WorldWideScience

Sample records for accelerator produced nuclides

  1. Determination of nuclide inventories in accelerator radwaste

    Energy Technology Data Exchange (ETDEWEB)

    Weinreich, R.; Argentini, M.; Schumann, D. [Lab. of Radio- and Environmental Chemistry, Paul Scherrer Inst. Villigen-PSI (Switzerland)

    2003-07-01

    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 {gamma}-spectrometry, {alpha}-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 1.10{sup 7} Bq/g for {sup 60}Co and 1.10{sup -5} Bq/g for {sup 60}Fe. (ii) In shielding concrete, more than 30 mBq/g {sup 239,240}Pu were found which is higher than the exemption limit. (iii) In graphite targets, at end of bombardment 2.10{sup 11} Bq/g {sup 7}Be 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.)

  2. 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

    Institute of Scientific and Technical Information of China (English)

    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

  3. Method for net decrease of hazardous radioactive nuclear waste materials. [Thermal neutron irradiation of long-lived radionuclides to produce stable nuclides and short-lived radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Marriott, R.; Henyey, F.S.; Hochstim, A.R.

    1988-01-26

    A method of decreasing the amount of relatively long lived fission products in radioactive waste materials in excess of that due to their natural radioactive decay by producing relatively short lived radioactive nuclides and stable nuclides from the relatively long lived fission products is described comprising the steps of: (a) separating the fission products into at least (1) physically separate groups, and (2) relatively short lived fission product radioactive nuclides and stable nuclides; (b) storing the relatively short lived radioactive nuclides and stable nuclides; (c) exposing at least the groups containing Kr/sup 85/, Sr/sup 90/, Zr/sup 93/, Tc/sup 99/, Pd/sup 107/, I/sup 129/, Cs/sup 135/, Sm/sup 151/ + Eu, and actinides, to a high thermal neutron flux for separate, different predetermined periods of time selected in accordance with the long lived fission product nuclide in the corresponding group for inducing predetermined transformations of the relatively long lived fission product nuclides to produce relatively short lived radioactive nuclides and stable nuclides; (d) removing each exposed group containing the produced relatively short lived radioactive nuclides and stable nuclides from the high thermal neutron flux; (e) separating the removed group into (1) the produced short lived radioactive nuclides and stable nuclides, and (2) a plurality of further groups having long lived fission product nuclides respectively corresponding to at least some of the long lived fission product nuclides or the groups of step (a); (f) storing the produced short lived radioactive nuclides and stable nuclides; (g) joining at least one of the further groups to at least one of the groups of step (a) having a corresponding long lived fission product nuclide.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    ZHOU Feng-Qun; SONG Yue-Li; TUO Fei; KONG Xiang-Zhong

    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 deduced,and it is pointed out that the activation formula given in two references is incorrect.Then,as an example,the so-called total activation cross section in one of the two references is analyzed and the correct results of the cross sections of 182W(n,p)182(m+g)Ta,183W(n,p)183Ta and 206Pb(n,a)203Hg induced by neutrons around 14 MeV calculated with the data given in the literature,the nuclear parameters and some evaluated values are given.Finally,the correct results are compared with other values collected in the literature.

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

    CERN Document Server

    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.

  9. Very Big Accelerators as Energy Producers

    CERN Document Server

    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...

  10. Properties of the accelerator-produced beam

    Energy Technology Data Exchange (ETDEWEB)

    Caporaso, G.J.; Chambers, F.W.; Cole, A.G.; Fawley, W.M.; Struve, K.W.

    1985-10-11

    Obtaining detailed knowledge of the condition of the electron beam delivered to the experimental tank is of prime importance in the attempt to correlate the propagation data with theory. There are many interesting and unique features of the beam delivered by Advanced Test Accelerator (ATA) to the experimental tank.

  11. Cosmogenic nuclides in meteorites

    Energy Technology Data Exchange (ETDEWEB)

    Merchel, Silke; Akhmadaliev, Shavkat; Rugel, Georg [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Cartwright, Julia A.; Ott, Ulrich [MPI fuer Chemie, Mainz (Germany); Faestermann, Thomas; Fimiani, Leticia; Korschinek, Gunther; Ludwig, Peter [TU Muenchen, Garching (Germany)

    2012-07-01

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

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

    CERN Document Server

    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...

  13. Effective determination of the long-lived nuclide 41Ca in nuclear reactor bioshield concretes: comparison of liquid scintillation counting and accelerator mass spectrometry.

    Science.gov (United States)

    Warwick, P E; Croudace, I W; Hillegonds, D J

    2009-03-01

    The routine application of liquid scintillation counting to (41)Ca determination has been hindered by the absence of traceable calibration standards of known (41)Ca activity concentrations. The introduction of the new IRMM (41)Ca mass-spectrometric standards with sufficiently high (41)Ca activities for radiometric detection has partly overcome this although accurate measurement of stable Ca concentrations coupled with precise half-life data are still required to correct the certified (41)Ca:(40)Ca ratios to (41)Ca activity concentrations. In this study, (41)Ca efficiency versus quench curves have been produced using the IRMM standard, and their accuracy validated by comparison with theoretical calculations of (41)Ca efficiencies. Further verification of the technique was achieved through the analysis of (41)Ca in a reactor bioshield core that had been previously investigated for other radionuclide variations. Calcium-41 activity concentrations of up to 25 Bq/g were detected. Accelerator mass spectrometry (AMS) measurements of the same suite of samples showed a very good agreement, providing validation of the procedure. Calcium-41 activity concentrations declined exponentially with distance from the core of the nuclear reactor and correlated well with the predicted neutron flux.

  14. Emission of SN 1006 produced by accelerated cosmic rays

    CERN Document Server

    Berezhko, E G; Völk, H J

    2002-01-01

    The nonlinear kinetic model of cosmic ray (CR) acceleration in supernova remnants (SNRs) is used to describe the properties of the remnant of SN 1006. It is shown, that the theory fits the existing data in a satisfactory way within a set of parameters which is consistent with the idea that SN 1006 is a typical Galactic CR source. The adjusted parameters are those that are not very well determined by present theory or not directly amenable to astronomical observations. The calculated expansion law and the radio-, X-ray and gamma-ray emissions produced by the accelerated CRs in SN 1006 agree quite well with the observations. A quite large interior magnetic field of about 0.1 mG is required to give a good fit for the radio and X-ray synchrotron emission. In the observed TeV gamma-ray flux from SN 1006, the pion-decay gamma-rays, generated by the nuclear CR component, dominate over the inverse Compton (IC) gamma-rays, generated by the CR electrons in the cosmic microwave background. The predicted hard integral ga...

  15. Nuclide Guide and International Chart of Nuclides - 2008

    Science.gov (United States)

    Golashvili, T.

    2009-08-01

    New versions of Nuclide Guide and Chart of the Nuclides were developed as a result of Russian-Chinese collaboration. The Nuclide Guide contains the basic information on more than 3000 radioactive and stable nuclides. The characteristics of isomers with half-lives more than 1 ms are included. For each nuclide spin, parity, mass of nuclide, magnetic moment (if available), mass excess, half-life or abundance, decay modes, branching ratios, emitted particles, energies of most intense gamma-rays and their intensities, decay energies and mean values of radiation energy per decay are given. For stable and natural long-lived nuclides cross-sections of thermal neutron induced activation are indicated. The information presented in the Guide was compiled from 5 sources: 1) ENSDF-2008, 2) atomic mass evaluation-2005 by Audi and Wapstra, 3) interactive data bases at web-sites , , 4) original evaluations of authors, 5) recent publications. The International Chart ot Nuclides was developed on the basis of information presented in Nuclide Guide.

  16. Radioactivity Measurement of Short Life Nuclide 89Rb

    Institute of Scientific and Technical Information of China (English)

    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

  17. Producing Massive Neutral Intermediate Vector Bosons with Existing Accelerators

    CERN Document Server

    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.

  18. Uptake of nuclides by plants

    Energy Technology Data Exchange (ETDEWEB)

    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.

  19. Transmutation of $^{239}$Pu and Other Nuclides Using Spallation Neutrons Produced by Relativistic Protons Reacting with Massive U- and Pb-Targets

    CERN Document Server

    Adam, J; Bamblevski, V P; Barabanov, M Yu; Bradnova, V; Chaloun, P; Hella, K M; Kalinnikov, V G; Krivopustov, M I; Kulakov, B A; Perelygin, V P; Pronskikh, V S; Pavliouk, A V; Solnyshkin, A A; Sosnin, A N; Stegailov, V I; Tsoupko-Sitnikov, V M; Zaverioukha, O S; Adloff, J C; Debeauvais, M; Brandt, R; Langrock, E J; Vater, P; Van, J S; Westmeier, W; Dwivedi, K K; Guo Shi Lun; Li Li Qiang; Hashemi-Nezhad, S R; Kievets, M K; Lomonosova, E M; Zhuk, I V; Modolo, G; Odoj, R; Zamani-Valassiadou, M

    2001-01-01

    Experimental studies on the transmutation of some long-lived radioactive waste nuclei, such as ^{129}I, ^{237}Np, and ^{239}Pu, as well as on natural uranium and lanthanum (all of them used as sensors) were carried out at the Synchrophasotron of the Laboratory for High Energies (JINR, Dubna). Spallation neutrons were produced by relativistic protons with energies in the range of 0.5 GeV\\le E(p)\\le 1.5 GeV interacting with 20 cm long uranium or lead target stacks. The targets were surrounded by 6 cm paraffin moderators. The radioactive sensors mentioned above were positioned on the outside surface of the moderator and contained typically approximately 0.5 up to 1 gram of long-lived isotopes. The highly radioactive targets were produced perfectly well-sealed in aluminum containers by the Institute of Physics and Power Engineering, Obninsk, Russia. From the experimentally observed transmutation rates one can easily extrapolate, that in a subcritical nuclear power assembly (or "energy amplifier") using a 10 mA pr...

  20. Techniques to produce and accelerate radioactive ion beams

    CERN Document Server

    Penescu, Liviu Constantin; Lettry, Jacques; Cata-Danil, Gheorghe

    The production and acceleration of the Radioactive Ion Beams (RIB) continues the long line of nuclear investigations started in the XIXth century by Pierre and Marie Curie, Henri Becquerel and Ernest Rutherford. The contemporary applications of the RIBs span a wide range of physics fields: nuclear and atomic physics, solid-state physics, life sciences and material science. ISOLDE is a world-leading Isotope mass-Separation On-Line (ISOL) facility hosted at CERN in Geneva for more than 40 years, offering the largest variety of radioactive ion beams with, until now, more than 1000 isotopes of more than 72 elements (with Z ranging from 2 to 88), with half-lives down to milliseconds and intensities up to 1011 ions/s. The post acceleration of the full variety of beams allows reaching final energies between 0.8 and 3.0 MeV/u. This thesis describes the development of a new series of FEBIAD (“Forced Electron Beam Induced Arc Discharge”) ion sources at CERN-ISOLDE. The VADIS (“Versatile Arc Discharge Ion Source�...

  1. Application of different nuclides in retrospective dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Konheiser, J.; Mittag, S.; Viehrig, H.W. [Helmholtz-Zentrum Dresden-Rossendorf e.V. HZDR, PF 510119, D-01314 Dresden (Germany); Gleisberg, B. [Verein fuer Kernverfahrenstechnik und Analytik Rossendorf e.V. VKTA, Bautzner Landstrasse 400, D-01328 Dresden (Germany)

    2011-07-01

    The activities of nuclides produced via the neutron irradiation of reactor pressure vessel (RPV) steel are used to validate respective fluence calculations. Niobium, nickel, and technetium isotopes from RPV trepans of the decommissioned NPP Greifswald (VVER-440) have been analyzed. The activities were determined by TRAMO (Monte-Carlo) fluence calculations, newly applying 640 neutron-energy groups and ENDF/B7 data. Relative to earlier results, fluences up to 20% higher have been computed, leading to somewhat better agreement between measurement and calculation, particularly in the case of Tc-99. (authors)

  2. Modification of semiconductor materials using laser-produced ion streams additionally accelerated in the electric fields

    Science.gov (United States)

    Rosinski, M.; Badziak, B.; Parys, P.; Wołowski, J.; Pisarek, M.

    2009-03-01

    The laser-produced ion stream may be attractive for direct ultra-low-energy ion implantation in thin layer of semiconductor for modification of electrical and optical properties of semiconductor devices. Application of electrostatic fields for acceleration and formation of laser-generated ion stream enables to control the ion stream parameters in broad energy and current density ranges. It also permits to remove the useless laser-produced ions from the ion stream designed for implantation. For acceleration of ions produced with the use of a low fluence repetitive laser system (Nd:glass: 2 Hz, pulse duration: 3.5 ns, pulse energy:˜0.5 J, power density: 10 10 W/cm 2) in IPPLM the special electrostatic system has been prepared. The laser-produced ions passing through the diaphragm (a ring-shaped slit in the HV box) have been accelerated in the system of electrodes. The accelerating voltage up to 40 kV, the distance of the diaphragm from the target, the diaphragm diameter and the gap width were changed for choosing the desired parameters (namely the energy band of the implanted ions) of the ion stream. The characteristics of laser-produced Ge ion streams were determined with the use of precise ion diagnostic methods, namely: electrostatic ion energy analyser and various ion collectors. The laser-produced and post-accelerated Ge ions have been used for implantation into semiconductor materials for nanocrystal fabrication. The characteristics of implanted samples were measured using AES.

  3. Modification of semiconductor materials using laser-produced ion streams additionally accelerated in the electric fields

    Energy Technology Data Exchange (ETDEWEB)

    Rosinski, M. [Institute of Plasma Physics and Laser Microfusion, P.O. Box 49, Hery Street 23, 00-908 Warsaw (Poland)], E-mail: rosinski@ifpilm.waw.pl; Badziak, B.; Parys, P.; Wolowski, J. [Institute of Plasma Physics and Laser Microfusion, P.O. Box 49, Hery Street 23, 00-908 Warsaw (Poland); Pisarek, M. [Warsaw University of Technology, Material Science and Engineering Faculty, Warsaw (Poland)

    2009-03-01

    The laser-produced ion stream may be attractive for direct ultra-low-energy ion implantation in thin layer of semiconductor for modification of electrical and optical properties of semiconductor devices. Application of electrostatic fields for acceleration and formation of laser-generated ion stream enables to control the ion stream parameters in broad energy and current density ranges. It also permits to remove the useless laser-produced ions from the ion stream designed for implantation. For acceleration of ions produced with the use of a low fluence repetitive laser system (Nd:glass: 2 Hz, pulse duration: 3.5 ns, pulse energy:{approx}0.5 J, power density: 10{sup 10} W/cm{sup 2}) in IPPLM the special electrostatic system has been prepared. The laser-produced ions passing through the diaphragm (a ring-shaped slit in the HV box) have been accelerated in the system of electrodes. The accelerating voltage up to 40 kV, the distance of the diaphragm from the target, the diaphragm diameter and the gap width were changed for choosing the desired parameters (namely the energy band of the implanted ions) of the ion stream. The characteristics of laser-produced Ge ion streams were determined with the use of precise ion diagnostic methods, namely: electrostatic ion energy analyser and various ion collectors. The laser-produced and post-accelerated Ge ions have been used for implantation into semiconductor materials for nanocrystal fabrication. The characteristics of implanted samples were measured using AES.

  4. A new approach to characterize very-low-level radioactive waste produced at hadron accelerators.

    Science.gov (United States)

    Zaffora, Biagio; Magistris, Matteo; Chevalier, Jean-Pierre; Luccioni, Catherine; Saporta, Gilbert; Ulrici, Luisa

    2017-04-01

    Radioactive waste is produced as a consequence of preventive and corrective maintenance during the operation of high-energy particle accelerators or associated dismantling campaigns. Their radiological characterization must be performed to ensure an appropriate disposal in the disposal facilities. The radiological characterization of waste includes the establishment of the list of produced radionuclides, called "radionuclide inventory", and the estimation of their activity. The present paper describes the process adopted at CERN to characterize very-low-level radioactive waste with a focus on activated metals. The characterization method consists of measuring and estimating the activity of produced radionuclides either by experimental methods or statistical and numerical approaches. We adapted the so-called Scaling Factor (SF) and Correlation Factor (CF) techniques to the needs of hadron accelerators, and applied them to very-low-level metallic waste produced at CERN. For each type of metal we calculated the radionuclide inventory and identified the radionuclides that most contribute to hazard factors. The methodology proposed is of general validity, can be extended to other activated materials and can be used for the characterization of waste produced in particle accelerators and research centres, where the activation mechanisms are comparable to the ones occurring at CERN. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Electron acceleration in collisionless shocks and magnetic reconnection by laser-produced plasma ablation

    Science.gov (United States)

    Park, Jaehong; Spitkovksy, Anatoly; Fox, Will; Bhattacharjee, Amitava

    2016-10-01

    We perform particle-in-cell simulations of collisionless shocks and magnetic reconnection generated by ablated plasma expanding into a magnetized background plasma. We find: (1) The simulated proton radiography produces different morphology of the shock structure depending on the orientation of the magnetic field and can be used to identify a shock in the experiment. Electrons are accelerated by the whistler waves generated at oblique sites of the shock. (2) Forced collisionless magnetic reconnection is induced when the expanding plumes carry opposite magnetic polarities and interact with a background plasma. Electrons are accelerated at the reconnection X line and reveal a power-law distribution as the plasma beta is lowered, β = 0.08 . As the plasma beta is increased, β = 0.32 , the 1st order Fermi mechanism against the two plasma plumes contributes to the electron acceleration as well as the X line acceleration. Using 3-D simulations, we also explore the effect of 3-D instabilities (Weibel instability or drift-kink) on particle acceleration and magnetic field annihilation between the colliding magnetized plumes

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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.

  8. Electrostatic acceleration and deflection system for modification of semiconductor materials in laser-produced ion implantation

    Science.gov (United States)

    Rosinski, M.; Parys, P.; Wolowski, J.; Gasior, P.; Pisarek, M.

    2010-10-01

    To optimize the efficiency of laser ion implantation technology, it is advisable to properly select the laser beam characteristics (i.e. power density, target illumination geometry, etc.). In many applications, it is important to select a specific range of ion energy to implant the ions at a given depth and at a given density. To make it possible, the electrostatic system for acceleration and deflection of low-energy laser-produced ions can be used. This contribution provides a description of the experiments aimed at the implantation of Ge ions from a narrow energy band onto SiO2/Si substrates, which were conducted at IPPLM. As the source of irradiation, we used a Nd:YAG up to 10 Hz laser system with pulse duration of 3.5 ns and pulse energy ∼ 0.5 J, which gave a power density of 1010 W/cm2. The ion stream parameters were measured using the time-of-fight method. The laser-produced ions passing through the diaphragm have been accelerated in the system of electrodes. Due to the electrostatic field configuration provided by the electrode system and a diaphragm located at the axis of the system, the selected ions were focussed at the area of interest to increase implantation density. The accelerating voltage, the distance of the diaphragm from the target, the diaphragm diameter and the gap width between electrodes were changed for choosing the desired parameters of the ion stream.

  9. Probing particle acceleration in lower hybrid turbulence via synthetic diagnostics produced by PIC simulations

    Science.gov (United States)

    Cruz, F.; Fonseca, R. A.; Silva, L. O.; Rigby, A.; Gregori, G.; Bamford, R. A.; Bingham, R.; Koenig, M.

    2016-10-01

    Efficient particle acceleration in astrophysical shocks can only be achieved in the presence of initial high energy particles. A candidate mechanism to provide an initial seed of energetic particles is lower hybrid turbulence (LHT). This type of turbulence is commonly excited in regions where space and astrophysical plasmas interact with large obstacles. Due to the nature of LH waves, energy can be resonantly transferred from ions (travelling perpendicular to the magnetic field) to electrons (travelling parallel to it) and the consequent motion of the latter in turbulent shock electromagnetic fields is believed to be responsible for the observed x-ray fluxes from non-thermal electrons produced in astrophysical shocks. Here we present PIC simulations of plasma flows colliding with magnetized obstacles showing the formation of a bow shock and the consequent development of LHT. The plasma and obstacle parameters are chosen in order to reproduce the results obtained in a recent experiment conducted at the LULI laser facility at Ecole Polytechnique (France) to study accelerated electrons via LHT. The wave and particle spectra are studied and used to produce synthetic diagnostics that show good qualitative agreement with experimental results. Work supported by the European Research Council (Accelerates ERC-2010-AdG 267841).

  10. A MiniBooNE Accelerator-Produced (sub)-GeV Dark Matter Search

    Science.gov (United States)

    Thornton, Remington; MiniBooNE-DM Collaboration

    2016-09-01

    Cosmological observations indicate that our universe contains dark matter (DM), yet we have no measurements of its microscopic properties. Whereas the gravitational interaction of DM is well understood, its interaction with the Standard Model is not. Direct detection experiments search for a nuclear recoil interaction produced by a DM relic particle and have a low-mass sensitivity edge of order 1 GeV. To detect DM with mass below 1 GeV, either the sensitivity of the experiments needs to be improved or use of accelerators producing boosted low-mass DM are needed. Using neutrino detectors to search for low-mass DM is logical due to the similarity of the DM and ν signatures in the detector. The MiniBooNE experiment, located at Fermilab on the Booster Neutrino Beamline, ran for 10 years in ν and ν modes and is already well understood, making it desirable to search for accelerator-produced boosted low-mass DM. A search for DM produced by 8 GeV protons hitting a steel beam-dump has finished, collecting 1 . 86 ×1020 POT . Final analysis containing 90% confidence limits and a model independent fit will be presented.

  11. Simulations of terrestrial in-situ cosmogenic-nuclide production

    Energy Technology Data Exchange (ETDEWEB)

    Reedy, R.C. [Los Alamos National Lab., NM (United States); Nishiizumi, K.; Arnold, J.R. [California Univ., San Diego, La Jolla, CA (United States). Dept. of Chemistry; Lal, D. [Scripps Institution of Oceanography, La Jolla, CA (United States); Englert, P.A.J. [San Jose State Univ., CA (United States). Nuclear Science Facility; Klein, J.; Middleton, R. [Pennsylvania Univ., Philadelphia, PA (United States). Dept. of Physics; Jull, A.J.T.; Donahue, D.J. [Univ. of Arizona, Tucson, AZ (United States). NSF Accelerator Facility for Radioisotope Analysis

    1993-12-31

    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 {sup 7}Be and {sup 22}Na, and accelerator mass spectrometry was used to measure {sup 10}Be, {sup 14}C, and {sup 26}Al. 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.

  12. Lithium neutron producing target for BINP accelerator-based neutron source.

    Science.gov (United States)

    Bayanov, B; Belov, V; Kindyuk, V; Oparin, E; Taskaev, S

    2004-11-01

    Pilot innovative accelerator-based neutron source for neutron capture therapy is under construction now at the Budker Institute of Nuclear Physics, Novosibirsk, Russia. One of the main elements of the facility is lithium target, that produces neutrons via threshold (7)Li(p,n)(7)Be reaction at 25 kW proton beam with energies 1.915 or 2.5 MeV. In the present report, the results of experiments on neutron producing target prototype are presented, the results of calculations of hydraulic resistance for heat carrier flow and lithium layer temperature are shown. Calculation showed that the lithium target could run up to 10 mA proton beam before melting. Choice of target variant is substantiated. Program of immediate necessary experiments is described. Target design for neutron source constructed at BINP is presented. Manufacturing the neutron producing target up to the end of 2004 and obtaining a neutron beam on BINP accelerator-based neutron source are planned during 2005.

  13. Lithium neutron producing target for BINP accelerator-based neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Bayanov, B.; Belov, V.; Kindyuk, V.; Oparin, E.; Taskaev, S. E-mail: taskaev@inp.nsk.su

    2004-11-01

    Pilot innovative accelerator-based neutron source for neutron capture therapy is under construction now at the Budker Institute of Nuclear Physics, Novosibirsk, Russia. One of the main elements of the facility is lithium target, that produces neutrons via threshold {sup 7}Li(p,n){sup 7}Be reaction at 25 kW proton beam with energies 1.915 or 2.5 MeV. In the present report, the results of experiments on neutron producing target prototype are presented, the results of calculations of hydraulic resistance for heat carrier flow and lithium layer temperature are shown. Calculation showed that the lithium target could run up to 10 mA proton beam before melting. Choice of target variant is substantiated. Program of immediate necessary experiments is described. Target design for neutron source constructed at BINP is presented. Manufacturing the neutron producing target up to the end of 2004 and obtaining a neutron beam on BINP accelerator-based neutron source are planned during 2005.

  14. Existence of the fifth unstable nuclide series

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Reedy, R.C., E-mail: reedy@psi.edu

    2015-10-15

    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.

  16. Coupled-Multiplier Accelerator Produces High-Power Electron Beams for Industrial Applications

    Science.gov (United States)

    Hatridge, M.; McIntyre, P.; Roberson, S.; Sattarov, A.; Thomas, E.; Meitzler, Charles

    2003-08-01

    The coupled multiplier is a new approach to efficient generation of MeV d.c. power for accelerator applications. High voltage is produced by a series of modules, each of which consists of a high-power alternator, step-up transformer, and 3-phase multiplier circuit. The alternators are connected mechanically along a rotating shaft, and connected by insulating flexible couplers. This approach differs from all previous d.c. technologies in that power is delivered to the various stages of the system mechanically, rather than through capacitive or inductive electrical coupling. For this reason the capital cost depends linearly on required voltage and power, rather than quadratically as with conventional technologies. The CM technology enables multiple electron beams to be driven within a common supply and insulating housing. MeV electron beam is extremely effective in decomposing organic contaminants in water. A 1 MeV, 100 kW industrial accelerator using the CM technology has been built and is being installed for treatment of wastewater at a petrochemical plant.

  17. Gamma-ray emission from Cassiopeia A produced by accelerated cosmic rays

    CERN Document Server

    Berezhko, E G; Völk, H J

    2003-01-01

    The nonlinear kinetic model of cosmic ray (CR) acceleration in supernova remnants (SNRs) is used to describe the relevant properties of Cassiopeia A (Cas A). In order to reproduce the SNR's observed size, expansion rate and thermal X-ray emission we employ a piecewise homogeneous model for the progenitor's circumstellar medium developed by Borkowski et al. (1996). It consists of a tenuous inner wind bubble, a dense shell of swept-up red supergiant wind material, and a subsequent red supergiant wind region. A quite large SNR interior magnetic field B_d approx 1 mG is required to give a good fit for the radio and X-ray synchrotron emission. The steep radio spectrum is consistent with efficient proton acceleration which produces a significant shock modification and leads to a steep electron spectrum at energies E_e < 1 GeV. The calculated integral gamma-ray flux from Cas A, F propto E_gamma^-1, is dominated by pi^0-decay gamma-rays due to relativistic protons. It extends up to roughly 30 TeV if CR diffusion i...

  18. High-intensity laser-accelerated ion beam produced from cryogenic micro-jet target

    Energy Technology Data Exchange (ETDEWEB)

    Gauthier, M., E-mail: maxence.gauthier@stanford.edu; Kim, J. B.; Curry, C. B.; Gamboa, E. J.; Göde, S.; Propp, A.; Glenzer, S. H. [SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Aurand, B.; Willi, O. [Heinrich-Heine-University Düsseldorf, Düsseldorf (Germany); Goyon, C.; Hazi, A.; Pak, A.; Ruby, J.; Williams, G. J. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Kerr, S. [University of Alberta, Edmonton, Alberta T6G 1R1 (Canada); Ramakrishna, B. [Indian Institute of Technology, Hyderabad (India); Rödel, C. [SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Friedrich-Schiller-University Jena, Jena (Germany)

    2016-11-15

    We report on the successful operation of a newly developed cryogenic jet target at high intensity laser-irradiation. Using the frequency-doubled Titan short pulse laser system at Jupiter Laser Facility, Lawrence Livermore National Laboratory, we demonstrate the generation of a pure proton beam a with maximum energy of 2 MeV. Furthermore, we record a quasi-monoenergetic peak at 1.1 MeV in the proton spectrum emitted in the laser forward direction suggesting an alternative acceleration mechanism. Using a solid-density mixed hydrogen-deuterium target, we are also able to produce pure proton-deuteron ion beams. With its high purity, limited size, near-critical density, and high-repetition rate capability, this target is promising for future applications.

  19. High-intensity laser-accelerated ion beam produced from cryogenic micro-jet target

    Science.gov (United States)

    Gauthier, M.; Kim, J. B.; Curry, C. B.; Aurand, B.; Gamboa, E. J.; Göde, S.; Goyon, C.; Hazi, A.; Kerr, S.; Pak, A.; Propp, A.; Ramakrishna, B.; Ruby, J.; Willi, O.; Williams, G. J.; Rödel, C.; Glenzer, S. H.

    2016-11-01

    We report on the successful operation of a newly developed cryogenic jet target at high intensity laser-irradiation. Using the frequency-doubled Titan short pulse laser system at Jupiter Laser Facility, Lawrence Livermore National Laboratory, we demonstrate the generation of a pure proton beam a with maximum energy of 2 MeV. Furthermore, we record a quasi-monoenergetic peak at 1.1 MeV in the proton spectrum emitted in the laser forward direction suggesting an alternative acceleration mechanism. Using a solid-density mixed hydrogen-deuterium target, we are also able to produce pure proton-deuteron ion beams. With its high purity, limited size, near-critical density, and high-repetition rate capability, this target is promising for future applications.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  1. PRODUCTION CONSIDERATIONS FOR THE CLASSICAL PET NUCLIDES.

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. Accelerator Mass Spectrometry in Laboratory Nuclear Astrophysics

    Science.gov (United States)

    Nusair, O.; Bauder, W.; Gyürky, G.; Paul, M.; Collon, P.; Fülöp, Zs; Greene, J.; Kinoshita, N.; Palchan, T.; Pardo, R.; Rehm, K. E.; Scott, R.; Vondrasek, R.

    2016-01-01

    The extreme sensitivity and discrimination power of accelerator mass spectrometry (AMS) allows for the search and the detection of rare nuclides either in natural samples or produced in the laboratory. At Argonne National Laboratory, we are developing an AMS setup aimed in particular at the detection of medium and heavy nuclides, relying on the high ion energy achievable with the ATLAS superconducting linear accelerator and on gas-filled magnet isobaric separation. The setup was recently used for the detection of the 146Sm p-process nuclide and for a new determination of the 146Sm half-life (68.7 My). AMS plays an important role in the measurement of stellar nuclear reaction cross sections by the activation method, extending thus the technique to the study of production of long-lived radionuclides. Preliminary measurements of the 147Sm(γ,n)146Sm are described. A measurement of the 142Nd(α,γ)146Sm and 142Nd(α,n)145Sm reactions is in preparation. A new laser-ablation method for the feeding of the Electron Cyclotron Resonance (ECR) ion source is described.

  3. Research on Nuclear Reaction Network Equation for Fission Product Nuclides

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Nuclear Reaction Network Equation calculation system for fission product nuclides was developed. With the system, the number of the fission product nuclides at different time can be calculated in the different neutron field intensity and neutron energy spectra

  4. ISOLTRAP pins down masses of exotic nuclides

    CERN Document Server

    Blaum, Klaus; Beck, D; Bollen, G; Brodeur, M; Delahaye, P; George, S; Guenaut, C; Herfurth, F; Herlert, Alexander; Kellerbauer, A G; Kluge, H J; Lunney, M D; Mukherjee, M; Rodríguez, D; Schwarz, S; Schweikhard, L; Yazidjian, C

    2005-01-01

    The mass of radionuclides contribute to a variety of fundamental studies including tests of the weak interaction and the standard model. The limits of mass measurements on exotic nuclides have been extended considerably by the Penning-trap mass spectrometer ISOLTRAP at the ISOLDE facility at CERN. Recent ISOLTRAP measurements are summarized and current technical improvements are outlined.

  5. Production profiles of nuclides by galactic-cosmic-ray particles in small meteoroids

    Science.gov (United States)

    Reedy, R. C.; Masarik, J.

    Many of the meteorites found in cold and hot deserts are small, and many were small bodies in space. Production of cosmic-ray-produced (cosmogenic) nuclides in small meteoroids is expected to be different than that in the larger meteoroids typically studied, with lower levels of nuclide production by galactic-cosmic-ray (GCR) particles and possibly significant production by solar-cosmic-ray (SCR) protons. Motivated by the cosmogenic-nuclide measurements for the very small Salem meteorite and for cosmic spherules, which show high levels of SCR production, we have reported earlier nuclide production rates by SCR protons in small objects in space. The GCR production rates reported for small meteoroids have not been tested and were expected to be poor for meteoroids with radii less than 40 g/cm2 because of the very simple nature of that semi-empirical model (only one free parameter) and because the mix of neutrons and protons is different (relatively more protons) than that in the model, which was based on larger objects. Thus we have calculated produciton rates for nuclides mad by GCR particles in small objects with a physical model that is much better suited for unusual targets.

  6. Peak ground acceleration produced by local earthquakes in volcanic areas of Campi Flegrei and Mt. Vesuvius

    Directory of Open Access Journals (Sweden)

    S. Petrosino

    2004-06-01

    Full Text Available The scaling law of the seismic spectrum experimentally calculated at Mt. Vesuvius and Campi Flegrei is used to constrain the estimate of the maximum expected peak acceleration of ground motion.

  7. Calculation of Generation Rate of Electron Ion Pairs Ionized by Radioactive Nuclide in Air

    Institute of Scientific and Technical Information of China (English)

    WU; Xiu-feng; ZHANG; Li-feng; LUO; Zhi-fu

    2015-01-01

    Alpha and beta nuclides are widely employed in industrial production and life for the ability of ionization.Static eliminator,ionization smoke detector,electron capture detector and radioactive lightning rod are some typical examples.Alpha/beta rays produce electrons by ionizing the air,and then the charge is transferred during

  8. Study of particle transport in a high power spallation target for an accelerator driven transmutation system

    OpenAIRE

    Shetty, Nikhil Vittal

    2013-01-01

    Transmutation of highly radioactive nuclear waste can be performed using an accelerator driven system (ADS), where high energy protons impinge on a spallation target to produce neutrons. These neutrons are multiplied in a subcritical core, while simultaneously fissioning the minor actinides into short lived or stable nuclides. AGATE is a project envisaged to demonstrate the feasibility of transmutation in a gas (helium) cooled ADS using solid spallation target. Development of the spallation t...

  9. Global sediment production from in-situ cosmogenic nuclides in large river basins

    Science.gov (United States)

    Haedke, H.; Wittmann, H.; von Blanckenburg, F.; Gaillardet, J.

    2016-12-01

    The worlds 30 largest rivers represent half of the total runoff to the ocean and thus integrate the fluxes of Earth surface weathering and erosion over a large portion of global tectonic, geomorphic, and climatic zones. In-situ produced cosmogenic nuclides (10Be, 26Al) in detrital quartz sand can be used to constrain the mean millennial-scale denudation of these large basins. Yet cosmogenic nuclides have mostly been applied to small and intermediate size basins of significant relief. One reason is that in these settings, lowland sediment storage and burial are short compared to the half life of the nuclide (e.g. 1.4 Myr for 10Be). However, if sediment storage is long compared to the half-life, paired nuclides (e.g. 26Al/10Be), through their differential decay, allow to assess the duration of sediment transfer and burial ages from source to sink[1]. Here we present a new dataset of cosmogenic nuclides from 60 large rivers that integrate over 30% of Earth's terrestrial surface. 26Al/10Be ratios of around 6 to 7.5 for most rivers reveal burial durations shorter than the nuclides' decay time scales, indicating high source-sink connectivity. In slowly-eroding basins such as the tectonically quiescent Australian Murray-Darling or the central African Okavango and Congo rivers, 26Al/10Be ratios of millennial-scale sediment fluxes to global source areas provides an estimate of the global sediment flux. The comparison with estimates of modern sediment fluxes from river load gauging offers to deciphering the controls of sediment generation versus sediment transport across large basins. [1] Wittmann and von Blanckenburg (2016), Earth Science Reviews, 159,118-141.

  10. Target optimization for desired X-ray spectra produced by laser plasma accelerated electrons

    Science.gov (United States)

    Lobok, Maxim; Brantov, Andrey; Bychenkov, Valery

    2016-10-01

    Different regimes of electron acceleration from low-density targets are investigated using three-dimensional numerical simulations. Multiple spatial target density profiles were examined, including laser pre-pulse modified targets. The size of the plasma corona is shown to be one of the main parameters characterizing the temperature and number of hot electrons, which determine the yield of X-ray radiation and its hardness. The generation of X-ray radiation by laser accelerated electrons, which impact the converter target located behind the laser target, was studied. The X-ray spectra were computed using Monte-Carlo simulations. This work was partially supported by the Russian Foundation for Basic Research 16-02-00088-a.

  11. External injection and acceleration of electron bunch in front of the plasma wakefield produced by a periodic chirped laser pulse

    Science.gov (United States)

    Eslami, Esmaeil; Afhami, Saeedeh

    2017-01-01

    Herein, we present the analytical results on the behavior of the electron bunch injected in front of the plasma wakefield produced by a chirped laser pulse. In particular, a periodic chirped pulse may produce an ultra-relativistic electron bunch with a relatively small energy spread. The electrons are trapped near the region of the first accelerating maximum of the wakefield and are compressed in both the longitudinal and transverse directions (betatron oscillation). Our results are in good agreement with the one-dimensional results recently published.

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

    Science.gov (United States)

    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.

  13. Mechanism of fission of neutron-deficient actinoids nuclides

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  14. Production of radioactive nuclides in inverse reaction kinematics

    Energy Technology Data Exchange (ETDEWEB)

    Traykov, E.; Rogachevskiy, A.; Dammalapati, U.; Dendooven, P.; Dermois, O.C.; Jungmann, K.; Onderwater, C.J.G.; Sohani, M.; Willmann, L.; Wilschut, H.W. [KVI, Univ. of Groningen (Netherlands); Young, A. [North Carolina State Univ., Raleigh, NC (United States)

    2007-07-01

    Beams of radioactive nuclides can be produced in a variety of ways. Effcient production of short-lived radioactive isotopes in inverse reaction kinematics is an important technique for a number of applications. It is particularly interesting when the isotope is only a few nucleons away from stable isotopes. The production via charge exchange and stripping reactions has been explored at the TRI{mu}P magnetic double separator at the Kernfysisch Versneller Instituut in Groningen. The balance between separator transmission efficiency and production yield and the corresponding choice for the beam energy has been investigated. The results of some exploratory experiments at the new TRI{mu}P facility will be presented. (orig.)

  15. Measurements of accelerator-produced leakage neutron and photon transmission through concrete.

    Science.gov (United States)

    Kase, K R; Nelson, W R; Fasso, A; Liu, J C; Mao, X; Jenkins, T M; Kleck, J H

    2003-02-01

    Optimum shielding of the radiation from particle accelerators requires knowledge of the attenuation characteristics of the shielding material. The most common material for shielding this radiation is concrete, which can be made using various materials of different densities as aggregates. These different concrete mixes can have very different attenuation characteristics. Information about the attenuation of leakage photons and neutrons in ordinary and heavy concrete is, however, very limited. To increase our knowledge and understanding of the radiation attenuation in concrete of various compositions, we have performed measurements of the transmission of leakage radiation, photons and neutrons, from a Varian Clinac 2100C medical linear accelerator operating at maximum electron energies of 6 and 18 MeV. We have also calculated, using Monte Carlo techniques, the leakage neutron spectra and its transmission through concrete. The results of these measurements and calculations extend the information currently available for designing shielding for medical electron accelerators. Photon transmission characteristics depend more on the manufacturer of the concrete than on the atomic composition. A possible cause for this effect is a non-uniform distribution of the high-density aggregate, typically iron, in the concrete matrix. Errors in estimated transmission of photons can exceed a factor of three, depending on barrier thickness, if attenuation in high-density concrete is simply scaled from that of normal density concrete. We found that neutron transmission through the high-density concretes can be estimated most reasonably and conservatively by using the linear tenth-value layer of normal concrete if specific values of the tenth-value layer of the high-density concrete are not known. The reason for this is that the neutron transmission depends primarily on the hydrogen content of the concrete, which does not significantly depend on concrete density. Errors of factors of two

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

    DEFF Research Database (Denmark)

    Frohlich, Camilla; Nehammer, Camilla; Albrechtsen, Reidar

    2011-01-01

    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 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...... 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...

  17. Characterization of electrons and x-rays produced using chirped laser pulses in a laser wakefield accelerator

    Science.gov (United States)

    Zhao, T. Z.; Behm, K.; He, Z.-H.; Maksimchuk, A.; Nees, J. A.; Yanovsky, V.; Thomas, A. G. R.; Krushelnick, K.

    2016-11-01

    The electron injection process into a plasma-based laser wakefield accelerator can be influenced by modifying the parameters of the driver pulse. We present an experimental study on the combined effect of the laser pulse duration, pulse shape, and frequency chirp on the electron injection and acceleration process and the associated radiation emission for two different gas types—a 97.5% He and 2.5% N2 mixture and pure He. In general, the shortest pulse duration with minimal frequency chirp produced the highest energy electrons and the most charge. Pulses on the positive chirp side sustained electron injection and produced higher charge, but lower peak energy electrons, compared with negatively chirped pulses. A similar trend was observed for the radiant energy. The relationship between the radiant energy and the electron charge remained linear over a threefold change in the electron density and was independent of the drive pulse characteristics. X-ray spectra showed that ionization injection of electrons into the wakefield generally produced more photons than self-injection for all pulse durations/frequency chirp and had less of a spread in the number of photons around the peak x-ray energy.

  18. A dual mode pulsed electro-magnetic cell stimulator produces acceleration of myogenic differentiation.

    Science.gov (United States)

    Leon-Salas, Walter D; Rizk, Hatem; Mo, Chenglin; Weisleder, Noah; Brotto, Leticia; Abreu, Eduardo; Brotto, Marco

    2013-04-01

    This paper presents the design and test of a dual-mode electric and magnetic biological stimulator (EM-Stim). The stimulator generates pulsing electric and magnetic fields at programmable rates and intensities. While electric and magnetic stimulators have been reported before, this is the first device that combines both modalities. The ability of the dual stimulation to target bone and muscle tissue simultaneously has the potential to improve the therapeutic treatment of osteoporosis and sarcopenia. The device is fully programmable, portable and easy to use, and can run from a battery or a power supply. The device can generate magnetic fields of up to 1.6 mT and output voltages of +/- 40 V. The EM-Stim accelerated myogenic differentiation of myoblasts into myotubes as evidenced by morphometric, gene expression, and protein content analyses. Currently, there are many patents concerned with the application of single electrical or magnetic stimulation, but none that combine both simultaneously. However, we applied for and obtained a provisional patent for new device to fully explore its therapeutic potential in pre-clinical models.

  19. Studies on high-quality electron beams and tunable x-ray sources produced by laser wakefield accelerators

    Science.gov (United States)

    Zeng, Ming; Luo, Ji; Chen, Min; Sheng, Zheng-Ming

    2016-11-01

    The applications of laser wake field accelerators (LWFA) rely heavily on the quality of produced high energy electron beams and X-ray sources. We present our recent progress on this issue. Firstly we propose a bichromatic laser ionization injection scheme for obtaining high quality electron beams. With the laser pulse combinations of 800 nm and 267 nm, or 2400 nm and 800 nm in wavelengths, electron beams with energy spread of 1% or lower can be produced. Secondly we propose polarization tunable X-ray sources based on LWFA. By shooting a laser pulse into a preformed plasma channel with a skew angle referring to the channel axis, the plasma channel can act as a helical undulator for elliptically polarized X-rays.

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

    CERN Document Server

    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. Optimal reactions for synthesis of nuclides of element 108

    Institute of Scientific and Technical Information of China (English)

    Liu Zu-Hua; Zhou Hong-Yu

    2007-01-01

    The cross sections for the production of nuclides of element 108 via hot fusion evaporation reactions are studied using a two-parameter Smoluchowski equation. The optimal reactions for the synthesis of new nuclides of element 108 with mass numbers from 266 to 271 are suggested. The macroscopic-microscopic approach predicts a strong deformed shell closure at Z ≈ 108 and N = 162. The synthesis of more nuclides of element 108 is meaningful to the confirmation of the existence of this deformed shell closure.

  2. A computer code for calculation of radioactive nuclide generation and depletion, decay heat and {gamma} ray spectrum. FPGS90

    Energy Technology Data Exchange (ETDEWEB)

    Ihara, Hitoshi; Katakura, Jun-ichi; Nakagawa, Tsuneo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1995-11-01

    In a nuclear reactor radioactive nuclides are generated and depleted with burning up of nuclear fuel. The radioactive nuclides, emitting {gamma} ray and {beta} 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 {gamma} 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).

  3. Removal of radioactive nuclides by alginate microcapsules

    Energy Technology Data Exchange (ETDEWEB)

    Mimura, H.; Oritani, T.; Akiba, K. [Tohoku Univ., Institute of Multidisciplinary Research for Advanced Materials, Sendai, Miyagi (Japan)

    2002-11-01

    The microcapsules enclosing two kinds of functional materials, inorganic ion-exchangers and organic extractants, were prepared by taking advantage of the high immobilization ability of alginate gel polymer. The K{sub d} values of Cs{sup +}, Sr{sup 2+}, Co{sup 2+}, Y{sup 3+}, Eu{sup 3+} and Am{sup 3+}, for a favorable microcapsule (CuFC/clinoptilolite/DEHPA/CaALG) were estimated to be 1.1x10{sup 4}, 7.5x10, 1.1x10, 1.0x10{sup 4}, 1.4x10{sup 4}, 3.4x10{sup 3} cm{sup 3}/g, respectively. The microcapsules with various shapes such as spherical, columnar, fibrous and filmy forms were easily prepared by changing the way of dipping kneaded sol into the gelling salt solutions. The alginate microcapsules have a potential possibility for the simultaneous removal of various radioactive nuclides from waste solutions. (author)

  4. Acceleration of protons in plasma produced from a thin plastic or aluminum target by a femtosecond laser

    Science.gov (United States)

    Rosinski, M.; Badziak, J.; Parys, P.; Zaras-Szydlowska, A.; Ryc, L.; Torrisi, L.; Szydlowski, A.; Malinowska, A.; Kaczmarczyk, B.; Makowski, J.; Torrisi, A.

    2016-05-01

    The acceleration of protons in plasma produced from thin mylar (3.5 μ m) and aluminum (2 μm) targets by a 45-fs laser pulses with the energy of 400 mJ and the intensity of up to 1019 W/cm2 was investigated. Characteristics of forward-accelerated protons were measured by the time-of-flight method. In the measurements, special attention was paid to the dependence of proton beam parameters on the laser focus position (FP) in relation to the target surface which resulted in the intensity change within a factor of ~ 10. It was observed that in the case of using the Mylar target, the dependence of both the maximum (Epmax) and the mean (langleEprangle) proton energy on |Δx| is clearly non-symmetric with regard to the point where FP = 0 (the focal plane on the target surface) and highest proton energies are achieved when the focal plane is situated in front of the target. In particular, for the target with the thickness of 3.5 μ m Epmax reached 2.2 MeV for FP = +50 μm while for FP = 0 and FP = -100 μm the maximum proton energies reached only 1.6 MeV and 1.3 MeV, respectively. For the aluminum target of 2 μm thickness Ep changed only within ~ 40% and the highest proton energies reached 2.4 MeV.

  5. Accelerated formation of hydrogen-producing granules for the start-up of UASB reactors using vinasses

    Directory of Open Access Journals (Sweden)

    César González-Ugalde

    2014-02-01

    Full Text Available Hydrogen-producing granules formation was studied in a CSTR. The aim of this process is to later transfer the mixed liquor to a UASB reactor to reduce its start-up period. Vinasses from a national bioetha­nol-producing industry (from sugar cane were used as substrate and their anaerobic fermentation was carried out under mesophilic conditions. The seed sludge was collected from an UASB reactor oper­ated in an industrial wastewater treatment plant and it was heat treated to inactivate methanogenic bacteria. Total viable and non-viable material growth curves were generated and it was determined that the exponential growth phase of the thermally pre­treated mixed culture was between 20 and 120 h. Finally, the anaerobic fermentation of the vinasses in batch mode for 70 hours, and then in continuous CSTR mode for 7 days, showed to be an effective method for accelerating the formation of hydrogen-producing granules. Using this method, granules with an average size of 1.24 mm were achieved. The good efficiency of the process is attributed to high mass transfer in the CSTR reactor.

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

    Science.gov (United States)

    Lambert, Max R.

    2015-01-01

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Kondrashov, V.S. E-mail: vlkondra@cdrewu.edu; Rothenberg, S.J.; Petersone, I

    2001-09-11

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  9. Algorithm improvement program nuclide identification algorithm scoring criteria and scoring application.

    Energy Technology Data Exchange (ETDEWEB)

    Enghauser, Michael [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-02-01

    The goal of the Domestic Nuclear Detection Office (DNDO) Algorithm Improvement Program (AIP) is to facilitate gamma-radiation detector nuclide identification algorithm development, improvement, and validation. Accordingly, scoring criteria have been developed to objectively assess the performance of nuclide identification algorithms. In addition, a Microsoft Excel spreadsheet application for automated nuclide identification scoring has been developed. This report provides an overview of the equations, nuclide weighting factors, nuclide equivalencies, and configuration weighting factors used by the application for scoring nuclide identification algorithm performance. Furthermore, this report presents a general overview of the nuclide identification algorithm scoring application including illustrative examples.

  10. Vestibular evoked potentials (VsEPs) of cortical origin produced by impulsive acceleration applied at the nasion.

    Science.gov (United States)

    Todd, Neil P M; McLean, Aisha; Paillard, Aurore; Kluk, Karolina; Colebatch, James G

    2014-12-01

    We report the results of a study to record vestibular evoked potentials (VsEPs) of cortical origin produced by impulsive acceleration (IA). In a sample of 12 healthy participants, evoked potentials recorded by 70 channel electroencephalography were obtained by IA stimulation at the nasion and compared with evoked potentials from the same stimulus applied to the forefingers. The nasion stimulation gave rise to a series of positive and negative deflections in the latency range of 26-72 ms, which were dependent on the polarity of the applied IA. In contrast, evoked potentials from the fingers were characterised by a single N50/P50 deflection at about 50 ms and were polarity invariant. Source analysis confirmed that the finger evoked potentials were somatosensory in origin, i.e. were somatosensory evoked potentials, and suggested that the nasion evoked potentials plausibly included vestibular midline and frontal sources, as well as contributions from the eyes, and thus were likely VsEPs. These results show considerable promise as a new method for assessment of the central vestibular system by means of VsEPs produced by IA applied to the head.

  11. Data Evaluation Acquired Talys 1.0 Code to Produce 111In from Various Accelerator-Based Reactions

    Science.gov (United States)

    Alipoor, Zahra; Gholamzadeh, Zohreh; Sadeghi, Mahdi; Seyyedi, Solaleh; Aref, Morteza

    The Indium-111 physical-decay parameters as a β-emitter radionuclide show some potential for radiodiagnostic and radiotherapeutic purposes. Medical investigators have shown that 111In is an important radionuclide for locating and imaging certain tumors, visualization of the lymphatic system and thousands of labeling reactions have been suggested. The TALYS 1.0 code was used here to calculate excitation functions of 112/114-118Sn+p, 110Cd+3He, 109Ag+3He, 111-114Cd+p, 110/111Cd+d, 109Ag+α to produce 111In using low and medium energy accelerators. Calculations were performed up to 200 MeV. Appropriate target thicknesses have been assumed based on energy loss calculations with the SRIM code. Theoretical integral yields for all the latter reactions were calculated. The TALYS 1.0 code predicts that the production of a few curies of 111In is feasible using a target of isotopically highly enriched 112Cd and a proton energy between 12 and 25 MeV with a production rate as 248.97 MBq·μA-1 · h-1. Minimum impurities shall be produced during the proton irradiation of an enriched 111Cd target yielding a production rate for 111In of 67.52 MBq· μA-1 · h-1.

  12. Inventory simulation tools: Separating nuclide contributions to radiological quantities

    Directory of Open Access Journals (Sweden)

    Gilbert Mark R.

    2017-01-01

    Full Text Available The activation response of a material is a primary factor considered when evaluating its suitability for a nuclear application. Various radiological quantities, such as total (becquerel activity, decay heat, and γ dose, can be readily predicted via inventory simulations, which numerically evolve in time the composition of a material under exposure to neutron irradiation. However, the resulting data sets can be very complex, often necessarily resulting in an over-simplification of the results – most commonly by just considering total response metrics. A number of different techniques for disseminating more completely the vast amount of data output from, in particular, the FISPACT-II inventory code system, including importance diagrams, nuclide maps, and primary knock-on atom (PKA spectra, have been developed and used in scoping studies to produce database reports for the periodic table of elements. This paper introduces the latest addition to this arsenal – standardised and automated plotting of the time evolution in a radiological quantity for a given material separated by contributions from dominant radionuclides. Examples for relevant materials under predicted fusion reactor conditions, and for bench-marking studies against decay-heat measurements, demonstrate the usefulness and power of these radionuclide-separated activation plots.

  13. Inventory simulation tools: Separating nuclide contributions to radiological quantities

    Science.gov (United States)

    Gilbert, Mark R.; Fleming, Michael; Sublet, Jean-Christophe

    2017-09-01

    The activation response of a material is a primary factor considered when evaluating its suitability for a nuclear application. Various radiological quantities, such as total (becquerel) activity, decay heat, and γ dose, can be readily predicted via inventory simulations, which numerically evolve in time the composition of a material under exposure to neutron irradiation. However, the resulting data sets can be very complex, often necessarily resulting in an over-simplification of the results - most commonly by just considering total response metrics. A number of different techniques for disseminating more completely the vast amount of data output from, in particular, the FISPACT-II inventory code system, including importance diagrams, nuclide maps, and primary knock-on atom (PKA) spectra, have been developed and used in scoping studies to produce database reports for the periodic table of elements. This paper introduces the latest addition to this arsenal - standardised and automated plotting of the time evolution in a radiological quantity for a given material separated by contributions from dominant radionuclides. Examples for relevant materials under predicted fusion reactor conditions, and for bench-marking studies against decay-heat measurements, demonstrate the usefulness and power of these radionuclide-separated activation plots. Note to the reader: the pdf file has been changed on September 22, 2017.

  14. Progress on multi-nuclide AMS of JAEA-AMS-TONO

    Energy Technology Data Exchange (ETDEWEB)

    Saito-Kokubu, Yoko, E-mail: kokubu.yoko@jaea.go.jp [Japan Atomic Energy Agency, Toki, Gifu 509-5102 (Japan); Matsubara, Akihiro [Japan Atomic Energy Agency, Toki, Gifu 509-5102 (Japan); Miyake, Masayasu; Nishizawa, Akimitsu; Ohwaki, Yoshio; Nishio, Tomohiro; Sanada, Katsuki [Pesco Corp., Ltd., Toki, Gifu 509-5123 (Japan); Hanaki, Tatsumi [Japan Atomic Energy Agency, Toki, Gifu 509-5102 (Japan)

    2015-10-15

    The JAEA-AMS-TONO (Japan Atomic Energy Agency’s Accelerator Mass Spectrometer established at the Tono Geoscience Center) facility has been used for the dating of geological samples. The AMS system is versatile, based on a 5 MV tandem Pelletron-type accelerator. Since its establishment in 1997, the AMS system has been used for measurement of carbon-14 ({sup 14}C) mainly for {sup 14}C dating studies in neotectonics and hydrogeology, in support of JAEA’s research on geosphere stability applicable to the long-term isolation of high-level radioactive waste. Results of the measurement of {sup 14}C in soils and plants has been applied to the dating of fault activity and volcanism. Development of beryllium-10 ({sup 10}Be) and aluminum-26 ({sup 26}Al) AMS systems are now underway to enhance the capability of the multi-nuclide AMS in studies of dating by cosmogenic nuclides. The {sup 10}Be-AMS system has already been used for routine measurements in applied studies and improvements of the measurement technique have been made. Now we plan to fine tune the system and perform test measurements to develop the {sup 26}Al-AMS system.

  15. 600 MeV Simulation of the Production of Cosmogenic Nuclides in Meteorites by Galactic Protons

    CERN Multimedia

    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...

  16. The Gas-Filled-Magnet at PRIME Lab: Increased Sensitivity of Cosmogenic Nuclide Measurements

    Science.gov (United States)

    Caffee, M. W.; Granger, D. E.; Woodruff, T. E.

    2015-12-01

    Abstract: Using accelerator mass spectrometry (AMS), radionuclides produced either by cosmic-ray interactions or by nucleogenic means can be measured. Typical isotopic abundance ratios range from 1 x 10-10 to 1 x 10-15. The routinely measured radionuclides are 10Be, 14C, 26Al, 36Cl, and 129I. Be-10, 26Al, and 36Cl have isobaric interferences that cannot be eliminated mass through mass analysis, but dE/dx techniques suppresses these isobars enough to allow successful measurements. There are compromises, the isobar for 26Al, 26Mg, precludes successful measurement of 26Al if AlO- is injected into the accelerator. Mg- doesn't form a stable negative ion so a 26Al measurement requires injection of 26Al-. But the Al- ion is formed inefficiently; secondary ion currents using Al- are ~ 10 times less than an AlO- secondary ion beam. Precision scales with count rate so precise measurement of the 26Al/Al for all but higher ratio samples is difficult. It has long been recognized that a gas-filled-magnet (GFM) could potentially improve the measurement of those radionuclides with intractable isobar interferences. A GFM works on the principle that each element of an isobar pair, e.g. 26Mg and 26Al, has a different average charge state as it traverses a gas (3-4 Torr of N2) contained within the vacuum jacket of a magnet. The magnet steers each species with its own momentum-to-charge ratio on its own distinct radius of curvature. The magnet can be tuned to allow the isotope of interest into a dE/dx detector; most of the isobar doesn't make it into the detector. Using the PRIME Lab GFM we are now able to routinely run 26Al with a precision that is comparable to that obtained with 10Be. We are also using the GFM for routine measurements of 10Be and 36Cl. Although the improvement for these nuclides is not as pronounced as it is for 26Al, the GFM has improved the detection sensitivity for both. Our 10Be background is now ~ 5 x 10-16 and for 36Cl we can now run the source more

  17. Effects of bulk composition on nuclide production processes in meteorites

    Energy Technology Data Exchange (ETDEWEB)

    Masarik, J.; Reedy, R.C. [Los Alamos National Lab., NM (United States)

    1994-12-01

    The bulk chemical composition of meteorites is a major factor influencing the production of cosmogenic nuclides. Numerical simulations using Monte Carlo particle production and transport codes were used to investigate particle fluxes, {sup 38}Ar elemental production ratios, and {sup 21}Ne/{sup 22}Ne ratios in meteorites with a wide range of compositions. The calculations show that enhanced fluxes of low-energy secondary particles in metal-rich phases explain certain experimentally observed differences in nuclide production in various meteorite classes.

  18. Accelerator-Driven Subcritical Fission in a Molten Salt Core: Green Nuclear Power for the New Millennium

    Science.gov (United States)

    McIntyre, Peter

    2011-10-01

    Scientists at Texas A&M University, Brookhaven National Lab, and Idaho National Lab are developing a design for accelerator-drive subcritical fission in a molten salt core (ADSMS). Three high-power proton beams are delivered to spallation targets in a molten salt core, where they provide ˜3% of the fast neutrons required to sustain 600 MW of fission. The proton beams are produced by a flux-coupled stack of superconducting strong-focusing cyclotrons. The fuel consists of a eutectic of sodium chloride with either spent nuclear fuel from a conventional U power reactor (ADSMS-U) or thorium (ADSMS-Th). The subcritical core cannot go critical under any failure mode. The core cannot melt down even if all power is suddenly lost to the facility for a prolonged period. The ultra-fast neutronics of the core makes it possible to operate in an isobreeding mode, in which neutron capture breeds the fertile nuclide into a fissile nuclide at the same rate that fission burns the fissile nuclide, and consumes 90% of the fertile inventory instead of the 5% consumed in the original use in a conventional power plant. The ultra-fast neutronics produces a very low equilibrium inventory of the long-lived minor actinides, ˜10^4 less than what is produced in conventional power plants. ADSMS offers a method to safely produce the energy needs for all mankind for the next 3000 years.

  19. Prompt neutron fission spectrum mean energies for the fissile nuclides and /sup 252/Cf

    Energy Technology Data Exchange (ETDEWEB)

    Holden, N.E.

    1985-01-01

    The international standard for a neutron spectrum is that produced from the spontaneous fission of /sup 252/Cf, while the thermal neutron induced fission neutron spectra for the four fissile nuclides, /sup 233/U, /sup 235/U, /sup 239/Pu, and /sup 241/Pu are of interest from the standpoint of nuclear reactors. The average neutron energies of these spectra are tabulated. The individual measurements are recorded with the neutron energy range measured, the method of detection as well as the average neutron energy for each author. Also tabulated are the measurements of the ratio of mean energies for pairs of fission neutron spectra. 75 refs., 9 tabs. (LEW)

  20. Synthesize Neutron-Drip-Line-Nuclides with Free-Neutron Bose-Einstein Condensates Experimentally

    CERN Document Server

    Dong, Bao-Guo

    2014-01-01

    We first show a possible way to create a new type of matter, free-neutron Bose-Einstein condensate by the ultracold free-neutron-pair Bose-Einstein condensation and then determine the neutron drip line experimentally. The Bose-Einstein condensation of bosonic and fermionic atoms in atomic gases was performed experimentally and predicted theoretically early. Neutrons are similar to fermionic atoms. We found free neutrons could be cooled to ultracold neutrons with very low energy by other colder neutral atoms which are cooled by the laser. These neutrons form neutron pairs with spin zero, and then ultracold neutron-pairs form Bose-Einstein condensate. Our results demonstrate how these condensates can react with accelerated ion beams at different energy to synthesize very neutron-rich nuclides near, on or/and beyond the neutron drip line, to determine the neutron drip line and whether there are long-life nuclide or isomer islands beyond the neutron drip line experimentally. Otherwise, these experimental results ...

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

    Science.gov (United States)

    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.

  2. Quantifying nuclide contributions to reactor behaviour over time

    NARCIS (Netherlands)

    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

  3. Radiometric dating by alpha spectrometry on uranium series nuclides

    NARCIS (Netherlands)

    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 ho

  4. Quantifying nuclide contributions to reactor behaviour over time

    NARCIS (Netherlands)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Longcheng Liu

    2001-12-01

    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 H{sub 2}, using UO{sub 2} (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 H{sub 2} on the fuel surface. It will reprecipitate as UO{sub 2} (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 H{sub 2} 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

  6. Targeted Alpha Therapy: The US DOE Tri-Lab (ORNL, BNL, LANL) Research Effort to Provide Accelerator-Produced 225Ac for Radiotherapy

    Science.gov (United States)

    John, Kevin

    2017-01-01

    Targeted radiotherapy is an emerging discipline of cancer therapy that exploits the biochemical differences between normal cells and cancer cells to selectively deliver a lethal dose of radiation to cancer cells, while leaving healthy cells relatively unperturbed. A broad overview of targeted alpha therapy including isotope production methods, and associated isotope production facility needs, will be provided. A more general overview of the US Department of Energy Isotope Program's Tri-Lab (ORNL, BNL, LANL) Research Effort to Provide Accelerator-Produced 225Ac for Radiotherapy will also be presented focusing on the accelerator-production of 225Ac and final product isolation methodologies for medical applications.

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

    Science.gov (United States)

    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.

  8. A comparison of rat SPECT images obtained using (99m)Tc derived from 99Mo produced by an electron accelerator with that from a reactor.

    Science.gov (United States)

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

    2013-05-07

    Recent shortages of molybdenum-99 ((99)Mo) 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 (99)Mo from which technetium-99m ((99m)Tc) is extracted. SPECT images of rat anatomy obtained using the accelerator-produced (99m)Tc with those obtained using (99m)Tc from a commercial generator were compared. Disks of (100)Mo were irradiated with x-rays produced by a 35 MeV electron beam to generate about 1110 MBq (30 mCi) of (99)Mo per disk. After target dissolution, a NorthStar ARSII unit was used to separate the (99m)Tc, 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 (99m)Tc from a standard reactor (99)Mo generator. The efficiency of (99)Mo-(99m)Tc separation was typically greater than 90%. This study demonstrated the delivery of (99m)Tc 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 (99m)Tc were comparable. High-power electron accelerators are an attractive option for producing (99)Mo on a national scale.

  9. Accelerated radiation damage test facility using a 5 MV tandem ion accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Wady, P.T., E-mail: paul.wady@manchester.ac.uk [Dalton Cumbrian Facility, University of Manchester, Westlakes Science & Technology Park, Moor Row, Cumbria CA24 3HA (United Kingdom); Draude, A.; Shubeita, S.M.; Smith, A.D.; Mason, N. [Dalton Cumbrian Facility, University of Manchester, Westlakes Science & Technology Park, Moor Row, Cumbria CA24 3HA (United Kingdom); Pimblott, S.M. [Dalton Cumbrian Facility, University of Manchester, Westlakes Science & Technology Park, Moor Row, Cumbria CA24 3HA (United Kingdom); School of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Jimenez-Melero, E. [Dalton Cumbrian Facility, University of Manchester, Westlakes Science & Technology Park, Moor Row, Cumbria CA24 3HA (United Kingdom); School of Materials, University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom)

    2016-01-11

    We have developed a new irradiation facility that allows to perform accelerated damage tests of nuclear reactor materials at temperatures up to 400 °C using the intense proton (<100 μA) and heavy ion (≈10 μA) beams produced by a 5 MV tandem ion accelerator. The dedicated beam line for radiation damage studies comprises: (1) beam diagnosis and focusing optical components, (2) a scanning and slit system that allows uniform irradiation of a sample area of 0.5–6 cm{sup 2}, and (3) a sample stage designed to be able to monitor in-situ the sample temperature, current deposited on the sample, and the gamma spectrum of potential radio-active nuclides produced during the sample irradiation. The beam line capabilities have been tested by irradiating a 20Cr–25Ni–Nb stabilised stainless steel with a 3 MeV proton beam to a dose level of 3 dpa. The irradiation temperature was 356 °C, with a maximum range in temperature values of ±6 °C within the first 24 h of continuous irradiation. The sample stage is connected to ground through an electrometer to measure accurately the charge deposited on the sample. The charge can be integrated in hardware during irradiation, and this methodology removes uncertainties due to fluctuations in beam current. The measured gamma spectrum allowed the identification of the main radioactive nuclides produced during the proton bombardment from the lifetimes and gamma emissions. This dedicated radiation damage beam line is hosted by the Dalton Cumbrian Facility of the University of Manchester.

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

    Science.gov (United States)

    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

  11. Age determination of meteorites using radioactive nuclides

    Energy Technology Data Exchange (ETDEWEB)

    Tanimizu, Masaharu [Tokyo Institute of Technology, Graduate School of Science and Engineering, Department of Earth and Planetary Sciences, Tokyo (Japan)

    2002-07-01

    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 {sup 182}Hf (T{sub 1/2}=9 Myr), which was produced at the latest nucleosynthesis, is recognized in many meteorites as isotopic anomalies of its daughter isotope, {sup 182}W. The degrees of relative {sup 182}W 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 {sup 182}Hf, equivalent to 36 Myr. (author)

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

    Science.gov (United States)

    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.

  13. Mass Measurements on Short-Lived Nuclides with ISOLTRAP

    Energy Technology Data Exchange (ETDEWEB)

    Bollen, G. [Michigan State University, National Superconducting Cyclotron Laboratory (United States); Ames, F. [Universitaet Mainz, Institut fuer Physik (Germany); Audi, G. [Universite Paris-Sud, CSNSM-IN2P3-CNRS (France); Beck, D.; Dilling, J. [GSI (Germany); Engels, O. [LMU (Germany); Henry, S. [Universite Paris-Sud, CSNSM-IN2P3-CNRS (France); Herfurth, F.; Kellerbauer, A.; Kluge, H.-J.; Kohl, A.; Lamour, E. [GSI (Germany); Lunney, D. [Universite Paris-Sud, CSNSM-IN2P3-CNRS (France); Moore, R. B. [LMU (Germany); Oinonen, M. [CERN, EP Division (Switzerland); Scheidenberger, C. [GSI (Germany); Schwarz, S. [Michigan State University, National Superconducting Cyclotron Laboratory (United States); Sikler, G. [GSI (Germany); Szerypo, J. [JYFL (Finland); Weber, C. [GSI (Germany)

    2001-01-15

    Penning trap mass spectrometry has reached a state that allows its application to very short-lived nuclides available from various sources of radioactive beams. Mass values with outstanding accuracy are achieved even far from stability. This paper illustrates the state of the art by summarizing the status of the ISOLTRAP experiment at ISOLDE/CERN. Furthermore, results of mass measurements on unstable rare earth isotopes will be given.

  14. Hot demonstration of proposed commercial nuclide removal technology

    Energy Technology Data Exchange (ETDEWEB)

    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.

  15. Radiometric dating by alpha spectrometry on uranium series nuclides

    OpenAIRE

    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...

  16. Measurements of neutron cross sections of radioactive waste nuclides

    Energy Technology Data Exchange (ETDEWEB)

    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)

  17. Immunological priming requires regulatory T cells and IL-10-producing macrophages to accelerate resolution from severe lung inflammation.

    Science.gov (United States)

    Aggarwal, Neil R; Tsushima, Kenji; Eto, Yoshiki; Tripathi, Ashutosh; Mandke, Pooja; Mock, Jason R; Garibaldi, Brian T; Singer, Benjamin D; Sidhaye, Venkataramana K; Horton, Maureen R; King, Landon S; D'Alessio, Franco R

    2014-05-01

    Overwhelming lung inflammation frequently occurs following exposure to both direct infectious and noninfectious agents and is a leading cause of mortality worldwide. In that context, immunomodulatory strategies may be used to limit severity of impending organ damage. We sought to determine whether priming the lung by activating the immune system, or immunological priming, could accelerate resolution of severe lung inflammation. We assessed the importance of alveolar macrophages, regulatory T cells, and their potential interaction during immunological priming. We demonstrate that oropharyngeal delivery of low-dose LPS can immunologically prime the lung to augment alveolar macrophage production of IL-10 and enhance resolution of lung inflammation induced by a lethal dose of LPS or by Pseudomonas bacterial pneumonia. IL-10-deficient mice did not achieve priming and were unable to accelerate lung injury resolution. Depletion of lung macrophages or regulatory T cells during the priming response completely abrogated the positive effect of immunological priming on resolution of lung inflammation and significantly reduced alveolar macrophage IL-10 production. Finally, we demonstrated that oropharyngeal delivery of synthetic CpG-oligonucleotides elicited minimal lung inflammation compared with low-dose LPS but nonetheless primed the lung to accelerate resolution of lung injury following subsequent lethal LPS exposure. Immunological priming is a viable immunomodulatory strategy used to enhance resolution in an experimental acute lung injury model with the potential for therapeutic benefit against a wide array of injurious exposures.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  19. Stereoscopic camera and viewing systems with undistorted depth presentation and reduced or eliminated erroneous acceleration and deceleration perceptions, or with perceptions produced or enhanced for special effects

    Science.gov (United States)

    Diner, Daniel B. (Inventor)

    1991-01-01

    Methods for providing stereoscopic image presentation and stereoscopic configurations using stereoscopic viewing systems having converged or parallel cameras may be set up to reduce or eliminate erroneously perceived accelerations and decelerations by proper selection of parameters, such as an image magnification factor, q, and intercamera distance, 2w. For converged cameras, q is selected to be equal to Ve - qwl = 0, where V is the camera distance, e is half the interocular distance of an observer, w is half the intercamera distance, and l is the actual distance from the first nodal point of each camera to the convergence point, and for parallel cameras, q is selected to be equal to e/w. While converged cameras cannot be set up to provide fully undistorted three-dimensional views, they can be set up to provide a linear relationship between real and apparent depth and thus minimize erroneously perceived accelerations and decelerations for three sagittal planes, x = -w, x = 0, and x = +w which are indicated to the observer. Parallel cameras can be set up to provide fully undistorted three-dimensional views by controlling the location of the observer and by magnification and shifting of left and right images. In addition, the teachings of this disclosure can be used to provide methods of stereoscopic image presentation and stereoscopic camera configurations to produce a nonlinear relation between perceived and real depth, and erroneously produce or enhance perceived accelerations and decelerations in order to provide special effects for entertainment, training, or educational purposes.

  20. Production Rates of Cosmogenic Nuclides Deep in the Moon

    Science.gov (United States)

    Reedy, R. C.; Masarik, J.

    1995-09-01

    Measurements of radionuclide activities in Apollo samples extend to depths of only about 400 g/cm2 in the Moon. Some Apollo samples and lunar meteorites probably have significant concentrations of cosmogenic nuclides made while they were buried at depths greater than 400 g/cm2. We report here initial calculations for production rates of cosmogenic nuclides for depths in the Moon down to 1500 g/cm2. The LAHET Code System (LCS) [1] was used to numerically simulate the irradiation of the Moon by galactic-cosmic-ray particles and to calculate particle fluxes and production rates of various cosmogenic nuclides. The advantage of these calculations is that the LCS physical model used for the production and transport of particles in the Moon has no free parameters. Some previous models, such as Reedy and Arnold (1972) [2], had semi-empirical or adopted parameters that never were tested below about 400 g/cm2. Our simulations started by selecting the energy and direction of the primary particle that starts a particle cascade and following all particles until they are removed by nuclear interactions or escape from the Moon. The calculations were validated by modeling production of 10Be, 26Al, 36Cl, and 53Mn in the Apollo 15 drill core and getting good agreement with measurements to depths of about 400 g/cm2 [3]. We used the composition of the Apollo 15 deep drill core for these calculations, assumed a density of 1.5 g/cm3, and did calculations to a depth of 1000 cm (1500 g/cm2). We ran 5 million incident particles to try to get good statistics at great depths. Statistical uncertainties for depths below about 1000 g/cm2 were about 10%, so we splined the results for depths below 750 g/cm2. We reproduced our original results [3] down to 500 g/cm2, extended the calculated production rates of those four radionuclides to 1500 g/cm2, and also calculated production rates of 14C, 21Ne, 22Ne, and 38Ar from 0 to 1500 g/cm2. As reported earlier [3], production rates for various

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  2. Recent developments and on-line tests of uranium carbide targets for production of nuclides far from stability

    CERN Document Server

    Panteleev, V.N; Barzakh, A.E; Fedorov, D.V; Ionan, A.M; Ivanov, V.S; Mezilev, K.A; Molkanov, P.L; Moroz, F.V; Orlov, S.Yu; Volkov, Yu.M; Alyakrinskiy, O; Lanchais, A; Lau, C; Lhersonneau, G; Rizzi, V; Stroe, L; Tecchio, L.B; Dubois, M; Eleon, C; Gaubert, G; Jardin, P; Saint Laurent, M.G; Villari, A.C.C; Essabaa, S; O. Bajeat; Mhamed, C; Leroy, R; 10.1140/epjst/e2007-00328-y

    2007-01-01

    The capacity of uranium carbide target materials of different structure and density for production of neutron-rich and heavy neutron-deficient nuclides have been investigated. The yields of Cs and Fr produced by a 1 GeV proton beam of the PNPI synchrocyclotron and release properties of different targets have been measured. The comparison of the yields and release efficiencies of Cs and Fr produced from a high density UC target material and from low density UCx prepared by the ISOLDE method at IRIS in the collaboration with PARRNe group from Orsay are presented. The yields from ISOLDE original target are presented for comparison as well.

  3. New mass measurements of neutron rich nuclides at the NSCL.

    Science.gov (United States)

    Estrade, Alfredo; Matos, Milan; Amthor, Matthew; Bazin, Daniel; Becerril, Ana; Elliot, Thom; Gade, Alexandra; Galaviz, Daniel; Lorusso, Giuseppe; Pereira, Jorge; Portillo, Mauricio; Rogers, Andrew; Schatz, Hendrik; Shapira, Dan; Smith, Ed; Stolz, Andreas; Wallace, Mark

    2007-10-01

    A mass measurement of exotic isotopes in the region of 68Fe has been performed at the NSCL using the time-of-flight technique recently established. Experimental knowledge of the mass of very neutron rich nuclides is an important input for astrophysical applications, such as nucleosynthesis during the r-process and the evolution of matter in the crust of an accreting neutron star, where present calculations are mostly limited to using theoretical mass extrapolations. We present the details of the experimental set up, as well as preliminary results.

  4. Time-of-Flight Mass Measurements of Neutron Rich Nuclides

    Science.gov (United States)

    Estrade, A.; Matos, M.; Amthor, A. M.; Becerril, A.; Elliot, T.; Lorusso, G.; Rogers, A.; Schatz, H.; Bazin, D.; Gade, A.; Portillo, M.; Stolz, A.; Galaviz, D.; Pereira, J.; Shapira, D.; Smith, E.; Wallace, M.

    2008-10-01

    Nuclear masses of neutron rich isotopes in the region of Z ˜ 20-30 have been measured using the time-of-flight technique at the National Superconducting Cyclotron Laboratory (NSCL). The masses of 5 isotopes have been measured for the first time, and the precision of several other masses has been improved. The time-of-flight technique has shown the potential to access nuclear masses very far from stability when applied at radioactive beam facilities like the NSCL. Such measurements are important for understanding nuclear structure far from the valley of β-stability, and provide valuable information for astrophysical model calculations of processes involving very unstable nuclides.

  5. Validation of spent nuclear fuel nuclide composition data using percentage differences and detailed analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Man Cheol [Chung-Ang Univ., Seoul (Korea, Republic of). School of Energy Systems Engineering

    2017-06-15

    Nuclide composition data of spent nuclear fuels are important in many nuclear engineering applications. In reactor physics, nuclear reactor design requires the nuclide composition and the corresponding cross sections. In analyzing the radiological health effects of a severe accident on the public and the environment, the nuclide composition in the reactor inventory is among the important input data. Nuclide composition data need to be provided to analyze the possible environmental effects of a spent nuclear fuel repository. They will also be the basis for identifying the origin of unidentified spent nuclear fuels or radioactive materials.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. Validation of cosmogenic nuclide production rate scaling factors through direct measurement

    CERN Document Server

    Graham, I J; Ditchburn, R G; Whitehead, N E

    2000-01-01

    sup 7 Be produced in water targets by nuclear interactions of cosmic rays has been measured to determine cosmogenic nuclide production rates as a function of altitude (sea level to 2 km) and geomagnetic latitude (20-79 deg. S). Relative intensities of low energy cosmic ray neutrons have at the same time been measured using neutron monitors based on IGY/NM-64 designed to efficiently thermalise ca. 2-30 MeV neutrons. The research is on-going and we present here preliminary data from the past two years. Water target and neutron flux results are in general agreement, and are consistent with the altitude-dependent scaling factors of Lal [Earth Planet. Sci. Lett. 104 (1991) 4241]. Significant differences between the sea level, latitude-dependent neutron flux data and Lal's predictions are possibly related to the response function of the detector.

  8. Forbush decreases geomagnetic and atmospheric effects cosmogenic nuclides

    Science.gov (United States)

    Flueckiger, E. O.

    1986-01-01

    An overview and synthesis is given of recent developments that have occurred in the areas of Forbush decreases, geomagnetic and atmospheric effects, and cosmogenic nuclides. Experimental evidence has been found for substantial differences in the effects of the various types of interplanetary perturbations on cosmic rays, and for a dependence of these effects on the three-dimensional configuration of the interplanetary medium. In order to fully understand and to be able to simulate the solar cosmic ray particle access to the polar regions of the earth we need accurate models of the magnetospheric magnetic field. These models must include all major magnetospheric current systems (in particular the field aligned currents), and they should represent magnetically quiet time periods as well as different levels of geomagnetic activity. In the evolution of magnetospheric magnetic field models, cosmic ray and magnetospheric physicists should work closely together since cosmic ray measurements are a powerful additional tool in the study of the perturbed magnetosphere. In the field of cosmogenic nuclides, finally, exciting new results and developments follow in rapid succession. Thanks to new techniques and new isotopes the analysis of cosmic ray history has entered into a new dimension.

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

    Science.gov (United States)

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

    2016-06-06

    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.

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

    CERN Multimedia

    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...

  11. Evaluation of internal and external doses from $^{11}C$ produced in the air in high energy proton accelerator tunnels

    CERN Document Server

    Endo, A; Kanda, Y; Oishi, T; Kondo, K

    2001-01-01

    Air has been irradiated with high energy protons at the 12 GeV proton synchrotron to obtain the following parameters essential for the internal dose evaluation from airborne /sup 11/C produced through nuclear spallation reactions: the abundance of gaseous and particulate /sup 11/C, chemical forms, and particle size distribution. It was found that more than 98% of /sup 11/C is present as gas and the rest is aerosol. The gaseous components were only /sup 11/CO and /sup 11/CO/sub 2/ and their proportions were approximately 80% and 20%, respectively. The particulate /sup 11/C was found to be sulphate and/or nitrate aerosols having a log-normal size distribution; the measurement using a diffusion battery showed a geometric mean radius of 0.035 mu m and a geometric standard deviation of 1.8 at a beam intensity of 6.8*10/sup 11/ proton.pulse /sup -1/ and an irradiation time of 9.6 min. By taking the chemical composition and particle size into account, effective doses both from internal and from external exposures pe...

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

    CERN Document Server

    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 ...

  13. Cosmogenic nuclide dating of glaciofluvial deposits: insights from the Alps

    Science.gov (United States)

    Akcar, Naki; Ivy-Ochs, Susan; Alfimov, Vasily; Claude, Anne; Reber, Regina; Christl, Marcus; Vockenhuber, Christof; Schlunegger, Fritz; Rahn, Meinert; Dehnert, Andreas; Schlüchter, Christian

    2015-04-01

    Cosmogenic 10Be and 26Al can be employed to reconstruct the chronology of sediment layers. Accumulation of these can be used to exposure date the sediment layer as the variation of cosmogenic nuclide concentration with depth can be modeled. Decay of 10Be and 26Al in the samples from a well-defined single bed in a deposit enables the modeling of the post-burial component and the determination of the 26Al/10Be at the time of burial. The isochron-burial age can then be calculated from the initial and the measured ratios. In this study, we focus on the depth-profile and isochron-burial dating of the oldest Quaternary deposits of the Alpine Foreland. These are called Swiss Deckenschotter (cover gravels) as they build mesa-type hill tops on the Mesozoic or Cenozoic bedrock of the Swiss Alpine forelands. Deckenschotter consists of glaciofluvial gravel layers intercalated with glacial and/or overbank deposits. Although previously morphostratigraphically correlated with Günz and Mindel glaciations of Penck and Brückner, the Swiss Deckenschotter is likely much older, and their chronostratigraphy is not well constrained. In order to reconstruct the chronology of these deposits, we studied two Deckenschotter outcrops in abandoned gravel pits in Mandach (507 m a.s.l.) and Siglistorf (530 m a.s.l.) in canton Zurich. We collected four samples from Mandach for 10Be analysis and more than 30 clasts of different lithology, shape and size from a single stratigraphic horizon in Siglistorf among which we processed 19 clasts for 10Be and 26Al analysis. 10Be concentrations of the Mandach samples vary between 10000 and 30000 at/g. Based on these, we calculated a modal depth-profile age of around 1.0 Ma. Among Siglistorf samples, four did not yield successful 26Al measurements and two were unsuccessful for 10Be. Most of the samples have low nuclide concentrations, i.e. <20000 10Be at/g and <150000 26Al at/g. The 26Al/10Be ratio of eight samples was above the surface ratio of 6

  14. Dosimetric characteristics of electron beams produced by two mobile accelerators, Novac7 and Liac, for intraoperative radiation therapy through Monte Carlo simulation.

    Science.gov (United States)

    Righi, Sergio; Karaj, Evis; Felici, Giuseppe; Di Martino, Fabio

    2013-01-07

    The Novac7 and Liac are linear accelerators (linacs) dedicated to intraoperative radiation therapy (IORT), which produce high energy, very high dose-per-pulse electron beams. The characteristics of the accelerators heads of the Novac7 and Liac are different compared to conventional electron accelerators. The aim of this work was to investigate the specific characteristics of the Novac7 and Liac electron beams using the Monte Carlo method. The Monte Carlo code BEAMnrc has been employed to model the head and simulate the electron beams. The Monte Carlo simulation was preliminarily validated by comparing the simulated dose distributions with those measured by means of EBT radiochromic film. Then, the energy spectra, mean energy profiles, fluence profiles, photon contamination, and angular distributions were obtained from the Monte Carlo simulation. The Spencer-Attix water-to-air mass restricted collision stopping power ratios (sw,air) were also calculated. Moreover, the modifications of the percentage depth dose in water (backscatter effect) due to the presence of an attenuator plate composed of a sandwich of a 2 mm aluminum foil and a 4 mm lead foil, commonly used for breast treatments, were evaluated. The calculated sw,air values are in agreement with those tabulated in the IAEA TRS-398 dosimetric code of practice within 0.2% and 0.4% at zref (reference depth in water) for the Novac7 and Liac, respectively. These differences are negligible for practical dosimetry. The attenuator plate is sufficient to completely absorb the electron beam for each energy of the Novac7 and Liac; moreover, the shape of the dose distribution in water strongly changes with the introduction of the attenuator plate. This variation depends on the energy of the beam, and it can give rise to an increase in the maximum dose in the range of 3%-9%.

  15. Cosmogenic nuclide evidence on ages, sizes and orbits of meteorites

    Energy Technology Data Exchange (ETDEWEB)

    Alexeev, V.A.; Ustinova, G.K. [AN SSSR, Moscow (Russian Federation). Inst. Geokhimii i Analiticheskoj Khimii

    1995-12-01

    Meteorites, being the most ancient objects in the solar system, retain evidence of many events and processes which have played, perhaps, a crucial role in its formation. To derive and interpret correctly the available information, the history and evolution of the meteorites themselves must be studied thoroughly. Due to radiogenic and cosmogenic nuclides the chronology of meteorites can be retraced from the moment of solidification to their fall to Earth. A consideration of the properties and features of meteorites with different radiogenic and cosmic-ray ages of exposure makes it possible to locate key events in their evolution on a long term scale. Peculiarities in the formation mechanism of H- and L-chondrites have emerged. (author).

  16. Production yield of produced radioisotopes from 100 MeV proton beam on lead target for shielding analysis of large accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Oranj, Leila Mokhtari; Oh, Joo Hee; Jung, Nam Suk; Bae, O Ryun; Lee, Hee Seock [Div. of Advanced Nuclear Engineering, POSTECH, Pohang (Korea, Republic of)

    2014-11-15

    In this work, the production yield of major shielding material, a lead, was investigated using 100 MeV protons of KOMAC accelerator facility. For the analysis of the experimental data, the activity has been calculated using the FLUKA Monte Carlo code and analytical methods. The cross section data and the stopping power in the irradiated assembly were calculated by TALYS and SRIM codes in the analytical method, respectively. Consequently, the experimental production yield of produced radioisotopes was compared with the data that are based on Monte Carlo calculations and analytical studies. In this research, the {sup nat}Pb(p, x) reaction was studied using experimental measurements, Monte Carlo simulations and analytical methods. Rereading to the experimental measurements, we demonstrate that both Monte Carlo simulation and analytical methods could be useful tools for the estimation of production yield of this reaction.

  17. High-sensitivity AMS for heavy nuclides at the Munich Tandem accelerator

    CERN Document Server

    Knie, K; Korschinek, G; Rugel, G; Rühm, W; Wallner, C

    2000-01-01

    During the last years we have aimed at utilizing the high energy achievable at the Munich MP Tandem (TV=14 MV) for maximum sensitivity. One of our interests is the measurements of radionuclides around A=60 ( sup 5 sup 3 Mn, sup 6 sup 0 Fe, sup 6 sup 3 Ni) because of their high scientific potentials. However, in this mass region there are usually strong limitations in sensitivity due to a large isobaric background. Its suppression is performed by means of a gas-filled magnet and a multi DELTA E ionization chamber. A Wien filter and a time-of-flight path allow a further suppression of (non-isobaric) background. The optimization of the setup as a whole yielded detection limits of sup 5 sup 3 Mn/Mn approx 2x10 sup - sup 1 sup 4 sup 6 sup 3 Ni/Ni approx 2x10 sup - sup 1 sup 4 and sup 6 sup 0 Fe/Fe approx 2x10 sup - sup 1 sup 6 , which presently cannot be achieved by any other detection method. The overall efficiency (including ion source) is typically 10 sup - sup 5 -10 sup - sup 4. The gas-filled magnet allows an...

  18. Nuclide identification algorithm based on K-L transform and neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Chen Liang [Key Laboratory of Particle and Radiation Imaging (Tsinghua University), Department of Engineering Physics, Tsinghua University, Ministry of Education (China)], E-mail: cliang00@mails.tsinghua.edu.cn; Wei Yixiang [Key Laboratory of Particle and Radiation Imaging (Tsinghua University), Department of Engineering Physics, Tsinghua University, Ministry of Education (China)

    2009-01-11

    Traditional spectrum analysis algorithm based on peak search is hard to deal with complex overlapped peaks, especially in bad resolution and high background conditions. This paper described a new nuclide identification method based on the Karhunen-Loeve transform (K-L transform) and artificial neural networks. By the K-L transform and feature extraction, the nuclide gamma spectrum was compacted. The K-L transform coefficients were used as the neural network's input. The linear associative memory and ADALINE were discussed. Lots of experiments and tests showed that the method was credible and practical, especially suitable for fast nuclide identification.

  19. Nuclide identification algorithm based on K-L transform and neural networks

    Science.gov (United States)

    Chen, Liang; Wei, Yi-Xiang

    2009-01-01

    Traditional spectrum analysis algorithm based on peak search is hard to deal with complex overlapped peaks, especially in bad resolution and high background conditions. This paper described a new nuclide identification method based on the Karhunen-Loeve transform (K-L transform) and artificial neural networks. By the K-L transform and feature extraction, the nuclide gamma spectrum was compacted. The K-L transform coefficients were used as the neural network's input. The linear associative memory and ADALINE were discussed. Lots of experiments and tests showed that the method was credible and practical, especially suitable for fast nuclide identification.

  20. Detection of landscape transience using cosmogenic nuclides and topography

    Science.gov (United States)

    Mudd, S. M.

    2015-12-01

    Upland landscapes are frequently perturbed by changing tectonics and climate, which can lead to temporally and spatially varying erosion rates. Hillslopes and channels respond to these changes with different rates, and the dissonance between hillslope and channel response times can be exploited to gain information about the nature and timing of landscape transience. I explore the limits to which differences between channel and hillslope processes can be used to detect transience. Slowing channel erosion rates are difficult to detect, whereas increased erosion rates can be detected if erosion rates more than double. Signals of transient erosion driven by upslope propagation of channel incision can persist for thousands to tens of thousands of years; the time perturbations can be detected is proportional to the square of the hillslope length and the inverse of the hillslope sediment transport coefficient. Climate driven ("top down") and tectonic driven ("bottom up") have different responses to transient perturbation, and lead to different sediment flux responses that are reflected in basinwide cosmogenic nuclide concentrations. Climate driven perturbations are mirrored in cosmogenic concentrations leaving basins whereas tectonic perturbations tend to be averaged when estimated from basinwide cosmogenics.

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

    Science.gov (United States)

    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.

  2. Silencing SlELP2L, a tomato Elongator complex protein 2-like gene, inhibits leaf growth, accelerates leaf, sepal senescence, and produces dark-green fruit.

    Science.gov (United States)

    Zhu, Mingku; Li, Yali; Chen, Guoping; Ren, Lijun; Xie, Qiaoli; Zhao, Zhiping; Hu, Zongli

    2015-01-09

    The multi-subunit complex Elongator interacts with elongating RNA polymerase II (RNAPII) and is thought to facilitate transcription through histone acetylation. Elongator is highly conserved in eukaryotes, yet has multiple kingdom-specific functions in diverse organisms. Recent genetic studies performed in Arabidopsis have demonstrated that Elongator functions in plant growth and development, and in response to biotic and abiotic stress. However, little is known about its roles in other plant species. Here, we study the function of an Elongator complex protein 2-like gene in tomato, here designated as SlELP2L, through RNAi-mediated gene silencing. Silencing SlELP2L in tomato inhibits leaf growth, accelerates leaf and sepal senescence, and produces dark-green fruit with reduced GA and IAA contents in leaves, and increased chlorophyll accumulation in pericarps. Gene expression analysis indicated that SlELP2L-silenced plants had reduced transcript levels of ethylene- and ripening-related genes during fruit ripening with slightly decreased carotenoid content in fruits, while the expression of DNA methyltransferase genes was up-regulated, indicating that SlELP2L may modulate DNA methylation in tomato. Besides, silencing SlELP2L increases ABA sensitivity in inhibiting seedling growth. These results suggest that SlELP2L plays important roles in regulating plant growth and development, as well as in response to ABA in tomato.

  3. High efficient ultrahigh acceleration of plasma blocks by PW-ps laser pulses for producing fusion flames in DT and HB11 of solid state density

    Science.gov (United States)

    Moustaizis, S.; Lalousis, P.; Hora, H.; Miley, G. H.

    2016-03-01

    Ultrahigh acceleration of plasma blocks in the range of 1020 cm/s2 has been confirmed experimentally after this was long predicted as a non-thermal direct conversion of optical energy into plasma motion due to dominating nonlinear (ponderomotive) forces [1]. The use of laser pulses of more than PW power and ps or shorter duration can ignite a nuclear fusion flame in solid density deuterium tritium because the necessary energy flux of >108J/cm2 according to the theory of Chu [2] is available [3]. For the studies of the necessary velocities of the generated fusion flames above 1000 km/s the detailed processes can be analyzed by using the advanced genuine two-fluid hydrodynamic model [4] where it was surprising that the ignition of the fusion flame by the picosecond interaction needs a comparably long development in the nanosecond range before the thermal processes result in shock fronts similar to the Rakine-Hugoniot theory. For the evaluation of power generation the problem of lateral energy losses was studied by using very high pulsed magnetic fields. The recently produced 10 Kilotesla magnetic fields [5] are very promising for solutions.

  4. Gradient of γ rays and β particles irradiation’s energy produced by accelerator and its use in radiotherapy of cancer diseases

    Energy Technology Data Exchange (ETDEWEB)

    Kastrati, Labinot, E-mail: labinotkastrati82@gmail.com; Nafezi, Gazmend, E-mail: gazmend-nafezi@hotmail.com [Department of Physics, Faculty of Mathematical and Natural Sciences, University of Prishtina “HasanPrishtina”, Prishtina, Kosovo (Country Unknown); Shehi, Gëzim, E-mail: gezimshehi@yahoo.com [Department of Physics, Faculty of Mathematical and Natural Sciences, University of Tirana, Tirana (Albania)

    2016-03-25

    The Ionising irradiations used mostly in the treatment of tumoral diseases are: X, γ, β and e irradiations. The discussion will be about radiations, produced in accelerators, with photon energy 6 MV and 15 MV and electron energy from 5 MeV to 15 MeV. Due to the differences between γ and β radiations, their absorbtion in living tissues will be different. It is important to know, the absorption performance before and after the electronic equilibrium. For these purposes, we’ve use the function of dose gradient, for irradiations γ and β. It represents the velocity of dose change as a function of depth in tissue. From skin to maximum dose value, the increase of G-function is more accentuated for γ-rays than for β-particles, while after that the G-function decreasing is less sharp for γ-rays, while for β-particles, it is almost promptly. This fact allow us to use in radiotherapy, not only γ-rays but β-particles, too. The lasts, represents, a much more efficient tool, especially in terms of radiation protection, of health adjacent tissues and organs. Finally, we’ll to discus, about the advantages in terms of radiation protection of both, γ-rays and β-particles used in radiotherapy.

  5. Recommended Partition Coefficient (Kd) Values for Nuclide Partitioning in the Presence of Cellulose Degradation Products

    Energy Technology Data Exchange (ETDEWEB)

    Serkiz, S.M.

    2001-02-23

    This report documents the data analysis of the results of the described laboratory studies in order to recommend Kd values for use in Performance Assessment modeling of nuclide transport in the presence of CDP.

  6. Phase II Nuclide Partition Laboratory Study Influence of Cellulose Degradation Products on the Transport of Nuclides from SRS Shallow Land Burial Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Serkiz, S.M.

    1999-10-04

    Degradation products of cellulosic materials (e.g., paper and wood products) can significantly influence the subsurface transport of metals and radionuclides. Codisposal of radionuclides with cellulosic materials in the E-Area slit trenches at the Savannah River Site (SRS) is, therefore, expected to influence nuclide fate and transport in the subsurface. Due to the complexities of these systems and the scarcity of site-specific data, the effects of cellulose waste loading and its subsequent influence on nuclide transport are not well established.

  7. Characterization methodology for Difficult To Measure nuclides in the Type B rad waste from the ITER

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Youngyong; Hong, Kwonpyo; Oh, Wanho; Kang, Munja; Na, Byungchan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-10-15

    In general, it is not possible to directly detect beta rays from the rad waste in the field measurement due to their extremely low penetration through the materials. Only lab-scale measurements with proper shield and detecting system are available for the nondestructive assay. However, the disposal sites in many countries require the determination of inventories of the difficult to-measure (DTM) nuclides in the waste before their acceptance for disposal. Many sites that generate rad wastes thus are adapting the indirect method to characterize the DTM nuclides in the rad waste to be disposed. The rad waste from the operation of an international thermonuclear experimental reactor (ITER) will be sent to the hot cell building (HCB) after packing it to the basket and they are then treated into the disposal form as well as characterized through the nondestructive assay. The rad waste properties from the ITER are that high density material such as a steel, a copper, and a tungsten accounts for the main substance and many nuclides due to the neutron irradiation including the DTM nuclides exists in that waste. Therefore, the ITER is also facing with the problem for the characterization of DTM nuclides. The scaling factor for the radiological relationship between the gamma and the beta nuclides is one of the indirect measurements to characterize the DTM nuclides in the waste. The methodology of the scaling factor to apply this method to the characterization the Type B rad waste from the ITER are presented in this paper. There are several types of the in-vessel components (IVCs) in a Tokamak which will be activated by neutron and they will be divided into different types of the rad waste such as the divertor cassette, blanket module, and port plugs. In this paper, the characterization of DTM nuclides will be focused on the rad waste from a blanket module out of IVCs.

  8. Nuclear medical imaging using β+γ coincidences from 44Sc radio-nuclide with liquid xenon as detection medium

    Science.gov (United States)

    Grignon, C.; Barbet, J.; Bardiès, M.; Carlier, T.; Chatal, J. F.; Couturier, O.; Cussonneau, J. P.; Faivre, A.; Ferrer, L.; Girault, S.; Haruyama, T.; Le Ray, P.; Luquin, L.; Lupone, S.; Métivier, V.; Morteau, E.; Servagent, N.; Thers, D.

    2007-02-01

    We report on a new nuclear medical imaging technique based on the measurement of the emitter location in the three dimensions with a few mm spatial resolution using β+γ emitters. Such measurement could be realized thanks to a new kind of radio-nuclides which emit a γ-ray quasi-simultaneously with the β+ decay. The most interesting radio-nuclide candidate, namely 44Sc, will be potentially produced at the Nantes cyclotron ARRONAX. The principle is to reconstruct the intersection of the classical line of response (obtained with a standard PET camera) with the direction cone defined by the third γ-ray. The emission angle measurement of this additional γ-ray involves the use of a Compton telescope for which a new generation of camera based on a liquid xenon (LXe) time projection chamber is considered. GEANT3 simulations of a large acceptance LXe Compton telescope combined with a commercial micro-PET (LSO crystals) have been performed and the obtained results will be presented. They demonstrate that a good image can be obtained from the accumulation of each three-dimensional measured position. A spatial resolution of 2.3 mm has been reached with an injected activity of 0.5 MBq for a 44Sc point source emitter.

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

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

    Directory of Open Access Journals (Sweden)

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

    Science.gov (United States)

    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

  12. Timing of European fluvial terrace formation and incision rates constrained by cosmogenic nuclide dating

    Science.gov (United States)

    Schaller, Mirjam; Ehlers, Todd A.; Stor, Tomas; Torrent, Jose; Lobato, Leonardo; Christl, Marcus; Vockenhuber, Christof

    2016-10-01

    Age constraints of late Cenozoic fluvial terraces are important for addressing surface process questions related to the incision rates of rivers, or tectonic and climate controls on denudation and sedimentation. Unfortunately, absolute age constraints of fluvial terraces are not always possible, and many previous studies have often dated terraces with relative age constraints that do not allow for robust interpretations of incision rates and timing of terrace formation. However, in situ-produced cosmogenic nuclides allow absolute age determination, and hence incision rates, of fluvial deposits back to 5 Ma. Here we present, cosmogenic depth profile dating and isochron burial dating of four different river systems in Europe spanning 12° of latitude. We do this to determine river incision rates and spatial variations in the timing of terrace formation. Isochron burial age constraints of four selected terraces from the Vltava river (Czech Republic) range between 1.00 ± 0.21 to 1.99 ± 0.45Ma. An isochron burial age derived for the Allier river (Central France) is 2.00 ± 0.17Ma. Five terrace levels from the Esla river (NW Spain) were dated between 0.08 + 0.04 / - 0.01Ma and 0.59 + 0.13 / - 0.20Ma with depth profile dating. The latter age agrees with an isochron burial age of 0.52 ± 0.20Ma. Two terrace levels from the Guadalquivir river (SW Spain) were dated by depth profile dating to 0.09 + 0.03 / - 0.02Ma and 0.09 + 0.04 / - 0.03Ma. The one terrace level from the Guadalquivir river dated by isochron burial dating resulted in an age of 1.79 ± 0.18Ma. Results indicate that the cosmogenic nuclide-based ages are generally older than ages derived from previous relative age constraints leading to a factor 2-3 lower incision rates than previous work. Furthermore, the timing of terrace formation over this latitudinal range is somewhat obscured by uncertainties associated with dating older terraces and not clearly synchronous with global climate variations.

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

    CERN Document Server

    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...

  14. A multi-layered active target for the study of neutron-unbound nuclides at NSCL

    Science.gov (United States)

    Freeman, Jessica; Gueye, Paul; Redpath, Thomas; MoNA Collaboration

    2017-01-01

    The characteristics of neutron-unbound nuclides were investigated using a multi-layered Si/Be active target designed for use with the MoNA/LISA setup at the National Superconducting Cyclotron (NSCL). The setup consists of the MoNA/LISA arrays (for neutron detection) and a superconducting sweeper magnet (for charged separation) to identify products following the decay of neutron unbound states. The segmented target consisted of three 700 mg/cm2 beryllium targets and four 0.14 mm thick 62x62 mm2 silicon detectors. As a commissioning experiment for the target the decay of two-neutron unbound 26O populated in a one-proton removal reaction from a radioactive 27F beam was performed. The 27F secondary radioactive beam from the NSCL's Coupled Cyclotron Facility was produced from the fragmentation of a 140 MeV/u 48Ca beam incident on a thick beryllium target and then cleanly selected by the A1900 fragment separator. The energy loss and position spectra of the incoming beam and reaction products were used to calibrate the Silicon detectors to within 1.5% in both energy and position. A dedicated Geant4 model of the target was developed to simulate the energy loss within the target. A description of the experimental setup, simulation work, and energy and position calibration will be presented. DoE/NNSA - DE-NA0000979.

  15. Accelerator mass spectrometry.

    Science.gov (United States)

    Hellborg, Ragnar; Skog, Göran

    2008-01-01

    In this overview the technique of accelerator mass spectrometry (AMS) and its use are described. AMS is a highly sensitive method of counting atoms. It is used to detect very low concentrations of natural isotopic abundances (typically in the range between 10(-12) and 10(-16)) of both radionuclides and stable nuclides. The main advantages of AMS compared to conventional radiometric methods are the use of smaller samples (mg and even sub-mg size) and shorter measuring times (less than 1 hr). The equipment used for AMS is almost exclusively based on the electrostatic tandem accelerator, although some of the newest systems are based on a slightly different principle. Dedicated accelerators as well as older "nuclear physics machines" can be found in the 80 or so AMS laboratories in existence today. The most widely used isotope studied with AMS is 14C. Besides radiocarbon dating this isotope is used in climate studies, biomedicine applications and many other fields. More than 100,000 14C samples are measured per year. Other isotopes studied include 10Be, 26Al, 36Cl, 41Ca, 59Ni, 129I, U, and Pu. Although these measurements are important, the number of samples of these other isotopes measured each year is estimated to be less than 10% of the number of 14C samples.

  16. 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?

    Data.gov (United States)

    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...

  17. Isotopic hysteresis in detrital cosmogenic nuclide-derived denudation rate studies (Invited)

    Science.gov (United States)

    Willenbring, J.; Gasparini, N. M.; Crosby, B. T.; Brocard, G. Y.; Belmont, P.

    2013-12-01

    In equilibrium landscapes, the concentration of beryllium-10 (10Be) from fluvially transported material is expected to quantitatively reflect basin-wide denudation rates. No isotopic time-dependent path is considered because the concentrations reflect an integrated measurement over a sufficiently long period of time to be static. However, the responses of landscapes to changing conditions are often addressed with cosmogenic nuclides in transient landscapes to identify and quantify the primary topographic and climatic controls on erosion. With the advent of techniques that allow event-scale measurement of cosmogenic nuclide concentrations over the course of a flood wave, in the case of meteoric 10Be, or over the course of an uplift wave, in the case of in situ-produced 10Be, we can now evaluate the how the isotope changes and what the 'mean' denudation rate from a single time means. Meteoric 10Be concentrations can be extracted from, and measured in, milligram-sized sediment samples. This attribute enables us to measure suspended sediment through a hydrograph. Here, we give a case study in an agricultural setting. The meteoric 10Be concentration in river sediment changes with the source areas of the fine sediment and fluxes of material supplied to the stream. The average concentration from the couplet of the rising and falling limbs of the hydrograph can differ from the concentration of the sediment that is preserved in depo-centers. Using traditional in situ-produced 10Be, the timescale of the perturbation must be sufficiently long to change the isotopic composition of the bedload, but also for the landscape to respond to the forcing factor. Here, we give an example from a transient landscape where a wave of uplift moves through the basin and a wave of incision follows in its wake. In this setting, 10Be from detrital quartz is derived from both the incising, adjusting lowland and the unadjusted, relict upland, and the integrated 10Be concentrations still provide a

  18. Apparatus for nuclear transmutation and power production using an intense accelerator-generated thermal neutron flux

    Science.gov (United States)

    Bowman, Charles D.

    1992-01-01

    Apparatus for nuclear transmutation and power production using an intense accelerator-generated thermal neutron flux. High thermal neutron fluxes generated from the action of a high power proton accelerator on a spallation target allows the efficient burn-up of higher actinide nuclear waste by a two-step process. Additionally, rapid burn-up of fission product waste for nuclides having small thermal neutron cross sections, and the practicality of small material inventories while achieving significant throughput derive from employment of such high fluxes. Several nuclear technology problems are addressed including 1. nuclear energy production without a waste stream requiring storage on a geological timescale, 2. the burn-up of defense and commercial nuclear waste, and 3. the production of defense nuclear material. The apparatus includes an accelerator, a target for neutron production surrounded by a blanket region for transmutation, a turbine for electric power production, and a chemical processing facility. In all applications, the accelerator power may be generated internally from fission and the waste produced thereby is transmuted internally so that waste management might not be required beyond the human lifespan.

  19. A model for GCR-particle fluxes in stony meteorites and production rates of cosmogenic nuclides

    Science.gov (United States)

    Reedy, R. C.

    1985-02-01

    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 and energetic GCR particles occur near the centers of meteorites with radii of 40 to 70 g/cm (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 measurments 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.

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

    CERN Multimedia

    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...

  1. Industrial applications of electron accelerators

    CERN Document Server

    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.

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

    Science.gov (United States)

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

    2016-08-01

    Ultra-short proton pulses originating from laser-plasma accelerators can provide instantaneous dose rates at least 107-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 DNA damaging potential as conventional proton beams, while inducing less immediate nitroxidative stress, which probably entails a distinct therapeutic potential.

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

    CERN Document Server

    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...

  4. Some nuclear chemical aspects of medical generator nuclide production at the Los Alamos hot cell facility

    CERN Document Server

    Fassbender, M; Heaton, R C; Jamriska, D J; Kitten, J J; Nortier, F M; Peterson, E J; Phillips, D R; Pitt, L R; Salazar, L L; Valdez, F O; 10.1524/ract.92.4.237.35596

    2004-01-01

    Generator nuclides constitute a convenient tool for applications in nuclear medicine. In this paper, some radiochemical aspects of generator nuclide parents regularly processed at Los Alamos are introduced. The bulk production of the parent nuclides /sup 68/Ge, /sup 82/Sr, /sup 109/Cd and /sup 88/Zr using charged particle beams is discussed. Production nuclear reactions for these radioisotopes, and chemical separation procedures are presented. Experimental processing yields correspond to 80%-98% of the theoretical thick target yield. Reaction cross sections are modeled using the code ALICE-IPPE; it is observed that the model largely disagrees with experimental values for the nuclear processes treated. Radionuclide production batches are prepared 1-6 times yearly for sales. Batch activities range from 40MBq to 75 GBq.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. Cosmogenic nuclides in the Martian meteorites ALHA 77005, Lafayette and Zagami

    Energy Technology Data Exchange (ETDEWEB)

    Bastian, T.; Herpers, U. [Koeln Univ. (Germany). Abt. Nuklearchemie; Kubik, P.W. [PSI c/o Institute of Particle Physics, HPK, ETH Hoenggerberg, Zuerich (Switzerland); Knie, K. [Technische Univ. Muenchen, Garching (Germany). Physik Dept.; Ott, U. [MPI fuer Chemie, Mainz (Germany); Michel, R. [Hannover Univ. (Germany). Zentrum fuer Strahlenschutz und Radiooekologie

    2004-07-01

    The availability of effective physical models for the calculation of production rates of cosmogenic nuclides in meteorites allows an exact analysis of the irradiation history of meteorites. The relative errors of calculated production rates lay below 10%. At present, concentration ratios of cosmogenic nuclides can be calculated even with errors of less than 3%. The model used in this work calculates the part of the nuclide production which comes from the interaction of the galactic cosmic radiation with the meteoroid matter. For this reason any other additional production is easily identifiable. Such overproductions are basically caused by two phenomena: complex irradiation histories and the solar cosmic radiation (SCR-effect). In this work the SCR-effect for the cosmogenic radionuclides {sup 10}Be, {sup 26}Al and {sup 53}Mn is demonstrated. (orig.)

  7. Waste zone labelling at the Lure accelerator facility; Etude de zonage dechets de l'accelerateur Lure

    Energy Technology Data Exchange (ETDEWEB)

    Cometto, M.; Damoy, F.; Giacri-Mauborgne, M.L.; Ridikas, D.; Thomas, W

    2005-07-01

    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: Na{sup 22}, Cl{sup 36}, Mn{sup 54}, Nb{sup 92}, Ba{sup 133}, Co{sup 57} and Co{sup 60}. The main neutron reaction generate the following nuclides: H{sup 3}, C{sup 14}, Cl{sup 36}, K{sup 40}, Co{sup 60}, Ni{sup 63}, Zn{sup 65}, Se{sup 79}, Zr{sup 93}, Ag{sup 108}, Ag{sup 110}, Ba{sup 133}, Cs{sup 134}, Eu{sup 152}, Eu{sup 154}, Fe{sup 55}, Ca{sup 41}, Na{sup 22}, Mn{sup 54}, Cs{sup 137}, Nb{sup 92} and Ti{sup 204}. 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 Ca{sup 41} and Ni{sup 63}. 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 Co{sup 60}, Cs{sup 134}, Eu{sup 152} and Eu{sup 154}. 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.)

  8. 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

    CERN Document Server

    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...

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

    CERN Document Server

    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.

  10. On a solar origin for the cosmogenic nuclide event of 775 A.D

    Energy Technology Data Exchange (ETDEWEB)

    Cliver, E. W. [Space Vehicles Directorate, Air Force Research Laboratory, Sunspot, NM 88349 (United States); Tylka, A. J. [Code 672, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Dietrich, W. F. [Praxis, Inc., Alexandria, VA 22303 (United States); Ling, A. G. [Atmospheric Environmental Research, 3550 Aberdeen Ave., Kirtland AFB, NM 87117 (United States)

    2014-01-20

    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 >1 GV spectrum ∼45 times stronger than that of the intense high-energy SPE of 1956 February 23. This implies a >30 MeV proton fluence (F {sub 30}) of ∼8 × 10{sup 10} proton cm{sup –2}, ∼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 >30 MeV solar proton events. The best guess value for the soft X-ray classification (total energy) of an associated flare is ∼X230 (∼9 × 10{sup 33} erg). For comparison, the flares on 2003 November 4 and 1859 September 1 had observed/inferred values of ∼X35 (∼10{sup 33} erg) and ∼X45 (∼2 × 10{sup 33} erg), respectively. The estimated size of the source active region for a ∼10{sup 34} erg flare is ∼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 ∼1945-1995 interval, the most active of the last ∼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.

  11. Numeric determination and validation of neutron induced radioactive nuclide inventories for decommissioning and dismantling of light water reactors; Rechnerische Bestimmung und Validierung von Aktivierungsaktivitaeten fuer die Rueckbau- und Entsorgungsplanung von Leichtwasserreaktoren

    Energy Technology Data Exchange (ETDEWEB)

    Phlippen, Peter W.; Schloemer, Luc; Vallentin, Roger [WTI Wissenschaftlich-Technische Ingenieurberatung GmbH, Juelich (Germany); Lukas, Bernard [EnBW Kernkraft GmbH Kernkraftwerk Philippsburg (Germany); Palm, Stefan [EnBW Kernkraft GmbH Kernkraftwerk Neckarwestheim (Germany)

    2017-02-15

    The deconstruction of nuclear power plants requires project planning and budgeting both during the project and in advance, as well as the secured provision of financial and human resources. When a facility is free from irradiated fuel, the reactor pressure vessel with the nuclear components as well as the biological shield determine the activity inventory of the facility, which almost exclusively consists of activated radionuclides located in the respective structures. Knowledge of the activity distribution and nuclide vectors of the involved components is of vital importance for deconstruction planning. In this context, the development of a computation procedure is described coupling the Monte Carlo method for the determination of neutron flux densities with a procedure to perform activation calculations for the determination of nuclide vectors. For this purpose, detailed knowledge of the material composition, particularly the trace-element concentrations of nitrogen and cobalt in steel and additionally of europium and caesium in concrete structures, considerably impacts the accuracy of the calculated activities. Extensive validation using data collected from various reactor facilities, such as nuclide activities, neutron flux densities, and neutron and gamma dose rates, demonstrates the reliability of the computed nuclide distributions showing ratios of computed over measured values of typically between 0.9 and 3. The practicality of the developed method as well as the convenient use of the results have already been demonstrated analysing several German BWR and PWR facilities and developing packaging strategies based on the produced results.

  12. First results using a new technology for measuring masses of very short-lived nuclides with very high accuracy the MISTRAL program at ISOLDE

    CERN Document Server

    Monsanglant, C; Audi, G; Bollen, G; Borcea, C; Conreur, G; Cousin, R; Doubre, H; Duma, M; Jacotin, M; Henry, S; Képinski, J F; Kluge, H J; Lebée, G; Le Scornet, G; Lunney, S; De Saint-Simon, M; Scheidenberger, C; Thibault, C

    1999-01-01

    MISTRAL is an experimental program to measure masses of very short- lived nuclides (T$_{1/2}$ down to a few ms), with a very high accuracy (a few 10$^{-7}$). There were three data taking periods with radioactive beams and 22 masses of isotopes of Ne, Na*, Mg, Al*, K, Ca, and Ti were measured. The systematic errors are now under control at the level of 8$\\TIMES10^{-7}$, allowing to come close to the expected accuracy. Even for the very weakly produced $^{30}$Na (1 ion at the detector per proton burst), the final accuracy is 7$\\TIMES10^{-7}$. (15 refs).

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

    Energy Technology Data Exchange (ETDEWEB)

    Unger, L.M.; Trubey, D.K.

    1982-05-01

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Unger, L.M.; Trubey, D.K.

    1981-09-01

    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.

  15. Nuclide separation modeling through reverse osmosis membranes in radioactive liquid waste

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung Sik [KEPCO Engineering and Construction, Gimcheon (Korea, Republic of)

    2015-12-15

    The aim of this work is to investigate the transport mechanism of radioactive nuclides through the reverse osmosis (RO) membrane and to estimate its effectiveness for nuclide separation from radioactive liquid waste. An analytical model is developed to simulate the RO separation, and a series of experiments are set up to confirm its estimated separation behavior. The model is based on the extended Nernst-Plank equation, which handles the convective flux, diffusive flux, and electromigration flux under electroneutrality and zero electric current conditions. The distribution coefficient which arises due to ion interactions with the membrane material and the electric potential jump at the membrane interface are included as boundary conditions in solving the equation. A high Peclet approximation is adopted to simplify the calculation, but the effect of concentration polarization is included for a more accurate prediction of separation. Cobalt and cesium are specifically selected for the experiments in order to check the separation mechanism from liquid waste composed of various radioactive nuclides and nonradioactive substances, and the results are compared with the estimated cobalt and cesium rejections of the RO membrane using the model. Experimental and calculated results are shown to be in excellent agreement. The proposed model will be very useful for the prediction of separation behavior of various radioactive nuclides by the RO membrane.

  16. Nuclide separation modeling through reverse osmosis membranes in radioactive liquid waste

    Directory of Open Access Journals (Sweden)

    Byung-Sik Lee

    2015-12-01

    Full Text Available The aim of this work is to investigate the transport mechanism of radioactive nuclides through the reverse osmosis (RO membrane and to estimate its effectiveness for nuclide separation from radioactive liquid waste. An analytical model is developed to simulate the RO separation, and a series of experiments are set up to confirm its estimated separation behavior. The model is based on the extended Nernst–Plank equation, which handles the convective flux, diffusive flux, and electromigration flux under electroneutrality and zero electric current conditions. The distribution coefficient which arises due to ion interactions with the membrane material and the electric potential jump at the membrane interface are included as boundary conditions in solving the equation. A high Peclet approximation is adopted to simplify the calculation, but the effect of concentration polarization is included for a more accurate prediction of separation. Cobalt and cesium are specifically selected for the experiments in order to check the separation mechanism from liquid waste composed of various radioactive nuclides and nonradioactive substances, and the results are compared with the estimated cobalt and cesium rejections of the RO membrane using the model. Experimental and calculated results are shown to be in excellent agreement. The proposed model will be very useful for the prediction of separation behavior of various radioactive nuclides by the RO membrane.

  17. Neutron Halo and Nuclear Shell Structure in New Nuclide 31Ne

    Institute of Scientific and Technical Information of China (English)

    REN ZhongZhou; CHEN BaoQiu; MA ZhongYu; XU GongOu

    2001-01-01

    The ground state properties of new nuclide 31Ne are investigated within the framework of the densitydependent relativistic mean-field theory. One-neutron halo in 31Ne is predicted. Calculations also show that the ground state of31Ne is (3/2)- and it can be used for the testing of the nuclear shell structure near the neutron-drip line.``

  18. Development of Advanced Nuclide Separation and Recovery Methods using Ion-Exchanhge Techniques in Nuclear Backend

    Science.gov (United States)

    Miura, Hitoshi

    The development of compact separation and recovery methods using selective ion-exchange techniques is very important for the reprocessing and high-level liquid wastes (HLLWs) treatment in the nuclear backend field. The selective nuclide separation techniques are effective for the volume reduction of wastes and the utilization of valuable nuclides, and expected for the construction of advanced nuclear fuel cycle system and the rationalization of waste treatment. In order to accomplish the selective nuclide separation, the design and synthesis of novel adsorbents are essential for the development of compact and precise separation processes. The present paper deals with the preparation of highly functional and selective hybrid microcapsules enclosing nano-adsorbents in the alginate gel polymer matrices by sol-gel methods, their characterization and the clarification of selective adsorption properties by batch and column methods. The selective separation of Cs, Pd and Re in real HLLW was further accomplished by using novel microcapsules, and an advanced nuclide separation system was proposed by the combination of selective processes using microcapsules.

  19. Bayesian estimation of a source term of radiation release with approximately known nuclide ratios

    Science.gov (United States)

    Tichý, Ondřej; Šmídl, Václav; Hofman, Radek

    2016-04-01

    We are concerned with estimation of a source term in case of an accidental release from a known location, e.g. a power plant. Usually, the source term of an accidental release of radiation comprises of a mixture of nuclide. The gamma dose rate measurements do not provide a direct information on the source term composition. However, physical properties of respective nuclide (deposition properties, decay half-life) can be used when uncertain information on nuclide ratios is available, e.g. from known reactor inventory. The proposed method is based on linear inverse model where the observation vector y arise as a linear combination y = Mx of a source-receptor-sensitivity (SRS) matrix M and the source term x. The task is to estimate the unknown source term x. The problem is ill-conditioned and further regularization is needed to obtain a reasonable solution. In this contribution, we assume that nuclide ratios of the release is known with some degree of uncertainty. This knowledge is used to form the prior covariance matrix of the source term x. Due to uncertainty in the ratios the diagonal elements of the covariance matrix are considered to be unknown. Positivity of the source term estimate is guaranteed by using multivariate truncated Gaussian distribution. Following Bayesian approach, we estimate all parameters of the model from the data so that y, M, and known ratios are the only inputs of the method. Since the inference of the model is intractable, we follow the Variational Bayes method yielding an iterative algorithm for estimation of all model parameters. Performance of the method is studied on simulated 6 hour power plant release where 3 nuclide are released and 2 nuclide ratios are approximately known. The comparison with method with unknown nuclide ratios will be given to prove the usefulness of the proposed approach. This research is supported by EEA/Norwegian Financial Mechanism under project MSMT-28477/2014 Source-Term Determination of Radionuclide Releases

  20. Methods of increasing the performance of radionuclide generators used in nuclear medicine: daughter nuclide build-up optimisation, elution-purification-concentration integration, and effective control of radionuclidic purity.

    Science.gov (United States)

    Le, Van So; Do, Zoe Phuc-Hien; Le, Minh Khoi; Le, Vicki; Le, Natalie Nha-Truc

    2014-06-10

    Methods of increasing the performance of radionuclide generators used in nuclear medicine radiotherapy and SPECT/PET imaging were developed and detailed for 99Mo/99mTc and 68Ge/68Ga radionuclide generators as the cases. Optimisation methods of the daughter nuclide build-up versus stand-by time and/or specific activity using mean progress functions were developed for increasing the performance of radionuclide generators. As a result of this optimisation, the separation of the daughter nuclide from its parent one should be performed at a defined optimal time to avoid the deterioration in specific activity of the daughter nuclide and wasting stand-by time of the generator, while the daughter nuclide yield is maintained to a reasonably high extent. A new characteristic parameter of the formation-decay kinetics of parent/daughter nuclide system was found and effectively used in the practice of the generator production and utilisation. A method of "early elution schedule" was also developed for increasing the daughter nuclide production yield and specific radioactivity, thus saving the cost of the generator and improving the quality of the daughter radionuclide solution. These newly developed optimisation methods in combination with an integrated elution-purification-concentration system of radionuclide generators recently developed is the most suitable way to operate the generator effectively on the basis of economic use and improvement of purposely suitable quality and specific activity of the produced daughter radionuclides. All these features benefit the economic use of the generator, the improved quality of labelling/scan, and the lowered cost of nuclear medicine procedure. Besides, a new method of quality control protocol set-up for post-delivery test of radionuclidic purity has been developed based on the relationship between gamma ray spectrometric detection limit, required limit of impure radionuclide activity and its measurement certainty with respect to

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

    Energy Technology Data Exchange (ETDEWEB)

    Thatcher, T; Madsen, S; Sudowe, R [University of Nevada, Las Vegas, Las Vegas, NV (United States); Meigooni, A Soleimani [University of Nevada, Las Vegas, Las Vegas, NV (United States); Comprehensive Cancer Center of Nevada, Las Vegas, Nevada (United States)

    2015-06-15

    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.

  2. Marginal accuracy of nickel chromium copings fabricated by conventional and accelerated casting procedures, produced with ringless and metal ring investment procedures: A comparative in vitro study

    Science.gov (United States)

    Alex, Deepa; Shetty, Y. Bharath; Miranda, Glynis Anita; Prabhu, M. Bharath; Karkera, Reshma

    2015-01-01

    Background: Conventional investing and casting techniques are time-consuming and usually requires 2–4 h for completion. Accelerated nonstandard, casting techniques have been reported to achieve similar quality results in significantly less time, namely, in 30–40 min. During casting, it is essential to achieve compensation for the shrinkage of solidifying alloy by investment expansion. The metal casting ring restricts the thermal expansion of investment because the thermal expansion of the ring is lesser than that of the investment. The use of casting ring was challenged with the introduction of the ringless technique. Materials and Methods: A total of 40 test samples of nickel chromium (Ni-Cr) cast copings were obtained from the patterns fabricated using inlay casting wax. The 20 wax patterns were invested using metal ring and 20 wax patterns were invested using the ringless investment system. Of both the groups, 10 samples underwent conventional casting, and the other 10 underwent accelerated casting. The patterns were casted using the induction casting technique. All the test samples of cast copings were evaluated for vertical marginal gaps at four points on the die employing a stereo optical microscope. Results: The vertical marginal discrepancy data obtained were tabulated. Mean and standard deviations were obtained. Vertical discrepancies were analyzed using analysis of variance and Tukey honestly significantly different. The data obtained were found to be very highly significant (P < 0.001). Mean vertical gap was the maximum for Group II (53.64 μm) followed by Group IV (47.62 μm), Group I (44.83 μm) and Group III (35.35 μm). Conclusion: The Ni-Cr cast copings fabricated with the conventional casting using ringless investment system showed significantly better marginal fit than that of cast copings fabricated from conventional and accelerated casting with metal ring investment and accelerated casting using ringless investment since those copings had

  3. Possible incorporation of petroleum-based carbons in biochemicals produced by bioprocess--biomass carbon ratio measured by accelerator mass spectrometry.

    Science.gov (United States)

    Kunioka, Masao

    2010-06-01

    The biomass carbon ratios of biochemicals related to biomass have been reviewed. Commercial products from biomass were explained. The biomass carbon ratios of biochemical compounds were measured by accelerator mass spectrometry (AMS) based on the (14)C concentration of carbons in the compounds. This measuring method uses the mechanism that biomass carbons include a very low level of (14)C and petroleum carbons do not include (14)C similar to the carbon dating measuring method. It was confirmed that there were some biochemicals synthesized from petroleum-based carbons. This AMS method has a high accuracy with a small standard deviation and can be applied to plastic products.

  4. Accelerators Beyond The Tevatron?

    Energy Technology Data Exchange (ETDEWEB)

    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?

  5. Leaky Fermi accelerators

    CERN Document Server

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  7. Particle-accelerator decommissioning

    Energy Technology Data Exchange (ETDEWEB)

    Opelka, J.H.; Mundis, R.L.; Marmer, G.J.; Peterson, J.M.; Siskind, B.; Kikta, M.J.

    1979-12-01

    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.

  8. TOF-Brho Mass Measurements of Very Exotic Nuclides for Astrophysical Calculations at the NSCL

    CERN Document Server

    Matos, M; Amthor, M; Aprahamian, A; Bazin, D; Becerril, A; Elliot, T; Galaviz, D; Gade, A; Gupta, S; Lorusso, G; Montes, F; Pereira, J; Portillo, M; Rogers, A M; Schatz, H; Shapira, D; Smith, E; Stolz, A; Wallace, M

    2008-01-01

    Atomic masses play a crucial role in many nuclear astrophysics calculations. The lack of experimental values for relevant exotic nuclides triggered a rapid development of new mass measurement devices around the world. The Time-of-Flight (TOF) mass measurements offer a complementary technique to the most precise one, Penning trap measurements, the latter being limited by the rate and half-lives of the ions of interest. The NSCL facility provides a well-suited infrastructure for TOF mass measurements of very exotic nuclei. At this facility, we have recently implemented a TOF-Brho technique and performed mass measurements of neutron-rich nuclides in the Fe region, important for r-process calculations and for calculations of processes occurring in the crust of accreting neutron stars.

  9. A systematization of the half-lives for proton emitter nuclides

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Martha M.N.; Duarte, Sergio B.; Medeiros, Emil de L.; Tavares, Odilon A.P. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)]. E-mails: nicke@cbpf.br; sbd@cbpf.br; emil@cbpf.br; oaptavares@cbpf.br

    2007-07-01

    A semiempirical model based on the quantum mechanical tunnelling mechanism of alpha emission from nuclei has been extended to systematize the proton decay half-lives of all existing proton emitter nuclides. These nuclei are far from the beta stability line, near the proton drip line, and only a few experimental data are available. This semiempirical model has been well succeeded for the systematization of alpha decay half-lives, and has predicted for new candidates to alpha emission not yet detected. The purpose of the present extended systematization is to offer a useful tool capable to predict new proton emitter nuclides as well as determine their partial proton emission half-lives with good accuracy. (author)

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

    CERN Multimedia

    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.

  11. TOF-Bρ mass measurements of very exotic nuclides for astrophysical calculations at the NSCL

    Science.gov (United States)

    Matoš, M.; Estrade, A.; Amthor, M.; Aprahamian, A.; Bazin, D.; Becerril, A.; Elliot, T.; Galaviz, D.; Gade, A.; Gupta, S.; Lorusso, G.; Montes, F.; Pereira, J.; Portillo, M.; Rogers, A. M.; Schatz, H.; Shapira, D.; Smith, E.; Stolz, A.; Wallace, M.

    2008-01-01

    Atomic masses play a crucial role in many nuclear astrophysics calculations. The lack of experimental values for relevant exotic nuclides triggered a rapid development of new mass measurement devices around the world. The time-of-flight (TOF) mass measurements offer a complementary technique to the most precise one, Penning trap measurements (Blaum 2006 Phys. Rep. 425 1), the latter being limited by the rate and half-lives of the ions of interest. The NSCL facility provides a well-suited infrastructure for the TOF mass measurements of very exotic nuclei. At this facility, we have recently implemented a TOF-Bρ technique and performed mass measurements of neutron-rich nuclides in the Fe region, important for r-process calculations and for calculations of processes occurring in the crust of accreting neutron stars.

  12. The puzzle of the synthesis of the rare nuclide 138La

    Science.gov (United States)

    Goriely, S.; Arnould, M.; Borzov, I.; Rayet, M.

    2001-08-01

    The calculations of the p-process in the O/Ne layers of Type II supernovae are quite successful in reproducing the solar system content of p-nuclides. They predict, however, a significant underproduction of the rare odd-odd nuclide \\chem{138}{La}. A model for the explosion of a 25 Msun star with solar metallicity is used to suggest that nu_e -captures on \\chem{138}{Ba} may well be its most efficient production mechanism. The responsibility of an inadequate prediction of the \\chem{138}{La} and \\chem{139}{La} photodisintegration rates in the too low production of \\chem{138}{La} is also examined quantitatively. A detailed discussion of the theoretical uncertainties in these rates suggest that the required rate changes are probably too high to be fully plausible. Their measurement would be most welcome. They would help disentangling the relative contributions of thermonuclear and neutrino processes to the \\chem{138}{La} production.

  13. The puzzle of the synthesis of the rare nuclide 138La

    CERN Document Server

    Goriely, S; Borzov, I N; Rayet, M

    2001-01-01

    The calculations of the p-process in the O/Ne layers of Type II supernovae are quite successful in reproducung the solar system content of p-nuclides. They predict, however, a significant underproduction of the rare odd-odd nuclide 138La. A model for the explosion of a 25 Mo star with solar metallicity is used to suggest that electron neutrino captures on 138Ba may well be its most efficient production mechanism. The responsibility of an inadequate prediction of the 138La and 139La photodisintegration rates in the too low production of 138La is also examined quantitatively. A detailed discussion of the theoretical uncertainties in these rates suggest that the required rate changes are probably too high to be fully plausible. Their measurement would be most welcome. They would help disentangling the relative contributions of thermonuclear and neutrino processes to the 138La production.

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

    CERN Document Server

    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.

  15. Highly sensitive measurements of radioactive noble gas nuclides in the BOREXINO solar neutrino experiment.

    Science.gov (United States)

    Simgen, H; Heusser, G; Zuzel, G

    2004-01-01

    Low background miniaturized proportional counters as developed for the GALLEX solar neutrino experiment can be applied to the detection of radioactive noble gas nuclides at very low activities. We have developed an apparatus that allows the activity of trace amounts of isotopes of the four noble gases Ar, Kr, Xe and Rn to be measured. The technique includes contamination-free chromatographic purification of raw gas samples and subsequent low-level counting. Minimum detectable activities of 100 microBq and below have been attained. The developed techniques can be used to determine the 222Rn and 85Kr concentration in nitrogen for the solar neutrino experiment BOREXINO. By applying efficient techniques to concentrate noble gases from nitrogen, minimum detectable activity concentrations below 1 microBq/m3 of nitrogen (STP) have been reached for both nuclides.

  16. Precision mass measurements of short-lived nuclides for nuclear structure studies at TITAN

    Directory of Open Access Journals (Sweden)

    Chaudhuri A.

    2014-03-01

    Full Text Available TITAN (TRIUMF’s Ion Trap for Atomic and Nuclear science at TRIUMF’s rare isotope beam facility ISAC is an advanced Penning trap based mass spectrometer dedicated to precise and accurate mass determinations. An overview of TITAN, the measurement technique and a highlight of recent mass measurements of the short-lived nuclides important to the nuclear structure program at TITAN are presented.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. ISOLTRAP mass measurements of exotic nuclides at $\\delta$m/m=10$^{-8}$

    CERN Document Server

    Blaum, K; Beck, D; Bollen, G; Delahaye, P; George, S; Guénaut, C; Herfurth, S; Herlert, Alexander; Kellerbauer, A G; Kluge, H J; Lunney, M D; Mukherjee, M; Schwarz, S; Schweikhard, L; Yazidjian, C

    2005-01-01

    The ISOLTRAP experiment at the ISOLDE facility at CERN is a Penning trap mass spectrometer for on-line mass measurements on short-lived radionuclides. It allows the determination of atomic masses of exotic nuclides with a relative uncertainty of only 10$^{-8}$. The results provide important information for, for example, weak interaction studies and nuclear models. Recent ISOLTRAP investigations and applications of high-precision mass measurements are discussed.

  19. Synchrotron radiation based Mössbauer absorption spectroscopy of various nuclides

    Science.gov (United States)

    Masuda, Ryo; Kobayashi, Yasuhiro; Kitao, Shinji; Kurokuzu, Masayuki; Saito, Makina; Yoda, Yoshitaka; Mitsui, Takaya; Seto, Makoto

    2016-12-01

    Synchrotron-radiation (SR) based Mössbauer absorption spectroscopy of various nuclides is reviewed. The details of the measuring system and analysis method are described. Especially, the following two advantages of the current system are described: the detection of internal conversion electrons and the close distance between the energy standard scatterer and the detector. Both of these advantages yield the enhancement of the counting rate and reduction of the measuring time. Furthermore, SR-based Mössbauer absorption spectroscopy of 40K, 151Eu, and 174Yb is introduced to show the wide applicability of this method. In addition to these three nuclides, SR-based Mössbauer absorption spectroscopy of 61Ni, 73Ge, 119Sn, 125Te, 127I, 149Sm, and 189Os has been performed. We continue to develop the method to increase available nuclides and to increase its ease of use. The complementary relation between the time-domain method using SR, such as nuclear forward scattering and the energy-domain methods such as SR-based Mössbauer absorption spectroscopy is also noted.

  20. Synchrotron radiation based Mössbauer absorption spectroscopy of various nuclides

    Energy Technology Data Exchange (ETDEWEB)

    Masuda, Ryo, E-mail: masudar@rri.kyoto-u.ac.jp; Kobayashi, Yasuhiro; Kitao, Shinji; Kurokuzu, Masayuki; Saito, Makina [Kyoto University, Research Reactor Institute (Japan); Yoda, Yoshitaka [Japan Synchrotron Radiation Research Institute, Resarch and Utilization Division (Japan); Mitsui, Takaya [Japan Atomic Energy Agency, Condensed Matter Science Division, Sector of Nuclear Science Research (Japan); Seto, Makoto [Kyoto University, Research Reactor Institute (Japan)

    2016-12-15

    Synchrotron-radiation (SR) based Mössbauer absorption spectroscopy of various nuclides is reviewed. The details of the measuring system and analysis method are described. Especially, the following two advantages of the current system are described: the detection of internal conversion electrons and the close distance between the energy standard scatterer and the detector. Both of these advantages yield the enhancement of the counting rate and reduction of the measuring time. Furthermore, SR-based Mössbauer absorption spectroscopy of {sup 40}K, {sup 151}Eu, and {sup 174}Yb is introduced to show the wide applicability of this method. In addition to these three nuclides, SR-based Mössbauer absorption spectroscopy of {sup 61}Ni, {sup 73}Ge, {sup 119}Sn, {sup 125}Te, {sup 127}I, {sup 149}Sm, and {sup 189}Os has been performed. We continue to develop the method to increase available nuclides and to increase its ease of use. The complementary relation between the time-domain method using SR, such as nuclear forward scattering and the energy-domain methods such as SR-based Mössbauer absorption spectroscopy is also noted.

  1. Systematics of alpha decay half-life: new evaluations for alpha-emitter nuclides

    Energy Technology Data Exchange (ETDEWEB)

    Medeiros, E.L.; Rodrigues, M.M.N.; Duarte, S.B.; Tavares, O.A.P. E-mail: emil.cbpf.br

    2006-06-15

    A semiempirical model based on the quantum mechanical tunnelling mechanism of alpha emission from nuclei has been used to systematize the alpha decay half-lives of a set of 336 nuclides, comprising all the alpha-emitter nuclides whose T{sub 1/2} {sup a}lpha-data for ground-state to ground-state transitions of mutual angular momentum l = 0 are known. With a minimum of data rejection (only {approx} 5% of cases), the procedure has been successful in reproducing quite satisfactorily (within a factor {approx} 2) most of the cases ({approx} 80%) investigated. The few significant discrepancies found between measured and calculated results are analysed and discussed. Also reported is the prediction from the model for possible new alpha-emitter nuclides, namely {sup 180} W, {sup 184} Os, and {sup 228} Ra for which cases the calculated partial alpha decay half-lives fall within the range of half-lives measurable by the current techniques. (author)

  2. Induced radioactivity studies of the shielding and beamline equipment of the high intensity proton accelerator facility at PSI

    Directory of Open Access Journals (Sweden)

    Otiougova Polina

    2017-01-01

    Full Text Available The Paul Scherrer Institute (PSI is the largest national research center in Switzerland. Its multidisciplinary research is dedicated to a wide ↓eld in natural science and technology as well as particle physics. The High Intensity Proton Accelerator Facility (HIPA has been in operation at PSI since 1974. It includes an 870 keV Cockroft-Walton pre-accelerator, a 72 MeV injector cyclotron as well as a 590 MeV ring cyclotron. The experimental facilities, the meson production graphite targets, Target E and Target M, and the spallation target stations (SINQ and UCN are used for material research and particle physics. In order to ful↓ll the request of the regulatory authorities and to be reported to the regulators, the expected radioactive waste and nuclide inventory after an anticipated ↓nal shutdown in the far future has to be estimated. In this contribution, calculations for the 20 m long beamline between Target E and the 590 MeV beam dump of HIPA are presented. The ↓rst step in the calculations was determining spectra and spatial particle distributions around the beamlines using the Monte-Carlo particle transport code MCNPX2.7.0 [1]. To perform the analysis of the MCNPX output and to determine the radionuclide inventory as well as the speci↓c activity of the nuclides, an activation script [2] using the FISPACT10 code with the cross sections from the European Activation File (EAF2010 [3] was applied. The speci↓c activity values were compared to the currently existing Swiss exemption limits (LE [4] as well as to the Swiss liberation limits (LL [5], becoming e↑ective in the near future. The obtained results were used to estimate the total volume of the radioactive waste produced at HIPA and have to be reported to the Swiss regulatory authorities. The comparison of the performed calculations to measurements is discussed as well.

  3. Future accelerators (?)

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. 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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  5. Compact particle accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Elizondo-Decanini, Juan M.

    2017-08-29

    A compact particle accelerator having an input portion configured to receive power to produce particles for acceleration, where the input portion includes a switch, is provided. In a general embodiment, a vacuum tube receives particles produced from the input portion at a first end, and a plurality of wafer stacks are positioned serially along the vacuum tube. Each of the plurality of wafer stacks include a dielectric and metal-oxide pair, wherein each of the plurality of wafer stacks further accelerate the particles in the vacuum tube. A beam shaper coupled to a second end of the vacuum tube shapes the particles accelerated by the plurality of wafer stacks into a beam and an output portion outputs the beam.

  6. Accelerator mass spectrometry: state of the art

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. Accelerating Value Creation with Accelerators

    DEFF Research Database (Denmark)

    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...... with the traditional audit and legal universes and industries are examples of emerging potentials both from a research and business point of view to exploit and explore further. The accelerator approach may therefore be an Idea Watch to consider, no matter which industry you are in, because in essence accelerators...

  8. Accelerating Value Creation with Accelerators

    DEFF Research Database (Denmark)

    Jonsson, Eythor Ivar

    2015-01-01

    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 accelera......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...... an approach to facilitate implementation and realization of business ideas and is a lucrative approach to transform research into ventures and to revitalize regions and industries in transition. Investors have noticed that the accelerator approach is a way to increase the possibility of success by funnelling...

  9. Studies on the benefit of extended capabilities of the driver accelerator for EURISOL

    CERN Document Server

    Schmidt, K.-H; Lukic, S; Ricciardi, M. V; Veselsky, M

    Possibilities are studied for the optimization of EURISOL rare nuclide yields in specific regions of the nuclear chart by building the driver accelerator in a way that enables accelerating several additional beam species, to specific energies, besides the baseline 1 GeV proton beam. Nuclide production rates with these driver beams are compared to the production rates expected with the 1 GeV proton beam in the direct-production and the high-power-converter scenarios. Arguments are presented to show that several additional driver-beam scenarios could provide substantial benefit for the production of nuclides in specific regions of the nuclear chart. The quantitative values in this report are preliminary in the sense that they depend on assumptions on the values of some key parameters which are subject to technical development, e.g. maximum beam intensities or limits on the target heat load. The different scenarios are compared from the aspect of nuclide yields. The arguments presented here, when complemented by...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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.

  12. Study on immobilization and migration of nuclide u in superficial soil of uranium tailings pond

    Science.gov (United States)

    Chang, Zhe; Zhou, Shukui

    2017-05-01

    The uranium tailings in southern China was used as the object of study to study the fixation and migration characteristics of nuclide U in shallow tailings. The results showed that the precipitation of tailings in the tailings soil was not linearly related to the depth during the acid rain leaching process. Tailings soil in the role of fixatives, when the lime as a fixative, the tailings of different soil uranium in 20 days after the re-precipitation. However, when lime and ammonium phosphate were used as fixing agents, the cumulative precipitation of U had a significant effect, and the migration of uranium was inhibited.

  13. TOF Mass Measurements of Very Exotic Nuclides: an Input for Astrophysical Calculations

    Science.gov (United States)

    Matoš, M.; Estrade, A.; Amthor, M.; Bazin, D.; Becerril, A.; Elliot, T.; Galaviz, D.; Gade, A.; Lorusso, G.; Montes, F.; Pereira, J.; Portillo, M.; Rogers, A. M.; Schatz, H.; Stolz, A.; Aprahamian, A.; Shapira, D.; Smith, E.; Gupta, S.; Wallace, M.

    2007-10-01

    Atomic masses play a crucial role in many nuclear astrophysics calculations. Very exotic nuclei can be accessed by time-of- flight techniques at radioactive beam facilities. The NSCL facility provides a well-suited infrastructure for TOF mass measurements of very exotic nuclei. At this facility, we have recently implemented a TOF-Bρ technique and performed mass measurements of neutron-rich nuclides in the Fe region, important for calculations of the r-process and processes occurring in the crust of accreting neutron stars. Description of the TOF technique, results and future plans related to nuclear astrophysics will be presented.

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  15. Mass measurements of neutron-deficient nuclides close to A=80 with a Penning trap

    Energy Technology Data Exchange (ETDEWEB)

    Kankainen, A.; Elomaa, V.-V.; Eronen, T.; Hager, U.; Hakala, J.; Jokinen, A.; Moore, I.; Penttilae, H.; Peraejaervi, K.; Rahaman, S.; Rinta-Antila, S.; Ronkanen, P.; Saastamoinen, A.; Sonoda, T.; Aeystoe, J. [University of Jyvaeskylae, Department of Physics, P.O. Box 35 (Finland); Batist, L.; Novikov, Yu.N.; Popov, A.V.; Seliverstov, D.M. [Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); Eliseev, S.A.; Vorobjev, G.K. [Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); GSI, Darmstadt (Germany)

    2006-09-15

    The masses of {sup 80,} {sup 81,} {sup 82,} {sup 83}Y, {sup 83,} {sup 84,} {sup 85,} {sup 86,} {sup 88}Zr and {sup 85,} {sup 86,} {sup 87,} {sup 88}Nb have been measured with a typical precision of 7keV by using the Penning trap setup at IGISOL. The mass of {sup 84}Zr has been measured for the first time. These precise mass measurements have improved S{sub p} and Q{sub EC} values for astrophysically important nuclides. (orig.)

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  18. The deep accumulation of 10Be at Utsira, southwestern Norway: Implications for cosmogenic nuclide exposure dating in peripheral ice sheet landscapes

    Science.gov (United States)

    Briner, Jason P.; Goehring, Brent M.; Mangerud, Jan; Svendsen, John Inge

    2016-09-01

    Cosmogenic nuclide exposure dating is a widely used method for constraining past ice sheet histories. We scrutinize a recently published data set of cosmogenic 10Be data from erratic boulders in Norway used to constrain the deglaciation of the western Scandinavian Ice Sheet to 20 ka. Our model of the 10Be inventory in glacial surfaces leads us to conclude that the chronology may be afflicted by the deep subsurface accumulation of 10Be during long-lasting ice-free periods that resulted in 10Be ages >10% too old. We suggest that the majority of the dated erratic boulders contain a uniform level of inherited muon-produced 10Be and were derived from bedrock depths >2.5 m and most likely ~4 m. The implication of our finding is that for landscapes that experience long ice-free periods between brief maximum glacial phases, glacial erosion of >5 m is required to remove detectable traces of inherited 10Be.

  19. RECIRCULATING ACCELERATION

    Energy Technology Data Exchange (ETDEWEB)

    BERG,J.S.; GARREN,A.A.; JOHNSTONE,C.

    2000-04-07

    This paper compares various types of recirculating accelerators, outlining the advantages and disadvantages of various approaches. The accelerators are characterized according to the types of arcs they use: whether there is a single arc for the entire recirculator or there are multiple arcs, and whether the arc(s) are isochronous or non-isochronous.

  20. LIBO accelerates

    CERN Multimedia

    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.

  1. Accelerating Inspire

    CERN Document Server

    AUTHOR|(CDS)2266999

    2017-01-01

    CERN has been involved in the dissemination of scientific results since its early days and has continuously updated the distribution channels. Currently, Inspire hosts catalogues of articles, authors, institutions, conferences, jobs, experiments, journals and more. Successful orientation among this amount of data requires comprehensive linking between the content. Inspire has lacked a system for linking experiments and articles together based on which accelerator they were conducted at. The purpose of this project has been to create such a system. Records for 156 accelerators were created and all 2913 experiments on Inspire were given corresponding MARC tags. Records of 18404 accelerator physics related bibliographic entries were also tagged with corresponding accelerator tags. Finally, as a part of the endeavour to broaden CERN's presence on Wikipedia, existing Wikipedia articles of accelerators were updated with short descriptions and links to Inspire. In total, 86 Wikipedia articles were updated. This repo...

  2. DRENA: A model for the transport of nuclides in drainage slopes

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Olivares, A.; Aguero, A.; Pinedo, P.

    1994-07-01

    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.

  3. Preliminary scenarios and nuclide transport models for low-and intermediate-level repository system

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Youn Myoung; Han, Kyong Won; Hwang, Yong Soo; Kang, Chul Hyung

    2001-02-01

    Through the study 11 scenarios with which nuclide release from the low- and intermediate-level radioactive waste could be simulated and assessed are selected, based upon FEPs identified. For each scenario, some practical methodologies as well as mathematical models involved in modling of nuclide transport in various media are also proposed. It is considered that such methodologies can play a great role when real repository system is constructed and operated in very near future. Real repository system is anticipated not to be quite different with the repository system postulated through this study. Even though there shows very complicated features for relevant parameters associated with various phisical-, geohydrological-, and geochemical situation and even human society as well, it is very necessary to propose the methodologies for a quantitative assessment of the performance of the repository in order to use them as a template on the practical point of view of preliminary safety assessment. Mathematical models proposed could be easily adopted by such common computer codes as, for example, MIMOSA and MASCOT-K.

  4. Cosmogenic nuclide age constraints on Middle Stone Age lithics from Niassa, Mozambique

    Science.gov (United States)

    Mercader, Julio; Gosse, John C.; Bennett, Tim; Hidy, Alan J.; Rood, Dylan H.

    2012-07-01

    The late phases of the Middle Stone Age (MSA) in the East African Rift System (EARS) are known for their evolutionary shifts and association with bottlenecks, transcontinental expansion, and climatic fluctuations. The chronology of MSA sites contemporaneous with these eco-demographic upheavals is uncertain because of the scarcity of datable sites and the poor understanding of their depositional and erosional histories. We apply terrestrial cosmogenic nuclide dating in a stratigraphic section with a complex exposure history to the study of the Luchamange Beds, a widespread sedimentological unit underlying MSA sites from the shores of Lake Niassa (Mozambican EARS). We use an innovative approach, which may be applicable elsewhere, to calculate their age using a Monte Carlo-based Bayesian model that links depth profiles of 26Al and 10Be, and uses other geomorphic and cosmogenic nuclide age constraints on episodic erosion and burial. The age of the basal Luchamange Beds is 42 + 77/-15 ka, and the MSA occupation on top is 29 + 3/-11 ka. These dates suggest temporal overlap between MSA and the earliest Later Stone Age and diversity in cultural manifestations at the end of the MSA.

  5. The miniature accelerator

    CERN Multimedia

    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 ...

  6. HALF-LIVES OF LONG-LIVED A-DECAY, B-DECAY, BB-DECAY AND SPONTANEOUS FISSION NUCLIDES.

    Energy Technology Data Exchange (ETDEWEB)

    HOLDEN,N.E.

    2001-06-29

    In his review of radionuclides for dating purposes, Roth noted that there were a large number of nuclides, normally considered ''stable'' but which are radioactive with a very long half-life. Roth suggested that I review the data on the half-life values of these long-lived nuclides for a discussion session at the next meeting. These half-life values for long-lived nuclides include those due to various decay modes, {alpha}-decay, {beta}-decay, electron capture decay, {beta}{beta}-decay and spontaneous fission decay. This report is preliminary but will provide a quick overview of the extensive table of data on the recommendations from that review.

  7. Decay Study for the very Neutron-Rich Sn Nuclides, $^{135-140}$Sn Separated by Selective Laser Ionization

    CERN Multimedia

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Susumu; Fukuda, Mitsuhiro; Nishimura, Koichi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Watanabe, Hiromasa; Yamano, Naoki

    1997-05-01

    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, {sup 12}C, {sup 14}N, {sup 16}O, {sup 20}Ne and {sup 40}Ar 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)

  9. Horizontal Accelerator

    Data.gov (United States)

    Federal Laboratory Consortium — The Horizontal Accelerator (HA) Facility is a versatile research tool available for use on projects requiring simulation of the crash environment. The HA Facility is...

  10. Collective accelerator for electron colliders

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Future accelerators

    CERN Document Server

    Hübner, K

    1999-01-01

    An overview of the various schemes for electron-positron linear colliders is given and the status of the development of key components and the various test facilities is given. The present studies of muon-muon colliders and very large hadron colliders are summarized including the plans for component development and tests. Accelerator research and development to achieve highest gradients in linear accelerators is outlined. (44 refs).

  12. Transmutation prospect of long-lived nuclear waste induced by high-charge electron beam from laser plasma accelerator

    Science.gov (United States)

    Wang, X. L.; Xu, Z. Y.; Luo, W.; Lu, H. Y.; Zhu, Z. C.; Yan, X. Q.

    2017-09-01

    Photo-transmutation of long-lived nuclear waste induced by a high-charge relativistic electron beam (e-beam) from a laser plasma accelerator is demonstrated. A collimated relativistic e-beam with a high charge of approximately 100 nC is produced from high-intensity laser interaction with near-critical-density (NCD) plasma. Such e-beam impinges on a high-Z convertor and then radiates energetic bremsstrahlung photons with flux approaching 1011 per laser shot. Taking a long-lived radionuclide 126Sn as an example, the resulting transmutation reaction yield is the order of 109 per laser shot, which is two orders of magnitude higher than obtained from previous studies. It is found that at lower densities, a tightly focused laser irradiating relatively longer NCD plasmas can effectively enhance the transmutation efficiency. Furthermore, the photo-transmutation is generalized by considering mixed-nuclide waste samples, which suggests that the laser-accelerated high-charge e-beam could be an efficient tool to transmute long-lived nuclear waste.

  13. Towards a magnetic field stabilization at ISOLTRAP for high-accuracy mass measurements on exotic nuclides

    CERN Document Server

    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.

  14. Evaluation of activated nuclides for Fugen Nuclear Power Station's decommissioning

    Energy Technology Data Exchange (ETDEWEB)

    Shiratori, Yoshitake; Kawagoe, Shinji; Matsui, Yuji; Higashiura, Norikazu [Japan Nuclear Cycle Development Inst., Tsuruga Head Office, Tsuruga, Fukui (Japan); Iwasaki, Seiji [Nuclear Energy System Inc., Tokyo (Japan)

    2002-09-01

    The density and amount of radioactive nuclides in equipment or concrete including the reactor core need to be evaluated for the decommissioning of the Fugen Nuclear Power Station. To prepare for decommissioning, measurement and evaluation of the neutron flux density have been executed mainly during the reactor operation, because neutron flux density is measured under that condition. Activation evaluation is mainly executed by the calculation method, and the results are checked by the sampling measurements. All of the equipments is divided into three parts, inner core part, shielding part, outer shielding part. The neutron flux distribution of two former parts can be evaluated by calculation, but the last part cannot; it is evaluated by measuring the activation foil for many points. These evaluation methods are checked by a small number of sampling measurements. (author)

  15. Beta-spectroscopy of long lived nuclides with a PIPS detector-setup

    Directory of Open Access Journals (Sweden)

    Domula Alexander R.

    2017-01-01

    Full Text Available Several applications in modern nuclear physics, research and engineering are limited by a lack of precise knowledge in spectral shape data for beta-decays. Specifically the interest aims to study spectral data for forbidden decays with respectively long half-lives, which is one of the central activities of our group. For the investigation of those rare beta-decays the group operates a setup of six PIPS detectors in a vacuum chamber built out of low-radioactivity materials. In the long term the setup will be used as low-background-detector for the investigation of rare beta-decays. In order to reduce the measuring-background a muon veto was installed. The characterization of the setup in the energy-range from 20..1000 keV using conversion-electrons is described. A set of useful calibration-nuclides was established to determine energy calibration and efficiencies.

  16. Beta-spectroscopy of long lived nuclides with a PIPS detector-setup

    Science.gov (United States)

    Domula, Alexander R.; Thurn, Jan; Zuber, Kai

    2017-09-01

    Several applications in modern nuclear physics, research and engineering are limited by a lack of precise knowledge in spectral shape data for beta-decays. Specifically the interest aims to study spectral data for forbidden decays with respectively long half-lives, which is one of the central activities of our group. For the investigation of those rare beta-decays the group operates a setup of six PIPS detectors in a vacuum chamber built out of low-radioactivity materials. In the long term the setup will be used as low-background-detector for the investigation of rare beta-decays. In order to reduce the measuring-background a muon veto was installed. The characterization of the setup in the energy-range from 20..1000 keV using conversion-electrons is described. A set of useful calibration-nuclides was established to determine energy calibration and efficiencies.

  17. Study on the environmental movements and distributions of natural radioactive nuclides on the granite area (II)

    Energy Technology Data Exchange (ETDEWEB)

    Morishima, Hiroshige; Koga, Taeko [Kinki Univ., Higashi-Osaka, Osaka (Japan). Atomic Energy Research Inst

    1999-03-01

    The natural radionuclides as K-40, uranium decay series and thorium decay series etc. are widely distributed on environment, but are not uniformly. These have various forms as the sources of terrecial environmental {gamma} radiation and of radon and make wide fluctuation seasonal and spatially on the environment. We have selected Ikeda mineral spring district, Shimane pref., Misasa spa district, Tottori pref., Muro district, Hachibuse district, Nara pref. and Arima spa district, Hyogo-pref. for HBRA, and Kawanishi-shi, Hyogo pref. and Higashi-osaka-shi, Osaka pref. as CA. We have carried out the study on the environmental movement and distribution of natural radioactive nuclides containing radon and decay nuclides. Radon measurements have been carried using cup typed radon and thoron monitors, pico-rad method by active charcoal sampling and Pilon scintillation-cell by grub sampling. Accumulated radon monitors have been used with cellulose nitrate as solid state track detector. Rn-222 concentrations in air at Misasa spa ranged 2 - 150 Bq/m{sup 3} outdoor and 8 - 194 Bq/m{sup 3} indoor. Rn-222 concentrations on Misasa district, Asahi district and Takeda district geologically formed from granite strata are high, and those on Osika district and Mitoku district formed from volcanic rocks (Andesite and Basalt) are low level. Rn-222 concentration variations in well water used as drinking water were 2 - 138 Bq/l (mean value 31 Bq/l) and those in ground waters varied from non detectable to 4620 Bq/l (mean 875 Bq/l) on sampling time and places. Mean Rn-222 concentration in the spring water at Arima spa area, Hyogo prefecture is 26 Bq/l at Tansan spring source and the other spring sources are comparatively low level. (J.P.N.)

  18. Early Acheulean technology in the Rietputs Formation, South Africa, dated with cosmogenic nuclides.

    Science.gov (United States)

    Gibbon, Ryan J; Granger, Darryl E; Kuman, Kathleen; Partridge, Timothy C

    2009-02-01

    An absolute dating technique based on the build-up and decay of (26)Al and (10)Be in the mineral quartz provides crucial evidence regarding early Acheulean hominid distribution in South Africa. Cosmogenic nuclide burial dating of an ancient alluvial deposit of the Vaal River (Rietputs Formation) in the western interior of South Africa shows that coarse gravel and sand aggradation there occurred ca 1.57+/-0.22Ma, with individual ages of samples ranging from 1.89+/-0.19 to 1.34+/-0.22Ma. This was followed by aggradation of laminated and cross-bedded fine alluvium at ca 1.26+/-0.10Ma. The Rietputs Formation provides an ideal situation for the use of the cosmogenic nuclide burial dating method, as samples could be obtained from deep mining pits at depths ranging from 7 to 16 meters. Individual dates provide only a minimum age for the stone tool technology preserved within the deposits. Each assemblage represents a time averaged collection. Bifacial tools distributed throughout the coarse gravel and sand unit can be assigned to an early phase of the Acheulean. This is the first absolute radiometric dated evidence for early Acheulean artefacts in South Africa that have been found outside of the early hominid sites of the Gauteng Province. These absolute dates also indicate that handaxe-using hominids inhabited southern Africa as early as their counterparts in East Africa. The simultaneous appearance of the Acheulean in different parts of the continent implies relatively rapid technology development and the widespread use of large cutting tools in the African continent by ca 1.6Ma.

  19. Can Morasko and Mundrabilla help Reconstructing Production Rates and Nuclear Reaction Cross-Sections for Light Cosmogenic Nuclides?

    Science.gov (United States)

    Merchel, S.; Smith, T.; Leya, I.; Pavetich, S.; Rugel, G.; Scharf, A.; Muszynski, A.

    2016-08-01

    Lighter nuclides of He, Ne, and Ar, and radionuclides Be-10, Al-26, Cl-36 and Ca-41 are measured in troilite, schreibersite and bulk metal of Mundrabilla and Morasko. Traces of S largely enhance Al-26 production. Cl-36-Ar-36 CRE ages are undisturbed.

  20. Activities of the {sup 7}Be and {sup 137}Cs nuclides in mushrooms from Southern and Western Finland

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  1. Progress of Radioactive Waste Treatment Technology:Migration Research Progress of Key Nuclides under Simulated Disposal Conditions

    Institute of Scientific and Technical Information of China (English)

    ZHOU; Duo; LONG; Hao-qi; JIANG; Tao; SONG; Zhi-xin; CHEN; Xi; BAO; Liang-jin; WANG; Bo

    2015-01-01

    Important parameters used in safety evaluation of HLW disposal repository could be provided through migration study of key nuclides under the simulated disposal conditions which is one of the key contents of deep geological disposal research of HLW.In order to clarify migration mechanism and calculate migration

  2. Transfer time and source tracing in the soil - water- -plant system deciphered by the U-and Th-series short-lived nuclides

    Science.gov (United States)

    Rihs, S.; Pierret, M.; Chabaux, F.

    2011-12-01

    Because soils form at the critical interface between the lithosphere and the atmosphere, characterization of the dynamics occurring through this compartment represents an important goal for several scientific fields and/or human activities. However, this issue remains a challenge because soils are complex systems, where a continuous evolution of minerals and organic soil constituents occurs in response to interactions with waters and vegetation. This study aims to investigate the relevance of short-lived nuclides of U- and Th-series to quantify the transfer times and scheme of radionuclides through a soil - water - plant ecosystem. Activities of (226Ra), (228Ra) and (228Th), as well as the long-lived (232Th), were measured by TIMS and gamma-spectrometry in the major compartments of a forested soil section, i.e.: solid soil fractions (exchangeable fraction, secondary phases and inherited primary minerals), waters (seepage soil waters and a spring further down the watershed) and vegetation (fine and coarse roots of beech trees, young and mature leaves). The matching of these nuclides half-live to bio-geochemical processes time-scale and the relatively good chemical analogy of radium with calcium make these isotopes especially suitable to investigate either time or mechanism of transfers within a soil-water-plant system. Indeed, the (228Ra/226Ra) isotopic ratios strongly differ in the range of samples, allowing quantifying the source and duration transfers. Analyses of the various solid soil fractions demonstrate a full redistribution of Ra isotopes between the inherited minerals and secondary soil phases. However, the transfer of these isotopes to the seepage water or to the tree roots does not follow a simple and obvious scheme. Both primary and secondary phases show to contribute to the dissolved radium. However, depending on the season, the tree leaves degradation also produces up to 70% of dissolved radium. Immobilization of a large part of this radium occurs

  3. Accelerator mass spectrometry (AMS) in plutonium analysis.

    Science.gov (United States)

    Strumińska-Parulska, Dagmara I

    The paper summarizes the results of the (240)Pu/(239)Pu atomic ratio studies in atmospheric fallout samples collected in 1986 over Gdynia (Poland) as well as three Baltic fish species collected in 1997 using the accelerator mass spectrometry. A new generation of AMS has been developed during last years and this method is an efficient and good technique to measure long-lived radioisotopes in the environment and provides the most accurate determination of the atomic ratios between (240)Pu and (239)Pu. The nuclide compositions of plutonium in filter samples correspond to their means of production. AMS measurements of atmospheric fallout collected in April showed sufficient increase of the (240)Pu/(239)Pu atomic ratio from 0.28 from March to 0.47. Also such high increase of (240)Pu/(239)Pu atomic ratio, close to reactor core (240)Pu/(239)Pu atomic ratio, was observed in September and equaled 0.47.

  4. 2014 Joint International Accelerator School: Beam Loss and Accelerator Protection

    CERN Document Server

    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...

  5. Sequentially pulsed traveling wave accelerator

    Science.gov (United States)

    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.

  6. 宇宙成因核素埋藏年龄测定及其在地球科学中的应用%TERRESTRIAL IN SITU COSMOGENIC NUCLIDES BURIAL DATING AND ITS APPLICATION IN GEOSCIENCES

    Institute of Scientific and Technical Information of China (English)

    袁兆德; 陈杰; 张会平

    2011-01-01

    原地生成宇宙成因核素埋藏测年方法,在晚新生代沉积物尤其是陆相碎屑沉积物测年上具有广泛的应用前景.在同一岩石或矿物中的宇宙成因核素对,例如26Al和10Be在地表的生成速率比值是固定的,不受纬度和海拔的影响,但是这一核素对分别具有不同的半衰期.在地表经历了暴露的沉积物被埋藏后,该比值会随着时间而降低,因此具有不同的半衰期的核素对(例如26Al/10Be)可以作为一种地质时钟,测年范围在几十万a至5Ma.文中简要介绍了目前常用的4种方法及其应用:暴露-埋藏图解法、深度剖面法、等时线法以及26Al-21Ne和10Be-21Ne法.%Terrestrial in situ cosmogenic nuclides burial dating has a promising application in dating of late Cenozoic detrital sediments,for example,cave sediments,fluvial sediments and moraine. This method relies on a pair of cosmic-ray-produced nuclides that are produced in the same rock or mineral target at a fixed ratio, but have different half-lives. For example, 26Al and 10Be are produced in quartz at 26Al: 10Be = 6.75: 1. The ratio is not affected by latitude and altitude. After sediments are buried, the ratio would become less as time goes. Therefore, 26Al/10Be ratio can be used as a geological clock. The dating range can be from several hundreds of thousand years to five million years. In this article, we introduce four methods and their applications: exposure-burial diagram method,depth profile method,isochron method, 26Al-21Ne and 10Be-21Ne method. Exposure-burial diagram method is often applied to cave sediments dating, for exposure-burial history of cave deposits is easy. Depth profile method is applied to fluvial sediments dating. There is a good application for isochron approach in till-paleosol sequences in North America. 26Al-21Ne and 10Be-21Ne method has a great potential applicaton in future for its larger dating time and less uncertainty than other methods. The dating method still

  7. Accelerated Unification

    OpenAIRE

    Arkani-Hamed, Nima; Cohen, Andrew; Georgi, Howard

    2001-01-01

    We construct four dimensional gauge theories in which the successful supersymmetric unification of gauge couplings is preserved but accelerated by N-fold replication of the MSSM gauge and Higgs structure. This results in a low unification scale of $10^{13/N}$ TeV.

  8. Denudation rates derived from spatially-averaged cosmogenic nuclide analysis in Nelson catchments, South Island, New Zealand

    Science.gov (United States)

    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

  9. 10Be systematics in the Tsangpo-Brahmaputra catchment: the cosmogenic nuclide legacy of the eastern Himalayan syntaxis

    Science.gov (United States)

    Lupker, Maarten; Lavé, Jérôme; France-Lanord, Christian; Christl, Marcus; Bourlès, Didier; Carcaillet, Julien; Maden, Colin; Wieler, Rainer; Rahman, Mustafizur; Bezbaruah, Devojit; Xiaohan, Liu

    2017-08-01

    The Tsangpo-Brahmaputra River drains the eastern part of the Himalayan range and flows from the Tibetan Plateau through the eastern Himalayan syntaxis downstream to the Indo-Gangetic floodplain and the Bay of Bengal. As such, it is a unique natural laboratory to study how denudation and sediment production processes are transferred to river detrital signals. In this study, we present a new 10Be data set to constrain denudation rates across the catchment and to quantify the impact of rapid erosion within the syntaxis region on cosmogenic nuclide budgets and signals. The measured 10Be denudation rates span around 2 orders of magnitude across individual catchments (ranging from 0.03 to > 4 mm yr-1) and sharply increase as the Tsangpo-Brahmaputra flows across the eastern Himalaya. The increase in denudation rates, however, occurs ˜ 150 km downstream of the Namche Barwa-Gyala Peri massif (NBGPm), an area which has been previously characterized by extremely high erosion and exhumation rates. We suggest that this downstream lag is mainly due to the physical abrasion of coarse-grained, low 10Be concentration, landslide material produced within the syntaxis that dilutes the upstream high-concentration 10Be flux from the Tibetan Plateau only after abrasion has transferred sediment to the studied sand fraction. A simple abrasion model produces typical lag distances of 50 to 150 km compatible with our observations. Abrasion effects reduce the spatial resolution over which denudation can be constrained in the eastern Himalayan syntaxis. In addition, we also highlight that denudation rate estimates are dependent on the sediment connectivity, storage, and quartz content of the upstream Tibetan Plateau part of the catchment, which tends to lead to an overestimation of downstream denudation rates. While no direct 10Be denudation measurements were made in the syntaxis, the dilution of the upstream 10Be signal, measured in Tsangpo-Brahmaputra sediments, provides constraints on the

  10. 10Be systematics in the Tsangpo-Brahmaputra catchment: the cosmogenic nuclide legacy of the eastern Himalayan syntaxis

    Directory of Open Access Journals (Sweden)

    M. Lupker

    2017-08-01

    Full Text Available The Tsangpo-Brahmaputra River drains the eastern part of the Himalayan range and flows from the Tibetan Plateau through the eastern Himalayan syntaxis downstream to the Indo-Gangetic floodplain and the Bay of Bengal. As such, it is a unique natural laboratory to study how denudation and sediment production processes are transferred to river detrital signals. In this study, we present a new 10Be data set to constrain denudation rates across the catchment and to quantify the impact of rapid erosion within the syntaxis region on cosmogenic nuclide budgets and signals. The measured 10Be denudation rates span around 2 orders of magnitude across individual catchments (ranging from 0.03 to > 4 mm yr−1 and sharply increase as the Tsangpo-Brahmaputra flows across the eastern Himalaya. The increase in denudation rates, however, occurs  ∼  150 km downstream of the Namche Barwa–Gyala Peri massif (NBGPm, an area which has been previously characterized by extremely high erosion and exhumation rates. We suggest that this downstream lag is mainly due to the physical abrasion of coarse-grained, low 10Be concentration, landslide material produced within the syntaxis that dilutes the upstream high-concentration 10Be flux from the Tibetan Plateau only after abrasion has transferred sediment to the studied sand fraction. A simple abrasion model produces typical lag distances of 50 to 150 km compatible with our observations. Abrasion effects reduce the spatial resolution over which denudation can be constrained in the eastern Himalayan syntaxis. In addition, we also highlight that denudation rate estimates are dependent on the sediment connectivity, storage, and quartz content of the upstream Tibetan Plateau part of the catchment, which tends to lead to an overestimation of downstream denudation rates. While no direct 10Be denudation measurements were made in the syntaxis, the dilution of the upstream 10Be signal, measured in Tsangpo

  11. Investigation of Neutron Spectra and Transmutation of ^{129}I, ^{237}Np and Other Nuclides with 1.5 GeV Protons from the Dubna Nuclotron Using the Electronuclear Setup "Energy plus Transmutation"

    CERN Document Server

    Krivopustov, M I; Balabekyan, A R; Batusov, Yu A; Bielewicz, M; Brandt, R; Chaloun, P; Chultem, D; Dwivedi, K K; Elishev, A F; Fragopoulou, M; Henzl, V; Henzlová, D; Kalinnikov, V G; Kievets, M K; Krása, A; Krizek, F; Kugler, A; Manolopoulou, Metaxia; Mariin, I I; Nourreddine, A; Odoj, R; Pavliouk, A V; Pronskikh, V S; Robotham, H; Siemon, K; Szuta, M; Stegailov, V I; Solnyshkin, A A; Sosnin, A N; Stoulos, S; Tsoupko-Sitnikov, V M; Tumendelger, T; Wojecehowski, A; Wagner, V; Wan, J S; Westmeier, W; Zamani-Valasiadou, M; Kumawat, H; Kumar, V; Zaverioukha, O S; Zhuk, I V

    2004-01-01

    Experiments which are part of the scientific program "Investigations of physical aspects of electronuclear method of energy production and transmutation for radioactive waste of atomic energetics using relativistic beams from the JINR Synchrophasotron/Nuclotron" (project "Energy plus Transmutation") are described. A large lead target surrounded by a four-section uranium blanket with total weight of 206.4 kg natural uranium was irradiated with 1.5 GeV protons from the new cryogenic accelerator Nuclotron. Radiochemical sensors were exposed to the secondary particle fluences inside and on top of the target assembly. Two long-lived radioactive waste of atomic energetics sensors ^{129}I and ^{237}Np (approximately 1 g weight each) and stable nuclides ^{27}Al, ^{59}Co, ^{127}I, ^{139}La, ^{197}Au and ^{209}Bi as well as natural and enriched uranium were used. In addition, various solid state nuclear track detectors and nuclear emulsions were exposed simultaneously. The experimental results confirm the theoretical e...

  12. Particle Accelerators in China

    Science.gov (United States)

    Zhang, Chuang; Fang, Shouxian

    As the special machines that can accelerate charged particle beams to high energy by using electromagnetic fields, particle accelerators have been widely applied in scientific research and various areas of society. The development of particle accelerators in China started in the early 1950s. After a brief review of the history of accelerators, this article describes in the following sections: particle colliders, heavy-ion accelerators, high-intensity proton accelerators, accelerator-based light sources, pulsed power accelerators, small scale accelerators, accelerators for applications, accelerator technology development and advanced accelerator concepts. The prospects of particle accelerators in China are also presented.

  13. U-series nuclides migration from the vadose zone to a chalk aquifer

    Science.gov (United States)

    Hubert, A.; Bourdon, B.; Pili, E.

    2003-04-01

    We have studied the uranium-series disequilibria in chalk aquifer and the vadose zone above it in order to characterise the time scales of radionuclides migration from the water recharge zone of the aquifer to the river. Our field area is located in Champagne (France). The aquifer is characterized by a double porosity: matrix and fracture, providing both a fast and a slow pathways for water flow. We have collected both carbonate rocks and groundwater samples from boreholes and spring and river water from the same area. The boreholes have been drilled along a flow line. Rock/water interaction inside the aquifer induces dissolution and reprecipitation of carbonates, together with a mobilisation of uranium, and additionally the decay of radionuclides results in a-recoil effect particularly for the 234U--238U pair. We have measured uranium and thorium isotopes for carbonates samples from the aquifer by TIMS and multi-collection ICP-MS. The fractionation of uranium and thorium nuclides is distinctive in the various parts of the aquifer. Rock samples from the saturated zone show a depletion in 234U with a (234U/238U) ratio ranging from 0.945 to 0.993 (± 0.005). This indicates that uranium 234U has been released by rock/water interaction over the last million year. Nevertheless, rock samples from the vadose zone display an activity ratio 234U/238U above 1 and range from 1.002 to 1.052 (± 0.005), suggesting uranium reprecipitation possibly by a redox front. (230Th/238U) ratio range from 1.25 to 1.59 (± 0.03) in both saturated and vadose zone, whilst (230Th/232Th) ratio vary from 1.89 to 5.68 (± 0.05) with the highest values for the vadose zone. The 234U--230Th system shows a significant mobility of uranium less than 300 000 years ago within the aquifer. We are curently analysing water samples which will provide us further insights on the migration timescale of uranium-series nuclides in groundwater and will document the processes of groundwater/carbonate interaction.

  14. MUON ACCELERATION

    Energy Technology Data Exchange (ETDEWEB)

    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. Laser acceleration

    Science.gov (United States)

    Tajima, T.; Nakajima, K.; Mourou, G.

    2017-02-01

    The fundamental idea of Laser Wakefield Acceleration (LWFA) is reviewed. An ultrafast intense laser pulse drives coherent wakefield with a relativistic amplitude robustly supported by the plasma. While the large amplitude of wakefields involves collective resonant oscillations of the eigenmode of the entire plasma electrons, the wake phase velocity ˜ c and ultrafastness of the laser pulse introduce the wake stability and rigidity. A large number of worldwide experiments show a rapid progress of this concept realization toward both the high-energy accelerator prospect and broad applications. The strong interest in this has been spurring and stimulating novel laser technologies, including the Chirped Pulse Amplification, the Thin Film Compression, the Coherent Amplification Network, and the Relativistic Mirror Compression. These in turn have created a conglomerate of novel science and technology with LWFA to form a new genre of high field science with many parameters of merit in this field increasing exponentially lately. This science has triggered a number of worldwide research centers and initiatives. Associated physics of ion acceleration, X-ray generation, and astrophysical processes of ultrahigh energy cosmic rays are reviewed. Applications such as X-ray free electron laser, cancer therapy, and radioisotope production etc. are considered. A new avenue of LWFA using nanomaterials is also emerging.

  16. Accelerator transmutation studies at Los Alamos with LAHET, MCNP, and CINDER`90

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, W.B.; England, T.R.; Arthur, E.D. [and others

    1993-09-01

    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.

  17. First Use of High Charge States for Mass Measurements of Short-lived Nuclides in a Penning Trap

    CERN Document Server

    Ettenauer, S; Gallant, A T; Brunner, T; Chowdhury, U; Simon, V V; Brodeur, M; Chaudhuri, A; Mané, E; Andreoiu, C; Audi, G; López-Urrutia, J R Crespo; Delheij, P; Gwinner, G; Lapierre, A; Lunney, D; Pearson, M R; Ringle, R; Ullrich, J; Dilling, J

    2011-01-01

    Penning trap mass measurements of short-lived nuclides have been performed for the first time with highly-charged ions (HCI), using the TITAN facility at TRIUMF. Compared to singly-charged ions, this provides an improvement in experimental precision that scales with the charge state q. Neutron-deficient Rb-isotopes have been charge bred in an electron beam ion trap to q = 8 - 12+ prior to injection into the Penning trap. In combination with the Ramsey excitation scheme, this unique setup creating low energy, highly-charged ions at a radioactive beam facility opens the door to unrivalled precision with gains of 1-2 orders of magnitude. The method is particularly suited for short-lived nuclides such as the superallowed {\\beta} emitter 74Rb (T1/2 = 65 ms). The determination of its atomic mass and an improved QEC-value are presented.

  18. Cosmogenic nuclides in core samples of the Chico L6 chondrite - Evidence for irradiation under high shielding

    Science.gov (United States)

    Garrison, D. H.; Bogard, D. D.; Albrecht, A. A.; Vogt, S.; Herzog, G. F.; Klein, J.; Fink, D.; Dezfouly-Arjomandy, B.; Middleton, R.

    1992-01-01

    Results are presented from an analysis of core samples obtained from different depths of the Chico (New Mexico) L6 chondrite for various cosmogenic nuclides (Be-10, Al-26, and stable isotopes of He, Ne, and Ar). The relationships between the measured abundances of cosmogenic nuclides and cosmogenic Ne-22/Ne-21 ratio were compared with predictions of recent semiempirical models of Graf et al. (1990) and Reedy (1991), and it was found that both models closely reproduce the observed trends and absolute values of the data obtained. Noble gas data indicate that Chico experienced shielding similar to that of Jilin and greater than those of the Knyahinya or the Keyes chondrites. The exposure history for Chico is discussed.

  19. The Performance Assessment of the Detector for the Portable Environmental Radiation Distribution Monitoring System with Rapid Nuclide Recognition

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Uk Jae; Kim, Hee Reyoung [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2015-05-15

    The environment radiation distribution monitoring system measures the radiation using a portable detector and display the overall radiation distribution. Bluetooth and RS-232 communications are used for constructing monitoring system. However RS-232 serial communication is known to be more stable than Bluetooth and also it can use the detector's raw data which will be used for getting the activity of each artificial nuclide. In the present study, the detection and communication performance of the developed detector with RS-232 method is assessed by using standard sources for the real application to the urban or rural environment. Assessment of the detector for the portable environmental radiation distribution monitoring system with rapid nuclide recognition was carried out. It was understood that the raw data of detector could be effectively treated by using RS-232 method and the measurement showed a good agreement with the calculation within the relative error of 0.4 % in maximum.

  20. Magnetic field stabilization for high-accuracy mass measurements on exotic nuclides

    CERN Document Server

    Marie-Jeanne, M; Blaum, K; Djekic, S; Dworschak, M; Hager, U; Herlert, Alexander; Nagy, S; Savreux, R; Schweikhard, L; Stahl, S; Yazidjian, C; Nagy, Sz.

    2007-01-01

    The magnetic-field stability of a mass spectrometer plays a crucial role in precision mass measurements. In the case of mass determination of short-lived nuclides with a Penning trap, major causes of instabilities are temperature fluctuations in the vicinity of the trap and pressure fluctuations 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 fluctuations by at least one order of magnitude downto dT=+/-5mK and dp=+/-50mtorr has been achieved, which corresponds to a relative frequency change of 2.7x10^{-9} and 1.5x10^{-10}, respectively. With this stabilization the frequency determination with the Penning trap only shows a linear temporal drift over several hours on the 10 ppb level due to the finite resistance of the superconducting magnet coils.

  1. Alpha and gamma spectrometry for natural radioactive nuclides around uranium mines and nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, A.M.; Tome, F.V.; Bejarano, J.D.; Aparicio, A.G. (Universidad de Extremadura, Badajoz (Spain). Dept. de Fisica)

    1992-01-01

    Concentration of uranium and [sup 234]U/[sup 238]U and [sup 235]U/[sup 238]U activity ratios were studied in water samples taken in the neighbourhood of two uranium mines ('El Lobo' and 'El Pedregal', Badajoz, Spain), and around two nuclear power plants and their cooling reservoirs (the Central Nuclear de Almaraz, which is working today, and the Central Nuclear de Valdecaballeros, which is in the construction phase), using alpha spectrometry with semiconductor detectors. The Valdecaballeros data were taken to check for comparison with those of the Central Nuclear de Almaraz and with future values after the start of operation. Measurements were also made of all soluble gamma emitting nuclides using a shielded coaxial high purity germanium detector. The data suggest that the mechanisms responsible for the changes in the concentrations and in the [sup 234]U/[sup 238]U activity ratios in surface waters are principally dilution and leaching. (author).

  2. CosmoCalc: An Excel add-in for cosmogenic nuclide calculations

    Science.gov (United States)

    Vermeesch, Pieter

    2007-08-01

    As dating methods using Terrestrial Cosmogenic Nuclides (TCN) become more popular, the need arises for a general-purpose and easy-to-use data reduction software. The CosmoCalc Excel add-in calculates TCN production rate scaling factors (using Lal, Stone, Dunai, and Desilets methods); topographic, snow, and self-shielding factors; and exposure ages, erosion rates, and burial ages and visualizes the results on banana-style plots. It uses an internally consistent TCN production equation that is based on the quadruple exponential approach of Granger and Smith (2000). CosmoCalc was designed to be as user-friendly as possible. Although the user interface is extremely simple, the program is also very flexible, and nearly all default parameter values can be changed. To facilitate the comparison of different scaling factors, a set of converter tools is provided, allowing the user to easily convert cut-off rigidities to magnetic inclinations, elevations to atmospheric depths, and so forth. Because it is important to use a consistent set of scaling factors for the sample measurements and the production rate calibration sites, CosmoCalc defines the production rates implicitly, as a function of the original TCN concentrations of the calibration site. The program is best suited for 10Be, 26Al, 3He, and 21Ne calculations, although basic functionality for 36Cl and 14C is also provided. CosmoCalc can be downloaded along with a set of test data from http://cosmocalc.googlepages.com.

  3. High Accuracy Mass Measurement of the Dripline Nuclides $^{12,14}$Be

    CERN Multimedia

    2002-01-01

    State-of-the art, three-body nuclear models that describe halo nuclides require the binding energy of the halo neutron(s) as a critical input parameter. In the case of $^{14}$Be, the uncertainty of this quantity is currently far too large (130 keV), inhibiting efforts at detailed theoretical description. A high accuracy, direct mass deterlnination of $^{14}$Be (as well as $^{12}$Be to obtain the two-neutron separation energy) is therefore required. The measurement can be performed with the MISTRAL spectrometer, which is presently the only possible solution due to required accuracy (10 keV) and short half-life (4.5 ms). Having achieved a 5 keV uncertainty for the mass of $^{11}$Li (8.6 ms), MISTRAL has proved the feasibility of such measurements. Since the current ISOLDE production rate of $^{14}$Be is only about 10/s, the installation of a beam cooler is underway in order to improve MISTRAL transmission. The projected improvement of an order of magnitude (in each transverse direction) will make this measureme...

  4. β-decay studies of nuclides in the ^100Sn region at NSCL

    Science.gov (United States)

    Lorusso, Giuseppe; Amthor, Alan; Baumann, Thomas; Bazin, Daniel; Becerril, Ana; Crawford, Heather; Estrade, Alfredo; Gade, Alexandra; Ginter, Thomas; Guess, Carol; Hausmann, Mark; Hitt, Wes; Mantica, Paul; Matos, Milan; Meharchand, Rianon; Minamisono, Kei; Montes, Fernando; Perdikakis, Giorgios; Pereira, Jorque; Pinter, Jill; Portillo, Mauritio; Schatz, Hendrik

    2008-10-01

    β-decay nuclides in the immediate neighborhood of ^100Sn, were studied at NSCL using the β-Counting system (BCS) and the Segmented Germanium Array (SeGA). The nuclei of interest were implanted into the BCS double-sided silicon strip detector and properties from both implantations and the subsequent β-decays were recorded on an event-by-event basis, allowing for the direct observation of the half-lives and the β-delayed proton emission branching ratios. The BCS also contains a stack of Si detectors and a Ge planar detector downstream of the implantation detector to measure the total energy of the emitted beta particles, and hence the β-decay end-point energy. The properties of those nuclei are not only relevant for rp-process calculations but also are essential to understand the structure of the single particle states far from the line of stability, providing stringent tests of nuclear models in this region.

  5. Atomic mass measurements of short-lived nuclides around the doubly-magic $^{208}$Pb

    CERN Document Server

    Weber, C; Beck, D; Blaum, K; Bollen, G; Herfurth, F; Kellerbauer, A G; Kluge, H -J; Lunney, D; Schwarz, S

    2008-01-01

    Accurate atomic mass measurements of neutron-deficient and neutron-rich nuclides around the doubly-magic $^{208}$Pb and of neutron-rich cesium isotopes were performed with the Penning trap mass spectrometer ISOLTRAP at ISOLDE/CERN. The masses of $^{145,147}$Cs, $^{181,183}$Tl, $^{186}$Tl$^{m}$, $^{187}$Tl, $^{196}$Tl$^{m}$, $^{205}$Tl, $^{197}$Pb$^{m}$, $^{208}$Pb, $^{190-197}$Bi, $^{209,215,216}$Bi, $^{203,205,229}$Fr, and $^{214,229,230}$Ra were determined. The obtained relative mass uncertainty in the range of $2 \\times 10^{-7}$ to $2 \\times 10^{-8}$ is not only required for safe identification of isomeric states but also allows mapping the detailed structure of the mass surface. A mass adjustment procedure was carried out and the results included into the Atomic Mass Evaluation. The resulting separation energies are discussed and the mass spectrometric and laser spectroscopic data are examined for possible correlations.

  6. Activity concentration of natural radioactive nuclides in nonmetallic industrial raw materials in Japan.

    Science.gov (United States)

    Iwaoka, Kazuki; Tabe, Hiroyuki; Yonehara, Hidenori

    2014-11-01

    Natural materials such as rock, ore, and clay, containing natural radioactive nuclides are widely used as industrial raw materials in Japan. If these are high concentrations, the workers who handle the material can be unknowingly exposed to radiation at a high level. In this study, about 80 nonmetallic natural materials frequently used as industrial raw materials in Japan were comprehensively collected from several industrial companies, and the activity concentrations of (238)U series, (232)Th series and (40)K in the materials was determined by ICP-MS (inductively-coupled plasma mass spectrometer) and gamma ray spectrum analyses. Effective doses to workers handling them were estimated by using methods for dose estimation given in the RP 122. We found the activity concentrations to be lower than the critical values defined by regulatory requirements as described in the IAEA Safety Guide. The maximum estimated effective dose to workers handling these materials was 0.16 mSv y(-1), which was lower than the reference level (1-20 mSv y(-1)) for existing situation given in the ICRP Publ.103.

  7. Cosmogenic nuclide dating of Sahelanthropus tchadensis and Australopithecus bahrelghazali: Mio-Pliocene hominids from Chad.

    Science.gov (United States)

    Lebatard, Anne-Elisabeth; Bourlès, Didier L; Duringer, Philippe; Jolivet, Marc; Braucher, Régis; Carcaillet, Julien; Schuster, Mathieu; Arnaud, Nicolas; Monié, Patrick; Lihoreau, Fabrice; Likius, Andossa; Mackaye, Hassan Taisso; Vignaud, Patrick; Brunet, Michel

    2008-03-04

    Ages were determined at two hominid localities from the Chad Basin in the Djurab Desert (Northern Chad). In the Koro Toro fossiliferous area, KT 12 locality (16 degrees 00'N, 18 degrees 53'E) was the site of discovery of Australopithecus bahrelghazali (Abel) and in the Toros-Menalla fossiliferous area, TM 266 locality (16 degrees 15'N, 17 degrees 29'E) was the site of discovery of Sahelanthropus tchadensis (Toumaï). At both localities, the evolutive degree of the associated fossil mammal assemblages allowed a biochronological estimation of the hominid remains: early Pliocene (3-3.5 Ma) at KT 12 and late Miocene ( approximately 7 Ma) at TM 266. Atmospheric (10)Be, a cosmogenic nuclide, was used to quasicontinuously date these sedimentary units. The authigenic (10)Be/(9)Be dating of a pelite relic within the sedimentary level containing Abel yields an age of 3.58 +/- 0.27 Ma that points to the contemporaneity of Australopithecus bahrelghazali (Abel) with Australopithecus afarensis (Lucy). The 28 (10)Be/(9)Be ages obtained within the anthracotheriid unit containing Toumaï bracket, by absolute dating, the age of Sahelanthropus tchadensis to lie between 6.8 and 7.2 Ma. This chronological constraint is an important cornerstone both for establishing the earliest stages of hominid evolution and for new calibrations of the molecular clock.

  8. Uncertainties in evaluated total cross-section data for 14 nuclides contained in JENDL-3.2

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Masahiro; Shibata, Keiichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1995-10-01

    Variances and covariances of total cross sections have been estimated for 14 nuclides contained in JENDL-3.2. Least-squares analyses using the GMA code were performed to obtain them. Information on the uncertainties of those measurements, which the JENDL-3.2 evaluation was based on, was derived from the associated references and fed into the GMA code system. The results obtained from the present analysis are illustrated. (author).

  9. Oxidative Dissolution of Spent Fuel and Release of Nuclides from a Copper/Iron Canister : Model Developments and Applications

    OpenAIRE

    Liu, Longcheng

    2001-01-01

    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 mechani...

  10. Dependence of nuclear quadrupole resonance transitions on the electric field gradient asymmetry parameter for nuclides with half-integer spins

    Science.gov (United States)

    Cho, Herman

    2016-09-01

    Allowed transition energies and eigenstate expansions have been calculated and tabulated in numerical form as functions of the electric field gradient asymmetry parameter for the zero field Hamiltonian of quadrupolar nuclides with I = 3 / 2 , 5 / 2 , 7 / 2, and 9 / 2. These results are essential to interpret nuclear quadrupole resonance (NQR) spectra and extract accurate values of the electric field gradient tensors. Applications of NQR methods to studies of electronic structure in heavy element systems are proposed.

  11. Accelerators and the Accelerator Community

    Energy Technology Data Exchange (ETDEWEB)

    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.

  12. Molecular modifications by regulating cAMP signaling and oxidant-antioxidant defence mechanisms, produce antidepressant-like effect: A possible mechanism of etazolate aftermaths of impact accelerated traumatic brain injury in rat model.

    Science.gov (United States)

    Jindal, Ankur; Mahesh, Radhakrishnan; Bhatt, Shvetank; Pandey, Dilip

    2016-12-14

    Traumatic brain injury (TBI) is one of the leading cause of psychiatric conditions in patients, amongst which, depression and anxiety are more frequent. Despite the preclinical antidepressant-like effects, clinical development of Phospodiesterase-4 (PDE4) enzyme inhibitors has been hampered due to serious side effect profiles, such as nausea and vomiting. Etazolate (ETZ) is a new generation PDE4 inhibitor with encouraging safety and tolerance profiles. In our previous studies we have addressed that ETZ produces antidepressant-like effects in animal models of depression, however, the underlying mechanism(s) following TBI have not been completely explored. Impact accelerated TBI by weight drop method causes depression-like behavioral deficits in modified open field exploration, hyper-emotionality and sucrose consumption paradigms. TBI not only causes immediate mechanical damage to the brain, but also induces biochemical changes that lead to delayed neural cell loss leading to a secondary injury. The present study examines the antidepressant effects of ETZ on the TBI-induced depression-like behavior deficits and attempts to explore the underlying mechanism. In order to understand the underlying pathology of TBI and mechanism(s) of ETZ in TBI molecular markers namely, brain cAMP, cAMP response element binding protein (pCREB) and brain-derived neurotrophic factor (BDNF) were estimated. Additionally, the level of oxidative (lipid peroxidation) & nitrosative (nitrite) stress markers, along with antioxidant enzymes markers, such as, reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT) were measured. Furthermore, the involvement of hypothalamic-pituitary adrenal (HPA) axis activity in underlying mechanism was also investigated by measuring serum corticosterone (CORT) level. The results revealed that TBI significantly altered cAMP, pCREB and BDNF levels. Moreover, a significant increase in oxidative-nitrosative stress markers levels, while, significant

  13. Determinatiojn of nuclide vectors for the clearance procedure according paragraph 29 of the radiation protection regulations; Ermittlung von Nuklidvektoren im Freigabeverfahren gemaess paragraph 29 Strahlenschutzverordnung

    Energy Technology Data Exchange (ETDEWEB)

    Simic, Sinisa [Fachhochschule Giessen-Friedberg, Giessen (DE). Inst. fuer Medizinische Physik und Strahlenschutz (IMPS)

    2009-07-01

    The new version of the radiation protection regulations the clearance of radioactive materials is regulated by detailed directives. The clearance procedure in the frame of nuclear facility dismantling is now harmonized with respect to the limiting values for clearance. The authors describe the methodology for the determination of nuclide vectors that has been elaborated for practical use within the clearance procedure. The nuclide vector is neither defined in the atomic law, nor in the radiation protection regulations; the nuclide vector does not represent the real nuclide distribution, it is a calculated value that is supposed to be relevant for radiological purposes. Dependent on the model assumptions significant differences in the resulting clearance limits can appear. The applicability of the concept is strongly dependent on the radiological status in the different nuclear facilities.

  14. Feasibility of the $\\beta^-$ Radio-Guided Surgery with a Variety of Radio-Nuclides of Interest to Nuclear Medicine

    CERN Document Server

    Mancini-Terracciano, Carlo; Bencivenga, Gaia; Bocci, Valerio; Cartoni, Antonella; Collamati, Francesco; Fratoddi, Ilaria; Giordano, Alessandro; Indovina, Luca; Marafini, Michela; Morganti, Silvio; Rotili, Dante; Russomando, Andrea; Scotognella, Teresa; Camillocci, Elena Solfaroli; Toppi, Marco; Traini, Giacomo; Venditti, Iole; Faccini, Riccardo

    2016-01-01

    The $\\beta^-$ based radio-guided surgery overcomes the corresponding $\\gamma$ technique in case the background from healthy tissues is relevant. It can be used only in case a radio-tracer marked with $^{90}$Y is available since the current probe prototype was optimized for the emission spectrum of this radio-nuclide. Here we study, with a set of laboratory tests and simulations, the prototype capability in case a different radio-nuclide is chosen among those used in nuclear medicine. As a result we estimate the probe efficiency on electrons and photons as a function of energy and we evaluate the feasibility of a radio-guided surgery exploiting the selected radio-nuclides. We conclude that requiring a 0.1~ml residue to be detected within 1~s by administering 3~MBq/Kg of radio-isotope, the current probe prototype would yield a significant signal in a vast range of values of SUV and TNR in case $^{31}$Si,$^{32}$P, $^{97}$Zr, and $^{188}$Re are used. Conversely, a tuning of the detector would be needed to efficie...

  15. Development of a new nuclide generation and depletion code using a topological solver based on graph theory

    Energy Technology Data Exchange (ETDEWEB)

    Kasselmann, S., E-mail: s.kasselmann@fz-juelich.de [Forschungszentrum Jülich, 52425 Jülich (Germany); Schitthelm, O. [Forschungszentrum Jülich, 52425 Jülich (Germany); Tantillo, F. [Forschungszentrum Jülich, 52425 Jülich (Germany); Institute for Reactor Safety and Reactor Technology, RWTH-Aachen, 52064 Aachen (Germany); Scholthaus, S.; Rössel, C. [Forschungszentrum Jülich, 52425 Jülich (Germany); Allelein, H.-J. [Forschungszentrum Jülich, 52425 Jülich (Germany); Institute for Reactor Safety and Reactor Technology, RWTH-Aachen, 52064 Aachen (Germany)

    2016-09-15

    The problem of calculating the amounts of a coupled nuclide system varying with time especially when exposed to a neutron flux is a well-known problem and has been addressed by a number of computer codes. These codes cover a broad spectrum of applications, are based on comprehensive validation work and are therefore justifiably renowned among their users. However, due to their long development history, they are lacking a modern interface, which impedes a fast and robust internal coupling to other codes applied in the field of nuclear reactor physics. Therefore a project has been initiated to develop a new object-oriented nuclide transmutation code. It comprises an innovative solver based on graph theory, which exploits the topology of nuclide chains and therefore speeds up the calculation scheme. Highest priority has been given to the existence of a generic software interface well as an easy handling by making use of XML files for the user input. In this paper we report on the status of the code development and present first benchmark results, which prove the applicability of the selected approach.

  16. accelerating cavity

    CERN Multimedia

    On the inside of the cavity there 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.

  17. Impact accelerations

    Science.gov (United States)

    Vongierke, H. E.; Brinkley, J. W.

    1975-01-01

    The degree to which impact acceleration is an important factor in space flight environments depends primarily upon the technology of capsule landing deceleration and the weight permissible for the associated hardware: parachutes or deceleration rockets, inflatable air bags, or other impact attenuation systems. The problem most specific to space medicine is the potential change of impact tolerance due to reduced bone mass and muscle strength caused by prolonged weightlessness and physical inactivity. Impact hazards, tolerance limits, and human impact tolerance related to space missions are described.

  18. Induced radioactivity studies of the shielding and beamline equipment of the high intensity proton accelerator facility at PSI

    Science.gov (United States)

    Otiougova, Polina; Bergmann, Ryan; Kiselev, Daniela; Talanov, Vadim; Wohlmuther, Michael

    2017-09-01

    The Paul Scherrer Institute (PSI) is the largest national research center in Switzerland. Its multidisciplinary research is dedicated to a wide ↓eld in natural science and technology as well as particle physics. The High Intensity Proton Accelerator Facility (HIPA) has been in operation at PSI since 1974. It includes an 870 keV Cockroft-Walton pre-accelerator, a 72 MeV injector cyclotron as well as a 590 MeV ring cyclotron. The experimental facilities, the meson production graphite targets, Target E and Target M, and the spallation target stations (SINQ and UCN) are used for material research and particle physics. In order to ful↓ll the request of the regulatory authorities and to be reported to the regulators, the expected radioactive waste and nuclide inventory after an anticipated ↓nal shutdown in the far future has to be estimated. In this contribution, calculations for the 20 m long beamline between Target E and the 590 MeV beam dump of HIPA are presented. The ↓rst step in the calculations was determining spectra and spatial particle distributions around the beamlines using the Monte-Carlo particle transport code MCNPX2.7.0 [1]. To perform the analysis of the MCNPX output and to determine the radionuclide inventory as well as the speci↓c activity of the nuclides, an activation script [2] using the FISPACT10 code with the cross sections from the European Activation File (EAF2010) [3] was applied. The speci↓c activity values were compared to the currently existing Swiss exemption limits (LE) [4] as well as to the Swiss liberation limits (LL) [5], becoming e↑ective in the near future. The obtained results were used to estimate the total volume of the radioactive waste produced at HIPA and have to be reported to the Swiss regulatory authorities. The comparison of the performed calculations to measurements is discussed as well. Note to the reader: the pdf file has been changed on September 22, 2017.

  19. Particle acceleration by ultra-intense laser-plasma interactions

    CERN Document Server

    Nakajima, K

    2002-01-01

    The mechanism of particle acceleration by ultra-increase laser-plasma interaction is explained. Laser light can generate very high electric field by focusing with electromagnetic field matched phase with frequency. 1018 W/cm sup 2 laser light produce about 3 TV/m electric field. Many laser accelerators, which particle acceleration method satisfies phase matching particle and electric field, are proposed. In these accelerators, the Inverse Cherenkov Accelerator, Inverse FEL Accelerator and Laser-Plasma Accelerator are explained. Three laser-plasma acceleration mechanisms: Plasma Beat Wave Accelerator, Laser Wake-Field Accelerator (LWFA) and Self-Modulated LWFA, showed particle acceleration by experiments. By developing a high speed Z pinch capillary-plasma optical waveguide, 2.2 TW and 90 fs laser pulse could be propagated 2 cm at 40 mu m focusing radius in 1999. Dirac acceleration or ultra-relativistic ponderomotive acceleration mechanism can increase energy exponentially. (S.Y.)

  20. Extensive MIS 3 glaciation in southernmost Patagonia revealed by cosmogenic nuclide dating of outwash sediments

    Science.gov (United States)

    Darvill, Christopher M.; Bentley, Michael J.; Stokes, Chris R.; Hein, Andrew S.; Rodés, Ángel

    2015-11-01

    The timing and extent of former glacial advances can demonstrate leads and lags during periods of climatic change and their forcing, but this requires robust glacial chronologies. In parts of southernmost Patagonia, dating pre-global Last Glacial Maximum (gLGM) ice limits has proven difficult due to post-deposition processes affecting the build-up of cosmogenic nuclides in moraine boulders. Here we provide ages for the Río Cullen and San Sebastián glacial limits of the former Bahía Inútil-San Sebastián (BI-SSb) ice lobe on Tierra del Fuego (53-54°S), previously hypothesised to represent advances during Marine Isotope Stages (MIS) 12 and 10, respectively. Our approach uses cosmogenic 10Be and 26Al exposure dating, but targets glacial outwash associated with these limits and uses depth-profiles and surface cobble samples, thereby accounting for surface deflation and inheritance. The data reveal that the limits formed more recently than previously thought, giving ages of 45.6 ka (139.9/-14.3) for the Río Cullen, and 30.1 ka (+45.6/-23.1) for the San Sebastián limits. These dates indicate extensive glaciation in southern Patagonia during MIS 3, prior to the well-constrained, but much less extensive MIS 2 (gLGM) limit. This suggests the pattern of ice advances in the region was different to northern Patagonia, with the terrestrial limits relating to the last glacial cycle, rather than progressively less extensive glaciations over hundreds of thousands of years. However, the dates are consistent with MIS 3 glaciation elsewhere in the southern mid-latitudes, and the combination of cooler summers and warmer winters with increased precipitation, may have caused extensive glaciation prior to the gLGM.

  1. Constraining Landscape History and Glacial Erosivity Using Paired Cosmogenic Nuclides in Upernavik, Northwest Greenland

    Science.gov (United States)

    Corbett, Lee B.; Bierman, Paul R.; Graly, Joseph A.; Neumann, Thomas A.; Rood, Dylan H.

    2013-01-01

    High-latitude landscape evolution processes have the potential to preserve old, relict surfaces through burial by cold-based, nonerosive glacial ice. To investigate landscape history and age in the high Arctic, we analyzed in situ cosmogenic Be(sup 10) and Al (sup 26) in 33 rocks from Upernavik, northwest Greenland. We sampled adjacent bedrock-boulder pairs along a 100 km transect at elevations up to 1000 m above sea level. Bedrock samples gave significantly older apparent exposure ages than corresponding boulder samples, and minimum limiting ages increased with elevation. Two-isotope calculations Al(sup26)/B(sup 10) on 20 of the 33 samples yielded minimum limiting exposure durations up to 112 k.y., minimum limiting burial durations up to 900 k.y., and minimum limiting total histories up to 990 k.y. The prevalence of BE(sup 10) and Al(sup 26) inherited from previous periods of exposure, especially in bedrock samples at high elevation, indicates that these areas record long and complex surface exposure histories, including significant periods of burial with little subglacial erosion. The long total histories suggest that these high elevation surfaces were largely preserved beneath cold-based, nonerosive ice or snowfields for at least the latter half of the Quaternary. Because of high concentrations of inherited nuclides, only the six youngest boulder samples appear to record the timing of ice retreat. These six samples suggest deglaciation of the Upernavik coast at 11.3 +/- 0.5 ka (average +/- 1 standard deviation). There is no difference in deglaciation age along the 100 km sample transect, indicating that the ice-marginal position retreated rapidly at rates of approx.120 m yr(sup-1).

  2. Deglacial history of the Pensacola Mountains, Antarctica from glacial geomorphology and cosmogenic nuclide surface exposure dating

    Science.gov (United States)

    Bentley, M. J.; Hein, A. S.; Sugden, D. E.; Whitehouse, P. L.; Shanks, R.; Xu, S.; Freeman, S. P. H. T.

    2017-02-01

    The retreat history of the Antarctic Ice Sheet is important for understanding rapid deglaciation, as well as to constrain numerical ice sheet models and ice loading models required for glacial isostatic adjustment modelling. There is particular debate about the extent of grounded ice in the Weddell Sea embayment at the Last Glacial Maximum, and its subsequent deglacial history. Here we provide a new dataset of geomorphological observations and cosmogenic nuclide surface exposure ages of erratic samples that constrain the deglacial history of the Pensacola Mountains, adjacent to the present day Foundation Ice Stream and Academy Glacier in the southern Weddell Sea embayment. We show there is evidence of at least two glaciations, the first of which was relatively old and warm-based, and a more recent cold-based glaciation. During the most recent glaciation ice thickened by at least 450 m in the Williams Hills and at least 380 m on Mt Bragg. Progressive thinning from these sites was well underway by 10 ka BP and ice reached present levels by 2.5 ka BP, and is broadly similar to the relatively modest thinning histories in the southern Ellsworth Mountains. The thinning history is consistent with, but does not mandate, a Late Holocene retreat of the grounding line to a smaller-than-present configuration, as has been recently hypothesized based on ice sheet and glacial isostatic modelling. The data also show that clasts with complex exposure histories are pervasive and that clast recycling is highly site-dependent. These new data provide constraints on a reconstruction of the retreat history of the formerly-expanded Foundation Ice Stream, derived using a numerical flowband model.

  3. Study on the environmental movements and distributions of natural radioactive nuclides on the granite area (III)

    Energy Technology Data Exchange (ETDEWEB)

    Morishima, Hiroshige; Koga, Taeko [Kinki Univ., Atomic Energy Research Institute, Higashi-Osaka, Osaka (Japan)

    2000-03-01

    The natural radionuclides as K-40, uranium decay series and thorium decay series etc. are widely distributed on environment, but are not uniformly. These have influences various forms as the sources of terrecial environmental {gamma} radiation and of radon in to the human life environment and make wide fluctuation seasonal and spatially on the environment. The environmental radiation is higher than that of the other on the west Japan where generally consist rich of granite strata. We deeply appreciate in regard to natural radiation and would carry the studies on the movement and distribution of natural radioactive nuclides on high background radiation area consisted rich granite strata. We have selected and observed on Ikeda mineral spring district Ota-shi Shimane pref., Misasa spa district, Tohaku-gun, Tottori pref. on Chugoku area, Muro district Uda-gun, Hachibuse district, Nafa-shi Nara pref., and Arima spa district, Hyogo-pref., Kawanishi-shi, Hyogo pref. on Kinki area and Masutomi spa, Koma-gun, Yamanashi pref., for HBRA, and Higashi-osaka-shi, Osaka pref., for CA. We have carried out the study on the environmental movement and distribution of natural radioactive nuclides containing radon and decay nuclides, and reported these results on following; (1) Radon measurements have been carried using cup typed radon and thoron monitors which are easy handling in spite of need of long sampling period, pico-rad method by active charcoal sampling and Pilon scintillation-cell with 300 ml volume by grub sampling. Accumulated radon monitors have been used cellulose nitrate (LR-115 type II, Kodak Co.) as solid state track detector. Among these characteristics of radon monitors, though minimum detectable limit of cup method for 3 months sampling is higher than those by the other method, it is able to measure mean Rn-222 concentration for 3 months. Rn-222 concentration by pico-rad method is able to get briefly mean concentration for 24 hours, is small detector and many

  4. Hardware Accelerated Simulated Radiography

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. The new 6 MV multi-nuclide AMS facility at the University of Tsukuba

    Energy Technology Data Exchange (ETDEWEB)

    Sasa, Kimikazu, E-mail: ksasa@tac.tsukuba.ac.jp; Takahashi, Tsutomu; Matsumura, Masumi; Matsunaka, Tetsuya; Satou, Yukihiko; Izumi, Daiki; Sueki, Keisuke

    2015-10-15

    The former accelerator mass spectrometry (AMS) system installed on the 12UD Pelletron tandem accelerator at the University of Tsukuba was completely destroyed by the Great East Japan Earthquake on 11 March 2011. A replacement has been designed and constructed at the university as part of the post-quake reconstruction project. It consists of a 6 MV Pelletron tandem accelerator, two multiple cathode AMS ion sources (MC-SNICSs), and a rare-particle detection system. The 6 MV Pelletron tandem accelerator will be applied not only to AMS, but also to areas such as nanotechnology, ion beam analysis, heavy ion irradiation, and nuclear physics. The rare-particle detection system will be capable of measuring environmental levels of long-lived radioisotopes of {sup 10}Be, {sup 14}C, {sup 26}Al, {sup 36}Cl, {sup 41}Ca, and {sup 129}I. It is also expected to measure other radioisotopes such as {sup 32}Si and {sup 90}Sr. The 6 MV Pelletron tandem accelerator was installed in the spring of 2014 at the University of Tsukuba. Routine beam delivery and AMS experiments will start in 2015.

  6. Technology of magnetically driven accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Birx, D.L.; Hawkins, S.A.; Poor, S.E.; Reginato, L.L.; Rogers, D. Jr.; Smith, M.W.

    1985-03-26

    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.

  7. Production and applications of neutrons using particle accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Chichester, David L. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    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.

  8. PRODUCTION AND APPLICATIONS OF NEUTRONS USING PARTICLE ACCELERATORS

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. Application of electron accelerator worldwide

    Energy Technology Data Exchange (ETDEWEB)

    Machi, Sueo [Japan Atomic Industrial Forum, Inc., Tokyo (Japan)

    2003-02-01

    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)

  10. Cosmogenic Nuclide Exposure Dating of the Tiltill Rock Avalanche, Yosemite National Park

    Science.gov (United States)

    Ford, K. R.; Pluhar, C. J.; Stone, J. O.; Stock, G. M.; Zimmerman, S. R.

    2013-12-01

    Yosemite National Park serves as an excellent natural laboratory for studying rock falls and rock avalanches because these are the main processes modifying the nearly vertical slopes of this recently glaciated landscape. Mass wasting represents a significant hazard in the region and the database of previous rock falls and other mass wasting events in Yosemite is extensive, dating back to the mid-1800s. However, this record is too short to capture the recurrence characteristics and triggering mechanisms of the very largest events, necessitating studies of the geologic record of mass wasting. Rock falls and rock avalanches are readily dated by cosmogenic nuclide methods due to their instantaneous formation, and results can be tied to triggering events such as seismic activity (e.g. Stock et al., 2009). Here, we apply exposure dating to the Holocene Tiltill rock avalanche north of Hetch Hetchy Reservoir. The deposit comprises what appear to be two separate lobes of rock and debris, yielding a total volume of ~3.1 x 106 m3. Assuming an erosion rate of 0.0006 cm/yr and neglecting snowpack shielding, preliminary data suggest a mean exposure age of 11,000 + 600 year B.P. for both deposits, indicating that they were emplaced in a single event. The age of the Tiltill 'slide' is similar to earthquakes on the Owens Valley Fault between 10,800 + 600 and 10,200 + 200 cal year B.P. (Bacon, 2007) and the White Mountain Fault, ~10,000 cal year B.P. (Reheis, 1996; DePolo, 1989). Given that movement on the Owens Valley fault in 1872 caused a number of rock falls in Yosemite and the coincidence of ages between the Tiltill 'slide' and paleoseismic events, a large earthquake in Eastern Sierra Nevada may have triggered this event. Other trigger events are also possibilities, but only through compilation of a database of large rock avalanches can statistically significant groupings of events begin to demonstrate whether seismic triggering is a dominant process.

  11. Berkeley Proton Linear Accelerator

    Science.gov (United States)

    Alvarez, L. W.; Bradner, H.; Franck, J.; Gordon, H.; Gow, J. D.; Marshall, L. C.; Oppenheimer, F. F.; Panofsky, W. K. H.; Richman, C.; Woodyard, J. R.

    1953-10-13

    A linear accelerator, which increases the energy of protons from a 4 Mev Van de Graaff injector, to a final energy of 31.5 Mev, has been constructed. The accelerator consists of a cavity 40 feet long and 39 inches in diameter, excited at resonance in a longitudinal electric mode with a radio-frequency power of about 2.2 x 10{sup 6} watts peak at 202.5 mc. Acceleration is made possible by the introduction of 46 axial "drift tubes" into the cavity, which is designed such that the particles traverse the distance between the centers of successive tubes in one cycle of the r.f. power. The protons are longitudinally stable as in the synchrotron, and are stabilized transversely by the action of converging fields produced by focusing grids. The electrical cavity is constructed like an inverted airplane fuselage and is supported in a vacuum tank. Power is supplied by 9 high powered oscillators fed from a pulse generator of the artificial transmission line type.

  12. Particle Accelerator Focus Automation

    Directory of Open Access Journals (Sweden)

    Lopes José

    2017-08-01

    Full Text Available The Laboratório de Aceleradores e Tecnologias de Radiação (LATR at the Campus Tecnológico e Nuclear, of Instituto Superior Técnico (IST has a horizontal electrostatic particle accelerator based on the Van de Graaff machine which is used for research in the area of material characterization. This machine produces alfa (He+ and proton (H+ beams of some μA currents up to 2 MeV/q energies. Beam focusing is obtained using a cylindrical lens of the Einzel type, assembled near the high voltage terminal. This paper describes the developed system that automatically focuses the ion beam, using a personal computer running the LabVIEW software, a multifunction input/output board and signal conditioning circuits. The focusing procedure consists of a scanning method to find the lens bias voltage which maximizes the beam current measured on a beam stopper target, which is used as feedback for the scanning cycle. This system, as part of a wider start up and shut down automation system built for this particle accelerator, brings great advantages to the operation of the accelerator by turning it faster and easier to operate, requiring less human presence, and adding the possibility of total remote control in safe conditions.

  13. Particle Accelerator Focus Automation

    Science.gov (United States)

    Lopes, José; Rocha, Jorge; Redondo, Luís; Cruz, João

    2017-08-01

    The Laboratório de Aceleradores e Tecnologias de Radiação (LATR) at the Campus Tecnológico e Nuclear, of Instituto Superior Técnico (IST) has a horizontal electrostatic particle accelerator based on the Van de Graaff machine which is used for research in the area of material characterization. This machine produces alfa (He+) and proton (H+) beams of some μA currents up to 2 MeV/q energies. Beam focusing is obtained using a cylindrical lens of the Einzel type, assembled near the high voltage terminal. This paper describes the developed system that automatically focuses the ion beam, using a personal computer running the LabVIEW software, a multifunction input/output board and signal conditioning circuits. The focusing procedure consists of a scanning method to find the lens bias voltage which maximizes the beam current measured on a beam stopper target, which is used as feedback for the scanning cycle. This system, as part of a wider start up and shut down automation system built for this particle accelerator, brings great advantages to the operation of the accelerator by turning it faster and easier to operate, requiring less human presence, and adding the possibility of total remote control in safe conditions.

  14. [Bibliographic consideration of proper management of radioactive waste on short-lived period nuclides that are used in nuclear medicine].

    Science.gov (United States)

    Kida, Tetsuo; Watanabe, Hiroshi; Yamaguchi, Ichirou; Nagaoka, Hiroaki; Fujibuchi, Toshioh; Tanaka, Shinji; Hayakawa, Toshio

    2009-05-20

    A rational clearance system for medical radioactive waste has not yet been established in Japan. As Europe and USA's ways, the establishment of DIS that medical radioactive waste what are kept in storage room for more than decided period each nuclide except from regulation of radiation's control. The purpose of this report is to clarify the problems with the establishment of DIS in Japan through a literature review of the experience in Europe and the USA and previous research that has been reported in Japan. To establish the DIS system, the radiation control system in nuclear medicine should be rebuilt and put into effect.

  15. Dependence of nuclear quadrupole resonance transitions on the electric field gradient asymmetry parameter for nuclides with half-integer spins

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Herman

    2016-09-01

    Allowed transition energies and eigenstate expansions have been calculated and tabulated in numerical form as functions of the electric field gradient asymmetry parameter for the zero field Hamiltonian of quadrupolar nuclides with I = 3/2, 5/2, 7/2, and 9/2. These results may be used to interpret nuclear quadrupole resonance (NQR) spectra and extract accurate values of the electric field gradient tensors. Applications of NQR methods to studies of electronic structure in heavy element systems are proposed. This material is based upon work supported by the U.S. Department of Energy Office of Science, Office of Basic Energy Sciences, Heavy Element Chemistry program.

  16. Glacial erosion of high-elevation low-relief summits on passive continental margins constrained by cosmogenic nuclides

    DEFF Research Database (Denmark)

    Andersen, Jane Lund; Egholm, David Lundbek; Knudsen, Mads Faurschou

    We present a new, extensive in-situ cosmogenic 10Be and 26Al dataset from high-elevation low-relief summits along Sognefjorden in Norway. Contrary to previous studies of high-elevation low-relief summits in cold regions, we find only limited cosmogenic nuclide inheritance in bedrock surfaces......, indicating that warm-based ice eroded the summits during the last glacial period. From the isotope concentrations we model denudation histories using a recently developed Monte Carlo Markov Chain inversion model (Knudsen et al, 2015). The model relies on the benthic d18O curve (Lisiecki and Raymo, 2005...

  17. Linear accelerator for radioisotope production

    Energy Technology Data Exchange (ETDEWEB)

    Hansborough, L.D.; Hamm, R.W.; Stovall, J.E.

    1982-02-01

    A 200- to 500-..mu..A 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-..mu..A 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-..mu..A beam, and the cost per beam watt on the target is less than half that of comparable cyclotrons.

  18. Plasma Channel Guided Laser Wakefield Accelerator

    CERN Document Server

    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...

  19. Introduction to Particle Acceleration in the Cosmos

    Science.gov (United States)

    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.

  20. Particle acceleration mechanisms

    CERN Document Server

    Petrosyan, V

    2008-01-01

    We review the possible mechanisms for production of non-thermal electrons which are responsible for non-thermal radiation in clusters of galaxies. Our primary focus is on non-thermal Bremsstrahlung and inverse Compton scattering, that produce hard X-ray emission. We briefly review acceleration mechanisms and point out that in most astrophysical situations, and in particular for the intracluster medium, shocks, turbulence and plasma waves play a crucial role. We consider two scenarios for production of non-thermal radiation. The first is hard X-ray emission due to non-thermal Bremsstrahlung by nonrelativistic particles. Non-thermal tails are produced by accelerating electrons from the background plasma with an initial Maxwellian distribution. However, these tails are accompanied by significant heating and they are present for a short time of <10^6 yr, which is also the time that the tail will be thermalised. Such non-thermal tails, even if possible, can only explain the hard X-ray but not the radio emission...

  1. Electrostatic quadrupole DC accelerators for BNCT applications

    Energy Technology Data Exchange (ETDEWEB)

    Kwan, J.W.; Anderson, O.A.; Reginato, L.L.; Vella, M.C.; Yu, S.S.

    1994-04-01

    A dc electrostatic quadrupole (ESQ) accelerator is capable of producing a 2.5 MeV, 100 mA proton beam for the purpose of generating neutrons for Boron Neutron Capture Therapy. The ESQ accelerator is better than the conventional aperture column in high beam current application due to the presence of stronger transverse field for beam focusing and for suppressing secondary electrons. The major challenge in this type of accelerator is in developing the proper power supply system.

  2. Cyclinacs: Fast-Cycling Accelerators for Hadrontherapy

    OpenAIRE

    Amaldi, U.; Braccini, S.; Citterio, A; Crandall, K.; Crescenti, M.; Dominietto, M.; Giuliacci, A.; Magrin, G.; Mellace, C.; Pearce, P; Pitta', G.; Rosso, E.; Weiss, M.; Zennaro, R.

    2009-01-01

    We propose an innovative fast-cycling accelerator complex conceived and designed to exploit at best the properties of accelerated ion beams for hadrontherapy. A cyclinac is composed by a cyclotron, which can be used also for other valuable medical and research purposes, followed by a high gradient linear accelerator capable to produce ion beams optimized for the irradiation of solid tumours with the most modern techniques. The properties of cyclinacs together with design studies for protons a...

  3. Observations of Collective Ion Acceleration.

    Science.gov (United States)

    1981-01-01

    possible benefit can be listed. In cancer therapy, radiation produced by ion beams may be more selectively directed into tumors. Ion beams in spallation...34Autoresonant Accelerator Concept," Phys. Rev. Lett. 31, 1234 (1973). 50. S. Humphries, J. J. Lee, and R. N. Sudan, "Generation of Incense Pulsed Ion Beams

  4. Spatial and temporal variations in denudation rates derived from cosmogenic nuclides in four European fluvial terrace sequences

    Science.gov (United States)

    Schaller, M.; Ehlers, T. A.; Stor, T.; Torrent, J.; Lobato, L.; Christl, M.; Vockenhuber, C.

    2016-12-01

    The denudation of landscapes is affected by temporal and spatial variations in tectonics, climate, and vegetation. However, deciphering the contributions of these different processes has proven challenging. In this study, cosmogenic nuclide-derived modern and paleo catchment-wide denudation rates in four European rivers are investigated. We present 12 new and 4 recalculated cosmogenic nuclide-derived denudation rates from modern river sediments and 14 paleo-denudation rates from terraces deposited over the last 2 Ma. The catchments studied are located in regions with minimal Quaternary tectonic activity and span different climates over 12o latitude. Results indicate that modern denudation rates range between 16 ± 11 and 51 ± 7 mm/ka with no clear latitudinal variation. Modern denudation rates are compared with catchment geomorphic indices including slope, fluvial steepness index, and relief. The denudation rates correlate better to catchment topographic indices (R2 ≈ 0.4) rather than climate. Paleo-denudation rates range from 8 ± 7 to 56 ± 7 mm/ka and are associated with a possible increase in the average paleo-denudation rates over the past 2 Ma. Taken together, the results indicate that quantification of catchment-wide denudation rates over long (Quaternary) time scales because of climate change is difficult. Future work to study climate influence on denudation rates should focus on the successes of previous work that document transient denudation rates over shorter and more recent time scales, i.e., from the Last Glacial Maximum to present.

  5. Capture and Solidification of Rare Earth Nuclide (Nd) in LiCl-KCl Eutectic Salt Using a Synthetic Inorganic Composite

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Na-Young; Eun, Hee-Chul; Park, Hwan-Seo; Ahn, Do-Hee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2017-06-15

    In this study, neodymium (Nd) nuclides in LiCl-KCl eutectic salts were captured and solidified using a synthetic inorganic composite (Li{sub 2}O-SiO{sub 2}-Al{sub 2}O{sub 3}-B{sub 2}O{sub 3}), a process that allows the selective capture of Nd and fabrication of a composite with Nd captured from waste, without additional additives or mixing. The Nd nuclides in the LiCl-KCl eutectic salt were mainly captured in the form of LiNdSiO{sub 4}, and it was confirmed that NdSiO{sub 3} can be formed in the composite with captured Nd when the content of Nd in the composite is increased. The capture efficiency was higher than about 98 wt%. It was thought that the salt recovered from the Nd capture test was a renewable form could be reused in the pyroprocessing of used nuclear fuel, because the composite has high chemical durability in a LiCl-KCl eutectic salt at 900 ℃. The composite captured Nd was fabricated into a homogeneous glass form and a stable ceramic form.

  6. Retention of simulated fallout nuclides in agricultural crops. 2. Deposition of Cs and Sr on grain crops

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-12-31

    Experiments with artificial wet depositions of {sup 134}Cs and {sup 85}Sr at different times during the growth period were carried out. The studies are complementary to the experiences after the Chernobyl fallout and the results are compared with similar earlier Swedish works on nuclide retention in experiments and on fallout in agriculture. The aim has been to cover the nuclide transfer to grain crops after deposition at different times during the growing period. The initial interception capacity per kg d.w., TRd, seemed to depend on the surface/weight ratio of the plant parts considered. Changes in TRd-values were rapid during the early growth but slower in later stages. The reduction half-time was then often 2 weeks for vegetative parts. Considering the fraction of a deposition retained, FRd, the residence half-time had an average length of 3-4 weeks. During that time there were possibilities for cesium penetration into the plant and further transfer to ears and grain. Strontium did not seem to be transferred that way. There was no increase of cesium in the ears per unit d.w. after the initial interception. However, there was a steady increase in the total content, especially after deposition during the latter half of the growth period when about 5 % was retained of cesium, and 2 % of strontium. The retention of fallout caesium in 1964 was statistically estimated to be of about the same size in Swedish grains 12 refs, 19 figs, 19 tabs

  7. J-dependence of s-wave neutron strength function and presence of intermediate structure in medium and heavy mass nuclides

    Science.gov (United States)

    Badola, Amit; Singhal, S. K.; Bhatnagar, Manoj; Agrawal, H. M.

    2017-01-01

    Neutron resonance structures of nuclides have been studied over a wide energy range as these parameters are used for regulating the inputs to optical and statistical model calculations. On the basis of high resolution data on resonance parameters (E0, Γn, Jπ), s-wave neutron strength functions (S0) for individual Jπ values are calculated and the J-dependence of it has been investigated for 79 odd nuclides. Our analysis of statistical properties shows the J-dependence of (S0) and this contribution should be included in the OM calculations. Our study well materializes the presence of intermediate structure (IS) for 24 odd nuclides within both data and information reported in literature.

  8. Investigation on the movements and the distributions of radon, thoron and their decay nuclides on the life circumstances

    Energy Technology Data Exchange (ETDEWEB)

    Morishima, Hiroshige; Koga, Taeko [Kinki Univ., Higashi-Osaka, Osaka (Japan). Atomic Energy Research Inst

    2001-03-01

    UNSCEAR (2000) reported that the effective doses due to the inhalation of radon and its decay nuclides account on average of the all world for about one-half of all natural sources of radiation. These have great influences on various forms as the sources of terrecial environmental {gamma} radiation and of radon on our life circumstances. Radon and thoron, which are natural gaseous radioactive nuclides released out of rocks and soil etc. are chemical inert and electrically uncharged, but they in the air can spontaneously decay to other metal atoms. And they made a wide fluctuation seasonally and spatially on the environment, but these are not uniformly. We have selected and observed on Misasa spa district, Tottori pref., Kawanishi-shi, Hyogo pref. and Masutomi spa, Yamanashi pref., for HBRA, and Higashi-osaka-shi, Osaka pref., for CA. We have carried out the study on the environmental movement and distribution of natural radioactive nuclides containing radon, thoron and their decay nuclides, and reported these results on following; (1) Radon measurements have been carried using a small pico-rad detector and many sampling points and Pilon scintillation-cell with 300 ml volume by grub sampling. Mean radon concentrations of get briefly for 24 hours are measured to be available on draw of the concentration distribution map. (2) We continued time cource variation of mean radon concentrations on same private house of Misasa spa district. Mean radon concentrations in air for 6 years were fluctuated 6.7-50 Bq/m{sup 3} and 23-170 Bq/m{sup 3} indoor. The mean concentrations on summer and rain season is low level at open-door situation and that on winter is high, as same as these on Kawanishi Hyogo pref.. It was shown that radon outdoor concentrations variation in time course almost have a similar tendency with indoor and the life situation of air ventilation and conditioning are more influenced than variation on area condition. (3) Radon concentrations on Masutomi spa

  9. Terrestrial Cosmogenic-Nuclide Dating of Alluvial Fans in Death Valley, California

    Science.gov (United States)

    Machette, Michael N.; Slate, Janet L.; Phillips, Fred M.

    2008-01-01

    We have used terrestrial cosmogenic nuclides (TCN) to establish the age of some of the most extensive Quaternary alluvial fans in Death Valley, California. These intermediate-age alluvial fans are most extensive on the western side of the valley, where tectonic deformation is considerably less pronounced than on the eastern side of the valley. These fans are characterized by a relatively smooth, densely packed desert pavement formed by well-varnished (blackened) clasts. These surfaces have been mapped as the Q2 gravel by previous workers and as unit Qai (intermediate age) by us. However, the intermediate-age gravels probably contain multiple subunits, as evidenced by slight differences in morphologic expression, soil formation, and inset geomorphic relations. The TCN technique used herein sums the cosmogenic 36Cl in approximately 2.5-meter-deep profiles through soil and host alluvium, thus avoiding some of the problems associated with the more typical surface-exposure dating of boulders or smaller clasts. Our TCN 36Cl dating of 12 depth profiles indicates that these intermediate-age (Qai) alluvial fans range from about 100 to 40 kilo-annum (ka), with a mean age of about 70 ka. An alternative interpretation is that alluvial unit Qai was deposited in two discrete episodes from 90 to 80 ka and from 60 to 50 ka, before and after MIS (marine oxygen-isotope stage) 4 (respectively). Without an intermediate-age unit, such as MIS 4 lake deposits, we can neither disprove nor prove that Qai was deposited in two discrete intervals or over a longer range of time. Thus, in Death Valley, alluvial unit Qai largely brackets MIS 4, which is not associated with a deep phase of Lake Manly. These Qai fans extend to elevations of about -46 meters (150 feet below sea level) and have not been transgressed by Lake Manly, suggesting that MIS 4 or MIS 2 lakes were rather shallow in Death Valley, perhaps because they lacked inflow from surface runoff of the Sierra Nevada drainages through

  10. EDITORIAL: Laser and plasma accelerators Laser and plasma accelerators

    Science.gov (United States)

    Bingham, Robert

    2009-02-01

    This special issue on laser and plasma accelerators illustrates the rapid advancement and diverse applications of laser and plasma accelerators. Plasma is an attractive medium for particle acceleration because of the high electric field it can sustain, with studies of acceleration processes remaining one of the most important areas of research in both laboratory and astrophysical plasmas. The rapid advance in laser and accelerator technology has led to the development of terawatt and petawatt laser systems with ultra-high intensities and short sub-picosecond pulses, which are used to generate wakefields in plasma. Recent successes include the demonstration by several groups in 2004 of quasi-monoenergetic electron beams by wakefields in the bubble regime with the GeV energy barrier being reached in 2006, and the energy doubling of the SLAC high-energy electron beam from 42 to 85 GeV. The electron beams generated by the laser plasma driven wakefields have good spatial quality with energies ranging from MeV to GeV. A unique feature is that they are ultra-short bunches with simulations showing that they can be as short as a few femtoseconds with low-energy spread, making these beams ideal for a variety of applications ranging from novel high-brightness radiation sources for medicine, material science and ultrafast time-resolved radiobiology or chemistry. Laser driven ion acceleration experiments have also made significant advances over the last few years with applications in laser fusion, nuclear physics and medicine. Attention is focused on the possibility of producing quasi-mono-energetic ions with energies ranging from hundreds of MeV to GeV per nucleon. New acceleration mechanisms are being studied, including ion acceleration from ultra-thin foils and direct laser acceleration. The application of wakefields or beat waves in other areas of science such as astrophysics and particle physics is beginning to take off, such as the study of cosmic accelerators considered

  11. Accelerated purification of colloidal silica sols

    Science.gov (United States)

    Bahnsen, E. B.; Garofalini, S.; Pechman, A.

    1979-01-01

    Accelerated purification process for colloidal sols using heat/deionization scheme, sharply reduces waiting time between deionization cycles from several months to a few days. Process produces same high purity silica sols as conventional methods.

  12. Activation and radiation damage in the environment of hadron accelerators

    CERN Document Server

    Kiselev, Daniela

    2013-01-01

    A component which suffers radiation damage usually also becomes radioactive, since the source of activation and radiation damage is the interaction of the material with particles from an accelerator or with reaction products. However, the underlying mechanisms of the two phenomena are different. These mechanisms are described here. Activation and radiation damage can have far-reaching consequences. Components such as targets, collimators, and beam dumps are the first candidates for failure as a result of radiation damage. This means that they have to be replaced or repaired. This takes time, during which personnel accumulate dose. If the dose to personnel at work would exceed permitted limits, remote handling becomes necessary. The remaining material has to be disposed of as radioactive waste, for which an elaborate procedure acceptable to the authorities is required. One of the requirements of the authorities is a complete nuclide inventory. The methods used for calculation of such inventories are presented,...

  13. Accelerator driven sytems from the radiological safety point of view

    Science.gov (United States)

    Sarkar, P. K.; Nandy, Maitreyee

    2007-02-01

    In the proposed accelerator driven systems (ADS) the possible use of several milliamperes of protons of about 1 GeV incident on high mass targets like the molten lead--bismuth eutectic is anticipated to pose radiological problems that have so far not been encountered by the radiation protection community. Spallation reaction products like high energy gammas, neutrons, muons, pions and several radiotoxic nuclides including Po-210 complicate the situation. In the present paper, we discuss radiation safety measures like bulk shielding, containment of radiation leakage through ducts and penetration and induced activity in the structure to protect radiation workers as well as estimation of sky-shine, soil and ground water activation, release of toxic gases to the environment to protect public as per the stipulations of the regulatory authorities. We recommend the application of the probabilistic safety analysis technique by assessing the probability and criticality of different hazard-initiating events using HAZOP and FMECA.

  14. Accelerator driven systems from the radiological safety point of view

    Indian Academy of Sciences (India)

    P K Sarkar; Maitreyee Nandy

    2007-02-01

    In the proposed accelerator driven systems (ADS) the possible use of several milliamperes of protons of about 1 GeV incident on high mass targets like the molten lead–bismuth eutectic is anticipated to pose radiological problems that have so far not been encountered by the radiation protection community. Spallation reaction products like high energy gammas, neutrons, muons, pions and several radiotoxic nuclides including Po-210 complicate the situation. In the present paper, we discuss radiation safety measures like bulk shielding, containment of radiation leakage through ducts and penetration and induced activity in the structure to protect radiation workers as well as estimation of sky-shine, soil and ground water activation, release of toxic gases to the environment to protect public as per the stipulations of the regulatory authorities. We recommend the application of the probabilistic safety analysis technique by assessing the probability and criticality of different hazard-initiating events using HAZOP and FMECA.

  15. Piezoelectric particle accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Kemp, Mark A.; Jongewaard, Erik N.; Haase, Andrew A.; Franzi, Matthew

    2017-08-29

    A particle accelerator is provided that includes a piezoelectric accelerator element, where the piezoelectric accelerator element includes a hollow cylindrical shape, and an input transducer, where the input transducer is disposed to provide an input signal to the piezoelectric accelerator element, where the input signal induces a mechanical excitation of the piezoelectric accelerator element, where the mechanical excitation is capable of generating a piezoelectric electric field proximal to an axis of the cylindrical shape, where the piezoelectric accelerator is configured to accelerate a charged particle longitudinally along the axis of the cylindrical shape according to the piezoelectric electric field.

  16. VLHC accelerator physics

    Energy Technology Data Exchange (ETDEWEB)

    Michael Blaskiewicz et al.

    2001-11-01

    A six-month design study for a future high energy hadron collider was initiated by the Fermilab director in October 2000. The request was to study a staged approach where a large circumference tunnel is built that initially would house a low field ({approx}2 T) collider with center-of-mass energy greater than 30 TeV and a peak (initial) luminosity of 10{sup 34} cm{sup -2}s{sup -1}. The tunnel was to be scoped, however, to support a future upgrade to a center-of-mass energy greater than 150 TeV with a peak luminosity of 2 x 10{sup 34} cm{sup -2} sec{sup -1} using high field ({approx} 10 T) superconducting magnet technology. In a collaboration with Brookhaven National Laboratory and Lawrence Berkeley National Laboratory, a report of the Design Study was produced by Fermilab in June 2001. 1 The Design Study focused on a Stage 1, 20 x 20 TeV collider using a 2-in-1 transmission line magnet and leads to a Stage 2, 87.5 x 87.5 TeV collider using 10 T Nb{sub 3}Sn magnet technology. The article that follows is a compilation of accelerator physics designs and computational results which contributed to the Design Study. Many of the parameters found in this report evolved during the study, and thus slight differences between this text and the Design Study report can be found. The present text, however, presents the major accelerator physics issues of the Very Large Hadron Collider as examined by the Design Study collaboration and provides a basis for discussion and further studies of VLHC accelerator parameters and design philosophies.

  17. APT accelerator. Topical report

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, G.; Rusthoi, D. [comp.] [ed.

    1995-03-01

    The Accelerator Production of Tritium (APT) project, sponsored by Department of Energy Defense Programs (DOE/DP), involves the preconceptual design of an accelerator system to produce tritium for the nation`s stockpile of nuclear weapons. Tritium is an isotope of hydrogen used in nuclear weapons, and must be replenished because of radioactive decay (its half-life is approximately 12 years). Because the annual production requirements for tritium has greatly decreased since the end of the Cold War, an alternative approach to reactors for tritium production, based on a linear accelerator, is now being seriously considered. The annual tritium requirement at the time this study was undertaken (1992-1993) was 3/8 that of the 1988 goal, usually stated as 3/8-Goal. Continued reduction in the number of weapons in the stockpile has led to a revised (lower) production requirement today (March, 1995). The production requirement needed to maintain the reduced stockpile, as stated in the recent Nuclear Posture Review (summer 1994) is approximately 3/16-Goal, half the previous level. The Nuclear Posture Review also requires that the production plant be designed to accomodate a production increase (surge) to 3/8-Goal capability within five years, to allow recovery from a possible extended outage of the tritium plant. A multi-laboratory team, collaborating with several industrial partners, has developed a preconceptual APT design for the 3/8-Goal, operating at 75% capacity. The team has presented APT as a promising alternative to the reactor concepts proposed for Complex-21. Given the requirements of a reduced weapons stockpile, APT offers both significant safety, environmental, and production-fexibility advantages in comparison with reactor systems, and the prospect of successful development in time to meet the US defense requirements of the 21st Century.

  18. Lasers techniques Improvement of classical accelerators by lasers. Laser accelerators with and without plasmas. Lasers accelerators in vacuum

    CERN Document Server

    Hora, Heinrich

    1991-01-01

    Of the unconventional accelerator techniques those including lasers are reported. After explaining the advances by lasers for classical accelerator techniques, as FELs and other methods for 100 GHz generation of GW pulses, a survey is given of far field and near field laser acceleration. Problems of the beat-wave accelerator are discussed and schemes for particle interaction in vacuum without plasma are elaborated. One scheme is the Boreham experiment and another is the acceleration of "standing" wave fields where charged particles are trapped in the intensity minima. Another scheme uses the relativistic acceleration by half waves where the now available petawatt-picosecond laser pulses should produce GeV electron pulses of high luminosity. Increase of these electron enrgies would need very large lasers in the future.

  19. Cosmogenic nuclide concentrations in Neogene rivers of the Great Plains reveal the evolution of fluvial storage and recycling

    Science.gov (United States)

    Sinclair, Hugh; Stuart, Fin; McCann, Louise; Tao, Zui

    2016-04-01

    The measurement of the duration of near surface residence of sediment grains from the stratigraphic record has the potential to quantitatively reconstruct processes such as stratal condensation, sediment recycling and the exposure histories of unconformities. Geomorphological measurements of dates and rates of surfaces and erosion respectively has enabled significant advances in understanding, however, the radiogenic half life of typical cosmogenic nuclides such as 10Be and 26Al means they are not suitable for the stratigraphic record. Instead, we have applied the stable cosmogenic nuclide of 21Ne to quartz-rich sediment to quantify the routing history of the river systems that have drained the southern Rockies of Wyoming and Colorado during Neogene times. The Neogene sediments of Nebraska record fluvial systems of the Great Plains that flow from the Rockies towards the east and into the Mississippi catchment. This succession is climate change. As part of an evaluation of the application of 21Ne to the stratigraphic record, we sampled quartzite pebbles from an Upper Miocene, Pliocene and modern river channel of the North Platte approximately 400 km from their mountainous source. The quartzite is derived from a single exposure of the Medicine Bow quartzites in Wyoming, therefore all three intervals recorded the same travel distance from source. Additionally, we know the erosion rate of the Medicine Bow quartzites from detrital 10Be analyses, and we also sampled shielded bedrock samples from the quartzite to evaluate for any non-cosmogenic 21Ne. This means that the concentrations of 21Ne in detrital pebbles >400 km from their source could be corrected for both inherited non-cosmogenic and erosion induced accumulation at source. Therefore, any additional amounts of 21Ne must record storage and exposure during transport down the river systems. Based on 40 analyses of pebbles from these intervals, we are able to demonstrate that approximately half of the pebbles record

  20. Acceleration without Horizons

    CERN Document Server

    Doria, Alaric

    2015-01-01

    We derive the metric of an accelerating observer moving with non-constant proper acceleration in flat spacetime. With the exception of a limiting case representing a Rindler observer, there are no horizons. In our solution, observers can accelerate to any desired terminal speed $v_{\\infty} < c$. The motion of the accelerating observer is completely determined by the distance of closest approach and terminal velocity or, equivalently, by an acceleration parameter and terminal velocity.

  1. Accelerating flight: Edge with arbitrary acceleration

    CSIR Research Space (South Africa)

    Gledhill, Irvy MA

    2011-11-01

    Full Text Available ? temporal scales ? Euler ? convection ? Reynolds ? translational viscous ? Ekman ? rotational viscous ? Translational acceleration ? related to g ? Rotational accleration ? Rossby ? Coriolis ? Centrifugal ? Gravitational ? CSIR 2009...

  2. A Multibunch Plasma Wakefield Accelerator

    CERN Document Server

    Kallos, Efthymios; Ben-Zvi, Ilan; Katsouleas, Thomas C; Kimura, Wayne D; Kusche, Karl; Muggli, Patric; Pavlishin, Igor; Pogorelsky, Igor; Yakimenko, Vitaly; Zhou, Feng

    2005-01-01

    We investigate a plasma wakefield acceleration scheme where a train of electron microbunches feeds into a high density plasma. When the microbunch train enters such a plasma that has a corresponding plasma wavelength equal to the microbunch separation distance, a strong wakefield is expected to be resonantly driven to an amplitude that is at least one order of magnitude higher than that using an unbunched beam. PIC simulations have been performed using the beamline parameters of the Brookhaven National Laboratory Accelerator Test Facility operating in the configuration of the STELLA inverse free electron laser (IFEL) experiment. A 65 MeV electron beam is modulated by a 10.6 um CO2 laser beam via an IFEL interaction. This produces a train of ~90 microbunches separated by the laser wavelength. In this paper, we present both a simple theoretical treatment and simulation results that demonstrate promising results for the multibunch technique as a plasma-based accelerator.

  3. Virtual gap dielectric wall accelerator

    Science.gov (United States)

    Caporaso, George James; Chen, Yu-Jiuan; Nelson, Scott; Sullivan, Jim; Hawkins, Steven A

    2013-11-05

    A virtual, moving accelerating gap is formed along an insulating tube in a dielectric wall accelerator (DWA) by locally controlling the conductivity of the tube. Localized voltage concentration is thus achieved by sequential activation of a variable resistive tube or stalk down the axis of an inductive voltage adder, producing a "virtual" traveling wave along the tube. The tube conductivity can be controlled at a desired location, which can be moved at a desired rate, by light illumination, or by photoconductive switches, or by other means. As a result, an impressed voltage along the tube appears predominantly over a local region, the virtual gap. By making the length of the tube large in comparison to the virtual gap length, the effective gain of the accelerator can be made very large.

  4. Stochastic Particle Acceleration in Blazar Jets

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The bulk kinetic energy of jets can be dissipated via generating tur bulent plasma waves. We examine stochastic particle acceleration in blazar jets to explain the emissions of all blazars. We show that acceleration of electrons by plasma turbulence waves with a spectrum W(k) ~ k-4/3 produces a nonthermal population of relativistic electrons whose peak frequency of synchrotron emission can fit the observational trends in the spectral energy distribution of all blazars.The plasma nonlinear processes responsible for the formation of turbulent spectrum are investigated. Increases in the interaction time of turbulent waves can produce a flatter speckrum leading to efficient particle acceleration.

  5. Muon Collider Progress: Accelerators

    CERN Document Server

    Zisman, Michael S

    2011-01-01

    A muon collider would be a powerful tool for exploring the energy-frontier with leptons, and would complement the studies now under way at the LHC. Such a device would offer several important benefits. Muons, like electrons, are point particles so the full center-of-mass energy is available for particle production. Moreover, on account of their higher mass, muons give rise to very little synchrotron radiation and produce very little beamstrahlung. The first feature permits the use of a circular collider that can make efficient use of the expensive rf system and whose footprint is compatible with an existing laboratory site. The second feature leads to a relatively narrow energy spread at the collision point. Designing an accelerator complex for a muon collider is a challenging task. Firstly, the muons are produced as a tertiary beam, so a high-power proton beam and a target that can withstand it are needed to provide the required luminosity of ~1 \\times 10^34 cm^-2s^-1. Secondly, the beam is initially produce...

  6. Dynamics of pyroelectric accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Ghaderi, R.; Davani, F. Abbasi, E-mail: fabbasi@sbu.ac.ir [Radiation Application Department, Shahid Beheshti University, Tehran (Iran, Islamic Republic of)

    2015-01-26

    Pyroelectric crystals are used to produce high energy electron beams. We have derived a method to model electric potential generation on LiTaO{sub 3} crystal during heating cycle. In this method, effect of heat transfer on the potential generation is investigated by some experiments. In addition, electron emission from the crystal surface is modeled by measurements and analysis. These spectral data are used to present a dynamic equation of electric potential with respect to thickness of the crystal and variation of its temperature. The dynamic equation's results for different thicknesses are compared with measured data. As a result, to attain more energetic electrons, best thickness of the crystals could be extracted from the equation. This allows for better understanding of pyroelectric crystals and help to study about current and energy of accelerated electrons.

  7. Acceleration of cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Berezhko, E [Yu.G. Shafer Institute of Cosmophysical Research and Aeronomy, 31 Lenin Ave., 677980 Yakutsk (Russian Federation)], E-mail: berezhko@ikfia.ysn.ru

    2008-07-15

    Cosmic ray (CR) origin problem is briefly discussed. It is argued that CRs with energies up to 10{sup 17} eV are produced in galactic supernova remnants, whereas ultra high energy CRs are extragalactic. CR composition strongly changes within the transition from galactic to extragalactic CR component, therefore precise measurements of CR composition at energies 10{sup 17} - 10{sup 19} eV are needed for the reliable determination of this transition. The possible sources of extragalactic CRs are briefly discussed. It is argued that CR acceleration at the shock created by the expanding cocoons around active galactic nuclei has to be considered as a prime candidate for the sources of extragalactic CRs.

  8. Time-separated oscillatory fields for high-precision mass measurements on short-lived Al and Ca nuclides

    CERN Document Server

    George, S; Blank, B; Blaum, K; Breitenfeldt, M; Hager, U; Herfurth, F; Herlert, A; Kellerbauer, A G; Kluge, H J; Kretzschmar, M; Lunney, D; Savreux, R; Schwarz, S; Schweikhard, L; Yazidjian, C

    2008-01-01

    High-precision Penning trap mass measurements on the stable nuclide $^{27}$Al as well as on the short-lived radionuclides $^{26}$Al and $^{38,39}$Ca have been performed by use of radio-frequency excitation with time-separated oscillatory fields, i.e. Ramsey's method, as recently introduced for the excitation of the ion motion in a Penning trap, was applied. A comparison with the conventional method of a single continuous excitation demonstrates its advantage of up to ten times shorter measurements. The new mass values of $^{26,27}$Al clarify conflicting data in this specific mass region. In addition, the resulting mass values of the superallowed $\\beta$-emitter $^{38}$Ca as well as of the groundstate of the $\\beta$-emitter $^{26}$Al$^{m}$ confirm previous measurements and corresponding theoretical corrections of the ft-values.

  9. Nuclide documentation. Element specific parameter values used in the biospheric models of the safety assessments SR 97 and SAFE

    Energy Technology Data Exchange (ETDEWEB)

    Karlsson, Sara; Bergstroem, Ulla [Studsvik Eco and Safety AB, Nykoeping (Sweden)

    2002-05-01

    In this report the element and nuclide specific parameter values used in the biospheric models of the safety assessments SR 97 and SAFE are presented. The references used are presented and where necessary the process of estimation of data is described. The parameters treated in this report are distribution coefficients in soil, organic soil and suspended matter in freshwater and brackish water, root uptake factors for pasturage, cereals, root crops and vegetables, bioaccumulation factors for freshwater fish, brackish water fish, freshwater invertebrates and marine water plants, transfer coefficients for transfer to milk and meat, translocation factors and dose coefficients for external exposure, ingestion (age-dependent values) and inhalation (age-dependent values). The radionuclides treated are those which could be of interest in the two safety assessments. Physical data such as half-lives and type of decay are also presented.

  10. Evolution of the Galaxy and the Birth of the Solar System: The Short-Lived Nuclides Connection

    Indian Academy of Sciences (India)

    S. Sahijpal

    2014-06-01

    An attempt is made, probably for the first time, to understand the origin of the solar system in context with the evolution of the galaxy as a natural consequence of the birth of several generations of stellar clusters. The galaxy is numerically simulated to deduce the inventories of the short-lived nuclides, 26Al, 36Cl, 41Ca, 53Mn and 60Fe, from the stellar nucleosynthetic contributions of the various stellar clusters using an -body simulation with updated prescriptions of the astrophysical processes. The galaxy is evolved by considering the discreteness associated with the stellar clusters and individual stars. We estimate the steady state abundance of the radionuclides around 4.56 billion years ago at the time of formation of the solar system. Further, we also estimate the present 26Al/27Al and 60Fe/56Fe of the interstellar medium that match within a factor of two with the observed estimates. In contrary to the conventional Galactic Chemical Evolution (GCE) model, the present adopted numerical approach provides a natural framework to understand the astrophysical environment related with the origin of the solar system. We deduce the nature of the two stellar clusters; the one that formed and evolved prior to the solar system formation, and the other within which the solar system that was probably formed. The former could have contributed to the short-lived nuclides 129I and 53Mn, whereas, the supernova associated with the most massive star in the latter contributed 26Al and 60Fe to the solar system. The analysiswas performed with the revised solar metallicity of 0.014

  11. Removal of radio nuclides of the U- and Th- series from aqueous solutions by adsorption onto Polyacryamide-expanded perlite: Effects of pH, concentration and temperature

    Science.gov (United States)

    Akkaya, Recep

    2012-10-01

    Poly (Acryamide-expanded perlite) [P(AAm-EP)], was synthesized. The influence of process parameters: initial pH and five radio nuclides of the U- and Th- series (TI+, Ra2+, Bi3+, Ac3+ and Pb2+ in a leaching solution) concentration, on sorption thermodynamic was studied and discussed. The five natural radio nuclides were counted by gamma spectrometer using a type NAI (Tl) detector. The amounts of five radio nuclides sorbed at equlibrium were well represented by Langmuir and Freundlich type isotherms. The Langmuir adsorption capacities (XL) were in the order of 208Tl (0.4 MBq kg-1)>212Pb and 212Bi (0.3 MBq kg-1)>228Ac and (0.1 MBq kg-1)>226Ra (0.04 MBq kg-1). These results demonstrated that P(AAm-EP) had high affinity to the five natural radio nuclides. In order to specify the type of adsorption reaction, thermodynamic parameters such as the standard enthalpy, entropy, and Gibbs free energy were also determined. It was also demonstrated that the adsorption mechanism was spontaneous (ΔG0). The composite was reused for four more times after regeneration without any detectable changes either in its structure or adsorptive capability.

  12. Miocene to recent ice elevation variations from the interior of the West Antarctic ice sheet: Constraints from geologic observations, cosmogenic nuclides and ice sheet modeling

    Science.gov (United States)

    Mukhopadhyay, Sujoy; Ackert, Robert P.; Pope, Allen E.; Pollard, David; DeConto, Robert M.

    2012-07-01

    Observations of long-term West Antarctic Ice Sheet (WAIS) behavior can be used to test and constrain dynamic ice sheet models. Long-term observational constraints are however, rare. Here we present the first constraints on long-term (Miocene-Holocene) WAIS elevation from the interior of the ice sheet near the WAIS divide. We use geologic observations and measurements of cosmogenic 21Ne and 10Be in bedrock surfaces to constrain WAIS elevation variations to WAIS elevations to have been similar to, or lower than present, since the beginning of the Pliocene warm period. We use a continental ice sheet model to simulate the history of ice cover at our sampling sites and thereby compute the expected concentration of the cosmogenic nuclides. The ice sheet model indicates that during the past 5 Ma interior WAIS elevations of >65 m above present-day ice levels at the Ohio Range occur only rarely during brief ice sheet highstands, consistent with the observed cosmogenic nuclide data. Furthermore, the model's prediction that highstand elevations have increased on average since the Pliocene is in good agreement with the cosmogenic nuclide data that indicate the highest ice elevation over the past 5 Ma was reached during the highstand at 11 ka. Since the simulated cosmogenic nuclide concentrations derived from the model's ice elevation history are in good agreement with our measurements, we suggest that the model's prediction of more frequent collapsed-WAIS states and smaller WAIS volumes during the Pliocene are also correct.

  13. HETC-3STEP calculations of proton induced nuclide production cross sections at incident energies between 20 MeV and 5 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Takada, Hiroshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Yoshizawa, Nobuaki; Ishibashi, Kenji

    1996-08-01

    For the OECD/NEA code intercomparison, nuclide production cross sections of {sup 16}O, {sup 27}Al, {sup nat}Fe, {sup 59}Co, {sup nat}Zr and {sup 197}Au for the proton incidence with energies of 20 MeV to 5 GeV are calculated with the HETC-3STEP code based on the intranuclear cascade evaporation model including the preequilibrium and high energy fission processes. In the code, the level density parameter derived by Ignatyuk, the atomic mass table of Audi and Wapstra and the mass formula derived by Tachibana et al. are newly employed in the evaporation calculation part. The calculated results are compared with the experimental ones. It is confirmed that HETC-3STEP reproduces the production of the nuclides having the mass number close to that of the target nucleus with an accuracy of a factor of two to three at incident proton energies above 100 MeV for {sup nat}Zr and {sup 197}Au. However, the HETC-3STEP code has poor accuracy on the nuclide production at low incident energies and the light nuclide production through the fragmentation process induced by protons with energies above hundreds of MeV. Therefore, further improvement is required. (author)

  14. Detailed deposition density maps constructed by large-scale soil sampling for gamma-ray emitting radioactive nuclides from the Fukushima Dai-ichi Nuclear Power Plant accident.

    Science.gov (United States)

    Saito, Kimiaki; Tanihata, Isao; Fujiwara, Mamoru; Saito, Takashi; Shimoura, Susumu; Otsuka, Takaharu; Onda, Yuichi; Hoshi, Masaharu; Ikeuchi, Yoshihiro; Takahashi, Fumiaki; Kinouchi, Nobuyuki; Saegusa, Jun; Seki, Akiyuki; Takemiya, Hiroshi; Shibata, Tokushi

    2015-01-01

    Soil deposition density maps of gamma-ray emitting radioactive nuclides from the Fukushima Dai-ichi Nuclear Power Plant (NPP) accident were constructed on the basis of results from large-scale soil sampling. In total 10,915 soil samples were collected at 2168 locations. Gamma rays emitted from the samples were measured by Ge detectors and analyzed using a reliable unified method. The determined radioactivity was corrected to that of June 14, 2011 by considering the intrinsic decay constant of each nuclide. Finally the deposition maps were created for (134)Cs, (137)Cs, (131)I, (129m)Te and (110m)Ag. The radioactivity ratio of (134)Cs-(137)Cs was almost constant at 0.91 regardless of the locations of soil sampling. The radioactivity ratios of (131)I and (129m)Te-(137)Cs were relatively high in the regions south of the Fukushima NPP site. Effective doses for 50 y after the accident were evaluated for external and inhalation exposures due to the observed radioactive nuclides. The radiation doses from radioactive cesium were found to be much higher than those from the other radioactive nuclides.

  15. Systems and methods for the magnetic insulation of accelerator electrodes in electrostatic accelerators

    Science.gov (United States)

    Grisham, Larry R

    2013-12-17

    The present invention provides systems and methods for the magnetic insulation of accelerator electrodes in electrostatic accelerators. Advantageously, the systems and methods of the present invention improve the practically obtainable performance of these electrostatic accelerators by addressing, among other things, voltage holding problems and conditioning issues. The problems and issues are addressed by flowing electric currents along these accelerator electrodes to produce magnetic fields that envelope the accelerator electrodes and their support structures, so as to prevent very low energy electrons from leaving the surfaces of the accelerator electrodes and subsequently picking up energy from the surrounding electric field. In various applications, this magnetic insulation must only produce modest gains in voltage holding capability to represent a significant achievement.

  16. Radiological accidents: methodologies of radio nuclides dis incorporation; Accidentes radiologicos: metodologias de desincorporacion de radionuclidos

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez F, E. A. [Universidad Autonoma del Estado de Mexico, Facultad de Medicina, Paseo Tollocan s/n, 50180 Toluca, Estado de Mexico (Mexico); Paredes G, L. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Cortes, A., E-mail: lydia.paredes@inin.gob.mx [Comision Nacional de Seguridad Nuclear y Salvaguardias, Dr. Jose Ma. Barragan No. 779, Col. Narvarte, 03020 Mexico D. F. (Mexico)

    2014-08-15

    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)

  17. Role of Direct Laser Acceleration of Electrons in a Laser Wakefield Accelerator with Ionization Injection

    Science.gov (United States)

    Shaw, J. L.; Lemos, N.; Amorim, L. D.; Vafaei-Najafabadi, N.; Marsh, K. A.; Tsung, F. S.; Mori, W. B.; Joshi, C.

    2017-02-01

    We show the first experimental demonstration that electrons being accelerated in a laser wakefield accelerator operating in the forced or blowout regimes gain significant energy from both the direct laser acceleration (DLA) and the laser wakefield acceleration mechanisms. Supporting full-scale 3D particle-in-cell simulations elucidate the role of the DLA of electrons in a laser wakefield accelerator when ionization injection of electrons is employed. An explanation is given for how electrons can maintain the DLA resonance condition in a laser wakefield accelerator despite the evolving properties of both the drive laser and the electrons. The produced electron beams exhibit characteristic features that are indicative of DLA as an additional acceleration mechanism.

  18. Highly efficient accelerator of dense matter using laser-induced cavity pressure acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Badziak, J.; Jablonski, S.; Pisarczyk, T.; Raczka, P.; Chodukowski, T.; Kalinowska, Z.; Parys, P.; Rosinski, M.; Borodziuk, S. [Institute of Plasma Physics and Laser Microfusion, 01-497 Warsaw (Poland); Krousky, E. [Institute of Physics, AS CR, 182 21 Prague 8 (Czech Republic); Liska, R.; Kucharik, M. [Czech Technical University, FNSPE, 160 41 Prague 6 (Czech Republic); Ullschmied, J. [Institute of Plasma Physics, AS CR, 182 20 Prague 8 (Czech Republic)

    2012-05-15

    Acceleration of dense matter to high velocities is of high importance for high energy density physics, inertial confinement fusion, or space research. The acceleration schemes employed so far are capable of accelerating dense microprojectiles to velocities approaching 1000 km/s; however, the energetic efficiency of acceleration is low. Here, we propose and demonstrate a highly efficient scheme of acceleration of dense matter in which a projectile placed in a cavity is irradiated by a laser beam introduced into the cavity through a hole and then accelerated in a guiding channel by the pressure of a hot plasma produced in the cavity by the laser beam or by the photon pressure of the ultra-intense laser radiation trapped in the cavity. We show that the acceleration efficiency in this scheme can be much higher than that achieved so far and that sub-relativisitic projectile velocities are feasible in the radiation pressure regime.

  19. 2014 CERN Accelerator Schools: Plasma Wake Acceleration

    CERN Multimedia

    2014-01-01

    A specialised school on Plasma Wake Acceleration will be held at CERN, Switzerland from 23-29 November, 2014.   This course will be of interest to staff and students in accelerator laboratories, university departments and companies working in or having an interest in the field of new acceleration techniques. Following introductory lectures on plasma and laser physics, the course will cover the different components of a plasma wake accelerator and plasma beam systems. An overview of the experimental studies, diagnostic tools and state of the art wake acceleration facilities, both present and planned, will complement the theoretical part. Topical seminars and a visit of CERN will complete the programme. Further information can be found at: http://cas.web.cern.ch/cas/PlasmaWake2014/CERN-advert.html http://indico.cern.ch/event/285444/

  20. Determination of the specific activities of the cosmogenic nuclides {sup 10}Be and {sup 26}Al in meteorites from the Sahara by means of accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Meltzow, B. [Koeln Univ. (Germany). Abt. Nuklearchemie; Herpers, U. [Koeln Univ. (Germany). Abt. Nuklearchemie; Romstedt, J. [Muenster Univ. (Germany). Inst. fuer Planetologie; Dittrich-Hannen, B. [Eidgenoessische Technische Hochschule, Zurich (Switzerland). Inst. fuer Teilchenphysik; Kubik, P.W. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Suter, M. [Eidgenoessische Technische Hochschule, Zurich (Switzerland). Inst. fuer Teilchenphysik

    1996-06-01

    In 30 samples of meteorites from the Sahara the specific activity of {sup 26}Al, and in the case of rare meteorite types also that of {sup 10}Be was determined. In most cases, the measured data are consistent with the suggestions about possible pairings which were based on mineralogical and petrographical investigations. The investigated CR and CH chondrites were found to be saturated in {sup 26}Al and {sup 10}Be. The {sup 26}Al and {sup 10}Be production rates can be assumed to be (44.5{+-}0.9) dpm/kg and (20.7{+-}0.3) dpm/kg, respectively, for CR as well as (30.1{+-}0.9) dpm/kg and (16.7{+-}0.4) dpm/kg for CH chondrites. Furthermore the {sup 26}Al data of 11 ordinary chondrites can also be interpreted as saturation activities and allow the assumption of 3.10{sup 6} y to be the lower limit of the exposure ages of these meteorites. In the case of Acfer 277, in addition to the {sup 10}Be and {sup 26}Al determinations, a study on nuclear tracks was performed. These data suggest that the investigated sample was located at no more than 8 cm below the original surface of a meteoroid of a radius between 25 cm and 65 cm which traveled through space (0.3{+-}0.1).10{sup 6} y before entering the earth`s atmosphere. (orig.)

  1. Removal of radio nuclides of the U- and Th- series from aqueous solutions by adsorption onto Polyacryamide-expanded perlite: Effects of pH, concentration and temperature

    Energy Technology Data Exchange (ETDEWEB)

    Akkaya, Recep, E-mail: rakkaya@cumhuriyet.edu.tr [Cumhuriyet Univ. Vocat. Sch. Hlth. Serv. TR. 58140, Sivas (Turkey)

    2012-10-01

    Poly (Acryamide-expanded perlite) [P(AAm-EP)], was synthesized. The influence of process parameters: initial pH and five radio nuclides of the U- and Th- series (TI{sup +}, Ra{sup 2+}, Bi{sup 3+}, Ac{sup 3+} and Pb{sup 2+} in a leaching solution) concentration, on sorption thermodynamic was studied and discussed. The five natural radio nuclides were counted by gamma spectrometer using a type NAI (Tl) detector. The amounts of five radio nuclides sorbed at equlibrium were well represented by Langmuir and Freundlich type isotherms. The Langmuir adsorption capacities (X{sub L}) were in the order of {sup 208}Tl (0.4 MBq kg{sup -1})>{sup 212}Pb and {sup 212}Bi (0.3 MBq kg{sup -1})>{sup 228}Ac and (0.1 MBq kg{sup -1})>{sup 226}Ra (0.04 MBq kg{sup -1}). These results demonstrated that P(AAm-EP) had high affinity to the five natural radio nuclides. In order to specify the type of adsorption reaction, thermodynamic parameters such as the standard enthalpy, entropy, and Gibbs free energy were also determined. It was also demonstrated that the adsorption mechanism was spontaneous ({Delta}G<0), the process was exothermic ({Delta}H<0) thus increasing entropy ({Delta}S>0). The composite was reused for four more times after regeneration without any detectable changes either in its structure or adsorptive capability. -- Highlights: Black-Right-Pointing-Pointer The composite provide an enhanced adsorption uptake for radio nuclides of the U- and Th-series ions. Black-Right-Pointing-Pointer The composite can be applied to the Langmuir and Freundlich models. Black-Right-Pointing-Pointer Thermodynamic parameters indicated adsorption process was spontaneous, exothermic. Black-Right-Pointing-Pointer The P(HEMA-EP) composite is reused up to 5 times with no loss of removal efficiency.

  2. Characterisation of electron beams from laser-driven particle accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Brunetti, E.; Manahan, G. G.; Shanks, R. P.; Islam, M. R.; Ersfeld, B.; Anania, M. P.; Cipiccia, S.; Issac, R. C.; Vieux, G.; Welsh, G. H.; Wiggins, S. M.; Jaroszynski, D. A. [Physics Department, University of Strathclyde, Glasgow G4 0NG (United Kingdom)

    2012-12-21

    The development, understanding and application of laser-driven particle accelerators require accurate measurements of the beam properties, in particular emittance, energy spread and bunch length. Here we report measurements and simulations showing that laser wakefield accelerators can produce beams of quality comparable to conventional linear accelerators.

  3. Accelerating structure with linear excitation

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, J.; Srinivasan-Rao, T.

    1988-03-01

    The switched power linac (SPL) structures require a ring-shaped laser beam pulse of uniform intensity to avoid transverse field components of the accelerating field at the center. In order to also utilize the reflection of the outgoing EM wave, the switching element has to be very close to the outer edge of the structure to ensure nearly synchronous superposition at the beam hole with the original inward going wave. It is sometimes easier to produce linear (flat) laser beams, e.g., from powerful excimer lasers which have beams of rectangular cross section. Such flat beams could be used to excite linear photocathode switches or be used to produce flat electron beam pulses in electron sources. In this paper, an accelerator structure is proposed which may be considered a variant of the SPL disk structure, but could be used with linear beams. The structure utilizes a double parabolic horn. 8 refs., 9 figs.

  4. High Energy Particle Accelerators

    CERN Multimedia

    Audio Productions, Inc, New York

    1960-01-01

    Film about the different particle accelerators in the US. Nuclear research in the US has developed into a broad and well-balanced program.Tour of accelerator installations, accelerator development work now in progress and a number of typical experiments with high energy particles. Brookhaven, Cosmotron. Univ. Calif. Berkeley, Bevatron. Anti-proton experiment. Negative k meson experiment. Bubble chambers. A section on an electron accelerator. Projection of new accelerators. Princeton/Penn. build proton synchrotron. Argonne National Lab. Brookhaven, PS construction. Cambridge Electron Accelerator; Harvard/MIT. SLAC studying a linear accelerator. Other research at Madison, Wisconsin, Fixed Field Alternate Gradient Focusing. (FFAG) Oakridge, Tenn., cyclotron. Two-beam machine. Comments : Interesting overview of high energy particle accelerators installations in the US in these early years. .

  5. Improved plasma accelerator

    Science.gov (United States)

    Cheng, D. Y.

    1971-01-01

    Converging, coaxial accelerator electrode configuration operates in vacuum as plasma gun. Plasma forms by periodic injections of high pressure gas that is ionized by electrical discharges. Deflagration mode of discharge provides acceleration, and converging contours of plasma gun provide focusing.

  6. Accelerator Technology Division

    Science.gov (United States)

    1992-04-01

    In fiscal year (FY) 1991, the Accelerator Technology (AT) division continued fulfilling its mission to pursue accelerator science and technology and to develop new accelerator concepts for application to research, defense, energy, industry, and other areas of national interest. This report discusses the following programs: The Ground Test Accelerator Program; APLE Free-Electron Laser Program; Accelerator Transmutation of Waste; JAERI, OMEGA Project, and Intense Neutron Source for Materials Testing; Advanced Free-Electron Laser Initiative; Superconducting Super Collider; The High-Power Microwave Program; (Phi) Factory Collaboration; Neutral Particle Beam Power System Highlights; Accelerator Physics and Special Projects; Magnetic Optics and Beam Diagnostics; Accelerator Design and Engineering; Radio-Frequency Technology; Free-Electron Laser Technology; Accelerator Controls and Automation; Very High-Power Microwave Sources and Effects; and GTA Installation, Commissioning, and Operations.

  7. Accelerator x-ray sources

    CERN Document Server

    Talman, Richard

    2007-01-01

    This first book to cover in-depth the generation of x-rays in particle accelerators focuses on electron beams produced by means of the novel Energy Recovery Linac (ERL) technology. The resulting highly brilliant x-rays are at the centre of this monograph, which continues where other books on the market stop. Written primarily for general, high energy and radiation physicists, the systematic treatment adopted by the work makes it equally suitable as an advanced textbook for young researchers.

  8. Accelerators, Colliders, and Snakes

    Science.gov (United States)

    Courant, Ernest D.

    2003-12-01

    The author traces his involvement in the evolution of particle accelerators over the past 50 years. He participated in building the first billion-volt accelerator, the Brookhaven Cosmotron, which led to the introduction of the "strong-focusing" method that has in turn led to the very large accelerators and colliders of the present day. The problems of acceleration of spin-polarized protons are also addressed, with discussions of depolarizing resonances and "Siberian snakes" as a technique for mitigating these resonances.

  9. Applications of the Strategic Defense Initiative's compact accelerators

    Science.gov (United States)

    Montanarelli, Nick; Lynch, Ted

    1991-12-01

    The Strategic Defense Initiative's (SDI) investment in particle accelerator technology for its directed energy weapons program has produced breakthroughs in the size and power of new accelerators. These accelerators, in turn, have produced spinoffs in several areas: the radio frequency quadrupole linear accelerator (RFQ linac) was recently incorporated into the design of a cancer therapy unit at the Loma Linda University Medical Center, an SDI-sponsored compact induction linear accelerator may replace Cobalt-60 radiation and hazardous ethylene-oxide as a method for sterilizing medical products, and other SDIO-funded accelerators may be used to produce the radioactive isotopes oxygen-15, nitrogen-13, carbon-11, and fluorine-18 for positron emission tomography (PET). Other applications of these accelerators include bomb detection, non-destructive inspection, decomposing toxic substances in contaminated ground water, and eliminating nuclear waste.

  10. The CERN Accelerator School

    CERN Multimedia

    2016-01-01

    Introduction to accelerator physics The CERN Accelerator School: Introduction to Accelerator Physics, which should have taken place in Istanbul, Turkey, later this year has now been relocated to Budapest, Hungary.  Further details regarding the new hotel and dates will be made available as soon as possible on a new Indico site at the end of May.

  11. Accelerators and Dinosaurs

    CERN Multimedia

    Turner, Michael Stanley

    2003-01-01

    Using naturally occuring particles on which to research might have made accelerators become extinct. But in fact, results from astrophysics have made accelerator physics even more important. Not only are accelerators used in hospitals but they are also being used to understand nature's inner workings by searching for Higgs bosons, CP violation, neutrino mass and dark matter (2 pages)

  12. Far field acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Fernow, R.C.

    1995-07-01

    Far fields are propagating electromagnetic waves far from their source, boundary surfaces, and free charges. The general principles governing the acceleration of charged particles by far fields are reviewed. A survey of proposed field configurations is given. The two most important schemes, Inverse Cerenkov acceleration and Inverse free electron laser acceleration, are discussed in detail.

  13. Acceleration: It's Elementary

    Science.gov (United States)

    Willis, Mariam

    2012-01-01

    Acceleration is one tool for providing high-ability students the opportunity to learn something new every day. Some people talk about acceleration as taking a student out of step. In actuality, what one is doing is putting a student in step with the right curriculum. Whole-grade acceleration, also called grade-skipping, usually happens between…

  14. Producing Presences

    OpenAIRE

    Mandagará, Pedro

    2008-01-01

    Resenha de MENDES, Victor K.; ROCHA, João Cezar de Castro (Eds.). Producing Presences: branching out from Gumbrecht’s work. Dartmouth, Massachusetts: University of Massachusetts Dartmouth, 2007. (Adamastor book series, 2)

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

    DEFF Research Database (Denmark)

    Andersen, Jane Lund; Egholm, David Lundbek; Knudsen, Mads Faurschou

    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....... Earth Surface Dynamics 3(4), 463-482, 2015....

  16. The Accelerator Reliability Forum

    CERN Document Server

    Lüdeke, Andreas; Giachino, R

    2014-01-01

    A high reliability is a very important goal for most particle accelerators. The biennial Accelerator Reliability Workshop covers topics related to the design and operation of particle accelerators with a high reliability. In order to optimize the over-all reliability of an accelerator one needs to gather information on the reliability of many different subsystems. While a biennial workshop can serve as a platform for the exchange of such information, the authors aimed to provide a further channel to allow for a more timely communication: the Particle Accelerator Reliability Forum [1]. This contribution will describe the forum and advertise it’s usage in the community.

  17. Industrial Application of Accelerators

    CERN Document Server

    CERN. Geneva

    2017-01-01

    At CERN, we are very familiar with large, high energy particle accelerators. However, in the world outside CERN, there are more than 35000 accelerators which are used for applications ranging from treating cancer, through making better electronics to removing harmful micro-organisms from food and water. These are responsible for around $0.5T of commerce each year. Almost all are less than 20 MeV and most use accelerator types that are somewhat different from what is at CERN. These lectures will describe some of the most common applications, some of the newer applications in development and the accelerator technology used for them. It will also show examples of where technology developed for particle physics is now being studied for these applications. Rob Edgecock is a Professor of Accelerator Science, with a particular interest in the medical applications of accelerators. He works jointly for the STFC Rutherford Appleton Laboratory and the International Institute for Accelerator Applications at the Univer...

  18. Industrial Application of Accelerators

    CERN Document Server

    CERN. Geneva

    2017-01-01

    At CERN, we are very familiar with large, high energy particle accelerators. However, in the world outside CERN, there are more than 35000 accelerators which are used for applications ranging from treating cancer, through making better electronics to removing harmful micro-organisms from food and water. These are responsible for around $0.5T of commerce each year. Almost all are less than 20 MeV and most use accelerator types that are somewhat different from what is at CERN. These lectures will describe some of the most common applications, some of the newer applications in development and the accelerator technology used for them. It will also show examples of where technology developed for particle physics is now being studied for these applications. Rob Edgecock is a Professor of Accelerator Science, with a particular interest in the medical applications of accelerators. He works jointly for the STFC Rutherford Appleton Laboratory and the International Institute for Accelerator Applications at the Uni...

  19. Removal of Radioactive Nuclides by Multi-Functional Microcapsules Enclosing Inorganic Ion-Exchangers and Organic Extractants

    Energy Technology Data Exchange (ETDEWEB)

    Mimura, H.; Akiba, K.; Onodera, Y.

    2002-02-26

    The microcapsules enclosing two kinds of functional materials, inorganic ion-exchangers and organic extractants, were prepared by taking advantage of the high immobilization ability of alginate gel polymer. The fine powders of inorganic ion-exchanger and oil drops of extractant were kneaded with sodium alginate (NaALG) solution and the kneaded sol readily gelled in a salt solution of CaCl2, BaCl2 or HCl to form spherical gel particles. The uptake properties of various nuclides, 137Cs, 85Sr, 60Co, 88Y, 152Eu and 241Am, for thirty-four specimens of microcapsules in the presence of 10-1-10-4 M HNO3 were evaluated by the batch method. The distribution coefficient (Kd) of Cs+ above 103 cm3/g was obtained for the microcapsules enclosing CuFC or AMP. The Kd of Sr2+ around 102 cm3/g was obtained for the microcapsules containing clinoptilolite, antimonic acid, zeolite A, zeolite X or titanic acid. The microcapsules enclosing DEHPA exhibited relatively large Kd values of trivalent metal ions above 103 cm3/g; for example, the Kd values of Cs+, Sr2+, Co2+, Y3+, Eu3+ and Am3+ for a favorable microcapsule (CuFC/clinoptilolite/DEHPA/CaALG) were 1.1x104, 7.5x10, 1.1x10, 1.0x104, 1.4x104, 3.4x103 cm3/g, respectively. The uptake rates of Cs+, Y3+, Eu3+ and Am3+ for this microcapsule were rather fast; the uptake percentage above 90% was obtained after 19 h-shaking and the uptake equilibrium was attained within 1 d. The AMP/CaALG exhibited high uptake ability for Cs+ even after irradiation of 188 kGy, and DEHPA/CaALG microcapsule had similar Kd values of Cs+, Sr2+, Co2+, Y3+, Eu3+ and Am3+ ions before and after irradiation. The microcapsules with various shapes such as spherical, columnar, fibrous and filmy forms were easily prepared by changing the way of dipping kneaded sol into gelling salt solution. The microcapsules enclosing inorganic ion-exchangers and extractants have a potential possibility for the simultaneous removal of various radioactive nuclides from waste solutions.

  20. Acceleration in astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Colgate, S.A.

    1993-12-31

    The origin of cosmic rays and applicable laboratory experiments are discussed. Some of the problems of shock acceleration for the production of cosmic rays are discussed in the context of astrophysical conditions. These are: The presumed unique explanation of the power law spectrum is shown instead to be a universal property of all lossy accelerators; the extraordinary isotropy of cosmic rays and the limited diffusion distances implied by supernova induced shock acceleration requires a more frequent and space-filling source than supernovae; the near perfect adiabaticity of strong hydromagnetic turbulence necessary for reflecting the accelerated particles each doubling in energy roughly 10{sup 5} to {sup 6} scatterings with negligible energy loss seems most unlikely; the evidence for acceleration due to quasi-parallel heliosphere shocks is weak. There is small evidence for the expected strong hydromagnetic turbulence, and instead, only a small number of particles accelerate after only a few shock traversals; the acceleration of electrons in the same collisionless shock that accelerates ions is difficult to reconcile with the theoretical picture of strong hydromagnetic turbulence that reflects the ions. The hydromagnetic turbulence will appear adiabatic to the electrons at their much higher Larmor frequency and so the electrons should not be scattered incoherently as they must be for acceleration. Therefore the electrons must be accelerated by a different mechanism. This is unsatisfactory, because wherever electrons are accelerated these sites, observed in radio emission, may accelerate ions more favorably. The acceleration is coherent provided the reconnection is coherent, in which case the total flux, as for example of collimated radio sources, predicts single charge accelerated energies much greater than observed.

  1. [Evaluating photonuclear activation for clearance of decommissioned medical linear accelerators].

    Science.gov (United States)

    Shida, Koichi; Isobe, Tomonori; Takada, Kenta; Kobayashi, Daisuke; Tadano, Kiichi; Takahashi, Hideki; Seki, Masashi; Yokota, Hiroshi; Sakurai, Hideyuki; Sakae, Takeji

    2011-01-01

    In a linear accelerator (linac) that operates at greater than an accelerating energy of 10 MV, neutrons are generated by a photonuclear reaction and the head section of the linac becomes radioactive. The purpose of this research is to obtain data for ensuring the safety of linac decommissioning and upgrading. The decommissioned linac investigated in this study was a Clinac 2100 C/D (Varian) installed in April 1999. Its total time of use was 2757.7 h (equivalent to 496,386 Gy). The dosage for its last three months of use was 7213.67 Gy. After being allowed to sit for a 7-day cooling period, the apparatus was disassembled and the parts of the gantry head portion were removed. The ambient dose equivalent rates, H*(10), (microSv/h) from the removed parts were measured in air, at a location with low background, by using a gamma ray scintillation survey meter. The target was also analyzed with an HP-Ge semiconductor detector, in order to identify the nuclides responsible for the observed radiation. On day 7 after the last use of the linac, the ambient dose equivalent rates, H*(10), (microSv/h) in air at the surface of all parts, except the target and the beryllium window, were within the limit of normal background radiation. The measured value (microSv/h) for the beryllium window decreased to within the background limit on day 10. The measured value (microSv/h) of the target decreased to about 1.5 times the background on day 19. At a distance of 10 cm, all the parts were within the background limit after the initial 7-day cooling period. In the analysis of the target with the HP-Ge semiconductor detector, peaks at 125, 333, 352, 356, 426, 511, 583, 609, 689, 811, 835, 911, 969, 1091, 1099, 1120, 1173, 1238, 1292, 1333, 1461 and 1764keV were detected on day 23. Seven months after the linac was last used, peaks were detected at 352, 511, 583, 609, 835, 911, 969, 1120, 1173, 1238, 1333, 1461 and 1764 keV. From these results, the natural radioactive nuclides can be assigned

  2. Can the Universe escape eternal acceleration?

    CERN Document Server

    Barrow, John D; Magueijo, J; Barrow, John; Bean, Rachel; Magueijo, Joao

    2000-01-01

    Recent astronomical observations of distant supernovae light-curves suggest that the expansion of the universe has recently begun to accelerate. Acceleration is created by an anti-gravitational repulsive stress, like that produced by a positive cosmological constant, or universal vacuum energy. It creates a rather bleak eschatological picture. An ever-expanding universe's future appears to be increasingly dominated by its constant vacuum energy. A universe doomed to accelerate forever will produce a state of growing uniformity and cosmic loneliness. Structures participating in the cosmological expansion will ultimately leave each others' horizons and information-processing must eventually die out. Here, we examine whether this picture is the only interpretation of the observations. We find that in many well-motivated scenarios the observed spell of vacuum domination is only a transient phenomenon. Soon after acceleration starts, the vacuum energy's anti-gravitational properties are reversed, and a matter-domi...

  3. Repair of overheating linear accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Barkley, Walter; Baldwin, William; Bennett, Gloria; Bitteker, Leo; Borden, Michael; Casados, Jeff; Fitzgerald, Daniel; Gorman, Fred; Johnson, Kenneth; Kurennoy, Sergey; Martinez, Alberto; O’Hara, James; Perez, Edward; Roller, Brandon; Rybarcyk, Lawrence; Stark, Peter; Stockton, Jerry

    2004-01-01

    Los Alamos Neutron Science Center (LANSCE) is a proton accelerator that produces high energy particle beams for experiments. These beams include neutrons and protons for diverse uses including radiography, isotope production, small feature study, lattice vibrations and material science. The Drift Tube Linear Accelerator (DTL) is the first portion of a half mile long linear section of accelerator that raises the beam energy from 750 keV to 100 MeV. In its 31st year of operation (2003), the DTL experienced serious issues. The first problem was the inability to maintain resonant frequency at full power. The second problem was increased occurrences of over-temperature failure of cooling hoses. These shortcomings led to an investigation during the 2003 yearly preventative maintenance shutdown that showed evidence of excessive heating: discolored interior tank walls and coper oxide deposition in the cooling circuits. Since overheating was suspected to be caused by compromised heat transfer, improving that was the focus of the repair effort. Investigations revealed copper oxide flow inhibition and iron oxide scale build up. Acid cleaning was implemented with careful attention to protection of the base metal, selection of components to clean and minimization of exposure times. The effort has been very successful in bringing the accelerator through a complete eight month run cycle allowing an incredible array of scientific experiments to be completed this year (2003-2004). This paper will describe the systems, investigation analysis, repair, return to production and conclusion.

  4. Thomas Jefferson National Accelerator Facility

    Energy Technology Data Exchange (ETDEWEB)

    Grames, Joseph; Higinbotham, Douglas; Montgomery, Hugh

    2010-09-08

    The Thomas Jefferson National Accelerator Facility (Jefferson Lab) in Newport News, Virginia, USA, is one of ten national laboratories under the aegis of the Office of Science of the U.S. Department of Energy (DOE). It is managed and operated by Jefferson Science Associates, LLC. The primary facility at Jefferson Lab is the Continuous Electron Beam Accelerator Facility (CEBAF) as shown in an aerial photograph in Figure 1. Jefferson Lab was created in 1984 as CEBAF and started operations for physics in 1995. The accelerator uses superconducting radio-frequency (srf) techniques to generate high-quality beams of electrons with high-intensity, well-controlled polarization. The technology has enabled ancillary facilities to be created. The CEBAF facility is used by an international user community of more than 1200 physicists for a program of exploration and study of nuclear, hadronic matter, the strong interaction and quantum chromodynamics. Additionally, the exceptional quality of the beams facilitates studies of the fundamental symmetries of nature, which complement those of atomic physics on the one hand and of high-energy particle physics on the other. The facility is in the midst of a project to double the energy of the facility and to enhance and expand its experimental facilities. Studies are also pursued with a Free-Electron Laser produced by an energy-recovering linear accelerator.

  5. Determination of the radionuclide inventory in accelerator waste using calculation and radiochemical analysis

    Energy Technology Data Exchange (ETDEWEB)

    Schumann, D.; Neuhausen, J.; Weinreich, R. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Atchison, F. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)], E-mail: francis.atchison@psi.ch; Kubik, P.; Synal, H.-A. [Paul Scherrer Institut, c/o Institute of Particle Physics, ETH Zuerich, CH-8093 Zurich (Switzerland); Korschinek, G.; Faestermann, Th.; Rugel, G. [Technische Universitaet Muenchen, D-85747 Garching (Germany)

    2007-11-15

    We use a description of the work carried out to determine the radioactive inventory for a redundant beam-dump from the PSI accelerator complex, as an illustration of techniques for the classification and characterisation of accelerator waste and how some difficulties can be circumvented. The work has been carried out using a combination of calculation and sample analysis: The inventory calculation effectively involves a large scale Monte-Carlo transport calculation of a medium-sized spallation facility and for the sample analysis, standard radiochemical analysis techniques have had to be extended to include AMS measurements so as to allow measurement of some of the long half-life, waste disposal relevant, nuclides.

  6. Successful Labeling of \\text{99mTc-MDP Using \\text{99mTc Separated from 99Mo Produced by 100Mo(n,2n)99Mo

    Science.gov (United States)

    Nagai, Yasuki; Hatsukawa, Yuichi; Kin, Tadahiro; Hashimoto, Kazuyuki; Motoishi, Shoji; Konno, Chikara; Ochiai, Kentaro; Takakura, Kosuke; Sato, Yuichi; Kawauchi, Yukimasa; Sato, Norihito; Ohta, Akio; Yamabayashi, Hisamichi; Tanase, Masakazu; Fujisaki, Saburo; Teranaka, Tomoyuki; Takeuchi, Nobuhiro; Igarashi, Takashi

    2011-08-01

    We have for the first time succeeded in separating \\text{99mTc from a MoO3 sample irradiated with accelerator neutrons free from any radioactive impurities and in formulating \\text{99mTc-methylene diphosphonate (\\text{99mTc-MDP). 99Mo, the mother nuclide of \\text{99mTc, was produced by the 100Mo(n,2n)99Mo reaction using about 14 MeV neutrons provided by the 3H(d,n)4He reaction at the Fusion Neutronics Source of Japan Atomic Energy Agency. The \\text{99mTc was separated from 99Mo by sublimation and its radionuclide purity was confirmed to be higher than 99.99% by γ-spectroscopy. The labeling efficiency of \\text{99mTc-MDP was shown to be higher than 99% by thin-layer chromatography. These values exceed the United States Pharmacopeia requirements for a fission product, 99Mo. Consequently, a \\text{99mTc radiopharmaceutical preparation formed by using the mentioned 99Mo can be a promising substitute for the fission product 99Mo, which is currently produced using a highly enriched uranium target in aging research reactors. A longstanding problem to ensure a reliable and constant supply of 99Mo in Japan can be partially mitigated.

  7. Perfil sensorial e aceitação de presuntos crus produzidos por métodos tradicionais e acelerado Sensory profile and acceptance of dry-cured hams produced by traditional and accelerated methods

    Directory of Open Access Journals (Sweden)

    Marcela de Rezende Costa

    2007-03-01

    consumer. Two experimental dry cured hams, produced through fast processing (called CTC 3.5% and 5.0% due the initial added salt content, and four products commercialized in Brazil,: a Spanish Serrano, an Italian one, and two Brazilian ones (Serrano type and Parma type were evaluated. The products differed in terms of the following attributes: CTC 3.5% - the most acid flavored and the lowest intensity of rancid aroma and flavor, redness and juiciness; CTC 5.0% - the highest fibrousness and the lowest intensity and persistence of flavor, and tenderness; Serrano - the highest rancid aroma, redness, intensity and persistence of flavor and the lowest salty flavor; Serrano type - the highest rancid flavor and the lowest sweet flavor; Italian - the highest salty flavor and tenderness; Parma type - the most intense meat flavor, marbling and fat yellowness. All the products were accepted well by the consumer. The Serrano type was the most accepted and Serrano was the lowest accepted by the Brazilian consumers. The CTC products were considered to be good quality, presenting typical characteristics of a dry cured ham, despite the short maturation period.

  8. Niobium films for superconducting accelerating cavities

    Energy Technology Data Exchange (ETDEWEB)

    Benvenuti, C.; Circelli, N.; Hauer, M.

    1984-09-01

    Superconducting accelerating cavities made of Nb-coated copper were produced. Niobium films of a thickness ranging from 1.4 to 4 ..mu..m were deposited onto the inside of 3-GHz cavities and 500-MHz frequency by bias diode sputtering. A maximum accelerating field of 8.6 MV m/sup -1/ was reached without quench which is attributed to the large thermal conductivity of copper at liquid helium temperatures.

  9. Laser ion source for particle accelerators

    CERN Document Server

    Sherwood, T R

    1995-01-01

    There is an interest in accelerating atomic nuclei to produce particle beams for medical therapy, atomic and nuclear physics, inertial confinement fusion and particle physics. Laser Ion Sources, in which ions are extracted from plasma created when a high power density laser beam pulse strikes a solid surface in a vacuum, are not in common use. However, some new developments in which heavy ions have been accelerated show that such sources have the potential to provide the beams required for high-energy accelerator systems.

  10. Exhumation and incision history of the Lahul Himalaya, northern India, based on (U-Th)/He thermochronometry and terrestrial cosmogenic nuclide methods

    Science.gov (United States)

    Adams, Byron; Dietsch, Craig; Owen, Lewis A.; Caffee, Marc W.; Spotila, James; Haneberg, William C.

    2009-06-01

    Low-temperature apatite (U-Th)/He (AHe) thermochronology on vertical transects of leucogranite stocks and 10Be terrestrial cosmogenic nuclide (TCN) surface exposure dating on strath terraces in the Lahul Himalaya provide a first approximation of long-term (10 4-10 6 years) exhumation rates for the High Himalayan Crystalline Series (HHCS) for northern India. The AHe ages show that exhumation of the HHCS in Lahul from shallow crustal levels to the surface was ~ 1-2 mm/a and occurred during the past ~ 2.5 Ma. Bedrock exhumation in Lahul fits into a regional pattern in the HHCS of low-temperature thermochronometers yielding Plio-Pleistocene ages. Surface exposure ages of strath terraces along the Chandra River range from ~ 3.5 to 0.2 ka. Two sites along the Chandra River show a correlation between TCN age and height above the river level yielding maximum incision rates of 12 and 5.5 mm/a. Comparison of our AHe and surface exposure ages from Lahul with thermochronometry data from the fastest uplifting region at the western end of the Himalaya, the Nanga Parbat syntaxis, illustrates that there are contrasting regions in the High Himalaya where longer term (10 5-10 7 years) erosion and exhumation of bedrock substantially differ even though Holocene rates of fluvial incision are comparable. These data imply that the orogen's indenting corners are regions where focused denudation has been stable since the mid-Pliocene. However, away from these localized areas where there is a potent coupling of tectonic and surface processes that produce rapid uplift and denudation, Plio-Pleistocene erosion and exhumation can be characterized by disequilibrium, where longer term rates are relatively slower and shorter term fluvial erosion is highly variable over time and distance. The surface exposure age data reflect differential incision along the length of the Chandra River over millennial time frames, illustrate the variances that are possible in Himalayan river incision, and highlight

  11. Cirques have growth spurts during deglacial and interglacial periods: Evidence from 10Be and 26Al nuclide inventories in the central and eastern Pyrenees

    Science.gov (United States)

    Crest, Y.; Delmas, M.; Braucher, R.; Gunnell, Y.; Calvet, M.

    2017-02-01

    Cirques are emblematic landforms of alpine landscapes. The statistical distribution of cirque-floor elevations is used to infer glacial equilibrium-line altitude, and the age of their frontal moraines for reconstructing glacial chronologies. Very few studies, however, have sought to measure cirque-floor and supraglacial ridgetop bedrock downwearing rates in order to confront these denudation estimates with theoretical models of Quaternary mountain landscape evolution. Here we use 10Be nuclide samples (n = 36) from moraines, bedrock steps, and supraglacial ridgetops among a population of cirques in the east-central Pyrenees in order to quantify denudation in the landscape and detect whether the mountain topography bears any relevance to the glacial buzzsaw hypothesis. Minimum exposure ages (MEAs) obtained for a succession of moraines spanning the Oldest Dryas to the Holocene produced a deglaciation chronology for three different Pyrenean ranges: Maladeta, Bassiès, and Carlit. Based on a series of corrections, calibrations, and chronostratigraphic tuning procedures, MEAs on ice-polished bedrock exposures were further used to model denudation depths at nested timescales during the Würm, the Younger Dryas, and the Holocene. Results show that subglacial cirque-floor denudation was lower during glacial periods (Würm: 10 mm/ka) than during deglacial and interglacial periods (tens to hundreds of mm/ka). The relative inefficiency of glacial denudation in the cirque zone during the Würm would have resulted from (i) cold-based and/or (ii) low-gradient glaciers situated in the upper reaches of the icefield; and/or from (iii) glacier-load starvation because of arrested clast supply from supraglacial rockslopes situated in the permafrost zone. Denudation peaked during the Younger Dryas and Holocene glacial advances, a time when cirque glaciers became steeper, warmer-based, and when frost cracking weakened supraglacial ridgetops, thus enhancing subglacial erosion by providing

  12. Nuclide, metal and non metal levels in percolated water from soils fertilized with phosphogypsum

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Camilla Bof; Knupp, Eliana Aparecida Nonato; Palmieri, Helena E.L.; Jacomino, Vanusa Maria Feliciano, E-mail: cgbs@cdtn.b [Nuclear Technology Development Center (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Taddei, Maria Helena; Ciqueira, Maria Celia [Pocos de Caldas Lab., (LAPOC/CNEN), Pocos de Caldas, MG (Brazil)

    2009-07-01

    Systematic generation of residues is more and more worrying in today.s world; adequate storage and reutilization are of great importance. Since generation of residues has become impossible to avoid, the possibility of reuse must be studied and researched. An example of these residues is phosphogypsum, which is generated in phosphoric acid production at the rate of around 4.8 tons for each ton of phosphoric acid produced. Many studies seek to reuse phosphogypsum in agriculture as a source of calcium and sulfur, potassium or aluminum, especially in soils from Brazil's cerrado regions. Though phosphogypsum is mainly composed of dehydrated calcium sulfate, it can have high levels of heavy metals, non metals (As and Se), fluorides and natural radionuclides. Thus, its uncontrolled use as a soil conditioner can lead to contamination of underground water. (author)

  13. Efficient and Accurate Calculation of Burnup Problems with Short-Lived Nuclides by a Krylov Subspace Method with the Newton Divided Difference

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yoon Hee; Cho, Nam Zin [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2010-05-15

    Nowadays lattice physics codes tend to utilize a detailed burnup chain including short-lived nuclides in order to perform more accurate burnup calculations. But, since production codes, for example, ORIGEN2, take account of nuclides which have relatively long half-life, it is inappropriate for such detailed burnup chain calculation. To enhance that drawback, many matrix exponential calculation methods have been developed. Recently, a Krylov subspace method with the PADE approximation was used. In this paper, a Krylov subspace method based on spectral decomposition property of the matrix function theory with the Newton divided difference (NDD) is introduced. It is tested with a sample problem and compared with simple Taylor expansion method

  14. 89Zr, a Radiometal Nuclide with High Potential for Molecular Imaging with PET: Chemistry, Applications and Remaining Challenges

    Directory of Open Access Journals (Sweden)

    Ralf Schirrmacher

    2013-06-01

    Full Text Available Molecular imaging—and especially Positron Emission Tomography (PET—is of increasing importance for the diagnosis of various diseases and thus is experiencing increasing dissemination. Consequently, there is a growing demand for appropriate PET tracers which allow for a specific accumulation in the target structure as well as its visualization and exhibit decay characteristics matching their in vivo pharmacokinetics. To meet this demand, the development of new targeting vectors as well as the use of uncommon radionuclides becomes increasingly important. Uncommon nuclides in this regard enable the utilization of various selectively accumulating bioactive molecules such as peptides, antibodies, their fragments, other proteins and artificial structures for PET imaging in personalized medicine. Among these radionuclides, 89Zr (t1/2 = 3.27 days and mean Eβ+ = 0.389 MeV has attracted increasing attention within the last years due to its favorably long half-life, which enables imaging at late time-points, being especially favorable in case of slowly-accumulating targeting vectors. This review outlines the recent developments in the field of 89Zr-labeled bioactive molecules, their potential and application in PET imaging and beyond, as well as remaining challenges.

  15. Technical support for GEIS: radioactive waste isolation in geologic formations. Volume 21. Ground water movement and nuclide transport

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-04-01

    This volume, TM-36/21 Ground Water Movement and Nuclide Transport, is one of a 23-volume series, ''Technical Support for GEIS: Radioactive Waste Isolation in Geologic Formations, Y/OWI/TM-36'' which supplements a ''Contribution to Draft Generic Environmental Impact Statement on Commercial Waste Management: Radioactive Waste Isolation in Geologic Formations, Y/OWI/TM-44.'' The series provides a more complete technical basis for the preconceptual designs, resource requirements, and environmental source terms associated with isolating commercial LWR wastes in underground repositories in salt, granite, shale and basalt. Wastes are considered from three fuel cycles: uranium and plutonium recycling of spent fuel and uranium-only recycling. The studies presented in this volume consider the effect of the construction of the repository and the consequent heat generation on the ground water movement. Additionally, the source concentrations and leach rates of selected radionuclides were studied in relation to the estimated ground water inflow rates. Studies were also performed to evaluate the long term migration of radionuclides as affected by the ground water flow. In all these studies, three geologic environments are considered; granite, shale and basalt.

  16. An octahedral deformation with six alpha particles at the Z = 12 system, Mg nuclides: Third nucleons, Alpharons

    CERN Document Server

    Moon, Chang-Bum

    2016-01-01

    We suggest that the emergence of a large deformation in the magnesium, Mg, nuclides, especially at the Z = 12, N = 12, should be associated with an octahedral deformed shape. Within the framework of molecular geometrical symmetry, we find a possibility that the Z = 12, N = 12 system would form an octahedral structure consisting of six points of alpha(4He) particles, yielding the ground collectivity. With this point of view, we draw the following serial molecular structures; the Z = 10, N = 10, 20Ne, corresponds to a hexahedral, the Z = 8, N = 8, 16O, does to a tetrahedral, and the Z = 6, N = 6, 12C, does to a trigonal symmetry. Moreover, the Z = 2, N = 2, 4He(alpha), fits into a tetrahedral symmetry with four points of nucleons; two protons and two neutrons. The enhanced deformation at Z = 12 with N > 20 would be explained by a deformed shape related to an Ethene(Ethylene)-like skeleton with six alpha particles. The deformation at Z = 10, with N = 10 and 12, can be interpreted as being attributed to a hexahed...

  17. Radioactivity of Natural Nuclides (40K, 238U, 232Th, 226Ra in Coals from Eastern Yunnan, China

    Directory of Open Access Journals (Sweden)

    Xin Wang

    2015-09-01

    Full Text Available The naturally occurring primordial radionuclides in coals might exhibit high radioactivity, and can be exported to the surrounding environment during coal combustion. In this study, nine coal samples were collected from eastern Yunnan coal deposits, China, aiming at characterizing the overall radioactivity of some typical nuclides (i.e., 40K, 238U, 232Th, 226Ra and assessing their ecological impact. The mean activity concentrations of 238U, 232Th, 40K and 226Ra are 63.86 (17.70–92.30 Bq· kg-1, 23.76 (11.10–37.10 Bq· kg-1, 96.84 (30.60–229.30 Bq· kg-1 and 28.09 Bq·kg-1 (3.10–61.80 Bq·kg-1, respectively. Both 238U and 232Th have high correlations with ash yield of coals, suggesting their inorganic origins. The overall environmental effect of natural radionuclides in studied coals is considered to be negligible, as assessed by related indexes (i.e., radium equivalent activity, air-adsorbed dose rate, annual effective dose, and external hazard index. However, the absorbed dose rates values are higher than the average value of global primordial radiation and the Chinese natural gamma radiation dose rate.

  18. G4MoNA - A Geant4 Simulation for unbound nuclides detected with MoNA/LISA

    Science.gov (United States)

    Gueye, Paul; Freeman, Jessica; Frank, Nathan; MoNA Collaboration

    2017-01-01

    The MoNA Collaboration has conducted a plethora of experiments to study unbound nuclei near the neutron dripline using the invariant mass technique since 2005. These experiments used a variety of secondary beams from the Coupled Cyclotron Facility of the National Superconducting Cyclotron Laboratory. The experimental setup consists of a large gap superconducting Sweeper magnet for charged fragments separation and the MoNA/LISA neutron detector arrays for neutron detection. Recently, a multi-layered Si/Be segmented target consisting of three 700 mg/cm2 thick 9Be slabs and four 140 μ m Si detectors were added to the setup. This target improves the resolution of the reconstructed decay energy spectra of the unbound nuclides. The Geant4 Monte Carlo simulation toolkit was used to develop a complete realistic model of the setup including a new class to treat the decay of unbound nuclei, the Si/Be segmented target, the MoNA/LISA and the charged fragments detector systems. Comparison between simulated and experimental data will be presented. DoENNSA - DE-NA0000979.

  19. A New Paradigm for Flare Particle Acceleration

    Science.gov (United States)

    Guidoni, Silvina E.; Karpen, Judith T.; DeVore, C. Richard

    2017-08-01

    The mechanism that accelerates particles to the energies required to produce the observed high-energy impulsive emission and its spectra in solar flares is not well understood. Here, we propose a first-principle-based model of particle acceleration that produces energy spectra that closely resemble those derived from hard X-ray observations. Our mechanism uses contracting magnetic islands formed during fast reconnection in solar flares to accelerate electrons, as first proposed by Drake et al. (2006) for kinetic-scale plasmoids. We apply these ideas to MHD-scale islands formed during fast reconnection in a simulated eruptive flare. A simple analytic model based on the particles’ adiabatic invariants is used to calculate the energy gain of particles orbiting field lines in our ultrahigh-resolution, 2.5D, MHD numerical simulation of a solar eruption (flare + coronal mass ejection). Then, we analytically model electrons visiting multiple contracting islands to account for the observed high-energy flare emission. Our acceleration mechanism inherently produces sporadic emission because island formation is intermittent. Moreover, a large number of particles could be accelerated in each macroscopic island, which may explain the inferred rates of energetic-electron production in flares. We conclude that island contraction in the flare current sheet is a promising candidate for electron acceleration in solar eruptions. This work was supported in part by the NASA LWS and H-SR programs..

  20. Accelerator reliability workshop

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, L.; Duru, Ph.; Koch, J.M.; Revol, J.L.; Van Vaerenbergh, P.; Volpe, A.M.; Clugnet, K.; Dely, A.; Goodhew, D

    2002-07-01

    About 80 experts attended this workshop, which brought together all accelerator communities: accelerator driven systems, X-ray sources, medical and industrial accelerators, spallation sources projects (American and European), nuclear physics, etc. With newly proposed accelerator applications such as nuclear waste transmutation, replacement of nuclear power plants and others. Reliability has now become a number one priority for accelerator designers. Every part of an accelerator facility from cryogenic systems to data storage via RF systems are concerned by reliability. This aspect is now taken into account in the design/budget phase, especially for projects whose goal is to reach no more than 10 interruptions per year. This document gathers the slides but not the proceedings of the workshop.

  1. Accelerator and radiation physics

    CERN Document Server

    Basu, Samita; Nandy, Maitreyee

    2013-01-01

    "Accelerator and radiation physics" encompasses radiation shielding design and strategies for hadron therapy accelerators, neutron facilities and laser based accelerators. A fascinating article describes detailed transport theory and its application to radiation transport. Detailed information on planning and design of a very high energy proton accelerator can be obtained from the article on radiological safety of J-PARC. Besides safety for proton accelerators, the book provides information on radiological safety issues for electron synchrotron and prevention and preparedness for radiological emergencies. Different methods for neutron dosimetry including LET based monitoring, time of flight spectrometry, track detectors are documented alongwith newly measured experimental data on radiation interaction with dyes, polymers, bones and other materials. Design of deuteron accelerator, shielding in beam line hutches in synchrotron and 14 MeV neutron generator, various radiation detection methods, their characteriza...

  2. The US Muon Accelerator Program

    Energy Technology Data Exchange (ETDEWEB)

    Torun, Y.; /IIT, Chicago; Kirk, H.; /Brookhaven; Bross, A.; Geer, Steve; Shiltsev, Vladimir; /Fermilab; Zisman, M.; /LBL, Berkeley

    2010-05-01

    An accelerator complex that can produce ultra-intense beams of muons presents many opportunities to explore new physics. A facility of this type is unique in that, in a relatively straightforward way, it can present a physics program that can be staged and thus move forward incrementally, addressing exciting new physics at each step. At the request of the US Department of Energy's Office of High Energy Physics, the Neutrino Factory and Muon Collider Collaboration (NFMCC) and the Fermilab Muon Collider Task Force (MCTF) have recently submitted a proposal to create a Muon Accelerator Program that will have, as a primary goal, to deliver a Design Feasibility Study for an energy-frontier Muon Collider by the end of a 7 year R&D program. This paper presents a description of a Muon Collider facility and gives an overview of the proposal.

  3. The US Muon Accelerator Program

    Energy Technology Data Exchange (ETDEWEB)

    Torun, Y.; /IIT, Chicago; Kirk, H.; /Brookhaven; Bross, A.; Geer, Steve; Shiltsev, Vladimir; /Fermilab; Zisman, M.; /LBL, Berkeley

    2010-05-01

    An accelerator complex that can produce ultra-intense beams of muons presents many opportunities to explore new physics. A facility of this type is unique in that, in a relatively straightforward way, it can present a physics program that can be staged and thus move forward incrementally, addressing exciting new physics at each step. At the request of the US Department of Energy's Office of High Energy Physics, the Neutrino Factory and Muon Collider Collaboration (NFMCC) and the Fermilab Muon Collider Task Force (MCTF) have recently submitted a proposal to create a Muon Accelerator Program that will have, as a primary goal, to deliver a Design Feasibility Study for an energy-frontier Muon Collider by the end of a 7 year R&D program. This paper presents a description of a Muon Collider facility and gives an overview of the proposal.

  4. Hardware-Accelerated Simulated Radiography

    Energy Technology Data Exchange (ETDEWEB)

    Laney, D; Callahan, S; Max, N; Silva, C; Langer, S; Frank, R

    2005-08-04

    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 solutions to the radiative transport equation for X-rays. The hardware accelerated solutions are accurate enough to enable scientists to explore the experimental design space with greater efficiency than the methods currently in use. An unsorted hexahedron projection algorithm is presented for curvilinear hexahedral meshes 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.

  5. Power Converters for Accelerators

    CERN Document Server

    Visintini, R

    2015-01-01

    Particle accelerators use a great variety of power converters for energizing their sub-systems; while the total number of power converters usually depends on the size of the accelerator or combination of accelerators (including the experimental setup), the characteristics of power converters depend on their loads and on the particle physics requirements: this paper aims to provide an overview of the magnet power converters in use in several facilities worldwide.

  6. Miniaturization Techniques for Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, James E.

    2003-05-27

    The possibility of laser driven accelerators [1] suggests the need for new structures based on micromachining and integrated circuit technology because of the comparable scales. Thus, we are exploring fully integrated structures including sources, optics (for both light and particle) and acceleration in a common format--an accelerator-on-chip (AOC). Tests suggest a number of preferred materials and techniques but no technical or fundamental roadblocks at scales of order 1 {micro}m or larger.

  7. Boiling water reactors with Uranium-Plutonium mixed oxide fuel. Report 1: Accuracy of the nuclide concentrations calculated by CASMO-4

    Energy Technology Data Exchange (ETDEWEB)

    Demaziere, C. [CEA Centre d' Etudes de Cadarache, Saint-Paul-lez-Durance (France). Direction des Reacteurs Nucleaires

    1999-07-01

    This report is a part of the project titled 'Boiling Water Reactors With Uranium-Plutonium Mixed Oxide (MOx) Fuel'. The aim of this study is to model the impact of a core loading pattern containing MOx bundles upon the main characteristics of a BWR (reactivity coefficients, stability, etc.). The tools that are available to perform a modeling in the Department of Reactor Physics in Chalmers are CASMO-4/TABLES-3/SIMULATE-3 from Studsvik of America. These CMS (Core Management System) programs have been extensively compared with both measurements and reference codes. Nevertheless some data are proprietary in particular the comparison of the calculated nuclide concentrations versus experiments (because of the cost of this kind of experimental study). This is why this report describes such a comparative investigation carried out with a General Electric 7x7 BWR bundle. Unfortunately, since some core history parameters were unknown, a lot of hypotheses have been adopted. This invokes sometimes a significant discrepancy in the results without being able to determine the origin of the differences between calculations and experiments. Yet one can assess that, except for four nuclides - Plutonium-238, Curium-243, Curium-244 and Cesium-135 - for which the approximate power history (history effect) can be invoked, the accuracy of the calculated nuclide concentrations is rather good if one takes the numerous approximations into account.

  8. RESEARCH METHODS FOR EVALUATION ABSORBING AND ACCUMULATING NUCLIDES OF PLANT%植物吸收和富集核素的研究方法

    Institute of Scientific and Technical Information of China (English)

    唐永金; 罗学刚

    2011-01-01

    本文在把植物吸收和富集核素的研究分为监测性研究、机理性研究、修复性研究和胁迫性研究的基础上,从核素的选择与处理、植物的选择、试验方法、评价方法几个方面,归纳讨论了植物吸收和富集核素的研究方法,以期为核素的植物生态修复研究提供一些参考。%This paper reviewed the recent studies on plants absorb and accumulation of nuclides and devided the studies to several aspects such as monitoring,mechanism restoration,and stressing based on their purpose.The paper also summaried the methods for selection and treatment of nuclides,plants preparation,nuclides test and evaluation.

  9. Development of a method to determine the nuclide inventory in bituminized waste packages; Entwicklung eines Verfahrens zur Bestimmung des Nuklidinventars in bituminierten Abfallgebinden

    Energy Technology Data Exchange (ETDEWEB)

    Mesalic, E.; Kortman, F.; Lierse von Gostomski, C. [Technische Univ. Muenchen, Garching (Germany). Zentrale Technisch-Wissenschaftliche Betriebseinheit Radiochemie Muenchen (RCM)

    2014-01-15

    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.)

  10. FFAGS for rapid acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Carol J. Johnstone and Shane Koscielniak

    2002-09-30

    When large transverse and longitudinal emittances are to be transported through a circular machine, extremely rapid acceleration holds the advantage that the beam becomes immune to nonlinear resonances because there is insufficient time for amplitudes to build up. Uncooled muon beams exhibit large emittances and require fast acceleration to avoid decay losses and would benefit from this style of acceleration. The approach here employs a fixed-field alternating gradient or FFAG magnet structure and a fixed frequency acceleration system. Acceptance is enhanced by the use only of linear lattice elements, and fixed-frequency rf enables the use of cavities with large shunt resistance and quality factor.

  11. FFAGS FOR MUON ACCELERATION.

    Energy Technology Data Exchange (ETDEWEB)

    BERG,J.S.KAHN,S.PALMER,R.TRBOJEVIC,D.JOHNSTONE,C.KEIL,Y.OGITSU,T.OHMORI,C.SESSLER,A.KOSCIELNIAK,S.

    2003-06-26

    Due to their finite lifetime, muons must be accelerated very rapidly. It is challenging to make the magnets ramp fast enough to accelerate in a synchrotron, and accelerating in a linac is very expensive. One can use a recirculating accelerator (like CEBAF), but one needs a different arc for each turn, and this limits the number of turns one can use to accelerate, and therefore requires significant amounts of RF to achieve the desired energy gain. An alternative method for muon acceleration is using a fixed field alternating gradient (FFAG) accelerator. Such an accelerator has a very large energy acceptance (a factor of two or three), allowing one to use the same arc with a magnetic field that is constant over time. Thus, one can in principle make as many turns as one can tolerate due to muon decay, therefore reducing the RF cost without increasing the arc cost. This paper reviews the current status of research into the design of FFAGs for muon acceleration. Several current designs are described and compared. General design considerations are also discussed.

  12. High Gradient Accelerator Research

    Energy Technology Data Exchange (ETDEWEB)

    Temkin, Richard [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Dept. of Physics. Plasma Science and Fusion Center

    2016-07-12

    The goal of the MIT program of research on high gradient acceleration is the development of advanced acceleration concepts that lead to a practical and affordable next generation linear collider at the TeV energy level. Other applications, which are more near-term, include accelerators for materials processing; medicine; defense; mining; security; and inspection. The specific goals of the MIT program are: • Pioneering theoretical research on advanced structures for high gradient acceleration, including photonic structures and metamaterial structures; evaluation of the wakefields in these advanced structures • Experimental research to demonstrate the properties of advanced structures both in low-power microwave cold test and high-power, high-gradient test at megawatt power levels • Experimental research on microwave breakdown at high gradient including studies of breakdown phenomena induced by RF electric fields and RF magnetic fields; development of new diagnostics of the breakdown process • Theoretical research on the physics and engineering features of RF vacuum breakdown • Maintaining and improving the Haimson / MIT 17 GHz accelerator, the highest frequency operational accelerator in the world, a unique facility for accelerator research • Providing the Haimson / MIT 17 GHz accelerator facility as a facility for outside users • Active participation in the US DOE program of High Gradient Collaboration, including joint work with SLAC and with Los Alamos National Laboratory; participation of MIT students in research at the national laboratories • Training the next generation of Ph. D. students in the field of accelerator physics.

  13. Synergy of decay spectroscopy and mass spectrometry for the study of exotic nuclides

    CERN Document Server

    Stanja, Juliane

    With only two ingredients, atomic nuclei exhibit a rich structure depending on the ordering of the different proton- and neutron-occupied states. This ordering can give rise to excited states with exceptionally long half-lives, also known as isomers, especially near shell closures. On-line mass spectrometry can often be compromised by the existence of such states that may even be produced in higher proportion than the ground state. This thesis presents the first results obtained from a nuclear spectroscopy setup coupled with the high-resolution Penning-trap mass spectrometer ISOLTRAP, at CERN’s radioactive ion beam facility ISOLDE. The isomerism in the neutron-deficient thallium isotopes was investigated. The data on $^{184,190,193−195}$Tl allow an improvement of existing mass values as well as a mass-spin- state assignment in $^{ 190,193,194}$Tl. Due to the presence of the ground and isomeric state for $^{ 194}$Tl the excitation energy of the latter was determined for the first time experimentally. Syste...

  14. Synergy of decay spectroscopy and mass spectrometry for the study of exotic nuclides

    Energy Technology Data Exchange (ETDEWEB)

    Stanja, Juliane

    2013-04-12

    With only two ingredients, atomic nuclei exhibit a rich structure depending on the ordering of the different proton- and neutron-occupied states. This ordering can give rise to excited states with exceptionally long half-lives, also known as isomers, especially near shell closures. On-line mass spectrometry can often be compromised by the existence of such states that may even be produced in higher proportion than the ground state. This thesis presents the first results obtained from a nuclear spectroscopy setup coupled with the high-resolution Penning-trap mass spectrometer ISOLTRAP, at CERN's radioactive ion beam facility ISOLDE. The isomerism in the neutron-deficient thallium isotopes was investigated. The data on {sup 184,190,193-195}Tl allow an improvement of existing mass values as well as a mass-spin-state assignment in {sup 190,193,194}Tl. Due to the presence of the ground and isomeric state for {sup 194}Tl the excitation energy of the latter was determined for the first time experimentally. Systematic trends in the vicinity of the Z = 82 shell closure have been discussed.

  15. Topics in radiation at accelerators: Radiation physics for personnel and environmental protection

    Energy Technology Data Exchange (ETDEWEB)

    Cossairt, J.D.

    1996-10-01

    In the first chapter, terminology, physical and radiological quantities, and units of measurement used to describe the properties of accelerator radiation fields are reviewed. The general considerations of primary radiation fields pertinent to accelerators are discussed. The primary radiation fields produced by electron beams are described qualitatively and quantitatively. In the same manner the primary radiation fields produced by proton and ion beams are described. Subsequent chapters describe: shielding of electrons and photons at accelerators; shielding of proton and ion accelerators; low energy prompt radiation phenomena; induced radioactivity at accelerators; topics in radiation protection instrumentation at accelerators; and accelerator radiation protection program elements.

  16. Induced radioactivity in and around high-energy particle accelerators.

    Science.gov (United States)

    Vincke, Helmut; Theis, Chris; Roesler, Stefan

    2011-07-01

    Particle accelerators and their surroundings are locations of residual radioactivity production that is induced by the interaction of high-energy particles with matter. This paper gives an overview of the principles of activation caused at proton accelerators, which are the main machines operated at Conseil Européen pour la Recherche Nucléaire. It describes the parameters defining radio-nuclide production caused by beam losses. The second part of the paper concentrates on the analytic calculation of activation and the Monte Carlo approach as it is implemented in the FLUKA code. Techniques used to obtain, on the one hand, estimates of radioactivity in Becquerel and, on the other hand, residual dose rates caused by the activated material are discussed. The last part of the paper focuses on experiments that allow for benchmarking FLUKA activation calculations and on simulations used to predict activation in and around high-energy proton machines. In that respect, the paper addresses the residual dose rate that will be induced by proton-proton collisions at an energy of two times 7 TeV in and around the Compact Muon Solenoid (CMS) detector. Besides activation of solid materials, the air activation expected in the CMS cavern caused by this beam operation is also discussed.

  17. Deuteron and neutron induced activation in the Eveda accelerator materials: implications for the accelerator maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, M.; Sanz, J.; Garcia, N.; Cabellos, O. [Madrid Univ. Politecnica, C/ Jose Gutierrez Abascal, lnstituto de Fusion Nuclear (Spain); Sauvan, R. [Universidad Nacional de Educacion a Distancia (UNED), Madrid (Spain); Moreno, C.; Sedano, L.A. [CIEMAT-Centro de Investigaciones Energeticas Medioambientales y Tecnologicas, Association Euratom-CIEMAT, Madrid (Spain)

    2007-07-01

    Full text of publication follows: The IFMIF (International Fusion Materials Irradiation Facility) is an accelerator-based DLi neutron source designed to test fusion reactor candidate materials for high fluence neutrons. Before deciding IFMIF construction, an engineering design and associated experimental data acquisition, defined as EVEDA, has been proposed. Along the EVEDA accelerator, deuteron beam losses collide with the accelerator materials, producing activation and consequent radiations responsible of dose. Calculation of the dose rates in the EVEDA accelerator room is necessary in order to analyze the feasibility for manual maintenance. Dose rates due to the activation produced by the deuteron beam losses interaction with the accelerator materials, will be calculated with the ACAB activation code, using EAF2007 library for deuteron activation cross-sections. Also, dose rates from the activation induced by the neutron source produced by the interaction of deuteron beam losses with the accelerator materials and the deuterium implanted in the structural lattice, will be calculated with the SRIM2006, TMAP7, DROSG2000/NEUYIE, MCNPX and ACAB codes. All calculations will be done for the EVEDA accelerator with the room temperature DTL structure, which is based on copper cavities for the DTL. Some calculations will be done for the superconducting DTL structure, based on niobium cavities for the DTL working at cryogenic temperature. Final analysis will show the dominant mechanisms and major radionuclides contributing to the surface dose rates. (authors)

  18. Technology development for high power induction accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Birx, D.L.; Reginato, L.L.

    1985-06-11

    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.

  19. {sup 90}Nb - a potential PET nuclide. Production and labeling of monoclonal antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Radchenko, V.; Roesch, F. [Mainz Univ. (Germany). Inst. of Nuclear Chemistry; Hauser, H.; Eisenhut, M. [German Cancer Research Center, Heidelberg (Germany). Radiopharmaceutical Chemistry; Vugts, D.J.; Dongen, G.A.M.S. van [VU University Medical Center, Amsterdam (Netherlands). Dept. of Nuclear Medicine and PET Research; VU University Medical Center, Amsterdam (Netherlands). Dept. of Otolaryngology/Head and Neck Surgery

    2012-07-01

    Fast progressing immuno-PET gives reasons to develop new potential medium-long and long-lived radioisotopes. One of the promising candidates is {sup 90}Nb. It has a half-life of 14.6 h, which allows visualizing and quantifying processes with medium and slow kinetics, such as tumor accumulation of antibodies and antibodies fragments or polymers and other nanoparticles. {sup 90}Nb exhibits a high positron branching of 53% and an optimal energy of {beta}{sup +} emission of E{sub mean} = 0.35 MeV only. Consequently, efficient radionuclide production routes and Nb{sup V} labeling techniques are required. {sup 90}Nb was produced by the {sup 90}Zr(p,n){sup 90}Nb nuclear reaction on natural zirconium targets. No-carrier-added (n.c.a.) {sup 90}Nb was separated from the zirconium target via a multi-step separation procedure including extraction steps and ion-exchange chromatography. Protein labeling was exemplified using the bifunctional chelator desferrioxamine attached to the monoclonal antibody rituximab. Desferrioxamine was coupled to rituximab via two different routes, by the use of N-succinyl-desferrioxamine (N-suc-Df) and by means of the bifunctional derivative p-isothiocyanatobenzyl-desferrioxamine B (Df-Bz-NCS), respectively. Following antibody modification, labeling with {sup 90}Nb was performed in HEPES buffer at pH 7 at room temperature. In vitro stability of the radiolabeled conjugates was tested in saline buffer at room temperature and in fetal calf serum (FCS) at 37 C. The selected production route led to a high yield of 145 {+-} 10 MBq/{mu}A h of {sup 90}Nb with high radioisotopic purity of > 97%. This yield may allow for large scale production of about 10 GBq {sup 90}Nb. The separation procedure resulted in 76-81% yield. The Zr/{sup 90}Nb decontamination factor reaches 10{sup 7}. Subsequent radiolabeling of the two different conjugates with {sup 90}Nb gave high yields; after one hour incubation at room temperature, more than 90% of {sup 90}Nb-Df-mAb was

  20. Asia honours accelerator physicists

    CERN Multimedia

    2010-01-01

    "Steve Meyers of Cern and Jie Wei of Beijing's Tsinghua University are the first recipients of a new prize for particle physics. The pair were honoured for their contributions to numerous particle-accelerator projects - including Cern's Large Hadron Collider - by the Asian Committee for Future Accelerators (ACFA)..." (1 paragraph)

  1. COLLECTIVE-FIELD ACCELERATION

    Energy Technology Data Exchange (ETDEWEB)

    Sessler, Andrew M.

    1969-07-04

    Diverse methods proposed for the acceleration of particles by means of collective fields are reviewed. A survey is made of the various currently active experimental programs devoted to investigating collective acceleration, and the present status of the research is briefly noted.

  2. KEK digital accelerator

    Science.gov (United States)

    Iwashita, T.; Adachi, T.; Takayama, K.; Leo, K. W.; Arai, T.; Arakida, Y.; Hashimoto, M.; Kadokura, E.; Kawai, M.; Kawakubo, T.; Kubo, Tomio; Koyama, K.; Nakanishi, H.; Okazaki, K.; Okamura, K.; Someya, H.; Takagi, A.; Tokuchi, A.; Wake, M.

    2011-07-01

    The High Energy Accelerator Research Organization KEK digital accelerator (KEK-DA) is a renovation of the KEK 500 MeV booster proton synchrotron, which was shut down in 2006. The existing 40 MeV drift tube linac and rf cavities have been replaced by an electron cyclotron resonance (ECR) ion source embedded in a 200 kV high-voltage terminal and induction acceleration cells, respectively. A DA is, in principle, capable of accelerating any species of ion in all possible charge states. The KEK-DA is characterized by specific accelerator components such as a permanent magnet X-band ECR ion source, a low-energy transport line, an electrostatic injection kicker, an extraction septum magnet operated in air, combined-function main magnets, and an induction acceleration system. The induction acceleration method, integrating modern pulse power technology and state-of-art digital control, is crucial for the rapid-cycle KEK-DA. The key issues of beam dynamics associated with low-energy injection of heavy ions are beam loss caused by electron capture and stripping as results of the interaction with residual gas molecules and the closed orbit distortion resulting from relatively high remanent fields in the bending magnets. Attractive applications of this accelerator in materials and biological sciences are discussed.

  3. KEK digital accelerator

    Directory of Open Access Journals (Sweden)

    T. Iwashita

    2011-07-01

    Full Text Available The High Energy Accelerator Research Organization KEK digital accelerator (KEK-DA is a renovation of the KEK 500 MeV booster proton synchrotron, which was shut down in 2006. The existing 40 MeV drift tube linac and rf cavities have been replaced by an electron cyclotron resonance (ECR ion source embedded in a 200 kV high-voltage terminal and induction acceleration cells, respectively. A DA is, in principle, capable of accelerating any species of ion in all possible charge states. The KEK-DA is characterized by specific accelerator components such as a permanent magnet X-band ECR ion source, a low-energy transport line, an electrostatic injection kicker, an extraction septum magnet operated in air, combined-function main magnets, and an induction acceleration system. The induction acceleration method, integrating modern pulse power technology and state-of-art digital control, is crucial for the rapid-cycle KEK-DA. The key issues of beam dynamics associated with low-energy injection of heavy ions are beam loss caused by electron capture and stripping as results of the interaction with residual gas molecules and the closed orbit distortion resulting from relatively high remanent fields in the bending magnets. Attractive applications of this accelerator in materials and biological sciences are discussed.

  4. Accelerators, Beams And Physical Review Special Topics - Accelerators And Beams

    Energy Technology Data Exchange (ETDEWEB)

    Siemann, R.H.; /SLAC

    2011-10-24

    Accelerator science and technology have evolved as accelerators became larger and important to a broad range of science. Physical Review Special Topics - Accelerators and Beams was established to serve the accelerator community as a timely, widely circulated, international journal covering the full breadth of accelerators and beams. The history of the journal and the innovations associated with it are reviewed.

  5. The Accelerated Kepler Problem

    CERN Document Server

    Namouni, Fathi

    2007-01-01

    The accelerated Kepler problem is obtained by adding a constant acceleration to the classical two-body Kepler problem. This setting models the dynamics of a jet-sustaining accretion disk and its content of forming planets as the disk loses linear momentum through the asymmetric jet-counterjet system it powers. The dynamics of the accelerated Kepler problem is analyzed using physical as well as parabolic coordinates. The latter naturally separate the problem's Hamiltonian into two unidimensional Hamiltonians. In particular, we identify the origin of the secular resonance in the accelerated Kepler problem and determine analytically the radius of stability boundary of initially circular orbits that are of particular interest to the problem of radial migration in binary systems as well as to the truncation of accretion disks through stellar jet acceleration.

  6. On Accelerated Black Holes

    CERN Document Server

    Letelier, P S; Letelier, Patricio S.; Oliveira, Samuel R.

    1998-01-01

    The C-metric is revisited and global interpretation of some associated spacetimes are studied in some detail. Specially those with two event horizons, one for the black hole and another for the acceleration. We found that the spacetime fo an accelerated Schwarzschild black hole is plagued by either conical singularities or lack of smoothness and compactness of the black hole horizon. By using standard black hole thermodynamics we show that accelerated black holes have higher Hawking temperature than Unruh temperature. We also show that the usual upper bound on the product of the mass and acceleration parameters (<1/sqrt(27)) is just a coordinate artifact. The main results are extended to accelerated Kerr black holes. We found that they are not changed by the black hole rotation.

  7. Induced activation in accelerator components

    Directory of Open Access Journals (Sweden)

    Cristian Bungau

    2014-08-01

    Full Text Available The residual activity induced in particle accelerators is a serious issue from the point of view of radiation safety as the long-lived radionuclides produced by fast or moderated neutrons and impact protons cause problems of radiation exposure for staff involved in the maintenance work and when decommissioning the facility. This paper presents activation studies of the magnets and collimators in the High Energy Beam Transport line of the European Spallation Source due to the backscattered neutrons from the target and also due to the direct proton interactions and their secondaries. An estimate of the radionuclide inventory and induced activation are predicted using the GEANT4 code.

  8. Insights on the post-seismic geomorphological response to the 2008 Wenchuan Earthquake from detrital cosmogenic nuclides data

    Science.gov (United States)

    Wang, Wei; Godard, Vincent; Liu-Zeng, Jing; Scherler, Dirk; Xu, Chong; Xu, Quiang; Xie, Kejia; Bellier, Olivier; Ansberque, Claire; de Sigoyer, Julia; Aster Team

    2016-04-01

    In high-relief mountain ranges bounded by reverse faults, large-magnitude earthquakes can contribute to topographic growth by co- and inter-seismic surface uplift of the hanging wall; meanwhile, earthquakes can also lower relief by causing erosion through extensive landslides. Quantifying evacuation process of co-seismic landslides material is central to our understanding of mass redistribution at the earth surface and the evolution of active mountain ranges. The 2008 Mw 7.9 Wenchuan earthquake in the Longmen Shan range of eastern Tibet provides a valuable opportunity to evaluate such direct impact. Cosmogenic nuclides concentrations in river sands are diluted by the input of low-concentration landslide debris materials after the earthquake (West et al., 2014), and we document the evolution 10Be concentrations in quartz for several years after the Wenchuan earthquake to trace the routing processes of co-seismic landslides. Over the 2008-2013 period we collected river sand samples at 19 locations annually along the rivers that flow through the rupture zone. When compared with published pre-earthquake data, our results show that the 10Be concentration in river sand declined dramatically after the earthquake at all sampling sites. Meanwhile, multi-year time series of 10Be concentration at single sites present roughly constant level of dilution with moderate fluctuations. Our analyses indicate that the 10Be dilution amplitude is closely controlled by local catchment slope and landslide density, rather than by the location of landslides with respect to sampling sites. The perturbation we observed for 10Be concentrations in the 0.25~1 mm size fraction appears to be sustained over the timescale of our survey with no clear relaxation, which is consistent with independent results from suspended sediment analysis (Wang et al., 2015).

  9. ANEMOS: A computer code to estimate air concentrations and ground deposition rates for atmospheric nuclides emitted from multiple operating sources

    Energy Technology Data Exchange (ETDEWEB)

    Miller, C.W.; Sjoreen, A.L.; Begovich, C.L.; Hermann, O.W.

    1986-11-01

    This code estimates concentrations in air and ground deposition rates for Atmospheric Nuclides Emitted from Multiple Operating Sources. ANEMOS is one component of an integrated Computerized Radiological Risk Investigation System (CRRIS) developed for the US Environmental Protection Agency (EPA) for use in performing radiological assessments and in developing radiation standards. The concentrations and deposition rates calculated by ANEMOS are used in subsequent portions of the CRRIS for estimating doses and risks to man. The calculations made in ANEMOS are based on the use of a straight-line Gaussian plume atmospheric dispersion model with both dry and wet deposition parameter options. The code will accommodate a ground-level or elevated point and area source or windblown source. Adjustments may be made during the calculations for surface roughness, building wake effects, terrain height, wind speed at the height of release, the variation in plume rise as a function of downwind distance, and the in-growth and decay of daughter products in the plume as it travels downwind. ANEMOS can also accommodate multiple particle sizes and clearance classes, and it may be used to calculate the dose from a finite plume of gamma-ray-emitting radionuclides passing overhead. The output of this code is presented for 16 sectors of a circular grid. ANEMOS can calculate both the sector-average concentrations and deposition rates at a given set of downwind distances in each sector and the average of these quantities over an area within each sector bounded by two successive downwind distances. ANEMOS is designed to be used primarily for continuous, long-term radionuclide releases. This report describes the models used in the code, their computer implementation, the uncertainty associated with their use, and the use of ANEMOS in conjunction with other codes in the CRRIS. A listing of the code is included in Appendix C.

  10. New Insights on Long Term Geomagnetic Moment Variation from Cosmogenic Nuclide and Paleointensity Signatures along Ocean Sediment Cores.

    Science.gov (United States)

    Thouveny, N.; Bourles, D. L.; Valet, J. P.; Bassinot, F. C.; Ménabréaz, L.; Simon, Q.; Demory, F.; Valery, G.; Vidal, L.; Beaufort, L.; de Garidel-Thoron, T.

    2015-12-01

    Some numerical and experimental simulations suggest that precession might supply enough power to influence planetary dynamos. The demonstration of a causal relationship between the Earth's orbital motion and variations of the geomagnetic field intensity, would open interesting perspective for modelling the past and future geomagnetic field behaviour and its eventual relationships to past and future orbitally constrained, climatic changes. Although pristine geomagnetic signals can be extracted by filtering and stacking multiple normalized intensity records, the reconstruction of high resolution geomagnetic field variations still raises questions. Namely, significant variance at orbital frequencies in relative paleointensity (RPI) records are generally considered as clues of residual contamination by paleoclimatically induced variations of magnetic carriers size ranges or mineralogy. Such questions can be adressed using other indicators of the geomagnetic dipole moment variation, such as the cosmogenic production modulated by the magnetospheric shielding. During the MAGORB project (ANR-09-BLAN-053-001) cosmogenic nuclide geochemistry, d18O, and paleomagnetic records were constructed along thick clayey-carbonate sequences deposited in the equatorial pacific and indian oceans over the last million of years. Authigenic 10Be/9Be ratio and RPI variations generally exhibit similar ranges of oscillations. However significant offsets appear between some RPI lows and their corresponding 10Be/9Be peaks, suggesting delayed lock-in of the remanent magnetization. After transfer on time scales the new geomagnetic moment series can be compared with the PISO-1500 and SINT-2000 stacks, and with the 10Be ice core record of EPICA Dome C. These new authigenic 10Be/9Be ratio records provide new opportunities to: 1) assess the validity of high resolution RPI records, 2) evaluate address the question of the presence of orbital periods in the paleo-field geomagnetic spectrum, and 3) to

  11. Extracting dynamic topography from river profiles and cosmogenic nuclide geochronology in the Middle Atlas and the High Plateaus of Morocco

    Science.gov (United States)

    Pastor, Alvar; Babault, Julien; Owen, Lewis A.; Teixell, Antonio; Arboleya, María-Luisa

    2015-11-01

    The Moulouya river system has intensely eroded the Arhbalou, Missour, and Guercif Neogene foreland basins in northeastern Morocco, having changed from net aggradation during the Miocene-early Pliocene to net incision punctuated by alluvial fan deposition at late Pliocene or early Quaternary time. This region as a whole has experienced mantle-driven, surface uplift (dynamic topography) since the late Cenozoic, being locally affected by uplift due to crustal shortening and thickening of the Middle Atlas too. Knickpoints located along the major streams of the Moulouya fluvial network, appear on both the undeformed margins of the Missour and Guercif foreland basins (High Plateaus), as well as along the thrust mountain front of the southern Middle Atlas, where they reach heights of 800-1000 m. 500-550 m of the knickpoint vertical incision might be explained by long-wavelength mantle-driven dynamic surface uplift, whereas the remaining 450-500 m in the southern Middle Atlas front and 200-300 m in the northeastern Middle Atlas front seem to be thrust-related uplift of the Jebel Bou Naceur. Be-10 terrestrial cosmogenic nuclides have been used to date two Quaternary river terraces in the Chegg Ard valley at 62 ± 14 ka and 411 ± 55 ka. The dated terraces allow the incision rates associated with the frontal structures of the Middle Atlas to be estimated at ~ 0.3 mm yr- 1. Furthermore, these ages have served to evaluate mantle-driven regional surface uplift since the middle Pleistocene in the central Missour basin, yielding values of ~ 0.1-0.2 mm yr- 1.

  12. A new awakening for accelerator cavities

    CERN Multimedia

    Katarina Anthony

    2013-01-01

    Imagine: an accelerator unbound by length; one that can bring a beam up to the TeV level in just a few hundred metres. Sounds like a dream? Perhaps not for long. At CERN’s Proton Driven Plasma Wakefield Acceleration Experiment (AWAKE), physicists may soon be working to bring this contemporary fairy-tale to life.   The AWAKE experiment in the CNGS facility. Wherever you find a modern linear particle accelerator, you’ll find with it a lengthy series of RF accelerating cavities. Although based on technology first developed over half a century ago, RF cavities have dominated the accelerating world since their inception. However, new developments in plasma accelerator systems may soon be bringing a new player into the game. By harnessing the power of wakefields generated by beams in plasma cells, physicists may be able to produce accelerator gradients of many GV/m –  hundreds of times higher than those achieved in current RF cavities. “Plasma wakef...

  13. Compensation Techniques in Accelerator Physics

    Energy Technology Data Exchange (ETDEWEB)

    Sayed, Hisham Kamal [Old Dominion Univ., Norfolk, VA (United States)

    2011-05-01

    Accelerator physics is one of the most diverse multidisciplinary fields of physics, wherein the dynamics of particle beams is studied. It takes more than the understanding of basic electromagnetic interactions to be able to predict the beam dynamics, and to be able to develop new techniques to produce, maintain, and deliver high quality beams for different applications. In this work, some basic theory regarding particle beam dynamics in accelerators will be presented. This basic theory, along with applying state of the art techniques in beam dynamics will be used in this dissertation to study and solve accelerator physics problems. Two problems involving compensation are studied in the context of the MEIC (Medium Energy Electron Ion Collider) project at Jefferson Laboratory. Several chromaticity (the energy dependence of the particle tune) compensation methods are evaluated numerically and deployed in a figure eight ring designed for the electrons in the collider. Furthermore, transverse coupling optics have been developed to compensate the coupling introduced by the spin rotators in the MEIC electron ring design.

  14. LEP superconducting accelerating cavity module

    CERN Multimedia

    With its 27-kilometre circumference, the Large Electron-Positron (LEP) collider was – and still is – the largest electron-positron accelerator ever built. The excavation of the LEP tunnel was Europe’s largest civil-engineering project prior to the Channel Tunnel. Three tunnel-boring machines started excavating the tunnel in February 1985 and the ring was completed three years later. In its first phase of operation, LEP consisted of 5176 magnets and 128 accelerating cavities. CERN’s accelerator complex provided the particles and four enormous detectors, ALEPH, DELPHI, L3 and OPAL, observed the collisions. LEP was commissioned in July 1989 and the first beam circulated in the collider on 14 July. The collider's initial energy was chosen to be around 91 GeV, so that Z bosons could be produced. The Z boson and its charged partner the W boson, both discovered at CERN in 1983, are responsible for the weak force, which drives the Sun, for example. Observing the creation and decay of the short-lived Z boson w...

  15. Diffusive Shock Acceleration the Fermi Mechanism

    CERN Document Server

    Baring, M G

    1997-01-01

    The mechanism of diffusive Fermi acceleration at collisionless plasma shock waves is widely invoked in astrophysics to explain the appearance of non-thermal particle populations in a variety of environments, including sites of cosmic ray production, and is observed to operate at several sites in the heliosphere. This review outlines the principal results from the theory of diffusive shock acceleration, focusing first on how it produces power-law distributions in test-particle regimes, where the shock dynamics are dominated by the thermal populations that provide the seed particles for the acceleration process. Then the importance of non-linear modifications to the shock hydrodynamics by the accelerated particles is addressed, emphasizing how these subsequently influence non-thermal spectral formation.

  16. Merging conventional and laser wakefield accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Zeitler, Benno; Schnepp, Matthias; Gehrke, Tim; Gruener, Florian [Hamburg Univ. (Germany); Center for Free-Electron Laser Science (Germany); Grebenyuk, Julia; Mehrling, Timon; Osterhoff, Jens [Hamburg Univ. (Germany); Floettmann, Klaus [Deutsches Elektronen-Synchrotron (DESY) (Germany)

    2013-07-01

    Laser wakefield accelerators deliver high quality electron beams in terms of emittance and bunch length. However there are also parameters which cannot compete with conventional machines, namely spectral width and shot to shot stability. One reason for that is that there is no direct access to the injection mechanism. Injecting a well-characterized electron beam produced by a conventional accelerator into a plasma wakefield could help to solve that problem, since such a pump-probe type experiment should allow for a direct reconstruction of the field distribution and a better understanding of the injection process. REGAE at DESY in Hamburg is a suited accelerator for such a type of experiment. We report on the status of the beamline extension at REGAE and the plans towards the external injection project with the goal to directly measure the wakefield and further improve the stability of laser wakefield accelerators.

  17. Laser acceleration... now with added fibre

    CERN Document Server

    Katarina Anthony

    2012-01-01

    Laser acceleration technology is plagued by two main issues: efficiency and repetition rates. In other words, lasers consume too much power and cannot sustain accelerating particles long enough to produce collisions. ICAN, a new EU-funded project, is examining how fibre lasers may help physicists tackle these issues.   A diode-pumped fibre laser. (Image courtesy of Laser Zentrum Hannover.) The International Coherent Amplification Network (ICAN) is studying the potential of lasers for collision physics. CERN is a beneficiary of the project and will collaborate with 15 other institutes from around the world, including KEK in Japan, Fermilab in the USA, and DESY in Germany. “The network is looking into existing fibre laser technology, which we believe has fantastic potential for accelerators,” says Gerard Mourou, ICAN co-ordinator at the École Polytechnique in France. “The hope is to make laser acceleration competitive with traditional radio-fre...

  18. Neutron Source from Laser Plasma Acceleration

    Science.gov (United States)

    Jiao, Xuejing; Shaw, Joseph; McCary, Eddie; Downer, Mike; Hegelich, Bjorn

    2016-10-01

    Laser driven electron beams and ion beams were utilized to produce neutron sources via different mechanism. On the Texas Petawatt laser, deuterized plastic, gold and DLC foil targets of varying thickness were shot with 150 J , 150 fs laser pulses at a peak intensity of 2 ×1021W /cm2 . Ions were accelerated by either target normal sheath acceleration or Breakout Afterburner acceleration. Neutrons were produced via the 9Be(d,n) and 9Be(p,n) reactions when accelerated ions impinged on a Beryllium converter as well as by deuteron breakup reactions. We observed 2 ×1010 neutron per shot in average, corresponding to 5 ×1018n /s . The efficiencies for different targets are comparable. In another experiment, 38fs , 0.3 J UT3 laser pulse interacted with mixed gas target. Electrons with energy 40MeV were produced via laser wakefield acceleration. Neutron flux of 2 ×106 per shot was generated through bremsstrahlung and subsequent photoneutron reactions on a Copper converter.

  19. Accelerating DSMC data extraction.

    Energy Technology Data Exchange (ETDEWEB)

    Gallis, Michail A.; Piekos, Edward Stanley

    2006-10-01

    In many direct simulation Monte Carlo (DSMC) simulations, the majority of computation time is consumed after the flowfield reaches a steady state. This situation occurs when the desired output quantities are small compared to the background fluctuations. For example, gas flows in many microelectromechanical systems (MEMS) have mean speeds more than two orders of magnitude smaller than the thermal speeds of the molecules themselves. The current solution to this problem is to collect sufficient samples to achieve the desired resolution. This can be an arduous process because the error is inversely proportional to the square root of the number of samples so we must, for example, quadruple the samples to cut the error in half. This work is intended to improve this situation by employing more advanced techniques, from fields other than solely statistics, for determining the output quantities. Our strategy centers on exploiting information neglected by current techniques, which collect moments in each cell without regard to one another, values in neighboring cells, nor their evolution in time. Unlike many previous acceleration techniques that modify the method itself, the techniques examined in this work strictly post-process so they may be applied to any DSMC code without affecting its fidelity or generality. Many potential methods are drawn from successful applications in a diverse range of areas, from ultrasound imaging to financial market analysis. The most promising methods exploit relationships between variables in space, which always exist in DSMC due to the absence of shocks. Disparate techniques were shown to produce similar error reductions, suggesting that the results shown in this report may be typical of what is possible using these methods. Sample count reduction factors of approximately three to five were found to be typical, although factors exceeding ten were shown on some variables under some techniques.

  20. Accelerated coffee pulp composting.

    Science.gov (United States)

    Sánchez, G; Olguín, E J; Mercado, G

    1999-02-01

    The effect of two abundant, easily available and very low-cost agro-industrial organic residues, i.e., filter cake from the sugar industry and poultry litter, on the composting stabilization time of coffee pulp and on the quality of the produced compost, was evaluated. Piles of one cubic meter were built and monitored within the facilities of a coffee processing plant in the Coatepec region of the State of Veracruz, Mexico. Manual aeration was carried out once a week. A longer thermophilic period (28 days) and a much lower C/N ratio (in the range of 6.9-9.1) were observed in the piles containing the amendments, as compared to the control pile containing only coffee pulp (14 days and a C/N ratio of 14.4, respectively). The maximum assimilation rate of the reducing sugars was 1.6 g kg-1 d-1 (from 7.5 to 5.3%) during the first two weeks when accelerators were present in the proportion of 20% filter cake plus 20% poultry litter, while they accumulated at a rate of 1.2 g kg-1 d-1 (from 7.4 to 9.13%) during the same period in the control pile. The best combination of amendments was 30% filter cake with 20% poultry litter, resulting in a final nitrogen content as high as 4.81%. The second best combination was 20% filter cake with 10% poultry litter, resulting in a compost which also contained a high level of total nitrogen (4.54%). It was concluded that the use of these two residues enhanced the composting process of coffee pulp, promoting a shorter stabilization period and yielding a higher quality of compost.

  1. Particle acceleration by plasma

    CERN Document Server

    Ogata, A

    2002-01-01

    Plasma acceleration is carried out by using potential of plasma wave. It is classified by generation method of plasma wave such as the laser wake-field acceleration and the beat wave acceleration. Other method using electron beam is named the plasma wake-field acceleration (or beam wake-field acceleration). In this paper, electron acceleration by laser wake-field in gas plasma, ion source by laser radiation of solid target and nanoion beam generation by one component of plasma in trap are explained. It is an applicable method that ions, which run out from the solid target irradiated by laser, are used as ion source of accelerator. The experimental system using 800 nm laser, 50 mJ pulse energy and 50 fs pulse width was studied. The laser intensity is 4x10 sup 1 sup 6 Wcm sup - sup 2 at the focus. The target film of metal and organic substance film was used. When laser irradiated Al target, two particles generated, in front and backward. It is new fact that the neutral particle was obtained in front, because it...

  2. Cosmic particle acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Zimbardo, Gaetano; Perri, Silvia [Universita della Calabria, Dipartimento di Fisica, 87036 Rende (Italy)

    2014-07-01

    The most popular mechanism for the acceleration of cosmic rays, which is thought to operate in supernova remnant shocks as well as at heliospheric shocks, is the diffusive shock acceleration, which is a Fermi mechanism based on normal diffusion. On the other hand, in the last few years it has been shown that the transport of plasma particles in the presence of electric and magnetic turbulence can be superdiffusive rather than normal diffusive. The term 'superdiffusive' refers to the mean square displacement of particle positions growing superlinearly with time, as compared to the normal linear growth. In particular, superdiffusion is characterized by a non Gaussian statistical process called Levy random walk. We show how diffusive shock acceleration is modified by superdiffusion, and how this yields new predictions for the cosmic ray spectral index, for the acceleration time, and for the spatial profile of energetic particles. A comparison with observations of particle acceleration at heliospheric shocks and at supernova remnant shocks is done. We discuss how superdiffusive shock acceleration allows to explain the observations of hard ion spectra at the solar wind termination shock detected by Voyager 2, of hard radio spectra due to synchrotron emission of electrons accelerated at supernova remnant shocks, and how it can help to explain the observations of 'thin rims' in the X-ray synchrotron emission.

  3. Multicavity proton cyclotron accelerator

    Directory of Open Access Journals (Sweden)

    J. L. Hirshfield

    2002-08-01

    Full Text Available A mechanism for acceleration of protons is described, in which energy gain occurs near cyclotron resonance as protons drift through a sequence of rotating-mode TE_{111} cylindrical cavities in a strong nearly uniform axial magnetic field. Cavity resonance frequencies decrease in sequence from one another with a fixed frequency interval Δf between cavities, so that synchronism can be maintained between the rf fields and proton bunches injected at intervals of 1/Δf. An example is presented in which a 122 mA, 1 MeV proton beam is accelerated to 961 MeV using a cascade of eight cavities in an 8.1 T magnetic field, with the first cavity resonant at 120 MHz and with Δf=8 MHz. Average acceleration gradient exceeds 40 MV/m, average effective shunt impedance is 223 MΩ/m, but maximum surface field in the cavities does not exceed 7.2 MV/m. These features occur because protons make many orbital turns in each cavity and thus experience acceleration from each cavity field many times. Longitudinal and transverse stability appear to be intrinsic properties of the acceleration mechanism, and an example to illustrate this is presented. This acceleration concept could be developed into a proton accelerator for a high-power neutron spallation source, such as that required for transmutation of nuclear waste or driving a subcritical fission burner, provided a number of significant practical issues can be addressed.

  4. Diffusive shock acceleration at laser driven shocks: studying cosmic-ray accelerators in the laboratory

    CERN Document Server

    Reville, B; Gregori, G

    2012-01-01

    The non-thermal particle spectra responsible for the emission from many astrophysical systems are thought to originate from shocks via a first order Fermi process otherwise known as diffusive shock acceleration. The same mechanism is also widely believed to be responsible for the production of high energy cosmic rays. With the growing interest in collisionless shock physics in laser produced plasmas, the possibility of reproducing and detecting shock acceleration in controlled laboratory experiments should be considered. The various experimental constraints that must be satisfied are reviewed. It is demonstrated that several currently operating laser facilities may fulfil the necessary criteria to confirm the occurrence of diffusive shock acceleration of electrons at laser produced shocks. Successful reproduction of Fermi acceleration in the laboratory could open a range of possibilities, providing insight into the complex plasma processes that occur near astrophysical sources of cosmic rays.

  5. Application of Accelerators and Storage Rings: Accelerators in Medicine

    CERN Document Server

    Amaldi, U

    2013-01-01

    This document is part of Subvolume C 'Accelerators and Colliders' of Volume 21 'Elementary Particles' of Landolt-Börnstein - Group I 'Elementary Particles, Nuclei and Atoms'. It contains the the Section '11.3 Accelerators in Medicine' of the Chapter '11 Application of Accelerators and Storage Rings' with the content: 11.3 Accelerators in Medicine 11.3.1 Accelerators and Radiopharmaceuticals 11.3.2 Accelerators and Cancer Therapy

  6. Confronting Twin Paradox Acceleration

    Science.gov (United States)

    Murphy, Thomas W.

    2016-05-01

    The resolution to the classic twin paradox in special relativity rests on the asymmetry of acceleration. Yet most students are not exposed to a satisfactory analysis of what exactly happens during the acceleration phase that results in the nonaccelerated observer's more rapid aging. The simple treatment presented here offers both graphical and quantitative solutions to the problem, leading to the correct result that the acceleration-induced age gap is 2Lβ years when the one-way distance L is expressed in light-years and velocity β ≡v/c .

  7. Reducing the overheads of hardware acceleration through datapath integration

    Science.gov (United States)

    Jääskeläinen, Pekka; Kultala, Heikki; Pitkänen, Teemu; Takala, Jarmo

    2008-02-01

    Hardware accelerators are used to speed up execution of specific tasks such as video coding. Often the purpose of hardware acceleration is to be able to use a cheaper or, for example, more energy economical processor for executing the majority of the application in software. However, when using hardware acceleration, new overheads are produced mainly due to the need to transfer data to and from the accelerator and signaling the readiness of the accelerator computation to the processor. We find the traditional mechanisms suboptimal for fine-grain hardware acceleration, especially when energy efficiency is important. This paper explores a technique unique to Transport Triggered Architectures to interface with hardware accelerators. The proposed technique places hardware accelerators to the processor data path, making them visible as regular function units to the programmer. This way communication costs are reduced as data can be transferred directly to the accelerator from other processor data path components and synchronization can be done by polling a simple ready flag in the accelerator function unit. Additionally, this setup enables the instruction scheduler of the compiler to schedule the hardware accelerator like any other operation, thus partially hide its latency with other program operations. The paper presents a case study with an audio decoder application in which fine-grain and coarse-grain hardware accelerators are integrated to the processor data path as function units. The case is used to study several different synchronization, communication, and latency-hiding techniques enabled by this kind of setup.

  8. Accelerating electromagnetic magic field from the C-metric

    CERN Document Server

    Bicak, Jiri; 10.1007/s10714-009-0816-8

    2009-01-01

    Various aspects of the C-metric representing two rotating charged black holes accelerated in opposite directions are summarized and its limits are considered. A particular attention is paid to the special-relativistic limit in which the electromagnetic field becomes the "magic field" of two oppositely accelerated rotating charged relativistic discs. When the acceleration vanishes the usual electromagnetic magic field of the Kerr-Newman black hole with gravitational constant set to zero arises. Properties of the accelerated discs and the fields produced are studied and illustrated graphically. The charges at the rim of the accelerated discs move along spiral trajectories with the speed of light. If the magic field has some deeper connection with the field of the Dirac electron, as is sometimes conjectured because of the same gyromagnetic ratio, the "accelerating magic field" represents the electromagnetic field of a uniformly accelerated spinning electron. It generalizes the classical Born's solution for two u...

  9. Vibration control in accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Montag, C.

    2011-01-01

    In the vast majority of accelerator applications, ground vibration amplitudes are well below tolerable magnet jitter amplitudes. In these cases, it is necessary and sufficient to design a rigid magnet support structure that does not amplify ground vibration. Since accelerator beam lines are typically installed at an elevation of 1-2m above ground level, special care has to be taken in order to avoid designing a support structure that acts like an inverted pendulum with a low resonance frequency, resulting in untolerable lateral vibration amplitudes of the accelerator components when excited by either ambient ground motion or vibration sources within the accelerator itself, such as cooling water pumps or helium flow in superconducting magnets. In cases where ground motion amplitudes already exceed the required jiter tolerances, for instance in future linear colliders, passive vibration damping or active stabilization may be considered.

  10. Rejuvenating CERN's Accelerators

    CERN Multimedia

    2004-01-01

    In the coming years and especially in 2005, CERN's accelerators are going to receive an extensive renovation programme to ensure they will perform reliably and effectively when the LHC comes into service.

  11. Joint International Accelerator School

    CERN Multimedia

    CERN Accelerator School

    2014-01-01

    The CERN and US Particle Accelerator Schools recently organised a Joint International Accelerator School on Beam Loss and Accelerator Protection, held at the Hyatt Regency Hotel, Newport Beach, California, USA from 5-14 November 2014. This Joint School was the 13th in a series of such schools, which started in 1985 and also involves the accelerator communities in Japan and Russia.   Photo courtesy of Alfonse Pham, Michigan State University.   The school attracted 58 participants representing 22 different nationalities, with around half from Europe and the other half from Asia and the Americas. The programme comprised 26 lectures, each of 90 minutes, and 13 hours of case study. The students were given homework each day and had an opportunity to sit a final exam, which counted towards university credit. Feedback from the participants was extremely positive, praising the expertise and enthusiasm of the lecturers, as well as the high standard and quality of their lectures. Initial dis...

  12. Dielectric assist accelerating structure

    Science.gov (United States)

    Satoh, D.; Yoshida, M.; Hayashizaki, N.

    2016-01-01

    A higher-order TM02 n mode accelerating structure is proposed based on a novel concept of dielectric loaded rf cavities. This accelerating structure consists of ultralow-loss dielectric cylinders and disks with irises which are periodically arranged in a metallic enclosure. Unlike conventional dielectric loaded accelerating structures, most of the rf power is stored in the vacuum space near the beam axis, leading to a significant reduction of the wall loss, much lower than that of conventional normal-conducting linac structures. This allows us to realize an extremely high quality factor and a very high shunt impedance at room temperature. A simulation of a 5 cell prototype design with an existing alumina ceramic indicates an unloaded quality factor of the accelerating mode over 120 000 and a shunt impedance exceeding 650 M Ω /m at room temperature.

  13. A New Accelerator-Based Mass Spectrometry.

    Science.gov (United States)

    Gove, H. E.

    1983-01-01

    Tandem electrostatic accelerators produce beams of positive ions which are used to penetrate atomic nuclei in a target, inducing nuclear reactions whose study elucidates varied properties of the nucleus. Uses of the system, which acts like a mass spectrometer, are discussed. These include radiocarbon dating measurements. (JN)

  14. Production of S-band Accelerating Structures

    CERN Document Server

    Piel, C; Vogel, H; Vom Stein, P

    2004-01-01

    ACCEL currently produces accelerating structures for several scientific laboratories. Multi-cell cavities at S-band frequencies are required for the projects CLIC-driver-linac, DLS and ASP pre-injector linac and the MAMI-C microtron. Based on those projects differences and similarities in design, production technologies and requirements will be addressed.

  15. Sinopec Accelerates Its Strategy for Internationalization

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ China Petrochemical Corporation(Sinopec)is obviously accelerating its strategy for acquisition of overseas oil and gas assets in 2010.The second largest oil and gas producer in China aims to take advantage of the worldwide resources to meet the country's oil demand that is rising at a double-digit growth rate.

  16. LHCb GPU Acceleration Project

    CERN Document Server

    AUTHOR|(SzGeCERN)744808; Campora Perez, Daniel Hugo; Neufeld, Niko; Vilasis Cardona, Xavier

    2016-01-01

    The LHCb detector is due to be upgraded for processing high-luminosity collisions, which will increase the load on its computation infrastructure from 100 GB/s to 4 TB/s, encouraging us to look for new ways of accelerating the Online reconstruction. The Coprocessor Manager is our new framework for integrating LHCb’s existing computation pipelines with massively parallel algorithms running on GPUs and other accelerators. This paper describes the system and analyzes its performance.

  17. Accelerating News Issue 2

    CERN Document Server

    Kahle, K; Wildner, E

    2012-01-01

    In this summer issue we look at how developments in collimator materials could have applications in aerospace and beyond, and how Polish researchers are harnessing accelerators for medical and industrial uses. We see how the LHC luminosity upgrade is linking with European industry and US researchers, and how the neutrino oscillation community is progressing. We find out the mid-term status of TIARA-PP and how it is mapping European accelerator education resources.

  18. Accelerating Cosmologies from Compactification

    CERN Document Server

    Townsend, P K; Townsend, Paul K.; Wohlfarth, Mattias N.R.

    2003-01-01

    A solution of the (4+n)-dimensional vacuum Einstein equations is found for which spacetime is compactified on a compact hyperbolic manifold of time-varying volume to a flat four-dimensional FLRW cosmology undergoing accelerated expansion in Einstein conformal frame. This shows that the `no-go' theorem forbidding acceleration in `standard' (time-independent) compactifications of string/M-theory does not apply to `cosmological' (time-dependent) hyperbolic compactifications.

  19. Dense plasma focus (DPF) accelerated non radio isotopic radiological source

    Energy Technology Data Exchange (ETDEWEB)

    Rusnak, Brian; Tang, Vincent

    2017-01-31

    A non-radio-isotopic radiological source using a dense plasma focus (DPF) to produce an intense z-pinch plasma from a gas, such as helium, and which accelerates charged particles, such as generated from the gas or injected from an external source, into a target positioned along an acceleration axis and of a type known to emit ionizing radiation when impinged by the type of accelerated charged particles. In a preferred embodiment, helium gas is used to produce a DPF-accelerated He2+ ion beam to a beryllium target, to produce neutron emission having a similar energy spectrum as a radio-isotopic AmBe neutron source. Furthermore, multiple DPFs may be stacked to provide staged acceleration of charged particles for enhancing energy, tunability, and control of the source.

  20. Biomedical accelerator mass spectrometry

    Science.gov (United States)

    Freeman, Stewart P. H. T.; Vogel, John S.

    1995-05-01

    Ultrasensitive SIMS with accelerator based spectrometers has recently begun to be applied to biomedical problems. Certain very long-lived radioisotopes of very low natural abundances can be used to trace metabolism at environmental dose levels ( [greater-or-equal, slanted] z mol in mg samples). 14C in particular can be employed to label a myriad of compounds. Competing technologies typically require super environmental doses that can perturb the system under investigation, followed by uncertain extrapolation to the low dose regime. 41Ca and 26Al are also used as elemental tracers. Given the sensitivity of the accelerator method, care must be taken to avoid contamination of the mass spectrometer and the apparatus employed in prior sample handling including chemical separation. This infant field comprises the efforts of a dozen accelerator laboratories. The Center for Accelerator Mass Spectrometry has been particularly active. In addition to collaborating with groups further afield, we are researching the kinematics and binding of genotoxins in-house, and we support innovative uses of our capability in the disciplines of chemistry, pharmacology, nutrition and physiology within the University of California. The field can be expected to grow further given the numerous potential applications and the efforts of several groups and companies to integrate more the accelerator technology into biomedical research programs; the development of miniaturized accelerator systems and ion sources capable of interfacing to conventional HPLC and GMC, etc. apparatus for complementary chemical analysis is anticipated for biomedical laboratories.

  1. Accelerators for America's Future

    Science.gov (United States)

    Bai, Mei

    2016-03-01

    Particle accelerator, a powerful tool to energize beams of charged particles to a desired speed and energy, has been the working horse for investigating the fundamental structure of matter and fundermental laws of nature. Most known examples are the 2-mile long Stanford Linear Accelerator at SLAC, the high energy proton and anti-proton collider Tevatron at FermiLab, and Large Hadron Collider that is currently under operation at CERN. During the less than a century development of accelerator science and technology that led to a dazzling list of discoveries, particle accelerators have also found various applications beyond particle and nuclear physics research, and become an indispensible part of the economy. Today, one can find a particle accelerator at almost every corner of our lives, ranging from the x-ray machine at the airport security to radiation diagnostic and therapy in hospitals. This presentation will give a brief introduction of the applications of this powerful tool in fundermental research as well as in industry. Challenges in accelerator science and technology will also be briefly presented

  2. Method Development for Rapid Analysis of Natural Radioactive Nuclides Using Sector Field Inductively Coupled Plasma Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Lim, J.M.; Ji, Y.Y.; Lee, H.; Park, J.H.; Jang, M.; Chung, K.H.; Kang, M.J.; Choi, G.S. [Korea Atomic Energy Research Institute (Korea, Republic of)

    2014-07-01

    As an attempt to reduce the social costs and apprehension arising from radioactivity in the environment, an accurate and rapid assessment of radioactivity is highly desirable. Naturally occurring radioactive materials (NORM) are widely spread throughout the environment. The concern with radioactivity from these materials has therefore been growing for the last decade. In particular, radiation exposure in the industry when handling raw materials (e.g., coal mining and combustion, oil and gas production, metal mining and smelting, mineral sands (REE, Ti, Zr), fertilizer (phosphate), and building materials) has been brought to the public's attention. To decide the proper handling options, a rapid and accurate analytical method that can be used to evaluate the radioactivity of radionuclides (e.g., {sup 238}U, {sup 235}U, {sup 232}Th, {sup 226}Ra, and {sup 40}K) should be developed and validated. Direct measuring methods such as alpha spectrometry, a liquid scintillation counter (LSC), and mass-spectrometry are usually used for the measurement of radioactivity in NORM samples, and they encounter the most significant difficulties during pretreatment (e.g., purification, speciation, and dilution/enrichment). Since the pretreatment process consequently plays an important role in the measurement uncertainty, method development and validation should be performed. Furthermore, a-spectrometry has a major disadvantage of a long counting time, while it has a prominent measurement capability at a very low activity level of {sup 238}U, {sup 235}U, {sup 232}Th, and {sup 226}Ra. Contrary to the α-spectrometry method, a measurement technique using ICP-MS allow radioactivity in many samples to be measured in a short time period with a high degree of accuracy and precision. In this study, a method was developed for a rapid analysis of natural radioactive nuclides using ICP-MS. A sample digestion process was established using LiBO{sub 2} fusion and Fe co-precipitation. A magnetic

  3. Simulation of radio nuclide migration in crystalline rock under influence of matrix diffusion and sorption kinetics: Code development and pre-assessment of migration experiment

    Energy Technology Data Exchange (ETDEWEB)

    Woerman, A.; Xu Shulan [Uppsala Univ. (Sweden). Inst. of Earth Sciences

    1996-04-01

    The overall objective of the present study is to illuminate how spatial variability in rock chemistry in combination with spatial variability in matrix diffusion affects the radio nuclide migration along single fractures in crystalline rock. Models for ground water flow and transport of radio nuclides in a single fracture with micro-fissures have been formulated on the basis of generally accepted physical and chemical principles. Limits for the validity of the models are stated. The model equations are solved by combining finite differences and finite element methods in a computer code package. The computational package consists of three parts, namely, a stochastic field generator, a sub-program that solves the flow problem and a sub-program that solves the transport problem in a single fracture with connecting micro-fissures. Migration experiments have been pre-assessed by simulations of breakthrough curves for a constant concentration change at the upstream boundary. Breakthrough curves are sensitive to variations of parameters, such as, fracture aperture, porosity, distribution coefficient and advection velocity. The impact of matrix diffusion and sorption is manifested in terms of a retention of radionuclides causing a prolonged breakthrough. Heterogeneous sorption was characterized with a variable distribution coefficient for which the coefficient of variation CV(K{sub d})=1 and the integral scale of an exponential covariance function is one tenth of the drill core`s length. Simulated breakthrough curves for the heterogeneous sorption case have a relative variance of 3% in comparison to that of homogeneous case. An appropriate experimental set up for investigation of the effect of matrix diffusion and sorption on radio nuclide migration experiments would be an aperture less than 1 mm and porosity larger than 0.5%. 36 refs, 19 figs.

  4. The protection of radioactive nuclide and nursing management in DSA room%DSA室应用放射性核素的防护与护理管理

    Institute of Scientific and Technical Information of China (English)

    张桂敏

    2009-01-01

    探讨DSA室核素的防护与护理管理.方法 回顾应用放射性核素~(125)I粒子防护上作及护理管理情况.结果 建立核素防护DSA室规范性管理,主要管理模式有人员管理、业务技能专业化管理、放射性药品及废弃物的管理、做好术前健康宣教等.结论 使患者在DSA室接受良好的核素治疗,在得到良好治疗的同时,也保护了工作环境,培养了一批专业护理人员.%Objective To discuss the protection of radioactive nuclide and nursing management in DSA room. Methods The clinical state of the protection of radioactive ~(131)I 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.

  5. 基于支持向量机的快速核素识别方法研究%The Study of Fast Nuclide Identification Method with SVM

    Institute of Scientific and Technical Information of China (English)

    谢先博; 张晖

    2014-01-01

    针对传统γ能谱核素识别算法在较低放射性水平下的情况下存在核素识别慢,对相干核素识别效果差的问题,基于统计学习理论提出了基于支持向量机的快速核素识别方法。本方法一方面通过对峰位确定方法改进来提高特征量提取的精确度,去除γ能谱中重叠峰对相干核素识别中的影响,另一方面使用支持向量机方法实现核素的快速分类。通过与传统方法的比对,新方法在识别相干核素方面达到了很好的识别效果。%Nuclide identification algorithm for energy spectrum at low level radioactive nuclide identification exits slow, poor re-sults on coherent radionuclide identification problem.based on statistical learning theory proposed based on support vector ma-chine quick radionuclide identification method. By this method one hand, spectrum data smoothing, peak position to determine ways to improve to improve the accuracy of feature extraction, removal of overlapping peaks in spectra for radionuclide identifica-tion of coherent effects, on the other hand using the support vector machine approach to nuclear prime fast classification. By com-parison with the traditional methods, the new method in identifying coherent nuclide has reached a good recognition results.

  6. Diffusive Shock Acceleration and Reconnection Acceleration Processes

    Science.gov (United States)

    Zank, G. P.; Hunana, P.; Mostafavi, P.; Le Roux, J. A.; Li, Gang; Webb, G. M.; Khabarova, O.; Cummings, A.; Stone, E.; Decker, R.

    2015-12-01

    Shock waves, as shown by simulations and observations, can generate high levels of downstream vortical turbulence, including magnetic islands. We consider a combination of diffusive shock acceleration (DSA) and downstream magnetic-island-reconnection-related processes as an energization mechanism for charged particles. Observations of electron and ion distributions downstream of interplanetary shocks and the heliospheric termination shock (HTS) are frequently inconsistent with the predictions of classical DSA. We utilize a recently developed transport theory for charged particles propagating diffusively in a turbulent region filled with contracting and reconnecting plasmoids and small-scale current sheets. Particle energization associated with the anti-reconnection electric field, a consequence of magnetic island merging, and magnetic island contraction, are considered. For the former only, we find that (i) the spectrum is a hard power law in particle speed, and (ii) the downstream solution is constant. For downstream plasmoid contraction only, (i) the accelerated spectrum is a hard power law in particle speed; (ii) the particle intensity for a given energy peaks downstream of the shock, and the distance to the peak location increases with increasing particle energy, and (iii) the particle intensity amplification for a particular particle energy, f(x,c/{c}0)/f(0,c/{c}0), is not 1, as predicted by DSA, but increases with increasing particle energy. The general solution combines both the reconnection-induced electric field and plasmoid contraction. The observed energetic particle intensity profile observed by Voyager 2 downstream of the HTS appears to support a particle acceleration mechanism that combines both DSA and magnetic-island-reconnection-related processes.

  7. Probabilities and energies to obtain the counting efficiency of electron-capture nuclides. KLMN model; Probabilidades y energias de reestructuracion atomica subsiguientes a la captura electronica. Modelo KLMN

    Energy Technology Data Exchange (ETDEWEB)

    Galiano, G.; Grau, A.

    1994-07-01

    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)

  8. Production, Characterization, and Acceleration of Optical Microbunches

    Energy Technology Data Exchange (ETDEWEB)

    Sears, Christopher M.S. [Stanford Univ., CA (United States)

    2008-06-20

    Optical microbunches with a spacing of 800 nm have been produced for laser acceleration research. The microbunches are produced using a inverse Free-Electron-Laser (IFEL) followed by a dispersive chicane. The microbunched electron beam is characterized by coherent optical transition radiation (COTR) with good agreement to the analytic theory for bunch formation. In a second experiment the bunches are accelerated in a second stage to achieve for the first time direct net acceleration of electrons traveling in a vacuum with visible light. This dissertation presents the theory of microbunch formation and characterization of the microbunches. It also presents the design of the experimental hardware from magnetostatic and particle tracking simulations, to fabrication and measurement of the undulator and chicane magnets. Finally, the dissertation discusses three experiments aimed at demonstrating the IFEL interaction, microbunch production, and the net acceleration of the microbunched beam. At the close of the dissertation, a separate but related research effort on the tight focusing of electrons for coupling into optical scale, Photonic Bandgap, structures is presented. This includes the design and fabrication of a strong focusing permanent magnet quadrupole triplet and an outline of an initial experiment using the triplet to observe wakefields generated by an electron beam passing through an optical scale accelerator.

  9. Comparison of Multi-field Coupling Analysis of Accelerator Cavity

    Institute of Scientific and Technical Information of China (English)

    LI; Chun-guang; LI; Jin-hai

    2013-01-01

    In the high power accelerator cavity,the joule heat produced by the electromagnetic fields causes the temperature of the cavity rising which leads to frequency changed,called frequency shift.The analysis of the effect of power to the frequency shift is an important task of accelerator cavity design.It involves heat,structure and high frequency analysis.

  10. Symmetry breaking and cosmic acceleration in scalar field models

    CERN Document Server

    Sadjadi, M Mohseni; Sepangi, H R

    2015-01-01

    We study the possible role of symmetry breaking in the onset of the acceleration of the Universe in a scalar field dark energy model. We propose a new scenario in which acceleration of the Universe is driven by a positive potential produced by means of symmetry breaking.

  11. Diagnostics for advanced laser acceleration experiments

    Energy Technology Data Exchange (ETDEWEB)

    Misuri, Alessio [Univ. of Pisa (Italy)

    2002-01-01

    The first proposal for plasma based accelerators was suggested by 1979 by Tajima and Dawson. Since then there has been a tremendous progress both theoretically and experimentally. The theoretical progress is particularly due to the growing interest in the subject and to the development of more accurate numerical codes for the plasma simulations (especially particle-in-cell codes). The experimental progress follows from the development of multi-terawatt laser systems based on the chirped-pulse amplification technique. These efforts have produced results in several experiments world-wide, with the detection of accelerated electrons of tens of MeV. The peculiarity of these advanced accelerators is their ability to sustain extremely large acceleration gradients. In the conventional radio frequency linear accelerators (RF linacs) the acceleration gradients are limited roughly to 100 MV/m; this is partially due to breakdown which occurs on the walls of the structure. The electrical breakdown is originated by the emission of the electrons from the walls of the cavity. The electrons cause an avalanche breakdown when they reach other metal parts of the RF linacs structure.

  12. Diagnostics for advanced laser acceleration experiments

    Energy Technology Data Exchange (ETDEWEB)

    Misuri, Alessio

    2002-06-01

    The first proposal for plasma based accelerators was suggested by 1979 by Tajima and Dawson. Since then there has been a tremendous progress both theoretically and experimentally. The theoretical progress is particularly due to the growing interest in the subject and to the development of more accurate numerical codes for the plasma simulations (especially particle-in-cell codes). The experimental progress follows from the development of multi-terawatt laser systems based on the chirped-pulse amplification technique. These efforts have produced results in several experiments world-wide, with the detection of accelerated electrons of tens of MeV. The peculiarity of these advanced accelerators is their ability to sustain extremely large acceleration gradients. In the conventional radio frequency linear accelerators (RF linacs) the acceleration gradients are limited roughly to 100 MV/m; this is partially due to breakdown which occurs on the walls of the structure. The electrical breakdown is originated by the emission of the electrons from the walls of the cavity. The electrons cause an avalanche breakdown when they reach other metal parts of the RF linacs structure.

  13. Addressing solar modulation and long-term uncertainties in scaling secondary cosmic rays for in situ cosmogenic nuclide applications [rapid communication

    Science.gov (United States)

    Lifton, Nathaniel A.; Bieber, John W.; Clem, John M.; Duldig, Marc L.; Evenson, Paul; Humble, John E.; Pyle, Roger

    2005-10-01

    Solar modulation affects the secondary cosmic rays responsible for in situ cosmogenic nuclide (CN) production the most at the high geomagnetic latitudes to which CN production rates are traditionally referenced. While this has long been recognized (e.g., D. Lal, B. Peters, Cosmic ray produced radioactivity on the Earth, in: K. Sitte (Ed.), Handbuch Der Physik XLVI/2, Springer-Verlag, Berlin, 1967, pp. 551-612 and D. Lal, Theoretically expected variations in the terrestrial cosmic ray production rates of isotopes, in: G.C. Castagnoli (Ed.), Proceedings of the Enrico Fermi International School of Physics 95, Italian Physical Society, Varenna 1988, pp. 216-233), these variations can lead to potentially significant scaling model uncertainties that have not been addressed in detail. These uncertainties include the long-term (millennial-scale) average solar modulation level to which secondary cosmic rays should be referenced, and short-term fluctuations in cosmic ray intensity measurements used to derive published secondary cosmic ray scaling models. We have developed new scaling models for spallogenic nucleons, slow-muon capture and fast-muon interactions that specifically address these uncertainties. Our spallogenic nucleon scaling model, which includes data from portions of 5 solar cycles, explicitly incorporates a measure of solar modulation ( S), and our fast- and slow-muon scaling models (based on more limited data) account for solar modulation effects through increased uncertainties. These models improve on previously published models by better sampling the observed variability in measured cosmic ray intensities as a function of geomagnetic latitude, altitude, and solar activity. Furthermore, placing the spallogenic nucleon data in a consistent time-space framework allows for a more realistic assessment of uncertainties in our model than in earlier ones. We demonstrate here that our models reasonably account for the effects of solar modulation on measured

  14. Small type accelerator. Try for accelerator driven system

    CERN Document Server

    Mori, Y

    2003-01-01

    FFAG (Fixed-field alternating gradient) accelerator for accelerator driven subcritical reactor, which aims to change from long-lived radioactive waste to short-lived radioactivity, is introduced. It is ring accelerator. The performance needed is proton as accelerator particle, 10MW (total) beam power, about 1GeV beam energy, >30% power efficiency and continuous beam. The feature of FFAG accelerator is constant magnetic field. PoP (Proof-of-principle)-FFAG accelerator, radial type, was run at first in Japan in 2000. The excursion is about some ten cm. In principle, beam can be injected and extracted at any place of ring. The 'multi-fish' acceleration can accelerate beams to 100% duty by repeating acceleration. 150MeV-FFAG accelerator has been started since 2001. It tried to practical use, for example, treatment of cancer. (S.Y.)

  15. Materials considerations in accelerator targets

    Science.gov (United States)

    Peacock, H. B.; Iyer, N. C.; Louthan, M. R.

    1995-09-01

    Future nuclear materials production and/or the burn-up of long lived radioisotopes may be accomplished through the capture of spallation produced neutrons in accelerators. Aluminum clad-lead and/or lead alloys has been proposed as a spallation target. Aluminum was the cladding choice because of the low neutron absorption cross section, fast radioactivity decay, high thermal conductivity, and excellent fabricability. Metallic lead and lead oxide powders were considered for the target core with the fabrication options being casting or powder metallurgy (PM). Scoping tests to evaluate gravity casting, squeeze casting, and casting and swaging processes showed that, based on fabricability and heat transfer considerations, squeeze casting was the preferred option for manufacture of targets with initial core cladding contact. Thousands of aluminum clad aluminum-lithium alloy core targets and control rods for tritium production have been fabricated by coextrusion processes and successfully irradiated in the SRS reactors. Tritium retention in, and release from, the coextruded product was modeled from experimental and operational data. The model assumed that tritium atoms, formed by the 6Li(n,a)3He reaction, were produced in solid solution in the Al-Li alloy. Because of the low solubility of hydrogen isotopes in aluminum alloys, the irradiated Al-Li rapidly became supersaturated in tritium. Newly produced tritium atoms were trapped by lithium atoms to form a lithium tritide. The effective tritium pressure required for trap or tritide stability was the equilibrium decomposition pressure of tritium over a lithium tritide-aluminum mixture. The temperature dependence of tritium release was determined by the permeability of the cladding to tritium and the local equilibrium at the trap sites. The model can be used to calculate tritium release from aluminum clad, aluminum-lithium alloy targets during postulated accelerator operational and accident conditions. This paper describes

  16. 原地生成宇宙成因核素在地学研究中的应用%Applications of in-situ Cosmogenic Nuclides in Earth Sciences

    Institute of Scientific and Technical Information of China (English)

    任静; 刘宇平; 杜谷; 李建忠; 高永娟

    2012-01-01

    传统测年方法(14C、热释光、光释光等)无法直接测量地貌面或基岩面的形成年代,利用宇宙生成核素定出的年代可以直接计算地质、地貌体的暴露年代和埋藏时代.随着测量仪器的长足进步,特别是加速器质谱(AMS)检出限(可测至106原子)的大幅度提高,原地生成宇宙成因核素定年技术给地貌学带来了革命性的变化,因此宇宙生成核素被广泛应用于古气候学、构造地质学、火山年代学及古地磁学等.本文阐释了原地生成宇宙核素定年方法的基本原理,并在地学领域应用的现有基础上,从冰川、断层、阶地等研究对象出发,以沉积物埋藏年龄、地表侵蚀速率、断层滑动速率等为研究内容,具体描述该定年技术在冰川地貌、构造地貌、地貌过程及地貌演化研究中的国内外研究现状,以及应用中尚待解决的诸如核素产生速率与空间、时间关系;样品地质、地貌条件对结果造成的不确定性等问题.%Terrestrial in situ cosmogenic nuclide (TCN) techniques can directly measure surface exposure ages and burial events but traditional 14C dating, thermoluminescence dating, luminescence dating, etc cannot. In addition, the rapid progress of measuring instrumentation accuracy and precision, especially the detection limit of Accelerated Mass Spectrometry (AMS) has greatly improved to 106 atoms. Therefore, TCN dating techniques have led to a revolutionary change, prompting increasing use in the nuclide earth sciences of paleoclimatology, structural geology, tephrochronology and paleomagnetism, for example. In this paper, the principles of TCN are briefly introduced. Based on existing applications, it describes the present field of burial age, erosion rate and faultslip rate for the glacier, fault slip and terrace, etc.. Current research work and problems in several specific earth science areas including glacial geomorphology, tectonic geomorphology

  17. Dielectric laser accelerators

    Science.gov (United States)

    England, R. Joel; Noble, Robert J.; Bane, Karl; Dowell, David H.; Ng, Cho-Kuen; Spencer, James E.; Tantawi, Sami; Wu, Ziran; Byer, Robert L.; Peralta, Edgar; Soong, Ken; Chang, Chia-Ming; Montazeri, Behnam; Wolf, Stephen J.; Cowan, Benjamin; Dawson, Jay; Gai, Wei; Hommelhoff, Peter; Huang, Yen-Chieh; Jing, Chunguang; McGuinness, Christopher; Palmer, Robert B.; Naranjo, Brian; Rosenzweig, James; Travish, Gil; Mizrahi, Amit; Schachter, Levi; Sears, Christopher; Werner, Gregory R.; Yoder, Rodney B.

    2014-10-01

    The use of infrared lasers to power optical-scale lithographically fabricated particle accelerators is a developing area of research that has garnered increasing interest in recent years. The physics and technology of this approach is reviewed, which is referred to as dielectric laser acceleration (DLA). In the DLA scheme operating at typical laser pulse lengths of 0.1 to 1 ps, the laser damage fluences for robust dielectric materials correspond to peak surface electric fields in the GV /m regime. The corresponding accelerating field enhancement represents a potential reduction in active length of the accelerator between 1 and 2 orders of magnitude. Power sources for DLA-based accelerators (lasers) are less costly than microwave sources (klystrons) for equivalent average power levels due to wider availability and private sector investment. Because of the high laser-to-particle coupling efficiency, required pulse energies are consistent with tabletop microJoule class lasers. Combined with the very high (MHz) repetition rates these lasers can provide, the DLA approach appears promising for a variety of applications, including future high-energy physics colliders, compact light sources, and portable medical scanners and radiative therapy machines.

  18. Laser pulse shaping for high gradient accelerators

    Science.gov (United States)

    Villa, F.; Anania, M. P.; Bellaveglia, M.; Bisesto, F.; Chiadroni, E.; Cianchi, A.; Curcio, A.; Galletti, M.; Di Giovenale, D.; Di Pirro, G.; Ferrario, M.; Gatti, G.; Moreno, M.; Petrarca, M.; Pompili, R.; Vaccarezza, C.

    2016-09-01

    In many high gradient accelerator schemes, i.e. with plasma or dielectric wakefield induced by particles, many electron pulses are required to drive the acceleration of one of them. Those electron bunches, that generally should have very short duration and low emittance, can be generated in photoinjectors driven by a train of laser pulses coming inside the same RF bucket. We present the system used to shape and characterize the laser pulses used in multibunch operations at Sparc_lab. Our system gives us control over the main parameter useful to produce a train of up to five high brightness bunches with tailored intensity and time distribution.

  19. Electron acceleration by a localized Bernstein mode

    Science.gov (United States)

    Kumar, Asheel

    2017-07-01

    An analytical framework for electron acceleration by an axially localized large amplitude electron Bernstein mode in a magnetized plasma is developed. The mode is localized due to plasma density profile or magnetic field profile and could be excited by launching an electron cyclotron wave from out side. A mildly pre-accelerated electron beam of finite Larmor radius resonantly interacts with the mode and gains axial energy as well as transverse energy. The scheme is suitable for producing electron beams of energy upto several MeV.

  20. Laser pulse shaping for high gradient accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Villa, F., E-mail: fabio.villa@lnf.infn.it [INFN-Laboratori Nazionali di Frascati, via E. Fermi 40, 00044 Frascati (Italy); Anania, M.P.; Bellaveglia, M. [INFN-Laboratori Nazionali di Frascati, via E. Fermi 40, 00044 Frascati (Italy); Bisesto, F. [INFN-Laboratori Nazionali di Frascati, via E. Fermi 40, 00044 Frascati (Italy); Università La Sapienza di Roma, Via A. Scarpa 14, Rome (Italy); Chiadroni, E. [INFN-Laboratori Nazionali di Frascati, via E. Fermi 40, 00044 Frascati (Italy); Cianchi, A. [INFN-Roma Tor Vergata and Università di Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome (Italy); Curcio, A.; Galletti, M.; Di Giovenale, D.; Di Pirro, G.; Ferrario, M.; Gatti, G. [INFN-Laboratori Nazionali di Frascati, via E. Fermi 40, 00044 Frascati (Italy); Moreno, M.; Petrarca, M. [Università La Sapienza di Roma, Via A. Scarpa 14, Rome (Italy); Pompili, R.; Vaccarezza, C. [INFN-Laboratori Nazionali di Frascati, via E. Fermi 40, 00044 Frascati (Italy)

    2016-09-01

    In many high gradient accelerator schemes, i.e. with plasma or dielectric wakefield induced by particles, many electron pulses are required to drive the acceleration of one of them. Those electron bunches, that generally should have very short duration and low emittance, can be generated in photoinjectors driven by a train of laser pulses coming inside the same RF bucket. We present the system used to shape and characterize the laser pulses used in multibunch operations at Sparc-lab. Our system gives us control over the main parameter useful to produce a train of up to five high brightness bunches with tailored intensity and time distribution.

  1. Plasma-based accelerator structures

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, Carl B. [Univ. of California, Berkeley, CA (United States)

    1999-12-01

    Plasma-based accelerators have the ability to sustain extremely large accelerating gradients, with possible high-energy physics applications. This dissertation further develops the theory of plasma-based accelerators by addressing three topics: the performance of a hollow plasma channel as an accelerating structure, the generation of ultrashort electron bunches, and the propagation of laser pulses is underdense plasmas.

  2. Uniform Acceleration in General Relativity

    CERN Document Server

    Friedman, Yaakov

    2016-01-01

    We extend de la Fuente and Romero's defining equation for uniform acceleration in a general curved spacetime from linear acceleration to the full Lorentz covariant uniform acceleration. In a flat spacetime background, we have explicit solutions. We use generalized Fermi-Walker transport to parallel transport the Frenet basis along the trajectory. In flat spacetime, we obtain velocity and acceleration transformations from a uniformly accelerated system to an inertial system. We obtain the time dilation between accelerated clocks. We apply our acceleration transformations to the motion of a charged particle in a constant electromagnetic field and recover the Lorentz-Abraham-Dirac equation.

  3. Cosmic Plasma Wakefield Acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Chen, P

    2004-04-26

    Recently we proposed a new cosmic acceleration mechanism which was based on the wakefields excited by the Alfven shocks in a relativistically owing plasma. In this paper we include some omitted details, and show that there exists a threshold condition for transparency below which the accelerating particle is collision-free and suffers little energy loss in the plasma medium. The stochastic encounters of the random accelerating-decelerating phases results in a power-law energy spectrum: f({epsilon}) {proportional_to} 1/{epsilon}{sup 2}. As an example, we discuss the possible production of super-GZK ultra high energy cosmic rays (UHECR) in the atmosphere of gamma ray bursts. The estimated event rate in our model agrees with that from UHECR observations.

  4. Superconducting Accelerator Magnets

    CERN Document Server

    Mess, K H; Wolff, S

    1996-01-01

    The main topic of the book are the superconducting dipole and quadrupole magnets needed in high-energy accelerators and storage rings for protons, antiprotons or heavy ions. The basic principles of low-temperature superconductivity are outlined with special emphasis on the effects which are relevant for accelerator magnets. Properties and fabrication methods of practical superconductors are described. Analytical methods for field calculation and multipole expansion are presented for coils without and with iron yoke. The effect of yoke saturation and geometric distortions on field quality is studied. Persistent magnetization currents in the superconductor and eddy currents the copper part of the cable are analyzed in detail and their influence on field quality and magnet performance is investigated. Superconductor stability, quench origins and propagation and magnet protection are addressed. Some important concepts of accelerator physics are introduced which are needed to appreciate the demanding requirements ...

  5. Particle accelerator physics

    CERN Document Server

    Wiedemann, Helmut

    2007-01-01

    Particle Accelerator Physics is an in-depth and comprehensive introduction to the field of high-energy particle acceleration and beam dynamics. Part I gathers the basic tools, recalling the essentials of electrostatics and electrodynamics as well as of particle dynamics in electromagnetic fields. Part II is an extensive primer in beam dynamics, followed in Part III by the introduction and description of the main beam parameters. Part IV is devoted to the treatment of perturbations in beam dynamics. Part V discusses the details of charged particle accleration. Part VI and Part VII introduce the more advanced topics of coupled beam dynamics and the description of very intense beams. Part VIII is an exhaustive treatment of radiation from accelerated charges and introduces important sources of coherent radiation such as synchrotrons and free-electron lasers. Part IX collects the appendices gathering useful mathematical and physical formulae, parameters and units. Solutions to many end-of-chapter problems are give...

  6. Proliferation Potential of Accelerator-Drive Systems: Feasibility Calculations

    Energy Technology Data Exchange (ETDEWEB)

    Riendeau, C.D.; Moses, D.L.; Olson, A.P.

    1998-11-01

    Accelerator-driven systems for fissile materials production have been proposed and studied since the early 1950s. Recent advances in beam power levels for small accelerators have raised the possibility that such use could be feasible for a potential proliferator. The objective of this study is to review the state of technology development for accelerator-driven spallation neutron sources and subcritical reactors. Energy and power requirements were calculated for a proton accelerator-driven neutron spallation source and subcritical reactors to produce a significant amount of fissile material--plutonium.

  7. Proton acceleration by circularly polarized traveling electromagnetic wave

    Directory of Open Access Journals (Sweden)

    Amol Holkundkar

    2012-09-01

    Full Text Available The acceleration of charged particles, producing collimated monoenergetic beams, over short distances holds the promise to offer new tools in medicine and diagnostics. Here, we consider a possible mechanism for accelerating protons to high energies by using a phase modulated circularly polarized electromagnetic wave propagating along a constant magnetic field. It is observed that a plane wave with dimensionless amplitude of 0.1 is capable to accelerate a 1 keV proton to 386 MeV under optimum conditions. Finally, we discuss possible limitations of the acceleration scheme.

  8. Staged electron laser accelerator (STELLA) experiment at brookhaven ATF

    Energy Technology Data Exchange (ETDEWEB)

    Pogorelsky, I.V.; Steenbergen, A. van; Gallardo, J.C. [Brookhaven National Lab., Upton, NY (United States)] [and others

    1998-03-01

    The STELLA experiment is being prepared at the BNL Accelerator Test Facility (STF). The goal of the experiment is to demonstrate quasi-monochromatic inverse Cherenkov acceleration (ICA) of electrons bunched to the laser wavelength period. Microbunches on the order of 2 {mu}m in length separated by 10.6 {mu}m will be produced using an inverse free electron laser (IFEL) accelerator driven by a CO{sub 2} laser. The design and simulations for two phases of this experiment including demonstration of 10 MeV and 100 MeV acceleration are presented. (author)

  9. Proton acceleration by circularly polarized traveling electromagnetic wave

    CERN Document Server

    Holkundkar, A; Marklund, M

    2012-01-01

    The acceleration of charged particles, producing collimated mono-energetic beams, over short distances holds the promise to offer new tools in medicine and diagnostics. Here, we consider a possible mechanism for accelerating protons to high energies by using a phase-modulated circularly polarized electromagnetic wave propagating along a constant magnetic field. It is observed that a plane wave with dimensionless amplitude of 0.1 is capable to accelerate a 1 KeV proton to 386 MeV under optimum conditions. Finally we discuss possible limitations of the acceleration scheme.

  10. Studies of accelerated compact toruses

    Energy Technology Data Exchange (ETDEWEB)

    Hartman, C.W.; Eddleman, J.; Hammer, J.H.

    1983-01-04

    In an earlier publication we considered acceleration of plasma rings (Compact Torus). Several possible accelerator configurations were suggested and the possibility of focusing the accelerated rings was discussed. In this paper we consider one scheme, acceleration of a ring between coaxial electrodes by a B/sub theta/ field as in a coaxial rail-gun. If the electrodes are conical, a ring accelerated towards the apex of the cone undergoes self-similar compression (focusing) during acceleration. Because the allowable acceleration force, F/sub a/ = kappaU/sub m//R where (kappa < 1), increases as R/sup -2/, the accelerating distance for conical electrodes is considerably shortened over that required for coaxial electrodes. In either case, however, since the accelerating flux can expand as the ring moves, most of the accelerating field energy can be converted into kinetic energy of the ring leading to high efficiency.

  11. Microelectromechanical acceleration-sensing apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Robb M. (Albuquerque, NM); Shul, Randy J. (Albuquerque, NM); Polosky, Marc A. (Albuquerque, NM); Hoke, Darren A. (Albuquerque, NM); Vernon, George E. (Rio Rancho, NM)

    2006-12-12

    An acceleration-sensing apparatus is disclosed which includes a moveable shuttle (i.e. a suspended mass) and a latch for capturing and holding the shuttle when an acceleration event is sensed above a predetermined threshold level. The acceleration-sensing apparatus provides a switch closure upon sensing the acceleration event and remains latched in place thereafter. Examples of the acceleration-sensing apparatus are provided which are responsive to an acceleration component in a single direction (i.e. a single-sided device) or to two oppositely-directed acceleration components (i.e. a dual-sided device). A two-stage acceleration-sensing apparatus is also disclosed which can sense two acceleration events separated in time. The acceleration-sensing apparatus of the present invention has applications, for example, in an automotive airbag deployment system.

  12. Deuterium accelerator experiments for APT.

    Energy Technology Data Exchange (ETDEWEB)

    Causey, Rion A. (Sandia National Laboratories, Livermore, CA); Hertz, Kristin L. (Sandia National Laboratories, Livermore, CA); Cowgill, Donald F. (Sandia National Laboratories, Livermore, CA)

    2005-08-01

    Sandia National Laboratories in California initiated an experimental program to determine whether tritium retention in the tube walls and permeation through the tubes into the surrounding coolant water would be a problem for the Accelerator Production of Tritium (APT), and to find ways to mitigate the problem, if it existed. Significant holdup in the tube walls would limit the ability of APT to meet its production goals, and high levels of permeation would require a costly cleanup system for the cooling water. To simulate tritium implantation, a 200 keV accelerator was used to implant deuterium into Al 6061-T and SS3 16L samples at temperatures and particle fluxes appropriate for APT, for times varying between one week and five months. The implanted samples were characterized to determine the deuterium retention and Permeation. During the implantation, the D(d,p)T nuclear reaction was used to monitor the build-up of deuterium in the implant region of the samples. These experiments increased in sophistication, from mono-energetic deuteron implants to multi-energetic deuteron and proton implants, to more accurately reproduce the conditions expected in APT. Micron-thick copper, nickel, and anodized aluminum coatings were applied to the front surface of the samples (inside of the APT walls) in an attempt to lower retention and permeation. The reduction in both retention and permeation produced by the nickel coatings, and the ability to apply them to the inside of the APT tubes, indicate that both nickel-coated Al 6061-T6 and nickel-coated SS3 16L tubes would be effective for use in APT. The results of this work were submitted to the Accelerator Production of Tritium project in document number TPO-E29-Z-TNS-X-00050, APT-MP-01-17.

  13. Accelerated Adaptive MGS Phase Retrieval

    Science.gov (United States)

    Lam, Raymond K.; Ohara, Catherine M.; Green, Joseph J.; Bikkannavar, Siddarayappa A.; Basinger, Scott A.; Redding, David C.; Shi, Fang

    2011-01-01

    The Modified Gerchberg-Saxton (MGS) algorithm is an image-based wavefront-sensing method that can turn any science instrument focal plane into a wavefront sensor. MGS characterizes optical systems by estimating the wavefront errors in the exit pupil using only intensity images of a star or other point source of light. This innovative implementation of MGS significantly accelerates the MGS phase retrieval algorithm by using stream-processing hardware on conventional graphics cards. Stream processing is a relatively new, yet powerful, paradigm to allow parallel processing of certain applications that apply single instructions to multiple data (SIMD). These stream processors are designed specifically to support large-scale parallel computing on a single graphics chip. Computationally intensive algorithms, such as the Fast Fourier Transform (FFT), are particularly well suited for this computing environment. This high-speed version of MGS exploits commercially available hardware to accomplish the same objective in a fraction of the original time. The exploit involves performing matrix calculations in nVidia graphic cards. The graphical processor unit (GPU) is hardware that is specialized for computationally intensive, highly parallel computation. From the software perspective, a parallel programming model is used, called CUDA, to transparently scale multicore parallelism in hardware. This technology gives computationally intensive applications access to the processing power of the nVidia GPUs through a C/C++ programming interface. The AAMGS (Accelerated Adaptive MGS) software takes advantage of these advanced technologies, to accelerate the optical phase error characterization. With a single PC that contains four nVidia GTX-280 graphic cards, the new implementation can process four images simultaneously to produce a JWST (James Webb Space Telescope) wavefront measurement 60 times faster than the previous code.

  14. Work plan for improving the DARWIN2.3 depleted material balance calculation of nuclides of interest for the fuel cycle

    Science.gov (United States)

    Rizzo, Axel; Vaglio-Gaudard, Claire; Martin, Julie-Fiona; Noguère, Gilles; Eschbach, Romain

    2017-09-01

    DARWIN2.3 is the reference package used for fuel cycle applications in France. It solves the Boltzmann and Bateman equations in a coupling way, with the European JEFF-3.1.1 nuclear data library, to compute the fuel cycle values of interest. It includes both deterministic transport codes APOLLO2 (for light water reactors) and ERANOS2 (for fast reactors), and the DARWIN/PEPIN2 depletion code, each of them being developed by CEA/DEN with the support of its industrial partners. The DARWIN2.3 package has been experimentally validated for pressurized and boiling water reactors, as well as for sodium fast reactors; this experimental validation relies on the analysis of post-irradiation experiments (PIE). The DARWIN2.3 experimental validation work points out some isotopes for which the depleted concentration calculation can be improved. Some other nuclides have no available experimental validation, and their concentration calculation uncertainty is provided by the propagation of a priori nuclear data uncertainties. This paper describes the work plan of studies initiated this year to improve the accuracy of the DARWIN2.3 depleted material balance calculation concerning some nuclides of interest for the fuel cycle.

  15. Applying ISO 11929:2010 Standard to detection limit calculation in least-squares based multi-nuclide gamma-ray spectrum evaluation

    Science.gov (United States)

    Kanisch, G.

    2017-05-01

    The concepts of ISO 11929 (2010) are applied to evaluation of radionuclide activities from more complex multi-nuclide gamma-ray spectra. From net peak areas estimated by peak fitting, activities and their standard uncertainties are calculated by weighted linear least-squares method with an additional step, where uncertainties of the design matrix elements are taken into account. A numerical treatment of the standard's uncertainty function, based on ISO 11929 Annex C.5, leads to a procedure for deriving decision threshold and detection limit values. The methods shown allow resolving interferences between radionuclide activities also in case of calculating detection limits where they can improve the latter by including more than one gamma line per radionuclide. The co"mmon single nuclide weighted mean is extended to an interference-corrected (generalized) weighted mean, which, combined with the least-squares method, allows faster detection limit calculations. In addition, a new grouped uncertainty budget was inferred, which for each radionuclide gives uncertainty budgets from seven main variables, such as net count rates, peak efficiencies, gamma emission intensities and others; grouping refers to summation over lists of peaks per radionuclide.

  16. A New Approach for the Determination of Dose Rate and Radioactivity for Detected Gamma Nuclides Using an Environmental Radiation Monitor Based on an NaI(Tl) Detector.

    Science.gov (United States)

    Ji, Young-Yong; Kim, Chang-Jong; Lim, Kyo-Sun; Lee, Wanno; Chang, Hyon-Sock; Chung, Kun Ho

    2017-10-01

    To expand the application of dose rate spectroscopy to the environment, the method using an environmental radiation monitor (ERM) based on a 3' × 3' NaI(Tl) detector was used to perform real-time monitoring of the dose rate and radioactivity for detected gamma nuclides in the ground around an ERM. Full-energy absorption peaks in the energy spectrum for dose rate were first identified to calculate the individual dose rates of Bi, Ac, Tl, and K distributed in the ground through interference correction because of the finite energy resolution of the NaI(Tl) detector used in an ERM. The radioactivity of the four natural radionuclides was then calculated from the in situ calibration factor-that is, the dose rate per unit curie-of the used ERM for the geometry of the ground in infinite half-space, which was theoretically estimated by Monte Carlo simulation. By an intercomparison using a portable HPGe and samples taken from the ground around an ERM, this method to calculate the dose rate and radioactivity of four nuclides using an ERM was experimentally verified and finally applied to remotely monitor them in real-time in the area in which the ERM had been installed.

  17. Total Cross Sections as a Surrogate for Neutron Capture: An Opportunity to Accurately Constrain (n,γ) Cross Sections for Nuclides Beyond the Reach of Direct Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Koehler, Paul E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-03-05

    There are many (n,γ) cross sections of great interest to radiochemical diagnostics and to nuclear astrophysics which are beyond the reach of current measurement techniques, and likely to remain so for the foreseeable future. In contrast, total neutron cross sections currently are feasible for many of these nuclides and provide almost all the information needed to accurately calculate the (n,γ) cross sections via the nuclear statistical model (NSM). I demonstrate this for the case of 151Sm; NSM calculations constrained using average resonance parameters obtained from total cross section measurements made in 1975, are in excellent agreement with recent 151Sm (n,γ) measurements across a wide range of energy. Furthermore, I demonstrate through simulations that total cross section measurements can be made at the Manuel Lujan Jr. Neutron Scattering Center at the Los Alamos Neutron Science Center for samples as small as 10μg. Samples of this size should be attainable for many nuclides of interest. Finally, I estimate that over half of the radionuclides identified ~20 years ago as having (n,γ) cross sections of importance to s-process nucleosynthesis studies (24/43) and radiochemical diagnostics (11/19), almost none of which have been measured, can be constrained using this technique.

  18. Short-lived radioactive nuclides in meteorites and early solar system processes; Radioactivites eteintes a courtes periodes dans les meteorites et evolution precoce du systeme solaire

    Energy Technology Data Exchange (ETDEWEB)

    Chaussidon, M. [Centre de Recherches Petrographiques et Geochimiques, CRPG-CNRS, 54 - Vandoeuvre-les-Nancy (France); Gounelle, M. [Museum National d' Histoire Naturelle, Lab. d' Etude de la Matiere Extra-Terrestre (LEME), 75 - Paris (France)

    2007-11-15

    Now extinct, short-lived radioactive nuclides, such as {sup 7}Be (T{sub 1/2} = 53 days), {sup 10}Be (T{sub 1/2} = 1.5 Ma), {sup 26}Al (T{sub 1/2} = 0.74 Ma), {sup 36}Cl (T{sub 1/2} = 0.3 Ma), {sup 41}Ca (T{sub 1/2} = 0.1 Ma), {sup 53}Mn (T{sub 1/2} = 3.7 Ma) and {sup 60}Fe (T{sub 1/2} = 1.5 Ma), were present in the proto-solar nebula when the various components of meteorites formed. The presence of these radioactive isotopes requires a 'last-minute' origin, either nucleosynthesis in a massive star dying close in space and time to the nascent solar system or production by local irradiation of part of the proto-solar disk by high-energy solar cosmic rays. In this review, we list: (i) the different observations indicating the existence of multiple origins for short-lived radioactive nuclides, namely {sup 7}Be, {sup 10}Be and {sup 36}Cl for irradiation scenario and {sup 60}Fe for injection scenario; (ii) the constraints that exist on their distribution (homogeneous or heterogeneous) in the accretion disk; (iii) the constraints they brought on the timescales of nebular processes (from Ca-Al-rich inclusions to chondrules) and of the accretion and differentiation of planetesimals. (authors)

  19. Accelerating time to benefit

    DEFF Research Database (Denmark)

    Svejvig, Per; Geraldi, Joana; Grex, Sara

    Despite the ubiquitous pressure for speed, our approaches to accelerate projects remain constrained to the old-fashioned understanding of the project as a vehicle to deliver products and services, not value. This article explores an attempt to accelerate time to benefit. We describe and deconstruct...... of the time. Although all cases valued speed and speed to benefit, and implemented most practices proposed by the methodology, only three of the five projects were more successful in decreasing time to speed. Based on a multi-case study comparison between these five different projects and their respective...

  20. Accelerating News Issue 4

    CERN Document Server

    Szeberenyi, A; Wildner, E

    2012-01-01

    In this winter issue, we are very pleased to announce the approval of EuCARD-2 by the European Commission. We look at the conclusions of EUROnu in proposing future neutrino facilities at CERN, a new milestone reached by CLIC and progress on the SPARC upgrade using C-band technology. We also report on recent events: second Joint HiLumi LHC-LARP Annual Meeting and workshop on Superconducting technologies for the Next Generation of Accelerators aiming at closer collaboration with industry. The launch of the Accelerators for Society brochure is also highlighted.

  1. Shielding high energy accelerators

    CERN Document Server

    Stevenson, Graham Roger

    2001-01-01

    After introducing the subject of shielding high energy accelerators, point source, line-of-sight models, and in particular the Moyer model. are discussed. Their use in the shielding of proton and electron accelerators is demonstrated and their limitations noted. especially in relation to shielding in the forward direction provided by large, flat walls. The limitations of reducing problems to those using it cylindrical geometry description are stressed. Finally the use of different estimators for predicting dose is discussed. It is suggested that dose calculated from track-length estimators will generally give the most satisfactory estimate. (9 refs).

  2. Accelerator technical design report for high-intensity proton accelerator facility project, J-PARC

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-03-01

    This report presents the detail of the technical design of the accelerators for the High-Intensity Proton Accelerator Facility Project, J-PARC. The accelerator complex comprises a 400-MeV room-temperature linac (600-MeV superconducting linac), 3-GeV rapid-cycling synchrotron (RCS), and a 50-GeV synchrotron (MR). The 400-MeV beam is injected to the RCS, being accelerated to 3 GEV. The 1-MW beam thus produced is guided to the Materials Life Science Experimental Facility, with both the pulsed spallation neutron source and muon source. A part of the beam is transported to the MR, which provides the 0.75-MW beam to either the Nuclear and Fundamental Particle Experimental Facility or the Neutrino Production Target. On the other hand, the beam accelerated to 600 MeV by the superconducting linac is used for the Nuclear Waster Transmutation Experiment. In this way, this facility is unique, being multipurpose one, including many new inventions and Research and Development Results. This report is based upon the accomplishments made by the Accelerator Group and others of the Project Team, which is organized on the basis of the Agreement between JAERI and KEK on the Construction and Research and Development of the High-Intensity Proton Accelerator Facility. (author)

  3. Cosmogenic isotopes and neo-tectonics. Active tectonics and cosmic radiations: in situ generated cosmogenic nuclides; Isotopes cosmogeniques et neotectonique. Tectonique active et rayons cosmiques: les nucleides cosmogeniques produits in situ

    Energy Technology Data Exchange (ETDEWEB)

    Siame, L.; Braucher, R.; Bourles, D.; Derrieux, F

    2009-06-15

    In situ generated cosmogenic nuclides ({sup 10}Be, {sup 26}Al, {sup 36}Cl) allow to analyse and determine the velocity in landscape changes. The build-up of cosmogenic nuclides in surface rocks submitted to cosmic radiations is proportional to the geomorphological stability of the exposed surfaces. Thus the concentration of in situ generated cosmogenic nuclides depends on the duration of the exposure and on the denudation rate. In some favorable circumstances the method allows to estimate the age of surface exposure. For a given sample at a given depth, an infinity of time-denudation solutions can be calculated to explained the measured concentration. The use of multiple samples taken at different depths allows to solve this mathematical problem and to obtain a unique solution. (J.S.)

  4. Detecting Energy Modulation in a Dielectric Laser Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Lukaczyk, Louis [Univ. of Virginia, Charlottesville, VA (United States)

    2015-08-21

    The Dielectric Laser Acceleration group at SLAC uses micro-fabricated dielectric grating structures and conventional infrared lasers to accelerator electrons. These structures have been estimated to produce an accelerating gradient up to 2 orders of magnitude greater than that produced by conventional RF accelerators. The success of the experiment depends on both the laser damage threshold of the structure and the timing overlap of femtosecond duration laser pulses with the electron bunch. In recent dielectric laser acceleration experiments, the laser pulse was shorter both temporally and spatially than the electron bunch. As a result, the laser is theorized to have interacted with only a small portion of the electron bunch. The detection of this phenomenon, referred to as partial population modulation, required a new approach to the data analysis of the electron energy spectra. A fitting function was designed to separate the accelerated electron population from the un-accelerated electron population. The approach was unsuccessful in detecting acceleration in the partial population modulation data. However, the fitting functions provide an excellent figure of merit for previous data known to contain signatures of acceleration.

  5. Staging and laser acceleration of ions in underdense plasma

    Science.gov (United States)

    Ting, Antonio; Hafizi, Bahman; Helle, Michael; Chen, Yu-Hsin; Gordon, Daniel; Kaganovich, Dmitri; Polyanskiy, Mikhail; Pogorelsky, Igor; Babzien, Markus; Miao, Chenlong; Dover, Nicholas; Najmudin, Zulfikar; Ettlinger, Oliver

    2017-03-01

    Accelerating ions from rest in a plasma requires extra considerations because of their heavy mass. Low phase velocity fields or quasi-electrostatic fields are often necessary, either by operating above or near the critical density or by applying other slow wave generating mechanisms. Solid targets have been a favorite and have generated many good results. High density gas targets have also been reported to produce energetic ions. It is interesting to consider acceleration of ions in laser-driven plasma configurations that will potentially allow continuous acceleration in multiple consecutive stages. The plasma will be derived from gaseous targets, producing plasma densities slightly below the critical plasma density (underdense) for the driving laser. Such a plasma is experimentally robust, being repeatable and relatively transparent to externally injected ions from a previous stage. When optimized, multiple stages of this underdense laser plasma acceleration mechanism can progressively accelerate the ions to a high final energy. For a light mass ion such as the proton, relativistic velocities could be reached, making it suitable for further acceleration by high phase velocity plasma accelerators to energies appropriate for High Energy Physics applications. Negatively charged ions such as antiprotons could be similarly accelerated in this multi-staged ion acceleration scheme.

  6. Nanostructured targets for TNSA laser ion acceleration

    Directory of Open Access Journals (Sweden)

    Torrisi Lorenzo

    2016-06-01

    Full Text Available Nanostructured targets, based on hydrogenated polymers with embedded nanostructures, were prepared as thin micrometric foils for high-intensity laser irradiation in TNSA regime to produce high-ion acceleration. Experiments were performed at the PALS facility, in Prague, by using 1315 nm wavelength, 300 ps pulse duration and an intensity of 1016 W/cm2 and at the IPPLM, in Warsaw, by using 800 nm wavelength, 40 fs pulse duration, and an intensity of 1019 W/cm2. Forward plasma diagnostic mainly uses SiC detectors and ion collectors in time of flight (TOF configuration. At these intensities, ions can be accelerated at energies above 1 MeV per nucleon. In presence of Au nanoparticles, and/or under particular irradiation conditions, effects of resonant absorption can induce ion acceleration enhancement up to values of the order of 4 MeV per nucleon.

  7. Evidence for particle acceleration during magnetospheric substorms

    Science.gov (United States)

    Lopez, Ramon E.; Baker, Daniel N.

    1994-01-01

    Magnetospheric substorms represent the episodic dissipation of energy stored in the geomagnetic tail that was previously extracted from the solar wind. This energy release produces activity throughout the entire magnetosphere-ionosphere system, and it results in a wide variety of phenomena such as auroral intensifications and the generation of new current systems. All of these phenomena involve the acceleration of particles, sometimes up to several MeV. We present a brief overview of substorm phenomenology. We then review some of the evidence for particle acceleration in Earth's magnetosphere during substorms. Such in-situ observations in this most accessible of all cosmic plasma domains may hold important clues to understanding acceleration processes in more distant astrophysical systems.

  8. Incineration by accelerator; Incineration par accelerateur

    Energy Technology Data Exchange (ETDEWEB)

    Cribier, M.; FIoni, G.; Legrain, R.; Lelievre, F.; Leray, S.; Pluquet, A.; Safa, H.; Spiro, M.; Terrien, Y.; Veyssiere, Ch.

    1997-01-01

    The use MOX fuel allows to hope a stabilization of plutonium production around 500 tons for the French park. In return, the flow of minor actinides is increased to several tons. INCA (INCineration by Accelerator), dedicated instrument, would allow to transmute several tons of americium, curium and neptunium. It could be able to reduce nuclear waste in the case of stopping nuclear energy use. This project needs: a protons accelerator of 1 GeV at high intensity ( 50 m A), a window separating the accelerator vacuum from the reactor, a spallation target able to produce 30 neutrons by incident proton, an incineration volume where a part of fast neutrons around the target are recovered, and a thermal part in periphery with flows at 2.10 {sup 15} n/cm{sup 2}.s; a chemical separation of elements burning in thermal (americium) from the elements needing a flow of fast neutrons. (N.C.). 28 refs.

  9. Target and accelerator developments at CTI

    Science.gov (United States)

    Alvord, C. W.; Mendez, A. J.; Wittner, D. E.

    2001-07-01

    The accelerator products marketed by CTI have exclusively focused on proton-only, low energy (11 MeV) designs. This choice best suited the research customer, interested in producing several doses a day of a variety of positron emitting compounds. The PET cyclotron market has evolved into a high output, cost driven, competitive radiotracer production environment. A thoughtful analysis of the choices of energy and particle reveals that an 11 MeV proton accelerator outfitted with target changers and automated target loading and unloading equipment is still the best choice for FDG distribution. However technological innovations are required to face the challenges of the rapidly growing PET radiotracer business. Modifications to the CTI line of accelerators developed to face this evolving need will be presented.

  10. Awakening the potential of plasma acceleration

    CERN Multimedia

    Katarina Anthony

    2014-01-01

    Civil engineering has begun for the new AWAKE experiment, which looks to push the boundaries of particle acceleration. This proof-of-principle experiment will harness the power of wakefields generated by proton beams in plasma cells, producing accelerator gradients hundreds of times higher than those used in current RF cavities.   Civil engineering works are currently ongoing at the AWAKE facility. As one of CERN's accelerator R&D experiments, the AWAKE project is rather unique. Like all of CERN's experiments, AWAKE is a collaborative endeavour with institutes and organisations participating around the world. "But unlike fixed-target experiments, where the users take over once CERN has delivered the facility, in AWAKE, the synchronised proton, electron and laser beams provided by CERN are an integral part of the experiment," explains Edda Gschwendtner, CERN AWAKE project leader. "So, of course, CERN's involvement in the project goes well...

  11. RF linear accelerators for medical and industrial applications

    CERN Document Server

    Hanna, Samy

    2012-01-01

    This unique resource offers you a clear overview of medical and industrial accelerators. Using minimal mathematics, this book focuses on offering thorough explanations of basic concepts surrounding the operation of accelerators. you find well illustrated discussions designed to help you use accelerator-based systems in a safer, more productive, and more reliable manner.This practical book details the manufacturing process for producing accelerators for medical and industrial applications. You become knowledgeable about the commonly encountered real-world manufacturing issues and potential sources of defects which help you avoid costly production problems. From principles of operation and the role of accelerators in cancer radiation therapy, to manufacturing techniques and future trends in accelerator design and applications, this easy-to-comprehend volume quickly brings you up-to-speed with the critical concepts you need to understand for your work in the field.

  12. Combined generating-accelerating buncher for compact linear accelerators

    Science.gov (United States)

    Savin, E. A.; Matsievskiy, S. V.; Sobenin, N. P.; Sokolov, I. D.; Zavadtsev, A. A.

    2016-09-01

    Described in the previous article [1] method of the power extraction from the modulated electron beam has been applied to the compact standing wave electron linear accelerator feeding system, which doesnt require any connection waveguides between the power source and the accelerator itself [2]. Generating and accelerating bunches meet in the hybrid accelerating cell operating at TM020 mode, thus the accelerating module is placed on the axis of the generating module, which consists from the pulsed high voltage electron sources and electrons dumps. This combination makes the accelerator very compact in size which is very valuable for the modern applications such as portable inspection sources. Simulations and geometry cold tests are presented.

  13. The CERN accelerator complex

    CERN Multimedia

    Christiane Lefèvre

    2008-01-01

    The LHC is the last ring (dark grey line) in a complex chain of particle accelerators. The smaller machines are used in a chain to help boost the particles to their final energies and provide beams to a whole set of smaller experiments, which also aim to uncover the mysteries of the Universe.

  14. The CERN Accelerator School

    CERN Multimedia

    2016-01-01

      Introduction to accelerator physics This course will take place in Istanbul, Turkey, from 18 to 30 September 2016. It is now open for registration, and further information can be found here: http://cas.web.cern.ch/cas/Turkey-2016/Turkey-advert.html

  15. The CERN Accelerator School

    CERN Multimedia

    2016-01-01

    Introduction to accelerator physics This course will take place in Budapest, Hungary, from 2 to 14 October 2016. It is now open for registration and further information can be found at: http://cas.web.cern.ch/cas/Hungary2016/Hungary-advert.html and http://indico.cern.ch/event/532397/.

  16. The CERN accelerator complex

    CERN Multimedia

    De Melis, Cinzia

    2016-01-01

    The LHC is the last ring (dark blue line) in a complex chain of particle accelerators. The smaller machines are used in a chain to help boost the particles to their final energies and provide beams to a whole set of smaller experiments, which also aim to uncover the mysteries of the Universe.

  17. Acceleration and Special Relativity

    CERN Document Server

    Yahalomi, E M

    2000-01-01

    The integration of acceleration over time before reaching the uniformvelocity turns out to be the source of all the special relativity effects. Itexplains physical phenomena like clocks comparisons. The equations forspace-time, mass and energy are presented. This phenomenon complements theexplanation for the twins paradox. A Universal reference frame is obtained.

  18. Prospects for Accelerator Technology

    Science.gov (United States)

    Todd, Alan

    2011-02-01

    Accelerator technology today is a greater than US$5 billion per annum business. Development of higher-performance technology with improved reliability that delivers reduced system size and life cycle cost is expected to significantly increase the total accelerator technology market and open up new application sales. Potential future directions are identified and pitfalls in new market penetration are considered. Both of the present big market segments, medical radiation therapy units and semiconductor ion implanters, are approaching the "maturity" phase of their product cycles, where incremental development rather than paradigm shifts is the norm, but they should continue to dominate commercial sales for some time. It is anticipated that large discovery-science accelerators will continue to provide a specialty market beset by the unpredictable cycles resulting from the scale of the projects themselves, coupled with external political and economic drivers. Although fraught with differing market entry difficulties, the security and environmental markets, together with new, as yet unrealized, industrial material processing applications, are expected to provide the bulk of future commercial accelerator technology growth.

  19. The CERN accelerator complex

    CERN Multimedia

    Haffner, Julie

    2013-01-01

    The LHC is the last ring (dark grey line) in a complex chain of particle accelerators. The smaller machines are used in a chain to help boost the particles to their final energies and provide beams to a whole set of smaller experiments, which also aim to uncover the mysteries of the Universe.

  20. SPS accelerating cavity

    CERN Multimedia

    1980-01-01

    One of the SPS acceleration cavities (200 MHz, travelling wave structure). On the ceiling one sees the coaxial transmission line which feeds the power from the amplifier, located in a surface building above, to the upstream end of the cavity. See 7603195 for more details, 7411032 for the travelling wave structure, and also 8104138, 8302397.

  1. The CERN accelerator complex

    CERN Multimedia

    Mobs, Esma Anais

    2016-01-01

    The LHC is the last ring (dark blue line) in a complex chain of particle accelerators. The smaller machines are used in a chain to help boost the particles to their final energies and provide beams to a whole set of smaller experiments, which also aim to uncover the mysteries of the Universe.

  2. Atmospheric and accelerator neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Yoichiro [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo Higashi-Mozumi, Kamioka, Hida-City, Gifu 506-1205 (Japan)

    2006-05-15

    Results from the atmospheric neutrino measurements are presented. Evidence for the {nu}{sub {tau}} appearance in the atmospheric neutrino events was shown by statistical methods. The long baseline oscillation experiment using man-made neutrinos has confirmed the atmospheric neutrino oscillation. The future accelerator experiments are briefly discussed.

  3. SPS accelerating cavity

    CERN Multimedia

    CERN PhotoLab

    1981-01-01

    One of the SPS accelerating cavities (200 MHz, travelling wave structure). The power that is fed into the upstream end of the cavity is extracted at the downstream end and sent into a dump load. See 7603195 for more details, 7411032 for the travelling wave structure, and also 8011289, 8302397.

  4. Angular Accelerating White Light

    CSIR Research Space (South Africa)

    Dudley, Angela L

    2015-08-01

    Full Text Available Shaping XVI, 958104, San Diego, California, United States, 09 August 2015 Angular Accelerating White Light Angela Dudley*a,b, Christian Vetterc , Alexander Szameitc , and Andrew Forbesa,b a CSIR National Laser Centre, PO Box 395, Pretoria 0001...

  5. ANTIPROTONS PRODUCED IN SUPERNOVA REMNANTS

    Energy Technology Data Exchange (ETDEWEB)

    Berezhko, E. G.; Ksenofontov, L. T., E-mail: ksenofon@ikfia.sbras.ru [Yu. G. Shafer Institute of Cosmophysical Research and Aeronomy, 31 Lenin Avenue, 677891 Yakutsk (Russian Federation)

    2014-08-20

    We present the energy spectrum of an antiproton cosmic ray (CR) component calculated on the basis of the nonlinear kinetic model of CR production in supernova remnants (SNRs). The model includes the reacceleration of antiprotons already existing in the interstellar medium as well as the creation of antiprotons in nuclear collisions of accelerated protons with gas nuclei and their subsequent acceleration by SNR shocks. It is shown that the production of antiprotons in SNRs produces a considerable effect in their resultant energy spectrum, making it essentially flatter above 10 GeV so that the spectrum at TeV energies increases by a factor of 5. The calculated antiproton spectrum is consistent with the PAMELA data, which correspond to energies below 100 GeV. As a consistency check, we have also calculated within the same model the energy spectra of secondary nuclei and show that the measured boron-to-carbon ratio is consistent with the significant SNR contribution.

  6. AESS: Accelerated Exact Stochastic Simulation

    Science.gov (United States)

    Jenkins, David D.; Peterson, Gregory D.

    2011-12-01

    The Stochastic Simulation Algorithm (SSA) developed by Gillespie provides a powerful mechanism for exploring the behavior of chemical systems with small species populations or with important noise contributions. Gene circuit simulations for systems biology commonly employ the SSA method, as do ecological applications. This algorithm tends to be computationally expensive, so researchers seek an efficient implementation of SSA. In this program package, the Accelerated Exact Stochastic Simulation Algorithm (AESS) contains optimized implementations of Gillespie's SSA that improve the performance of individual simulation runs or ensembles of simulations used for sweeping parameters or to provide statistically significant results. Program summaryProgram title: AESS Catalogue identifier: AEJW_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEJW_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: University of Tennessee copyright agreement No. of lines in distributed program, including test data, etc.: 10 861 No. of bytes in distributed program, including test data, etc.: 394 631 Distribution format: tar.gz Programming language: C for processors, CUDA for NVIDIA GPUs Computer: Developed and tested on various x86 computers and NVIDIA C1060 Tesla and GTX 480 Fermi GPUs. The system targets x86 workstations, optionally with multicore processors or NVIDIA GPUs as accelerators. Operating system: Tested under Ubuntu Linux OS and CentOS 5.5 Linux OS Classification: 3, 16.12 Nature of problem: Simulation of chemical systems, particularly with low species populations, can be accurately performed using Gillespie's method of stochastic simulation. Numerous variations on the original stochastic simulation algorithm have been developed, including approaches that produce results with statistics that exactly match the chemical master equation (CME) as well as other approaches that approximate the CME. Solution

  7. Neurodegeneration in accelerated aging.

    Science.gov (United States)

    Scheibye-Knudsen, Moren

    2016-11-01

    The growing proportion of elderly people represents an increasing economic burden, not least because of age-associated diseases that pose a significant cost to the health service. Finding possible interventions to age-associated disorders therefore have wide ranging implications. A number of genetically defined accelerated aging diseases have been characterized that can aid in our understanding of aging. Interestingly, all these diseases are associated with defects in the maintenance of our genome. A subset of these disorders, Cockayne syndrome, Xeroderma pigmentosum group A and ataxia-telangiectasia, show neurological involvement reminiscent of what is seen in primary human mitochondrial diseases. Mitochondria are the power plants of the cells converting energy stored in oxygen, sugar, fat, and protein into ATP, the energetic currency of our body. Emerging evidence has linked this organelle to aging and finding mitochondrial dysfunction in accelerated aging disorders thereby strengthens the mitochondrial theory of aging. This theory states that an accumulation of damage to the mitochondria may underlie the process of aging. Indeed, it appears that some accelerated aging disorders that show neurodegeneration also have mitochondrial dysfunction. The mitochondrial alterations may be secondary to defects in nuclear DNA repair. Indeed, nuclear DNA damage may lead to increased energy consumption, alterations in mitochondrial ATP production and defects in mitochondrial recycling, a term called mitophagy. These changes may be caused by activation of poly-ADP-ribose-polymerase 1 (PARP1), an enzyme that responds to DNA damage. Upon activation PARP1 utilizes key metabolites that attenuate pathways that are normally protective for the cell. Notably, pharmacological inhibition of PARP1 or reconstitution of the metabolites rescues the changes caused by PARP1 hyperactivation and in many cases reverse the phenotypes associated with accelerated aging. This implies that modulation

  8. Producing Runaway Stars

    Science.gov (United States)

    Kohler, Susanna

    2016-07-01

    How are the hypervelocity stars weve observed in our galaxy produced? A recent study suggests that these escapees could be accelerated by a massive black hole in the center of the Large Magellanic Cloud.A Black Hole SlingshotSince their discovery in 2005, weve observed dozens of candidate hypervelocity stars stars whose velocity in the rest frame of our galaxy exceeds the local escape velocity of the Milky Way. These stars present a huge puzzle: how did they attain these enormous velocities?One potential explanation is known as the Hills mechanism. In this process, a stellar binary is disrupted by a close encounter with a massive black hole (like those thought to reside at the center of every galaxy). One member of the binary is flung out of the system as a result of the close encounter, potentially reaching very large velocities.A star-forming region known as LHA 120-N 11, located within the LMC. Some binary star systems within the LMC might experience close encounters with a possible massive black hole at the LMCs center. [ESA/NASA/Hubble]Blame the LMC?Usually, discussions of the Hills mechanism assume that Sagittarius A*, the supermassive black hole at the center of the Milky Way, is the object guilty of accelerating the hypervelocity stars weve observed. But what if the culprit isnt Sgr A*, but a massive black hole at the center of the Large Magellanic Cloud (LMC), one of the Milky Ways satellite galaxies?Though we dont yet have evidence of a massive black hole at the center of the LMC, the dwarf galaxy is large enough to potentially host one as large as 100,000 solar masses. Assuming that it does, two scientists at the University of Cambridge, Douglas Boubert and Wyn Evans, have now modeled how this black hole might tear apart binary star systems and fling hypervelocity stars around the Milky Way.Models for AccelerationBoubert and Evans determined that the LMCs hypothetical black hole could easily eject stars at ~100 km/s, which is the escape velocity of the

  9. The evolution of high energy accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Courant, E.D.

    1994-08-01

    Accelerators have been devised and built for two reasons: In the first place, by physicists who needed high energy particles in order to have a means to explore the interactions between particles that probe the fundamental elementary forces of nature. And conversely, sometimes accelerator builders produce new machines for higher energy than ever before just because it can be done, and then challenge potential users to make new discoveries with the new means at hand. These two approaches or motivations have gone hand in hand. This lecture traces how high energy particle accelerators have grown from tools used for esoteric small-scale experiments to the gigantic projects of today. So far all the really high-energy machines built and planned in the world--except the SLC--have been ring accelerators and storage rings using the strong-focusing method. But this method has not removed the energy limit, it has only pushed it higher. It would seem unlikely that one can go beyond the Large Hadron Collider (LHC)--but in fact a workshop was held in Sicily in November 1991, concerned with the question of extrapolating to 100 TeV. Other acceleration and beam-forming methods are now being discussed--collective fields, laser acceleration, wake-field accelerators etc., all aimed primarily at making linear colliders possible and more attractive than with present radiofrequency methods. So far it is not entirely clear which of these schemes will dominate particle physics in the future--maybe something that has not been thought of as yet.

  10. UV photolysis for accelerating pyridine biodegradation.

    Science.gov (United States)

    Zhang, Yongming; Chang, Ling; Yan, Ning; Tang, Yingxia; Liu, Rui; Rittmann, Bruce E

    2014-01-01

    Pyridine, a nitrogen-containing heterocyclic compound, is slowly biodegradable, and coupling biodegradation with UV photolysis is a potential means to accelerate its biotransformation and mineralization. The initial steps of pyridine biodegradation involve mono-oxygenation reactions that have molecular oxygen and an intracellular electron carrier as cosubstrates. We employed an internal circulation baffled biofilm reactor for pyridine biodegradation following three protocols: direct biodegradation (B), biodegradation after photolysis (P+B), and biodegradation with succinic acid added (B+S). Succinic acid was the main UV-photolysis product from pyridine, and its catabolic oxidation generates internal electron carriers that may accelerate the initial steps of pyridine biodegradation. Compared with direct biodegradation of pyridine (B), the removal rate for the same concentration of photolyzed pyridine (P+B) was higher by 15 to 43%, depending on the initial pyridine concentrations (increasing through the range of 130 to 310 mg/L). Adding succinic acid alone (B+S) gave results similar to P+B, which supports that succinic acid was the main agent for accelerating the pyridine biodegradation rate. In addition, protocols P+B and B+S were similar in terms of increasing pyridine mineralization over 10 h: 84% and 87%, respectively, which were higher than with protocol B (72%). The positive impact of succinic acid-whether added directly or produced via UV photolysis-confirms that its catabolism, which produced intracellular electron carriers, accelerated the initial steps of pyridine biotransformation.

  11. Nonlinear dynamics in particle accelerators

    CERN Document Server

    Dilão, Rui

    1996-01-01

    This book is an introductory course to accelerator physics at the level of graduate students. It has been written for a large audience which includes users of accelerator facilities, accelerator physicists and engineers, and undergraduates aiming to learn the basic principles of construction, operation and applications of accelerators.The new concepts of dynamical systems developed in the last twenty years give the theoretical setting to analyse the stability of particle beams in accelerator. In this book a common language to both accelerator physics and dynamical systems is integrated and dev

  12. Mass spectrometry with accelerators.

    Science.gov (United States)

    Litherland, A E; Zhao, X-L; Kieser, W E

    2011-01-01

    As one in a series of articles on Canadian contributions to mass spectrometry, this review begins with an outline of the history of accelerator mass spectrometry (AMS), noting roles played by researchers at three Canadian AMS laboratories. After a description of the unique features of AMS, three examples, (14)C, (10)Be, and (129)I are given to illustrate the methods. The capabilities of mass spectrometry have been extended by the addition of atomic isobar selection, molecular isobar attenuation, further ion acceleration, followed by ion detection and ion identification at essentially zero dark current or ion flux. This has been accomplished by exploiting the techniques and accelerators of atomic and nuclear physics. In 1939, the first principles of AMS were established using a cyclotron. In 1977 the selection of isobars in the ion source was established when it was shown that the (14)N(-) ion was very unstable, or extremely difficult to create, making a tandem electrostatic accelerator highly suitable for assisting the mass spectrometric measurement of the rare long-lived radioactive isotope (14)C in the environment. This observation, together with the large attenuation of the molecular isobars (13)CH(-) and (12)CH 2(-) during tandem acceleration and the observed very low background contamination from the ion source, was found to facilitate the mass spectrometry of (14)C to at least a level of (14)C/C ~ 6 × 10(-16), the equivalent of a radiocarbon age of 60,000 years. Tandem Accelerator Mass Spectrometry, or AMS, has now made possible the accurate radiocarbon dating of milligram-sized carbon samples by ion counting as well as dating and tracing with many other long-lived radioactive isotopes such as (10)Be, (26)Al, (36)Cl, and (129)I. The difficulty of obtaining large anion currents with low electron affinities and the difficulties of isobar separation, especially for the heavier mass ions, has prompted the use of molecular anions and the search for alternative

  13. Use of U-series nuclides to constrain sediments transfer-times in the alluvial plains: example of the Ganges and Bramaputra river system.

    Science.gov (United States)

    Chabaux, François; Granet, Mathieu; Blaes, Estelle; Stille, Peter; France-Lanord, Christian; Dosseto, Antony

    2010-05-01

    U-series nuclides have the potential to bring important information on the transfer time of sediments in the alluvial plains. This is a consequence of the dual property of these nuclides 1) to be fractionated during physical denudation and chemical weathering processes and 2) to have radioactive decay periods of the same order of magnitude as the time-scales of these processes (e.g. Chabaux et al., 2003b, 2008). We have illustrated such a potential with the analysis of U-series disequilibria in sediments collected in the Ganges and Bramaputra river basin. The approach relies on the analysis of U-series in river sediments collected along the streams. Indeed, as illustrated in Granet et al. (2007), in large alluvial plains where sediments are only transferred and not affected by additional inputs of new weathering products from fresh rocks, the intensity of 238U-234U-230Th disequilibria in river sediments will only depend on two parameters: (a) the duration of the transfer including the time spent in soils and in the river, and (b) the nature and the intensity of U-Th fractionations occurring in sediments during their transfer into alluvial plains. Recovering time information from the variation of U-Th disequilibria in such sediments requires therefore the use of realistic models accounting for the U-Th fractionation of sediments during their transfers into the plain. From the data, it is proposed for the Ganges and Bramaputra river sediments, that the main U-Th fractionation process is connected with the sediment weathering during their transit and storage in the plain. In this case the U-Th variation in sediments along the two main rivers lead to quite long sediment transfer time in the alluvial plains, of 100-150 ky for Bramaputra plain and of 400 or 500 ky for the Ganges river. Chabaux F., Riotte J., Dequincey O. (2003) U-Th-Ra fractionation during weathering and river transport, Rev Mineral. Geochem. 52, 533-576. Chabaux, F., Bourdon, B., Riotte, J., 2008. U

  14. A monolithic relativistic electron beam source based on a dielectric laser accelerator structure

    Energy Technology Data Exchange (ETDEWEB)

    McNeur, Josh; Carranza, Nestor; Travish, Gil; Yin Hairong; Yoder, Rodney [UCLA Dept. of Physics and Astronomy, Los Angeles, CA 90095 (United States); College of Physical Electronics, University of Electronic Science and Technology of China, Chengdu, Sichuan, 610054 (China); Manhattanville College, Physics Dept., 2900 Purchase St., Purchase, NY 10577 (United States)

    2012-12-21

    Work towards a monolithic device capable of producing relativistic particle beams within a cubic-centimeter is detailed. We will discuss the Micro-Accelerator Platform (MAP), an optical laser powered dielectric accelerator as the main building block of this chip-scale source along with a field enhanced emitter and a region for sub-relativistic acceleration.

  15. Electron acceleration by magnetic collapse during decoupling

    Science.gov (United States)

    Bennet, Euan D.; Potts, Hugh E.; Teodoro, Luis F. A.; Diver, Declan A.

    2014-12-01

    This paper identifies the non-equilibrium evolution of magnetic field structures at the onset of large-scale recombination of an inhomogeneously ionized plasma. The context for this is the Universe during the epoch of recombination. The electromagnetic treatment of this phase transition can produce energetic electrons scattered throughout the Universe, localized near the edges of magnetic domains. This is confirmed by a numerical simulation in which a magnetic domain is modelled as a uniform field region produced by a thin surrounding current sheet. Conduction currents sustaining the magnetic structure are removed as the charges comprising them combine into neutrals. The induced electric field accompanying the magnetic collapse is able to accelerate ambient stationary electrons (that is, electrons not participating in the current sheet) to energies of up to order 10keV. This is consistent with theoretical predictions. The localized electron acceleration leads to local imbalances of charge which has implications for charge separation in the early Universe.

  16. Pulsed power systems for the DARHT accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Downing, J.N.; Parsons, W.M.; Earley, L.M.; Melton, J.G.; Moir, D.C.; Carlson, R.L.; Barnes, G.A.; Builta, L.A.; Eversole, S.A.; Keel, G.I.; Rader, D.C.; Romero, J.A.; Shurter, R.P.

    1991-01-01

    The Dual-Axis Radiographic Hydro Test (DARHT) Facility is being designed to produce high-resolution flash radiographs of hydrodynamics experiments. Two 16- to 20-MeV linear induction accelerators (LIA), with an included angle of 90{degree}, are used to produce intense bremsstrahlung x-ray pulses of short duration (60-ns flat-top). Each accelerator has a 4-MeV electron source that injects an electron beam into a series of 250-kV induction cells. The three major pulsed-power systems are the injectors, the induction-cell pulsed-power (ICPP) units, and the ICPP trigger systems, and are discussed in this paper. 11 refs., 5 figs, 3 tabs.

  17. Code generation of RHIC accelerator device objects

    Energy Technology Data Exchange (ETDEWEB)

    Olsen, R.H.; Hoff, L.; Clifford, T.

    1995-12-01

    A RHIC Accelerator Device Object is an abstraction which provides a software view of a collection of collider control points known as parameters. A grammar has been defined which allows these parameters, along with code describing methods for acquiring and modifying them, to be specified efficiently in compact definition files. These definition files are processed to produce C++ source code. This source code is compiled to produce an object file which can be loaded into a front end computer. Each loaded object serves as an Accelerator Device Object class definition. The collider will be controlled by applications which set and get the parameters in instances of these classes using a suite of interface routines. Significant features of the grammar are described with details about the generated C++ code.

  18. Measuring the Acceleration of a Rigid Body

    Directory of Open Access Journals (Sweden)

    Peter G. Martin

    1998-01-01

    Full Text Available Two methods to measure the six-degree-of-freedom acceleration of a point on a rigid body are presented. The first, referred to as the periphery scheme, makes use of three clusters of accelerometers mounted orthogonal to each other and coincident with the axes of the point. One of the clusters consists of the three accelerometers attached to a cube-shaped triaxial angular rate sensor (ARS. The second method, called the compact cube scheme, uses a single 3-accelerometer/ARS cluster that may be mounted anywhere on the rigid body. During impact tests with an instrumented rigid body, both methods produced measurements that were highly correlated near the time of peak acceleration. Whereas the compact cube scheme was more economical and easier to implement, the periphery scheme produced results that were less disrupted by instrument signal errors and noisy environments.

  19. Acceleration of microparticle

    CERN Document Server

    Shibata, H

    2002-01-01

    A microparticle (dust) ion source has been installed at the high voltage terminal of the 3.75 MV single ended Van de Graaff electrostatic accelerator and a beam line for microparticle experiments has been build at High Fluence Irradiation Facility (HIT) of Research Center for Nuclear Science and Technology, the University of Tokyo. Microparticle acceleration has been successful in obtaining expected velocities of 1-20 km/s or more for micron or submicron sized particles. Development of in situ dust detectors and analyzers on board satellites and spacecraft in the expected mass and velocity range of micrometeoroids and investigation of hypervelocity impact phenomena by using time of flight mass spectrometry, impact flash or luminescence measurement and scanning electron or laser microscope observation for metals, ceramics, polymers and semiconductors bombarded by micron-sized particles were started three years ago. (author)

  20. Accelerated Parallel Texture Optimization

    Institute of Scientific and Technical Information of China (English)

    Hao-Da Huang; Xin Tong; Wen-Cheng Wang

    2007-01-01

    Texture optimization is a texture synthesis method that can efficiently reproduce various features of exemplar textures. However, its slow synthesis speed limits its usage in many interactive or real time applications. In this paper, we propose a parallel texture optimization algorithm to run on GPUs. In our algorithm, k-coherence search and principle component analysis (PCA) are used for hardware acceleration, and two acceleration techniques are further developed to speed up our GPU-based texture optimization. With a reasonable precomputation cost, the online synthesis speed of our algorithm is 4000+ times faster than that of the original texture optimization algorithm and thus our algorithm is capable of interactive applications. The advantages of the new scheme are demonstrated by applying it to interactive editing of flow-guided synthesis.