings give hints on the fraction of the dose caused by low energy x-rays. Spatial dose distributions of the radiation fields around the RFQ and IH structures have been measured during their operation with different accelerating voltages (the produced radiation depends strongly on the

  7. Using a Tandem Pelletron accelerator to produce a thermal neutron beam for detector testing purposes.

    Irazola, L; Praena, J; Fernández, B; Macías, M; Bedogni, R; Terrón, J A; Sánchez-Nieto, B; Arias de Saavedra, F; Porras, I; Sánchez-Doblado, F

    2016-01-01

    Active thermal neutron detectors are used in a wide range of measuring devices in medicine, industry and research. For many applications, the long-term stability of these devices is crucial, so that very well controlled neutron fields are needed to perform calibrations and repeatability tests. A way to achieve such reference neutron fields, relying on a 3 MV Tandem Pelletron accelerator available at the CNA (Seville, Spain), is reported here. This paper shows thermal neutron field production and reproducibility characteristics over few days. PMID:26595777

  8. Measurements of the highest acceleration gradient for ions produced with a long laser pulse

    Margarone, Daniele; Krása, Josef; Láska, Leoš; Velyhan, Andriy; Mocek, Tomáš; Prokůpek, J.; Krouský, Eduard; Pfeifer, Miroslav; Gammino, S.; Torrisi, L.; Ullschmied, Jiří; Rus, Bedřich

    2010-01-01

    Roč. 81, č. 2 (2010), 02A506/1-02A506/4. ISSN 0034-6748 R&D Projects: GA MŠk(CZ) 7E08099; GA AV ČR IAA100100715 EU Projects: European Commission(XE) 212105 - ELI-PP Institutional research plan: CEZ:AV0Z10100523; CEZ:AV0Z20430508 Keywords : deconvolution * high-speed optical techniques * laser beam applications * plasma accelerators * plasma diagnostics * plasma light propagation Subject RIV: BH - Optics, Masers, Laser s Impact factor: 1.598, year: 2010

  9. Chloride isolation for accelerator mass spectrometry of 36Cl produced by atomic bomb neutrons

    Accelerator mass spectrometry was performed at the Munich tandem laboratory to determine the ratio of 36Cl/Cl in silicate rock samples exposed to neutrons of the Hiroshima atomic bomb. Chloride was chemically separated from silicate rock for this purpose. Five grams of silicate rock was fused with 30 g of sodium hydroxide and dissolved in 900 ml of water. The chloride in the resulting solution was spectrophotometrically determined. Chloride was precipitated as silver chloride by addition of appropriate amounts of silver nitrate, and silver chloride was then collected on a membrane filter. The chloride in the rock samples was thus isolated quantitatively. (author)

  10. Measurements and effects of backstreaming ions produced at bremsstrahlung converter target in Dragon-I linear induction accelerator

    Positive ions released from x-ray converter target impacted by electron beam of millimeter spot size can be trapped and accelerated in the incident beam's potential well. As the ions move upstream, the beam will be pinched first and then defocused at the target. Four Faraday cups are used to collect backstreaming ions produced at the bremsstrahlung converter target in Dragon-I linear induction accelerator (LIA). Experimental and theoretical results show that the backstreaming positive ions density and velocity are about 1021/m3 and 2-3 mm/μs, respectively. The theoretical and experimental results of electron beam envelope with ions and without ions are also presented. The discussions show that the backstreaming positive ions will not affect the electron beam focusing and envelope radius in Dragon-I LIA.

  11. Identification of heavy and superheavy nuclides using chemical separator systems

    Türler, Andreas

    1999-11-01

    With the recent synthesis of superheavy nuclides produced in the reactions 48Ca+238U and 48Ca+242,244Pu, much longer-lived nuclei than the previously known neutron-deficient isotopes of the heaviest elements have been identified. Half-lives of several hours and up to several years have been predicted for the longest-lived isotopes of these elements. Thus, the sensitivity of radiochemical separation techniques may present a viable alternative to physical separator systems for the discovery of some of the predicted longer-lived heavy and superheavy nuclides. The advantages of chemical separator systems in comparison to kinematic separators lie in the possibility of using thick targets, high beam intensities spread over larger target areas and in providing access to nuclides emitted under large angles and low velocities. Thus, chemical separator systems are ideally suited to study also transfer and (HI, αxn) reaction products. In the following, a study of (HI, αxn) reactions will be presented and prospects to chemically identify heavy and superheavy elements discussed.

  12. Factors affecting production rates of cosmogenic nuclides in extraterrestrial matter

    Reedy, R. C.

    2015-10-01

    Good production rates are needed for cosmic-ray-produced nuclides to interpret their measurements. Rates depend on many factors, especially the pre-atmospheric object's size, the location of the sample in that object (such as near surface or deep inside), and the object's bulk composition. The bulk composition affects rates, especially in objects with very low and very high iron contents. Extraterrestrial materials with high iron contents usually have higher rates for making nuclides made by reactions with energetic particles and lower rates for the capture of thermal neutrons. In small objects and near the surface of objects, the cascade of secondary neutrons is being developed as primary particles are being removed. Deep in large objects, that secondary cascade is fully developed and the fluxes of primary particles are low. Recent work shows that even the shape of an object in space has a small but measureable effect. Work has been done and continues to be done on better understanding those and other factors. More good sets of measurements in meteorites with known exposure geometries in space are needed. With the use of modern Monte Carlo codes for the production and transport of particles, the nature of these effects have been and is being studied. Work needs to be done to improve the results of these calculations, especially the cross sections for making spallogenic nuclides.

  13. ADAM12 produced by tumor cells rather than stromal cells accelerates breast tumor progression

    Frohlich, Camilla; Nehammer, Camilla; Albrechtsen, Reidar;

    2011-01-01

    ADAM12 deficiency reduces breast tumor progression in the PyMT model. However, the catalytic activity of ADAM12 appears to be dispensable for its tumor-promoting effect. Interestingly, we demonstrate that ADAM12 endogenously expressed in tumor-associated stroma in the PyMT model does not influence......Expression of ADAM12 is low in most normal tissues, but is markedly increased in numerous human cancers, including breast carcinomas. We have previously shown that overexpression of ADAM12 accelerates tumor progression in a mouse model of breast cancer (PyMT). In the present study, we found that...... tumor progression, but that ADAM12 expression by tumor cells is necessary for tumor progression in these mice. This finding is consistent with our observation that in human breast carcinoma ADAM12 is almost exclusively located in tumor cells and only rarely seen in the tumor-associated stroma. We...

  14. Chart of nuclides relating to neutron activation

    This chart is for frequent use in the prediction of the product species of neutron activation. The first edition of the chart has been made in 1976 after the repeated trial preparation. It has the following good points. (1) Any letter in chart is as large as one can read easily. [This condition has been obtained by the selection of items to be shown in chart. They are the name (the symbol of element, mass number, and half-life) of nuclide or of isomer, and the type of decay.]. (2) Decay product has been shown indirectly for branchings with two-step decay via short-lived daughter in an excited state. [This matter has been realized by use of the new mode of indication.] (3) Nuclides shown in chart are (a) naturally occurring nuclides and (b) nuclides formed from naturally occurring nuclides through one of the following reactions: (n, γ), (n, n'), (n, p), (n, α), (n, 2n), (n, pn), (n, 3n), (n, αn), (n, t), (n, 3He), (n, 2p), and (n, γ)(n, γ). In the revision of the first edition, some modes of indication have become a little simpler, and the isomers of shorter half-lives (0.1 - 1 μs) have been added. (author)

  15. Nuclide migration analysis in fractured rock

    This paper describes the results of PA studies considering heterogeneous fracture characteristics, for the purpose of contributing for the performance assessment of the natural barrier system PA in H12 report (The second progress report on research and development for the Geological Disposal of HLW in Japan). In this study, 3-D discrete fracture network model (DFN) and 1-D multiple pathways model is applied for 100 m scale of rock block. Although nuclide release rate calculated by DFN are widely distributed among the realizations, it is shown that several tens realizations are enough number to understand the stochastic characteristics of the nuclide release. From the data uncertainty analysis, there are no significant effects for the nuclide retardation in fracture geometry parameters such as fracture radius, density and etc. 1-D multiple pathways model is developed with focusing on the heterogeneity of the transmissivity, which has a large effect to the nuclide retardation effects. The nuclide release rate calculated by using 1-D multiple pathways model approximates to the results of DFN. This result also shows that the relatively large fractures/faults that connects disposal tunnel and downstream faults have an important role for performance assessment in natural barrier system. (author)

  16. Characterization of warm dense matter produced by laser-accelerated high-energy protons

    Nakatsutsumi, M.; Fuchs, J.; Mancic, A.; Robiche, J.; Renaudin, P.; Combis, P.; Dorchies, F.; Harmand, M.; Maynard, G.; Vassaux, J.; Mora, P.; Antici, P.; Fourmaux, S.; Audebert, P.

    2008-11-01

    Producing warm dense plasmas (WDM: solid density, few eV ˜ few 10s eV) is of interest for fundamental plasma physics or ICF. Laser-produced proton heating is of interest since they are short (LULI 100 TW facility to create and characterize WDM. We used, (i) 2D time-resolved optical self-emission of the heated target, (ii) surface expansion velocity measurement through phase measurements of a reflecting probe beam, and (iii) x-ray absorption spectroscopy. We showed that we could produce quasi-uniform heating of solids, as suited for e.g. EoS measurements. Time-resolved solid-liquid-plasma transition has been measured, as well as energy-loss of MeV protons in warm dense plasmas.

  17. Effects of X-Ray Irradiation Produced by Linear Accelerator on Biochemical Parameters of Irradiated Blood Units

    Irradiation of blood and cellular blood components is currently practiced in developed and in a few developing countries. The purpose of this procedure is the prevention of transfusion associated graft versus host disease in immunodeficient patients. Dedicated blood irradiators are only available at limited number of facilities in developing countries. Therefore, irradiation remains a limitedly available service due to excessive cost. This study aims to assess the biochemical changes in samples of packed red blood cell units irradiated using X-rays produced by linear accelerator (LINAC), used for radiotherapy, as an efficient and cost-effective solution for hospitals in developing countries instead of a dedicated device. X-rays generated by linear accelerator were used to irradiate red blood cell units. Each unit was divided to two equal portions, one portion was subjected to irradiation and the other portion used as control, irradiation process was performed in 3 minutes.Ph, potassium levels and percentage of hemolysis were analyzed on different storage periods. Progressive increase in potassium and hemolysis percentage and decrease in Ph was noted in the irradiated units. All parameters were within acceptable ranges indicating that the component is suitable for transfusion. From the above results we conclude that packed RBCs (pRBCs) irradiation using radiotherapy linear accelerator is an efficacious and cost-effective solution for most of the hospitals in developing countries

  18. Theoretical and numerical study of the expansion of a laser-produced plasma: high energy ion acceleration

    This work is a theoretical and numerical study on the high energy ion acceleration in laser created plasma expansion. The ion beams produced on the rear side of an irradiated foil reveal some characteristics (low divergence, wide spectra) which distinguish them from the ones coming from the front side. The discovery of these beams has renewed speculation for applications such as proton-therapy or proton radiography. The ion acceleration is performed via a self-consistent electrostatic field due to the charge separation between ions and hot electrons. In the first part of this dissertation, we present the fluid theoretical model and the hybrid code which simulates the plasma expansion. The numerical simulation of a recent experience on the dynamic of the electric field by proton radiography validates the theoretical model. The second part deals with the influence of an initial ion density gradient on the acceleration efficiency. We establish a model which relates the plasma dynamic and more precisely the wave breaking of the ion flow. The numerical results which predict a strong decrease of the ion maximum energy for large gradient length are in agreement with the experimental data. The Boltzmann equilibrium for the electron assumed in the first part has been thrown back into doubt in the third part. We adopt a kinetic description for the electron. The new version of the code can measure the Boltzmann law deviation which does not strongly modify the maximum energy that can reach the ions. (author)

  19. PRODUCTION CONSIDERATIONS FOR THE CLASSICAL PET NUCLIDES

    Nuclear Medicine is the specialty of medical imaging, which utilizes a variety of radionuclides incorporated into specific compounds for diagnostic imaging and therapeutic applications. During recent years, research efforts associated with this discipline have concentrated on the decay characteristics of particular radionuclides and the design of unique radiolabeled tracers necessary to achieve time-dependent molecular images. The specialty is expanding with specific Positron emission tomography (PET) and SPECT radiopharmaceuticals allowing for an extension from functional process imaging in tissue to pathologic processes and nuclide directed treatments. PET is an example of a technique that has been shown to yield the physiologic information necessary for clinical oncology diagnoses based upon altered tissue metabolism. Most PET drugs are currently produced using a cyclotron at locations that are in close proximity to the hospital or academic center at which the radiopharmaceutical will be administered. In November 1997, a law was enacted called the Food and Drug Administration Modernization Act of 1997 which directed the Food and Drug Administration (FDA) to establish appropriate procedures for the approval of PET drugs in accordance with section 505 of the Federal Food, Drug, and Cosmetic Act and to establish current good manufacturing practice requirements for such drugs. At this time the FDA is considering adopting special approval procedures and cGMP requirements for PET drugs. The evolution of PET radiopharmaceuticals has introduced a new class of ''drugs'' requiring production facilities and product formulations that must be closely aligned with the scheduled clinical utilization. The production of the radionuclide in the appropriate synthetic form is but one critical component in the manufacture of the finished radiopharmaceutical

  20. PRODUCTION CONSIDERATIONS FOR THE CLASSICAL PET NUCLIDES.

    FINN,R.; SCHLYER,D.

    2001-06-25

    Nuclear Medicine is the specialty of medical imaging, which utilizes a variety of radionuclides incorporated into specific compounds for diagnostic imaging and therapeutic applications. During recent years, research efforts associated with this discipline have concentrated on the decay characteristics of particular radionuclides and the design of unique radiolabeled tracers necessary to achieve time-dependent molecular images. The specialty is expanding with specific Positron emission tomography (PET) and SPECT radiopharmaceuticals allowing for an extension from functional process imaging in tissue to pathologic processes and nuclide directed treatments. PET is an example of a technique that has been shown to yield the physiologic information necessary for clinical oncology diagnoses based upon altered tissue metabolism. Most PET drugs are currently produced using a cyclotron at locations that are in close proximity to the hospital or academic center at which the radiopharmaceutical will be administered. In November 1997, a law was enacted called the Food and Drug Administration Modernization Act of 1997 which directed the Food and Drug Administration (FDA) to establish appropriate procedures for the approval of PET drugs in accordance with section 505 of the Federal Food, Drug, and Cosmetic Act and to establish current good manufacturing practice requirements for such drugs. At this time the FDA is considering adopting special approval procedures and cGMP requirements for PET drugs. The evolution of PET radiopharmaceuticals has introduced a new class of ''drugs'' requiring production facilities and product formulations that must be closely aligned with the scheduled clinical utilization. The production of the radionuclide in the appropriate synthetic form is but one critical component in the manufacture of the finished radiopharmaceutical.

  1. Exposure to radiation accelerates normal brain aging and produces deficits in spatial learning and memory

    Shukitt-Hale, B.; Casadesus, G.; Carey, A.; Rabin, B. M.; Joseph, J. A.

    Previous studies have shown that radiation exposure, particularly to particles of high energy and charge (HZE particles), produces deficits in spatial learning and memory. These adverse behavioral effects are similar to those seen in aged animals. It is possible that these shared effects may be produced by the same mechanism; oxidative stress damage to the central nervous system caused by an increased release of reactive oxygen species is likely responsible for the deficits seen in aging and following irradiation. Both aged and irradiated rats display cognitive impairment in tests of spatial learning and memory such as the Morris water maze and the radial arm maze. These rats have decrements in the ability to build spatial representations of the environment and they utilize non-spatial strategies to solve tasks. Furthermore, they show a lack of spatial preference, due to a decline in the ability to process or retain place (position of a goal with reference to a "map" provided by the configuration of numerous cues in the environment) information. These declines in spatial memory occur in measures dependent on both reference and working memory, and in the flexibility to reset mental images. These results show that irradiation with high-energy particles produces age-like decrements in cognitive behavior that may impair the ability of astronauts to perform critical tasks during long-term space travel beyond the magnetosphere. Supported by NASA Grants NAG9-1190 and NAG9-1529

  2. Neutron dosimetry of a medical accelerator which produces X-ray with high energy at Iran

    Polycarbonate detector and albedo-neuton dosemeters which is innovated at radiiation protection of Atomic Energy Organization of Iran was used to measure neutron doses in and out of radiation field. Dose distribution in radiation field, out of field and around the collimator, at the head of equipment, and dose topology in the field is determined. The response of these dosimeters to neutron contamination dose at the therapy room, the corridor, control room was investigated. Also response to recieved dose of the personnel is determined. According to the results obtained, by increasing photon doses at a constant size of the field 20 mutipliy 20 2 cm, the neutron dose at the center of X radiation field, lineary by 2.8 multiply 10-3 sv/sv X rar coefficient and in a fix field 40 multiply 40 cm2 by 3.1 multiply 10-3 sv/svX ray is increased. Also in constant photon dose, by changing the field size, neutron doses variation at the center of radiation field is investigated. Outside radiation field, neutron leakage percentage at different sectors of the head is obtained. using albedo-neutron dosemeters tracks density register for thermal, albedo and fast neutrons at therapy room for photon doses of 1 sv respectively was 37, 5710, 5364. Also at the same condition, at the extreme end of corridor the particle track density was 11, 885, 800. Track density registered for thermal albedo and fast neutron at the control room for one month respectively was 256, 786, 745. At the back of therapy room the track density for thermal neutrons was 14408 track per square centimeters for one month, but at the same period no particle tracks was observed. Finally, three personnel of accelerator's section was monitored by neutron dosemeters

  3. The nuclide inventory in SFR-1; Nuklidinventariet i SFR-1

    Ingemansson, Tor [ALARA Engineering, Skultuna (Sweden)

    2001-10-01

    This report is an account for a project carried out on behalf of the Swedish Radiation Protection Authority (SSI): 'Nuclide inventory in SFR-1' (The Swedish underground disposal facility for low and intermediate level reactor waste). The project comprises the following five sub-projects: 1) Measuring methods for nuclides, difficult to measure, 2) The nuclide inventory in SFR-1, 3) Proposal for nuclide library for SFR-1 and ground disposal, 4) Nuclide library for exemption, and 5) Characterising of the nuclide inventory and documentation for SFL waste. In all five sub-projects long-lived activity, including Cl-36, has been considered.

  4. Sampling soils for transuranic nuclides: a review

    A review of the literature pertinent to the sampling of soils for radionuclides is presented; emphasis is placed on transuranic nuclides. Sampling of soils is discussed relative to systems of heterogeneous distributions and varied particle sizes encountered in certain environments. Sampling methods that have been used for two different sources of contamination, global fallout, and accidental or operational releases, are included

  5. Measurement of Muon Antineutrino Oscillations with an Accelerator-Produced Off-Axis Beam.

    Abe, K; Andreopoulos, C; Antonova, M; Aoki, S; Ariga, A; Assylbekov, S; Autiero, D; Barbi, M; Barker, G J; Barr, G; Bartet-Friburg, P; Batkiewicz, M; Bay, F; Berardi, V; Berkman, S; Bhadra, S; Blondel, A; Bolognesi, S; Bordoni, S; Boyd, S B; Brailsford, D; Bravar, A; Bronner, C; Buizza Avanzini, M; Calland, R G; Cao, S; Caravaca Rodríguez, J; Cartwright, S L; Castillo, R; Catanesi, M G; Cervera, A; Cherdack, D; Chikuma, N; Christodoulou, G; Clifton, A; Coleman, J; Collazuol, G; Cremonesi, L; Dabrowska, A; De Rosa, G; Dealtry, T; Denner, P F; Dennis, S R; Densham, C; Dewhurst, D; Di Lodovico, F; Di Luise, S; Dolan, S; Drapier, O; Duffy, K E; Dumarchez, J; Dytman, S; Dziewiecki, M; Emery-Schrenk, S; Ereditato, A; Feusels, T; Finch, A J; Fiorentini, G A; Friend, M; Fujii, Y; Fukuda, D; Fukuda, Y; Furmanski, A P; Galymov, V; Garcia, A; Giffin, S G; Giganti, C; Gizzarelli, F; Gonin, M; Grant, N; Hadley, D R; Haegel, L; Haigh, M D; Hamilton, P; Hansen, D; Hara, T; Hartz, M; Hasegawa, T; Hastings, N C; Hayashino, T; Hayato, Y; Helmer, R L; Hierholzer, M; Hillairet, A; Himmel, A; Hiraki, T; Hirota, S; Hogan, M; Holeczek, J; Horikawa, S; Hosomi, F; Huang, K; Ichikawa, A K; Ieki, K; Ikeda, M; Imber, J; Insler, J; Intonti, R A; Irvine, T J; Ishida, T; Ishii, T; Iwai, E; Iwamoto, K; Izmaylov, A; Jacob, A; Jamieson, B; Jiang, M; Johnson, S; Jo, J H; Jonsson, P; Jung, C K; Kabirnezhad, M; Kaboth, A C; Kajita, T; Kakuno, H; Kameda, J; Karlen, D; Karpikov, I; Katori, T; Kearns, E; Khabibullin, M; Khotjantsev, A; Kielczewska, D; Kikawa, T; Kim, H; Kim, J; King, S; Kisiel, J; Knight, A; Knox, A; Kobayashi, T; Koch, L; Koga, T; Konaka, A; Kondo, K; Kopylov, A; Kormos, L L; Korzenev, A; Koshio, Y; Kropp, W; Kudenko, Y; Kurjata, R; Kutter, T; Lagoda, J; Lamont, I; Larkin, E; Laveder, M; Lawe, M; Lazos, M; Lindner, T; Liptak, Z J; Litchfield, R P; Li, X; Longhin, A; Lopez, J P; Ludovici, L; Lu, X; Magaletti, L; Mahn, K; Malek, M; Manly, S; Marino, A D; Marteau, J; Martin, J F; Martins, P; Martynenko, S; Maruyama, T; Matveev, V; Mavrokoridis, K; Ma, W Y; Mazzucato, E; McCarthy, M; McCauley, N; McFarland, K S; McGrew, C; Mefodiev, A; Mezzetto, M; Mijakowski, P; Minamino, A; Mineev, O; Mine, S; Missert, A; Miura, M; Moriyama, S; Mueller, Th A; Murphy, S; Myslik, J; Nakadaira, T; Nakahata, M; Nakamura, K G; Nakamura, K; Nakamura, K D; Nakayama, S; Nakaya, T; Nakayoshi, K; Nantais, C; Nielsen, C; Nirkko, M; Nishikawa, K; Nishimura, Y; Nowak, J; O'Keeffe, H M; Ohta, R; Okumura, K; Okusawa, T; Oryszczak, W; Oser, S M; Ovsyannikova, T; Owen, R A; Oyama, Y; Palladino, V; Palomino, J L; Paolone, V; Patel, N D; Pavin, M; Payne, D; Perkin, J D; Petrov, Y; Pickard, L; Pickering, L; Pinzon Guerra, E S; Pistillo, C; Popov, B; Posiadala-Zezula, M; Poutissou, J-M; Poutissou, R; Przewlocki, P; Quilain, B; Radicioni, E; Ratoff, P N; Ravonel, M; Rayner, M A M; Redij, A; Reinherz-Aronis, E; Riccio, C; Rojas, P; Rondio, E; Roth, S; Rubbia, A; Rychter, A; Sacco, R; Sakashita, K; Sánchez, F; Sato, F; Scantamburlo, E; Scholberg, K; Schoppmann, S; Schwehr, J; Scott, M; Seiya, Y; Sekiguchi, T; Sekiya, H; Sgalaberna, D; Shah, R; Shaikhiev, A; Shaker, F; Shaw, D; Shiozawa, M; Shirahige, T; Short, S; Smy, M; Sobczyk, J T; Sorel, M; Southwell, L; Stamoulis, P; Steinmann, J; Stewart, T; Suda, Y; Suvorov, S; Suzuki, A; Suzuki, K; Suzuki, S Y; Suzuki, Y; Tacik, R; Tada, M; Takahashi, S; Takeda, A; Takeuchi, Y; Tanaka, H K; Tanaka, H A; Terhorst, D; Terri, R; Thakore, T; Thompson, L F; Tobayama, S; Toki, W; Tomura, T; Touramanis, C; Tsukamoto, T; Tzanov, M; Uchida, Y; Vacheret, A; Vagins, M; Vallari, Z; Vasseur, G; Wachala, T; Wakamatsu, K; Walter, C W; Wark, D; Warzycha, W; Wascko, M O; Weber, A; Wendell, R; Wilkes, R J; Wilking, M J; Wilkinson, C; Wilson, J R; Wilson, R J; Yamada, Y; Yamamoto, K; Yamamoto, M; Yanagisawa, C; Yano, T; Yen, S; Yershov, N; Yokoyama, M; Yoo, J; Yoshida, K; Yuan, T; Yu, M; Zalewska, A; Zalipska, J; Zambelli, L; Zaremba, K; Ziembicki, M; Zimmerman, E D; Zito, M; Żmuda, J

    2016-05-01

    T2K reports its first measurements of the parameters governing the disappearance of ν[over ¯]_{μ} in an off-axis beam due to flavor change induced by neutrino oscillations. The quasimonochromatic ν[over ¯]_{μ} beam, produced with a peak energy of 0.6 GeV at J-PARC, is observed at the far detector Super-Kamiokande, 295 km away, where the ν[over ¯]_{μ} survival probability is expected to be minimal. Using a data set corresponding to 4.01×10^{20} protons on target, 34 fully contained μ-like events were observed. The best-fit oscillation parameters are sin^{2}(θ[over ¯]_{23})=0.45 and |Δm[over ¯]_{32}^{2}|=2.51×10^{-3}  eV^{2} with 68% confidence intervals of 0.38-0.64 and 2.26-2.80×10^{-3}  eV^{2}, respectively. These results are in agreement with existing antineutrino parameter measurements and also with the ν_{μ} disappearance parameters measured by T2K. PMID:27203315

  6. Characterization of an ion beam produced by extraction and acceleration of ions from a wire plasma source

    In this study we first model a DC low pressure wire plasma source and then characterize the properties of an ion gun derived from the plasma source. In order to study the properties of the derived ion gun, we develop a particle-in-cell code fitted to the modelling of the wire plasma source operation, and validate it by confrontation with the results of an experimental study. In light of the simulation results, an analysis of the wire discharge in terms of a collisional Child-Langmuir ion flow in cylindrical geometry is proposed. We interpret the mode transition as a natural reorganization of the discharge when the current is increased above a threshold value which is a function of the discharge voltage, the pressure and the inter-electrodes distance. In addition, the analysis of the energy distribution function of ions impacting the cathode demonstrates the ability to extract an ion beam of low energy spread around the discharge voltage assuming that the discharge is operated in its high pressure mode. An ion source prototype allowing the extraction and acceleration of ions from the wire source is then proposed. The experimental study of such a device confirms that, apart from a shift corresponding to the accelerating voltage, the acceleration scheme does not spread the ion velocity distribution function along the axis of the beam. It is therefore possible to produce tunable energy (0 - 5 keV) ion beams of various ionic species presenting limited energy dispersion ( 10 eV). The typical beam currents are about a few tens of micro-amperes, and the divergence of such a beam is on the order of one degree. A numerical modelling of the ion source is eventually conducted in order to identify potential optimizations of the concept. (author)

  7. Cosmogenic nuclides 7Be and 10Be in rains collected in Tokyo

    Concentrations of cosmogenic nuclides 7Be and 10Be in rains collected in Tokyo during the last 20 years were determined by γ-ray spectrometry and accelerator mass spectrometry. For the seasonal variation, the highest values for 10Be flux and 10Be/7Be ratio were observed in spring, February to April, and they decreased till the lowest values in autumn. On the other hand, there were not so clear feature for 7Be flux. These feature were caused by the transport of stratospheric air with high 10Be concentration into the troposphere. The annual fluxes for 7Be and 10Be change cyclic, and the average for 7Be and 10Be were ∼3 and ∼10 (x10-2 atom cm-2 s-1) with ±50% and ±30% deviation, respectively. Comparing to the sunspot number as the index of cosmic ray intensity, the annual 7Be flux was anti-correlated, and also the annual 10Be flux was anti-correlated with two years delay. This imply that the most part of 7Be atoms deposited in Tokyo were produced in the troposphere, and the fairly large part of 10Be atoms deposited in Tokyo were produced in the stratosphere. (author)

  8. Clover root exudate produces male-biased sex ratios and accelerates male metamorphic timing in wood frogs.

    Lambert, Max R

    2015-12-01

    In amphibians, abnormal metamorph sex ratios and sexual development have almost exclusively been considered in response to synthetic compounds like pesticides or pharmaceuticals. However, endocrine-active plant chemicals (i.e. phytoestrogens) are commonly found in agricultural and urban waterways hosting frog populations with deviant sexual development. Yet the effects of these compounds on amphibian development remain predominantly unexplored. Legumes, like clover, are common in agricultural fields and urban yards and exude phytoestrogen mixtures from their roots. These root exudates serve important ecological functions and may also be a source of phytoestrogens in waterways. I show that clover root exudate produces male-biased sex ratios and accelerates male metamorphosis relative to females in low and intermediate doses of root exudate. My results indicate that root exudates are a potential source of contaminants impacting vertebrate development and that humans may be cultivating sexual abnormalities in wildlife by actively managing certain plant species. PMID:27019728

  9. Plasma accelerators

    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)

  10. Research methods for evaluation absorbing and accumulating nuclides of plant

    This paper reviewed the recent studies on plants absorption and accumulation of nuclides and divided the studies to several aspects such as monitoring, mechanism restoration, and stressing based on their purpose. The paper also summarized the methods for selection and treatment of nuclides, plants preparation, nuclides test and evaluation. (authors)

  11. Synthesis and study of heavy neutron-rich nuclides

    The recent progresses made in the synthesis and studies of heavy neutron-rich nuclides are reviewed. The astrophysical implications of the decay properties and nuclear structure of the heavy neutron-rich nuclides are discussed. The production reactions, separation and identification of the nuclides are summarized. (author). 42 refs., 10 figs., 2 tabs

  12. Characterization of Vertical Accelerations Experienced by Older People Attending an Aerobics Class Designed to Produce High Impacts.

    Hannam, Kimberly; Deere, Kevin; Worrall, Sue; Hartley, April; Tobias, Jon H

    2016-04-01

    The purpose of this study was to establish the feasibility of using an aerobics class to produce potentially bone protective vertical impacts of ≥ 4g in older adults and to determine whether impacts can be predicted by physical function. Participants recruited from older adult exercise classes completed an SF-12 questionnaire, short physical performance battery, and an aerobics class with seven different components, performed at low and high intensity. Maximum g and jerk values were identified for each activity. Forty-one participants (mean 69 years) were included. Mean maximal values approached or exceeded the 4g threshold for four of the seven exercises. In multivariate analyses, age (-0.53; -0.77, -0.28) (standardized beta coefficient; 95% CI) and 4-m walk time (-0.39; -0.63, -0.16) were inversely related to maximum g. Aerobics classes can be used to produce relatively high vertical accelerations in older individuals, although the outcome is strongly dependent on age and physical function. PMID:26421605

  13. Neutron multiplicities for the transplutonium nuclides

    This paper continues, with respect to the transplutonium nuclides, earlier efforts to collate and evaluate data from the scientific literature on the prompt neutron multiplicity distribution from fission and its first moment = ΣnuPnu. The isotopes considered here for which P/sub nu/ and or data (or both) were found in the literature are of americium (Am), curium (Cm), berkelium (Bk), californium (Cf), einsteinium (Es), fermium (Fm), and nobelium (No)

  14. Prompt neutron multiplicities for the transplutonium nuclides

    In reponse to a need of the safeguards community, we have begun an evaluation effort to upgrade the values of the prompt neutron emission multiplicity distribution from fission, Psub(upsilon), and its average value . The reported Psub(upsilon) for various transplutonium nuclides have been renormalized via an independent evaluation of . Recommended values and uncertainties are given for the newly evaluated and Psub(upsilon). (author)

  15. Synthesis of final disposal related nuclides

    Posiva Oy manages the disposal of spent nuclear fuel from the Loviisa and Olkiluoto nuclear power plants (NPP). When the spent nuclear fuel is removed from the reactor it is stored in the cooling pools at the NPP units for approximately five years. After the first cooling period the spent nuclear fuel is transported to the interim storage (KPA) at the NPP's to cool down in water pools at least for 20-30 years. Generic radionuclide inventory calculations have been made for the spent nuclear fuel with a cooling period of 30 years. These calculations are the basis for Posiva's operational safety, safety case and decay heat power and criticality calculations. Validating the calculated radionuclide inventories with radiochemical analyses is advisable. The most important nuclides, both radioactive and stable, from the radiation and operational safety, long-term safety, decay heat power and criticality calculations point of view are listed. Also the nuclides possible to be assessed by Studsvik are listed. The conclusion is that the nuclides proposed by Studsvik in 2011 are recommended for radiochemical analyses of spent nuclear fuel. (orig.)

  16. Synthesis of final disposal related nuclides

    Haavisto, T. [Teollisuuden Voima Oyj, Eurajoki (Finland)

    2014-04-15

    Posiva Oy manages the disposal of spent nuclear fuel from the Loviisa and Olkiluoto nuclear power plants (NPP). When the spent nuclear fuel is removed from the reactor it is stored in the cooling pools at the NPP units for approximately five years. After the first cooling period the spent nuclear fuel is transported to the interim storage (KPA) at the NPP's to cool down in water pools at least for 20-30 years. Generic radionuclide inventory calculations have been made for the spent nuclear fuel with a cooling period of 30 years. These calculations are the basis for Posiva's operational safety, safety case and decay heat power and criticality calculations. Validating the calculated radionuclide inventories with radiochemical analyses is advisable. The most important nuclides, both radioactive and stable, from the radiation and operational safety, long-term safety, decay heat power and criticality calculations point of view are listed. Also the nuclides possible to be assessed by Studsvik are listed. The conclusion is that the nuclides proposed by Studsvik in 2011 are recommended for radiochemical analyses of spent nuclear fuel. (orig.)

  17. Reactor and /or accelerator: general remarks on strategic considerations in sourcing/producing radiopharmaceuticals and radiotracer for the Philippines

    The most important sources of radionuclides in the world are particle accelerators and nuclear reactors. Since the late 1940's many radiotracers and radiopharmaceuticals have been innovated and conceived, designed, produced and applied in important industrial and clinical/ biomedical settings. For example in the health area, reactor-produced radionuclides have become indispensable for diagnostic imaging involving, in its most recent and advanced development, radioimmunoscintigraphy, which exploits the exquisite ligand-specificity of monoclonal antibodies, reagents which in turn are the products of advances in biotechnology. Thus far, one of the most indispensable radiopharmaceuticals has been 99mTc, which is usually obtained as a daughter decay product of 99Mo. In January 1991, some questions about the stability of the worldwide commercial supply of 99Mo became highlighted when the major commercial world producer of 99Mo, Nordion International, shut down its facilities temporarily in Canada due to contamination in its main reactor building (see for instance relevant newsbrief in J. Nuclear Medicine (1991): 'Industry agrees to join DOE study of domestic moly-99 production'). With the above background, my remarks will attempt to open discussions on strategic considerations relevant to questions of 'self reliance' in radiotracers/radiopharmaceutical production in the Philippines. For instance, the relevant question of sourcing local radionuclide needs from a fully functioning multipurpose cyclotron facility within the country that will then supply the needs of the local industrial, biomedical (including research) and health sectors; and possibly, eventually acquiring the capability to export to nearby countries longer-lived radiotracers and radiopharmaceuticals

  18. Low-energy structure of neutron-rich S, Cl and Ar nuclides through β decay

    Detailed nuclear structure studies of 20≤N≤28, 14≤Z≤20 nuclides have been limited until recently due to the lack of a good production mechanism. With the advent of projectile fragmentation facilities these nuclides can now be produced, separated, and studied in detail using several different techniques. Two recent experiments conducted at the NSCL have provided information on the β decays of 39,40,41P, 40,41,42,43S, and 42,43,44,45Cl, which will be used to establish level schemes for the daughter nuclides. These will provide a better understanding of the systematic change from spherical to deformed shapes within the proton sd and neutron fp shells. Presented here are preliminary results from these experiments with an emphasis placed on the structure of the deformed nucleus 40S

  19. Investigation of heavy neutron-rich nuclides with time-resolved Schottky mass spectrometry

    Neutron-rich heavy nuclides, which were produced by fragmentation of a 197Au primary beam and separated in the FRS, were investigated with Schottky Mass Spectrometry (SMS) using the GSI ESR. Masses for nine nuclides were measured for the first time: 181,183Lu, 185,186Hf, 187,188Ta, 191W and 192,193Re. Also, the accuracy of the mass values for three other nuclides (189,190W and 195Os) was significantly improved. The new data was used for nuclear structure investigations by studying the behavior of two neutron separation energies, S2n, and comparing them with the energies of the first excited 2+ states.

  20. Low-energy structure of neutron-rich S, Cl and Ar nuclides through [beta] decay

    Winger, J.A.; Yousif, H.H.; Ma, W.C.; Ravikumar, V.; Lui, W.; Phillips, S.K.; Piercey, R.B. (Department of Chemistry, Michigan State University, East Lansing, Michigan 48824 (United States) National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States))

    1998-12-01

    Detailed nuclear structure studies of 20[le]N[le]28, 14[le]Z[le]20 nuclides have been limited until recently due to the lack of a good production mechanism. With the advent of projectile fragmentation facilities these nuclides can now be produced, separated, and studied in detail using several different techniques. Two recent experiments conducted at the NSCL have provided information on the [beta] decays of [sup 39,40,41]P, [sup 40,41,42,43]S, and [sup 42,43,44,45]Cl, which will be used to establish level schemes for the daughter nuclides. These will provide a better understanding of the systematic change from spherical to deformed shapes within the proton sd and neutron fp shells. Presented here are preliminary results from these experiments with an emphasis placed on the structure of the deformed nucleus [sup 40]S. [copyright] [ital 1998 American Institute of Physics.

  1. Low-energy structure of neutron-rich S, Cl and Ar nuclides through {beta} decay

    Winger, J.A.; Yousif, H.H.; Ma, W.C.; Ravikumar, V.; Lui, W.; Phillips, S.K.; Piercey, R.B. [Department of Chemistry, Michigan State University, East Lansing, Michigan 48824 (United States)]|[National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States)

    1998-12-01

    Detailed nuclear structure studies of 20{le}N{le}28, 14{le}Z{le}20 nuclides have been limited until recently due to the lack of a good production mechanism. With the advent of projectile fragmentation facilities these nuclides can now be produced, separated, and studied in detail using several different techniques. Two recent experiments conducted at the NSCL have provided information on the {beta} decays of {sup 39,40,41}P, {sup 40,41,42,43}S, and {sup 42,43,44,45}Cl, which will be used to establish level schemes for the daughter nuclides. These will provide a better understanding of the systematic change from spherical to deformed shapes within the proton sd and neutron fp shells. Presented here are preliminary results from these experiments with an emphasis placed on the structure of the deformed nucleus {sup 40}S. {copyright} {ital 1998 American Institute of Physics.}

  2. The preparation of organic radiopharmaceuticals and labelled compounds using short-lived cyclotron-produced radionuclides

    Accelerator-produced nuclides and radiopharmaceutical production are discussed with examples of pertinent methods of isotope production, methods of incorporation into organic molecules, and the general problems attandant on the production and use of these materials in this new and interdisciplinary effort. The literature is surveyed with stress being given to the use of 11C, 13N and 15O. 205 references are included. (author)

  3. Mass Evaluation for Proton Rich Nuclides

    Wang, M. [Institute of Modern Physics, Chinese Academy of Sciences, 730000 Lanzhou (China); CSNSM-IN2P3, Batiment 104,108, 91405 Orsay Campus (France); Audi, G. [CSNSM-IN2P3, Batiment 104,108, 91405 Orsay Campus (France); Xu, X. [Institute of Modern Physics, Chinese Academy of Sciences, 730000 Lanzhou (China); CSNSM-IN2P3, Batiment 104,108, 91405 Orsay Campus (France); Graduate University of Chinese Academy of Sciences, Beijing, 100049 (China); Pfeiffer, B. [GSI Helmholtzzentrum fuer Schwerionenforschung, Planckstr. 1, D-64291 Darmstadt (Germany); Kondev, F. G. [Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, Illinois 60439 (United States)

    2011-11-30

    The Atomic mass evaluation (AME) provides the reliable resource for the values related to atomic masses. Since the publication of the latest version of AME in 2003, many developments for atomic mass determination have been done and important results changed significantly our knowledge. A preliminary version of AME was released in April 2011, and an official version is foreseen to be published in early 2013. The general status of AME is presented and some specific features of AME for proton-rich nuclides are discussed.

  4. Mass Evaluation for Proton Rich Nuclides

    The Atomic mass evaluation (AME) provides the reliable resource for the values related to atomic masses. Since the publication of the latest version of AME in 2003, many developments for atomic mass determination have been done and important results changed significantly our knowledge. A preliminary version of AME was released in April 2011, and an official version is foreseen to be published in early 2013. The general status of AME is presented and some specific features of AME for proton-rich nuclides are discussed.

  5. Nuclide-specific monitoring of airborne radioactivity

    Since the end of the seventies the Landesanstalt fuer Umweltschutz Baden-Wuerttemberg ist operating two radioaerosol monitoring stations at the border in the opposite of foreign nuclear power plants. Since the end of the eighties six similar monitoring stations were built up for measuring activity in breathing air in the common environment in Baden-Wuerttemberg. A special filtersystem allows measuring the activity concentration of up to 99 nuclides. The measuring system was optimized by advanced PC-technology, a multitasking operating system and a special software for users and gamma-spectroscopy. These increased the average availability of all monitoring stations to 96% in 1996. (orig.)

  6. Prompt neutron multiplicities for the transplutonium nuclides

    The direct determination of the average prompt neutron emission values is reviewed, and a method of comparing different sites of neutron emission multiplicity distribution values is described. Measured and recommended values are tabulated for these nuclides: 241Am, 242Am, 242Cm, 243Cm, 244Cm, 246Cm, 247Cm, 248Cm, 250Cm, 245Cm, 249Bk, 246Cf, 249Cf, 250Cf, 252Cf, 254Cf, 251Cf, 253Es, 254Es, 244Fm, 246Fm, 255Fm, 252No, 254Fm, 256Fm, 257Fm. 59 refs., 24 tabs

  7. Vertical migration of nuclides seeped from an uranium tailings impoundment

    After 31 year operation of an uranium tailings impoundment, sub-clayey samples beneath its bottom were taken for determining concentration distribution of U, Th and Ra seeped from the impoundment. For fitting nuclide migration, one dimensional convection-dispersion model of nuclide migration in groundwater was applied, and parameters were measured such as particle size of tailings, leaching factor of nuclides from tailings and distribution coefficients of nuclides in sub-clay. Results indicate that fine tailings are the main portion of tailings, and possess higher specific activities and lower leaching factor than coarse tailings. The sub-clay has a strong adsorption ability to nuclides, and distribution coefficients of U, Th and Ra are 62, 1.3 x 103 and 9.8 x 102 mL/g, respectively. The natural and man-made sub-clay layers beneath the impoundment can reduce effectively nuclides seepage and migration. (authors)

  8. Mechanism of fission of neutron-deficient actinoids nuclides

    Sueki, Keisuke; Nakahara, Hiromichi [Tokyo Metropolitan Univ., Hachioji (Japan). Faculty of Science; Tanase, Masakazu; Nagame, Yuichiro; Shinohara, Nobuo; Tsukada, Kazuaki

    1996-01-01

    A heavy ion reaction ({sup 19}F+{sup 209}Bi) is selected. The reaction produces neutron-deficient {sup 228}U which is compound nucleus with a pair of Rb(z=37) and Cs(Z=55). Energy dissipation problem of nucleus was studied by measuring the isotope distribution of two fissile nuclides. Bismuth metal evaporated on aluminium foil was irradiated by {sup 19}F with the incident energy of 105-128 MeV. We concluded from the results that the excess energy of reaction system obtained with increasing the incident energy is consumed by (1) light Rb much more than Cs and (2) about 60% of energy is given to two fission fragments and the rest 40% to the translational kinetic energy or unknown anomalous {gamma}-ray irradiation. (S.Y.)

  9. Cosmogenic nuclide production rate systematics in terrestrial materials: Present knowledge, needs and future actions for improvement

    The growing applications of cosmogenic nuclides produced in the Earth's atmosphere, and in situ in a variety of terrestrial materials, as tracers in a wide ranging Earth science problems, has put a greater demand on accurate determination of the nuclide production rates in a variety of targets exposed in different settings on the Earth in the troposphere. The present state of our knowledge of cosmogenic production rates is reviewed briefly, in conjunction with the phenomenological and theoretical framework for: (i) the cosmic ray flux incident in the near Earth environment, (ii) the nucleonic cascade set off in the Earth's atmosphere by the primary cosmic radiation, and (iii) the rate for production of nuclides in terrestrial materials, in widely different settings. These considerations set the stage for the diverse questions, which must be taken into account for determining the source functions of isotopic changes in terrestrial materials. We discuss the different approaches which have been adopted earlier to obtain the source strengths of nuclear interacting particles of the cosmic radiation, and direct measurements of nuclide production rates made by exposing targets to cosmic radiation at sea level and at mountain altitudes. We show that rapid progress in determining nuclide source functions with sufficient information on temporal variability is indeed expected in the near future as a result of: (i) dramatic improvements in the past 2-3 decades in our understanding of the character of propagation of cosmic radiation within the heliosphere, (ii) experiments now being conducted by a few groups to determine the source strengths of cosmic ray slow neutrons, and nuclide production rates in cosmic ray exposed targets, and finally (iii) the emergence of better nuclear codes which deal with the development of nucleonic cascades in the Earth's atmosphere

  10. NUCLEUS-CHART. Chart of the Nuclides

    Atomic Mass Data Center [Orsy (France)

    1998-05-05

    Nucleus is an interactive PC-based graphical viewer of NUBASE nuclear property data. NUBASE contains experimentally known nuclear properties, together with some values that have been estimated from extrapolation of experimental data for 3010 nuclides. NUBASE also contains data on those isomeric states that have half-lives greater than 1 millisecond; there are 669 such nuclides of which 58 have more than one isomeric state. The latest version of NUCLEUS-CHART has been corrected to include the names and the chemical symbols of the elements 104 to 109 that have been finally adopted by the Commission on Nomenclature of Inorganic Chemistry (CNIC) of the International Union of Pure and Applied Chemistry (IUPAC). They differ from those recommended by the same commission a few years before and that were widely used in the evaluations AME`95 and NUBASE`97. It results in some shuffling of the names and symbols, that may cause confusion in the near future. At AMDC we`ll be as careful as possible to try to avoid such confusion. In advance we apologize if any will occur in the future and recommend the user to always double check these few names.

  11. Deduction of interfering nuclides in radioactive measurement of 87Kr

    The radioactivity of short-lived nuclide 87Kr is interfered by 85mKr and 125Xe when it is measured by internal gas proportional counting. It is difficult to separate interfering nuclides from the gas sample. In this work, a series of data were measured according to the characteristic that different nuclides have different half-life, the radioactivity of 87Kr is obtained by calculating coefficients of linear equations by the least square method. (authors)

  12. Mass measurements on short-lived Cd and Ag nuclides at the online mass spectrometer ISOLTRAP

    of the produced material at A = 99. It has been shown that the mass of 99Cd strongly affects the A = 99 production in an X-ray burst model, and that uncertainties have been significantly reduced from more than an order of magnitude to about a factor of 3. The dominant source of uncertainty is now the mass of 100In. In principle, other uncertainties will also contribute. These include those of masses of lighter Cd isotopes, where similar rp-process branchpoints occur and which might affect feeding into the 99Cd branchpoint. In addition, nuclear reaction rate uncertainties will also play a role. However, as reaction rates affect branchings in a linear fashion, while mass differences enter exponentially, mass uncertainties will tend to dominate [Sch06]. Also, which reaction rates are important depends largely on nuclear masses. For example, for low Sp(100In) a (p,γ)-(γ,p) equilibrium will be established between 99Cd and 100In and the 100In(p,γ) reaction rate would affect the A = 99 production, while for larger Sp(100In) the 99Cd(p,γ) reaction rate might be more relevant. Therefore, the mass uncertainties should be addressed first. Once they are under control, further improvements might be possible by constraining proton capture rates. The presented results are relevant for any rp-process scenario with a reaction flow through the 99Cd region. Here, an X-ray burst model has been used to investigate in detail the impact of the present measurements on such an rp process. The νp process in core collapse supernovae might be another possible scenario for an rp process in the 99Cd region. It it is planed to also explore whether in that case mass uncertainties have a similar impact on the final composition. On the neutron-rich side of the valley of stability for the Cd and Ag chains of nuclides, the r process has not yet been reached. Further technical development on suppression of contaminants are required. This includes improvements on the ISOLDE side, e.g., by improving

  13. Transmutation of actinides from light water reactors in modular high-temperature reactors for the reduction of long-lived nuclides; Verbrennung von Aktiniden aus Leichtwasserreaktoren in modularen Hochtemperaturreaktoren zur Reduzierung langlebiger Nuklide

    Meier, Astrid

    2012-05-15

    Only one of many different ways to produce electric power is the Light Water Reactor (LWR).This reactor produces high level long-lived and radiotoxic nuclides like Plutonium and Minore Actinides (Neptunium, Americium, Curium,..), which have to be safely isolated and controlled in a final storage over a long time. Thus, many projects worldwide concentrate on the transformation of these long-lived nuclides into short-lived nuclides by transmutation and fission processes. Here, mainly accelerator driven systems and Generation-IV-reactors, like the graphite moderated, Helium cooled High Temperature Reactor (HTR), are in focus of research. The main advantages of the HTR are the fuel structure, which allows high burnups and the inherent safety. In case of a Loss Of Cooling Accident (LOCA), the decay heat will be dissipated without any active cooling system. This passive heat transfer is high enough to stay below the upper temperature limit in the fuel. Therefore, the fuel structure stays intact and the fission products retain inside the fuel. In this thesis, the long-lived nuclides like Plutonium, Neptunium and Americium, extracted from the spent LWR fuel, will be reused in a fresh fuel element for the HTR. To achieve the aim of reducing these nuclides and their radiotoxicity, the HTR has to operate at the highest possible burnup. Therefore parameters, like e.g. the fuel temperature or the power density distribution and also the behaviour in case of an accident have to be comparable to the HTR loaded with uranium fuel. The European Union project ''Plutonium and Minore Actinide Waste Management'' (PuMA) is the origin for the used reference reactor geometry, the fuel structure as well as the nuclide densities in the Plutonium and Minor Actinides fuel. The reactor design of this project is almost identical to the South African reactor concept with 400 MW{sub th} thermal power and an inner graphite column (Pebble Bed Modular Reactor PBMR-400).For

  14. A comparison of rat SPECT images obtained using 99mTc derived from 99Mo produced by an electron accelerator with that from a reactor

    Galea, R.; Wells, R. G.; Ross, C. K.; Lockwood, J.; Moore, K.; Harvey, J. T.; Isensee, G. H.

    2013-05-01

    Recent shortages of molybdenum-99 (99Mo) have led to an examination of alternate production methods that could contribute to a more robust supply. An electron accelerator and the photoneutron reaction were used to produce 99Mo from which technetium-99m (99mTc) is extracted. SPECT images of rat anatomy obtained using the accelerator-produced 99mTc with those obtained using 99mTc from a commercial generator were compared. Disks of 100Mo were irradiated with x-rays produced by a 35 MeV electron beam to generate about 1110 MBq (30 mCi) of 99Mo per disk. After target dissolution, a NorthStar ARSII unit was used to separate the 99mTc, which was subsequently used to tag pharmaceuticals suitable for cardiac and bone imaging. SPECT images were acquired for three rats and compared to images for the same three rats obtained using 99mTc from a standard reactor 99Mo generator. The efficiency of 99Mo-99mTc separation was typically greater than 90%. This study demonstrated the delivery of 99mTc from the end of beam to the end user of approximately 30 h. Images obtained using the heart and bone scanning agents using reactor and linac-produced 99mTc were comparable. High-power electron accelerators are an attractive option for producing 99Mo on a national scale.

  15. High-power, high-brightness pseudospark-produced electron beam driven by improved pulse line accelerator

    A high power (200KV), intense current density, low emittance (71mmmrad), high brightness (8x1010A/m rad) electron beam was generated in the 10cm long, high-voltage-resistive multi-gap hollow cathode pseudospark chamber filled with 15pa nitrogen and driven by an improved pulse line accelerator. The beam was ejected with the 1mm diameter, the 2.2KA beam current, and the 400ns pulse length, and could propagated 20cm in the drift tube. At a distance of 5cm from the anode it penetrated consecutively an acid-sensitive discoloring film and a 0.05mm-thick copper foil both stuck closely, left 0.6mm and 0.3mm holes on them, respectively. That 10 shots on an acid-sensitive film produced a hole of 1.6mm at 7cm downstream of anode showed its good repeatability. After 60 shots the pseudospark discharge chamber was disassembled and observed that almost no destructive damage traces left on the surfaces of its various electrodes and insulators. But on almost all the surfaces of changeable central hole parts installed on intermediate electrodes there are traces of electron emission from the sides facing the anode and of bombardment on the sides facing the cathode, in contrast with which on the front- and back-surfaces of hollow cathode no visible traces of electron emission from then was observed. In addition, there were different tints, strip-like regions on the side of anode facing the cathode. Another interesting phenomenon was that there were a set of concentric circular or elliptical ring pattern on the acid-sensitive discoloring film got at 5cm from the anode and observed tinder a metallograph. It seems that the pseudospark electron beam is Laminar beam i.e, being possessed of a multi-layer structure, at least in the case of multi-gap pseudospark discharge chamber. It was found experimentally that the quality of pseudospark electron beam is much better than that of the cold-cathode electron beam

  16. Model for large scale circulation of nuclides in nature, 1

    Ohnishi, Teruaki

    1988-12-01

    A model for large scale circulation of nuclides was developed, and a computer code named COCAIN was made which simulates this circulation system-dynamically. The natural environment considered in the present paper consists of 2 atmospheres, 8 geospheres and 2 lithospheres. The biosphere is composed of 4 types of edible plants, 5 cattles and their products, 4 water biota and 16 human organs. The biosphere is assumed to be given nuclides from the natural environment mentioned above. With the use of COCAIN, two numerical case studies were carried out; the one is the study on nuclear pollution in nature by the radioactive nuclides originating from the past nuclear bomb tests, and the other is the study on the response of environment and biota to the pulse injection of nuclides into one compartment. From the former case study it was verified that this model can well explain the observation and properly simulate the large scale circulation of nuclides in nature.

  17. Model for large scale circulation of nuclides in nature, 1

    A model for large scale circulation of nuclides was developed, and a computer code named COCAIN was made which simulates this circulation system-dynamically. The natural environment considered in the present paper consists of 2 atmospheres, 8 geospheres and 2 lithospheres. The biosphere is composed of 4 types of edible plants, 5 cattles and their products, 4 water biota and 16 human organs. The biosphere is assumed to be given nuclides from the natural environment mentioned above. With the use of COCAIN, two numerical case studies were carried out; the one is the study on nuclear pollution in nature by the radioactive nuclides originating from the past nuclear bomb tests, and the other is the study on the response of environment and biota to the pulse injection of nuclides into one compartment. From the former case study it was verified that this model can well explain the observation and properly simulate the large scale circulation of nuclides in nature. (author)

  18. Application of general-purpose radiation transport code into study for laser-produced plasma ions acceleration

    A general-purpose Monte Carlo particle and heavy ion transport code system (PHITS), which consists of various quantum dynamics models, was used to study laser-driven ion acceleration. Our simulation reasonably predicted not only the laser driven ion's trajectories detected by the monitors but also the radiation shielding of these particles. (author)

  19. Waste management of radioactive residual material at a research center operating a heavy ion accelerator

    Since the 70th GSI in Darmstadt succesfully operates a large heavy ion accelerator. Limited amounts of Radioactive residual material and waste is produced in addition to great and numerous research results. These residual materials have to be measured, described and declared in order to safely reuse these materials or to dispose them in a controlled way. This is a challenge for the radioactive waste management group. The application areas at the research facility are divided in groups with similar radioactive inventory: - The ion sources with depleted uranium; - The beam line an the surrounding areas with mainly activation nuclides; - The caves for the experiments with activation products as well as contaminations from target material or open sources in rare occasions; - the radiochemical laboratories where all nuclides especially transuranium targets are handled. These nuclides are partially difficult to detect. One of the problems for radioactive waste management is the determination of nuclides and their activities. Another one is the chemical composition of the waste material. Materials with different properties must be strictly separated and described. In this paper the specific problems for all 4 groups are discussed and the characteristic solutions presented. In the future with the new facility FAIR higher beam energies and intensities will require an efficient radioactive waste management for optimised waste reduction and effective handling methods. (orig.)

  20. Cosmogenic nuclides principles, concepts and applications in the earth surface sciences

    Dunai, Tibor J

    2010-01-01

    This is the first book to provide a comprehensive and state-of-the-art introduction to the novel and fast-evolving topic of in-situ produced cosmogenic nuclides. It presents an accessible introduction to the theoretical foundations, with explanations of relevant concepts starting at a basic level and building in sophistication. It incorporates, and draws on, methodological discussions and advances achieved within the international CRONUS (Cosmic-Ray Produced Nuclide Systematics) networks. Practical aspects such as sampling, analytical methods and data-interpretation are discussed in detail and an essential sampling checklist is provided. The full range of cosmogenic isotopes is covered and a wide spectrum of in-situ applications are described and illustrated with specific and generic examples of exposure dating, burial dating, erosion and uplift rates and process model verification. Graduate students and experienced practitioners will find this book a vital source of information on the background concepts and...

  1. Transmutation calculations for the accelerator transmutation of waste (ATW) program

    The disposal of radioactive waste by the transmutation of long-lived radionuclides is being considered; now using neutrons produced with an intense beam of 1.6-GeV protons on a Pb-Bi target. Study teams have been active in the areas of accelerator design, beam transport, radiation transport, transmutation, fluid flow and heat transfer, process chemistry and system analyses. Work is of a preliminary and developmental nature. Here we describe these preliminary efforts in transmutation calculations; the tools developed, status of basic nuclear data, and some early results. These calculations require the description of the intensity and spectrum of neutrons produced by the beam, the distribution of nuclides produced in the medium-energy reactions, the transport of particles produced by the beam, the transmutation of the target materials and transmutation products, and the decay properties of the inventory of radionuclides produced

  2. ORIGEN-JR, Radiation Source and Nuclide Transmutation with In-Core Burnup

    1 - Description of problem or function: ORIGIN-JR, which has been developed from ORIGEN, calculates radiation sources and analyses nuclide transmutations. The calculation of neutron source spectra has been revised extensively. In addition to the spectrum indices adopted in ORIGEN, one-group cross sections for each reaction can be used to treat precisely the burnup conditions in a reactor core. Neutron and gamma-ray source data are generated in the same format as in the shielding codes QAD-PS, ANISN and DOT. 2 - Method of solution: The code solves the equations of radioactive nuclide transmutation and calculates radiation sources. Energy spectra of neutron sources in spontaneous fission and (alpha, n) reactions of eight nuclides (9Be, 10B, 11B, 13C, 14N, 17O, 18O and 19F) are available. Complex decay and transmutation schemes and one-group reaction cross sections can be treated. A Matrix Exponential method is used to solve the resultant large system of coupled, linear, first-order, ordinary differential equations with constant coefficients. 3 - Restrictions on the complexity of the problem: The code will handle 850 nuclides of which no more than 500 are described as light elements, no more than 120 are actinides and their decay daughters, and no more than 500 are fission products. Fission products are produced by fission rates of five different actinides. In addition, there may be no more than 3000 non-zero elements in the nuclear transmutation matrix. Numerical inaccuracies due to too coarse a time spacing are indicated by a warning message. Neutron spectra due to (alpha, n) reaction can be calculated by no more than 61 actinides and 8 light nuclides

  3. Enrichment of radioactive nuclides in sewage sludge

    As a consequence of the Chernobyl reactor accident, precipitations in various parts of Europe carried radioactivity for a short period. This meant necessarily that the water received by sewage treatment plants was also polluted. Measurements in a sewage treatment plant having received sewage water which carried radioactivity showed the following: Active nuclides are removed from the sewage water and are to a high extent enriched in sewage sludge. On comparison of the values for the activity of sludges with the stages of the plant, an increase in specific activity (nCi/kg) is found in parallel to the increase in the share of dry substance. Centrifugation of sludges yields a supernatant of relatively low radioactivity, while the radioactive elements are enriched in the sediment. By far the highest activities are found in the ashes of burnt sludge (2860 nCi/kg) and in dewatered sludges. These results are confirmed by comparison measurements in six other plants. In the period between May 7th, 1986 and June 16th, 1986, activities in digester sludge were measured ranging from 395 to 58.6 nCi/l; in pressed sludge, 1717 to 290.4 nCi/l were measured. (orig./RB)

  4. Quantifying Holocene and Anthropocene erosion rates with cosmogenic and fallout nuclides

    Short-lived cosmogenic nuclides, such as in-situ produced 14C in quartz, and fallout nuclides, such as 137Cs and 239,240Pu, are particularly suited to determine Holocene and/or anthropogenic rates of soil erosion. While fallout 137Cs has been widely used to study erosion processes, the methodology and application of the in-situ produced 14C and 239,240Pu are still somewhat experimental. In the case of in-situ 14C it are experimental/methodological obstacles that stand in the way of wider application, in the case of fallout plutonium it is down to neglect. This experimental/neglected status is a pity, since in situ 14C has the potential to allow resolving Holocene from longer-term Earth-surface process rates, whereas fallout Pu can be used to overcome difficulties in 137Cs methodology arising from the Chernobyl fallout (particularly in Europe) and the relative short half-life of radionuclides of Cs. The presentation will (i) introduce the intrinsic methodological benefits of in-situ produced radiocarbon and fallout plutonium, (ii) report on developmental work at CologneAMS to establish routine use of these nuclides and (iii) present a showcase application for fallout plutonium. (author)

  5. Demonstration of fusion-evaporation and direct-interaction nuclear reactions using high-intensity laser-plasma-accelerated ion beams

    Heavy-ion induced nuclear reactions in materials exposed to energetic ions produced from high-intensity (∼5x1019 W/cm2) laser-solid interactions have been experimentally investigated for the first time. Many of the radionuclides produced result from the creation of ''compound nuclei'' with the subsequent evaporation of proton, neutron, and alpha particles. Results are compared with previous measurements with monochromatic ion beams from a conventional accelerator. Measured nuclide yields are used to diagnose the acceleration of ions from laser-ablated plasma to energies greater than 100 MeV

  6. Dosimetry and monitoring of thin X-ray beam produced by linear particle accelerator, for application in radiography

    The dosimetry and monitoring characteristics of thin X-ray beams, and the application of 4MeV linear particle accelerator to radiosurgery are studied. An addition collimation system, consisted of 3 lead collimators, which allows to obtain thin beams of 6,10 and 15 mm of diameter, was fabricated. The stereo taxic system, together with modifications in dispositives, provide the accuracy required in volum-targed location. The dosimetric informations were determined with silicon detector inserted into water simulator. The isodose curves for each beam, and total isodoses simulating the treatment were established using radiographic emulsions in conditions which reproduce real circunstances of pacient irradiation. (M.C.K.)

  7. Determination and declaration of critical nuclide inventories in Belgian NPP radwaste streams

    The nuclear power plants (NPPs) managed by ELECTRABEL are located at the Doel (4 units) and the Tihange (3 units) sites and have a total capacity of 5700 MW(e). All the units are of the PWR type. Taking into account the need for retrievability and reliability of all requested waste data, the operator ELECTRABEL has subcontracted a complete study to the engineering company TRACTEBEL ENERGY ENGINEERING (TEE) in order to elaborate a computer code for the determination of critical nuclides in the different waste streams. This program should guarantee retrievability and reliability of all information related to the waste packages produced at the NPP. Two computer codes, LLWAA and DECL, have therefore been developed by TEE. The first code (LLWAA: low level waste activity assessment code), enables to predict the global inventories and/or the scaling factors of the critical nuclides in the conditioned and in the non-conditioned waste generated by the operation of a PWR. This code is site-specific as it takes into account the plant design characteristics and operating conditions. A version for BWR plants is under development. The second code 'DECL', deals mainly with the complete database management of each waste package produced in order to guarantee full retrievability. LLWAA and DECL are implemented as an integrated software package called 'DECLARE' at the sites of Doel and Tihange. Furthermore, the LLWAA-code has been extended for the determination of the critical nuclides activities in ashes produced by incineration (LLWAA-Ashes) and for the assessment of the critical nuclides activities deposited on equipment of the nuclear auxiliary systems (LLWAA-Decom). (author)

  8. Investigation of radiopharmaceuticals from cyclotron produced radionuclides and development of mathematical models. Part of a coordinated programme on production of radiopharmaceuticals from accelerator-produced isotopes

    Several radioisotopes for diagnostic uses in nuclear medicine studies are produced using the internal 15 MeV (30 MeV alphas) deuteron beam of the ''Ruder Boskovic'' Institute in Zagreb, Yugoslavia. Some of the most important radioisotopes produced during the last few years are: Gallium-67 (d, xn reaction on a Cu/Ni/Zn target) with yield of 7.6 MBq/uAh, 81Rb-sup(81m)Kr generator (α, 2n reaction on a Cu/Cu2Br2 target) with a yield of 99 MBq/uAh, Iodine-123 (α, 2n reaction on a Cu/Ag/Sb target) with a yield of 6.3 MBq/uAh, and Indium-111 (α, 2n reaction on a Cu/Cu/Ag target) with a yield of 7.2 MBq/uAh. In addition, a simple mathematical lung model for regional ventilation measurements was developed and used for ventilation studies on normal subjects and subjects with various lung diseases. Based on these studies, a more sophisticated and quantitative lung ventilation model for radioactive tracer tidal breathing was further developed. In this new model, the periodicity of breathing is completely taken into account, and it makes possible to actually determine lung ventilation and volume parameters. The model is experimentally verified on healthy subjects, and the value of the effective specific ventilation obtained is in agreement with comparable parameters in the literature. sup(81m)Kr from a generator was used to perform these experimental studies

  9. Accelerated methanogenesis from effluents of hydrogen-producing stage in anaerobic digestion by mixed cultures enriched with acetate and nano-sized magnetite particles.

    Yang, Zhiman; Xu, Xiaohui; Guo, Rongbo; Fan, Xiaolei; Zhao, Xiaoxian

    2015-08-01

    Potential for paddy soil enrichments obtained in the presence of nano-sized magnetite particles (named as PSEM) to promote methane production from effluents of hydrogen-producing stage in two-stage anaerobic digestion was investigated. The results showed that the addition of magnetite significantly accelerated methane production from acetate in a dose-independent manner. The results from high-throughput sequencing analysis revealed that Rhodocyclaceae-related species were selectively enriched, which were likely the key players for conversion of acetate to methane in PSEM. Compared to the paddy soil enrichments obtained in the absence of magnetite (named as PSEC), the maximum methane production rate in PSEM was significantly higher (1.5-5.5times higher for the artificial medium and 0.2-1.7times higher for the effluents). The accelerated methane production from the effluents indicated remarkably application potential of PSEM for improving performance of anaerobic digestion. PMID:25935393

  10. A computer code for calculation of radioactive nuclide generation and depletion, decay heat and γ ray spectrum. FPGS90

    In a nuclear reactor radioactive nuclides are generated and depleted with burning up of nuclear fuel. The radioactive nuclides, emitting γ ray and β ray, play role of radioactive source of decay heat in a reactor and radiation exposure. In safety evaluation of nuclear reactor and nuclear fuel cycle, it is needed to estimate the number of nuclides generated in nuclear fuel under various burn-up condition of many kinds of nuclear fuel used in a nuclear reactor. FPGS90 is a code calculating the number of nuclides, decay heat and spectrum of emitted γ ray from fission products produced in a nuclear fuel under the various kinds of burn-up condition. The nuclear data library used in FPGS90 code is the library 'JNDC Nuclear Data Library of Fission Products - second version -', which is compiled by working group of Japanese Nuclear Data Committee for evaluating decay heat in a reactor. The code has a function of processing a so-called evaluated nuclear data file such as ENDF/B, JENDL, ENSDF and so on. It also has a function of making figures of calculated results. Using FPGS90 code it is possible to do all works from making library, calculating nuclide generation and decay heat through making figures of the calculated results. (author)

  11. Catalogue of gamma rays from radionuclides ordered by nuclide

    A catalogue of about 28500 gamma-ray energies from 2338 radionuclides is presented. The nuclides are listed in order of increasing (A,Z) of the daughter nuclide. In addition the gamma-ray intensity per 100 decays of the parent (if known) and the decay half-life are given. All data are from a computer processing of a recent ENSDF (Evaluated Nuclear Structure Data File) file. (authors)

  12. [The fate of nuclides in natural water systems

    Our research at Yale on the fate of nuclides in natural water systems has three components to it: the study of the atmospheric precipitation of radionuclides and other chemical species; the study of the behavior of natural radionuclides in groundwater and hydrothermal systems; and understanding the controls on the distribution of radionuclides and stable nuclides in the marine realm. In this section a review of our progress in each of these areas is presented

  13. Librarian driven analysis with graphic user interface for nuclides quantification by gamma spectra

    For a set of a priori given radionuclides extracted from a general nuclide data library, the authors use median estimates of the gamma-peak areas and estimates to produce a list of possible radionuclides matching gamma-ray line(s). An a priori determined list of nuclides is obtained by searching for a match with the energy information of the database. This procedure is performed in an interactive graphic mode by markers that superimpose, on the spectral data, the energy information and yields provided by a general gamma-ray data library. This library of experimental data includes approximately 17,000 gamma-energy lines related to 756 known gamma emitter radionuclides listed by ICRP

  14. Development of a postal system for dosimetry quality control performed in photon beams produced by linear accelerators of clinical use

    In this work a different system is proposed which is able to verify the absorbed depth dose given at two different depths, the irradiation field homogeneity and its coincidence with the light field of the machine, the source to surface distance used and the beam nominal energy. These radiation field parameters are very important in the tumour treatment and they may help in the determination of the error sources of the absorbed depth dose. The system developed uses a water phantom, LiF thermoluminescent dosemeters and a radiographic film to evaluate such parameters. The postal system developed in this work has been tested in linear accelerators of 4 to 18 MV with good results. (author)

  15. Polychromatic X-ray Beam from the Acceleration of Energetic Electrons in Ultrafast Laser-Produced Plasmas

    Albert, Félicie; Taphuoc, Kim; Shah, Rahul; Burgy, Frederic; Rousseau, Jean Philippe; Rousse, Antoine

    2007-01-01

    Polychromatic beams of hard X-rays from ultrafast laser plasma interaction are studied. Just as in a conventional synchrotron, electrons are accelerated and wiggled, but on a much shorter scale of a few millimeters. By focusing a 50 TW CPA laser system (30 fs duration) onto a helium gas jet, we obtained a polychromatic collimated beam (50 mrad) of X-ray radiation in the keV range. In addition, its perfect synchronization with the laser system, its ultrafast duration (≃30 fs) and its brightness (up to 108 photons/shot/solid angle at 0.1% BW) will make it applicable to both X-ray science and backlighting to address laboratory astrophysics research issues.

  16. Mass measurements on short-lived Cd and Ag nuclides at the online mass spectrometer ISOLTRAP

    Breitenfeldt, Martin

    2009-07-03

    the rp process that will enable a more reliable determination of the composition of the produced material at A = 99. It has been shown that the mass of {sup 99}Cd strongly affects the A = 99 production in an X-ray burst model, and that uncertainties have been significantly reduced from more than an order of magnitude to about a factor of 3. The dominant source of uncertainty is now the mass of {sup 100}In. In principle, other uncertainties will also contribute. These include those of masses of lighter Cd isotopes, where similar rp-process branchpoints occur and which might affect feeding into the {sup 99}Cd branchpoint. In addition, nuclear reaction rate uncertainties will also play a role. However, as reaction rates affect branchings in a linear fashion, while mass differences enter exponentially, mass uncertainties will tend to dominate [Sch06]. Also, which reaction rates are important depends largely on nuclear masses. For example, for low S{sub p}({sup 100}In) a (p,{gamma})-({gamma},p) equilibrium will be established between {sup 99}Cd and {sup 100}In and the {sup 100}In(p,{gamma}) reaction rate would affect the A = 99 production, while for larger S{sub p}({sup 100}In) the {sup 99}Cd(p,{gamma}) reaction rate might be more relevant. Therefore, the mass uncertainties should be addressed first. Once they are under control, further improvements might be possible by constraining proton capture rates. The presented results are relevant for any rp-process scenario with a reaction flow through the {sup 99}Cd region. Here, an X-ray burst model has been used to investigate in detail the impact of the present measurements on such an rp process. The {nu}p process in core collapse supernovae might be another possible scenario for an rp process in the {sup 99}Cd region. It it is planed to also explore whether in that case mass uncertainties have a similar impact on the final composition. On the neutron-rich side of the valley of stability for the Cd and Ag chains of nuclides

  17. Accelerator waste, what to do?

    Full text: The problem of radioactive waste and its management is realised by the public mostly in connection with the controversies surrounding nuclear energy. In this context the waste generated by medicine, industry and research is very often overlooked. In practice the waste management community does not realise the problem of radioactive materials generated in accelerator facilities. This waste is part of the waste from medicine, industry and research. Only a few contributions at international meetings have discussed the theme of accelerator waste, and these few were focused on radiation protection problems rather than on waste management. Beside nuclear and non nuclear related energy research at the Paul Scherrer Institute in Villigen/Switzerland a proton accelerator complex has been in operation since 1964. In the PSI facility hydrogen is ionised and the resulting protons are accelerated to 72 MeV for injection into a ring cyclotron were they are accelerated to 590 MeV. They are then used for many different physical and medical purposes. The beam current has increased from some μA. in the beginning to 2 mA today. Primary beam protons hit the targets and beam dumps where they cause nuclear reactions, including spallation, which produces secondary protons and neutrons and lighter nuclei. The secondary radiation activates construction and shielding material. - Copper, carbon and lead are typical target and beam dump materials, while steel, cast iron and aluminium are used for construction along with copper and PVC in electrical wiring. Normal and heavy concrete arc used as shielding materials. During the long activation period a nuclide inventory is built up not only from the primary materials but also from additives and impurities. High activities are produced in the relatively small volumes of targets and beam dumps. In comparison the large volumes of the construction and shielding materials result in activated materials with low specific activity. The

  18. 600 MeV Simulation of the Production of Cosmogenic Nuclides in Meteorites by Galactic Protons

    2002-01-01

    A large variety of stable and radioactive nuclides is produced by the interaction of solar and galactic cosmic rays with extraterrestrial matter. Measurements of such cosmogenic nuclides provide information about the constancy of cosmic ray fluxes in space and time and about the irradiation history of individual extraterrestrial objects provided that there exist reliable models describing the production process. For the calculation of the depth dependent production of cosmogenic nuclides in meteorites no satisfactory Therefore, the irradiation of small stony meteorites (radii~$<$~40~cm) by galactic protons is simulated in a series of thick target irradiation experiments at the 600~MeV proton beam of the SC. \\\\ \\\\ The thick targets are spheres (R = 5, 15, 25 cm) and are made out of diorite because of its low water content, its high density (3.0~g/cm|3) and because it provides a good approximation of the chemical composition of some common meteorite clas These spheres will also contain a wide variety of pure...

  19. Exposure to 56Fe irradiation accelerates normal brain aging and produces deficits in spatial learning and memory

    Shukitt-Hale, Barbara; Casadesus, Gemma; Carey, Amanda N.; Rabin, Bernard M.; Joseph, James A.

    Previous studies have shown that radiation exposure, particularly to particles of high energy and charge (HZE particles) such as 56Fe, produces deficits in spatial learning and memory. These adverse behavioral effects are similar to those seen in aged animals. It is possible that these shared effects may be produced by the same mechanism. For example, an increased release of reactive oxygen species, and the subsequent oxidative stress and inflammatory damage caused to the central nervous system, is likely responsible for the deficits seen in aging and following irradiation. Therefore, dietary antioxidants, such as those found in fruits and vegetables, could be used as countermeasures to prevent the behavioral changes seen in these conditions. Both aged and irradiated rats display cognitive impairment in tests of spatial learning and memory such as the Morris water maze and the radial arm maze. These rats have decrements in the ability to build spatial representations of the environment, and they utilize non-spatial strategies to solve tasks. Furthermore, they show a lack of spatial preference, due to a decline in the ability to process or retain place (position of a goal with reference to a “map” provided by the configuration of numerous cues in the environment) information. These declines in spatial memory occur in measures dependent on both reference and working memory, and in the flexibility to reset mental images. These results show that irradiation with 56Fe high-energy particles produces age-like decrements in cognitive behavior that may impair the ability of astronauts, particularly middle-aged ones, to perform critical tasks during long-term space travel beyond the magnetosphere.

  20. Radiochemical studies of some low and medium energy nuclear reactions produced by accelerated tritons, deuterons, and protons

    Excitation functions have been measured for the production of 196Au, 196/sup m/Au, 198/sup g/Au, 198/sup m/Au, 199Au, 195/sup g/ Hg, 195/sup m/Hg, 197/sup g/Hg, 197/sup m/Hg and 199/sup m/Hg by 6- to 24-MeV deuteron and triton bombardments of stable 197Au. The radioactive products were determined by measurement of their characteristic gamma-rays on a Ge(Li) detector-pulse height analyzer system. The experimental results have been compared with results of compound-nucleus calculations incorporating pre-equilibrium particle emission. E3 isomeric states of 93Y and 101Ag have been discovered. These activities were produced by short bursts of beam on isotopically enriched targets; the decay γ-rays were measured with a Ge(Li) detector-PHA system operated by a computer arrangement. Hindrance factors for the E3 transitions were calculated and discussed. Chemical procedures have been developed for the isolation of spallation-produced radio-yttrium and radiopotassium from molybdenum and vanadium targets, respectively. These procedures incorporate precipitation, solvent extractions, and ion exchange techniques. The interaction of 800-MeV protons with a thin vanadium target was studied, and cross sections for the formation of 42K and 43K were measured. (U.S.)

  1. Accelerated dysbiosis of gut microbiota during aggravation of DSS-induced colitis by a butyrate-producing bacterium.

    Zhang, Qianpeng; Wu, Yanqiu; Wang, Jing; Wu, Guojun; Long, Wenmin; Xue, Zhengsheng; Wang, Linghua; Zhang, Xiaojun; Pang, Xiaoyan; Zhao, Yufeng; Zhao, Liping; Zhang, Chenhong

    2016-01-01

    Butyrate-producing bacteria (BPB) are potential probiotic candidates for inflammatory bowel diseases as they are often depleted in the diseased gut microbiota. However, here we found that augmentation of a human-derived butyrate-producing strain, Anaerostipes hadrus BPB5, significantly aggravated colitis in dextran sulphate sodium (DSS)-treated mice while exerted no detrimental effect in healthy mice. We explored how the interaction between BPB5 and gut microbiota may contribute to this differential impact on the hosts. Butyrate production and severity of colitis were assessed in both healthy and DSS-treated mice, and gut microbiota structural changes were analysed using high-throughput sequencing. BPB5-inoculated healthy mice showed no signs of colitis, but increased butyrate content in the gut. In DSS-treated mice, BPB5 augmentation did not increase butyrate content, but induced significantly more severe disease activity index and much higher mortality. BPB5 didn't induce significant changes of gut microbiota in healthy hosts, but expedited the structural shifts 3 days earlier toward the disease phase in BPB5-augmented than DSS-treated animals. The differential response of gut microbiota in healthy and DSS-treated mice to the same potentially beneficial bacterium with drastically different health consequences suggest that animals with dysbiotic gut microbiota should also be employed for the safety assessment of probiotic candidates. PMID:27264309

  2. An application of Accelerator Mass Spectrometry to geology

    The radionuclide 10Be is produced in the atmosphere by fragmentation reactions induced by the impact of high energy cosmic protons on N2 and O2 molecules. It arrives to the oceans through wet precipitation and it is then accumulated in deep sea sediments. Therefore, the presence of 10Be in volcanic rocks provides clear evidence that the sediments are being incorporated beneath arcs during the subduction process of the tectonics plates, since the half life of 10Be is too short (1.39 My r,) to be present in the mantle. Accelerator Mass Spectrometry (A MS) is the most sensitive technique for the detection of long lived radioisotopes (or even stable nuclides), being capable of detecting one radioactive atom among 1015 of its stable isotope. The improvement of A MS over the conventional Mass Spectrometry (MS) relies on the use of the tandem accelerator, which ensures the destruction of isobar molecules at the stripper and provides high energy for the discrimination of isobar nuclides. With the purpose of estimate the amount of sediments involved in the subduction process a simply d model was used and the isotopic ratio 10Be/9Be have been measured by A MS in ash samples of three different volcanoes of South America. The measurements were performed in a 3 MV accelerator at VERA (Vienna Environ mental Research Accelerator) by using a 500 nm silicon nitride foil like passive absorber together with a switching magnet in order to reduce the isobaric interference of 10B. Besides, an ionization chamber with segmented anode at the end of the line allowed the discrimination of other interfering particles. The ratios found (10Be/9Be∼ 10-10) are one order of magnitude higher than the reported values in volcanic rocks. It could be due to atmospheric contamination of the samples with 10Be during the eruption. New measurements with samples leached with weak acids are planed to carried out using the TANDAR accelerator

  3. Size effect in nuclide leachability of plastic solidified bodies

    In medium to low level radioactive solid wastes from nuclear power plants, the experiment on nuclide leachability has been usually made by solid size of about 100 cm3. The results are taken as the nuclide leachability for the solids of actual size (about 200 liters). It has been studied how the leachability of nuclides varies with the size of solids. Therefore, diffusion coefficient was measured for the plastic solids of different sizes from 5 cm3 to 235 cm3 in order to examine the size effect. In the range of size measured, the effect of solid size upon the diffusion coefficient was little observed; the values were about 10-5 cm2/day in all cases. The thermosetting resin used for plastic solidification was unsaturated polyester plus sodium sulfate (40/60). About 0.2 μCi of 137Cs per 10 g of solid was contained in each plastic solid. (Mori, K.)

  4. Predictions of the mass surface near the doubly magic nuclide

    Predictions of the mass surface of nuclei close to the doubly magic nuclide 78Ni are performed in this work. For this purpose two methods for determination of mass values near the doubly closed shell nuclide have been used. The first involves calculations within the framework of multiparticle shell model based on the proper average field potential and effective forces. The second one is based on the concept of magic crosses, which allows to obtain the mass values of odd-odd nuclei near 78Ni by using the similarities in practical orbit sequences and the equality of the proton-neutron interaction energies for some two-quasiparticle multiplets in the vicinities of similar known heavy magic nuclides. The value of the neutron and two-neutron separation energies as well as the β-decay energies of astrophysical interest near 78Ni are presented

  5. Variable temperature effects on release rates of readily soluble nuclides

    In this paper we study the effect of temperature on the release rate of readily soluble nuclides, as affected by a time-temperature dependent diffusion coefficient. In this analysis ground water fills the voids in the waste package at t = 0 and one percent of the inventories of cesium and iodine are immediately dissolved into the void water. Mass transfer resistance of partly failed container and cladding is conservatively neglected. The nuclides move through the void space into the surrounding rock under a concentration gradient. We use an analytic solution to compute the nuclide concentration in the gap or void, and the mass flux rate into the porous rock. 8 refs., 4 figs

  6. Feasibility of fuel cycle characterization using multiple nuclide signatures

    The feasibility of identifying spent nuclear fuel arising from an unknown fuel cycle in terms of reactor type and burnup using a database of nuclide composition vectors generated for combinations of these two variables is examined. The database and test cases were generated using ORIGEN-ARP, and the concentrations of 200 nuclides were analyzed for each sample. Nearest neighbors and ridge regression techniques were used to make predictions of the reactor type and burnup of test cases. Various truncated nuclide lists were also tested. An initial examination of the techniques' sensitivity to measurement error was made by perturbing the unknowns' composition vector and examining the effect on each of the technique's predictions. We demonstrate through the results of these experiments that investigation and development of multivariate data analysis methodologies for nuclear forensics applications is warranted. (author)

  7. Cross Sections for the Production of Residual Nuclides by Proton-Induced Reactions with Uranium at Medium Energies

    The production of residual nuclides by proton-induced reactions on uranium is investigated using activated targets from irradiation experiments at Saturne II synchrocyclotron at the Laboratory National Saturne/Saclay. These investigations contribute to the European research project NUDATRA within the IP EUROTRANS in which the feasibility of accelerator-driven transmutation of nuclear waste is evaluated. Experimental cross sections are derived from gamma-spectrometric measurements. A total of 1894 cross-section was deter-mined covering 44 residual nuclides in the energy range from 211 MeV to 2530 MeV. The experimental data together with those of earlier work of our group are discussed in the context of theoretical excitation functions calculated by the newly developed INCL4 + ABLA and the TALYS codes

  8. Calculation of dose equivalent index, effective dose equivalent and ambient dose equivalent for the giant resonance neutron spectra produced at an electron accelerator

    The ANISN code has been used in this study to evaluate the attenuation of neutron beams of various spectra incident normally on slabs of different kinds of concrete. Spectra of the most common sources (Am-Be and Cf-252) and those of giant resonance neutrons, produced at electron accelerators, were studied. The concretes examined had densities between 2.1 and 4.64 g.cm-3. The calculation were made in terms of the deep dose equivalent index, the effective dose equivalent and the ambient dose equivalent. Values of attenuation length in the various materials were derived from the attenuation curves. The results found should allow for useful evaluations in every day practice for health physicist

  9. Calculated neutron-activation cross sections for E/sub n/ /le/ 100 MeV for a range of accelerator materials

    Activation problems associated with particle accelerators are commonly dominated by reactions of secondary neutrons produced in reactions of beam particles with accelerator or beam stop materials. Measured values of neutron-activation cross sections above a few MeV are sparse. Calculations with the GNASH code have been made for neutrons incident on all stable nuclides of a range of elements common to accelerator materials. These elements include B, C, N, O, Ne, Mg, Al, Si, P, S, Ar, K, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, Nd, and Sm. Calculations were made for a grid of incident neutron energies extending to 100 MeV. Cross sections leading to the direct production of as many as 87 activation products for each of 84 target nuclide were tabulated on this grid of neutron energies, each beginning with the threshold for the product nuclide's formation. Multigrouped values of these cross sections have been calculated and are being integrated into the cross-section library of the REAC-2 neutron activation code. Illustrative cross sections are presented. 20 refs., 6 figs., 1 tab

  10. Studies of heavy radioactive nuclides transmutation using relativistic particles at the JINR (Dubna)

    We overview briefly the investigations of the process of transmutation of long-lived fission products into short-lived or stable nuclides, which are conducted for several years at the synchrophasotron of the Joint Institute for Nuclear Research (JINR), Dubna, using the beams of protons and 12C ions of 3.67 GeV and 18 GeV energy, respectively. As a result of these experiments it has been found that the measured transmutation rates for these nuclides irradiated with the help of rather simple and versatile experimental arrangement allows to estimate the transmutation rate capacity for a 10 m A -1.5 GeV proton accelerator coupled to a Pb target as: 4% of 129I into 130Xe for one year and 6% of 237Np into 238Np during one month. Current methodical and computational problems arising in the relevant works are also discussed. Some remarks concerning similar investigations conducted in other laboratories (in particular, at CERN [3]) are made, too

  11. Low energy, photon emitting nuclides: reference spectra library

    This section presents a reference library consisting of the measured spectral response of the NaI(Tl)-CsI(Tl) detector to individual low energy photon-emitting nuclides in a point source geometry. The reference spectra collection will be limited to radionuclides which emit photons in the energy range below 20 keV

  12. U-Th series nuclides in the Gulf of Mexico

    A study of U and Th series nuclides is being conducted on sediments from the Gulf of Mexico. Uranium concentrations as a function of depth have been determined, as well as changes in the 234U/238U activity ratio. The geochemical behavior of uranium in shelf sediments is discussed

  13. Evaluation of Nuclide Release Scenarios for a Hypothetical LILW Repository

    A program for the safety assessment and performance evaluation of a low- and intermediate-level radioactive waste (LILW) repository system has been developed. Utilizing GoldSim (GoldSim, 2006), the program evaluates nuclide release and transport into the geosphere and biosphere under various disruptive natural and manmade events and scenarios that can occur after a waste package failure. We envisaged and illustrated these events and scenarios as occurring after the closure of a hypothetical LILW repository, and they included the degradation of various manmade barriers, pumping well drilling, and natural disruptions such as the sudden formation of a preferential flow pathway in the far-field area of the repository. Possible enhancement of nuclide transport facilitated by colloids or chelating agents is also dealt with. We used the newly-developed GoldSim template program, which is capable of various nuclide release scenarios and is greatly suited for simulating a potential repository given the geological circumstances in Korea, to create the detailed source term and near-field release scheme, various nuclide transport modes in the far-field geosphere area, and the biosphere transfer. Even though all parameter values applied to the hypothetical repository were assumed, the illustrative results, particularly the probabilistic calculations and sensitivity studies, may be informative under various scenarios

  14. Quantifying nuclide contributions to reactor behaviour over time

    Christie, S.A.

    2014-01-01

    This thesis describes the application of adjoint techniques to fuel cycle analysis, in order to provide a more accurate description of the effects of nuclides on reactor behaviour. Transmutation and decay processes change the composition of the fuel. Allowing for these changes makes it possible to c

  15. Oxidative dissolution of spent fuel and release of nuclides from a copper/iron canister. Model developments and applications

    Three models have been developed and applied in the performance assessment of a final repository. They are based on accepted theories and experimental results for known and possible mechanisms that may dominate in the oxidative dissolution of spent fuel and the release of nuclides from a canister. Assuming that the canister is breached at an early stage after disposal, the three models describe three sub-systems in the near field of the repository, in which the governing processes and mechanisms are quite different. In the model for the oxidative dissolution of the fuel matrix, a set of kinetic descriptions is provided that describes the oxidative dissolution of the fuel matrix and the release of the embedded nuclides. In particular, the effect of autocatalytic reduction of hexavalent uranium by dissolved H2, using UO2 (s) on the fuel pellets as a catalyst, is taken into account. The simulation results suggest that most of the radiolytic oxidants will be consumed by the oxidation of the fuel matrix, and that much less will be depleted by dissolved ferrous iron. Most of the radiolytically produced hexavalent uranium will be reduced by the autocatalytic reaction with H2 on the fuel surface. It will reprecipitate as UO2 (s) on the fuel surface, and thus very little net oxidation of the fuel will take place. In the reactive transport model, the interactions of multiple processes within a defective canister are described, in which numerous redox reactions take place as multiple species diffuse. The effect of corrosion of the cast iron insert of the canister and the reduction of dissolved hexavalent uranium by ferrous iron sorbed onto iron corrosion products and by dissolved H2 are particularly included. Scoping calculations suggest that corrosion of the iron insert will occur primarily under anaerobic conditions. The escaping oxidants from the fuel rods will migrate toward the iron insert. Much of these oxidants will, however, be consumed by ferrous iron that comes from

  16. Measurement of soluble nuclide dissolution rates from spent fuel

    Gaining a better understanding of the potential release behavior of water-soluble radionuclides is the focus of new laboratory spent fuel dissolution studies being planned in support of the Yucca Mountain Project. Previous studies have suggested that maximum release rates for actinide nuclides, which account for most of the long-term radioactivity in spent fuel, should be solubility-limited and should not depend on the characteristics or durability of the spent fuel waste form. Maximum actinide concentrations should be sufficiently low to meet the NRC (Nuclear Regulatory Commission) annual release limits. Potential release rates for soluble nuclides such as 99Tc, 135Cs, 14C and 129I, which account for about 1-2% of the activity in spent fuel at 1,000 years, are less certain and may depend on processes such as oxidation of the fuel in the repository air environment. Dissolution rates for several soluble nuclides have been measured from spent fuel specimens using static and semi-static methods. However, such tests do not provide a direct measurement of fuel matrix dissolution rates that may ultimately control soluble-nuclide release rates. Flow-through tests are being developed as a potential supplemental method for determining the matrix component of soluble-nuclide dissolution. Advantages and disadvantages of both semi-static and flow-through methods are discussed. Tests with fuel specimens representing a range of potential fuel states that may occur in the repository, including oxidized fuel, are proposed. Preliminary results from flow-through tests with unirradiated UO2 suggesting that matrix dissolution rates are very sensitive to water composition are also presented

  17. Important fission product nuclides identification method for simplified burnup chain construction

    A method of identifying important fission product (FP) nuclides which are included in a simplified burnup chain is proposed. This method utilizes adjoint nuclide number densities and contribution functions which quantify the importance of nuclide number densities to the target nuclear characteristics: number densities of specific nuclides after burnup. Numerical tests with light water reactor (LWR) fuel pin-cell problems reveal that this method successfully identifies important FP nuclides included in a simplified burnup chain, with which number densities of target nuclides after burnup are well reproduced. A simplified burnup chain consisting of 138 FP nuclides is constructed using this method, and its good performance for predictions of number densities of target nuclides and reactivity is demonstrated against LWR pin-cell problems and multi-cell problem including gadolinium-bearing fuel rod. (author)

  18. Shielding and activity estimator for template-based nuclide identification methods

    Nelson, Karl Einar

    2013-04-09

    According to one embodiment, a method for estimating an activity of one or more radio-nuclides includes receiving one or more templates, the one or more templates corresponding to one or more radio-nuclides which contribute to a probable solution, receiving one or more weighting factors, each weighting factor representing a contribution of one radio-nuclide to the probable solution, computing an effective areal density for each of the one more radio-nuclides, computing an effective atomic number (Z) for each of the one more radio-nuclides, computing an effective metric for each of the one or more radio-nuclides, and computing an estimated activity for each of the one or more radio-nuclides. In other embodiments, computer program products, systems, and other methods are presented for estimating an activity of one or more radio-nuclides.

  19. Age determination of meteorites using radioactive nuclides

    Recently, the precise isotope ratios of some refractory elements in meteorites have been reported using inductively coupled plasma mass spectrometry. The in situ decay of 182Hf (T1/2=9 Myr), which was produced at the latest nucleosynthesis, is recognized in many meteorites as isotopic anomalies of its daughter isotope, 182W. The degrees of relative 182W isotopic deviation in extra-terrestrial and terrestrial silicate samples vary from +0.3% to ±0% related to the size of their parent bodies. One ready interpretation of its correlation is the difference in timing of metal-silicate separation in the parent bodies. Between the earth and meteorite parent bodies, the difference is calculated to be about four times of the half-life of 182Hf, equivalent to 36 Myr. (author)

  20. Nuclides.net: A computational environment for nuclear data and applications in radioprotection and radioecology

    An interactive multimedia tool, Nuclides.net, has been developed at the Institute for Transuranium Elements. The Nuclides.net 'integrated environment' is a suite of computer programs ranging from a powerful user-friendly interface, which allows the user to navigate the nuclides chart and explore the properties of nuclides, to various computational modules for decay calculations, dosimetry and shielding calculations, etc. The product is particularly suitable for environmental radioprotection and radioecology. (authors)

  1. Vud determination from light nuclide mirror transitions

    Brodeur, M.; Kelly, J.; Long, J.; Nicoloff, C.; Schultz, B.

    2016-06-01

    Thanks to extensive experimental efforts that led to a precise determination of the various superallowed 0+ → 0+ pure Fermi transition experimental quantities, we now have a very precise value for Vud that leads to a stringent test of the CKM matrix unitarity. Despite this achievement, measurements in other less precise systems remain relevant as conflicting results could uncover unknown systematic effects or even new physics. One such system is the superallowed mixed transition, which can help refine the same theoretical corrections used for pure Fermi transitions and hence improve the accuracy of Vud . However, as a corrected Ft -value determination from these systems requires the more challenging determination of the Fermi Gamow-Teller mixing ratio, only five transitions, spreading from 19Ne to 37K, are currently fully characterized. There are several ongoing efforts to determine the mixing ratios for medium-mass nuclei. Measuring transitions in lighter nuclei, such as 17F, 15O, 13N and 11C, poses new challenges as their longer half-lives, ranging from 1 to 22 min, conflict with the time constraints present at the large radioactive ion beam facilities where these nuclei are typically produced. We will present a proposed ion trapping experiment to measure these transitions at the University of Notre Dame where time constraints are less stringent.

  2. Regular Cosmogenic Nuclide Dosing of Sediment Moving Down Desert Piedmonts

    Nichols, K. K.; Bierman, P. R.; Hooke, R. L.; Eppes, M. C.; Persico, L.; Caffee, M.; Finkel, R.

    2001-12-01

    Low-gradient alluvial piedmonts are common in desert areas throughout the world; however, long-term rates of processes that modify these landscapes are poorly understood. Using cosmogenic 10Be and 26Al, we attempt to quantify the long-term (>103 y) behavior of desert piedmonts in Southern California. We measured the activity of 10Be and 26Al in three samples of drainage basin alluvium and six amalgamated samples from transects spaced at 1-km intervals down a piedmont in Fort Irwin, Mojave Desert, California. Each transect sample consists of sediment from 21 collection sites spaced at 150 m intervals. Such sampling averages the variability of nuclide activity between sub-sample locations and thus gives a long-term dosing history of sediment as it is transported from uplands to the distal piedmont. The piedmont is heavily used during military training exercises during which hundreds of wheeled and tracked vehicles traverse the surface. The piedmont surface is planar, and fan-head incision is minimal at the rangefront decreasing to zero between the first and second transects, 1.5 km from the rangefront. 10Be activity increases steadily from 5.87 X 105 atoms g-1 at the rangefront to 1.02 X 6 atoms g-1 at the piedmont bottom. Nuclide activity and distance are well correlated (r2 = 0.95) suggesting that sediment is dosed uniformly as it is transported down piedmont. We have measured similar increases in nuclide activity in transect samples collected from two other Mojave Desert piedmonts, those fringing the Iron and Granite Mountains (Nichols et al, in press, Geomorphology). These piedmonts have nuclide activities that also correlate well with distance (r2 = 0.98 and 0.96, respectively) from their rangefronts, but nuclides increase at a lower rate down piedmont. Modeled sediment transport speeds for the Iron and Granite Mountain piedmonts are decimeters per year. The regular increase in nuclide activities down three different Mojave Desert piedmonts suggests that

  3. An introduction to acceleration mechanisms

    This paper discusses the acceleration of charged particles by electromagnetic fields, i.e., by fields that are produced by the motion of other charged particles driven by some power source. The mechanisms that are discussed include: Ponderamotive Forces, Acceleration, Plasma Beat Wave Acceleration, Inverse Free Electron Laser Acceleration, Inverse Cerenkov Acceleration, Gravity Acceleration, 2D Linac Acceleration and Conventional Iris Loaded Linac Structure Acceleration

  4. The cancerogenicity of fall out nuclides

    One of the more than 400 radionuclides which are produced in a nuclear reactor only a few of these have features such as solubility, long physical and biological half life and specific affinity to a certain tissue - which could classify them as biologically hazardous. Therefore in this context only radio-iodine-cesium and -strontium are discussed briefly as regards their biological effects. It is pointed out that tumours are not easily induced by radioiodine in experimental systems and that this is also valid for humans. Radiocesium is not very extensively studied experimentally as regards its biological action but available data indicate a low - if any - cancerogenic potentiality in contrast to radiostrontium with its high yield of tumours in various tissues. The extrapolation of experimental data to man as well as a comparison between cancerogenic irradiation doses between man and animals are discussed and considered as a necessity because of the ill defined irradiation situation and data which are connected with most accidental exposure of man. Furthermore it is also pointed out that the general idea that irradiation risks always are represented by a linear dose-effect relationship in most cases has no support from scientific data and therefore give an overestimation of the true risk. This should not be considered as a plea for the abandonment of the 'linear philosophy' but it is necessary to point out that as long as other environmental risks are calculated in a more liberal way, irradiation will always be victimized and discriminated against in the large flora of environmental dangers. The necessity of giving a clear reference to the spontaneous incidence of tumours during the time covered by the calculation must also be presented as well as that the estimate is founded on a hypothesis which is not scientifically proven. (author)

  5. Pulsed DC accelerator for laser wakefield accelerator

    For the acceleration of ultra-short, high-brightness electron bunches, a pulsed DC accelerator was constructed. The pulser produced megavolt pulses of 1 ns duration in a vacuum diode. Results are presented from field emission of electrons in the diode. The results indicate that the accelerating gradient in the diode is approximately 1.5 GV/m

  6. Developmentand Application of Accelerator Isotopes in China

    YANG Yuan-you; LI Fei-ze; LIAO Jia-li; Liu, Ning

    2015-01-01

    Compared with the isotopes generated by nuclear reactor, the isotopes prepared by accelerator always show high specific activity and short half-life period. And most of such isotopes always were neutron-deficient nuclides, giving β+ or single energy γ ray. As one of the most important methods preparing radionuclides, the preparation of isotopes by accelerator has attracted more and more attention from the beginning of 21th century. The development of the preparation and application of the acc...

  7. Radio-nuclide mixture identification using medium energy resolution detectors

    Nelson, Karl Einar

    2013-09-17

    According to one embodiment, a method for identifying radio-nuclides includes receiving spectral data, extracting a feature set from the spectral data comparable to a plurality of templates in a template library, and using a branch and bound method to determine a probable template match based on the feature set and templates in the template library. In another embodiment, a device for identifying unknown radio-nuclides includes a processor, a multi-channel analyzer, and a memory operatively coupled to the processor, the memory having computer readable code stored thereon. The computer readable code is configured, when executed by the processor, to receive spectral data, to extract a feature set from the spectral data comparable to a plurality of templates in a template library, and to use a branch and bound method to determine a probable template match based on the feature set and templates in the template library.

  8. Simultaneous evaluation of the nuclear data for heavy nuclides

    Re-evaluation of the nuclear data for 235U, 238U, 239Pu, 240Pu, and 241Pu compiled in the Japanese Evaluated Nuclear Data Library Version 1 (JENDL-1) and evaluation of those for 233U have been performed in the Working Group on Heavy Nuclide Nuclear Data of Japanese Nuclear Data Committee in connection with the preparation of JENDL-2. The re-evaluation is required due to the production of many experimental data on fission cross section since 1975 in which the evaluation work for the JENDL-1 was completed. This re-evaluation work is also needed on account of the imperfection of simultaneous evaluation between the nuclear data of 235U and of the other heavy nuclides in JENDL-1. This paper describes the newly adopted the procedure of simultaneous evaluation, the status of recent fission cross section data measured. (author)

  9. Method of separating useful radioactive nuclide in radioactive liquid waste

    Purpose: To separate useful radioactive nuclides from radioactive liquid wastes for reducing the amount of radioactive secondary wastes generated upon disposal of radioactive liquid wastes. Method: Nitric acid is added to radioactive liquid wastes containing radioactive metal ions, iron ions, nickel ion, chromium ions and oxidative tetravalent serium ions dissolved therein, to convert tetravalent serium ions into complex ions. The liquid wastes are circulated through an ion exchange resin column. This enables to efficiently recover tetravalent serium ions which are useful oxidative nuclides thereby enabling the reuse of serium. Further, since the oxidative nature of the radioactive liquid wastes is eliminated, there is no requirement of adding a reducing agent and it is possible for drying treatment and solidification processing such as plastic solidification. (Takahashi, M.)

  10. Evaluations of heavy nuclide data for JENDL-3.3

    New evaluations of neutron nuclear data for Uranium, Plutonium, and Thorium isotopes which are essential for applications to nuclear technology were carried out for the Japanese Evaluated Nuclear Data Library, JENDL-3.3. The objectives of the current release of JENDL were to fix several problems which have been reported for the previous version, to improve the accuracy of the data, and to evaluate covariances for the important nuclides. Quantities in JENDL-3.2 were extensively re-evaluated or replaced by more reliable values. The heavy nuclide data in JENDL-3.3 were validated with several benchmark tests, and it was reported that the current release gave a good prediction of criticalities. (author)

  11. A GoldSim Model for Colloid Facilitated Nuclide Transport

    Recently several total system performance assessment (TSPA) programs, called 'template' programs, ready for the safety assessment of radioactive waste repository systems which are conceptually modeled have been developed by utilizing GoldSim and AMBER at KAERI. It is generally believed that chelating agents (chelators) that could be disposed of together with radioactive wastes in the repository and natural colloids available in the geological media affect on nuclides by enhancing their transport in the geological media. A simple GoldSim module to evaluate such quantitative effects, by which colloid and chelator-facilitated nuclide release cases could be modeled and evaluated is introduced. Effects of the chelators alone are illustrated with the case associated with well pumping scenario in a hypothetical repository system

  12. Investigation on migration behavior of TRU-nuclides

    The migration behavior of TRU nuclides in geological formation has been studied by a batch and a column method, considering the influence of humic complexation and colloid formation. The migration test of 237Np and 238Pu is carrying out in natural field, to verify the data and the conventional migration model for the safety evaluation of TRU waste disposal. It was found that the migration of 237Np and 238Pu in the natural field is largely retarded sorption onto soil. (author)

  13. Radiometric dating by alpha spectrometry on uranium series nuclides

    Wijk, Albert van der

    1987-01-01

    De Engelse titel van dit proegschrift \\"Radiometric Dating by Alpha Spectometry on Uranium Series Nuclides\\" kan in het Nederlands wellicht het best worden weergegeven door \\"ouderdomsdbepalingen door stralingsmeting aan kernen uit de uraniumreeks met behulp van alfaspectometrie\\". In dit laatste hoofdstuk wil ik proberen om op beknopte, ook voor de niet gespecialiseerde lezer, de inhoud en achtergrond van het onderzoek samen te vatten. Aan het eind van de vorige eeuw werd het verschijnsel ra...

  14. Analytical approach to the evaluation of nuclide transmutations

    Analytical approach to the evaluation of nuclide concentrations in a transmutation chain is presented. Non singular Bateman coefficients and depletion functions are used to overcome numerical difficulties when applying well-known Bateman solution of a simple radioactive decay. Method enables evaluation of complete decay chains without elimination of short lived radionuclides. It is efficient and accurate. Practical application of the method is demonstrated by computing the neptunium series inventory in used Candu TM fuel. (author)

  15. Measurements of neutron cross sections of radioactive waste nuclides

    Katoh, Toshio [Gifu College of Medical Technology, Seki, Gifu (Japan); Harada, Hideo; Nakamura, Shoji; Tanase, Masakazu; Hatsukawa, Yuichi

    1998-01-01

    Accurate nuclear reaction cross sections of radioactive fission products and transuranic elements are required for research on nuclear transmutation methods in nuclear waste management. Important fission products in the nuclear waste management are {sup 137}Cs, {sup 135}Cs, {sup 90}Sr, {sup 99}Tc and {sup 129}I because of their large fission yields and long half-lives. The present authors have measured the neutron capture cross sections and resonance integrals of {sup 137}Cs, {sup 90}Sr and {sup 99}Tc. The purpose of this study is to measure the neutron capture cross sections and resonance integrals of nuclides, {sup 129}I and {sup 135}Cs accurately. Preliminary experiments were performed by using Rikkyo University Reactor and JRR-3 reactor at Japan Atomic Energy Research Institute (JAERI). Then, it was decided to measure the cross section and resonance integral of {sup 135}Cs by using the JRR-3 Reactor because this measurement required a high flux reactor. On the other hand, those of {sup 129}I were measured at the Rikkyo Reactor because the product nuclides, {sup 130}I and {sup 130m}I, have short half-lives and this reactor is suitable for the study of short lived nuclide. In this report, the measurements of the cross section and resonance integral of {sup 135}Cs are described. To obtain reliable values of the cross section and resonance integral of {sup 135}Cs(n, {gamma}){sup 136}Cs reaction, a quadrupole mass spectrometer was used for the mass analysis of nuclide in the sample. A progress report on the cross section of {sup 134}Cs, a neighbour of {sup 135}Cs, is included in this report. A report on {sup 129}I will be presented in the Report on the Joint-Use of Rikkyo University Reactor. (author)

  16. Release of radioactive nuclides from spent WWER fuel

    In this paper, the instant fractional release of gaseous or volatile radionuclides from spent WWER fuel is computationally estimated. A common definition for the instant release is adopted, such that the term refers to the fraction of the inventory of radionuclides that are situated in the fuel-to-cladding gap and may be released instantaneously when the cladding fails for example in a fuel handling accident or during fuel transportation. The analysis is mainly based on the newly amended ANS-5.4 standard by American Nuclear Society’s Standards Committee. Both the nuclides with short half-lives (6 h1/21/2 > 1 y) are considered. The relevant nuclides included to the study are krypton, xenon, iodine, caesium and tellurium. In order to quantify the fractional release of relevant fission products in a fuel handling accident, all the rods of two WWER-440 fuel bundles are simulated with a single rod fuel performance code VTT-ENIGMA. The power histories of the two bundles originate from the design calculations of Loviisa NPP’s reactor core loading, and are chosen so that the first bundle has the highest power, and the second one has the highest burnup. In addition, one more simulation with VTT-ENIGMA is conducted with a power history based on a burnup dependent linear power limit determined for the fuel used in the Loviisa NPP. In order to calculate the release fractions with VTT-ENIGMA, the formulation presented in the ANS-5.4 standard has recently been implemented into the code at VTT. In the analysis, the calculated release fractions of all the studied short-lived nuclides among all the simulated rods are less than 0.11%, and for the long-lived nuclides less than 5%. These results are at or below the level of experimental release fractions found in open literature. (authors)

  17. Hot demonstration of proposed commercial nuclide removal technology

    Lee, D. [Oak Ridge National Lab., TN (United States)

    1996-10-01

    This task covers the development and operation of an experimental test unit located in a Building 4501 hot cell within Building 4501 at Oak Ridge National Laboratory (ORNL). This equipment is designed to test radionuclides removal technologies under continuous operatoin on actual ORNL Melton Valley Storage Tank (MVST) supernatant, Savannah River high-level waste supernatant, and Hanford supernatant. The latter two may be simulated by adding the appropriate chemicals and/or nuclides to the MVST supernatant.

  18. Waste zone labelling at the Lure accelerator facility

    This document describes the method used to compute the activation of the structure components near the electron-positron converter of the Lure accelerator (Orsay). Activation comes from photon and neutron reactions on nuclei belonging to the concrete structure. Only radio-nuclides with a half-life greater than 200 days are considered penalizing for dismantling operations. The main photonuclear reactions produce the following nuclides: Na22, Cl36, Mn54, Nb92, Ba133, Co57 and Co60. The main neutron reaction generate the following nuclides: H3, C14, Cl36, K40, Co60, Ni63, Zn65, Se79, Zr93, Ag108, Ag110, Ba133, Cs134, Eu152, Eu154, Fe55, Ca41, Na22, Mn54, Cs137, Nb92 and Ti204. The MCNPX code has been used to compute the values of the photon and neutron fluxes received by the structure components, the activation has been computed with the Cinder code from the flux values. The main contributors for radioactivity on long term basis appear to be Ca41 and Ni63. Calculations have been compared with the measurement of activities of 3 concrete samples drilled out from the structure. The results of the comparison are given for Co60, Cs134, Eu152 and Eu154. The computed values appear to be greater by a factor varying from 2 to 5 which is consistent with the method used that naturally overestimates the activation. These results are considered as satisfactory for performing waste zone labelling. (A.C.)

  19. Comparison of depletion algorithms for large systems of nuclides

    In this work five algorithms for solving the system of decay and transmutation equations with constant reaction rates encountered in burnup calculations were compared. These are Chebyshev rational approximation method (CRAM), which is a new matrix exponential method, the matrix exponential power series with instant decay and a secular equilibrium approximations for short-lived nuclides, which is used in ORIGEN, and three different variants of transmutation trajectory analysis (TTA), which is also known as the linear chains method. The common feature of these methods is their ability to deal with thousands of nuclides and reactions. Consequently, there is no need to simplify the system of equations and all nuclides can be accounted for explicitly. The methods were compared in single depletion steps using decay and cross-section data taken from the default ORIGEN libraries. Very accurate reference solutions were obtained from a high precision TTA algorithm. The results from CRAM and TTA were found to be very accurate. While ORIGEN was not as accurate, it should still be sufficient for most purposes. All TTA variants are much slower than the other two, which are so fast that their running time should be negligible in most, if not all, applications. The combination of speed and accuracy makes CRAM the clear winner of the comparison.

  20. Measurement of radioactive nuclides in the `Mayak` region

    Myasoedov, B.F. [V.I. Vernadsky Inst. of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Moscow (Russian Federation); Novikov, A.P. [V.I. Vernadsky Inst. of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Moscow (Russian Federation)

    1997-03-01

    The study of environmental contamination caused by anthropogenic impact and, primarily, by radioactive nuclides is one of the main scientific problems facing contemporary science. Radioecological monitoring, decision making on remediation of polluted areas need detailed information about distribution of radioactive nuclides in the terrestrial and aquatic ecosystems, knowledge about radioactive nuclide occurrence forms and migration patterns. Experimental tests of nuclear and thermonuclear weapon in atmosphere and underground, nuclear power engineering and numerous accidents that took place at the nuclear power plants (NPP), unauthorized dump of radioactive materials in various places of the ocean and pouring off the strongly dump of radioactive wastes from ships and submarine equipped with nuclear power engines made artificial radionuclides a constant and unretrievable component of the modern biosphere, becoming an additional unfavorable ecological factor. As regards Former Sovient Union (FSU) the most unfavorable regions are Southern Ural, zones suffered from Chernobyl Accident, Altay, Novaya Zemlya, some part of West Siberia near Seversk (Tomsk-7) and Zheleznogorsk (Krasnoyarsk-26). (orig.)

  1. Recent developments in cosmogenic nuclide production rate scaling

    Lifton, N. A.

    2013-12-01

    A new cosmogenic nuclide production rate scaling model based on analytical fits to Monte Carlo simulations of atmospheric cosmic ray flux spectra (both of which agree well with measured spectra) enables identification and quantification of the biases in previously published models (Lifton, N., Sato, T., Dunai, T., in review, Earth and Planet. Sci. Lett.). Scaling predictions derived from the new model (termed LSD) suggest two potential sources of bias in the previous models: different energy responses of the secondary neutron detectors used in developing the models, and different geomagnetic parameterizations. In addition, the particle flux spectra generated by the LSD model allow one to generate nuclide-specific scaling factors that reflect the influences of the flux energy distribution and the relevant excitation functions (probability of nuclide production in a given nuclear reaction as a function of energy). Resulting scaling factors indicate 3He shows the strongest positive deviation from the flux-based scaling, while 14C exhibits a negative deviation. These results are consistent with previous studies showing an increasing 3He/10Be ratio with altitude in the Himalayas, but with a much lower magnitude for the effect. Furthermore, the new model provides a flexible framework for exploring the implications of future advances in model inputs. For example, the effects of recently updated paleomagnetic models (e.g. Korte et al., 2011, Earth and Planet Sci. Lett. 312, 497-505) on scaling predictions will also be presented.

  2. Transient nuclide release through the bentonite barrier -SKB 91

    A study of near-field radionuclide migration is presented. The study has been performed in the context of the SKB91 study which is a comprehensive performance assessment of disposal of spent fuel. The objective of the present study has been to enable the assessment of which nuclides can be screened out because they decay to insignificant levels already in the near-field of the repository. A numerical model has been used which describes the transient transport of radionuclides through a small hole in a HLW canister imbedded in bentonite clay into a fracture in the rock outside the bentonite. Calculations for more than twenty nuclides, nuclides with both high and low solubility have been made. The effect of sorption in the bentonite backfill is included. The size of the penetration hole was assumed to be constant up to time when the calculations were terminated, 500000 year after the deposition. The mass transport rate is controlled by diffusion. The model is three dimensional. The report describes the geometry of the modelled system, the assumptions concerning the transport resistances at the boundary conditions, the handling of the source term and obtained release curves. (au)

  3. High intensity proton accelerator program

    Industrial applications of proton accelerators to the incineration of the long-lived nuclides contained in the spent fuels have long been investigated. Department of Reactor Engineering of Japan Atomic Energy Research Institute (JAERI) has formulated the Accelerator Program through the investigations on the required performances of the accelerator and its development strategies and also the research plan using the accelerator. Outline of the Program is described in the present report. The target of the Program is the construction of the Engineering Test Accelerators (ETA) of the type of a linear accelerator with the energy 1.5 GeV and the proton current ∼10 mA. It is decided that the construction of the Basic Technology Accelerator (BTA) is necessary as an intermediate step, aiming at obtaining the required technical basis and human resources. The Basic Technology Accelerator with the energy of 10 MeV and with the current of ∼10 mA is composed of the ion source, RFQ and DTL, of which system forms the mock-up of the injector of ETA. Development of the high-β structure which constitutes the main acceleration part of ETA is also scheduled. This report covers the basic parameters of the Basic Technology Accelerator (BTA), development steps of the element and system technologies of the high current accelerators and rough sketch of ETA which can be prospected at present. (J.P.N.)

  4. Radiological safety aspects of the operation of electron linear accelerators

    This manual is intended as a guide for the planning and implementation of radiation protection programmes for all types of electron linear accelerators. Material is provided for guidance in the planning and installation stages, as well as for the implementation of radiation protection for continuing operations. Because of their rapidly growing importance, the problems of installation and radiation safety of standard medical and industrial accelerators are discussed in separate sections. Special discussions are devoted to the radiation protection problems unique to electron accelerators: thick-target bremsstrahlung, the electromagnetic cascade, the estimation of secondary-radiation yields from thick targets, and instrumental corrections for accelerator duty factor. In addition, an extensive review of neutron production is given which includes new calculations of neutron production in various materials. A recalculation of activation in a variety of materials has been done for this manual, and specific gamma-ray constants have been recalculated for a number of nuclides to take into account the contribution of K X-rays. The subjects of air and water activation, as well as toxic gas production in air have been specially reviewed. Betatrons and electron microtrons operating at the same energy produce essentially the same kind of secondary radiation as electron linacs and the material given in this manual is directly applicable to them

  5. DCHAIN: code for analysis of build-up and decay of nuclides

    DCHAIN is a one-point depletion code which solves the coupled equations of radioactive growth and decay for a large number of nuclides by the Bateman method. The present code has the following characteristics: (1) The code can treat any type of transmutation through decays or neutron induced reactions. (2) The code constructs the decay scheme of each nuclide in the code and breaks it up into linear chains. Nuclide names, decay types and branching ratios of mother nuclides are necessary as the input data for each nuclide. Order of nuclides in the library is arbitrary because each nuclide is distinguished by its nuclide name. (3) The code can treat cyclic chains by an approximation. (4) The code performs calculation even if two nuclides with equal decay constants exist in a chain. (5) Cumulative fission yield is used for the top nuclide in each linear chain so that the abundance of each nuclide can be calculated accurately even if the chain length is limited. (6) Power, neutron flux, neutron spectrum, and fission ratio and fission energy of each fissile nuclide can be varied for each time step. (7) Abundances can be calculated for the selected nuclides in the nuclear data library. (8) The code uses variable dimension arrays and there is little limitation in number of nuclides or length of a chain. A library of the nuclear data has been prepared for 1170 fission products, including the data for half-lives and decay schemes, neutron absorption cross sections, fission yields, and disintegration energies. While DCHAIN is used to compute the compositions, radioactivity and decay heat of fission products, the gamma-ray spectrum of fission products can be computed also by a separate code FPGAM using the compositions obtained from DCHAIN. (J.P.N.)

  6. Application of Micro-coprecipitation Method to Alpha Source Preparation for Measuring Alpha Nuclides

    Among the source preparations, an electrodeposition is a commonly used method for the preparation of sources for an alpha spectrometry, because this technique is simple and produces a very thin deposit, which is essential for a high resolution of the alpha peak. Recently, micro-coprecipitation with rare earths have been used to yield sources for -spectrometry. In this work, the Pu, Am and Cm isotopes were purified from hindrance nuclides and elements with an a TRU resin in radioactive waste samples, and the activity concentrations of the Pu, Am and Cm isotopes were determined by radiation counting methods after alpha source preparation like micro coprecipitation. After the Pu isotopes in the radioactive waste samples were separated from the other nuclides with an anion exchange resin, the Am isotopes were purified with a TRU resin and an anion exchange resin or a TRU resin. Activity concentrations and chemical recoveries of 241Am purified with the TRU resin were similar to those with the TRU resin and anion exchange resin. In this study, to save on the analytical time and cost, the Am isotopes were purified with the TRU resin without using an additional anion exchange resin. After comparing the electrodeposition method with the micro-coprecipitation method, the micro-coprecipitation method was used for the alpha source preparation, because the micro-coprecipitation method is simple and more reliable for source preparation of the Pu, Am and Cm isotopes

  7. Isomers in neutron-rich A ∼ 190 nuclides from 208Pb fragmentation

    Relativistic projectile fragmentation of 208Pb has been used to produce isomers in neutron-rich, A ∼ 190 nuclides. A forward-focusing spectrometer provided ion-by-ion mass and charge identification. The detection of gamma-rays emitted by stopped ions has led to the assignment of isomers in 188Ta, 190W, 192Re, 193Re, 195Os, 197Ir, 198Ir, 200Pt, 201Pt, 202Pt and 203Au, with half-lives ranging from approximately 10 ns to 1 ms. Tentative isomer information has been found also for 174Er, 175Er, 185Hf, 191Re, 194Re and 199Ir. In most cases, time-correlated, singles gamma-ray events provided the first spectroscopic data on excited states for each nuclide. In 200Pt and 201Pt, the assignments are supported by gamma-gamma coincidences. Isomeric ratios provide additional information, such as half-life and transition energy constraints in particular cases. The level structures of the platinum isotopes are discussed, and comparisons are made with isomer systematics

  8. Isomers in neutron-rich A∼190 nuclides from 208Pb fragmentation

    Relativistic projectile fragmentation of 208Pb has been used to produce isomers in neutron-rich, A∼190 nuclides. A forward-focusing spectrometer provided ion-by-ion mass and charge identification. The detection of γ-rays emitted by stopped ions has led to the assignment of isomers in 188Ta, 190W, 192Re, 193Re, 195Os, 197Ir, 198Ir, 200Pt, 201Pt, 202Pt and 203Au, with half-lives ranging from approximately 10 ns to 1 ms. Tentative isomer information has been found also for 174Er, 175Er, 185Hf, 191Re, 194Re and 199Ir. In most cases, time-correlated, singles γ-ray events provided the first spectroscopic data on excited states for each nuclide. In 200Pt and 201Pt, the assignments are supported by γ-γ coincidences. Isomeric ratios provide additional information, such as half-life and transition energy constraints in particular cases. The level structures of the platinum isotopes are discussed, and comparisons are made with isomer systematics. (orig.)

  9. Isomers in neutron-rich A{approx}190 nuclides from {sup 208}Pb fragmentation

    Caamano, M.; Podolyak, Z.; Garces Narro, J. [University of Surrey, Department of Physics, Guildford (United Kingdom); Walker, M. [University of Surrey, Department of Physics, Guildford (United Kingdom)]|[TRIUMF, Vancouver (Canada); Regan, P.H. [University of Surrey, Department of Physics, Guildford (United Kingdom)]|[Yale University, Wright Nuclear Structure Laboratory, New Haven (United States); Pfuetzner, M. [Warsaw University, Institute of Experimental Physics, Warsaw (Poland); Gerl, J.; Cortina Gil, D.; Doering, J.; Geissel, H. [GSI, Darmstadt (Germany); Hellstroem, M. [GSI, Darmstadt (Germany)]|[Lund University, Div. of Nuclear Physics (Sweden); Mayet, P. [GSI, Darmstadt (Germany)]|[KU Leuven, IKS, Leuven (Belgium); Mineva, M.N. [Lund University, Division of Nuclear Physics (Sweden); Aprahamian, A. [University of Notre Dame, Department of Physics, South Bend (United States); Benlliure, J. [University of Santiago de Compostela, Departamento de Fisica de Particulas, Santiago de Compostela (Spain); Bruce, A.M. [University of Brighton, School of Engineering, Brighton (United Kingdom); Butler, P.A. [University of Liverpool, Oliver Lodge Laboratory, Liverpool (United Kingdom); Cullen, D.M. [University of Liverpool, Oliver Lodge Laboratory, Liverpool (United Kingdom)]|[University of Manchester, Schuster Lab., Manchester (United Kingdom); Enqvist, T. [GSI, Darmstadt (Germany)]|[Univ. of Jyvaeskylae, Dept. of Physics, Jyvaeskylae (Finland); Fox, C. [Univ. of Liverpool, Oliver Lodge Lab., Liverpool (United Kingdom)]|[Duke Univ., TUNL, Durham (United States); Gelletly, M.; Giovinazzo, J.; Gorska, M.; Grawe, H.; Grzywacz, R.; Kleinboehl, A.H.; Korten, A.; Lewitowicz, M.; Lucas, R.; Mach, H.; O' Leary, C.D.; De Oliveira, F.; Pearson, C.J.; Rejmund, F.; Rejmund, M.; Sawicka, M.; Schaffner, H.; Schlegel, C.; Schmidt, K.; Schmidt, K.H.; Stevenson, P.D.; Theisen, C.; Vives, F.; Warner, D.D.; Wheldon, C.; Wollersheim, S.; Wooding, S.; Xu, F.; Yordanov, O.

    2005-02-01

    Relativistic projectile fragmentation of {sup 208}Pb has been used to produce isomers in neutron-rich, A{approx}190 nuclides. A forward-focusing spectrometer provided ion-by-ion mass and charge identification. The detection of {gamma}-rays emitted by stopped ions has led to the assignment of isomers in {sup 188}Ta, {sup 190}W, {sup 192}Re, {sup 193}Re, {sup 195}Os, {sup 197}Ir, {sup 198}Ir, {sup 200}Pt, {sup 201}Pt, {sup 202}Pt and {sup 203}Au, with half-lives ranging from approximately 10 ns to 1 ms. Tentative isomer information has been found also for {sup 174}Er, {sup 175}Er, {sup 185}Hf, {sup 191}Re, {sup 194}Re and {sup 199}Ir. In most cases, time-correlated, singles {gamma}-ray events provided the first spectroscopic data on excited states for each nuclide. In {sup 200}Pt and {sup 201}Pt, the assignments are supported by {gamma}-{gamma} coincidences. Isomeric ratios provide additional information, such as half-life and transition energy constraints in particular cases. The level structures of the platinum isotopes are discussed, and comparisons are made with isomer systematics. (orig.)

  10. Coherent harmonics of a Free Electron Laser obtained by the injection of harmonics produced in gas on the SCSS prototype accelerator

    Today, single-pass Free Electron Lasers (FELs) allow the structure of matter to be studied in the femtosecond domain. Yet, even if the produced radiation, the so-called Self Amplified Spontaneous Emission (SASE) is highly bright, the longitudinal coherence is partial; the spectral and temporal profiles are composed of a series of peaks, called 'spikes', and present important statistical fluctuations. We demonstrate here the strong and coherent amplification of the 5. harmonic of a Ti: Sa laser (800 nm, 10 Hz, 100 fs) generated in a gas cell, i.e. 160 nm, and seeded in a FEL. This spectacular phenomenon is associated to the generation of intense and coherent Non Linear Harmonics (NLH) at 54 nm and 32 nm. The experiment has been carried out on the SCSS (SPring-8 Compact SASE Source, Japan) Prototype Accelerator. This facility is mainly based on a thermionic cathode electron gun, a LINAC and an in-vacuum undulator (2 sections of 4.5 m length), in which the external harmonic source is overlapped transversally, spectrally and temporally with the electron beam (150 MeV, 10 Hz, 1 ps). With only one undulator section, the 160 nm seeded emission achieves three orders of magnitude higher intensity than the un-seeded one, and presents a quasi perfect Gaussian shape in the spectral distribution. Moreover, the FEL saturation length is twice smaller. In view of the low seed level required, such amplification associated to NLH schemes would allow the generation of fully coherent soft X-ray radiations down to the 'water window'. (author)

  11. Colorado Plateau Rapid Ecoregion Assessment Management Question A6: Where are hotspots producing fugitive dust that may contribute to accelerated snow melt in the Colorado Plateau?

    Bureau of Land Management, Department of the Interior — This map shows the factors that may contribute to potential dust sources that could contribute to accelerated snow melt. These factors include soil factors, low...

  12. Nuclide Transport and Diffusion for Vein and Fracture Flow

    Modelling radionuclide transport through crystalline rock is usually based on a small water flow in a system of narrow fractures. This flow is denoted as fracture flow. In our model, it implies planar water-conducting channels and adjacent zones of dominant matrix diffusion. According to the constitution of the rock, it can be necessary to consider additionally a vein flow being characterized by cylindrical water-conducting channels and adjacent zones of dominant matrix diffusion. Transport calculations, based on a dual porosity concept, were performed for vein as well as for fracture flow. An extensive discussion of the results provides an overview on important parameter dependencies and on the major vein flow effects. Formulae for quick estimates are given to guide quantitative interpretation of break-through curves. The discussion of analytical results for nuclide diffusion from a planar and from a cylindrical boundary backs up the comments on matrix diffusion. The following effects of vein flow onto the break-through curves are illustrative examples of useful findings: (1) The peak height can be very strongly reduced compared to fracture flow. The peak arrival time, however, is only slightly changed. (2) The asymptotic part of the tail is flatter than the well-known t-3/2 decrease for fracture flow. (3) The bump at the end of the tail, generated by the limitation of the diffusion zones, is substantially larger than for fracture flow. A double-peak break-through curve, therefore, can emerge from many cases of nuclide transport. (4) Sorption on the surfaces of diffusion-accessible pores can substantially change the break-through curves. The vein to fracture flow ratios of the break-through peak data, however, remain essentially equal. This holds for the whole range of investigated retardation factors from 7 to 27'000. The investigations presented contribute to sophisticated interpretations of break-through curves and improve the physical understanding of nuclide

  13. Nuclides having ENDF/B-V questionable data or errors

    All of the ENDF/B fission-product and actinide data have been incorporated into summation codes, including decay spectra, and aggregate comparisons were made with available measurements. Additional comparisons of many individual cross section and decay parameters with measurements and other evaluations have been made, and various consistency checks (e.g., the comparisons between average energies and values derived from spectra) have been made. Based on these comparisons and tests, we itemize here those nuclides and their parameters that should be reviewed for the next version of ENDF/B or before using the current Version-V data

  14. Atomic and nuclear parameters of single electron capture decaying nuclides

    Atomic and nuclear parameters of the following nuclides which decay by electron capture have been calculated: 37Ar, 41Ca, 49V, 53Mn, 55Fe,59Ni, 68Ge,82Sr, 97Tc, 118Te, 131Cs, 137La, 140Nd, 157Tb, 165Er, 193pt, 194Hg, and 205Ph The evaluation rules are included in the first part of the paper. The values and the associated uncertainties of the following parameters have been tabulated: decay energy, electron capture probabilities, fluorescence yield, electron emission and X-ray emission. (Author) 27 refs

  15. Formation of new actinide nuclides and their reaction cross section

    Helium jet transfer system, which had been designed and constructed for the study of actinide nuclides, was examined for the transfer efficiency of recoils and fission products formed in the nuclear reaction induced by α particles. The efficiency was found to be close to unity for products coming out of a 232Th target bombarded with 110 MeV α particles of intensity less than 40 nA. Residual radio-activities of a target chamber and a collection chamber were also measured. (author)

  16. An approach to advanced migration analysis of radioactive nuclides around near and far fields of underground radioactive waste disposal facilities

    The disposal of radioactive wastes produced from the consumption of nuclear fuel is one of the remaining most important problems. The objective of radioactive waste disposal is to isolate the wastes from the living environment of mankind till the radiation effect to mankind due to the radioactive nuclides contained in the wastes becomes negligible. As for the disposal method to attain the objective, various methods have been proposed corresponding to the kinds of radioactive wastes. One of the fundamental factors of the safety evaluation related to the disposal is the concentration of radioactive nuclides in groundwater. In this paper, the concept of the underground disposal of wastes and its relation to ground water are outlined, and by placing emphasis on the way of thinking of nuclide transfer and heat transfer model, the hydraulic approach to this problem is made by the new theory. In foreign countries, actual underground research facilities were constructed, and the related research activities have been carried out. Further, when the factors of superlong term are added, various new problems arise. (K.I.)

  17. Amaranthus gengaticus : the suitable vegetable for radioactive nuclide absorption in soil (K-40 and Cs-137)

    The experiment was set up to determine the quantities of radioactive nuclides which were absorbed by vegetables in Khon Kaen Province. The suitable vegetable would be used to be sampled for study of radioactive nuclide quantities (K-40 and Cs-137) in soil. Ten kinds of vegetables in the same market were corrected and pretreated by ovening to be ash at 450οc. Gamma-ray spectra of the samples were detected and analyzed for comparing the quantities of radioactive nuclides. Gamma-ray spectrometry with a HPGe detector was set up to detect and analyze radioactive nuclides and their quantities in ashes of vegetables. According to this study, amaranthus gengaticus, from ten vegetables, had the most quantities of radioactive nuclides. The amaranthus gengaticus, aged 45-60 days, can absorb the most quantities of radioactive nuclides

  18. Water hyacinth : the suitable aquatic weed for radioactive nuclide absorption in water

    The experiment was set up to determine the quantities of radioactive nuclides which were absorbed by aquatic weeds in Khon Kaen Province. The best aquatic weed would be used to be sampled for study of radioactive nuclide quantities in natural water resources. Seven kinds of aquatic weeds in the same site were corrected and pretreated by ovening to be ash at 450 οC. Gamma-ray spectra of the samples were detected and analyzed for comparing the quantities of radioactive nuclides. Gamma-ray spectrometry with a HPGe detector was set up to detect radioactive nuclides and their quantities in ashes of aquatic weeds. According to this study, water hyacinth, from seven aquatic weeds, had the most quantities of radioactive nuclides. The water hyacinth with 30 cm leaves in length can absorb the most quantities of radioactive nuclides

  19. Distributions of transuranium nuclides in sediment and biota of the North Atlantic Ocean

    The effects of the interaction of marine sediments with their biotic population on the penetration, redistribution, sediment association and biotic availability of delivered transuranium nuclides are discussed as a function of both sedimentation regimes and in-fauna populations. Data on the penetration and redistribution patterns of fall-out transuranium nuclides in the shallow sediments of Buzzards Bay, Massachusetts, are discussed in terms of the known parameters of sedimentation and 'in sediment' biological activity. In this (and most common) type of sedimentation regime, translocation of bioturbationally downmixed transuranium nuclides back toward (and probable loss from) the sediment surface is demonstrated. Various biological and biochemical mechanisms are advanced that may act on these nuclides within sediments. The increased availability to marine biota of sediment transuranium nuclides by these remobilization processes, is indicated by data showing accumulations of these nuclides in marine invertebrates and fish. (author)

  20. Distributions of transuranium nuclides in sediments and biota of the North Atlantic Ocean

    The effects of the interaction of marine sediments with their biotic population on the penetration, redistribution, sediment association and biotic availability of delivered transuranium nuclides are discussed as a function of both sedimentation regimes and in-fauna populations. Data on the penetration and redistribution patterns of fallout transuranium nuclides in the shallow sediments of Buzzards Bay, Massachusetts, are discussed in terms of the known parameters of sedimentation and in sediment biological activity. In this (and most common) type of sedimentation regime, translocation of bioturbationally downmixed transuranium nuclides back toward (and probable loss from) the sediment surface is demonstrated. Various biological and biochemical mechanisms are advanced that may act on these nuclides within sediments. The increased availability to marine biota of sediment transuranium nuclides by these remobilization processes is indicated by data showing accumulations of these nuclides in marine invertebrates and fish. Data are included on the distribution of 239Pu, 240Pu, 241Am, 137Cs, and 55Fe in the samples

  1. ISOLTRAP: An on-line penning trap for mass spectrometry on short-lived nuclides

    ISOLTRAP is a Penning trap mass spectrometer for high-precision mass measurements on short-lived nuclides installed at the on-line isotope separator ISOLDE at CERN. The masses of close to 300 radionuclides have been determined up to now. The applicability of Penning trap mass spectrometry to mass measurements of exotic nuclei has been extended considerably at ISOLTRAP by improving and developing this double Penning trap mass spectrometer over the past two decades. The accurate determination of nuclear binding energies far from stability includes nuclei that are produced at rates less than 100 ions/s and with half-lives well below 100 ms. The mass-resolving power reaches 107 corresponding to 10 keV for medium heavy nuclei and the uncertainty of the resulting mass values has been pushed down to below 10-8. The article describes technical developments achieved since 1996 and the present performance of ISOLTRAP. (orig.)

  2. ANDROS: A code for Assessment of Nuclide Doses and Risks with Option Selection

    Begovich, C.L.; Sjoreen, A.L.; Ohr, S.Y.; Chester, R.O.

    1986-11-01

    ANDROS (Assessment of Nuclide Doses and Risks with Option Selection) is a computer code written to compute doses and health effects from atmospheric releases of radionuclides. ANDROS has been designed as an integral part of the CRRIS (Computerized Radiological Risk Investigation System). ANDROS reads air concentrations and environmental concentrations of radionuclides to produce tables of specified doses and health effects to selected organs via selected pathways (e.g., ingestion or air immersion). The calculation may be done for an individual at a specific location or for the population of the whole assessment grid. The user may request tables of specific effects for every assessment grid location. Along with the radionuclide concentrations, the code requires radionuclide decay data, dose and risk factors, and location-specific data, all of which are available within the CRRIS. This document is a user manual for ANDROS and presents the methodology used in this code.

  3. ANDROS: A code for Assessment of Nuclide Doses and Risks with Option Selection

    ANDROS (Assessment of Nuclide Doses and Risks with Option Selection) is a computer code written to compute doses and health effects from atmospheric releases of radionuclides. ANDROS has been designed as an integral part of the CRRIS (Computerized Radiological Risk Investigation System). ANDROS reads air concentrations and environmental concentrations of radionuclides to produce tables of specified doses and health effects to selected organs via selected pathways (e.g., ingestion or air immersion). The calculation may be done for an individual at a specific location or for the population of the whole assessment grid. The user may request tables of specific effects for every assessment grid location. Along with the radionuclide concentrations, the code requires radionuclide decay data, dose and risk factors, and location-specific data, all of which are available within the CRRIS. This document is a user manual for ANDROS and presents the methodology used in this code

  4. ICoN, the Interactive Chart of Nuclides

    Lee, Kevin; Mumpower, Matthew; Aprahamian, Ani

    2015-10-01

    Nuclear data is critical to research fields from medicine to astrophysics. The chart of nuclides is a more descriptive version of the periodic table that can be used to visualize nuclear properties such as half-lives and mass. We have created ICoN (simply short for Interactive Chart of Nuclides), an API which can be used to visualize theoretical and experimental datasets. This visualization is achieved by using D3 (Data Driven Documents), HTML, and CSS3 to plot the elements and color them accordingly. ICoN features many customization options that users can access that are dynamically applied to the chart without reloading the page. Users can save the customized chart they create to various formats. We have constructed these features in order to provide a unique approach for researchers to interface with nuclear data. ICoN can also be used on all electronic devices without loss of support. We report on the current progress of this project and will present a working demo that highlights each aspect of the aforementioned features. This is the first time that all available technologies are put to use to make nuclear data more accessible than ever before. This is a first and we will make it available as open source ware.

  5. Dual nuclides SPECT for ventrilation and perfusion study

    Dual nuclides SPECT using 81mKr and 99mTc-MAA for ventilation and perfusion study was performed in 24 subjects. Cross talk of 81mKr to 99mTc-energy window was about 7.5% when ventilation and perfusion study were performed by 370 MBq of 81mKr gas and 185 MBq of 99mTc-MAA. Areas of low V/Q was significantly larger in SPECT study than in planar study, in 11 cases of various pulmonary diseases. High V/Q mismatches were also more clearly delineated in SPECT than in planar study. Dual nuclides SPECT study has advantages of obtaining V/Q distribution without movement artifacts and of simultaneous acquisition of ventilation and perfusion image. Area of high V/Q became larger in SPECT with cross talk than in SPECT without cross talk, but in the low V/Q area no significant difference was noted between SPECT with cross talk and without cross talk. (author)

  6. Exact error estimation for solutions of nuclide chain equations

    The exact solution of nuclide chain equations within arbitrary figures is obtained for a linear chain by employing the Bateman method in the multiple-precision arithmetic. The exact error estimation of major calculation methods for a nuclide chain equation is done by using this exact solution as a standard. The Bateman, finite difference, Runge-Kutta and matrix exponential methods are investigated. The present study confirms the following. The original Bateman method has very low accuracy in some cases, because of large-scale cancellations. The revised Bateman method by Siewers reduces the occurrence of cancellations and thereby shows high accuracy. In the time difference method as the finite difference and Runge-Kutta methods, the solutions are mainly affected by the truncation errors in the early decay time, and afterward by the round-off errors. Even though the variable time mesh is employed to suppress the accumulation of round-off errors, it appears to be nonpractical. Judging from these estimations, the matrix exponential method is the best among all the methods except the Bateman method whose calculation process for a linear chain is not identical with that for a general one. (author)

  7. Nuclear masses and properties of nuclei close to remote magical nuclide 100Sn

    Calculations of different nuclear properties are presented for nuclides close to the neutron deficient doubly magic 100Sn, which are intensively experimentally studied at the present time. Considered different nuclear properties include mass values for 25 nuclides around the core as well as the properties of excited states of the core and the core plus two quasiparticles nuclides. The problem of effective quadrupole charges and of the weak axial constant in nuclei close to 100Sn are also examined

  8. Modeling of electron beams produced by linear accelerator installed at CNSTN / optimization study for the case of radiation sterilization of medical products and pharmaceutical

    The evolution of particle accelerators has led to the disposal of a very wide diversity of applications, such as the technique of treatment with Beta radiations. an electron accelerator has been installed at the National Center for nuclear Sciences and Technologies CNSTN) with the aim of controlling this technology, its development and its use in the areas of agriculture, industry, human health and scientific research. this project is committed for the study of the exploitation of this new facility in the field of radio-sterilization of medical, pharmaceuticals, cosmetics and laboratory products. A numerical tool has been then developed to simulate the radio processing and to simplify this process. Due to this option of dose distribution modeling inside a studied product, it's possible to estimate the best configuration for the accelerator parameter setting. It is a solution allowing to guarantee at once the conformity of the treatment of a product, as well as the reliability of the installation.

  9. Experimental and theoretical study of the yields of residual product nuclei produced in thin targets irradiated by 100-2600 MeV protons

    Titarenko, Y E; Karpikhin, E I

    2003-01-01

    The objective of the project is measurements and computer simulations of independent and cumulative yields of residual product nuclei in thin targets relevant as target materials and structure materials for hybrid accelerator-driven systems coupled to high-energy proton accelerators. The yields of residual product nuclei are of great importance when estimating such basic radiation-technology characteristics of hybrid facility targets as the total target activity, target 'poisoning', buildup of long-lived nuclides that, in turn, are to be transmuted, product nuclide (Po) alpha-activity, content of low-pressure evaporated nuclides (Hg), content of chemically-active nuclides that spoil drastically the corrosion resistance of the facility structure materials, etc. In view of the above, radioactive product nuclide yields from targets and structure materials were determined by an experiment using the ITEP U-10 proton accelerator in 51 irradiation runs for different thin targets: sup 1 sup 8 sup 2 sup , sup 1 sup 8 ...

  10. Introducing the Fission-Fusion Reaction Process: Using a Laser-Accelerated Th Beam to produce Neutron-Rich Nuclei towards the N=126 Waiting Point of the r Process

    Habs, D; Gross, M; Allinger, K; Bin, J; Henig, A; Kiefer, D; Ma, W; Schreiber, J

    2010-01-01

    We propose to produce neutron-rich nuclei in the range of the astrophysical r process around the waiting point N=126 by fissioning a dense laser-accelerated thorium ion bunch in a thorium target (covered by a polyethylene layer), where the light fission fragments of the beam fuse with the light fission fragments of the target. Via laser Radiation Pressure Acceleration using a high-intensity, short pulse laser, very efficiently bunches of solid state density of 232Th can be generated from a first Th production target, placed on a CH2 backing. Laser accelerated Th ions with about 7 MeV/u will pass through a thin polyethylene layer placed in front of a thicker second Th foil closely behind the first target and desintegrate into light and heavy fission fragments. In addition light ions (p,C) from the CH2 backing of the first Th target will be accelerated as well, inducing the fission process of 232Th also in the second Th target. The laser-accelerated ion bunches with solid state density, which are about 10^15 ti...

  11. Ultra-short laser-accelerated proton pulses have similar DNA-damaging effectiveness but produce less immediate nitroxidative stress than conventional proton beams.

    Raschke, S; Spickermann, S; Toncian, T; Swantusch, M; Boeker, J; Giesen, U; Iliakis, G; Willi, O; Boege, F

    2016-01-01

    Ultra-short proton pulses originating from laser-plasma accelerators can provide instantaneous dose rates at least 10(7)-fold in excess of conventional, continuous proton beams. The impact of such extremely high proton dose rates on A549 human lung cancer cells was compared with conventionally accelerated protons and 90 keV X-rays. Between 0.2 and 2 Gy, the yield of DNA double strand breaks (foci of phosphorylated histone H2AX) was not significantly different between the two proton sources or proton irradiation and X-rays. Protein nitroxidation after 1 h judged by 3-nitrotyrosine generation was 2.5 and 5-fold higher in response to conventionally accelerated protons compared to laser-driven protons and X-rays, respectively. This difference was significant (p < 0.01) between 0.25 and 1 Gy. In conclusion, ultra-short proton pulses originating from laser-plasma accelerators have a similar DNA damaging potential as conventional proton beams, while inducing less immediate nitroxidative stress, which probably entails a distinct therapeutic potential. PMID:27578260

  12. Present status and future plan of research and development in JAEA on partitioning and transmutation technology for long-lived nuclides

    The Japan Atomic Energy Agency has been conducting research and development (R and D) on partitioning and transmutation (P and T) technology for long-lived nuclides in accordance with the Atomic Energy Commission's Research and Development of Technologies for Partitioning and Transmutation of Long-lived Nuclides - Status and Evaluation Report' issued in 2000. The present report reviews the progress of the investigation on the benefit and the cost of the P and T technology, the international trend of R and D, the progress and the future plan of R and D on the partitioning process and the transmutation cycle technology, together with the necessary infrastructure improvement including the Transmutation Experimental Facility as the Phase-II of the Japan Proton Accelerator Research Complex (J-PARC). (author)

  13. Nuclide creation and annealing reactor waste in neutron fields

    We consider chemical elements in the Universe (their properties and transmutations) as a fuel powering an evolution of stars, galaxies, etc. The nuclear fusion reactions represent an energy source of stars and, in particular, the Sun fitting the life on the Earth. This brings a question on an origin and conditions for creation of life. We discuss some specific features of nuclear reaction chains at the hydrostatic burning of nuclides in stars and treaties for development of thermonuclear fusion reactors at the Earth based environment. The nova and supernova give promising astrophysical site candidates for synthesis of heavy atomic nuclei and renewing other nuclear components. Such an explosive nucleosynthesis yields the actinides containing basic fuel for nuclear fission reactors, among others. We briefly outline the e-, s-, and r-processes while accounting for ultra-strong stellar magnetization, and discuss some ideas for annealing the radioactive toxic nuclear waste

  14. Radiometric dating by alpha spectrometry on uranium series nuclides

    This thesis describes the analytical and technical procedures that are required for routine application of both the 230Th/234U disequilibrium dating method for peat and the 210Pb dating method for lake sediments. Its principal aim is to test, refine and discuss the reliability and validity of these methods. On the other hand, the analytical procedures that were introduced open a wide range of other interesting fields of research that are not necessarily restricted to geological problems only. Chapter 5 reports an obviously not foreseen application: detection of alpha emitting nuclides released in the first weeks of May, 1986 during the accident with the nuclear power plant in Chernobyl, USSR. 128 refs.; 43 figs.; 15 tabs

  15. INTRACOIN: an international nuclide transport code intercomparison study

    To improve the understanding of various strategies for geospheric radionuclide tranport modelling an international cooperation project with ten participating organizations has been set up. In the project - INTRACOIN (Internatonal Nuclide Transport COde INtercomparison) study - a comparison between models is made on three levels with increasing complexity. Calculations are performed with some 20 computer codes representing different modelling strategies. The INTRACOIN study is limited in its scope to far-field radionuclide geosphere transport models. Thus, near-field models, groundwater hydraulics and models for transort in the biosphere are not included. However, since the geological barrier is an important part of the safety system the study should contribute to the understanding of important phenomena related to long-term safety assessments. In addition it provides a forum for discussion and for direct exchange of experience between experts in the field

  16. Method of eluting radioactive nuclide from spent ion exchange resin

    Highly radioactive spent ion exchange resins containing a great amount of cesium or strontium as radioactive nuclides are immersed in an eluting solution and, by stirring solution, cesium or strontium adsorbed to the spent ion exchange resins are eluted. The eluting solution is passed through a zeolite bed to selectively remove cesium and/or strontium. As an eluent for the eluting solution to be used, sodium salts such as sodium hydroxide or sodium sulfate is preferred. Zeolite having radiation resistance and not suffering from reduction in the absorbent performance by the presence of boric acid or sodium are used. Since the zeolite is highly stabilized with inorganic material by cement or glass solidification, the amount is remarkably reduced as compared with that of the spent resins and the administration is facilitated. (K.M.)

  17. Radioactive fallout nuclides in a peat-bog ecosystem

    The Province of Salzburg belongs to the regions with the highest contamination from the Chernobyl-fallout outside the former USSR. The peat-bog investigated in this study is situated in Koppl, east of Salzburg. A peat-bog is a special example of an ecosystem, which is generally not disturbed by human activities because it is under strict nature-conservation and whose soil structure is not affected by animal activities from moles and earthworms. Peat-bogs are characterized by acidic soils which are high in organic material and low in clay mineral content. A number of previous studies have demonstrated that especially in peat-bogs and especially in the Koppl-peat-bog very high amounts of radioactive fallout nuclides from the Chernobyl accident and from the bomb-testings could be found

  18. Selection of an optimized control nuclide to halt primary pumps

    Primary pumps are indispensable equipment to a nuclear power station. Besides maintaining the safe operation a unit, they play an un-replaceable function to control radiation source term. Selecting an optimized radionuclide to control the halt of primary pumps is an essential guide to deal with the problem between outage duration and reduction of radiation source term to a Pressurized Water Reactor (PWR) unit. From operational experiences of Daya Bay Nuclear Power Station (NPS), the author points out that 110mAg is the key nuclide which contributes largely to the radiation on the reactor unload/reload pool surface. The author also recommends a limit of 110mAg for halt of the primary pumps

  19. WWER-1000 spent fuel nuclide inventory at the Kozloduy NPP

    This paper contains a presentation and discussion of selected isotope inventory results for different types of WWER-1000 spent fuel assemblies. Nuclide inventory calculations of spent fuel assemblies at the Kozloduy NPP are routinely performed using the SCALE 4.4a computer code system. Besides the standard 17x17 ORIGEN-S library, a specific library developed at the Kozloduy NPP for each different fuel type at typical irradiation conditions is used. The evaluated concentrations of the most important isotopes - 235U, 236U, 238U, 239Pu, 240Pu, 241Pu, 242Pu - depending on burnup, are compared with fuel supplier data and with data calculated using the HELIOS-1.5 lattice code. The buildup of some other isotopes (237Np, 241Am, 243Am) is presented, too. (authors)

  20. WWER-1000 spent fuel nuclide inventory at the Kozloduy NPP

    This paper contains a presentation and discussion of selected isotope inventory results for different types of WWER-1000 spent fuel assemblies. Nuclide inventory calculations of spent fuel assemblies at Kozloduy NPP are routinely performed using the SCALE 4.4a computer code system. Besides the standard 17x17 ORIGEN-S library, a specific library developed at the Kozloduy NPP for each different fuel type at typical irradiation conditions is used. The evaluated concentrations of the most important isotopes-235U, 236U, 238U, 239Pu, 240Pu, 241Pu, 242Pu-depending on burnup, are compared with fuel supplier data and with data calculated using the HELIOS-1.5 lattice code. The buildup of some other isotopes (237Np, 241Am, 243Am) is presented, too (Authors)

  1. Interactive information system on the transmutation of nuclides in nuclear reactors

    An information system which can be used to calculate nuclide transmutation in nuclear reactors is described. The algorithms developed are based on a directed nuclide transformation graph and improve the speed of the calculations. The calculations are performed using a nuclear physics constants database with the latest evaluations which improves the reliability of the results obtained. (author)

  2. IDGAM. A PC code and database to help nuclide identification in activation analysis

    The document describes a PC diskette containing a code and database which helps researchers to identify the nuclides in a radioactive sample. Data can be retrieved by gamma-ray energy, nuclide or element. The PC diskette is available, costfree, from the IAEA Nuclear Data Section, upon request. (author). 6 refs, 5 figs

  3. A Study of the r-Process Path Nuclides,$^{137,138,139}$Sb using the Enhanced Selectivity of Resonance Ionization Laser Ionization

    Walters, W

    2002-01-01

    The particular features of the r-process abundances with 100 < A < 150 have demonstrated the close connection between knowledge of nuclear structure and decay along the r-process path and the astrophysical environement in which these elements are produced. Key to this connection has been the measurement of data for nuclides (mostly even-N nuclides) that lie in the actual r-process path. Such data are of direct use in r-process calculations and they also serve to refine and test the predictive power of nuclear models where little or no data now exist. In this experiment we seek to use the newly developed ionization scheme for the Resonance Ionization Laser Ion Source (RILIS) to achieve selective ionization of neutron-rich antimony isotopes in order to measure the decay properties of r-process path nuclides $^{137,138,139}$Sb. These properties include the half-lives, delayed neutron branches, and daughter $\\gamma$-rays. The new nuclear structure data for the daughter Te nuclides is also of considerable in...

  4. Nuclide analysis of an irradiated tantalum target of a spallation neutron source using high performance ion chromatography and inductively coupled plasma mass spectrometry

    Tantalum was used as target material in a spallation source where the neutrons are produced via spallation reactions between a highly energetic proton beam (Ep∼800 MeV) and the heavy tantalum target. The lanthanide metals were theoretically predicted in the irradiated tantalum target as a major fraction of spallation nuclides with quite significantly different nuclide abundances in comparison to the natural isotopic composition. Due to expected isobaric interferences of long-lived radionuclides and stable isotopes, all the lanthanide metals had to be separated chemically prior to their mass spectrometric determination by high performance ion chromatography (IC) after dissolution of tantalum in a HNO3/HF mixture and separation of the tantalum matrix by liquid-liquid extraction. An analytical procedure was applied for the determination of spallation nuclides of lanthanide metals in an irradiated tantalum target using IC coupled on-line to a sensitive double-focusing sector field inductively coupled plasma mass spectrometer (DF-ICP-MS).The experimental results of nuclide abundances of the lanthanides in the irradiated tantalum target obtained by on-line LC-ICP-MS are in good agreement with theoretically calculated values. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  5. Nuclides and pathways of relevance to the environmental monitoring programme for the Wackersdorf fuel reprocessing plant

    The relevant 14 nuclides (leading nuclides) have been determined that are to be observed within the radiological monitoring programme set up for normal operation of the Wackersdorf fuel reprocessing plant. These nuclides contribute about 99 p.c. of the total radiation exposure expected in the environs of the plant. Dispersion calculations have been made for these leading nuclides in accordance with the general instructions concerning the assessment of radiation exposure from radioactive effluents (Directives for the implementation of sec. 45, Radiation Protection Ordinance). Apart from the pathways mentioned in the above Directives, site-specific, additional pathways have been examined (as e.g. fish culture). An analysis of the various pathways of the individual nuclides shows the environmental materials to be observed by the monotoring programme. The results are explained in detail. (orig./PW)

  6. The introduction of radio nuclides over the atmosphere into the North Sea

    Although it is barely possible to provide exact data concerning the aerosol entry and the quantities of precipitation in the region of the North Sea, in the following an attempt will be made to estimate the annual entry of radio nuclides in the North Sea. As data for the calculations, available estimations of the quantity of precipitation over the sea, the content of radio nuclides in the air and in the rain over land and the activities conveyed thereby to the earth, as well as the emission quantities of radio nuclides with the exhaust air from nuclear energy plants, are applied. It is quite clear that Tritium represents by far the main part of the radio nuclides which enter the sea via the precipitation. The majority of the other artificial radio nuclides, on the other hand, are to be viewed as being quantitatively insignificant. (orig.)

  7. Approach to establishing safety margin for uncertainty in measurement and nuclide spectrum in clearance level inspection

    In the monitoring for compliance with the clearance level, the concentrations of objective nuclides, such as alpha or low-energy beta emitters, can be estimated without direct gamma measurement by assuming the existence of objective nuclides at geometric mean concentrations or by using previously assessed information on nuclide spectra and measurement results for a key gamma nuclide. To determine whether clearance can be carried out, the uncertainty in the mean concentrations and concentration ratios to the key gamma nuclide should be appropriately considered, in addition to the measurement uncertainty. In this work, the concept of the clearance level has been reconsidered and a new approach to establishing an appropriate safety factor of the monitoring for compliance with the clearance level has been proposed. This approach was adopted in the draft of standard of 'Monitoring for Compliance with Clearance Level' prepared by the Standards Committee (SC) of the Atomic Energy Society of Japan (AESJ). (author)

  8. Measuring the photon depth dose distribution produced by a medical linear accelerator in a water-equivalent radio-fluorogenic gel

    The present work describes use of a water equivalent radio-fluorogenic gel dosimeter for measurement of a depth dose distribution from a medical linear accelerator. Relative depth dose distributions for a 6 MV photon beam were measured with a novel radio-fluorogenic gel comprised of aqueous gelatin and coumarin-3-carboxylic acid. Agreement was within 3 % of published values in most areas of electronic equilibrium. Results support continued development of radio-fluorogenic gel dosimetry systems for quality assurance of clinical photon beams. (author)

  9. Transmutation of radioactive nuclides: basic conceptions and results

    The main results of radioactive waste transmutation (RWT) studies conducted in several nuclear centers are briefly overviewed. Particular attention has been given to the works performed in the Laboratory of High Energies of the Joint Institute for Nuclear Research (Dubna). We also point up the basic problems, which have to be solved to put the RWT on the practical level. In recent years one can notice increasing realization that the future energy production will be based for the most part on nuclear methods (for example, [1]). There is the multitude of varied reasons for such a point of view, which are the subjects of wide and continues discussion. We stress only that nuclear power do not consumes oxygen, i.e. one among the most important element of our biosphere and so do not disturb the ecological balance of our planet. Mention also that the present oxygen consumption caused by mankind reaches about 2% of the total uptake of this element and shows evidence of significant growth whereas the regeneration ability of nature decreases. But nuclear power must be safe and not producing hazardous radioactive waste (RW). It turned out to be quite possible in the so-called sub-critical or accelerator driving system (ADS) when the effective multiplication factor of neutrons may not excite -0.95 and the RW may be incinerated and transmuted to the acceptable rate [2], As an illustration Fig.l shows a schematic sketch of such an apparatus. In this way one can also considerably diminish the huge amount of about 200 000 tons of up till now accumulated RW, which derives mostly from operation of nuclear reactors and military devices and increasing of some 10 000 tons every year. These amount of RW makes very serious problems both from economic and ecological point of view

  10. A nuclear physics program at the Rare Isotope Beams Accelerator Facility in Korea

    Chang-Bum Moon

    2014-02-01

    Full Text Available This paper outlines the new physics possibilities that fall within the field of nuclear structure and astrophysics based on experiments with radioactive ion beams at the future Rare Isotope Beams Accelerator facility in Korea. This ambitious multi-beam facility has both an Isotope Separation On Line (ISOL and fragmentation capability to produce rare isotopes beams (RIBs and will be capable of producing and accelerating beams of wide range mass of nuclides with energies of a few to hundreds MeV per nucleon. The large dynamic range of reaccelerated RIBs will allow the optimization in each nuclear reaction case with respect to cross section and channel opening. The low energy RIBs around Coulomb barrier offer nuclear reactions such as elastic resonance scatterings, one or two particle transfers, Coulomb multiple-excitations, fusion-evaporations, and direct capture reactions for the study of the very neutron-rich and proton-rich nuclides. In contrast, the high energy RIBs produced by in-flight fragmentation with reaccelerated ions from the ISOL enable to explore the study of neutron drip lines in intermediate mass regions. The proposed studies aim at investigating the exotic nuclei near and beyond the nucleon drip lines, and to explore how nuclear many-body systems change in such extreme regions by addressing the following topics: the evolution of shell structure in areas of extreme proton to neutron imbalance; the study of the weak interaction in exotic decay schemes such as beta-delayed two-neutron or two-proton emission; the change of isospin symmetry in isobaric mirror nuclei at the drip lines; two protons or two neutrons radioactivity beyond the drip lines; the role of the continuum states including resonant states above the particle-decay threshold in exotic nuclei; and the effects of nuclear reaction rates triggered by the unbound proton-rich nuclei on nuclear astrophysical processes.

  11. Can Accelerators Accelerate Learning?

    The 'Young Talented' education program developed by the Brazilian State Funding Agency (FAPERJ)[1] makes it possible for high-schools students from public high schools to perform activities in scientific laboratories. In the Atomic and Molecular Physics Laboratory at Federal University of Rio de Janeiro (UFRJ), the students are confronted with modern research tools like the 1.7 MV ion accelerator. Being a user-friendly machine, the accelerator is easily manageable by the students, who can perform simple hands-on activities, stimulating interest in physics, and getting the students close to modern laboratory techniques.

  12. DCHAIN 2: a computer code for calculation of transmutation of nuclides

    DCHAIN2 is a one-point depletion code which solves the coupled equation of radioactive growth and decay for a large number of nuclides by the Bateman method. A library of nuclear data for 1170 fission products has been prepared for providing input data to this code. The Bateman method surpasses the matrix exponential method in computational accuracies and in saving computer storage for the code. However, most existing computer codes based on the Bateman method have shown serious drawbacks in treating cyclic chains and more than a few specific types of decay chains. The present code has surmounted the above drawbacks by improving the code FP-S, and has the following characteristics: (1) The code can treat any type of transmutation through decays or neutron induced reactions. Multiple decays and reactions are allowed for a nuclide. (2) Unknown decay energy in the nuclear data library can be estimated. (3) The code constructs the decay scheme of each nuclide in the code and breaks it up into linear chains. Nuclide names, decay types and branching ratios of mother nuclides are necessary as the input data for each nuclide. Order of nuclides in the library is arbitrary because each nuclide is destinguished by its nuclide name. (4) The code can treat cyclic chains by an approximation. A library of the nuclear data has been prepared for 1170 fission products, including the data for half-lives, decay schemes, neutron absorption cross sections, fission yields, and disintegration energies. While DCHAIN2 is used to compute the compositions, radioactivity and decay heat of fission products, the gamma-ray spectrum of fission products can be computed also by a separate code FPGAM using the composition obtained from DCHAIN2. (J.P.N.)

  13. User manual of nuclide dispersion in phreatic aquifers model

    The Nuclide Dispersion in Phreatic Aquifers (DRAF) model was developed in the 'Division Estudios Ambientales' of the 'Gerencia de Seguridad Radiologica y Nuclear, Comision Nacional de Energia Atomica' (1991), for the Safety Assessment of Near Surface Radioactive Waste Disposal Facilities. Afterwards, it was modified in several opportunities, adapting it to a number of application conditions. The 'Manual del usuario del codigo DRAF' here presented is a reference document for the use of the last three versions of the code developed for the 'Autoridad Regulatoria Nuclear' between 1995 and 1996. The DRAF model solves the three dimension's solute transport equation for porous media by the finite differences method. It takes into account the advection, dispersion, radioactive decay, and retention in the solid matrix processes, and has multiple possibilities for the source term. There are three versions of the model, two of them for the saturated zone and one for the unsaturated zone. All the versions have been verified in different conditions, and have been applied in exercises of the International Atomic Energy Agency and also in real cases. (author)

  14. Production and Recoil Loss of Cosmogenic Nuclides in Presolar Grains

    Trappitsch, Reto; Leya, Ingo

    2016-05-01

    Presolar grains are small particles that condensed in the vicinity of dying stars. Some of these grains survived the voyage through the interstellar medium (ISM) and were incorporated into meteorite parent bodies at the formation of the Solar System. An important question is when these stellar processes happened, i.e., how long presolar grains were drifting through the ISM. While conventional radiometric dating of such small grains is very difficult, presolar grains are irradiated with galactic cosmic rays (GCRs) in the ISM, which induce the production of cosmogenic nuclides. This opens the possibility to determine cosmic-ray exposure (CRE) ages, i.e., how long presolar grains were irradiated in the ISM. Here, we present a new model for the production and loss of cosmogenic 3He, 6,7Li, and 21,22Ne in presolar SiC grains. The cosmogenic production rates are calculated using a state-of-the-art nuclear cross-section database and a GCR spectrum in the ISM consistent with recent Voyager data. Our findings are that previously measured 3He and 21Ne CRE ages agree within the (sometimes large) 2σ uncertainties and that the CRE ages for most presolar grains are smaller than the predicted survival times. The obtained results are relatively robust since interferences from implanted low-energy GCRs into the presolar SiC grains and/or from cosmogenic production within the meteoroid can be neglected.

  15. Baseline concentrations of nuclear fuel waste nuclides in the environment

    Protection of the environment is a key issue in the disposal of long-lived radioactive wastes. To assess the implications of undergound disposal, transport models are commonly used to predict radionuclide concentrations in soil and water. However, an appropriate framework needs to be established to ensure that the predicted concentrations do not impose unacceptable environmental impacts. Here, we suggest baseline environmental concentrations of the most important radionuclides in nuclear fuel waste. We summarize background concentrations of the nuclides in soil and surface water, and suggest Environmental Increments (EI) that could be added to soil and water without causing detectable effects. The EI values are based mostly on natural variability, but some alternative methods are used for radionuclides that are very rare in nature. The background concentrations and EI values are most useful as a screening tool to help identify potentially unacceptable concentrations arising from a disposal concept. When available, we also report data on concentrations that have been measured in the environment without causing an observable effect. This review focuses especially on concentrations applicable to the Canadian Precambrian Shield, as part of the Canadian concept of nuclear fuel waste disposal in a deep, stable geological formation

  16. Computer models for nuclide migration from radioactive waste repositories

    The object of this study is to assess the possible release of radionuclides from shallow trench repositories by interaction with groundwater. To achieve this aim an appreciation of the strategy of computer modelling was required and in the course of this work some calculations will be carried out using a simple computer model. A review of the literature on nuclide migration models was therefore carried out which covered the basic theory, data requirements and limitations of use of such models. This review is by no means a complete survey of existing codes but is intended as a guide to the mathematical basis of the models for the non-specialist, indicating those parameters which influence the eventual radionuclide release. At this stage a very sophisticated model is not required, and therefore this review has concentrated mainly on simple, one dimensional codes. Two such codes have been run for five test cases in order to compare their results with each other and with the results of other codes published in the literature. (author)

  17. Decontamination of contaminated oils with radio nuclides using magnetic fields

    The present work is focused in to find a solution to the wastes treatment that are generated during the maintenance to the nuclear power industry, the specify case of the contaminated oils with radio nuclides, for this purpose was necessary to make a meticulous characterization of the oils before the treatment proposal using advanced techniques, being determined the activity of them, as well as their physical-chemical characteristics. By means of the developed procedure that combines the use of magnetic fields and filtration to remove the contaminated material with radioactive particles, is possible to diminish the activity of the oils from values that oscillate between 6,00 and 10,00 up to 0,00 to 0,0003 Bq/ml. The decontamination factor of the process is of 99.00%. The proposal of the necessary technology for to decontaminate the oils is also made and is carried out the economic analysis based on the reuse of these, as well as the calculation of the avoided damages. (Author)

  18. A study on nuclide migration in buffer materials and rocks for geological disposal of radioactive waste

    Sato, Haruo [Power Reactor and Nuclear Fuel Development Corp., Tokai, Ibaraki (Japan). Tokai Works

    1998-01-01

    This thesis summarizes the results investigated in order to establish a basic theory on the predictive method of diffusion coefficients of nuclides in compacted sodium bentonite which is a candidate buffer material and in representative rocks for the geological disposal of radioactive waste by measuring the pore structural factors of the compacted bentonite and rocks such as porosity and tortuosity, measuring diffusion coefficients of nuclides in the bentonite and rocks, acquiring basic data on diffusion and developing diffusion models which can quantitatively predict nuclide migration in long-term. (J.P.N.). 117 refs.

  19. Industrial applications of electron accelerators

    Cleland, M R

    2006-01-01

    This paper addresses the industrial applications of electron accelerators for modifying the physical, chemical or biological properties of materials and commercial products by treatment with ionizing radiation. Many beneficial effects can be obtained with these methods, which are known as radiation processing. The earliest practical applications occurred during the 1950s, and the business of radiation processing has been expanding since that time. The most prevalent applications are the modification of many different plastic and rubber products and the sterilization of single-use medical devices. Emerging applications are the pasteurization and preservation of foods and the treatment of toxic industrial wastes. Industrial accelerators can now provide electron energies greater than 10 MeV and average beam powers as high as 700 kW. The availability of high-energy, high-power electron beams is stimulating interest in the use of X-rays (bremsstrahlung) as an alternative to gamma rays from radioactive nuclides.

  20. Accelerator business in Japan expanding

    Accelerators have become to be used increasingly in Japan in such fields as medicine, physics research and industry. This has caused stiff competition for market share by the manufacturers of accelerators. Electron beam accelerators for industrial use provide an indispensable means for adding values to products, for example, electric cables with incombustible insulators. Linear accelerators for the nondestructive inspection of nuclear components have been widely installed at equipment manufacturing plants. Active efforts have been exerted to develop small synchrotron radiation accelerators for next generation electronic industry. Cyclotrons for producing short life radioisotopes for medical diagnosis and electron beam accelerators for radiation therapy are also used routinely. The suppliers of accelerators include the companies manufacturing heavy electric machinery, heavy machinery and the engineering division of steelmakers. Accelerator physics is being formed, but universities do not yet offer the course regarding accelerators. Accelerator use in Japan and the trend of accelerator manufacturers are reported. (K.I.)

  1. Linear Accelerators

    Vretenar, M

    2014-01-01

    The main features of radio-frequency linear accelerators are introduced, reviewing the different types of accelerating structures and presenting the main characteristics aspects of linac beam dynamics.

  2. Nuclear Data Requirements for the Production of Medical Isotopes in Fission Reactors and Particle Accelerators

    Garland, M A; Talbert, R J; Mashnik, S G; Wilson, W B

    1999-01-01

    Through decades of effort in nuclear data development and simulations of reactor neutronics and accelerator transmutation, a collection of reaction data is continuing to evolve with the potential of direct applications to the production of medical isotopes. At Los Alamos the CINDER'90 code and library have been developed for nuclide inventory calculations using neutron-reaction (En < 20 MeV) and/or decay data for 3400 nuclides; coupled with the LAHET Code System (LCS), irradiations in neutron and proton environments below a few GeV are tractable; additional work with the European Activation File, the HMS-ALICE code and the reaction models of MCNPX (CEM95, BERTINI, or ISABEL with or without preequilibrium, evaporation and fission) have been used to produce evaluated reaction data for neutrons and protons to 1.7 GeV. At the Pacific Northwest National Laboratory, efforts have focused on production of medical isotopes and the identification of available neutron reaction data from results of integral measuremen...

  3. Accelerators Beyond The Tevatron?

    Lach, Joseph; /Fermilab

    2010-07-01

    Following the successful operation of the Fermilab superconducting accelerator three new higher energy accelerators were planned. They were the UNK in the Soviet Union, the LHC in Europe, and the SSC in the United States. All were expected to start producing physics about 1995. They did not. Why?

  4. Monte Carlo modeling of 6 MV photon beam produced by the elekta precise linear accelerator of Tripoli medical center using beamnrc/dosexyznrc

    The 6MV photon beam production by the Elekta Line accelerateur of Tripoli of medical center (TMC) was modeled using Beamnrc and Dosexyzne Monte Carlo codes. The Beamnrc code was used to model the accelerator head and generate phase files. The phase space files were then used as input to the Dosexyzne code to simulate octogenarian deth dose and beam profiles. simulation were first stared using nominal provided by the vendor, a field size of 10x10cm2 and Source to surface distance (SSD) of 100 cm. simulation were compared with experimental data and energy tuning procedures were applied to validate the model. Energy tuning procedures indicated that the nominal energy of 6 MV and a FWHM of the Gaussian distribution of the source of 0.35 cm were the optimal energy and FWHM for the model. The depth of maximum dose at 6 MV was found to be 1.5 cm. The percentage relative differences between calculated and experimental Pdd(s) ranged from 0.5% to 3% for field size of 10cm2 and reached a value of 8% at depths greater than 20cm, The model was later used to calculate PDD(s) and beam profile and output factors for different field size ranging from 3x3cm2 to 25x25cm2. Calculated output factors were in good agreement with experimental values (the percentage relative differences ranged from 1% to 4%). (Author)

  5. Book Review: Radiation protection and measurement issues related to cargo scanning with accelerator-produced high-energy X rays, NCRP Commentary No. 20

    Having spent roughly the first third of his health physics career on the Norfolk, VA waterfront area, the reviewer was excited to see the NCRP Commentary 20, 'Radiation Protection and Measurements Issues Related to Cargo Scanning with Accelerator Technology'. It signals the advent of the Cargo Advanced Automated Radiography System (CAARS). The waterfront is a border that challenges physical security programs and technology. As Commentary 20 provides in the introduction, waterfront cargo terminals and land border crossings together represent over 300 ports of entry in the USA. Every year, the USA receives over 10 million cargo containers from commercial shipping and a roughly equal amount from land border crossings. While rapidly processing containerized cargo, CAARS will be able to detect small quantities of high atomic number radioactive materials and dense shielding materials used for radioactive gamma ray sources and even illicit human cargo - important concerns for homeland security. It will also be able to detect other contraband such as explosives, weapons and drugs. Section 1 of the Commentary presents an executive summary with NCRP's radiation dose management recommendations and related operational recommendations for effective implementation of CAARS technology in the current regulatory environment.

  6. Book Review: Radiation protection and measurement issues related to cargo scanning with accelerator-produced high-energy X rays, NCRP Commentary No. 20

    Robert May

    2008-11-01

    Having spent roughly the first third of his health physics career on the Norfolk, VA waterfront area, the reviewer was excited to see the NCRP Commentary 20, 'Radiation Protection and Measurements Issues Related to Cargo Scanning with Accelerator Technology'. It signals the advent of the Cargo Advanced Automated Radiography System (CAARS). The waterfront is a border that challenges physical security programs and technology. As Commentary 20 provides in the introduction, waterfront cargo terminals and land border crossings together represent over 300 ports of entry in the USA. Every year, the USA receives over 10 million cargo containers from commercial shipping and a roughly equal amount from land border crossings. While rapidly processing containerized cargo, CAARS will be able to detect small quantities of high atomic number radioactive materials and dense shielding materials used for radioactive gamma ray sources and even illicit human cargo - important concerns for homeland security. It will also be able to detect other contraband such as explosives, weapons and drugs. Section 1 of the Commentary presents an executive summary with NCRP's radiation dose management recommendations and related operational recommendations for effective implementation of CAARS technology in the current regulatory environment.

  7. Nuclides.net: An integrated environment for computations on radionuclides and their radiation

    Full text: The Nuclides.net computational package is of direct interest in the fields of environment monitoring and nuclear forensics. The 'integrated environment' is a suite of computer programs ranging from a powerful user-friendly interface, which allows the user to navigate the nuclide chart and explore the properties of nuclides, to various computational modules for decay calculations, dosimetry and shielding calculations, etc. The main emphasis in Nuclides.net is on nuclear science applications, such as health physics, radioprotection and radiochemistry, rather than nuclear data for which excellent sources already exist. In contrast to the CD-based Nuclides 2000 predecessor, Nuclides.net applications run over the internet on a web server. The user interface to these applications is via a web browser. Information submitted by the user is sent to the appropriate applications resident on the web server. The results of the calculations are returned to the user, again via the browser. The product is aimed at both students and professionals for reference data on radionuclides and computations based on this data using the latest internet technology. It is particularly suitable for educational purposes in the nuclear industry, health physics and radiation protection, nuclear and radiochemistry, nuclear physics, astrophysics, etc. The Nuclides.net software suite contains the following modules/features: a) A new user interface to view the nuclide charts (with zoom features). Additional nuclide charts are based on spin, parity, binding energy etc. b) There are five main applications: (1) 'Decay Engine' for decay calculations of numbers, masses, activities, dose rates, etc. of parent and daughters. (2) 'Dosimetry and Shielding' module allows the calculation of dose rates from both unshielded and shielded point sources. A choice of 10 shield materials is available. (3) 'Virtual Nuclides' allows the user to do decay and dosimetry and shielding calculations on mixtures of

  8. Fate of nuclides in natural water systems. Annual progress report, April 1, 1983-March 31, 1984

    This study of the behavior of nuclides in natural water systems is divided into studies of atmospheric aerosols, soils, groundwater, rivers, estuaries and coastal zones, the carbon cycle and the growth rates of marine organisms

  9. Calculation of fissile nuclides and fission products inventory applied to ETRR-1 research reactor

    The study of the nuclear reactor fuel safety implies studying physical mechanical, thermal and chemical proportions of the fuel during normal operation and accident conditions. A model was developed to calculate the fissile nuclides and fission products inventory in an operating reactor. The model considers the production and removal of different radionuclides leaking into account the decay schemes of each. The mathematical formulas were treated without any approximations. A decay model was developed for the period after reactor shutdown. The amount of different nuclides was evaluated for a given cooling time. Egypt test and research reactor number 1, ETRR-1. Was chosen to apply the model. The amount of about 200 nuclides was calculated. A certain nuclides was chosen to be presented based on their poisoning ratios. Criticality calculations were carried out to investigate the criticality condition of the reactor at different operating times. 4 fig

  10. Nuclear Physics Programs for the Future Rare Isotope Beams Accelerator Facility in Korea

    Moon, Chang-Bum

    2016-01-01

    We present nuclear physics programs based on the planned experiments using rare isotope beams (RIBs) for the future Korean Rare Isotope Beams Accelerator facility; RAON. This ambitious facility has both an Isotope Separation On Line (ISOL) and fragmentation capability for producing RIBs and accelerating beams of wide range mass of nuclides with energies of a few to hundreds MeV per nucleon. Low energy RIBs at Elab = 5 to 20 MeV per nucleon are for the study of nuclear structure and nuclear astrophysics toward and beyond the drip lines while higher energy RIBs produced by in-flight fragmentation with the re-accelerated ions from the ISOL enable to explore the neutron drip lines in intermediate mass regions. The planned programs have goals for investigating nuclear structures of the exotic nuclei toward and beyond the nucleon drip lines by addressing the following issues: how the shell structure evolves in areas of extreme proton to neutron imbalance; whether the isospin symmetry maintains in isobaric mirror nu...

  11. Constraining landscape development of the Sri Lankan escarpment with cosmogenic nuclides in river sediment

    V. Vanacker; Friedhelm von Blanckenburg; T. Hewawasam; P. W. Kubik;  ,

    2007-01-01

    Escarpments are prominentmorphological features along high-elevation passive margins. Recent studies integrating geomorphology, thermochronology, and cosmogenic nuclide-based denudation rate estimates suggest a rapid phase of denudation immediately after the earliest stages of seafloor spreading, and subsequent slow denudation rates since. To constrain the geomorphic evolution of passive margins, we have examined the development of the Sri Lankan escarpment. Cosmogenic nuclide data on river s...

  12. Determination of ultra-trace amounts of nuclides by sensitive inorganic mass spectrometry

    Recent development of ICP (Inductively Coupled Plasma) mass spectrometry has a potential to detect very tiny amounts of radioactive nuclides owing to its high sensitivity. The detection of long-lived nuclides such as 236U, 135Cs, and 129I has been reported in the recent years. In this review, principle of inorganic mass spectrometry (MS) and characteristics of ICP are explained, and their detection limits are compared with those obtained by conventional radiation measurements. (author)

  13. Measurement of specific radioactivity of 125I, 139Ce, etc 7 kinds of nuclide solution

    The decay characteristic of 125I, 139Ce, 88Y, 57Co, 60Co, 137Cs and 134Cs radio-nuclide and the principle for measurement of specific activity of the seven kinds of nuclide with coincidence method, 4πγ ionization room method, spectroscopy method and summing peak method are simply is described. The results compare with the measurement result from National Institute of Metrology P.R. China, they are agreeable within uncertainty. (authors)

  14. Novel reprocessing methods with nuclide separation for volume reduction of high level radioactive waste

    We have proposed the reprocessing system with nuclide separation processes based on the chromatographic technique in the hydrochloric acid solution system. Our proposing system consists of the dissolution process, the reprocessing process, the MA separation process, and nuclide separation processes. In our proposing processes, the pyridine resin is used as a main separation media. We expect that our proposing will contribute to that volume reduction of high level radioactive waste by combining the transmutation techniques, usage of valuable elements, and so on. (author)

  15. Application of activable stable nuclide tracers to the soil erosion study

    The present application of activable stable nuclide tracers to the study of soil erosion is discussed. The rare earth element tracers are taken as an example and the emphasis is placed on the application and prospect of the activable nuclide tracer method. Experimental results have shown that the method has a great future in the studies on spatial and temporal distributions of soil erosion, sediment movement and deposition process as well as the sediment origin in small watershed

  16. Partitioning of long-lived nuclides from radioactive waste. FY 1975 annual report

    Wheelwright, E.J.

    1976-04-01

    The status of the following studies is reported: characterization and treatment of solids in high-level waste; removal of long-lived nuclides from solidified waste and non-high-level wastes; development of low-additive flowsheets for removing long-lived nuclides from the fission products; evaluation of incentives for partitioning; and comparison of waste management systems with and without partitioning. (LK)

  17. Effects of up scattering by heavy nuclides on Doppler changes of resonance adsorption

    A procedure for handling energy changes of neutrons accurately in a Monte Carlo code, within the large resonances of heavy nuclides, is discussed. The procedure has been applied in the MCNP program to sample problem which relates to PWR unit cells. The statistical uncertainties in estimating the effect of neutron up scattering in pronounced resonances of heavy nuclides on resonance absorption rates, and their temperature changes, are discussed. (author). 10 refs

  18. Analysis of neonicotinoids by gas chromatography coupled to nuclide 63Ni - Electron Capture Detector - GC/ECD

    Recently, several reports have been published discussing reduction in bee population which polymerizes cultures around the world this phenomenon is known as Colony Collapse Disorder (CCD). The phenomenon describes the lack of worker honeybees in the colony despite having pups and food. The causes of this problem are unknown but there are studies that claim that reduction of population of bees is linked to poisoning through insecticides specifically neonicotinoids. Among this type of pesticide are imidacloprid (C9H10ClN5O2), clothianidin (C6H8ClN5O2S) and thiamethoxam (C8H10ClN5O3S). This paper presents the analysis of neonicotinoids - clothianidin, imidacloprid and thiamethoxam - by the technique of gas chromatography coupled to nuclide 63Ni electron capture detector (GC/ECD). The electron capture detector (ECD) is a gas chromatography detector that has been used for the detection of organic halogens, nitriles, nitrates and organometallic compounds. The ECD detector ionizes the analytes by the beta particles from the nuclide sources 63Ni within carrier gas N2. The electrons produced in this process are collected and create a current that are amplified and generates a chromatographic peak. Methodology and details of the analysis are present in this work. (author)

  19. Analysis of neonicotinoids by gas chromatography coupled to nuclide {sup 63}Ni - Electron Capture Detector - GC/ECD

    Amaral, Priscila O.; Leao, Claudio; Redigolo, Marcelo M.; Crepaldi, Caike; Bustillos, Oscar V., E-mail: priscilaoamaral@gmail.com, E-mail: claudio.leao@usp.br, E-mail: marceloredigolo@gmail.com, E-mail: caike1995@gmail.com, E-mail: ovega@ipen.bremails [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Recently, several reports have been published discussing reduction in bee population which polymerizes cultures around the world this phenomenon is known as Colony Collapse Disorder (CCD). The phenomenon describes the lack of worker honeybees in the colony despite having pups and food. The causes of this problem are unknown but there are studies that claim that reduction of population of bees is linked to poisoning through insecticides specifically neonicotinoids. Among this type of pesticide are imidacloprid (C{sub 9}H{sub 10}ClN{sub 5}O{sub 2}), clothianidin (C{sub 6}H{sub 8}ClN{sub 5}O{sub 2}S) and thiamethoxam (C{sub 8}H{sub 10}ClN{sub 5}O{sub 3}S). This paper presents the analysis of neonicotinoids - clothianidin, imidacloprid and thiamethoxam - by the technique of gas chromatography coupled to nuclide {sup 63}Ni electron capture detector (GC/ECD). The electron capture detector (ECD) is a gas chromatography detector that has been used for the detection of organic halogens, nitriles, nitrates and organometallic compounds. The ECD detector ionizes the analytes by the beta particles from the nuclide sources {sup 63}Ni within carrier gas N{sub 2}. The electrons produced in this process are collected and create a current that are amplified and generates a chromatographic peak. Methodology and details of the analysis are present in this work. (author)

  20. Erosion of mountain plateaus along Sognefjord, Norway, constrained by cosmogenic nuclides

    Andersen, Jane Lund; Egholm, David L.; Knudsen, Mads F.; Linge, Henriette; Jansen, John D.

    2016-04-01

    Norway is famous for its deeply incised, steep-sided fjords, carved out by glacial erosion. The high relief of the fjords stands in contrast to the extensive areas of relatively low relief found between the fjords. The origin and development of these low-relief areas remain debated. The classical interpretation relates them to a Mesozoic peneplanation surface, uplifted to the current high elevation in the early Cenozoic (e.g. Nesje, 1994). The validity of this interpretation has, however, been repeatedly questioned in recent times (e.g. Nielsen et al. 2009, Steer et al. 2012). Recent studies point instead to a significant impact of glacial and periglacial erosion processes on the long-term development of the low-relief surfaces (Egholm et al. 2015). Here, we present a large new dataset of in-situ produced cosmogenic 10Be and 26Al in bedrock and boulders from the high, flat summit surfaces along a transect from the coast to the inner parts of Sognefjorden in Norway. Our results indicate substantial glacial modification of the sampled low-relief surfaces within the last 50 ka. Close to the coast, at an elevation of around 700 meters, the cosmogenic nuclide signal was reset around the Younger Dryas due to extensive glacial erosion. Regarding the higher surfaces further inland, our results indicate a maximum cosmogenic nuclide inheritance of 20-30 ka prior to the last deglaciation. We do not find any signs of exceptional longevity of the low-relief landscape. In contrast, our results indicate that the low-relief areas were continuously eroded by glacial and periglacial processes in the Quaternary. Nesje & Whillans. Erosion of Sognefjord, Norway. Geomorphology 9(1), 33-45, 1994. Nielsen et al. The evolution of western Scandinavian topography: a review of Neogene uplift versus the ICE (isostasy-climate-erosion) hypothesis. Journal of Geodynamics 47(2), 72-95, 2009. Steer et al. Bimodal Plio-Quaternary glacial erosion of fjords and low-relief surfaces in Scandinavia

  1. A Study on the Nuclide Migration and Retardation Using Natural Barrier

    In this study, we investigated the properties of geochemical reactions and sorption of high-level radionuclides (U, Th, Am, and Np), constructed databases for the geochemical reactions and sorption of the high-level radionuclides, and developed application methodologies of the databases. For the investigation on the nuclide migration and retardation through fractured rocks in KURT, in-situ solute migration system and on-line monitoring system were installed. The migration and retardation behaviors of nuclides were investigated annually for non-sorbing, simply sorbing and multi-valent sorbing nuclides, respectively, and interactions with fracture-filling materials were also analyzed. Besides, researches difficult to perform in KURT were carried out in foreign underground research facilities as joint studies for nuclide and colloid migration. The results from domestic and foreign underground facilities were compared each other and the reliability of the domestic results were assured from this. Diffusion depths of high-level radionuclides into rock matrix were measured in KURT conditions and their diffusion properties were analyzed and evaluated. In addition, the effects of bio-mineralization and redox reactions of a nuclide and microbe on nuclide behaviors were carried out to study the effects of combined interactions between minerals and microbes on the radionuclide migration and retardation

  2. TRIGA-TRAP: A Penning trap setup for mass measurements on exotic and heavy nuclides

    The research reactor Triga Mainz offers unique possibilities for on-line mass measurements on neutron-rich isotopes as produced by fission of U-235, Pu-239 or Cf-249 targets. In addition, off-line measurements of actinide elements up to Cf-252 are planned. To this end a new Penning trap mass spectrometer will be installed at Triga Mainz, featuring not only the commonly used time-of-flight resonance technique, but also the non-destructive narrow-band image current technique, enabling the detection of a single singly-charged ion stored in the trap. Triga-Trap is the first on-line mass spectrometer for singly-charged heavy ions using this image current detection technique in combination with cryogenic Penning traps. In case of many heavy and superheavy nuclides, the production rates are often less than a few ions per second, but some isotopes exhibit comparably long half-lives in the order of seconds, which allows for repeated measurement cycles on the same trap content. Measurements with the newly developed narrow-band FT-ICR system at Triga-Trap will also serve as tests for future experiments at SHIPTRAP at GSI or MATS at FAIR

  3. Tantalum-178 - a short-lived nuclide for nuclear medicine: production of the parent W-178

    The physical decay characteristics of the short-lived radionuclide Ta-178 (half-life 9.3 min) appear to be suitable for use in conjunction with low-energy detection systems such as the multiwire proportional camera. This camera is inefficient for emissions with energies greater than 100 keV. The gamma-ray spectrum of Ta-178 is dominated by the characteristic hafnium x-rays (55 to 65 keV), emitted as a result of electron-capture decay. The parent nuclide, W-178 (half-life 21.7 d), was produced in the Michigan State University cyclotron by proton bombardment of stacked natural tantalum-foil targets. Optimum production was found to occur with an incident proton energy of 34 MeV at an effective activity of 1.1 mCi/μA-hr per MeV of target thickness. Tungsten-178 was chemically separated from the Ta foils with a yield of 98%

  4. Leaky Fermi accelerators

    Shah, Kushal; Rom-Kedar, Vered; Turaev, Dmitry

    2015-01-01

    A Fermi accelerator is a billiard with oscillating walls. A leaky accelerator interacts with an environment of an ideal gas at equilibrium by exchange of particles through a small hole on its boundary. Such interaction may heat the gas: we estimate the net energy flow through the hole under the assumption that the particles inside the billiard do not collide with each other and remain in the accelerator for sufficiently long time. The heat production is found to depend strongly on the type of the Fermi accelerator. An ergodic accelerator, i.e. one which has a single ergodic component, produces a weaker energy flow than a multi-component accelerator. Specifically, in the ergodic case the energy gain is independent of the hole size, whereas in the multi-component case the energy flow may be significantly increased by shrinking the hole size.

  5. Particle-accelerator decommissioning

    Generic considerations involved in decommissioning particle accelerators are examined. There are presently several hundred accelerators operating in the United States that can produce material containing nonnegligible residual radioactivity. Residual radioactivity after final shutdown is generally short-lived induced activity and is localized in hot spots around the beam line. The decommissioning options addressed are mothballing, entombment, dismantlement with interim storage, and dismantlement with disposal. The recycle of components or entire accelerators following dismantlement is a definite possibility and has occurred in the past. Accelerator components can be recycled either immediately at accelerator shutdown or following a period of storage, depending on the nature of induced activation. Considerations of cost, radioactive waste, and radiological health are presented for four prototypic accelerators. Prototypes considered range from small accelerators having minimal amounts of radioactive mmaterial to a very large accelerator having massive components containing nonnegligible amounts of induced activation. Archival information on past decommissionings is presented, and recommendations concerning regulations and accelerator design that will aid in the decommissioning of an accelerator are given

  6. Theoretical and numerical study of the expansion of a laser-produced plasma: high energy ion acceleration; Etude theorique et numerique de l'expansion d'un plasma cree par laser: acceleration d'ions a haute energie

    Grismayer, T

    2006-12-15

    This work is a theoretical and numerical study on the high energy ion acceleration in laser created plasma expansion. The ion beams produced on the rear side of an irradiated foil reveal some characteristics (low divergence, wide spectra) which distinguish them from the ones coming from the front side. The discovery of these beams has renewed speculation for applications such as proton-therapy or proton radiography. The ion acceleration is performed via a self-consistent electrostatic field due to the charge separation between ions and hot electrons. In the first part of this dissertation, we present the fluid theoretical model and the hybrid code which simulates the plasma expansion. The numerical simulation of a recent experience on the dynamic of the electric field by proton radiography validates the theoretical model. The second part deals with the influence of an initial ion density gradient on the acceleration efficiency. We establish a model which relates the plasma dynamic and more precisely the wave breaking of the ion flow. The numerical results which predict a strong decrease of the ion maximum energy for large gradient length are in agreement with the experimental data. The Boltzmann equilibrium for the electron assumed in the first part has been thrown back into doubt in the third part. We adopt a kinetic description for the electron. The new version of the code can measure the Boltzmann law deviation which does not strongly modify the maximum energy that can reach the ions. (author)

  7. Study of medical RI production with accelerator-based neutron sources

    The single-photon emission computed tomography (SPECT) and positron emission tomography (PET) have been widely adopted for nuclear medicine imaging to make diagnoses of body functions, identification of site of cancers, and so on. Now, almost all of medical radio isotopes are produced by nuclear reactors or charged particle accelerators. We propose a new route to produce the medical radio isotopes with accelerator-based neutron sources. In this paper, as an example, we introduce the proposed production method of 99Mo, which is the mother nuclide of 99mTc for SPECT. We determined the 100Mo(n,2n)99Mo reaction cross section to 1,415±82mb and it was consistent with the value (1,398mb) obtained from JENDL-4.0. Therefore, it indicates yields of produced RIs can be predicted with nuclear data based simulations. The simulation also can be used to design irradiation condition. In this paper some results of the simulations are also shown. (author)

  8. Removal of round off errors in the matrix exponential method for solving the heavy nuclide chain

    Many nodal codes for core simulation adopt the micro-depletion procedure for the depletion analysis. Unlike the macro-depletion procedure, the microdepletion procedure uses micro-cross sections and number densities of important nuclides to generate the macro cross section of a spatial calculational node. Therefore, it needs to solve the chain equations of the nuclides of interest to obtain their number densities. There are several methods such as the matrix exponential method (MEM) and the chain linearization method (CLM) for solving the nuclide chain equations. The former solves chain equations exactly even when the cycles that come from the alpha decay exist in the chain while the latter solves the chain approximately when the cycles exist in the chain. The former has another advantage over the latter. Many nodal codes for depletion analysis, such as MASTER, solve only the hard coded nuclide chains with the CLM. Therefore, if we want to extend the chain by adding some more nuclides to the chain, we have to modify the source code. In contrast, we can extend the chain just by modifying the input in the MEM because it is easy to implement the MEM solver for solving an arbitrary nuclide chain. In spite of these advantages of the MEM, many nodal codes adopt the chain linearization because the former has a large round off error when the flux level is very high or short lived or strong absorber nuclides exist in the chain. In this paper, we propose a new technique to remove the round off errors in the MEM and we compared the performance of the two methods

  9. Future accelerators (?)

    I describe the future accelerator facilities that are currently foreseen for electroweak scale physics, neutrino physics, and nuclear structure. I will explore the physics justification for these machines, and suggest how the case for future accelerators can be made

  10. Future accelerators (?)

    John Womersley

    2003-08-21

    I describe the future accelerator facilities that are currently foreseen for electroweak scale physics, neutrino physics, and nuclear structure. I will explore the physics justification for these machines, and suggest how the case for future accelerators can be made.

  11. SU-E-T-543: Measurement of Neutron Activation From Different High Energy Varian Linear Accelerators

    Purpose: Linear accelerators producing photons above 10 MeV may induce photonuclear reactions in high Z components of the accelerator. These liberated neutrons can then activate the structural components of the accelerator and other materials in the beam path through neutron capture reactions. The induced activity within the accelerator may contribute to additional dose to both patients and personnel. This project seeks to determine the total activity and activity per activated isotope following irradiation in different Varian accelerators at energies above 10 MeV. Methods: A Varian 21IX accelerator was used to irradiate a 30 cm × 30 cm × 20 cm solid water phantom with 15 MV x-rays. The phantom was placed at an SSD of 100 cm and at the center of a 20 cm × 20 cm field. Activation induced gamma spectra were acquired over a 5 minute interval after 1 and 15 minutes from completion of the irradiation. All measurements were made using a CANBERRA Falcon 5000 Portable HPGe detector. The majority of measurements were made in scattering geometry with the detector situated at 90° to the incident beam, 30 cm from the side of the phantom and approximately 10 cm from the top. A 5 minute background count was acquired and automatically subtracted from all subsequent measurements. Photon spectra were acquired for both open and MLC fields. Results: Based on spectral signatures, nuclides have been identified and their activities calculated for both open and MLC fields. Preliminary analyses suggest that activities from the activation products in the microcurie range. Conclusion: Activation isotopes have been identified and their relative activities determined. These activities are only gross estimates since efficiencies have not been determined for this source-detector geometry. Current efforts are focused on accurate determination of detector efficiencies using Monte Carlo calculations

  12. Accelerating Value Creation with Accelerators

    Jonsson, Eythor Ivar

    2015-01-01

    accelerator programs. Microsoft runs accelerators in seven different countries. Accelerators have grown out of the infancy stage and are now an accepted approach to develop new ventures based on cutting-edge technology like the internet of things, mobile technology, big data and virtual reality. It is also......Accelerators can help to accelerate value creation. Accelerators are short-term programs that have the objective of creating innovative and fast growing ventures. They have gained attraction as larger corporations like Microsoft, Barclays bank and Nordea bank have initiated and sponsored...

  13. Model for GCR-particle fluxes in stony meteorites and production rates of cosmogenic nuclides

    Reedy, R.C.

    1984-01-01

    A model is presented for the differential fluxes of galactic-cosmic-ray (GCR) particles with energies above 1 MeV inside any spherical stony meteorite as a function of the meteorite's radius and the sample's depth. This model is based on the Reedy-Arnold equations for the energy-dependent fluxes of GCR particles in the moon and is an extension of flux parameters that were derived for several meteorites of various sizes. This flux is used to calculate the production rates of many cosmogenic nuclides as a function of radius and depth. The peak production rates for most nuclides made by the reactions of energetic GCR particles occur near the centers of meteorites with radii of 40 to 70 g cm/sup -2/. Although the model has some limitations, it reproduces well the basic trends for the depth-dependent production of cosmogenic nuclides in stony meteorites of various radii. These production profiles agree fairly well with measurements of cosmogenic nuclides in meteorites. Some of these production profiles are different than those calculated by others. The chemical dependence of the production rates for several nuclides varies with size and depth. 25 references, 8 figures.

  14. News from the Library: The 8th edition Karlsruhe nuclide chart has been released

    CERN Library

    2012-01-01

    The 8th edition of the Karlsruhe Nuclide Chart contains new data not found in the 7th edition.   Since 1958, the well-known Karlsruhe Nuclide Chart has provided scientists with structured, valuable information on the half-lives, decay modes and energies of radioactive nuclides. The chart is used in many disciplines in physics (health physics, radiation protection, nuclear and radiochemistry, astrophysics, etc.) but also in the life and earth sciences (biology, medicine, agriculture, geology, etc.). The 8th edition of the Karlsruhe Nuclide Chart contains new data on 737 nuclides not found in the 7th edition. In total, nuclear data on 3847 experimentally observed ground states and isomers are presented. A new web-based version of this chart is in the final stages of development for use within the Nucleonica Nuclear Science Portal - a portal for which CERN has an institutional license. The chart is also available in paper format.   If you want to buy a paper version of the chart, ple...

  15. NKE 2.16, Nuclide Explorer tool for retrieving interactively detailed data on radionuclides properties

    1 - Description of program or function: The Nuclide Explorer (NKE) program is a tool for retrieving interactively detailed data on radionuclides properties. The data that can be retrieved are: a) elements information (average mass, density, neutron cross sections); b) nuclear ground/metastable states properties (half-life and decay channels percentage); c) decay alpha, beta, gamma, electron, positron radiation information (spectra and lines); d) fission products yields (for various fissionable target nuclides); e) thermal neutron cross sections and resonance integrals (capture and fission); f) fission spectrum average threshold neutron reactions cross sections for (n,p), (n,alpha), (n,2n), (n,n') and (n,gamma) reactions. Fast neutron fission has been added. It contains data on more than 3000 nuclides (approximately 3700 ground and metastable states). The data were mined from various public data bases. 2 - Methods: Users interact with the main program screen which is Segre nuclide chart to obtain detailed nuclide/element information. It contains a built-in decay calculator and filter utility. For instance users can filter data using various criteria (e.g. half-life, decay modes and particles energies)

  16. A nuclide transport model in the fractured rock medium using a continuous time markov process

    A stochastic way using continuous time Markov process is presented to model the one dimensional nuclide transport in fractured rock matrix as an extended study for previous work. A nuclide migration model by the continuous time Markov process for single planar fractured rock matrix, which is considered as a transient system where a process by which the nuclide is diffused into the rock matrix from the fracture may be on more time homogeneous, is compared with a conventional deterministic analytical solution. The primary desired quantities from a stochastic model are the expected values and variance of the state variables as a function of time. The time-dependent probability distributions of nuclides are presented for each discretized compartment of the medium given intensities of transition. Since this model is discrete in medium space, parameters which affect nuclide transport could be easily incorporated for such heterogeneous media as the fractured rock matrix and the layered porous media. Even though the model developed in this study was shown to be sensitive to the number of discretized compartment showing numerical dispersion as the number of compartments is decreased, with small compensating of dispersion coefficient, the model agrees well to analytical solution. (Author)

  17. The evaluation of the nuclides migration from Maishiagala radioactive waste repository taking into consideration the actual tritium release

    The evaluation of the nuclides migration from Maishiagala repository was performed taking into consideration the actual tritium release. The waste activity includes the activity of nuclides from the sealed containers. It was shown that the most dangerous nuclides are 3H, 36Cl and 239Pu which concentrations in the groundwater 35 m from the repository (at fence) and annual effective dose to population can exceed acceptable limits. (author)

  18. Concept for calculating dose rates from activated groundwater at accelerator sites

    Prolingheuer, N; Vanderborght, J; Schlögl, B; Nabbi, R; Moormann, R

    Licensing of particle accelerators requires the proof that the groundwater outside of the site will not be significantly contaminated by activation products formed below accelerator and target. In order to reduce the effort for this proof, a site independent simplified but conservative method is under development. The conventional approach for calculation of activation of soil and groundwater is shortly described on example of a site close to Forschungszentrum Juelich, Germany. Additionally an updated overview of a data library for partition coefficients for relevant nuclides transported in the aquifer at the site is presented. The approximate model for transport of nuclides with ground water including exemplary results on nuclide concentrations outside of the site boundary and of resulting effective doses is described. Further applications and developments are finally outlined.

  19. Plasma based accelerators

    Caldwell, Allen [Max-Planck-Institut fuer Physik, Muenchen (Germany)

    2015-05-01

    The concept of laser-induced plasma wakefields as a technique to accelerate charged particles was introduced 35 years ago as a means to go beyond the accelerating gradients possible with metallic cavities supporting radio frequency electromagnetic fields. Significant developments in laser technology have made possible the pulse intensity needed to realize this concept, and rapid progress is now underway in the realization of laser-driven plasma wakefield acceleration. It has also been realized that similar accelerating gradients can be produced by particle beams propagating in plasmas, and experimental programs have also been undertaken to study this possibility. Positive results have been achieved with electron-driven plasma wakefields, and a demonstration experiment with proton-driven wakefields is under construction at CERN. The concepts behind these different schemes and their pros and cons are described, as well as the experimental results achieved. An outlook for future practical uses of plasma based accelerators will also be given.

  20. The reactivity effects of nuclide buildup and decay during long-term fuel storage

    This paper presents the results of an analysis of spent fuel reactivity over a 100,000-year cooling time. The goal of this work was to study the changes in reactivity and to recognize which nuclides contribute to such changes. The analysis employs the use of the effective one-group cross-section data of each nuclide studied. The primary contributors to K∞ changes during long-term spent fuel storage were identified as 239Pu, 240Pu, 241Pu, 241Am, and 235U. The approach presented here can be processed simply by spreadsheet-type calculations on a personal computer after performing only one SAS2H calculation to obtain one-group cross-section data and nuclide densities

  1. The protection of radioactive nuclide and nursing management in DSA room

    Objective: To discuss the protection of radioactive nuclide and nursing management in DSA room. Methods: The clinical state of the protection of radioactive 131I nuclide and nursing management in DSA room was retrospectively summarized. Results: The standard management for the protection of radioactive nuclide in DSA room was established. The main management schemas included the management of personnel, the management of professional skills and, specialty, the management of radioactive drugs and abandoned odds and ends, preoperative health education, etc. Conclusion: The standard management can ensure that the patients get a good radionuclide therapy in DSA room, and, at the same time, the working environment can be effectively protected and the professional nursing staff can be well trained. (authors)

  2. Development of continuous monitor for multiple beta-ray nuclides in liquid radioactive waste

    Nam, Uk Won; Seon, G. I.; Kong, G. N.; Chin, H.; Park, J. H.; Yuk, I. S.; Han, W. Y. [Korea Astronomy and Space Science Institute, Taejon (Korea, Republic of)

    2001-03-15

    Continuous monitor system of multiple beta-ray nuclides was designed conceptually while keeping the optimization and the automation in mind. The conincidence MCA was designed to maintain, repair and upgrade with ease. DSP was adopted to realize hardware function using software and to miniaturize the coincidence Multi Channel Analyzer (MCA). The MCA system showed 99% background rejection rate, and was applied well to gamma-ray system using {sup 60}C0. An algorithm using least square method was developed for simultaneous radioassay of multiple beta-ray nuclides. The algorithm was tested using the simulation and was applied to experimental data. The results show that the algorithm is suitable to continous monitor system of multiple beta-ray nuclides.

  3. Reevaluation of decay energies of fission product nuclides in JNDC FP Decay Data File

    The decay data of all experimentally identified fission product nuclides included in the JNDC FP Decay Data File are reviewed in detail, since the missing of beta-transition to unobserved highly excited states in the daughter nucleus is considered to be probable in some cases even for nuclides with small Qβ. Thus the decay energies of 127 nuclides or metastable states except for 88Rb and 143La revised previously are reevaluated. The results of summation calculations based on the revised JNDC FP Decay Data File modified by the present evaluation are in much better agreement with experimentally measured decay power curves than previous ones. Especially, the discrepancy remained for cooling times from a few hundreds to about 1500 seconds is removed. And the agreement is kept within about 5 % for wide range of cooling times. (author)

  4. Fast-Neutron Activation of Long-Lived Nuclides in Natural Pb

    Guiseppe, V E; Fields, N E; Hixon, D

    2012-01-01

    We measured the production of the long-lived nuclides Bi-207, Pb-202, and Hg-194 in a sample of natural Pb due to high-energy neutron interactions using a neutron beam at the Los Alamos Neutron Science Center. The activated sample was counted by a HPGe detector to measure the amount of radioactive nuclides present. These nuclides are critical in understanding potential backgrounds in low background experiments utilizing large amounts of Pb shielding due to cosmogenic neutron interactions in the Pb while residing on the Earth's surface. By scaling the LANSCE neutron flux to a cosmic neutron flux, we measure the sea level cosmic ray production rates of 8.0 +/- 1.3 atoms/kg/day of Hg-194, 120 +/- 25 atoms/kg/day Pb-202, and 0.17 +/- 0.04 atoms/kg/day Bi-207.

  5. Measurement of activity of surfaces contaminated by beta-emitting nuclides and 55Fe

    The responses of a variety of different types of surface contamination monitoring probes to both small area and distributed sources of the β-emitting nuclides, 90Sr/90Y, 204Tl, 147Pm, 14C and 63Ni, have been measured. The responses to the low-energy X-ray emitting electron-capture nuclide, 55Fe, have also been measured. A figure of merit for the comparison of different types of probe has been derived and applied to the measured responses. The responses of a beryllium-window sodium iodide scintillation probe to 55Fe with integral and differential bias is described in detail; calculated responses to the electron-capture nuclides, 109Cd and 125I, are also included in this report. (author)

  6. Vertical transfer of several nuclides in the soil of a region

    In order to study the vertical transfer of the artificial nuclide (137Cs) and the natural nuclides (238U, 226Ra, 232Th and 40K) in the soil of a region, a number of undisturbed soil samples in points A and B of this region are collected. The specific activities of these samples are obtained by using low background multichannel anti-Compton γ spectrum microcomputer measurement and analysis system to directly measure the γ spectrum of the samples. The simulated curves showing the changes of these nuclide specific activities with the depths are described, the possible compositions of the soil in this region are speculated. Finally, the vertical transfer velocity of 137Cs suggests to be 0.6-1.2 cm/a according to two measured results. (authors)

  7. Estimate of (n, p) cross-section for unstable nuclide 53Mn

    53Mn is one of the long-lived radionuclides (decay by electron capture) having half life of 3.74x106 year, produced inside the fusion reactor, due to transmutation of stable isotopes of Stainless Steel (SS) present in the structural materials. Due to its longer half life and as primary nuclide (isotopes having percentage contribution ≥50%) it interacts with neutrons inside the reactor and give rise to different nuclear reactions depending on the neutron energy and reaction Q values. Neutrons emitted in a D-T fusion reactor (D+T → n+α+17.6 MeV) are of 14.1 MeV energy, however inside the fusion reactor the energy of the neutrons degrades due to interactions with various reactor materials resulting in a neutron spectrum with energy from eV to MeV range. From neutronics point of view, it is therefore important to study the nuclear reactions such as 53Mn(n,p), 53Mn(n,α), 53Mn(n,d) and 53Mn(n,t). The (n,p) (n,α) and (n,d) reactions can cause the production of hydrogen, helium and deuterium gases while (n,t) is important for production of tritium (3H; T½ =12.33 year) inside the fusion reactor. The (n,p) and (n,α) reactions are more critical because He/H deposit at different locations inside the reactor can degrade the integrity of the materials

  8. On a Solar Origin for the Cosmogenic Nuclide Event of 775 A.D.

    Cliver, E. W.; Tylka, A. J.; Dietrich, W. F.; Ling, A. G.

    2014-01-01

    We explore requirements for a solar particle event (SPE) and flare capable of producing the cosmogenic nuclide event of 775 A.D., and review solar circumstances at that time. A solar source for 775 would require a greater than 1 GV spectrum approximately 45 times stronger than that of the intense high-energy SPE of 1956 February 23. This implies a greater than 30 MeV proton fluence (F(sub 30)) of approximately 8 × 10(exp 10) proton cm(exp -2), approximately 10 times larger than that of the strongest 3 month interval of SPE activity in the modern era. This inferred F(sub 30) value for the 775 SPE is inconsistent with the occurrence probability distribution for greater than 30 MeV solar proton events. The best guess value for the soft X-ray classification (total energy) of an associated flare is approximately X230 (approximately 9 × 10(exp 33) erg). For comparison, the flares on 2003 November 4 and 1859 September 1 had observed/inferred values of approximately X35 (approximately 10(exp 33) erg) and approximately X45 (approximately 2 × 10(exp 33) erg), respectively. The estimated size of the source active region for a approximately 10(exp 34) erg flare is approximately 2.5 times that of the largest region yet recorded. The 775 event occurred during a period of relatively low solar activity, with a peak smoothed amplitude about half that of the second half of the 20th century. The approximately 1945-1995 interval, the most active of the last approximately 2000 yr, failed to witness a SPE comparable to that required for the proposed solar event in 775. These considerations challenge a recent suggestion that the 775 event is likely of solar origin.

  9. Radiological accidents: methodologies of radio nuclides dis incorporation

    Derived of the radioactive or nuclear material management, exists the risk that accidents can happen where people cases are presented with internal radioactive contamination, who will receive specialized medical care to accelerate the radioactive dis incorporation with the purpose of diminishing the absorbed dose and the associate biological effects. In this work treatments of radioactive dis incorporation were identified, in function of the radionuclide, radiation type, radioactive half life, biological half life, critical organ, ingestion duct and patient type. The factor time is decisive for the effectiveness of the selected treatment in the blockade stage (before the accident) or dis incorporation (after the accident); this factor is related with the radioactive and biological half lives. So to achieve dis incorporation efficiencies of more to 70%, the patient clinical treatment will begin before the first third of the biological half life of the radionuclide that generated the internal contamination. (Author)

  10. Accelerators for energy production

    A tremendous progress of accelerators for these several decades, has been motivated mainly by the research on subnuclear physics. The culmination in high energy accelerators might be SSC, 20 TeV collider in USA, probably the ultimate accelerator being built with the conventional principle. The technology cultivated and integrated for the accelerator development, can now stably offer the high power beam which could be used for the energy problems. The Inertial Confinement Fusion (ICF) with high current, 10 kA and short pulse, 20 ns heavy ion beam (HIB) of mass number ∼200, would be the most promising application of accelerators for energy production. In this scenario, the fuel containing D-T mixture, will be compressed to the high temperature, ∼10 keV and to the high density state, ∼1000 times the solid density with the pressure of ablative plasma or thermal X ray produced by bombarding of high power HIB. The efficiency, beam power/electric power for accelerator, and the repetition rate of HIB accelerators could be most suitable for the energy production. In the present paper, the outline of HIB ICF (HIF) is presented emphasizing the key issues of high current heavy ion accelerator system. (author)

  11. Cosmogenic Nuclide Budgeting of Floodplain Sediment Transfer and Examples from the Amazon Basin

    H. Wittmann; F. von Blanckenburg; P. Kubik

    2009-01-01

    Cosmogenic nuclides measured in river sediment can be used to provide basin-wide, spatially-averaged denudation rates over time scales meaningful to rock weathering and erosion itself, thus bridging the gap between long-term denudation rates from thermo-chronology and lake fills and short-term river loads [1-4]. In this study, we assess the effects of sediment deposition and storage on this method, because cosmogenic nuclides may be prone to additional irradiation or decay during long-term st...

  12. Recent developments in short-lived nuclide activation analysis and analytical efficiency

    In various applications of neutron activation analysis, wide element concentration and nuclide half-life ranges, overlapping peaks and other interferences in the gamma-spectrum and the request for isotope abundance determination as well as other special problems are encountered which led to the development of a flexible analytical system for the optimization and differentiation of the experimental conditions in order to solve properly these multiparameter problems. The new features were introduced mainly in the analysis of short-lived nuclides with high throughput capability, enhancing also the analytical efficiency and broadening the application range of neutron activation analysis. (author) 4 refs.; 6 figs

  13. Self-absorption correction in γ-ray efficiency calibration of fission gas nuclide

    In order to solve the problem of self-absorption correction in γ-ray efficiency calibration of fission gas nuclide, the parameters about source container, detector and source matrix etc.were described, and Monte-Carlo model and program of efficiency computation for HPGe detector were established according to experiment layout. The efficiency of fission gas nuclides was calculated in the different source matrices, and the corresponding self-absorption coefficients were obtained. The reliability of the model was validated by the experiment data. (authors)

  14. Investigation on natural radioactive nuclide contents of rock products in Xi'an construction materials market

    The author reports the investigation results on natural radioactive nuclide contents of rock products from Xi'an construction materials market. The products were classified according to the national standard. The results show that natural radioactive nuclide contents in sampled rock products are in normal radioactive background levels. The radio-activity ranges of 238U, 226Ra, 232Th and 40K are 2.7 - 181.8, 0.92 - 271.0, 0.63 - 148.0, 1.8 - 1245 Bq·kg-1, respectively. According to the national standard (JC 518-93), the application of some rock products must be limited

  15. Laser accelerator

    Vigil, Ricardo

    2014-01-01

    Approved for public release; distribution is unlimited In 1979,W. B. Colson and S. K. Ride proposed a new kind of electron accelerator using a uniform magnetic field in combination with a circularly-polarized laser field. A key concept is to couple the oscillating electric field to the electron’s motion so that acceleration is sustained. This dissertation investigates the performance of the proposed laser accelerator using modern high powered lasers and mag-netic fields that are significan...

  16. Physiologically acceptable finely divided radio-nuclide carrier

    The phosphorylised starch-tin II mixture used to produce a scintigraphic material carrying technetium 99 m contains 4-5% by weight of phosphate and 0.2-0.8% by weight of tin. It can easily be decomposed by the body. (DG)

  17. 潜艇艉轴及电机激振对电机基座加速度的影响%Analysis of the Acceleration Effects on Submarine's Engine Pedestal Produced by the Excitation Force from Propeller Shafts and Engines

    谭路; 纪刚

    2013-01-01

    The engine vibration is a major excitation source of submarine noise and requires substantial consideration during the structural design process. In this paper,an approach combining the finite element method with the boundary element method is proposed to calculate the underwater vibration of submarines with two different excitation sources- the propeller shaft and the engine. The acceleration effects on the submarine's engine pedestal,produced by the low frequency excitation force from the two sources men-tioned above were also investigated. The obtained numerical results were compared and analyzed at differ-ent frequencies and power values. It was seen that the acceleration effects produced by the propeller shaft was quite small and could be safely neglected when the propeller shaft excitation was one order greater in magnitude than the engine vibration force. Overall,this observation could simplify and benefit the measure-ment of engine vibration characteristics in actual submarine applications.%电机振动为潜艇噪声的重要振源,掌握其特性对于优化艇体结构设计有着重要的意义。采用结构有限元耦合流体边界元的附加质量阻尼算法,对潜艇的2种不同位置激振的工况进行水下振动计算,并对数值计算结果进行了比较和分析。从离散频率的加速度值和功率两个层面上初步讨论了低频段内艉轴激振力与电机激振力对电机基座上加速度的影响。结果表明:在艉轴激振力比电机激振力大一个数量级的情况下,艉轴激振力对电机基座加速度的影响远小于电机激振力对其的影响,因而可以忽略。在实艇航行中,当艉轴与电机激振力同时存在的情况下,确保了电机振动特征信号测量的准确性。

  18. Recycling Of Bomb Produced Cl 36

    Lazarev, V.; Blinov, A.; Huber, Th.; Kubo, F.; Nolte, E.

    The success of accelerated mass-spectrometry (AMS) has allowed the measuring of very small quantities of radioactive nuclides with the ratio to their stable isotope up to 10-14. With the help of this method the concentration of 36Cl in natural samples can be investigated. The main sources of 36Cl in the atmosphere are a) The natural production in nuclear reactions induced by the interaction of high energy cosmic rays with atmospheric Ar. b) The production by the interaction of high neutron fluxes emitted by the nuclear weapon tests with stable chlorine. c) The production in different reactors with the following release (e.g. Chernobyl accident). The analysis of 36Cl time profile in Greenland showed the fast removal of chlorine from the atmosphere so that nowadays only the natural production of 36Cl is of importance. However the measurement of 36Cl in modern precipitation revealed the significant excess of its concentration over the simulated predictions. The recycling of chlorine as an explanation of the observed discrepancy is ar- gued. The biosphere could take up a part of the fallen down bomb produced 36Cl and releases it into the troposphere in the form of CH3Cl. To check the hypothesis the experiment to collect methyl chloride from the air and to measure 36Cl was set up. The high observed ratio 36 Cl/Cl proves that the chlorine recycling really takes place. Additionally, in order to get more information about the distribution of 36Cl the measurements of its concentration in lakes with long flushing times were performed. With the help of modeling the different sources of 36Cl can be distinguished. The dominant source of 36Cl in many Alpine lakes is chlorine, released during the accident on the Chernobyl nuclear power plant.

  19. Specific gamma-ray dose constants for nuclides important to dosimetry and radiological assessment

    Tables of specific gamma-ray dose constants (the unshielded gamma-ray dose equivalent rate at 1 m from a point source) have been computed for approximately 500 nuclides important to dosimetry and radiological assessment. The half life, the mean attenuation coefficient, and thickness for a lead shield providing 95% dose equivalent attenuation are also listed

  20. Individual radiation doses from nuclides contained in a WP-cave repository for spent fuel

    The individual radiation doses to man were calculated from leakage of radionuclides from a WP-cave repository for spent nuclear fuel. This study is a part of a safety analysis of a WP-cave repository performed by SKB. It was assumed that the nuclides reach the biosphere by inflow to a well and/or a lake. Therefore calculations were performed for three different critical groups. The turnover in the biosphere and the exposure to man was modelled by a compartment model using the BIOPATH-code. The nuclides dominating the total dose were identified. These were C-14, Se-79, Sn-126, I-129, Pa-231, Th-229 and Np-237. Maximum doses were about 3E-6 Sv/year. Uncertainty analysis was carried out using the PRISM-code for the dose dominant nuclides. For all nuclides and cases the ranges of the doses are within three orders of magnitude for 90% confidence interval. The main parameters to the uncertainty in the case with outflow to a well are the volume of the well, the amount of water consumed or the migration in the soil. For the lake case major contributions to the uncertainty arise from the sedimentation, bioaccumulation in fish and the amount of consumption of fish. (authors) (33 refs.)

  1. Impact of burnable absorber Gd on nuclide composition for VVER-440 fuel (Gd-2)

    The latest version of Russian fuel VVER-440 includes burnable absorber in 6 pins. In this article is impact of burnable absorber on nuclide composition and criticality analyzed. In part 1 was analyzed whole burnup interval 0-50 MWd/kgU. In present part 2 are detailed analysis only for first cycle (burnup 0-10 MWd/kgU). (Authors)

  2. Nuclear power technology system with molten salt reactor for transuranium nuclides burning in closed fuel cycle

    A concept of nuclear power technology system with homogeneous molten salt reactors for burning and transmutation of long-lived radioactive toxic nuclides is considered in the paper. Disposition of such reactors in enterprises of fuel cycle allows to provide them with power and facilitate solution of problems with rad waste with minimal losses. (Authors)

  3. Spins and magnetic moments of rubidium and cesium nuclides far from stability

    Previous studies at ISOLDE have concerned spins and magnetic moments of neutron-deficient rubidium and cesium isotopes. Here, the main results obtained, and, in the case of cesium, new moment measurements are briefly discussed also the results from measurements on neutron-rich nuclides of rubidium and cesium. (orig./AH)

  4. Contribution of some food categories on intakes of U, Th and other nuclides

    The assessment of radiation dose in human from radioactive 232Th, 238U, 137Cs, and 90Sr are important because those nuclides are the largest contributors to committed internal doses. A market basket study was conducted to clarify the food pathways of the nuclides in Japanese subjects. Foodstuffs of 336 were purchased from markets in the vicinity of Mito-City during 1994-1995. Statistical consumption data were used for collection of the food samples. Thorium-232, 238U, and stable isotope (133Cs) in eighteen food groups were determined by inductively coupled mass spectrometry (ICP-MS). Radioisotopes (137Cs) was analyzed by γ-spectrometry. Stable strontium (88Sr) was also analyzed by inductively coupled atomic emission spectrometry (ICP-AES). Big contributors to the nuclide intakes in Japanese were as follows: 232Th fishes and shellfishes (44%) and green vegetables (11%); 238U seaweeds (50%) and fishes and shellfishes (26%); 88Sr seaweeds (53%) and fishes and shellfishes (14%); 137Cs mushrooms (17%), fishes and shell fishes (15%), milk products (11%), meats (9%), and potatoes (7%). The food categories of oil and fats, eggs and cooked meals were minor contributors in those nuclides. Dietary intake studies by using eighteen or more food categories should be effective procedure to resolve critical food and critical pathway for Japanese. Furthermore, critical pathways of radionuclides could be estimated by the analyses of stable isotopes. (author)

  5. Three-dimensional nuclide decay chain transport behavior in the deep geological disposal system

    Using a three-dimensional numerical code, B3Rch developed for nuclide transport of an arbitrary length of decay chain in the media including buffer between canister and adjacent rock in a deep geological high-level radioactive waste repository, some illustrative calculations for a case of decay chain of 234 U → 230 Th 226 Ra, which is one of the most important chain as far as the human environment is concerned, are introduced. A finite difference method utilizing the control-volume scheme is adopted assuming a linear sorption isotherm, nuclide transport due to diffusion in the buffer and the rock matrix, and advection and dispersion along thin rigid parallel fractures existing in a saturated porous rock matrix as well as diffusion through the fracture wall into the matrix. To show how visualization of nuclide behavior can be made to see the effects of buffer and rock matrix on nuclide transport in HLW repository and also to demonstrate usefulness of B3R, several cases of three-dimensional concentration isopleths associated with these disposal system barriers are plotted

  6. Mass measurement of halo nuclides and beam cooling with the mass spectrometer Mistral

    Halo nuclides are a spectacular drip-line phenomenon and their description pushes nuclear theories to their limits. The most critical input parameter is the nuclear binding energy; a quantity that requires excellent measurement precision, since the two-neutron separation energy is small at the drip-line by definition. Moreover halo nuclides are typically very short-lived. Thus, a high accuracy instrument using a quick method of measurement is necessary. MISTRAL is such an instrument; it is a radiofrequency transmission mass spectrometer located at ISOLDE/CERN. In July 2003 we measured the mass of the Li11, a two-neutron halo nuclide. Our measurement improves the precision by a factor 6, with an error of 5 keV. Moreover the measurement gives a two-neutron separation energy 20% higher than the previous value. This measurement has an impact on the radius of the nucleus, and on the state of the two valence neutrons. At the same time, a measurement of the Be11 was performed with an uncertainty of 4 keV, in excellent agreement with previous measurements. In order to measure the mass of the two-neutron halo nuclide Be14, an ion beam cooling system is presently under development which will increase the sensitivity of the spectrometer. The second part of this work presents the development of this beam cooler using a gas-filled Paul trap. (author)

  7. LIBO accelerates

    2002-01-01

    The prototype module of LIBO, a linear accelerator project designed for cancer therapy, has passed its first proton-beam acceleration test. In parallel a new version - LIBO-30 - is being developed, which promises to open up even more interesting avenues.

  8. Induction accelerators

    Takayama, Ken

    2011-01-01

    A broad class of accelerators rests on the induction principle whereby the accelerating electrical fields are generated by time-varying magnetic fluxes. Particularly suitable for the transport of bright and high-intensity beams of electrons, protons or heavy ions in any geometry (linear or circular) the research and development of induction accelerators is a thriving subfield of accelerator physics. This text is the first comprehensive account of both the fundamentals and the state of the art about the modern conceptual design and implementation of such devices. Accordingly, the first part of the book is devoted to the essential features of and key technologies used for induction accelerators at a level suitable for postgraduate students and newcomers to the field. Subsequent chapters deal with more specialized and advanced topics.

  9. Measurement of induced radioactivities for the evaluation of internal exposure at high energy accelerator facilities

    At high-intense and high energy accelerator facilities, accelerator components are exposed to primary and/or secondary high energy particles during machine operation. As a result, these become radioactive and the radioactivities are accumulated with operation time. When workers engage in maintenance work such as cutting, welding, etc. in the areas with residual activities. These become a source of internal exposure through the inhalation of radioactive airbornes as well as a source of external exposure. The estimation of external doses to workers is relatively easy by directly measuring the radiation fields by pertinent radiation counters. While the internal dose depends very much on the kinds of radioactive nuclides and their concentrations in air. In a routine survey for internal dose evaluation, airborne activities are filtered and their activities on the filter are measured with a GM counter with an automatic sample changer at KEK (the High Energy Accelerator Research Organization). Ordinarily many filter samples have to be measured with a relatively short counting time, so this gross beta counting is a practical way in a routine procedure. In order to evaluate the internal dose from these countings, it is necessary to examine precisely the kinds of radioactivities and their concentrations collected on the filters by a Ge semiconductor detector, and the correlation between the gross beta counting and the actual dose has to be made clear in advance. However, kinds of radioactivities and their concentrations depend very much on production rates of individual nuclides and time variations after beam-off. First, in order to elucidate the production rates of individual nuclides and their concentrations after beam-off, metal samples of Al, Fe, Cu, Steel, etc., which are principal materials used in accelerator facilities, were irradiated at various places in the tunnel of KEK-500MeV and 12GeV proton synchrotrons. By using these irradiated samples, we examined

  10. The miniature accelerator

    Antonella Del Rosso

    2015-01-01

    The image that most people have of CERN is of its enormous accelerators and their capacity to accelerate particles to extremely high energies. But thanks to some cutting-edge studies on beam dynamics and radiofrequency technology, along with innovative construction techniques, teams at CERN have now created the first module of a brand-new accelerator, which will be just 2 metres long. The potential uses of this miniature accelerator will include deployment in hospitals for the production of medical isotopes and the treatment of cancer. It’s a real David-and-Goliath story.   Serge Mathot, in charge of the construction of the "mini-RFQ", pictured with the first of the four modules that will make up the miniature accelerator. The miniature accelerator consists of a radiofrequency quadrupole (RFQ), a component found at the start of all proton accelerator chains around the world, from the smallest to the largest. The LHC is designed to produce very high-intensity beams ...

  11. Collective ion acceleration

    Progress achieved in the understanding and development of collective ion acceleration is presented. Extensive analytic and computational studies of slow cyclotron wave growth on an electron beam in a helix amplifier were performed. Research included precise determination of linear coupling between beam and helix, suppression of undesired transients and end effects, and two-dimensional simulations of wave growth in physically realizable systems. Electrostatic well depths produced exceed requirements for the Autoresonant Ion Acceleration feasibility experiment. Acceleration of test ions to modest energies in the troughs of such waves was also demonstrated. Smaller efforts were devoted to alternative acceleration mechanisms. Langmuir wave phase velocity in Converging Guide Acceleration was calculated as a function of the ratio of electron beam current to space-charge limiting current. A new collective acceleration approach, in which cyclotron wave phase velocity is varied by modulation of electron beam voltage, is proposed. Acceleration by traveling Virtual Cathode or Localized Pinch was considered, but appears less promising. In support of this research, fundamental investigations of beam propagation in evacuated waveguides, of nonneutral beam linear eigenmodes, and of beam stability were carried out. Several computer programs were developed or enhanced. Plans for future work are discussed

  12. Collective ion acceleration

    Godfrey, B.B.; Faehl, R.J.; Newberger, B.S.; Shanahan, W.R.; Thode, L.E.

    1977-01-01

    Progress achieved in the understanding and development of collective ion acceleration is presented. Extensive analytic and computational studies of slow cyclotron wave growth on an electron beam in a helix amplifier were performed. Research included precise determination of linear coupling between beam and helix, suppression of undesired transients and end effects, and two-dimensional simulations of wave growth in physically realizable systems. Electrostatic well depths produced exceed requirements for the Autoresonant Ion Acceleration feasibility experiment. Acceleration of test ions to modest energies in the troughs of such waves was also demonstrated. Smaller efforts were devoted to alternative acceleration mechanisms. Langmuir wave phase velocity in Converging Guide Acceleration was calculated as a function of the ratio of electron beam current to space-charge limiting current. A new collective acceleration approach, in which cyclotron wave phase velocity is varied by modulation of electron beam voltage, is proposed. Acceleration by traveling Virtual Cathode or Localized Pinch was considered, but appears less promising. In support of this research, fundamental investigations of beam propagation in evacuated waveguides, of nonneutral beam linear eigenmodes, and of beam stability were carried out. Several computer programs were developed or enhanced. Plans for future work are discussed.

  13. Effectiveness examination of requirements shown in interim report about clearance of solid waste contaminated by only short half-life nuclide

    When radiation facility for various unsealed radioisotopes intends to execute clearance of solid waste contaminated by only short half-life nuclide, a necessary strategy to prevent from contamination of long half-life nuclide has been shown in technical examination interim. We established our radiation facility as a model for classification management of nuclide according to length of half-life and examined the effectiveness of the classification management of the interim report as index nuclides, tritium and Phosphorus-32, based on the example of our classification management of the nuclide in facilities. In this report it was found that the classification management of the nuclide by half-life prevented effectively long half-life nuclide from mixing with the solid waste contaminated by only short half-life nuclide. (author)

  14. Laser plasma accelerators

    Malka, V.

    2012-01-01

    Research activities on laser plasma accelerators are paved by many significant breakthroughs. This review article provides an opportunity to show the incredible evolution of this field of research which has, in record time, allowed physicists to produce high quality electron beams at the GeV level using compact laser systems. I will show the scientific path that led us to explore different injection schemes and to produce stable, high peak current and high quality electron beams with control ...

  15. Accelerators in the sky

    The author surveys the large body of evidence showing that there are very efficient mechanisms capable of accelerating particles to high energies under very different astrophysical conditions. The circumstances whereby huge amounts of relativistic and ultrarelativistic particles such as one finds in a) cosmic rays, b) supernova remnants and c) radio galaxies and quasars are produced are considered. (Auth.)

  16. Collective accelerator for electron colliders

    Briggs, R.J.

    1985-05-13

    A recent concept for collective acceleration and focusing of a high energy electron bunch is discussed, in the context of its possible applicability to large linear colliders in the TeV range. The scheme can be considered to be a member of the general class of two-beam accelerators, where a high current, low voltage beam produces the acceleration fields for a trailing high energy bunch.

  17. Accelerator mass spectrometry: state of the art

    Tuniz, C. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia)

    1996-12-31

    Accelerator Mass Spectrometry (AMS) is the analytical technique of choice for the detection of long-lived radionuclides which cannot be practically analysed with decay counting or conventional mass spectrometry. The main use of AMS has been in the analysis of radiocarbon and other cosmogenic radionuclides for archaeological, geological and environmental applications. In addition, AMS has been recently applied in biomedicine to study exposure of human tissues to chemicals and biomolecules at attomole levels. There is also a world-wide effort to analyse rare nuclides of heavier masses, such as long-lived actinides, with important applications in safeguards and nuclear waste disposal. The use of AMS is limited by the expensive accelerator technology required and there are several attempts to develop smaller and cheaper AMS spectrometers. 5 refs.

  18. Scaling in situ cosmogenic nuclide production rates using analytical approximations to atmospheric cosmic-ray fluxes

    Lifton, Nathaniel; Sato, Tatsuhiko; Dunai, Tibor J.

    2014-01-01

    Several models have been proposed for scaling in situ cosmogenic nuclide production rates from the relatively few sites where they have been measured to other sites of interest. Two main types of models are recognized: (1) those based on data from nuclear disintegrations in photographic emulsions combined with various neutron detectors, and (2) those based largely on neutron monitor data. However, stubborn discrepancies between these model types have led to frequent confusion when calculating surface exposure ages from production rates derived from the models. To help resolve these discrepancies and identify the sources of potential biases in each model, we have developed a new scaling model based on analytical approximations to modeled fluxes of the main atmospheric cosmic-ray particles responsible for in situ cosmogenic nuclide production. Both the analytical formulations and the Monte Carlo model fluxes on which they are based agree well with measured atmospheric fluxes of neutrons, protons, and muons, indicating they can serve as a robust estimate of the atmospheric cosmic-ray flux based on first principles. We are also using updated records for quantifying temporal and spatial variability in geomagnetic and solar modulation effects on the fluxes. A key advantage of this new model (herein termed LSD) over previous Monte Carlo models of cosmogenic nuclide production is that it allows for faster estimation of scaling factors based on time-varying geomagnetic and solar inputs. Comparing scaling predictions derived from the LSD model with those of previously published models suggest potential sources of bias in the latter can be largely attributed to two factors: different energy responses of the secondary neutron detectors used in developing the models, and different geomagnetic parameterizations. Given that the LSD model generates flux spectra for each cosmic-ray particle of interest, it is also relatively straightforward to generate nuclide-specific scaling

  19. Preliminary design of a gas-cooled accelerator driven system demonstrator

    At the present time, nuclear power appears to be the best solution for producing a large amount of electricity from both economical and ecological viewpoints, provided that acceptable answers to the nuclear waste concern are found. In France, this is the subject of the law 91-1381 (December 30th , 1991). The transmutation of most of the long-lived radioactive wastes is a promising solution which could play a substantial role for the safety of the fuel cycle. Sub-critical Accelerator Driven System (ADS), coupling an ion accelerator and a sub-critical reactor, seems to have a high capacity for the fission of minor actinides and transmutation of long life fission products. The practicality on an industrial scale of partitioning and transmutation through ADS for reducing the amount of long life radio-nuclides has to be evaluated. It was recognised that the most efficient way, in terms of cost and planning, to conclusively assess the potential and the feasibility of a full scale industrial programme on ADS was to design and operate an ADS Demonstrator. The main ADS DF characteristics, defined within a joint working group, and reactor design features are described and justified. Then, main issues which call for research and development support are identified. (authors)

  20. Temporal and latitudinal cosmogenic nuclide-derived denudation rates from European river terraces

    Schaller, Mirjam; Ehlers, Todd A.

    2014-05-01

    Denudation of the Earth surface is sensitive to changes in tectonics, climate, and biotic activity. The determination of these denudation rates over space and time has proven difficult. Cosmogenic nuclide concentrations in active river sediment and river terrace deposits contain information about catchment-wide denudation rates and paleo-denudation rates, respectively. In this study, temporal and spatial variations in denudation across Europe are investigated as a function of Quaternary climate change. We test the hypothesis that Quaternary climate change impacted catchment denudation rates between glacial and interglacial cycles and during late Cenozoic global cooling. Furthermore, the latitudinal dependence and perhaps the spatially and temporally asynchronous behavior of catchments due to the effect of climate change on denudation are considered. Methods used include quantification of paleo-denudation rates from in situ-produced cosmogenic 10Be and 26Al measured in river terraces determined from catchments in southern and northern Spain (Guadalquivir and Esla, respectively), central France (Allier and Loire), and the Czech Republic (Vltava). These five catchments span 12 degrees latitude and provide a rich temporal record of denudation rates. Results from work in progress indicate that modern denudation rates (over timescales of ~20 kyr) in the Guadalquivir range between 34 to 42 mm/kyr. In the upper course of the Esla denudation rates are 50 mm/kyr and 30 mm/kyr in the lower course of the river system. For the Allier, denudation rates recalculated from measurements by Schaller et al., (2001) are around 40 mm/kyr, The denudation rates of the Vltava and the Elbe are around 30 mm/kyr with the Elbe at 38 mm/kyr. All denudation rates of the four catchments studied are very similar despite the different latitudinal and present day climatic settings. Given these similarities in denudation rates so far suggest that modern catchment denudation is relatively insensitive

  1. Uranium and thorium nuclides series determined in medicinal plants commonly used in Brazil

    Silva, P.; Francisconi, L.; Damatto, S. [IPEN/CNEN-SP, Sao Paulo (Brazil)

    2014-07-01

    In recent years the study of medicinal plants has become the focus of ever more extensive research all over the world due to their diversity and potential as source of medicinal products. According to the World Health Organization approximately 80% of world population makes use of medicinal herbs due to their believed therapeutic action. Besides being used as medicine, medicinal plants are also largely used as dietary supplements. The presence of radionuclides in plants constitutes one of the main pathways for their transfer to man. The amount of radioactive nuclides from U and Th series in edible vegetables are relatively well known since they have been the main concern of research conducted worldwide. Medicinal plants, on the other hand, have been neglected in these studies, possibly because the ingestion of radioactive material through their consumption has not been recognized or was considered insignificant. The objective of the present study was to determine the content of natural radionuclides from {sup 238}U and {sup 232}Th series in 25 species of medicinal plants used in Brazil, both as medicine and as dietary supplement. The medicinal plant samples were obtained in specialized pharmacies and drugstores. The raw plant and their extracts, produced as recommended by the National Agency for Sanitary Vigilance, were analyzed by Instrumental Neutron Activation Analyses for the determination of U and Th and by Total Alpha and Beta Counting after Radiochemical Separation for determination of {sup 226}Ra, {sup 228}Ra and {sup 210}Pb. In the raw plants the activity concentrations varied from 0,08 Bq kg{sup -1} to 8,0 Bq kg{sup -1} for thorium, from < LID to 22 Bq kg{sup -1} for uranium, from 1,8 Bq kg{sup -1} to 12 Bq kg{sup -1} for {sup 226}Ra, from 33 Bq kg{sup -1} to 74 Bq kg{sup -1} for {sup 228}Ra and from 10 Bq kg{sup -1} to 120 Bq kg{sup -1} for {sup 210}Pb. In the extracts, the activity concentrations varied from 9 mBq kg{sup -1} to 137 mBq kg{sup -1} for Th

  2. Uranium and thorium nuclides series determined in medicinal plants commonly used in Brazil

    In recent years the study of medicinal plants has become the focus of ever more extensive research all over the world due to their diversity and potential as source of medicinal products. According to the World Health Organization approximately 80% of world population makes use of medicinal herbs due to their believed therapeutic action. Besides being used as medicine, medicinal plants are also largely used as dietary supplements. The presence of radionuclides in plants constitutes one of the main pathways for their transfer to man. The amount of radioactive nuclides from U and Th series in edible vegetables are relatively well known since they have been the main concern of research conducted worldwide. Medicinal plants, on the other hand, have been neglected in these studies, possibly because the ingestion of radioactive material through their consumption has not been recognized or was considered insignificant. The objective of the present study was to determine the content of natural radionuclides from 238U and 232Th series in 25 species of medicinal plants used in Brazil, both as medicine and as dietary supplement. The medicinal plant samples were obtained in specialized pharmacies and drugstores. The raw plant and their extracts, produced as recommended by the National Agency for Sanitary Vigilance, were analyzed by Instrumental Neutron Activation Analyses for the determination of U and Th and by Total Alpha and Beta Counting after Radiochemical Separation for determination of 226Ra, 228Ra and 210Pb. In the raw plants the activity concentrations varied from 0,08 Bq kg-1 to 8,0 Bq kg-1 for thorium, from -1 for uranium, from 1,8 Bq kg-1 to 12 Bq kg-1 for 226Ra, from 33 Bq kg-1 to 74 Bq kg-1 for 228Ra and from 10 Bq kg-1 to 120 Bq kg-1 for 210Pb. In the extracts, the activity concentrations varied from 9 mBq kg-1 to 137 mBq kg-1 for Th and 145 mBq kg-1 to 580 mBq kg-1 for U. Document available in abstract form only. (authors)

  3. Relativistic heavy ion accelerators

    There is a growing interest in the scientific community in the use of accelerators to produce relativistic heavy ion beams for a number of purposes. It now appears that relativistic heavy ion collisions may provide an opportunity to study nuclear matter far from equilibrium density, pressure, and temperature. Heavy ion beams can also be used as simulated cosmic rays for astrophysical research and in planning space probes. At present the only relativistic heavy ion accelerator is the Belvalac at LBL. It has been devoted to this use since 1974. The operating experience and capabilities of this machine are reviewed as well as present and planned experimental programs. Designs of accelerators for relativistic heavy ions are discussed. A number of considerations will cause a machine to differ from a proton machine if optimally designed for heavy ion acceleration. A possible set of parameters is presented for an accelerator to produce intense beams of mass 10 to 200 ions, at energies up to 10 GeV/amu

  4. Preliminary Cosmogenic Nuclide Chronology of Late Pleistocene Missoula Floods

    Balbas, A.; Clark, J.; Clark, P. U.; Caffey, M. W.; Woodruff, T. E.; Baker, V. R.

    2014-12-01

    The Missoula floods had the largest known peak flood discharges of fresh water known from the geologic record. Multiple floods are believed to have originated from the failure of the Purcell trench ice lobe, which dammed glacial Lake Missoula. The flood waters traveled westward creating the Channeled Scabland region, a spectacular complex of anastomosing channels, coulees, cataracts, loess islands, rock basins, broad gravel deposits, and immense gravel bars in east-central Washington State. Several important questions about the Missoula floods and the formation of the Channeled Scabland remain, primarily due to the few geochronological constraints on their timing. Attempts to date the duration of the multiple floods have produced a wide range of ages (13-19 ka from land deposits and 13-31 ka from marine cores), but few of these directly constrain the age of the major flood landscape elements. Here we present 14 new in situ cosmogenic 10Be ages from quartz-bearing boulders deposited at four sites in eastern Washington. Wallula Gap is a narrow constriction along the Columbia River between Oregon and Washington. Hydraulic damming of floodwater at Wallula Gap created glacial Lake Lewis. Surface exposure ages on large boulders found at over 300 m elevation above the river at this site will date the largest flood events. The Wenatchee region represents the most northwestern area influenced by flooding. Dates from this area will determine when flooding occurred after the retreat of the Okanogan lobe. We sampled boulders from the lower Pangborn Bar, ice-rafted boulders north of Wenatchee, and boulders from a flood bar on the Columbia River north of Wenatchee. A boulder from the Mattawa Fan was sampled to assess the last time a megaflood came through the Sentinel Gap. Finally, in order to constrain the last debris dam failure at the southern end of the Upper Grand Coulee, we sampled flood boulders deposited on the Ephrata Fan.

  5. Multimegawatt cyclotron autoresonance accelerator

    Means are discussed for generation of high-quality multimegawatt gyrating electron beams using rf gyroresonant acceleration. TE111-mode cylindrical cavities in a uniform axial magnetic field have been employed for beam acceleration since 1968; such beams have more recently been employed for generation of radiation at harmonics of the gyration frequency. Use of a TE11-mode waveguide for acceleration, rather than a cavity, is discussed. It is shown that the applied magnetic field and group velocity axial tapers allow resonance to be maintained along a waveguide, but that this is impractical in a cavity. In consequence, a waveguide cyclotron autoresonance accelerator (CARA) can operate with near-100% efficiency in power transfer from rf source to beam, while cavity accelerators will, in practice, have efficiency values limited to about 40%. CARA experiments are described in which an injected beam of up to 25 A, 95 kV has had up to 7.2 MW of rf power added, with efficiencies of up to 96%. Such levels of efficiency are higher than observed previously in any fast-wave interaction, and are competitive with efficiency values in industrial linear accelerators. Scaling arguments suggest that good quality gyrating megavolt beams with peak and average powers of 100 MW and 100 kW can be produced using an advanced CARA, with applications in the generation of high-power microwaves and for possible remediation of flue gas pollutants. copyright 1996 American Institute of Physics

  6. APT accelerator technology

    The proposed accelerator production of tritium (APT) project requires an accelerator that provides a cw proton beam of 100 m A at 1300 MeV. Since the majority of the technical risk of a high-current cw (continuous-wave, 100% DF) accelerator resides in the low-energy section, Los Alamos is building a 20 MeV duplicate of the accelerator front end to confirm design codes, beam performance, and demonstrate operational reliability. We report on design details of this low-energy demonstration accelerator (LEDA) and discuss the integrated design of the full accelerator for the APT plant. LEDA's proton injector is under test and has produced more than 130 mA at 75 keV. Fabrication is proceeding on a 6.7- MeV, 8-meter-long RFQ, and detailed design is underway on coupled-cavity drift-tube linac (CCDTL) structures. In addition, detailed design and technology experiments are underway on medium-beta superconducting cavities to assess the feasibility of replacing the conventional (room-temperature copper) high-energy linac with a linac made of niobium superconducting RF cavities. (author)

  7. Theoretical calculation of decay data of short-lived nuclides for JNDC FP decay data file

    It is one of unique features of the JNDC FP Decay Data File that theoretical values of E-bar sub(β) and E-bar sub(γ), average beta- and gamma-ray energies, are fully adopted for short-lived nuclides. Here, details of the theoretical estimation method of E-bar sub(β) and E-bar sub(γ) based on 'gross theory' of beta-decay are described and the numerical tables of the estimated decay data for short-lived nuclides are presented. Further, discussion is made for justification of adoption of the theoretical values instead of values derived from decay schemes from the viewpoint of the energy profile of the beta-strength function. (author)

  8. Determination of Concentrations of Radioactive Nuclides in Soil Samples using Gamma Ray Spectroscopy

    Adil, Arsalan; Weaver, Joshua

    2015-10-01

    A hyper-pure Germanium detector system was used to determine the contents and concentrations of various nuclides in soil samples collected from different parts of the United States. These include areas in close proximity to nuclear power plants, areas susceptible to nuclear fallout from weapons testing from the pre Comprehensive Nuclear Test Ban Treaty (CTBT) period, and areas vulnerable to fallout from Fukushima from the west coast. The concentrations of naturally occurring nuclides in the 238U, 232Th, and 40K decay chains as well as that of synthetic isotopes of 137Cs and 60Co were measured with the aid of Genie-2000 and Radware (gf3m). An efficiency curve was obtained by designing a simulation and compared with standard sources. The research, now in its next stage, aims to do the same in samples from Karachi (Pakistan) which is home to three nuclear power plant projects but has no available baseline radioactivity measurements. University of Richmond.

  9. Retention of simulated fallout nuclides in agricultural crops. 1. Experiments on leys

    Eriksson, Aake; Rosen, K.; Haak, E

    1998-12-31

    Experiments with artificial wet depositions of {sup 134}Cs and {sup 85}Sr during the growth period were carried out. The studies are complementary to the experiences after the Chernobyl fallout. The aim was to get a description of the relative transfer to the harvest products of new clover-grass leys and old grass leys after initial depositions of tracer nuclides at different times during the growth period. The reduction in transfer with time, from deposition to sampling, depends partly on dilution by growth and partly on fall-off to the ground. The reduction half-time for the nuclide content showed a range 10 - 14 days. The data obtained in the experiments can extend the basis for prediction of the consequences of fallout events at different times to new as well as to old leys in the field 8 refs, 18 figs, 12 tabs

  10. Production, study and use of short-lived nuclides in pure and applied nuclear research

    The thesis which is based on 17 published papers, reports on the on-line performance of the fast radiochemical separation system SISAK, technical devlopment in the preparation of sources for beta-particles and neutrons, and on important SISAK system improvements concerning liquid hold-up time. It further reports on the development of new production targets at ISOLDE for 600 MeV proton and 910 MeV 3He-particle irradiations, on tests with a heavy ion beam of 1 GeV 12C-particles, and on the present availability of mass-separated beams of the halogen elements through new ion source development. Some results from nuclear spectroscopic studies of nuclides in selected mass regions when using such new or improved techniques are given. Examples of techniques for practical application of short-lived nuclides in radiochemical analysis and for radiochemical production for medical purposes are presented

  11. High Accuracy mass Measurement of the very Short-Lived Halo Nuclide $^{11}$Li

    Le scornet, G

    2002-01-01

    The archetypal halo nuclide $^{11}$Li has now attracted a wealth of experimental and theoretical attention. The most outstanding property of this nuclide, its extended radius that makes it as big as $^{48}$Ca, is highly dependent on the binding energy of the two neutrons forming the halo. New generation experiments using radioactive beams with elastic proton scattering, knock-out and transfer reactions, together with $\\textit{ab initio}$ calculations require the tightening of the constraint on the binding energy. Good metrology also requires confirmation of the sole existing precision result to guard against a possible systematic deviation (or mistake). We propose a high accuracy mass determintation of $^{11}$Li, a particularly challenging task due to its very short half-life of 8.6 ms, but one perfectly suiting the MISTRAL spectrometer, now commissioned at ISOLDE. We request 15 shifts of beam time.

  12. Mass mapping of a new area of neutron-deficient suburanium nuclides

    Novikov, Y N; Bosch, F; Falch, M; Geissel, H; Hausmann, M; Kerscher, T; Klepper, O; Kluge, H J; Kozhuharov, C; Litvinov, Y A; Löbner, K E G; Münzenberg, G; Patyk, Z; Radon, T; Scheidenberger, C; Wapstra, A H; Wollnik, H

    2002-01-01

    The masses of 64 short-lived neutron-deficient nuclides covering the element range from tungsten to uranium have been obtained for the first time. They have been evaluated by combining directly measured masses from Schottky mass spectrometry with linked experimental Q-values in alpha-decay chains. Based on these new mass data we have determined the one-proton and two-proton drip-lines as well as the size of the 'littoral shallow' of the sea of instability. No evidence of a Thomas-Ehrman shift has been found in the region of the investigated heavy nuclides. A peculiar behavior of two-proton separation energies has been observed in the lead region. The predictive power of various mass models is investigated.

  13. Sequentially pulsed traveling wave accelerator

    Caporaso, George J.; Nelson, Scott D.; Poole, Brian R.

    2009-08-18

    A sequentially pulsed traveling wave compact accelerator having two or more pulse forming lines each with a switch for producing a short acceleration pulse along a short length of a beam tube, and a trigger mechanism for sequentially triggering the switches so that a traveling axial electric field is produced along the beam tube in synchronism with an axially traversing pulsed beam of charged particles to serially impart energy to the particle beam.

  14. Nuclide transport models for HLW repository safety assessment in Finland, Japan, Sweden, and Canada

    Disposal and design concepts in such countries as Sweden, Finland, Canada and Japan which have already published safety assessment reports for the HLW repositories have been reviewed mainly in view of nuclide transport models used in their assessment. This kind of review would be very helpful in doing similar research in Korea where research program regarding HLW has been just started. (author). 44 refs., 2 tabs., 30 figs

  15. Nuclide transport models for HLW repository safety assessment in Finland, Japan, Sweden, and Canada

    Lee, Young Myoung; Kang, Chul Hyung; Hwang, Yong Soo; Choi, Jong Won; Kim, Sung Gi; Koh, Won Il

    1997-10-01

    Disposal and design concepts in such countries as Sweden, Finland, Canada and Japan which have already published safety assessment reports for the HLW repositories have been reviewed mainly in view of nuclide transport models used in their assessment. This kind of review would be very helpful in doing similar research in Korea where research program regarding HLW has been just started. (author). 44 refs., 2 tabs., 30 figs

  16. Four shells atomic model to computer the counting efficiency of electron-capture nuclides

    The present paper develops a four-shells atomic model in order to obtain the efficiency of detection in liquid scintillation courting, Mathematical expressions are given to calculate the probabilities of the 229 different atomic rearrangements so as the corresponding effective energies. This new model will permit the study of the influence of the different parameters upon the counting efficiency for nuclides of high atomic number. (Author) 7 refs

  17. Three L-subshells atomic model to compute counting efficiency of electron-capture nuclides

    The present paper develops a three L-subshell a and K, M-a hells atomic model in order to obtain the counting efficiency in liquid scintillation counting. Mathematical expressions are given to calculate the probabilities of 264 different atomic rearrangement way so as the corresponding effective energies. This new model will permit to test the influence of the different atomic and nuclear parameters upon the counting efficiency nuclides of low and medium atomic number decaying by electron capture. (Author) 8 refs

  18. Probabilities and energies to obtain the counting efficiency of electron-capture nuclides, KLMN model

    An intelligent computer program has been developed to obtain the mathematical formulae to compute the probabilities and reduced energies of the different atomic rearrangement pathways following electron-capture decay. Creation and annihilation operators for Auger and X processes have been introduced. Taking into account the symmetries associated with each process, 262 different pathways were obtained. This model allows us to obtain the influence of the M-electron-capture in the counting efficiency when the atomic number of the nuclide is high

  19. Total and spontaneous fission half-lives of the uranium and plutonium nuclides

    The total half-life and the half-life for spontaneous fission are evaluated for the various long-lived nuclides of interest. Recommended values are presented for 232U, 233U, 234U, 235U, 236U, 238U, 236Pu, 238Pu, 239Pu, 240Pu, 241Pu, 242Pu, and 244Pu. The uncertainties are provided at the 95% confidence limit for each of the recommended values

  20. Uranium and thorium series nuclides in river sediments and river water

    Large volume suspended sediment samples were taken from Rio Grande, Mississippi and Suwannee Rivers. These rivers drain arid, moderate and subtropical regions, respectively. The samples were taken to provide enough material to use for chemical fractionation leaching studies of the relationship between Pu and other nuclides with various components of the sediment. This work is still in progress and is described in detail in a separate section of the progress report

  1. Investigation on the nuclear track techniques for the screening of the fissile nuclides in swipe samples

    Nuclear track techniques were investigated for the screening of fissile nuclides in swipe samples. The characteristics of fission and alpha track analysis for the uranium particles were investigated in this study. The estimation of 235U enrichment for the uranium particles was performed by the fission track analysis. After identifying the uranium particles with fission track analysis in swipe samples, the 235U enrichment of the uranium particles was measured by thermal ionization mass spectrometry (TIMS).

  2. Interactive information system on the nuclear physics properties of nuclides and radioactive decay chains

    A brief review is given of a computerized information system on the nuclear physics properties of nuclides and radioactive decay chains. The main difference between the system presented here and those already in existence is that these evaluated databases of nuclear physics constants are linked to a set of programs, thus enabling analysis of a wide range of problems regarding various nuclear physics applications. (author)

  3. Interactive information system on the nuclear physics properties of nuclides and radioactive decay chains

    Plyaskin, V.I.; Kosilov, R.A. [Institute of Nuclear Power Engineering, Obninsk (Russian Federation); Manturov, G.N. [Russian Federation National Research Centre - Institute for Physics and Power Engineering, Obninsk (Russian Federation)

    2002-08-01

    A brief review is given of a computerized information system on the nuclear physics properties of nuclides and radioactive decay chains. The main difference between the system presented here and those already in existence is that these evaluated databases of nuclear physics constants are linked to a set of programs, thus enabling analysis of a wide range of problems regarding various nuclear physics applications. (author)

  4. Is it possible to quantify pebble abrasion and velocity in rivers using terrestrial cosmogenic nuclides ?

    Carretier, Sébastien; Regard, V.

    2011-01-01

    Attrition rates and mean transport velocities of coarse fluvial sediments averaged over long periods of time (>> 100 a) are yet to be fully quantified. A knowledge of long-term transport rates would allow us to predict the response of fluvial systems to changes in external conditions, while determining clast attrition rates would improve our understanding of fluvial abrasion processes. The concentration of terrestrial cosmogenic nuclides (TCNs) in boulders can be modified during river transpo...

  5. Nuclide Inventory Calculation Using MCNPX for Wolsung Unit 1 Reactor Decommissioning

    Rabir, Mohamad Hairie; Noh, Kyoung Ho; Hah, Chang Joo [KEPCO International Nuclear Graduate School, Daejeon (Korea, Republic of)

    2014-05-15

    The CINDER90 computation process involves utilizing linear Markovian chains to determine the time dependent nuclide densities. The CINDER90 depletion algorithm is implemented the MCNPX code package. The coupled depletion process involves a Monte-Carlo steady-state reaction rate calculation linked to a deterministic depletion calculation. The process is shown in Fig.1. MCNPX runs a steady state calculation to determine the system eigenvalue collision densities, recoverable energies from fission and neutrons per fission events. In order to generate number densities for the next time step, the CINDER90 code takes the MCNPX generated values and performs a depletion calculation. MCNPX then takes the new number densities and caries out a new steady-stated calculation. The process repeats itself until the final time step. This paper describe the preliminary source term and nuclide inventory calculation of Candu single fuel channel using MCNPX, as a part of the activities to support the equilibrium core model development and decommissioning evaluation process of a Candu reactor. The aim of this study was to apply the MCNPX code for source term and nuclide inventory calculation of Candu single fuel channel. Nuclide inventories as a function of burnup will be used to model an equilibrium core for Candu reactor. The core lifetime neutron fluence obtained from the model is used to estimate radioactivity at the stage of decommisioning. In general, as expected, the actinides and fission products build up increase with increasing burnup. Despite the fact that the MCNPX code is still in development we can conclude that the code is capable of obtaining relevant results in burnup and source term calculation. It is recommended that in the future work, the calculation has to be verified on the basis of experimental data or comparison with other codes.

  6. Nuclide analysis at domestic Nuclear Power Plant with CZT Detector during the overhaul

    AEP (American Electric Power) also introduced another type CZT detector to perform source term monitoring and they had announced the results through the ISOE (Information System on Occupational Exposure). A CZT semiconductor detector is good to monitor source terms at a NPP in that it is possible to make a portable type because it does not need any cooling system at room temperature and it has good energy resolution. To follow up global atmosphere, KHNP (Korea Hydro and Nuclear Power) has been trying to use CZT monitoring system at a domestic NPP. This study shows a result of the kinds of nuclides between Before H2O2 and After Clean-Up process for primary reactor coolant system nearby a steam generator during the overhaul for the first time. The detected source terms were the same for all measurement conditions, but the measurement was not quantitative analysis. It needs Spectrum Analysis Program to acquire quantitative analysis and we are developing the system. If the system is set-up in the CZT monitoring system, we will be able to know detail information of nuclides more. The result of spectra was the same regardless of measurement conditions and the intensity of the major nuclides is different obviously according to the measurement points. Even though the results only give US the information of the kinds of nuclides without any other information, the meaning is very significant to US, because the measurement is performed for the first time all over country. Especially, the result of both Red Plot and Blue Plot is very interesting in that the primary coolant is (Red plot) inside the pipe whereas it is not (Blue plot) inside the steam generator. Our study will be continued to find the reasons

  7. Nuclide Inventory Calculation Using MCNPX for Wolsung Unit 1 Reactor Decommissioning

    The CINDER90 computation process involves utilizing linear Markovian chains to determine the time dependent nuclide densities. The CINDER90 depletion algorithm is implemented the MCNPX code package. The coupled depletion process involves a Monte-Carlo steady-state reaction rate calculation linked to a deterministic depletion calculation. The process is shown in Fig.1. MCNPX runs a steady state calculation to determine the system eigenvalue collision densities, recoverable energies from fission and neutrons per fission events. In order to generate number densities for the next time step, the CINDER90 code takes the MCNPX generated values and performs a depletion calculation. MCNPX then takes the new number densities and caries out a new steady-stated calculation. The process repeats itself until the final time step. This paper describe the preliminary source term and nuclide inventory calculation of Candu single fuel channel using MCNPX, as a part of the activities to support the equilibrium core model development and decommissioning evaluation process of a Candu reactor. The aim of this study was to apply the MCNPX code for source term and nuclide inventory calculation of Candu single fuel channel. Nuclide inventories as a function of burnup will be used to model an equilibrium core for Candu reactor. The core lifetime neutron fluence obtained from the model is used to estimate radioactivity at the stage of decommisioning. In general, as expected, the actinides and fission products build up increase with increasing burnup. Despite the fact that the MCNPX code is still in development we can conclude that the code is capable of obtaining relevant results in burnup and source term calculation. It is recommended that in the future work, the calculation has to be verified on the basis of experimental data or comparison with other codes

  8. Progress of nuclide tracing technique in the study of soil erosion in recent decade

    In the last decade nuclide tracing technique has been widely employed in the investigation of soil erosion, which makes the studies of soil erosion into a new and rapid development period. This paper tried to review the recent progress of using 137Cs, 210Pbex, 7Be, composite tracers and REE-INAA in soil erosion rate, sedimentation rate, sediment source and soil erosion processes study, and also the existing research results. The trends for future development and questions are also discussed. (authors)

  9. Tandem accelerators

    After the installation of Ti-acceleration tubes and substantial modifications and additions to the EN tandem accelerator the performance of the machine has stabilized. The voltage behaviour of the tubes obviously improves as conditioning times necessary to run up to 6 MV decrease. A gridded lens has been added at the entrance of the first acceleration tube, and a second foil stripper is now installed in the short dead section between the high-energy tubes. The MP tandem also has been running stably during most of the year. However, beam instabilities originating from the last tube section and wear problems at the low-energy set of pelletron-chains caused some loss of beam time. During the fall, one set of pelletron charging chains has to be replaced after 49,000 hours of operation. In the course of the year, the MP and the EN tandem accelerators finished their 100,000th and 150,000th hours of operations, respectively. Preparations for the installation of the 3 MV negative heavy ion injector for the MP are progressing steadily. External beam transport, terminal ion optics, and data acquisition and control systems are to a major extent completed; the integration of the terminal power supplies has started. After the final assembly of the accelerator column structure, first voltage runs can be performed. (orig.)

  10. 2014 Joint International Accelerator School: Beam Loss and Accelerator Protection

    JAS - Joint US-CERN-Japan-Russia Accelerator School

    2016-01-01

    Many particle accelerators operate with very high beam power and very high energy stored in particle beams as well as in magnet systems. In the future, the beam power in high intensity accelerators will further increase. The protection of the accelerator equipment from the consequences of uncontrolled release of the energy is essential. This was the motivation for organizing a first school on beam losses and accelerator protection (in general referred to as machine protection). During the school the methods and technologies to identify, mitigate, monitor and manage the technical risks associated with the operation of accelerators with high-power beams or subsystems with large stored energy were presented. At the completion of the school the participants should have been able to understand the physical phenomena that can damage machine subsystems or interrupt operations and to analyze an accelerator facility to produce a register of technical risks and the corresponding risk mitigation and management strategie...

  11. Fukushima-derived fission nuclides monitored around Taiwan: Free tropospheric versus boundary layer transport

    Huh, Chih-An; Hsu, Shih-Chieh; Lin, Chuan-Yao

    2012-02-01

    The 2011 Fukushima nuclear accident in Japan was the worst nuclear disaster following the 1986 Chernobyl accident. Fission products (nuclides) released from the Fukushima plant site since March 12, 2011 had been detected around the northern hemisphere in about two weeks and also in the southern hemisphere about one month later. We report here detailed time series of radioiodine and radiocesium isotopes monitored in a regional network around Taiwan, including one high-mountain and three ground-level sites. Our results show several pulses of emission from a sequence of accidents in the Fukushima facility, with the more volatile 131I released preferentially over 134Cs and 137Cs at the beginning. In the middle of the time series, there was a pronounced peak of radiocesium observed in northern Taiwan, with activity concentrations of 134Cs and 137Cs far exceeding that of 131I during that episode. From the first arrival time of these fission nuclides and their spatial and temporal variations at our sampling sites and elsewhere, we suggest that Fukushima-derived radioactive nuclides were transported to Taiwan and its vicinity via two pathways at different altitudes. One was transported in the free troposphere by the prevailing westerly winds around the globe; the other was transported in the planetary boundary layer by the northeast monsoon wind directly toward Taiwan.

  12. Continuous time markov process model for nuclide decay chain transport in the fractured rock medium

    A stochastic approach using continuous time Markov process is presented to model the one dimensional nuclide transport in fractured rock media as a further extension for previous works. Nuclide transport of decay chain of arbitrary length in the single planar fractured rock media in the vicinity of the radioactive waste repository is modeled using a continuous time Markov process. While most of analytical solutions for nuclide transport of decay chain deal with the limited length of decay chain, do not consider the case of having rock matrix diffusion, and have very complicated solution form, the present model offers rather a simplified solution in the form of expectance and its variance resulted from a stochastic modeling. As another deterministic way, even numerical models of decay chain transport, in most cases, show very complicated procedure to get the solution and large discrepancy for the exact solution as opposed to the stochastic model developed in this study. To demonstrate the use of the present model and to verify the model by comparing with the deterministic model, a specific illustration was made for the transport of a chain of three member in single fractured rock midium with constant groundwater flow rate in the fracture, which ignores the rock matrix diffusion and shows good capability to model the fractured media around the repository. (Author)

  13. Development of a method to determine the nuclide inventory in bituminized waste packages

    Until the 1980s, bitumen was used as a conditioning agent for weak to medium radioactive liquid waste. Its use can be ascribed mainly to the properties that indicated that the matrix was optimal. However, fires broke out repeatedly during the conditioning process, so that the method is meanwhile no longer permitted in Germany. There are an estimated 100 waste packages held by the public authorities in Germany that require a supplementary declaration. In contrast to the common matrices, such as for example resins or sludges, there is still no standardized technology for taking samples and subsequently determining the radio-nuclide for bitumen. Aspects, such as the thermoplastic behaviour, make determining the nuclide inventory more difficult in bituminized waste packages. The development of a standardized technology to take samples with a subsequent determination of the radio-nuclide analysis is the objective of a project funded by the BMBF. Known, new methods, specially developed for the project, are examined on inactive bitumen samples and then transferred to active samples. At first non-destructive methods are used. The resulting information forms an important basis to work out and apply destructive strategy for sampling and analysis. Since the project is on-going, this report can only address the development of the sampling process. By developing a sampling system, it will be possible to take samples from an arbitrary selected location of the package across the entire matrix level and thus gain representative analysis material. The process is currently being optimized. (orig.)

  14. LAKE-0: a model for the simulation of nuclides transfer in lake scenarios

    This report presents documentation and a user's manual for the program LAKE-0, a mathematical model of nuclides transfer in lake scenarios. Mathematical equations and physical principles used to develop the code are presented in section 2. The program use is presented in section 3 including input data sets and output data. Section 4 presents two example problems, and some results. The complete program listing including comments is presented in Appendix A. Nuclides are assumed to center the lake via atmospheric deposition and carried by the water runoff and the dragged sediments from the adjacent catchment. The dynamics of the nuclides inside the lake is based in the model proposed by Codell (11) as modified in (5). The removal of concentration from the lake water is due to out flow from the lake and to the transfer of activity to the button sediments. The model has been applied to the Esthwaite Water (54 degree celsius 2 l'N, 03 degree celsius 00'W at 65 m. asi.) in the frame of the VAMP Aquatic Working Group (8) and to Devoke Water (5 21.5'N, 03H8'W at 230 m. asi.). (Author). 13 refs

  15. Neutron cross sections of 28 fission product nuclides adopted in JENDL-1

    This is the final report concerning the evaluated neutron cross sections of 28 fission product nuclides adopted in the first version of Japanese Evaluated Nuclear Data Library (JENDL-1). These 28 nuclides were selected as being most important for fast reactor calculations, and are 90Sr, 93Zr, 95Mo, 97Mo, 99Tc, 101Ru, 102Ru, 103Rh, 104Ru, 105Pd, 106Ru, 107Pd, 109Ag, 129I, 131Xe, 133Cs, 135Cs, 137Cs, 143Nd, 144Ce, 144Nd, 145Nd, 147Pm, 147Sm, 149Sm, 151Sm, 153Eu and 155Eu. The status of the experimental data was reviewed over the whole energy range. The present evaluation was performed on the basis of the measured data with the aid of theoretical calculations. The optical and statical models were used for evaluation of the smooth cross sections. An improved method was developed in treating the multilevel Breit-Wigner formula for the resonance region. Various physical parameters and the level schemes, adopted in the present work are discussed by comparing with those used in the other evaluations such as ENDF/B-IV, CEA, CNEN-2 and RCN-2. Furthermore, the evaluation method and results are described in detail for each nuclide. The evaluated total, capture and inelastic scattering cross sections are compared with the other evaluated data and some recent measured data. Some problems of the present work are pointed out and ways of their improvement are suggested. (author)

  16. AMS Measurements of Supernova-Produced Radionuclides in Deep-Sea Sediment Cores

    Full text: Accelerator Mass Spectrometry (AMS) provides the highest sensitivity for measurements of long-lived radionuclides with half-lifes in the order of million years. We apply this method to search for live supernova (SN)-produced radionuclides on Earth. An indication to recent SN activity in our solar neighborhood is the existence of a thin, hot cavity in the local interstellar medium, embedding our solar system. This so called super bubble, the Local Bubble, was produced by multiple SN explosions, starting ∼14 Myr ago. Nuclides, which are synthesized in massive stars and during their explosions, are then entrained in the SN shell and may be transported to the solar system and thus into Earth archives, if such an event happens within a short distance. Two deep-sea sediment cores originating from the Indian Ocean have been selected to search for the SN-produced radionuclides 26Al, 53Mn, 60Fe and 244Pu in the time range of 2-3 Myr. We aim to measure these isotopes at different laboratories with high time resolution with the goal to confirm a previously found SN signal in a ferromanganese crust from the Pacific Ocean. (author)

  17. Accelerators for therapy

    In the past decades circular and linear electron accelerators have been developed for clinical use in radiation therapy of tumors with the aim of achieving a high radiation dose in the tumor and as low as possible dose in the adjacent normal tissues. Today about one thousand accelerators are in medical use throughout the world and many hundred thousand patients are treated every day with accelerator-produced radiation. There exists, however, a large number of patients who cannot be treated satisfactorily in this way. New types of radiations such as neutrons, negative pions, protons and heavy ions were therefore tested recently. The clinical experience with these radiations and with new types of treatment procedures indicate that in future the use of a scanning beam of high energy protons might be optimal for the treatment of tumors. (orig.)

  18. Selection of nuclide decay chains for use in the assessment of the radiological impact of geological repositories for radioactive waste

    The criteria for selecting nuclide decay chains for use in the assessment of the radiological impact of geological repositories for radioactive waste are given. The reduced chains recommended for use with SYVAC are described. (author)

  19. Nuclide transport of decay chain in the fractured rock medium: a model using continuous time Markov process

    A model using continuous time Markov process for nuclide transport of decay chain of arbitrary length in the fractured rock medium has been developed. Considering the fracture in the rock matrix as a finite number of compartments, the transition probability for nuclide from the transition intensity between and out of the compartments is represented utilizing Chapman-Kolmogorov equation, with which the expectation and the variance of nuclide distribution for the fractured rock medium could be obtained. A comparison between continuous time Markov process model and available analytical solutions for the nuclide transport of three decay chains without rock matrix diffusion has been made showing comparatively good agreement. Fittings with experimental breakthrough curves obtained with nonsorbing materials such as NaLS and uranine in the artificial fractured rock are also made. (author)

  20. A region of oblate nuclides centred at Z = 114 and of spherical nuclides centred at the magic nucleus - A possible scenario to understand the production of superheavy elements beyond copernicium

    The recent experiments at FLNR (Dubna) demonstrated that cross sections to produce super-heavy elements (SHEs) by 48Ca induced reactions on actinide targets increase beyond Z=111, reach a maximum of 5 pb at Z=114/115, and fall below the 1 pb-level at Z=118. A scenario is proposed to understand the findings within the frame of former experimental results of heavy element production and theoretical predictions on the stability of the nuclides concerned. New ingredients introduced are: -1) to shift the next proton shell beyond Pb from Z=114 to Z=122, -2) the isotopes of elements Z=112 to Z=118 are deformed and their nuclei have oblate shapes, and -3) the fission barriers around the next magic nucleus 306122184 are larger than the neutron separation energies and reach values in the range of 10 MeV. The ascent of the flat top at 306122184 is described by the proposed scenario, which likewise excludes to reach the doubly closed shell region at the top by today's experimental methods in complete fusion reactions. (authors)

  1. A region of oblate nuclides centred at Z = 114 and of spherical nuclides centred at the magic nucleus - A possible scenario to understand the production of superheavy elements beyond copernicium

    Armbruster P.

    2011-10-01

    Full Text Available The recent experiments at FLNR, Dubna, demonstrated that cross sections to produce SHEs by 48Ca induced reactions on actinide targets increase beyond Z = 111, reach a maximum of 5 pb at Z = 114/115, and fall below the 1 pb-level at Z = 118. A scenario is proposed to understand the findings within the frame of former experimental results of heavy element production and theoretical predictions on the stability of the nuclides concerned. New ingredients introduced are 1 to shift the next proton shell beyond Pb from Z = 114 to Z = 122, 2 the isotopes of elements Z = 112 to Z = 118 are deformed and their nuclei have oblate shapes, and 3 the fission barriers around the next magic nucleus 306122184 are larger than the neutron separation energies and reach values in the range of 10 MeV. The ascent of the flat top at 306122184 is described by the proposed scenario, which likewise excludes to reach the doubly closed shell region at the top by today s experimental methods in complete fusion reactions.

  2. Fixed-Target Electron Accelerators

    A tremendous amount of scientific insight has been garnered over the past half-century by using particle accelerators to study physical systems of sub-atomic dimensions. These giant instruments begin with particles at rest, then greatly increase their energy of motion, forming a narrow trajectory or beam of particles. In fixed-target accelerators, the particle beam impacts upon a stationary sample or target which contains or produces the sub-atomic system being studied. This is in distinction to colliders, where two beams are produced and are steered into each other so that their constituent particles can collide. The acceleration process always relies on the particle being accelerated having an electric charge; however, both the details of producing the beam and the classes of scientific investigations possible vary widely with the specific type of particle being accelerated. This article discusses fixed-target accelerators which produce beams of electrons, the lightest charged particle. As detailed in the report, the beam energy has a close connection with the size of the physical system studied. Here a useful unit of energy is a GeV, i.e., a giga electron-volt. (ne GeV, the energy an electron would have if accelerated through a billion volts, is equal to 1.6 x 10-10 joules.) To study systems on a distance scale much smaller than an atomic nucleus requires beam energies ranging from a few GeV up to hundreds of GeV and more

  3. Formulation of Relationships between the Radiation Exposure of Tissues and the Excretion Rate of Nuclides

    The organization of protection against undue occupational exposure to internal radiation involves several processes: 1 1. Decisions as to the highest dose-rates, for the body or for particular organs-, that can be regarded as permissible; 2. Estimation, for all relevant nuclides, of the intakes, and of the body burdens, which would cause any such dose-rates to be reached or sustained; 3. Monitoring of exposed individuals to determine what fraction of a permissible body burden of any nuclide is retained in the body. Techniques of monitoring by whole-body counting, or by data on excretion or exhalation rates, are relevant to the Symposium. Several major problems are involved: (a) For most radionuclides, insufficient metabolic data are available to link tissue dose-rates either with body burdens or with excretion rates, at least as based on adequately large numbers of normal human subjects; (b) The large variability between different subjects in physiological functions, such as excretion or clearance rates, limits severely the inferences that can be made from isolated human observations, and restricts also the deductions as to body burden that can be drawn from the excretion rates observed in any individual; (c) The complex variation of excretion rate with time after a single intake cf many, nuclides prevents any direct deduction of body burden from excretion rate when the time course of intake is unknown, except in the special case of a nuclide which is excreted at a rate which decreases (mono-) exponentially with time since intake; (d) In particular, many radionuclides which are of particular importance because they are highly concentrated and long retained in certain organs, may show initial rapid excretion of the fraction of intake which is not so concentrated, and much slower and more prolonged excretion of the retained part. A small recent intake will thus contribute preponderating to the excretion as compared with that from a much larger and more important

  4. Considerations on the activity concentration determination method for low-level waste packages and nuclide data comparison between different countries

    In low-level waste disposal, acceptable activity concentration limits are regulated for individual nuclides and groups of nuclides according to the conditions of each disposal site. Such regulated limits principally concern total alpha and beta /gamma activity as well as nuclides such as C-14, Ni-63, and Pu-238 which are long-lived and difficult to measure (hereinafter referred to as difficult-to-measure nuclides). Before waste packages are transported to the disposal site, the activities or activity concentrations of the regulated nuclides and groups of nuclides in the waste packages must be assessed and declared. A generally applicable theoretical method to determine these activities is lacking at present. Therefore, to meet this requirement, for NPP waste each country independently samples actual waste and carries out radiochemical analyses on these samples. The activity concentrations of difficult-to-measure nuclides are then determined by statistical correlation of the measured data between difficult-to-measure nuclides and Co-60 and Cs-137 which are measurable from outside the waste packages (hereinafter referred to as key nuclides). This method is called 'Scaling Factor Method'. It is widely adopted as a method for determining the activity concentrations of the limited nuclides in low-level waste packages from NPP, and it is also approved by responsible authorities in the respective country. In the past, each country independently determined scaling factors based on measurements on samples from the local NPPs. In the first part of this study, the possibility of an international scaling factor assessment using a database integrating data from different countries was studied by comparing radiochemical analysis data between Germany, Japan, and the United States. These countries have accumulated a large number of those nuclide data required to determine scaling factors. Statistical values such as correlation coefficients change with an accumulation of data. In

  5. Elusive or illusive? Finding live supernova-born radionuclides and superheavy elements on earth by accelerator mass spectrometry

    Full text: It is of great interest to detect and trace freshly produced elements as a direct proof of our understanding of nucleosynthesis. The production of lighter elements can be studied in the laboratory, and in-space γ-rays from the decay of e.g. 26Al and 44Ti can nowadays be observed via space-born instruments. Many nuclear reactions near the valley of stability have been studied in the laboratory, and radioactive beam facilities now open a wide area for studying reactions off stability. However, one important issue is the experimental proof of r-process scenarios via the direct observation of nuclides generated in the r-process. Some ten years ago it was pointed out that there might be a chance for finding long-lived radionuclides in terrestrial archives, which were originally produced in a supernova (SN). Several candidates had been identified, among them 26Al, 53Mn, 60Fe, 146Sm, 182Hf, 244Pu which are produced in sufficient amounts to be in principle detectable on Earth. We explore the detection of very feeble natural traces of the long-lived radionuclides 244Pu (t1/2 = 81 Ma) and 247Cm (15.6 Ma). Such a finding would be of great interest in nuclear astrophysics complementing the recent detection of possibly supernova-produced 60Fe. The expected extremely small concentrations of 244Pu and 247Cm, makes accelerator mass spectrometry (AMS) as the favorite method. First measurements of 244Pu looking for a supernova-produced evidence have been performed recently in deep-sea manganese nodules and deep-sea sediments. These measurements are at the edge of detection limit. At the VERA laboratory we have continued to search for 244Pu and have extended our search to the radionuclide 247Cm. Compared to previous 244Pu measurements, ten times higher sample mass is now available. Due to the long half-lives of 244Pu and 247Cm, one can reach back in time much further than with 60Fe. In addition to single events, one may be sensitive to the steady-state abundance of these

  6. Particle acceleration

    Vlahos, L.; Machado, M. E.; Ramaty, R.; Murphy, R. J.; Alissandrakis, C.; Bai, T.; Batchelor, D.; Benz, A. O.; Chupp, E.; Ellison, D.

    1986-01-01

    Data is compiled from Solar Maximum Mission and Hinothori satellites, particle detectors in several satellites, ground based instruments, and balloon flights in order to answer fundamental questions relating to: (1) the requirements for the coronal magnetic field structure in the vicinity of the energization source; (2) the height (above the photosphere) of the energization source; (3) the time of energization; (4) transistion between coronal heating and flares; (5) evidence for purely thermal, purely nonthermal and hybrid type flares; (6) the time characteristics of the energization source; (7) whether every flare accelerates protons; (8) the location of the interaction site of the ions and relativistic electrons; (9) the energy spectra for ions and relativistic electrons; (10) the relationship between particles at the Sun and interplanetary space; (11) evidence for more than one acceleration mechanism; (12) whether there is single mechanism that will accelerate particles to all energies and also heat the plasma; and (13) how fast the existing mechanisms accelerate electrons up to several MeV and ions to 1 GeV.

  7. Accelerator design

    The feasibility of constructing a TeV region electron-positron linear collider in Japan is discussed. The design target of the collider is given as follows: Energy, 1 TeV + 1 TeV; luminosity, 1032-1033/cm2/s; total length, 25km; electric power, 250MW; energy dispersion, 1%-10%; the start of the first experiment, early 1990s. For realizing the above target, the following research and developmental works are necessary. (a) Development of an acceleration tube with short filling time and high shunt resistance. (b) Short pulse microwave source with high peak power. (c) High current, single bunch linac. (d) Beam dynamics. As for the acceleration tube, some possibility is considered: For example, the use of DAW (Disk and Washer) which is being developed for TRISTAN as a traveling-wave tube; and the Jungle Gym-type acceleration tube. As a promising candidate for the microwave source, the Lasertron has been studied. The total cost of the collider construction is estimated to be about 310 billion yen, of which 120 billion yen is for the tunnel and buildings, and 190 billion yen for the accelerator facilities. The operation cost is estimated to be about 3 billion yen per month. (Aoki, K.)

  8. Accelerator operations

    This section is concerned with the operation of both the tandem-linac system and the Dynamitron, two accelerators that are used for entirely different research. Developmental activities associated with the tandem and the Dynamitron are also treated here, but developmental activities associated with the superconducting linac are covered separately because this work is a program of technology development in its own right

  9. Advanced accelerators

    This report discusses the suitability of four novel particle acceleration technologies for multi-TeV particle physics machines: laser driven linear accelerators (linac), plasma beat-wave devices, plasma wakefield devices, and switched power and cavity wakefield linacs. The report begins with the derivation of beam parameters practical for multi-TeV devices. Electromagnetic field breakdown of materials is reviewed. The two-beam accelerator scheme for using a free electron laser as the driver is discussed. The options recommended and the conclusions reached reflect the importance of cost. We recommend that more effort be invested in achieving a self-consistent range of TeV accelerator design parameters. Beat-wave devices have promise for 1-100 GeV applications and, while not directly scalable to TeV designs, the current generation of ideas are encouraging for the TeV regime. In particular, surfatrons, finite-angle optical mixing devices, plasma grating accelerator, and the Raman forward cascade schemes all deserve more complete analysis. The exploitation of standard linac geometry operated in an unconventional mode is in a phase of rapid evolution. While conceptual projects abound, there are no complete designs. We recommend that a fraction of sponsored research be devoted to this approach. Wakefield devices offer a great deal of potential; trades among their benefits and constraints are derived and discussed herein. The study of field limitation processes has received inadequate attention; this limits experiment designers. The costs of future experiments are such that investment in understanding these processes is prudent. 34 refs., 12 figs., 3 tabs

  10. IRACM : A code system to calculate induced radioactivity produced by ions and neutrons

    It is essential to estimate of radioactivity induced in accelerator components and samples bombarded by energetic ion beams and the secondary neutrons of high-energy accelerator facilities in order to reduce the amount of radioactive wastes and to minimize radiation exposure to personnel. A computer code system IRACM has been developed to estimate product nuclides and induced radioactivity in various radiation environments of accelerator facilities. Nuclide transmutation with incident particles of neutron, proton, deuteron, alpha, 12C, 14N, 16O, 20Ne and 40Ar can be computed for arbitrary multi-layer target system in a one-dimensional geometry. The code system consists of calculation modules and libraries including activation cross sections, decay data and photon emission data. The system can be executed in both FACOM-M780 mainframe and DEC workstations. (author)

  11. Measuring excitation functions needed to interpret cosmogenic nuclide production in lunar rocks

    Radionuclides produced in lunar rocks by cosmic ray interactions are measured using Accelerator Mass Spectrometry or gamma-ray spectroscopy. From these measurements, estimates of the solar proton flux over time periods characterized by the half-life of the isotope under study can be made, if all the cross sections for all the reactions of all cosmic ray particles with all elements found in lunar rocks are known. Proton production cross sections are very important because ∼98% of solar cosmic rays and ∼87% of galactic cosmic rays are protons in the lunar environment. Many of the needed cross sections have never been measured. Targets of C, Al, Si, SiO2, Mg, K, Ca, Fe and Ni have been irradiated using three accelerators to cover a proton energy range of 25 endash 500 MeV. Excitation functions for 7Be, 10Be, 22Na, and 26Al production from Mg and Al will be reported, and the consequences of using these new cross section values to estimate solar proton fluxes discussed. copyright 1997 American Institute of Physics

  12. Compact pulsed accelerator

    The formation of fast pulses from a current charged transmission line and opening switch is described. By employing a plasma focus as an opening switch and diode in the prototype device, a proton beam of peak energy 250 keV is produced. The time integrated energy spectrum of the beam is constructed from a Thomson spectrograph. Applications of this device as an inexpensive and portable charged particle accelerator are discussed. 7 refs., 5 figs., 1 tab

  13. Particle acceleration in space and laboratory plasmas

    The general principle of charged particle acceleration in space and laboratory plasmas is illustrated by a discussion of particular types of acceleration mechanisms which can be classified as either deterministic processes or stochastic processes. Acceleration by parallel electric fields, produced in double layers is an example of a deterministic process. Fermi acceleration and acceleration by turbulent wave fields are examples of stochastic processes. The physical acceleration mechanism involved in each type of process is discussed and examples given for space and laboratory plasmas. (author)

  14. MUON ACCELERATION

    BERG,S.J.

    2003-11-18

    One of the major motivations driving recent interest in FFAGs is their use for the cost-effective acceleration of muons. This paper summarizes the progress in this area that was achieved leading up to and at the FFAG workshop at KEK from July 7-12, 2003. Much of the relevant background and references are also given here, to give a context to the progress we have made.

  15. KEKB accelerator

    KEKB, the B-Factory at High Energy Accelerator Research Organization (KEK) recently achieved the luminosity of 1 x 1034 cm-2s-1. This luminosity is two orders higher than the world's level at 1990 when the design of KEKB started. This unprecedented result was made possible by KEKB's innovative design and technology in three aspects - beam focusing optics, high current storage, and beam - beam interaction. Now KEKB is leading the luminosity frontier of the colliders in the world. (author)

  16. Accelerating networks

    Evolving out-of-equilibrium networks have been under intense scrutiny recently. In many real-world settings the number of links added per new node is not constant but depends on the time at which the node is introduced in the system. This simple idea gives rise to the concept of accelerating networks, for which we review an existing definition and-after finding it somewhat constrictive-offer a new definition. The new definition provided here views network acceleration as a time dependent property of a given system as opposed to being a property of the specific algorithm applied to grow the network. The definition also covers both unweighted and weighted networks. As time-stamped network data becomes increasingly available, the proposed measures may be easily applied to such empirical datasets. As a simple case study we apply the concepts to study the evolution of three different instances of Wikipedia, namely, those in English, German, and Japanese, and find that the networks undergo different acceleration regimes in their evolution

  17. Linear accelerator for burner-reactor

    Future development of nuclear power engineering depends on the successful solution of two key problems of safety and utilization of high level radioactive wastes (HLRW) of atomic power plants (APP). Modern methods of HLRW treatment involve solidification, preliminary storing for a period of 30-50 years necessary for the decay of long-living nuclides and final burial in geological formations several hundred meters below the ground surface. The depth burial of the radioactive wastes requires complicated under ground constructions. It's very expensive and doesn't meet modern ecological requirements. Alternative modern and more reasonable methods of APP HLRW treatment are under consideration now. One of the methods involves separation of APP waste radionuclides for use in economy with subsequent transmutation of the long-living isotopes into the short-living ones by high-intensity neutron fluxes generated by proton accelerators. The installation intended for the long-living radionuclides transmutation into the short-living ones is called burner-reactor. It can be based on the continuous regime proton accelerator with 1.5 GeV energy, 0.3 A current and beam mean power of 450 MW. The preferable type of the proton accelerator with the aforementioned parameters is the linear accelerator

  18. Decontamination Experiments on Intact Pig Skin Contaminated with Beta-Gamma- Emitting Nuclides

    Edvardsson, K.A.; Hagsgaard, S. [AB Atomenergi, Nykoeping (Sweden); Swensson, A. [Dept. of Occupational Medicine, Karolinska Sjukhuset, Stockholm (Sweden)

    1966-11-15

    A number of decontamination experiments have been performed on intact pig skin. In most of the experiments NaI-131 in water solution has been utilized because this nuclide is widely used within the Studsvik research establishment, is easy to detect and relatively harmless, and is practical to use in these experiments. Among the {beta} {gamma}-nuclides studied 1-131 has furthermore proved to be the one most difficult to remove from the skin. The following conclusions and recommendations regarding the decontamination of skin are therefore valid primarily for iodine in the form of Nal, but are probably also applicable to many other {beta} {gamma}-nuclides. a) A prolonged interval between contamination and decontamination has a negative effect on the result of the decontamination. Therefore start decontamination as soon as possible after the contamination. b) Soap and water has proved to be the most suitable decontamination agent. A number of other agents have appeared to be harmful to the skin. Therefore, first of all use only soap and water in connection with gentle rubbing. c) No clear connection between the temperature of the water for washing and the result of the decontamination has been demonstrated. d) Skin not degreased before the contamination seems to be somewhat easier to decontaminate than degreased skin, particularly if the activity has been on the skin for a long time. Therefore do not remove the sebum of the skin when engaged on radioactive work involving contamination risks. e) Irrigation of the contaminated surface with a solution containing the corresponding inactive ions or ordinary water in large quantities may considerably decrease the skin contamination. f) In radioactive work of long duration involving high risks of contamination prophylactic measures in the form of a protective substance ('invisible glove'), type Kerodex, may make decontamination easier.

  19. Transfer of nuclides from the water phase to the sediments during normal and extraordinary hydrological cycles

    Atucha I and Atucha II nuclear power plants are located on the right margin of the Parana de las Palmas river. This river belongs to the Cuenca del Plata, whose 1982-1983 hydrologic cycle registered the greatest freshets of the century. Works and studies previously fixed had to be altered and investigations were adapted to the possibilities and the particular hydric conditions verified. Considerations on the transfer of nuclides between water and sediments are presented. The floods reduce the water-sediments contact time on the bed of the river. In outer areas, the waters labelled by the nuclear power plant effluent discharge favor the infiltration in alluvial soils, as well as the exchange with the sediments. The investigations carried out for the phase near to the discharge of liquid effluents (related to the critical group) made possible to prove the characteristics of the path of the liquid wastes released, the distribution coefficient and the fixation or penetrability of some nuclides in soils of the floody valley. In this manner, a balance of radioactive nuclides incorporated to soils and sediments from the neighbourhood of Atucha and the water-course of Parana de las Palmas river is obtained. The presence of 60Co and 137Cs in the floody soils on the right margin of this river was detected and measured during the greatest flood of the century. On the other hand, 144Ce, 51Cr, 106Ru and 90Sr have not been detected. The detection of artificial radioisotopes turns out to be impossible in normal hydrological years, even in the sorroundings of the nuclear power plant or the critical group (from the point of view of the surface waters, The Fishing Club, 3 km down stream). (M.E.L.)

  20. Decontamination Experiments on Intact Pig Skin Contaminated with Beta-Gamma- Emitting Nuclides

    A number of decontamination experiments have been performed on intact pig skin. In most of the experiments NaI-131 in water solution has been utilized because this nuclide is widely used within the Studsvik research establishment, is easy to detect and relatively harmless, and is practical to use in these experiments. Among the β γ-nuclides studied 1-131 has furthermore proved to be the one most difficult to remove from the skin. The following conclusions and recommendations regarding the decontamination of skin are therefore valid primarily for iodine in the form of Nal, but are probably also applicable to many other β γ-nuclides. a) A prolonged interval between contamination and decontamination has a negative effect on the result of the decontamination. Therefore start decontamination as soon as possible after the contamination. b) Soap and water has proved to be the most suitable decontamination agent. A number of other agents have appeared to be harmful to the skin. Therefore, first of all use only soap and water in connection with gentle rubbing. c) No clear connection between the temperature of the water for washing and the result of the decontamination has been demonstrated. d) Skin not degreased before the contamination seems to be somewhat easier to decontaminate than degreased skin, particularly if the activity has been on the skin for a long time. Therefore do not remove the sebum of the skin when engaged on radioactive work involving contamination risks. e) Irrigation of the contaminated surface with a solution containing the corresponding inactive ions or ordinary water in large quantities may considerably decrease the skin contamination. f) In radioactive work of long duration involving high risks of contamination prophylactic measures in the form of a protective substance ('invisible glove'), type Kerodex, may make decontamination easier

  1. Statistical effects in beta-delayed neutron emission from fission product nuclides

    The delayed neutron spectra for the precursors Rb-93, 94, 95, 96, 97 and Cs-145 were measured by use of the on-line isotope separator facility TRISTAN and a time-of-flight (TOF) spectrometer. Flight paths were used that provided, for energies below 70 keV, a FWHM energy resolution between 2 and 4 percent. Each spectrum showed discrete neutron peaks below 156 keV, with as many as 26 in the Rb-95 spectra. Level densities near the neutron binding energy in the neutron-emitting nuclide were deduced using a missing-level indicator based on a Porter-Thomas distribution of neutron peak intensities. The resulting level density data were compared to the predictions of the Gilbert and Cameron formulism and to those of Dilg, Schantl, Vonach and Uhl. Comparisons were made between the empirically-based level parameter a and the values predicted by each model for Sr-93, 94, 95, 97 and Ba-145. The two models appear, within the uncertainties, to be equally capable of describing these neutron-rich nuclides and equally as capable for them as they are for nuclides in the valley of beta stability. Measurements of the neutron strength function are sometimes possible with the present TOF system for neutron decays with competing neutron branches to levels in the grandchild nucleus. A value for the d-wave strength function of Sr-96 is found to be (4.2 +- 1.1)/104. Improvements in the TOF system, allowing the measurement of the neutron strength function for the more general case, are discussed. 72 refs., 56 figs., 16 tabs

  2. Impact of vegetation change on the mobility of uranium- and thorium-series nuclides in soils

    Gontier, A.; Rihs, S.; Turpault, M.-P.; Chabaux, F.

    2012-04-01

    The effect of land cover change on chemical mobility and soil response was investigated using short- and long-lived nuclides from the U- and Th series. Indeed, the matching of these nuclides half-live to the pedogenic processes rates make these nuclides especially suitable to investigate either time or mechanism of transfers within a soil-water-plant system. This study was carried out from the experimental Breuil-Chenue site (Morvan mountains, France). The native forest (150 year-old) was partially clear-felled and replaced in 1976 by mono-specific plantations distributed in different stands. Following this cover-change, some mineralogical changes in the acid brown soil were recognized (Mareschal, 2008). Three soil sections were sampled under the native forest and the replanted oak and Douglas spruce stands respectively. The (238U), (234U), (230Th), (226Ra), (232Th) and (228Ra) activities were analysed by thermal ionization mass spectrometry (TIMS), inductively coupled plasma mass spectrometry (MC-ICPMS) and gamma spectrometry. Significant differences in U, Th, and Ra activities were observed between the soils located under the native forest or the replanted-trees stands, mostly dominated by a large uranium mobilization from the replanted soils. Moreover, all the investigated U and Th-series activity ratios show a contrasted trend between the shallowest horizons (0-50cm) and the deepest one (below 50cm), demonstrating the chemical effect of the vegetation change on the shallow soil layers. Using a continuous open-system leaching model, the coupled radioactive disequilibria measured in the different soil layers permit to quantify the rate of the radionuclides mobilities. Reference: Mareschal, L., 2008. Effet des substitutions d'essences forestières sur l'évolution des sols et de leur minéralogie : bilan après 28 ans dans le site expérimental de Breuil (Morvan) Université Henri Poincaré, Nancy-I.

  3. Attempt of concentrating a new natural spontaneously fissile nuclide from geothermal brine of the Cheleken peninsula

    The study is aimed at concentration of yet nonidentified spontaneous fission nuclide (NSFN), discovered in geothermal brines of the Cheleken peninsula, when coprecipitation with inorganic collectors (metal hydroxides, ZnS, FeS, BaSO4; ionic exchange on organic and inorganic sorbents, as well as reduction by metals (Fe, Al) are used. The NSFN enrichment level turns out to be insufficient to identify its atomic number by physical methods. However, using the obtained data and measurement results of NSFN spontaneous fission activity in different concentrates, some of its chemical properties are studied. A certain analogy in chemical behaviour of NSFN and noble metals like Au and Hg is noted

  4. Calibration techniques and error analysis for phoswich counting of actinide nuclides at Oak Ridge National Laboratory

    One of the most difficult and demanding areas of low-level counting is the detection of actinides in vivo. In the case of inhalation of these nuclides, it is common practice at many installations to determine the resulting lung burden by external counting of low-intensity L X-rays from the daughter nucleus with either a phoswich detector or a proportional counter. Calibration techniques using these detectors are examined and possible uncertainties in the determination of lung burden by using standard techniques are discussed. The use of phoswich detectors is discussed in detail

  5. Probing the nuclide 180W for neutrinoless double-electron capture exploration

    The mass difference of the nuclides 180W and 180Hf has been measured with the Penning-trap mass spectrometer SHIPTRAP to investigate 180W as a possible candidate for the search for neutrinoless double-electron capture. The Qεε-value was measured to 143.20(27) keV. This value in combination with the calculations of the atomic electron wave functions and other parameters results in a half-life of the 0+→0+ ground-state to ground-state double-electron capture transition of approximately 5×1027 years/〈mεε[eV]〉2.

  6. A prospect of the administration against problems of environmental contamination caused by radioactive nuclides

    At first, focusing on the problem of radioactive contaminated wastes caused by Fukushima Daiichi Nuclear Accident, the Author described an outline of the waste management policy based on the law on special measures against the environmental contamination by radioactive nuclides. Next, the Author discussed a prospect of the environmental administration against the radioactive contamination problem. The most important mission of the environmental administration for the future must be to establish a social basis for the sustainable development, in other words the building-up of a newly social value added, through the measures against this unprecedented disaster. (author)

  7. Database on nuclide content of coal and gangue in Chinese coal mines

    The designing ides, structure, interface and basic function of a database are introduced of nuclide content of coal or gangue in Chinese coal mine. The design of the database adopts Sybase database system, and the database has the functions of making inquiries of keyword, classification and statistics, printing, data input which are achieved by using Power builder Language program. At the present, in this database, the data are collected on the radioactivity of natural radionuclide of 2043 coal, gangue and the other relative samples from various coal miners of all over the country. The database will provide the basic data for the environmental impact assessment of Chinese coal energy. (authors)

  8. Carborane Derivatives for Nuclide Therapy and Imaging : Synthesis and Radio-labelling

    Winberg, Karl Johan

    2003-01-01

    This thesis describes synthesis and radiohalogenation of closo-carborane and nido-carborate derivatives for application in nuclide therapy and imaging. The work could be divided in to four sections. In the first section, the synthesis of three boronated DNA-intercalators – 1–(N-9-acridinyl-3-aminopropyl)-para-carborane-12-carboxylic acid hydrogen chloride, 1-[1-(N-9-acridinyl-3-aminopropyl)-para-carborane 12-(3-propyloxi)]-1,3-propanediol, 1-(N-9-acridinyl-3-amino-propyl)-1-ortho-carborane-2-...

  9. Electron capture of nuclides 52,53,54,55,56Fe in magnetars

    LIU Jing-Jing

    2013-01-01

    Based on the theory of relativity in superstrong magnetic fields (SMFs),we have carried out an estimation on electron capture (EC) rates of nuclides 52,53,54,55,56Fe in the SMFs in magnetars.The rates of change of electronic fraction (RCEF) in the EC process are also discussed.The results show that the EC rates increase greatly and even exceeds by 4 orders of magnitude (e.g.54Fe,55Fe and 56Fe) in SMF.On the contrary,the RCEF decreases largely and even exceeds by 5 orders of magnitude in the SMF.

  10. Geochemical behaviour of natural uranium-series nuclides in geological formation

    Recent research and investigation show that the Tono uranium deposit and its natural uranium-series nuclides have been preserved, without any significant changes like re-migration or reconcentration, throughout geological events such as upheaval-submergence, marine transgression-regression, and faulting which can readily change geological, hydrogeological, and geochemical conditions. This situation might have come about as a result of being kept in a geometrical closure system, with reducing and milk alkalic geochemical conditions, from the hydrogeological and geochemical point of view. (author)

  11. An in-situ RBS system for measuring nuclides adsorbed at the liquid-solid interface

    Morita, K.; Yuhara, J.; Ishigami, R. [Nagoya Univ. (Japan). School of Engineering] [and others

    1997-03-01

    An in-situ RBS system has been developed in which heavier nuclides adsorbed at the inner surface of a thin lighter window specimen of liquid container in order to determine the rate constants for their sorption and release at the interface. The testing of a thin silicon window of the sample assembly, in which Xe gas of one atmosphere was enclosed, against the bombardment of the probing ion beam has been performed. A desorption behavior of a lead layer adsorbed at the SiO{sub 2} layer of silicon window surface into deionized water has been measured as a preliminary experiment. (author)

  12. Probabilities and energies to obtain the counting efficiency of electron-capture nuclides. KLMN model

    An intelligent computer program has been developed to obtain the mathematical formulae to compute the probabilities and reduced energies of the different atomic rearrangement pathways following electron-capture decay. Creation and annihilation operators for Auger and X processes have been introduced. Taking into account the symmetries associated with each process, 262 different pathways were obtained. This model allows us to obtain the influence of the M-electro capture in the counting efficiency when the atomic number of the nuclide is high. (Author)

  13. Stable nuclide tracer studies and human amino acid requirements. A summary

    The nutritional requirements for proteins have been estimated for various age groups. The current status of knowledge concerning the quantitative needs for specific indispensable amino acids was reviewed and it was concluded that, except for infants, current values for pre-school children, school age children and healthy adults are based on limited experimental data and/or on results from nitrogen balance determinations which are open to serious question regarding their nutritional significance. A review of 13C-labelled tracer studies carried out in MIT laboratories was undertaken to demonstrate the applicability of stable nuclide tracer studies for purposes of determining the amino acid requirements of humans. 5 refs

  14. Spectroscopy of the neutron-deficient nuclide sup 1 sup 7 sup 1 Pt

    Baeck, T; Lagergren, K; Wyss, R; Johnson, A; Greenlees, P T; Jones, P; Julin, R; Juutinen, S; Keenan, A; Kettunen, H; Kuusiniemi, P; Leino, M; Leppaenen, A P; Nieminen, P; Pakarinen, J; Rahkila, P; Uusitalo, J; Jenkins, D; Joss, D T; Muikku, M

    2003-01-01

    A number of previously unobserved gamma-rays emitted from the neutron-deficient nuclide sup 1 sup 7 sup 1 Pt have been identified using the recoil decay tagging technique. The level scheme has been updated using information from gamma-gamma coincidences and angular distribution measurements. To further confirm the assignments of the gamma-rays to sup 1 sup 7 sup 1 Pt, the events were correlated with the alpha-decay of the daughter nucleus sup 1 sup 6 sup 7 Os. (orig.)

  15. ENDF/B-IV fission-product files: summary of major nuclide data

    The major fission-product parameters [sigma/sub th/, RI, tau/sub 1/2/, E-bar/sub β/, E-bar/sub γ/, E-bar/sub α/, decay and (n,γ) branching, Q, and AWR] abstracted from ENDF/B-IV files for 824 nuclides are summarized. These data are most often requested by users concerned with reactor design, reactor safety, dose, and other sundry studies. The few known file errors are corrected to date. Tabular data are listed by increasing mass number

  16. Integral test on activation cross section of tag gas nuclides using fast neutron spectrum fields

    Aoyama, Takafumi; Suzuki, Soju [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center

    1997-03-01

    Activation cross sections of tag gas nuclides, which will be used for the failed fuel detection and location in FBR plants, were evaluated by the irradiation tests in the fast neutron spectrum fields in JOYO and YAYOI. The comparison of their measured radioactivities and the calculated values using the JENDL-3.2 cross section set showed that the C/E values ranged from 0.8 to 2.8 for the calibration tests in YAYOI and that the present accuracies of these cross sections were confirmed. (author)

  17. Accelerators and the Accelerator Community

    Malamud, Ernest; Sessler, Andrew

    2008-06-01

    In this paper, standing back--looking from afar--and adopting a historical perspective, the field of accelerator science is examined. How it grew, what are the forces that made it what it is, where it is now, and what it is likely to be in the future are the subjects explored. Clearly, a great deal of personal opinion is invoked in this process.

  18. Experimental studies of nuclides far from stability with the TRISTAN II fission-product separator at the Brookhaven National Laboratory (Yrast bands; delayed-neutron spectra). Final report, January 1, 1980-November 30, 1982

    The research program under this contract consisted of two projects; one was the study of yrast bands and the other the study of energy spectra of beta-delayed neutrons. Both utilized the TRISTAN mass separaotr at Brookhaven National Laboratory. The nuclides of interest for the yrast band project were ot produced at TRISTAN during the period of the contract, so effort was limited to planning and to presentation of papers. The neutron project required the design, construction, testing, and calibration of apparatus that is not commercially available. Neutron detectors were later made available onloan. The time-of-flight method was used, beta and neutron signals from scintillators detectors providing start and stop signals. He-3 gas and Li-6 glass scintillators were used for neutrons, plastic for betas. The best timing resolution was 2.7 nsec FWHM; including geometrical contributions,neutron FWHM energy resolution as good as 2.7% at 14 keV was obtained at 50 cm flight path. This is sufficient to deduce the natural line width of the 14 keV resonance in Sr-95. Background neutrons and gamma rays limit the system sensitivity at present, but improvements appear feasible that will permit deduction of leveldensities and in some cases widths of a number of neutron-rich nuclides that are inaccessible to study by any other probe. The data bear on optical models and neutron cross sections for such nuclides

  19. Linear accelerator for tritium production

    For many years now, Los Alamos National Laboratory has been working to develop a conceptual design of a facility for accelerator production of tritium (APT). The APT accelerator will produce high energy protons which will bombard a heavy metal target, resulting in the production of large numbers of spallation neutrons. These neutrons will be captured by a low-Z target to produce tritium. This paper describes the latest design of a room-temperature, 1.0 GeV, 100 mA, cw proton accelerator for tritium production. The potential advantages of using superconducting cavities in the high-energy section of the linac are also discussed and a comparison is made with the baseline room-temperature accelerator. copyright 1996 American Institute of Physics

  20. Linear accelerator for tritium production

    For many years now, Los Alamos National Laboratory has been working to develop a conceptual design of a facility for accelerator production of tritium (API). The APT accelerator will produce high energy protons which will bombard a heavy metal target, resulting in the production of large numbers of spallation neutrons. These neutrons will be captured by a low-Z target to produce tritium. This paper describes the latest design of a room-temperature, 1.0 GeV, 100 mA, cw proton accelerator for tritium production. The potential advantages of using superconducting cavities in the high-energy section of the linac are also discussed and a comparison is made with the baseline room-temperature accelerator

  1. accelerating cavity

    On the inside of the cavitytThere is a layer of niobium. Operating at 4.2 degrees above absolute zero, the niobium is superconducting and carries an accelerating field of 6 million volts per metre with negligible losses. Each cavity has a surface of 6 m2. The niobium layer is only 1.2 microns thick, ten times thinner than a hair. Such a large area had never been coated to such a high accuracy. A speck of dust could ruin the performance of the whole cavity so the work had to be done in an extremely clean environment.

  2. Particle accelerators and scientific culture

    A historical review of fifty years of physics around particle accelerators, from the first nuclear reactions produced by beams of artificially accelerated particles to the large multinational projects now under discussion. The aim is to show how our description of natural phenomena has been shaped by advances in theoretical understanding, the development of new techniques, and the characters of men. Large use has been made of quotations from many of the scientists involved. (Auth.)

  3. Particle accelerators and scientific culture

    A historical review of fifty years of physics around particle accelerators, from the first nuclear reactions produced by beams of artificially accelerated particles to the large multinational projects now under discussion. The aim is to show how the description of natural phenomena has been shaped by advances in theoretical understanding, the development of new techniques, and the characters of men. Large use has been made of quotations from many of the scientists involved. (Auth.)

  4. The Beta Tech electron accelerator

    After describing the background of the Swedish Electron Sterilization Centre, the proposed linear accelerator sterilization plant is outlined. The accelerator will produce electrons of energy 10 MeV and a beam power of 30 KW. The handling system, control and identification systems are also described. Documentation will be designed around a bar code system on line to a computer. The various uses of dosimetry in plant performance and process control are described. (U.K.)

  5. Stochastic modeling of Lagrangian accelerations

    Reynolds, Andy

    2002-11-01

    It is shown how Sawford's second-order Lagrangian stochastic model (Phys. Fluids A 3, 1577-1586, 1991) for fluid-particle accelerations can be combined with a model for the evolution of the dissipation rate (Pope and Chen, Phys. Fluids A 2, 1437-1449, 1990) to produce a Lagrangian stochastic model that is consistent with both the measured distribution of Lagrangian accelerations (La Porta et al., Nature 409, 1017-1019, 2001) and Kolmogorov's similarity theory. The later condition is found not to be satisfied when a constant dissipation rate is employed and consistency with prescribed acceleration statistics is enforced through fulfilment of a well-mixed condition.

  6. New type of collective accelerator

    A collective accelerator based on magnetically confined plasma rings is described. Typical rings which have been produced and which have 10 kJ magnetic energy and 0.1 to 10 coulombs of nuclei are predicted to be accelerated magnetically to 10 MJ or higher in acceleration lengths of 100 m if the final power delivered to the ring is 1012 W. Applications are discussed of current drive in Tokamak fusion reactions, fueling and heating magnetic fusion reactors, transuranic element synthesis, and, for focused rings, a high energy density driver for inertial confinement fusion

  7. Sensitivity of radioactive nuclide leaching rate under the sub-surface disposal

    In order to dispose of radioactive wastes generated from and stored in JAEA in the sub-surface disposal facility, JAEA has studied the safety assessment of sub-surface disposal considering likely scenario and less-likely scenario. Leaching rate of radionuclide from radioactive wastes to permeation water in sub-surface disposal facility is important parameter in the safety assessment because radionuclides contained in activated metal are released to permeation water by the corrosion of metal. In this report, we studied sensitivity of radionuclide leaching rate from radioactive wastes in the safety assessment of sub-surface disposal. As a result, it is confirmed that the dose due to Cl-36 which is dominant nuclide at groundwater scenario in the safety assessment is sensitive to radionuclide leaching rate from radioactive wastes, but the dose due to Nb-94 which is dominant nuclide at tunnel excavation scenario in the assessment is not sensitive to radionuclide leaching rate but to distribution coefficients of engineered barrier. (author)

  8. Investigations on Cerenkov effect application of β-radiating nuclides in transparent media

    Charged particles with higher energies are able to generate photons in transparent media by means of the Cerenkov effect. This can be used to detect β-radiading nuclides with more than 0.26 MeV maximum energy in aqueous solutions. Counter gain and impulse hight-spectra for different nuclides can be determined by means of a specially designed counter. The counter consists of two coincidence photomultipliers. It is possible to determine quantitatively β-radiating impurities in high activity γ-radiating solution. Further the possibility was examined to acquire spatial β-activity distributions by means of the Cerenkov effect. This yields a resolution, smaller than 1.3 mm for 32P and for superficially located sources. The intensity decreases exponentially with the depth (half-value-depth about 0.5 mm). With this the method is better than a semiconductor needle probe and has the advantage of a selective resolution of the surface distribution without a disturbing γ-influence, when compared with the conventional autoradiography. Advantageous applications of several Cerenkov counters in radiochemistry and nuclear medicine are described. (orig./HP)

  9. Finite medium Green's function solutions to nuclide transport in porous material

    It is important to develop mathematical models to estimate the release of buried radioactive waste to the biosphere and its potential impact on man. A necessary link in simulating this process is a model that accurately represents the subsurface transport. Among the analytical techniques used to predict the transport of nuclides in porous materials is the Green's function approach, i.e., the response characteristics of a geologic pathway to an impulse function input. To data, the analyses all have set the boundary conditions needed to solve the 1-D transport equation as though each pathway were infinite in length. This paper critically examines the effects that the infinite pathway assumption has on Green's function models of nuclide transport in porous media. It treats the more difficult problem of obtaining suitable Green's functions for finite pathways whose dimensions may not be much greater than the diffusion length. Such pathways may occur in multipath representations of a waste repository. Because of the ease of treatment of stacked pipes and their more accurate representation of short pathways, finite medium Green's functions represent an improvement over current waste transport models and extend the range of applicability of the Green's function approach to solving radionuclide transport problems

  10. Declaration and checking of nuclide inventory in radioactive wastes within the framework of waste flow surveillance

    In Mai of 1989 the Federal Republic of Germany issued its 'Guideline on the Control of Radioactive Wastes with Negligible Heat Generation' (the so-called Waste Control Guideline) (1). With special regard to the safety of the intermediate waste storage and final disposal, the purpose of this guideline is to specify surveillance measures for all steps during waste removal such that the amount of waste, its location and state of treatment can be determined at all times. This guideline calls for a continual surveillance of the waste, from the time of its creation to its disposal. This surveillance entails the recording of specific safety related waste characteristics and the radioactivity of certain key nuclides. Either the originator of the waste or a third party on his behalf shall document and process these data and information in such a way that the information required by the proper authority can be presented without undue delay. To help in implementing the guideline specifically for nuclear power plants, a modular PC code, AVK, was developed (AVK is the German acronym for 'wasteflow surveillance and control'). An important part of this code is the module MOPRO which treats the declaration and checking of the nuclide inventory in individual nuclear wastes. The object of this presentation is to describe the basics of this specific code module

  11. Bernal liquid drop - alpha particle models of some heavy magic number nuclides

    Full text: Models of the bond structures of nickel 56, strontium 88, tin 120, cerium 140, lead 208 and uranium 240 nuclides based on Bernal's models of dense liquid drops, show good agreement between the binding energy data and shell structures when alpha particles are considered to be the densely packed hard spheres, of Bernal's models. These models, of the time-averaged structures of several closed shell nuclides have been developed as pedagogical aids for conceptualising some of the major aspects of nuclear matter and energy. These concepts include nuclear shape, size, charge density, quadrupole moment, viscosity, binding energy, coulomb repulsion, energy levels, magic numbers, shells and subshells; nucleon separation, bonding, pairing and clustering; nucleosynthesis, radioactivity and fission. The models discussed are based on those proposed by Bernal to account for the properties of normal liquids. Bernal's models have also been extended by others to explain the nature of metallic glasses considered as super cooled liquids. In Bernal's tetrahedral model of a normal liquid drop, a hard sphere representing an atom, ion, or molecule is added at whatever available position is closed to the centre of the existing cluster of spheres so that the densest possible configuration is created. Accordingly, two spheres form a dumbbell, three spheres form a triangle and four spheres form a tetrahedron and so on

  12. DRENA: A model for the transport of nuclides in drainage slopes

    This report presents documentation and a user's manual for program DRENA, a mathematical model of nuclides transfer in simple slopes and sections of a drainage catchment. Mathematical equations and physical principles utilized to develop the code are presented in section 2. The flowchart and some mathematic and numerical details are presented in Section 3. Section 4 presents an overview of how problems should be set up to properly use the code as well as the detailed input instructions and output results formats. One example problem, including sample input data sets and output data, are presented in Section 5. The complete program listings including comments are presented in the Appendices. Nuclides are assumed to enter the catchment via atmospheric deposition and then carried by the water runoff and the dragged sediments. The desorption/adsorption dynamics between water and sediments are considered to be in the equilibrium given by a Kd parameter, a distribution coefficient. Codell's and Einstein expressions for the caudal and concentration of dragged sediments are utilized. (Author)

  13. DRENA: A model for the transport of nuclides in drainage slopes

    This report presents documentation and a user's manual for program DRENA, a mathematical model of nuclides transfer in simple slopes and sections of a drainage catchment. Mathematical equations and physical principles utilized to develop the code are presented in section 2. The flowchart and some mathematic and numerical details are presented in Section 3. Section 4 presents an overview of how problems should be set up to properly use the code as well as the detailed input instructions and output results formats. One example problem, including sample input data sets and output data, are presented in Section 5. The complete program listings including comments are presented in the Appendices. Nuclides are assumed to enter the catchment via atmospheric deposition and then carried by the water runoff and the dragged sediments. The desorption/adsorption dynamics between water and sediments are considered to be in the equilibrium given by a Kd parameter, a distribution coefficient. Codell's and Einstein expressions for the caudal and concentration of dragged sediments are utilized. (Author) 36 refs

  14. Sand residence times of one million years in the Namib Sand Sea from cosmogenic nuclides

    Vermeesch, P.; Fenton, C. R.; Kober, F.; Wiggs, G. F. S.; Bristow, C. S.; Xu, S.

    2010-12-01

    The Namib Sand Sea is one of the world's oldest and largest sand deserts, yet little is known about the source of the sand in this, or other large deserts. In particular, it is unclear whether the sand is derived from local sediment or comes from remote sources. The relatively uniform appearance of dune sands and low compositional variability within dune fields make it difficult to address this question. Here we combine cosmogenic-nuclide measurements and geochronological techniques to assess the provenance and migration history of sand grains in the Namib Sand Sea. We use U-Pb geochronology of detrital zircons to show that the primary source of sand is the Orange River at the southern edge of the Namib desert. Our burial ages obtained from measurements of the cosmogenic nuclides 10Be, 26Al and 21Ne suggest that the residence time of sand within the sand sea is at least one million years. We therefore conclude that, despite large climatic changes in the Namib region associated with Quaternary glacial-interglacial cycles, the area currently occupied by the Namib Sand Sea has never been entirely devoid of sand during the past million years.

  15. The standard facility for nuclide activity measurement by 4πγ high pressure ionization chamber

    The standard consists of 4πγ pressurized ionization chambers (IC/2C(1.0 MPa) and IG12/A20(2.0 MPa), small current measurement system, standard bottles, one set of long-live reference sources (226Ra), and lead shields. It has the following advantages: 1) long-term stability less than 0.1% per year; 2) fast speed for activity measurement; 3) Do allowing the direct measurement activity of solutions in ampoules; 4) permit measurement over a long range of activity (104-1010 Bq). For short-live nuclides, it is necessary to know the efficiency of the ionization chamber. The calibration factors can be calculated according to the efficiency curve and the probability of γ-ray emission. The calibration factors of some nuclides are calculated and the deviation of the calculation factors from experiment is less than +-3%. The half-life of 99Tcm is measured, the result is 6.0053 +- 0.0018 h

  16. Study on fitness functions of genetic algorithm for dynamically correcting nuclide atmospheric diffusion model

    Background: In radioactive nuclides atmospheric diffusion models, the empirical dispersion coefficients were deduced under certain experiment conditions, whose difference with nuclear accident conditions is a source of deviation. A better estimation of the radioactive nuclide's actual dispersion process could be done by correcting dispersion coefficients with observation data, and Genetic Algorithm (GA) is an appropriate method for this correction procedure. Purpose: This study is to analyze the fitness functions' influence on the correction procedure and the forecast ability of diffusion model. Methods: GA, coupled with Lagrange dispersion model, was used in a numerical simulation to compare 4 fitness functions' impact on the correction result. Results: In the numerical simulation, the fitness function with observation deviation taken into consideration stands out when significant deviation exists in the observed data. After performing the correction procedure on the Kincaid experiment data, a significant boost was observed in the diffusion model's forecast ability. Conclusion: As the result shows, in order to improve dispersion models' forecast ability using GA, observation data should be given different weight in the fitness function corresponding to their error. (authors)

  17. An analysis of the correlation between dust storms in Korea and {sup 137}Cs nuclide concentration

    Choi, Soo-won; Kim, Jeong-hun; Shin, Sang-hwa; Hwang, Joo-ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2008-05-15

    Dust storms occur in Korea during spring time when fine dust is blown in from the far western regions of western China and Mongolia. A fine powdery dust is blown up into the sky and enters the upper reaches of the atmosphere where it is carried easterly across China then slowly falls to the ground on the Korean peninsula and Japan. The dust originates mostly in the Gobi dessert of China, as well as the yellow earth regions in the middle and upper streams of the Yellow river in China. Previous studies on dust storms have been limited to following or estimating their courses, distribution and frequency, or distribution of the heavy metals they transmit. However, since radionuclides exist in the dust, they must also exist in the dust storms. In this study, we analyzed the correlation of :1{sup 37}Cs nuclide concentration based on a count of annual dust storm occurrence in the city of Suwon, South Korea and assessed seasonal differences of {sup 137}Cs nuclide concentration.

  18. Laser driven particle acceleration

    This dissertation summarizes the last ten years of research at the Laboratory of Applied Optics on laser-plasma based electron acceleration. The main result consists of the development and study of a relativistic electron source with unique properties: high energy (100-300 MeV) in short distances (few millimeters), mono-energetic, ultra-short (few fs), stable and tunable. The manuscript describes the steps that led to understanding the physics, and then mastering it in order to produce this new electron source. Non linear propagation of the laser pulse in the plasma is first presented, with phenomena such as non linear wakefield excitation, relativistic and ponderomotive self-focusing in the short pulse regime, self-compression. Acceleration and injection of electrons are then reviewed from a theoretical perspective. Experimental demonstrations of self-injection in the bubble regime and then colliding pulse injection are then presented. These experiments were among the first to produce monoenergetic, high quality, stable and tunable electron beams from a laser-plasma accelerator. The last two chapters are dedicated to the characterization of the electron beam using transition radiation and to its applications to gamma radiography and radiotherapy. Finally, the perspectives of this research are presented in the conclusion. Scaling laws are used to determine the parameters that the electron beams will reach using peta-watt laser systems currently under construction. (author)

  19. Electron Accelerator Facilities

    Lecture presents main aspects of progress in development of industrial accelerators: adaptation of accelerators primary built for scientific experiments, electron energy and beam power increase in certain accelerator constructions, computer control system managing accelerator start-up, routine operation and technological process, maintenance (diagnostics), accelerator technology perfection (electrical efficiency, operation cost), compact and more efficient accelerator constructions, reliability improvement according to industrial standards, accelerators for MW power levels and accelerators tailored for specific use

  20. Hardware Accelerated Simulated Radiography

    Laney, D; Callahan, S; Max, N; Silva, C; Langer, S; Frank, R

    2005-04-12

    We present the application of hardware accelerated volume rendering algorithms to the simulation of radiographs as an aid to scientists designing experiments, validating simulation codes, and understanding experimental data. The techniques presented take advantage of 32 bit floating point texture capabilities to obtain validated solutions to the radiative transport equation for X-rays. An unsorted hexahedron projection algorithm is presented for curvilinear hexahedra that produces simulated radiographs in the absorption-only regime. A sorted tetrahedral projection algorithm is presented that simulates radiographs of emissive materials. We apply the tetrahedral projection algorithm to the simulation of experimental diagnostics for inertial confinement fusion experiments on a laser at the University of Rochester. We show that the hardware accelerated solution is faster than the current technique used by scientists.

  1. Accelerator research studies

    The Accelerator Research Studies program at the University of Maryland, sponsored by the Department of Energy under contract number AC05-85ER40216-8, is currently in the third year of its three-year funding cycle. This Renewal Proposal requests DOE support for the next three-year period from June 1, 1991 to May 31, 1994. It documents the progress made during the past year and outlines the proposed research program for the next three years. The program consisted of the following three tasks: Task A, ''Study of Transport and Longitudinal Compression of Intense, High-Brightness Beams,'' Task B, ''Study of Collective Ion Acceleration by Intense Electron Beams and Pseudospark Produced High Brightness Electron Beams,'' Task C, ''Study of a Gyroklystron High-Power Microwave Source for Linear Colliders.'' These tasks will be discussed in this paper

  2. Accelerator research studies

    The Accelerator Research Studies program at the University of Maryland, sponsored by the Department of Energy under grant number DE-FG05-91ER40642, is currently in the second year of a three-year funding cycle. The program consists of the following three tasks: TASK A, ''Study of Transport and Longitudinal Compression of Intense, High-Brightness Beams,'' (P.I., M. Reiser); TASK B, ''Study of Collective Ion Acceleration by Intense Electron Beams and Pseudospark Produced High Brightness Electron Beams,'' (Co-P.I.'s, W.W. Destler, M. Reiser, M.J. Rhee, and C.D. Striffler); TASK C, ''Study of a Gyroklystron High-Power Microwave Source for Linear Colliders,'' (Co-P.I.'s, V.L. Granatstein, W. Lawson, M. Reiser, and C.D. Striffler). In this report we document the progress that has been made during the past year for each of the three tasks

  3. Accelerator research studies

    The Accelerator Research Studies program at the University of Maryland, sponsored by the Department of Energy under grant number DE-FG05-91ER40642, is currently in the first year of a three-year funding cycle. The program consists of the following three tasks: TASK A, Study of Transport and Longitudinal Compression of Intense, High-Brightness Beams, TASK B, Study of Collective Ion Acceleration by Intense Electron Beams and Pseudospark Produced High Brightness Electron Beams; TASK C, Study of a Gyroklystron High-power Microwave Source for Linear Colliders. In this report we document the progress that has been made during the past year for each of the three tasks

  4. Advanced medical accelerator design

    This report describes the design of an advanced medical facility dedicated to charged particle radiotherapy and other biomedical applications of relativistic heavy ions. Project status is reviewed and some technical aspects discussed. Clinical standards of reliability are regarded as essential features of this facility. Particular emphasis is therefore placed on the control system and on the use of technology which will maximize operational efficiency. The accelerator will produce a variety of heavy ion beams from helium to argon with intensities sufficient to provide delivered dose rates of several hundred rad/minute over large, uniform fields. The technical components consist of a linac injector with multiple PIG ion sources, a synchrotron and a versatile beam delivery system. An overview is given of both design philosophy and selected accelerator subsystems. Finally, a plan of the facility is described

  5. Decay Study for the very Neutron-Rich Sn Nuclides, $^{135-140}$Sn Separated by Selective Laser Ionization

    2002-01-01

    %IS378 %title\\\\ \\\\ In this investigation, we wish to take advantage of chemically selective laser ionization to separate the very-neutron-rich Sn nuclides and determine their half-lives and delayed-neutron branches (P$_{n}$) using the Mainz $^{3}$He-delayed neutron spectrometer and close-geometry $\\gamma$-ray spectroscopy system. The $\\beta$-decay rates are dependent on a number of nuclear structure factors that may not be well described by models of nuclear structure developed for nuclides near stability. Determination of these decay properties will provide direct experimental data for r-process calculations and test the large number of models of nuclear structure for very-neutron rich Sn nuclides now in print.

  6. Accelerator system and method of accelerating particles

    Wirz, Richard E. (Inventor)

    2010-01-01

    An accelerator system and method that utilize dust as the primary mass flux for generating thrust are provided. The accelerator system can include an accelerator capable of operating in a self-neutralizing mode and having a discharge chamber and at least one ionizer capable of charging dust particles. The system can also include a dust particle feeder that is capable of introducing the dust particles into the accelerator. By applying a pulsed positive and negative charge voltage to the accelerator, the charged dust particles can be accelerated thereby generating thrust and neutralizing the accelerator system.

  7. Muon acceleration in cosmic-ray sources

    Many models of ultra-high energy cosmic-ray production involve acceleration in linear accelerators located in gamma-ray bursts, magnetars, or other sources. These transient sources have short lifetimes, which necessitate very high accelerating gradients, up to 1013 keV cm–1. At gradients above 1.6 keV cm–1, muons produced by hadronic interactions undergo significant acceleration before they decay. This muon acceleration hardens the neutrino energy spectrum and greatly increases the high-energy neutrino flux. Using the IceCube high-energy diffuse neutrino flux limits, we set two-dimensional limits on the source opacity and matter density, as a function of accelerating gradient. These limits put strong constraints on different models of particle acceleration, particularly those based on plasma wake-field acceleration, and limit models for sources like gamma-ray bursts and magnetars.

  8. Identification of artificial gamma-emitting nuclides using a scintillator-based gamma-ray spectral logging system

    The standard spectral gamma ray logging system used at the Nevada Test Site (NTS) contains a large sodium iodide detector which provides high efficiency but low energy resolution. To enhance the capabilities of this system for identifying artificial gamma-emitting nuclides, I developed and implemented a simple procedure for extracting artificial components from low-resolution gamma-ray spectra. This procedures uses three bias spectra, developed by a consultant using numerical modeling, representing the spectral response of the downhole instrument to naturally occurring potassium, uranium and thorium family gamma rays in a large-diameter air-filled borehole. To extract the artificial spectral components, the three basis spectra are first scaled to the recorded field spectrum using the usual spectral windows for K, U and Th; these windows bracket the photopeaks at 1.46, 1.76 and 2.61 MeV. Since most of the contribution from artificial nuclides will fall below 1.26 MeV (the lower limit of the potassium window) this scaling process should be insensitive to the presence of artificial nuclides. The scaled basis spectra are then subtracted from the field data, leaving a residual spectrum consisting of noise plus the contribution of any artificial gamma-emitting nuclides. This process is repeated for each spectrum in the log, or the spectra can be accumulated over any desired depth range for better statistics. Rather than inspect each spectrum visually, a parameter can be computed which indicates the presence of artificial nuclides; this parameter can be plotted along with the usual K, U and Th concentration estimates as a function of depth. These techniques have been used successfully on field data and provide us with an inexpensive screening tool to detect artificial nuclides along boreholes. 11 refs., 6 figs

  9. A study on the stochastic model for nuclide transport in the fractured porous rock using continuous time Markov process

    As a newly approaching model, a stochastic model using continuous time Markov process for nuclide decay chain transport of arbitrary length in the fractured porous rock medium has been proposed, by which the need for solving a set of partial differential equations corresponding to various sets of side conditions can be avoided. Once the single planar fracture in the rock matrix is represented by a series of finite number of compartments having region wise constant parameter values in them, the medium is continuous in view of various processes associated with nuclide transport but discrete in medium space and such geologic system is assumed to have Markov property, since the Markov process requires that only the present value of the time dependent random variable be known to determine the future value of random variable, nuclide transport in the medium can then be modeled as a continuous time Markov process. Processes that are involved in nuclide transport are advective transport due to groundwater flow, diffusion into the rock matrix, adsorption onto the wall of the fracture and within the pores in the rock matrix, and radioactive decay chain. The transition probabilities for nuclide from the transition intensities between and out of the compartments are represented utilizing Chapman-Kolmogorov equation, through which the expectation and the variance of nuclide distribution for each compartment or the fractured rock medium can be obtained. Some comparisons between Markov process model developed in this work and available analytical solutions for one-dimensional layered porous medium, fractured medium with rock matrix diffusion, and porous medium considering three member nuclide decay chain without rock matrix diffusion have been made showing comparatively good agreement for all cases. To verify the model developed in this work another comparative study was also made by fitting the experimental data obtained with NaLS and uranine running in the artificial fractured

  10. Cosmogenic nuclide production rates as a function of latitude and altitude calculated via a physics based model and excitation functions

    Argento, D.; Reedy, R. C.; Stone, J. O.

    2012-12-01

    Cosmogenic nuclides have been used to develop a set of tools critical to the quantification of a wide range of geomorphic and climatic processes and events (Dunai 2010). Having reliable absolute measurement methods has had great impact on research constraining ice age extents as well as providing important climatic data via well constrained erosion rates, etc. Continuing to improve CN methods is critical for these sciences. While significant progress has been made in the last two decades to reduce uncertainties (Dunai 2010; Gosse & Phillips 2001), numerous aspects still need to be refined in order to achieve the analytic resolution desired by glaciologists and geomorphologists. In order to investigate the finer details of the radiation responsible for cosmogenic nuclide production, we have developed a physics based model which models the radiation cascade of primary and secondary cosmic-rays through the atmosphere. In this study, a Monte Carlo method radiation transport code, MCNPX, is used to model the galactic cosmic-ray (GCR) radiation impinging on the upper atmosphere. Beginning with a spectrum of high energy protons and alpha particles at the top of the atmosphere, the code tracks the primary and resulting secondary particles through a model of the Earth's atmosphere and into the lithosphere. Folding the neutron and proton flux results with energy dependent cross sections for nuclide production provides production rates for key cosmogenic nuclides (Argento et al. 2012, in press; Reedy 2012, in press). Our initial study for high latitude shows that nuclides scale at different rates for each nuclide (Argento 2012, in press). Furthermore, the attenuation length for each of these nuclide production rates increases with altitude, and again, they increase at different rates. This has the consequence of changing the production rate ratio as a function of altitude. The earth's geomagnetic field differentially filters low energy cosmic-rays by deflecting them away

  11. Technology of magnetically driven accelerators

    The marriage of Induction Linac technology with Nonlinear Magnetic Modulators has produced some unique capabilities. It appears possible to produce electron beams with average currents measured in amperes, at gradients exceeding 1 MeV/meter, and with power efficiencies approaching 50%. A 2 MeV, 5 kA electron accelerator has been constructed at the Lawrence Livermore National Laboratory (LLNL) to demonstrate these concepts and to provide a test facility for high brightness sources. The pulse drive for the accelerator is based on state-of-the-art magnetic pulse compressors with very high peak power capability, repetition rates exceeding a kilohertz and excellent reliability. 8 figs., 1 tab

  12. Implications of two Holocene time-dependent geomagnetic models for cosmogenic nuclide production rate scaling

    Lifton, Nathaniel

    2016-01-01

    The geomagnetic field is a major influence on in situ cosmogenic nuclide production rates at a given location (in addition to atmospheric pressure and, to a lesser extent, solar modulation effects). A better understanding of how past fluctuations in these influences affected production rates should allow more accurate application of cosmogenic nuclides. As such, this work explores the cosmogenic nuclide production rate scaling implications of two recent time-dependent spherical harmonic geomagnetic models spanning the Holocene. Korte and Constable (2011, Phys. Earth Planet. Inter.188, 247-259) and Korte et al. (2011, Earth Planet. Sci. Lett. 312, 497-505) recently updated earlier spherical harmonic paleomagnetic models with new paleomagnetic data from sediment cores in addition to new archeomagnetic and volcanic data. These updated models offer improved resolution and accuracy over the previous versions, in part due to increased temporal and spatial data coverage. In addition, Pavón-Carrasco et al. (2014, Earth Planet. Sci. Lett. 388, 98-109) developed another time-dependent spherical harmonic model of the Holocene geomagnetic field, based solely on archeomagnetic and volcanic paleomagnetic data from the same underlying paleomagnetic database as the Korte et al. models, but extending to 14 ka. With the new models as input, trajectory-traced estimates of effective vertical cutoff rigidity (RC - the standard method for ordering cosmic ray data) yield significantly different time-integrated scaling predictions when compared to each other and to results using the earlier models. In addition, predictions of each new model using RC are tested empirically using recently published production rate calibration data for both 10Be and 3He, and compared to predictions using corresponding time-varying geocentric dipolar RC formulations and a static geocentric axial dipole (GAD) model. Results for the few calibration sites from geomagnetically sensitive regions suggest that the

  13. MARMER, Point-Kernel Shielding Calculation with Nuclide Concentrations from ORIGEN-S

    1 - Description of program or function: MARMER is a point-kernel shielding code which can be used to calculate the dose rate, energy absorption rate, energy flux or gamma-ray flux due to several sources at any point in a complex geometry. The geometry is described by the MARS geometry system which makes use of Combinatorial Geometry and an array repeating feature. Source spectra may be defined in several ways including an option to read a binary file containing nuclide concentrations, which has been calculated by ORIGEN-S. Therefore, MARMER makes use of a nuclide data library containing half life times, decay energies and gamma yields for over 1000 nuclides. To facilitate the use of ORIGEN-S, a pre-processor named PREORI is included for simple irradiation and decay problems. The spatial description of the source may be done in cartesian, cylindrical and spherical coordinates and the source strength as a function of the distance along the coordinate axes may be done in many different ways. Several sources with different spectra may be treated simultaneously. As many calculational points as needed may be defined. 2 - Method of solution: The source volume is divided into volume- elements and the source energy distribution is divided into energy groups. The un-scattered gamma-ray flux is calculated by an exponential attenuation kernel, which is integrated over all source volume-elements and all energy group by use of a Monte Carlo integration method. The flux is then converted to the requested detector response by use of conversion factors, which are read from a binary file. Scattered gamma-rays are accounted for by buildup factors, which are tabulated in another binary file containing dose rate equivalent and energy absorption buildup factors. Buildup factors for each shield are calculated by interpolating for the effective atomic number of the shield. For multilayered shields the buildup factor of one shield or the methods of Kitazume or Broder may be used. Although

  14. DAMD code for producing nuclear data library of fission products

    Computer codes DAMD, TACA and TREE have been developed. The code DAMD produces a nuclear data library from ENDF/B format library for the computer code DCHAIN which analyzes buildup and decay of fission products. The code TACA punches out and prints out the contents of the nuclear data library for DCHAIN. The code TREE prints out the decay schemes of the nuclides contained in the library. (auth.)

  15. PRODUCTION AND APPLICATIONS OF NEUTRONS USING PARTICLE ACCELERATORS

    David L. Chichester

    2009-11-01

    Advances in neutron science have gone hand in hand with the development and of particle accelerators from the beginning of both fields of study. Early accelerator systems were developed simply to produce neutrons, allowing scientists to study their properties and how neutrons interact in matter, but people quickly realized that more tangible uses existed too. Today the diversity of applications for industrial accelerator-based neutron sources is high and so to is the actual number of instruments in daily use is high, and they serve important roles in the fields where they're used. This chapter presents a technical introduction to the different ways particle accelerators are used to produce neutrons, an historical overview of the early development of neutron-producing particle accelerators, a description of some current industrial accelerator systems, narratives of the fields where neutron-producing particle accelerators are used today, and comments on future trends in the industrial uses of neutron producing particle accelerators.

  16. Accelerator Applications Support Nuclear Science and Technology

    Accelerators are machines that use high voltages to produce artificial radiation in the form of beams of energetic particles. They are more versatile and safer than radioactive sources because the energy can be varied, and when the accelerator is turned off, so is the radiation. Accelerators are used for diverse applications such as to treat cancer, analyse artwork and old artefacts, clean up waste effluent gases, produce computer chips and map the structure of proteins. Accelerator technology makes a valuable contribution to the technological progress of a country, which in turn can also contribute to a country’s economic development

  17. Accelerator mass spectrometry of actinides and the search for superheavy elements

    In the 1960s nuclear shell model calculations indicated an increased stability of superheavy closed-shell nuclides beyond any known species. This region was quickly nicknamed island of stability', and half-lives up to 109 years were predicted for some nuclides. Assuming their presence in the Early Solar System, the predicted half-lives would be sufficiently long to find traces of these nuclides in natural materials today. Within the last decades numerous experiments - utilizing different measurement techniques - were conducted to detect superheavy elements (SHEs) in nature - all with negative results. Appreciable technical progress in Accelerator Mass Spectrometry (AMS) within recent years triggered new attempts to find SHEs in natural materials. AMS is considered to be the 'technique of choice' for the detection of long-lived radionuclides at ultra-low abundances. The outstanding selectivity of AMS allowed the investigation of chemically untreated natural samples, preventing a priori an unintended separation of SHEs in chemical preparations, which are required for other measurement techniques. For the first time the 'Vienna Environmental Research Accelerator' (VERA) facility was set up for AMS measurements in the mass range of A = 288-300 amu. Altogether 30 nuclides in the vicinity of the 'island of stability' were investigated. Sample material extracted from natural ores containing Pb or Bi and nuggets of Pt and Au was used in these measurements. Since no unambiguous events were detected, upper limits for the abundance of those nuclides within the sample matrix in the range of 10-12 to 10-15 (relative to the carrier matrix atoms) could be established. When the SHE project started at VERA, the detection of a long-lived superheavy ion species with A = 292 in thorium was reported by the group of Marinov et al. in Jerusalem performed by means of inductively coupled plasma sector field mass spectrometry (ICPSF-MS). The group also reported on the detection of four long

  18. An attempt to concentrate new natural spontaneously fissioning nuclide from geothermal brine of Cheleken peninsula

    In order to concentrate a new not yet identified spontaneously fissioning nuclide (NSFN) discovered in geothermal brines of Cheleken Peninsula various heterogenic processes were used in the brine-solid phase systems (ionites, inorganic sorbents, metals, etc.). Besides, natural inorganic collectors selected on the borehole mouths were analysed. Concentrates with approx. 105 enrichment coefficient have been obtained. It is shown that NSFN has a low degree of coprecipitation with sulfides and metal hydroxydes. It is not reduced by neither iron, nor by aluminium, is sorbed on cationites and anionites. The results obtained allow one to draw a conclusion that NSFN is not an isotope of transuranium elements. NSFN is near by its chemical properties to gold and mercury. According to the experimental data, its standard electrode potential equals (1.3+-0.2) B

  19. Database for radionuclide transport in the biosphere: nuclide specific and geographic data for northern Switzerland

    The biosphere model is the final link in the chain of radionuclide transport models, used for radiation dose calculations from high-level waste repositories. This report presents the data needed for biosphere calculations and discusses them where necessary. The first part is dedicated to the nuclide specific parameters like distribution coefficients (water -soil), concentration ratios (soil - plant) and distribution factors (for milk, meat, etc.) which are reported in the literature. The second part contains the choice of regions, their division into compartments and the discussion of nutritional habits for man and animals. At the end a theoretical human population for each region is estimated based on the consumption rates and on the yield of agricultural products, assuming an autonomous nutrition. (author)

  20. Integral test on activation cross section of tag gas nuclides using fast neutron spectrum fields

    Activation cross sections of xenon and krypton isotopes were evaluated as tag gases to identify capsule rupture in liquid metal cooled fast reactors. The accuracy of the activation cross sections was investigated with several tag gas samples irradiated in the standard neutron field of JOYO and YAYOI reactors. Comparing the measured radioactivities and calculated values using YAYOI neutron fluence and activation cross section processed from the JENDL(Japanese Evaluated Nuclear Data Library)-3.2 cross section library, yielded C/E values of approximately 0.86 to 2.6 for tag gas nuclides. The discrepancy between calculation and measurement appears due to the cross section uncertainty. This study confirmed the present accuracy of tag gas activation cross sections. (author)

  1. Calculations of thermal-reactor spent-fuel nuclide inventories and comparisons with measurements

    Comparisons with integral measurements have demonstrated the accuracy of CINDER codes and libraries in calculating aggregate fission-product properties, including neutron absorption, decay power, and decay spectra. CINDER calculations have, alternatively, been used to supplement measured integral data describing fission-product decay power and decay spectra. Because of the incorporation of the extensive actinide library and the use of ENDF/B-V data, it is desirable to compare the inventory of individual nuclides obtained from tandem EPRI-CELL/CINDER-2 calculations with those determined in documented benchmark inventory measurements of spent reactor fuel. The development of the popular 148Nd burnup measurement procedure is outlined, and areas of uncertainty in it and lack of clarity in its interpretation are indicated. Six inventory samples of varying quality and completeness are examined. The power histories used in the calculations have been listed for other users

  2. Calibration of nuclides by gamma-gamma sum peak coincidence counting

    The feasibility of extending sum peak coincidence counting to the direct calibration of gamma-ray emitters having particular decay schemes was investigated, also checkings of the measurement accuracy, by comparing with more precise beta-gamma coincidence counting have been performed. New theoretical studies and experiments were developed, demonstrating the reliability of the procedure. Uncertainties of less than one percent were obtained when certain radioactive sources were measured. The application of the procedure to 60Co, 22Na, 47Ca and 148Pm was studied. Theoretical bases of sum peak coincidence counting were set in order to extend it as an alternative method for absolute activity determination. In this respect, theoretical studies were performed for positive and negative beta decay, and electron capture, either accompanied or unaccompanied by coincident gamma rays. They include decay schemes containing up to three daughter nuclide excited levels, for different geometrical configurations. Equations are proposed for a possible generalization of the procedure. (M.E.L.)

  3. Towards a magnetic field stabilization at ISOLTRAP for high-accuracy mass measurements on exotic nuclides

    Marie-Jeanne, M; Blaum, K; Djekic, S; Dworschak, M; Hager, U; Herlert, A; Nagy, S; Savreux, R; Schweikhard, L; Stahl, S; Yazidjian, C

    2008-01-01

    The field stability of a mass spectrometer plays a crucial role in the accuracy of mass measurements. In the case of mass determination of short-lived nuclides with a Penning trap, major causes of fluctuations are temperature variations in the vicinity of the trap and pressure changes in the liquid helium cryostat of the superconducting magnet. Thus systems for the temperature and pressure stabilization of the Penning trap mass spectrometer ISOLTRAP at the ISOLDE facility at CERN have been installed. A reduction of the temperature and pressure fluctuations by at least an order of magnitude down to and has been achieved, which corresponds to a relative magnetic field change of ΔB/B=2.7×10-9 and 1.1×10-10, respectively.

  4. Radioactive nuclides in sewage sludges and problems associated with their utilisation or dumping

    In a sewage plant with radioactively contaminated sewage an accumulation of radionuclides was found in the sewage sludge. The specific activities are in inverse proportion to the water content of the sewage sludge, the dehydrated sewage sludge having the highest specific activities. The retained radionuclides seem to be firmly accumulated in the sludge. Nevertheless, they are in a form which can be utilised by plants. This was demonstrated in experiments with Trifolium Repens and Secale Cereale where the rate of absorption was 15-33% (in Ci/kg dry weight per plant: nCi/kg dry weight soil x 100). Thus there are problems associated with using radioactively contaminated sewage sludge as a fertiliser. In further experiments to extract radioactive nuclides from ashed sewage sludge it was shown that acidifying the aqueous phase results in an increase in the level of radioactivity in the eluated fractions. (author)

  5. ERRORJ: A code to process neutron-nuclide reaction cross section covariance, version 2.3

    For the evaluation of the uncertainties of nuclear parameters which are induced by uncertainties in neutron-nuclide reaction cross sections with deterministic procedures, covariance data for energy-averaged cross sections are necessary. ERRORJ is a processing code to transform cross section covariance given in the ENDF format into energy-averaged cross section covariance. ERRORJ can process the covariance data of cross sections including resonance parameters, angular and energy distributions of secondary neutrons. Since the release of the previous version, ERRORJ has been modified in order to reduce calculation time and to make it easy to incorporate ERRORJ into the NJOY code system. The version 2.3 is developed with these modifications. (author)

  6. Beta decay and delayed proton emission of a new nuclide 59Zn

    The β+-decay of a new nuclide 59Zn has been identified by β-delayed proton and γ-ray emission. Two γ-rays and 15 proton groups have been associated with the decay of 59Zn. The total proton branching ratio was measured to be (2.3 +- 0.8) x 10-4. A half-life of 210 +- 20 ms was measured for 59Zn. The superallowed β-branch to its mirror, the Jsup(π)=3/2- ground state of 59Cu, was shown to be (93 +- 3)%. Absolute log ft values for β-transitions associated with the observed delayed proton groups were calculated and an experimental β-transition strength function was obtained. (author)

  7. Adsorption of nuclides on hydrous oxides: Sorption isotherms on natural materials

    Hydrous oxides and minerals which have adsorbing groups that behave like hydrous oxides are ubiquitous components of geological formations and may dominate the adsorptive properties of the formations at conditions of natural groundwaters. An understanding of the adsorptive behavior of hydrous oxides is therefore necessary for reliable prediction of migration of nuclides through the formations. Various isotherms are derived from equilibrium ion-exchange theory for the sorption of non-hydrolyzed ions on hydrous oxides. These isotherms are compared with experimental isotherms for sorption of Cs/sup +/, Sr/sup 2+/, Eu/sup 3+/, and TcO/sub 4//sup -/ on several hydrous oxides. General features of these isotherms are predictable from ion-exchange equilibrium theory as applied to hydrous oxides. By combining isotherms for hydrous oxides with those for layer-type clay minerals, many unusual features of isotherms found on geological materials can be explained

  8. Evaluation of half-lives and average decay energies for short-lived fission product nuclides

    β-decay half-lives T1/2, average β-energies E-barβ, and average γ-energies E-barγ, which are essential for the decay heat, are calculated with use of an improved gross theory of β-decay. First, the improvement of the gross theory is explained, and then T1/2, E-barβ, and E-barγ are tabulated for β--decay nuclides with 26 < Z(proton number) < 65 and N(neutron number) < (147/92)Z + 6 except for those with small Q-value. The β-decay Q-values used in this calculation are obtained from the Wapstra-Audi mass evaluation and a mass formula newly constructed by Tachibana et al. Figures are given to indicate how the results depend on the parameters in the model. (author)

  9. Optimization of irradiation decay and counting times in nuclear activation analysis using short-lived nuclides

    This work describes a method and outlines a procedure for optim- ization of an activation analysis with respect to the experimental times, irradiation time, t(subi), decay time and counting time. The method is based on the 'minimum relative standard deviation criterion', and specially designed for the use on short-lived nuclides. A computer program, COMB1, is written in the BASIC language in order to make the calculations easier and faster. It is intended to be understandable, and easily applicable on a computer of modest size. Time and cost are important factors, especially for routine analysis on a service basis. In such cases one can often allow a controlled reduction in the analysis quality (through a higher relative standard deviation). The procedure outlined can therefore help find acceptable conditions by calculation of the 'best practical' (or reasonable) experimental time values, and the minimum number of accumulation cycles necessary to fulfil the requirements given. (Auth.)

  10. A new OECD/NEA database of nuclide compositions of spent nuclear fuel

    The SFCOMPO database of nuclide compositions of spent nuclear fuel is hosted by the OECD Nuclear Energy Agency since 2001. Since 2011, a collaborative effort led by the OECD/NEA Data Bank and Oak Ridge National Laboratory, under the guidance of the NEA Expert Group on Assay Data of Spent Nuclear Fuel, has resulted in the creation of a new enhanced relational database structure and a significant expansion of SFCOMPO, now containing experimental assay data for a wide selection of international reactor designs. This paper aims at describing the new SFCOMPO Database developed at NEA in terms of functionalities, contents and foreseen developments. This new database is expected for public release in 2014. (author)

  11. Production of cosmogenic nuclides in meteorites by primary galactic particles - Cross sections and model calculations

    Cross sections for the proton-induced production of radionuclides (40 less than or equal to A less than or equal to 60) from natural titanium, iron, and nickel were measured for proton energies from 80 to 200 MeV. The experimental data were compared with calculations according to Blann's hybrid model of nuclear reactions and to the semiempirical formulas of Rudstam and of Silberberg and Tsao. Based mainly on the new excitation functions, the production rates of cosmogenic radionuclides in meteorites by primary galactic protons were calculated. Since the interaction of primary solar and galactic particles with meteorites can be described with accuracy, the model calculations allow for a quantitative estimate of the action of secondary particles in meteorites. A method of completely describing the production of cosmogenic nuclides in meteorites that takes into account all sources of production is proposed. 51 references

  12. 222Rn and stable nuclides as natural tracers in an artificial recharge system

    Radon and stable nuclides were used as a tracer of groundwater/surface water interaction study in a artificial groundwater recharge system near Nakdong river in Korea. The 222Rn concentration at the observation well groundwater was decreased. The activity variation of each monitoring wells during short and long term experiment were 6.5-12.4 Bq/L at OBS-1, 3.8-6.8 Bq/L at OBS-2, 30.9-55.9 Bq/L at OBS-3, 5.9-25.5 Bq/L at OBS-4, 22.1-34.6 Bq/L at OBS-5 and 7.1-28.3 Bq/L at OBS-6. The 222Rn concentration of OBS-1 and 5 were decrease about 35 % but OBS-6 was increased. (author)

  13. Simulations to neutron-induced gamma ray spectra of light nuclides in TNT

    There are several factors affecting the detection of explosive or landmine using neutron-induced reactions, such as the neutron source, detector, object and surroundings. In this paper,using a system of NaI(Tl) or BGO detectors and an Am-Be neutron source, prompt gamma ray spectra from nuclides in TNT of landmine in soil are simulated by MCNP. The counts of full energy characteristic peaks of gamma rays from hydrogen, carbon, nitrogen and oxygen in TNT are related to the explosive mass. Effects of the soil moisture on the gamma-ray spectrum are studied. The ratio of full energy peak counts from nitrogen to full energy peak counts from carbon is defined. A method to use the ratio to identify explosives under water environment is proposed. (authors)

  14. Probing the nuclide {sup 180}W for neutrinoless double-electron capture exploration

    Droese, C., E-mail: c.droese@gsi.de [Institut fuer Physik, Ernst-Moritz-Arndt-Universitaet, 17487 Greifswald (Germany); Blaum, K. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Block, M. [GSI Helmholtzzentrum fuer Schwerionenforschung, Planckstrasse 1, 64291 Darmstadt (Germany); Eliseev, S. [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Herfurth, F. [GSI Helmholtzzentrum fuer Schwerionenforschung, Planckstrasse 1, 64291 Darmstadt (Germany); Minaya Ramirez, E. [Helmholtz-Institut Mainz, Johannes Gutenberg-Universitaet, 55099 Mainz (Germany); Novikov, Yu.N. [Petersburg Nuclear Physics Institute, Gatchina, 188300 St. Petersburg (Russian Federation); St. Petersburg State University, 198504 St. Petersburg (Russian Federation); Schweikhard, L. [Institut fuer Physik, Ernst-Moritz-Arndt-Universitaet, 17487 Greifswald (Germany); Shabaev, V.M.; Tupitsyn, I.I. [St. Petersburg State University, 198504 St. Petersburg (Russian Federation); Wycech, S. [Soltan Institute for Nuclear Studies, PL-00-681 Warsaw (Poland); Zuber, K. [Institut fuer Kern- und Teilchenphysik, Technische Universitaet, 01069 Dresden (Germany); Zubova, N.A. [St. Petersburg State University, 198504 St. Petersburg (Russian Federation)

    2012-02-01

    The mass difference of the nuclides {sup 180}W and {sup 180}Hf has been measured with the Penning-trap mass spectrometer SHIPTRAP to investigate {sup 180}W as a possible candidate for the search for neutrinoless double-electron capture. The Q{sub {epsilon}{epsilon}}-value was measured to 143.20(27) keV. This value in combination with the calculations of the atomic electron wave functions and other parameters results in a half-life of the 0{sup +}{yields}0{sup +} ground-state to ground-state double-electron capture transition of approximately 5 Multiplication-Sign 10{sup 27} years/ Left-Pointing-Angle-Bracket m{sub {epsilon}{epsilon}}[eV] Right-Pointing-Angle-Bracket {sup 2}.

  15. Particle track analysis of natural decay series nuclides in sediments and pore waters

    Solid-state nuclear track detectors sensitive to alpha or fission product particles have been used, with some success, to measure low activities of natural decay series nuclides in environmental samples. Applications assessed thus far include excess 230Th and 210Pb dating of sediments, determination of uranium in sediment matrices and pore waters and dissolved 222Rn assay of aqueous solutions. Whenever possible, data obtained by the particle track methods have been compared with the results of conventional radiochemical analyses on duplicate samples. The observed agreement, although illustrating some limitations of particle track techniques, suggests that they have considerable potential in environmental radiochemistry. Not only are the techniques less skilled, less expensive and more portable than coventional methodology, but also they are generally non-destructive, require much less sample, register very low background levels and are, in some cases, more sensitive. (author)

  16. Fuel cycle and waste management. 3. Analysis of PWR Equilibrium Fuel Cycles Using Nuclide Importance

    Energy generation by nuclear reactors entails production of plutonium and radioactive waste. To utilize the plutonium and to minimize the long-term radio-toxic waste, an option is a closed fuel cycle strategy employing reprocessing and recycling of actinides. Since commercial operation of fast reactors is not considered to be realized in the near future, plutonium and minor actinide recycling in light water reactors (LWRs) is considered, although LWR neutron economy is not good. In this study, uranium enrichment, natural uranium requirements, and toxicity of discharged heavy metals (HMs) are evaluated for a pressurized water reactor (PWR), whose design parameters are given in Table I. The following fuel cycles are investigated, where all fission products (FPs) and final products of HMs (Tl-Fr) are discharged from the reactor at a standard rate (25%/yr): Case 1: All HMs are discharged with the standard rate. Case 2: All HMs except Pu are discharged with the standard rate; Pu is discharged at the rate of one-half of the standard rate. Case 3: All HMs except Pu are discharged with the standard rate; Pu is confined. Case 4: All HMs except U are confined; U is discharged with the standard rate. Case 5: All HMs are confined. The infinite multiplication factor k can be expressed by using the nuclide importance (fission neutron importance fj and absorbed neutron importance aj ) as k = (Σj fj sj)/(αΣj aj sj), where sj = atomic percent of uranium isotopes (234U, 235U, and 238U ) in the supplied fuel α = correction factor for estimating neutron absorption by non-fuel-originating nuclides, such as coolant and construction materials. A detailed description of nuclide importance and calculation method is given in Ref. 1. The value k is set to be 1.02, and sj are evaluated from this equation and the following ones: s24 + s25 + s28 = 100 and 100s24 - 0.9937s25=-0.1925. The second equation is given by enrichment conditions. The group cross-section set is generated with the SRAC

  17. Application of electron accelerator worldwide

    Electron accelerator is an important radiation source for radiation technology, which covers broad fields such as industry, health care, food and environmental protection. There are about 1,000 electron accelerators for radiation processing worldwide. Electron accelerator has advantage over Co-60 irradiator in term of high dose rate and power, assurance of safety, and higher economic performance at larger volume of irradiation. Accelerator generating higher energy in the range of 10 MeV and high power electron beam is now commercially available. There is a trend to use high-energy electron accelerator replacing Co-60 in case of large through-put of medical products. Irradiated foods, in particular species, are on the commercial market in 35 countries. Electron accelerator is used efficiently and economically for production of new or modified polymeric materials through radiation-induced cross-linking, grafting and polymerization reaction. Another important application of electron beam is the curing of surface coatings in the manufacture of products. Electron accelerators of large capacity are used for cleaning exhaust gases in industrial scale. Economic feasibility studies of this electron beam process have shown that this technology is more cost effective than the conventional process. It should be noted that the conventional limestone process produce gypsum as a by-product, which cannot be used in some countries. By contrast, the by-product of the electron beam process is a valuable fertilizer. (Y. Tanaka)

  18. The state of the art on nuclides separation in high level liquid wastes by Truex process

    For the advancement of the back-end of nuclear fuel cycle, novel CMPO RUEX process was studied for separating minor actinides from fission products in high level liquid waste using real radioactive solutions from PUREX experiments, so as to support PNC's actinides recycling program using fast reactor. The present PUREX process was also studied to improve the separation of 237Np, 106Ru and 99Tc, the most interfering-natured nuclides in both PUREX and TRUEX processes, by utilizing electrochemistry-based salt-free methods which can eliminate the secondary radioactive waste. The state of the art of separation technologies are described by summarizing the extraction behaviors of nuclides in recent hot counter-current runs using CMPO RUEX process with mild salt-free stripping reagents. The degradation and regeneration characteristics of CMPO/TBP/n-dodecane mixture solvent were also simulated by semi-hot experiments. Several experiments to separate minor actinides and lanthanides from the TRUEX mixture product using aqueous amino-poly-carboxylate complexant, DTPA, resulted in reasonable MA/Ln separation profiles in multiple mixer-settler stages and allowed a unique separation flowsheet adaptable to the TRUEX process to be proposed. Application of electrochemistry to assist both solvent extraction processes, e.g., 'anodic oxidation' to destroy PUREX and TRUEX solvent waste in the presence of electron transfer mediator Age2+ or 'cathodic reduction' for electrolytic extraction of Pd2+, RuNO3+ and 99TcO4- from 3 M nitric acid medium is under study. (authors)

  19. Impact of nuclear data uncertainties on calculated spent fuel nuclide inventories

    The U.S. Department of Energy’s Next Generation Safeguards Initiative Spent Fuel (NGSI‑SF) project is nearing the final phase of developing several advanced nondestructive assay (NDA) instruments designed to measure spent nuclear fuel assemblies for the purpose of improving nuclear safeguards. Current efforts are focusing on calibrating several of these instruments with spent fuel assemblies at two international spent fuel facilities. Modelling and simulation is expected to play an important role in predicting nuclide compositions, neutron and gamma source terms, and instrument responses in order to inform the instrument calibration procedures. As part of NGSI‑SF project, this work was carried out to assess the impacts of uncertainties in the nuclear data used in the calculations of spent fuel content, radiation emissions and instrument responses. Nuclear data is an essential part of nuclear fuel burnup and decay codes and nuclear transport codes. Such codes are routinely used for analysis of spent fuel and NDA safeguards instruments. Hence, the uncertainties existing in the nuclear data used in these codes affect the accuracies of such analysis. In addition, nuclear data uncertainties represent the limiting (smallest) uncertainties that can be expected from nuclear code predictions, and therefore define the highest attainable accuracy of the NDA instrument. This work studies the impacts of nuclear data uncertainties on calculated spent fuel nuclide inventories and the associated NDA instrument response. Recently developed methods within the SCALE code system are applied in this study. The Californium Interrogation with Prompt Neutron instrument was selected to illustrate the impact of these uncertainties on NDA instrument response.

  20. Electrodynamics acceleration of electrical dipoles

    Dolya, S N

    2013-01-01

    This article considers the acceleration of electric dipoles consisting of thin metal plates and dielectric (barium titanate). The dipoles are of a cylindrical shape with a diameter of the cylinder two centimeters and length one centimeter. Capacity of the parallel-plate capacitor is three hundred picofarads and it is charged up to the voltage of two hundred eighty kilovolts. Pre-acceleration of the electric dipoles till velocity one kilometer per second is reached by the gas-dynamic method. The finite acceleration is produced in a spiral waveguide, where the pulse is travelling with voltage amplitude seven hundreds kilovolts and power one hundred twenty-five megawatts. This pulse travels via the spiral waveguide and accelerates the injected electric dipoles in the longitudinal direction till the finite velocity eight and a half kilometers per second over length seven hundred and seventy meters.

  1. Accelerated GLAS exposure station

    The Geoscience Laser Altimeter System (GLAS) is being developed by NASA/GSFC to measure the dynamics of the ice sheet mass balance, land, and cloud and atmospheric properties. An instrument altimetric resolution of 10 cm per shot is required. The laser transmitter will be a diode pumped, Q-switched, Nd:YAG laser producing 1064 nm, 100 mJ, 4 ns pulses at 40 Hz repetition rate in a TEM∞ mode. A minimum lifetime goal of 2 billion shots is required per laser transmitter. The performance of the GLAS laser can be limited by physical damage to the optical components caused by the interaction of intense laser energy with the optical coatings and substrates. Very little data exists describing the effects of long duration laser exposure, of 4 ns pulses, on an optical component. An Accelerated GLAS Exposure Station (AGES) is being developed which will autonomously operate and monitor the GLAS laser at an accelerated rate of 500 Hz. The effects of a large number of laser shots will be recorded. Parameters to be monitored include: laser power, pulsewidth, beam size, laser diode drive current and power, Q-switch drive voltage, temperature, and humidity. For comparison, one set of AGES-sister optical components will be used in the non-accelerated GLAS laser and another will be evaluated by a commercial optical damage test facility

  2. The influence from low energy x-rays and Auger electrons on 4πβ-γ coincidence measurements of electron-capture-decaying nuclides

    The influence of low energy x-rays and Auger electrons emitted by electron capture nuclides on 4πβ-γ coincidence measurements is investigated. Under the assumption that these radiations are not detected, correction terms are developed for a number of nuclides that are in common use. (author)

  3. Influence from low energy x-rays and Auger electrons on 4. pi beta. -. gamma. coincidence measurements of electron-capture-decaying nuclides

    Funck, E.; Larsen, A.N. (Physikalisch-Technische Bundesanstalt, Braunschweig (Germany, F.R.). Abt. Atomphysik; Commission of the European Communities, Geel (Belgium). Central Bureau for Nuclear Measurements)

    1983-03-01

    The influence of low energy x-rays and Auger electrons emitted by electron capture nuclides on 4..pi beta..-..gamma.. coincidence measurements is investigated. Under the assumption that these radiations are not detected, correction terms are developed for a number of nuclides that are in common use.

  4. Calculation of the mass and activity of mixtures of natural radioactive nuclides as a function of time

    To calculate the development of the activity of mixtures of natural nuclides with time, we used a spreadsheet in the PC program EXCEL. The calculations are based on a solution of the set of differential equations with a recursive matrix of coefficients. (orig.)

  5. Studies on the chemical behaviour of radioactive nuclides in fresh water and their accumulation by fresh water organisms

    It is of importance to do the basic investigation on the cycling of radioactive nuclides in terrestrial environments. Up to this time, accumulation, excretion and distribution of radioactive nuclides such as 131I, sup(115m)Cd, 85Sr, 203Hg, 131Ba, 22Na and 58Co in fresh water fish have been investigated. This paper concentrates in accumulation and excretion of 131I, and distribution and excretion of 203Hg-labelled methyl mercury chloride in fresh water fish. It was observed that, under co-existence of IO3-, the concentration factor of 131I concerning fresh water fish came near to that of marine fish as if the accumulation of 131I were stimulated by IO3- ions. Clear difference was recognized on the excretion patterns of 131I between fresh water fish and marine fish. In case of fresh water fish, 131I was excreted much more through kidney than through gills. Biological half-life of 131I from whole body of fresh water fish was about 15 days. Transfer of 203Hg labelled methyl mercury chloride to the brain of carp was investigated by means of abdominal administration of the nuclide. Not so much accumulation was obtained in the brain. Biological half-life of the nuclide from the brain was calculated as 198 days. (author)

  6. Activities of the {sup 7}Be and {sup 137}Cs nuclides in mushrooms from Southern and Western Finland

    Loennroth, T.; Bjoerkholm, A.; Haavisto, T.; Slotte, J.M.K. [Aabo Akademi, Turku (Finland). Dept. of Physics; Lill, J.O. [Aabo Akademi, Turku (Finland). Dept. of Physics; Aabo Akademi, Turku (Finland). Turku PET Centre and Accelerator Lab.

    2011-07-01

    We report the results from activity measurements of {sup 7}Be and {sup 137}Cs nuclides in mushrooms in Southern and Western Finland. Fifty-three samples were studied, and they showed large variations especially in the {sup 137}Cs activity both regionally and between mushroom species. (orig.)

  7. Device for monitoring the concentration of radioactive nuclides particularly of α sources in a gas or a liquid

    The gas, or the aerosol formed from a liquid, is sucked through a capillary tube into a measuring chamber, where the nuclide contained in the gas or aerosol remains on a rotating collecting disc and is then turned to in front of a radiation detector. (orig./HP)

  8. Requests from use experience of ORIGEN code. Activity of the working group on evaluation of nuclide generation and depletion

    A questionnaire survey was carried out through the committee members of the working group on evaluation of nuclide generation and depletion about the demand accuracy of the ORIGEN code which is used widely in various fields of design analysis and evaluation. WG committee asked each organization's ORIGEN user, and obtained the replay from various fields. (author)

  9. Linear accelerator for radioisotope production

    A 200- to 500-μA source of 70- to 90-MeV protons would be a valuable asset to the nuclear medicine program. A linear accelerator (linac) can achieve this performance, and it can be extended to even higher energies and currents. Variable energy and current options are available. A 70-MeV linac is described, based on recent innovations in linear accelerator technology; it would be 27.3 m long and cost approx. $6 million. By operating the radio-frequency (rf) power system at a level necessary to produce a 500-μA beam current, the cost of power deposited in the radioisotope-production target is comparable with existing cyclotrons. If the rf-power system is operated at full power, the same accelerator is capable of producing an 1140-μA beam, and the cost per beam watt on the target is less than half that of comparable cyclotrons

  10. Heavy ion medical accelerator options

    This paper briefly explores the accelerator technology available for heavy ion medical accelerators in the mass range of 1 to 40 (protons through argon). Machines that are designed to produce the required intensities of a particular design ion, such as silicon (mass 28), can satisfy the intensity requirements for all lighter ions, and can produce beams with higher mass, such as argon, at somewhat reduced, but still useful intensity levels. They can also provide beams of radioactive ions, such as carbon-11 and neon-19, which are useful in diagnostic imaging and for directly verifiable treatments. These accelerators are all based on proven technology, and can be built at predictable costs. It is the conclusion of several design studies that they can be operated reliably in a hospital-based environment. 8 refs., 22 figs

  11. Accelerator transmutation studies at Los Alamos with LAHET, MCNP, and CINDER'90

    Versions of the CINDER code have been used over three decades for determination of reactor fuel inventories and aggregate neutron absorption and radioactive decay properties. The CINDER'90 code, an evolving version which requires no predetermined nuclide chain structure, is suitable for a wider range of transmutation problems including those treated with older versions. In recent accelerator transmutation studies, the CINDER'90 code has been linked with the LAHET Code System (LCS) and, for high-energy calculations, with SUPERHET. A description of the nature of these linked calculational tools is given; data requirements for the transmutation studies are described; and, examples of linked calculations are described for some interesting accelerator applications

  12. Accelerator target

    Schlyer, David J. (Bellport, NY); Ferrieri, Richard A. (Patchogue, NY); Koehler, Conrad (Miller Place, NY)

    1999-01-01

    A target includes a body having a depression in a front side for holding a sample for irradiation by a particle beam to produce a radioisotope. Cooling fins are disposed on a backside of the body opposite the depression. A foil is joined to the body front side to cover the depression and sample therein. A perforate grid is joined to the body atop the foil for supporting the foil and for transmitting the particle beam therethrough. A coolant is circulated over the fins to cool the body during the particle beam irradiation of the sample in the depression.

  13. Plasma Channel Guided Laser Wakefield Accelerator

    Geddes, C G

    2005-01-01

    High quality electron beams (several 109 electrons above 80 MeV energy with percent energy spread and low divergence) have been produced for the first time in a compact, high gradient, all-optical laser accelerator by extending the interaction distance using a pre-formed plasma density channel to guide the drive laser pulse. Laser-driven accelerators, in which particles are accelerated by the electric field of a plasma wave (wake) driven by the radiation pressure of an intense laser, have over the past decade demonstrated accelerating fields thousands of times greater than those achievable in conventional radio-frequency accelerators. This has spurred interest in them as compact next- generation sources of energetic electrons and radiation. To date, however, acceleration distances have been severely limited by the lack of a controllable method for extending the propagation distance of the focused laser pulse. The ensuing short acceleration distance resulted in low-energy beams with 100 percent electron energy...

  14. Introduction to Particle Acceleration in the Cosmos

    Gallagher, D. L.; Horwitz, J. L.; Perez, J.; Quenby, J.

    2005-01-01

    Accelerated charged particles have been used on Earth since 1930 to explore the very essence of matter, for industrial applications, and for medical treatments. Throughout the universe nature employs a dizzying array of acceleration processes to produce particles spanning twenty orders of magnitude in energy range, while shaping our cosmic environment. Here, we introduce and review the basic physical processes causing particle acceleration, in astrophysical plasmas from geospace to the outer reaches of the cosmos. These processes are chiefly divided into four categories: adiabatic and other forms of non-stochastic acceleration, magnetic energy storage and stochastic acceleration, shock acceleration, and plasma wave and turbulent acceleration. The purpose of this introduction is to set the stage and context for the individual papers comprising this monograph.

  15. Denudation rates derived from spatially-averaged cosmogenic nuclide analysis in Nelson catchments, South Island, New Zealand

    Burdis, A.; Norton, K. P.; Ditchburn, B.; Zondervan, A.

    2013-12-01

    New Zealand's tectonically and climatically dynamic environment generates erosion rates that outstrip global averages by up to ten times in some locations. In order to assess recent changes in erosion rate, and also to predict future erosion dynamics, it is important to quantify long-term, background erosion. Current research on erosion in New Zealand predominantly covers short-term (100 yrs) erosion dynamics and Myr dynamics from thermochronological proxy data. Without medium-term denudation data for New Zealand, it is uncertain which variables (climate, anthropogenic disturbance of the landscape, tectonic uplift, lithological, or geomorphic characteristics) exert the dominant control on denudation in New Zealand. Spatially-averaged cosmogenic nuclide analysis can effectively offer this information by providing averaged rates of denudation on millennial timescales without the biases and limitations of short-term erosion methods. Basin-averaged denudation rates were obtained in the Nelson region, New Zealand, from analysis of concentrations of meteoric 10Be in clay and in-situ produced 10Be in quartz. The measured denudation rates integrate over ~8000 yrs (meteoric) and ~3000 yrs (in-situ). Not only do the 10Be records produce erosion rates that are remarkably consistent with each other, but they are also independent of topographic metrics. Denudation rates range from ~116 - 306 t km-2 yr-1, with the exception of one basin which is eroding at 789 t km-2 yr-1(derived from meteoric 10Be) and 644 t km-2 yr-1(derived from in-situ 10Be). The homogeneity of rates and absence of a significant correlation with geomorphic or lithological characteristics suggest another factor is exerting the dominant control on landscape denudation in the Nelson region. Storm variability is a likely driver of erosion in this setting. The background rates are higher than current short term rates (~50 - 200 t km-2 yr-1) due to the significant erosion caused by high magnitude, low frequency

  16. Propulsion Through Electromagnetic Self-Sustained Acceleration

    Petkov, Vesselin

    1999-01-01

    As is known the repulsion of the volume elements of an uniformly accelerating charge or a charge supported in an uniform gravitational field accounts for the electromagnetic contribution to the charge's inertial and gravitational mass, respectively. This means that the mutual repulsion of the volume elements of the charge produces the resistance to its accelerated motion. Conversely, the effect of electromagnetic attraction of opposite charges enhances the accelerated motion of the charges pr...

  17. Linear Accelerator (LINAC)

    ... News Physician Resources Professions Site Index A-Z Linear Accelerator A linear accelerator (LINAC) customizes high energy x-rays to ... ensured? What is this equipment used for? A linear accelerator (LINAC) is the device most commonly used ...

  18. Accuracy of 9Be-data and its influence on 10Be cosmogenic nuclide data

    A 9Be-solution has been chemically prepared from phenakite (Be2SiO4) mineral grains as commercial 9Be-solutions are too high in long-lived 10Be. The solution is intended to be used as a carrier for radiochemical separation of 10Be to be measured by accelerator mass spectrometry (AMS). Thus, accurate data of the 9Be-concentration of this solution is essential to guarantee for high-accuracy 10Be data in the future. After devastating preliminary results (∼8 % standard deviation), eight laboratories finally produced twelve individual results by four different analytical methods. A certain lab and method bias might be identified by sophisticated statistical evaluation. Some laboratories also (grossly) underestimate their uncertainties. Thus, the simple weighted mean of this round-robin exercise needed to be corrected by introducing additional allowances (Paule-Mandel-approach). The final result has been calculated to (2,246 ± 11) μg 9Be/(g solution) with a reasonably low weighted standard deviation of 0.49 %. The maximum deviation of a single lab value from the weighted mean is 2.4 % when removing one Grubbs outlier (11 % off from the mean) from the data set. As 10Be-data, which is usually calculated from measured 10Be/9Be by AMS and stable 9Be, cannot be more accurate than the determined 9Be-concentration, it seems highly advisable to establish or improve quality assurance by having self-made carrier-solutions analysed at more than a single lab and regularly taking part in round-robin exercises. (author)

  19. Notes on beam dynamics in linear accelerators

    Gluckstern, R.L.

    1980-09-01

    A collection of notes, on various aspects of beam dynamics in linear accelerators, which were produced by the author during five years (1975 to 1980) of consultation for the LASL Accelerator Technology (AT) Division and Medium-Energy Physics (MP) Division is presented.

  20. Fission rates of nuclides in the neutron field formed on the surface of a massive lead target irradiated with protons at energy of 5.0 Gev

    Fission rates of the nuclides Th-232, U-235 (with and without cadmium filter), U-234, U-236, Np-237 and U-238 were measured on the side surface of a massive lead target irradiated at the Syncrophasotron accelerator (JINR, Dubna) with protons at kinetic energy of 5.0 GeV. These measurements were carried out using the technique of solid-state nuclear track detectors. Comparison of the measured values was made with the results obtained by means of Monte-Carlo simulation using the computer code DCM/CEM. - Highlights: • The spallation neutron source based on a massive lead target irradiated with 5.0 GeV protons. • The technique of solid-state nuclear track detectors was used for the measurements. • Fission rates of 232Th, 237Np and uranium isotopes were measured for a spallation neutron source. • The measured values are compared with the results of Monte-Carlo simulation