WorldWideScience

Sample records for mev isotope production

  1. Isotopic Production Cross Sections in Proton-Nucleus Collisions at 200 MeV

    CERN Document Server

    Machner, H; Baruth-Ram, K; Carter, J; Cowley, A A; Goldenbaum, F; Nangu, B M; Pilcher, J V; Sellschop, J P Friedel; Sideras-Haddad, E; Smit, F D; Spoelstra, B; Steyn, D

    2006-01-01

    Intermediate mass fragments (IMF) from the interaction of $^{27}$Al, $^{59}$Co and $^{197}$Au with 200 MeV protons were measured in an angular range from 20 degree to 120 degree in the laboratory system. The fragments, ranging from isotopes of helium up to isotopes of carbon, were isotopically resolved. Double differential cross sections, energy differential cross sections and total cross sections were extracted.

  2. Production of krypton and xenon isotopes in thick stony and iron targets isotropically irradiated with 1600 MeV protons

    CERN Document Server

    Gilabert, E; Lavielle, B; Leya, I; Michel, R; Neumann, S

    2002-01-01

    Two spherical targets made of gabbro with a radius of 25 cm and of steel with a radius of 10 cm were irradiated isotropically with 1600 MeV protons at the SATURNE synchrotron at Laboratoire National Saturne (LNS)/CEN Saclay, in order to simulate the production of nuclides in meteorites induced by galactic cosmic-ray protons in space. These experiments supply depth-dependent production rate data for a wide range of radioactive and stable isotopes in up to 28 target elements. In this paper, we report results for /sup 78/Kr, /sup 80-86/Kr isotopes in Rb, Sr, Y and Zr and for /sup 124/Xe, /sup 126/Xe, /sup 128-132/Xe, /sup 134/Xe, /sup 136/Xe isotopes in Ba and La. Krypton and xenon concentrations have been measured at different depths in the spheres by using conventional mass spectrometry. Based on Monte-Carlo techniques, theoretical production rates are calculated by folding depth-dependent spectra of primary and secondary protons and secondary neutrons with the excitation functions of the relevant nuclear reac...

  3. Targetry at the LANL 100 MeV isotope production facility: lessons learned from facility commissioning

    Energy Technology Data Exchange (ETDEWEB)

    Nortier, F. M. (Francois M.); Fassbender, M. E. (Michael E.); DeJohn, M.; Hamilton, V. T. (Virginia T.); Heaton, R. C. (Richard C.); Jamriska, David J.; Kitten, J. J. (Jason J.); Lenz, J. W.; Lowe, C. E.; Moddrell, C. F.; McCurdy, L. M. (Lisa M.); Peterson, E. J. (Eugene J.); Pitt, L. R. (Lawrence R.); Phillips, D. R. (Dennis R.); Salazar, L. L. (Louie L.); Smith, P. A. (Paul A.); Valdez, Frank O.

    2004-01-01

    The new Isotope Production Facility (IPF) at Los Alamos National Laboratory has been commissioned during the spring of 2004. Commissioning activities focused on the establishment of a radionuclide database, the review and approval of two specific target stack designs, and four trial runs with subsequent chemical processing and data analyses. This paper highlights some aspects of the facility and the targetry of the two approved target stacks used during the commissioning process. Since one niobium encapsulated gallium target developed a blister after the extended irradiation of 4 days, a further evaluation of the gallium targets is required. Beside this gallium target, no other target showed any sign of thermal failure. Considering the uncertainties involved, the production yields obtained for targets irradiated in the same energy slot are consistent for all three 'Prototype' stacks. A careful analysis of the temperature profile in the RbCl targets shows that energy shifts occur in the RbCl and Ga targets. Energy shifts are a result of density variations in the RbCl disk under bombardment. Thickness adjustments of targets in the prototype stack are required to ensure maximum production yields of {sup 82}Sr and {sup 68}Ge in the design energy windows. The {sup 68}Ge yields obtained are still consistently lower than the predicted yield value, which requires further investigation. After recalculation of the energy windows for the RbCl and Ga targets, the measured {sup 82}Sr production yields compare rather well with values predicted on the basis of evaluated experimental excitation function data.

  4. RADIONUCLIDE INVENTORY MANAGEMENT AT THE NEW 100 MeV ISOTOPE PRODUCTION FACILITY AT LANL

    Energy Technology Data Exchange (ETDEWEB)

    Fassbender, M.E.; Phillips, D.R.; Nortier, F.M.; Trellue, H.R.; Hamilton, V.T.; Heaton, R.C.; Jamriska, D.J.; Kitten, J.J.; Lowe, C.E.; McCurdy, L.M.; Pitt, L.R.; Salazar, L.L.; Sullivan, J.W.; Valdez, F.O.; Peterson, E.J.

    2004-10-03

    The Isotope Production Facility (IPF) at Los Alamos is operated on the authorization basis of a radiological facility with an inventory limit of a Category 3 Nuclear Facility. For the commissioning of IPF, a ''dummy'' target stack containing Zn, Nb and Al disks, and a ''prototype'' stack were irradiated with a proton beam. The ''prototype'' stack contained two pressed RbCl disks, encapsulated in stainless steel, and a Ga metal target. Typical ''prototype'' stack beam parameters were 88.9 {micro}A, 101.3 h. Operation procedures require the projection of all generated radionuclide activities. This is mandatory in order to determine both maximum beam current and maximum beam exposure time. The Monte Carlo code MCNPX and the burn-up code CINDER90 were used to determine maximum beam parameters prior to irradiation. After irradiation, activity estimates were calculated assuming actual average beam parameters. They were entered into an online inventory database, and were later, after chemical separation and radioactive assays, replaced by experimental values. A comparison of ''prototype'' stack experimental yield data to Monte Carlo calculation results showed that the computer codes provide realistic, conservative estimates.

  5. Production of neutron-rich isotopes by cold fragmentation in the reaction {sup 197}Au + Be at 950 A MeV

    Energy Technology Data Exchange (ETDEWEB)

    Benlliure, J.; Pereira, J. [Universidad de Santiago de Compostela (Spain)]|[Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Schmidt, K.H.; Cortina-Gil, D.; Enqvist, T.; Heinz, A.; Junghans, A.R. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Farget, F. [Institut de Physique Nucleaire, 91 - Orsay (France); Taieb, J. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany)]|[Institut de Physique Nucleaire, 91 - Orsay (France)

    1999-09-01

    The production cross sections and longitudinal-momentum distributions of very neutron-rich isotopes have been investigated in the fragmentation of a 950 A MeV {sup 179}Au beam in a beryllium target. Seven new isotopes ({sup 193}Re, {sup 194}Re, {sup 191}W, {sup 192}W, {sup 189}Ta, {sup 187}Hf and {sup 188}Hf) and the five-proton-removal channel were observed for the first time. The reaction mechanism leading to the formation of these very neutron-rich isotopes is explained in terms of the cold-fragmentation process. An analytical model describing this reaction mechanism is presented. (orig.)

  6. Production of neutron-rich copper isotopes in 30-MeV proton-induced fission of sup 2 sup 3 sup 8 U

    CERN Document Server

    Kruglov, K; Bruyneel, B; Dean, S S; Franchoo, S; Huyse, M; Kudryavtsev, Y; Müller, W F; Prasad, N V S; Raabe, R; Reusen, I; Schmidt, K H; Van De Vel, K; Van Duppen, P; Van Roosbroeck, J; Weissman, L

    2002-01-01

    The neutron-rich isotopes sup 7 sup 0 sup - sup 7 sup 6 Cu have been produced in 30-MeV proton-induced fission of sup 2 sup 3 sup 8 U using the Ion Guide Laser Ion Source (IGLIS) at LISOL. The production rates of the copper isotopes, and of the nickel and cobalt isotopes that were measured earlier, are compared to cross section calculations. Based on these new results an estimate for the cross section of sup 7 sup 8 Ni is given.

  7. Production of medical isotopes from a thorium target irradiated by light charged particles up to 70 MeV

    Science.gov (United States)

    Duchemin, C.; Guertin, A.; Haddad, F.; Michel, N.; Métivier, V.

    2015-02-01

    The irradiation of a thorium target by light charged particles (protons and deuterons) leads to the production of several isotopes of medical interest. Direct nuclear reaction allows the production of Protactinium-230 which decays to Uranium-230 the mother nucleus of Thorium-226, a promising isotope for alpha radionuclide therapy. The fission of Thorium-232 produces fragments of interest like Molybdenum-99, Iodine-131 and Cadmium-115g. We focus our study on the production of these isotopes, performing new cross section measurements and calculating production yields. Our new sets of data are compared with the literature and the last version of the TALYS code.

  8. Production of medical isotopes from a thorium target irradiated by light charged particles up to 70 MeV.

    Science.gov (United States)

    Duchemin, C; Guertin, A; Haddad, F; Michel, N; Métivier, V

    2015-02-07

    The irradiation of a thorium target by light charged particles (protons and deuterons) leads to the production of several isotopes of medical interest. Direct nuclear reaction allows the production of Protactinium-230 which decays to Uranium-230 the mother nucleus of Thorium-226, a promising isotope for alpha radionuclide therapy. The fission of Thorium-232 produces fragments of interest like Molybdenum-99, Iodine-131 and Cadmium-115g. We focus our study on the production of these isotopes, performing new cross section measurements and calculating production yields. Our new sets of data are compared with the literature and the last version of the TALYS code.

  9. Production of actinium, thorium and radium isotopes from natural thorium irradiated with protons up to 141 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Ermolaev, S.V.; Zhuikov, B.L.; Kokhanyuk, V.M.; Matushko, V.L. [Russian Academy of Sciences, Moscow (Russian Federation). Inst. of Nuclear Research; Kalmykov, S.N. [Lomonosov Moscow State Univ., Moscow (Russian Federation). Chemistry Dept.; Aliev, R.A. [Lomonosov Moscow State Univ., Moscow (Russian Federation). Skobeltsyn Inst. of Nuclear Physics; Tananaev, I.G.; Myasoedov, B.F. [Russian Academy of Sciences, Moscow (Russian Federation). A.N. Frumkin Inst. of Physical Chemistry and Electrochemistry

    2012-07-01

    Cross sections of {sup 225}Ac, {sup 227}Ac, {sup 227}Th and {sup 228}Th in thorium-232 targets irradiated with protons in the energy range 21-141 MeV have been measured. Based on these data, production yields of {sup 225}Ac and {sup 223}Ra in thick thorium targets have been calculated. It is possible to produce in proton energy range 60-140 MeV about 96 GBq (2.6 Ci) {sup 225}Ac per 10-d irradiation with 100 {mu}A proton beam current and 10-d decay, and much higher amount of {sup 223}Ra. The impurities of {sup 227}Ac and {sup 224}Ra are important and need to be assessed for further medical applications. (orig.)

  10. Production of isotopes and isomers with irradiation of Z = 47–50 targets by 23-MeV bremsstrahlung

    Energy Technology Data Exchange (ETDEWEB)

    Karamian, S. A., E-mail: karamian@nrmail.jinr.ru [Joint Institute for Nuclear Research (Russian Federation); Carroll, J. J. [US Army Research Laboratory (United States); Aksenov, N. V.; Albin, Yu. A.; Belov, A. G.; Bozhikov, G. A.; Dmitriev, S. N.; Starodub, G. Ya. [Joint Institute for Nuclear Research (Russian Federation)

    2015-09-15

    The irradiations of Ag to Sn targets by bremsstrahlung generated with 23-MeV electron beams are performed at the MT-25 microtron. Gamma spectra of the induced activities have been measured and the yields of all detected radionuclides and isomers are carefully measured and analyzed. A regular dependence of yields versus changed reaction threshold is confirmed. Many isomers are detected and the suppression of the production probability is observed with growing product spin. Special peculiarities for the isomer-to-ground state ratios were deduced for the {sup 106m}Ag, {sup 108m}Ag, {sup 113m}In, {sup 115m}In, and {sup 123m}Sn isomers. The production of such nuclides as {sup 108m}Ag, {sup 115m}In, {sup 117g}In, and {sup 113m}Cd is of interest for applications, especially when economic methods are available.

  11. Stable isotopes. Applications and production; Les isotopes stables. Applications - production

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, S.; Louvet, P.; Soulie, E. [eds.

    1994-12-31

    This conference presents 46 communications concerning stable isotope production, utilization and application, grouped in 6 sessions and posters. The various themes are: biological applications (pharmacology, medical diagnosis, metabolism and protein studies, toxicity and response studies, labelled compounds), analysis procedures (NMR analysis for macromolecules, tracer studies), nuclear applications (utilization of stable isotopes in nuclear reactors), biological, physical and chemical applications (mass transfer, mobility, crystallography, isotopic exchange), stable isotope production (ion chromatography, ion cyclotron resonance, cryogenic distillation).

  12. Independent isotopic yields in 25 MeV and 50 MeV proton-induced fission of {sup nat}U

    Energy Technology Data Exchange (ETDEWEB)

    Penttilae, H.; Gorelov, D.; Elomaa, V.V.; Eronen, T.; Hager, U.; Hakala, J.; Jokinen, A.; Kankainen, A.; Karvonen, P.; Moore, I.D.; Parkkonen, J.; Pohjalainen, I.; Rahaman, S.; Rinta-Antila, S.; Rissanen, J.; Saastamoinen, A.; Simutkin, V.; Sonoda, T.; Weber, C.; Voss, A.; Aeystoe, J. [Department of Physics, University of Jyvaskylae (Finland); Peraejaervi, K. [STUK - Radiation and Nuclear Safety Authority, Helsinki (Finland); Rubchenya, V.A. [Department of Physics, University of Jyvaskylae (Finland); V.G. Khlopin Radium Institute, St. Petersburg (Russian Federation)

    2016-04-15

    Independent isotopic yields for elements from Zn to La in the 25 MeV proton-induced fission of {sup nat}U were determined with the JYFLTRAP facility. In addition, isotopic yields for Zn, Ga, Rb, Sr, Zr, Pd and Xe in the 50 MeV proton-induced fission of {sup nat}U were measured. The deduced isotopic yield distributions are compared with a Rubchenya model, the GEF model with universal parameters and the semi-empirical Wahl model. Of these, the Rubchenya model gives the best overall agreement with the obtained data. Combining the isotopic yield data with mass yield data to obtain the absolute independent yields was attempted. The result depends on the mass yield distribution. (orig.)

  13. Isotope Production Facility (IPF)

    Data.gov (United States)

    Federal Laboratory Consortium — The Los Alamos National Laboratory has produced radioactive isotopes for medicine and research since the mid 1970s, when targets were first irradiated using the 800...

  14. Linacs for Medical Isotope Production

    Directory of Open Access Journals (Sweden)

    A. Pramudita

    2011-04-01

    Full Text Available This paper reviews efforts on using high energy (25-30 MeV and high power (10-20 kW electron linacs and lower energy (7 MeV proton linacs for medical radioisotope production. Using high energy x-rays from the electron linacs, PET (Positron Emission Tomography radioisotopes are produced through photonuclear reactions such as 19F(γ,n18F, which also allow production of other PET radionuclides 11C, 13N, and 15O. Other mostly used medical radionuclides 99mTc can also be obtained by using the electron linacs, through photofission or photonuclear reactions. Proton linacs for PET have also been recently developed and the product has been available in the market since 2005. The linacs have been tested for 18F production. As a proton accelerator, the target systems and nuclear reactions are similar to the ones used in PET cyclotrons

  15. Production of Medical Isotopes with Electron Linacs

    Energy Technology Data Exchange (ETDEWEB)

    Rotsch, D A; Alford, K.; Bailey, J. L.; Bowers, D. L.; Brossard, T.; Brown, M. A.; Chemerisov, S. D.; Ehst, D.; Greene, J.; Gromov, R. G.; Grudzinski, J.J.; Hafenrichter, L.; Hebden, A. S.; Henning, W.; Heltemes, T. A.; Jerden, J.; Jonah, C. D.; Kalensky, M.; Krebs, J. F.; Makarashvili, V.; Micklich, B.; Nolen, J.; Quigley, K. J.; Schneider, J. F.; Smith, N. A.; Stepinski, D. C.; Sun, Z.; Tkac, P.; Vandegrift, G. F.; Virgo, M J; Wesolowski, K. A.; Youker, A. J.

    2017-06-01

    Radioisotopes play important roles in numerous areas ranging from medical treatments to national security and basic research. Radionuclide production technology for medical applications has been pursued since the early 1900s both commercially and in nuclear science centers. Many medical isotopes are now in routine production and are used in day-to-day medical procedures. Despite these advancements, research is accelerating around the world to improve the existing production methodologies as well as to develop novel radionuclides for new medical appli-cations. Electron linear accelerators (linacs) represent a unique method for the production of radioisotopes. Even though the basic technology has been around for decades, only recently have electron linacs capable of producing photons with sufficient energy and flux for radioisotope production become available. Housed in Argonne Nation-al Laboratory’s Low Energy Accelerator Facility (LEAF) is a newly upgraded 55 MeV/25-kW electron linear ac-celerator, capable of producing a wide range of radioiso-topes. This talk will focus on the work being performed for the production of the medical isotopes 99Mo (99Mo/99mTc generator), 67Cu, and 47Sc.

  16. Measurement of isotopic cross sections of spallation residues in 800 A MeV {sup 197}Au + p collisions

    Energy Technology Data Exchange (ETDEWEB)

    Rejmund, F.; Mustapha, B.; Bernas, M.; Stephan, C.; Taieb, J.; Tassan-Got, L. [Institut de Physique Nucleaire, (IN2P3/CNRS) 91 - Orsay (France); Armbruster, P.; Benlliure, J.; Enqvist, T.; Schmidt, K.H.; Taieb, J. [GSI, Planckstrasse, Darmstadt (Germany); Benlliure, J. [Universidad de Santiago de Compostela (Spain); Boudard, A.; Legrain, R.; Leray, S.; Volant, C. [CEA/Saclay, Dept. d' Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l' Instrumentation Associee (DAPNIA), 91 - Gif-sur-Yvette (France); Dufour, J.P. [CENBG, IN2P3, 33 - Gradignan (France)

    2000-07-01

    The spallation of {sup 197}Au by 800 MeV protons was investigated in inverse kinematics at GSI, Darmstadt, by use of a {sup 197}Au beam bombarding a liquid-hydrogen target. The fragment separator (FRS) was used to select and identify the reaction products prior to {beta} decay. The individual production cross sections and the kinematical properties of 396 isotopes for all elements between mercury (Z=80) and neodymium (Z=60) have been measured. A comparison with Monte Carlo calculations based on different two-step models of the spallation reaction is given. The shape of the isotopic distributions close to the projectile is found to differ strongly from that resulting from aluminium-induced fragmentation of {sup 197}Au. The mean kinetic energies of the fragments are deduced from the experimental data. The importance of the new data to improve our understanding of the spallation mechanism and the relevance for the design of accelerator-driven sub-critical reactors is discussed. (authors)

  17. Production of α-particle emitting 211At using 45 MeV α-beam

    Science.gov (United States)

    Kim, Gyehong; Chun, Kwonsoo; Park, Sung Ho; Kim, Byungil

    2014-06-01

    Among the α-particle emitting radionuclides, 211At is considered to be a promising radionuclide for targeted cancer therapy due to its decay properties. The range of alpha particles produced by the decay of 211At are less than 70 µm in water with a linear energy transfer between 100 and 130 keV µm-1, which are about the maximum relative biological effectiveness for heavy ions. It is important to note that at the present time, only a few of cyclotrons routinely produce 211At. The direct production method is based on the nuclear reactions 209Bi(α,2n)211At. Production of the radionuclide 211At was carried out using the MC-50 cyclotron at the Korea Institute of Radiological and Medical Sciences (KIRAMS). To ensure high beam current, the α-beam was extracted with an initial energy of 45 MeV, which was degraded to obtain the appropriate α-beam energy. The calculations of beam energy degradation were performed utilizing the MCNPX. Alumina-baked targets were prepared by heating the bismuth metal powder onto a circular cavity in a furnace. When using an Eα, av of 29.17 MeV, the very small contribution of 210At confirms the right choice of the irradiation energy to obtain a pure production of 211At isotope.

  18. Deuteron-induced reactions on Ni isotopes up to 60 MeV

    Science.gov (United States)

    Avrigeanu, M.; Šimečková, E.; Fischer, U.; Mrázek, J.; Novak, J.; Štefánik, M.; Costache, C.; Avrigeanu, V.

    2016-07-01

    Background: The high complexity of the deuteron-nucleus interaction from the deuteron weak binding energy of 2.224 MeV is also related to a variety of reactions induced by the deuteron-breakup (BU) nucleons. Thus, specific noncompound processes as BU and direct reactions (DR) make the deuteron-induced reactions so different from reactions with other incident particles. The scarce consideration of only pre-equilibrium emission (PE) and compound-nucleus (CN) mechanisms led to significant discrepancies with experimental results so that recommended reaction cross sections of high-priority elements as, e.g., Ni have mainly been obtained by fit of the data. Purpose: The unitary and consistent BU and DR account in deuteron-induced reactions on natural nickel may take advantage of an extended database for this element, including new accurate measurements of particular reaction cross sections. Method: The activation cross sections of 64,61,60Cu, Ni,5765, and 55,56,57,58,59m,60Co nuclei for deuterons incident on natural Ni at energies up to 20 MeV, were measured by the stacked-foil technique and high-resolution gamma spectrometry using U-120M cyclotron of CANAM, NPI CAS. Then, within an extended analysis of deuteron interactions with Ni isotopes up to 60 MeV, all processes from elastic scattering until the evaporation from fully equilibrated compound system have been taken into account while an increased attention is paid especially to the BU and DR mechanisms. Results: The deuteron activation cross-section analysis, completed by consideration of the PE and CN contributions corrected for decrease of the total-reaction cross section from the leakage of the initial deuteron flux towards BU and DR processes, is proved satisfactory for the first time to all available data. Conclusions: The overall agreement of the measured data and model calculations validates the description of nuclear mechanisms taken into account for deuteron-induced reactions on Ni, particularly the BU and

  19. Neutron cross section evaluations of europium isotopes in 1 keV - 30 MeV energy range. Format - validation - comparison; Evaluation de sections efficaces pour des neutrons incidents sur des isotopes d'europium aux energies 1 keV - 30 MeV. Format - validation - comparaison

    Energy Technology Data Exchange (ETDEWEB)

    Dossantos-Uzarralde, P.; Le Luel, C.; Bauge, E. [CEA Bruyeres le Chatel, 91 (France). Dept. de Physique Theorique et Appliquee

    2004-07-01

    This paper presents neutron cross section evaluations of Europium isotopes. The cross sections are evaluated in 1 keV - 30 MeV energy range for the isotopes {sup 146}Eu, {sup 147}Eu, {sup 148}Eu, {sup 149}Eu, {sup 150}Eu, {sup 151}Eu, {sup 152}Eu, {sup 153}Eu, {sup 154}Eu in their ground state. This evaluation includes cross section productions of the long life isomeric states. Special attention is put on the options used for the description of the files written in ENDF-6 format. The final issue is a proposal of a new breed of ENDF-6 formatted neutron activation file. (authors)

  20. Production of platinum radioisotopes at Brookhaven Linac Isotope Producer (BLIP

    Directory of Open Access Journals (Sweden)

    Smith Suzanne V.

    2017-01-01

    Full Text Available The accelerator production of platinum isotopes was investigated at the Brookhaven Linac Isotope Producer (BLIP. In this study high purity natural platinum foils were irradiated at 53.2, 65.7, 105.2, 151.9, 162.9 and 173.3.MeV. The irradiated foils were digested in aqua regia and then converted to their hydrochloride salt with concentrated hydrochloric acid before analyzing by gamma spectrometry periodically for at least 10 days post end of bombardment. A wide range of platinum (Pt, gold (Au and iridium (Ir isotopes were identified. Effective cross sections at BLIP for Pt-188, Pt-189, Pt-191 and Pt-195m were compared to literature and theoretical cross sections determined using Empire-3.2. The majority of the effective cross sections (<70 MeV confirm those reported in the literature. While the absolute values of the theoretical cross sections were up to a factor of 3 lower, Empire 3.2 modeled thresholds and maxima correlated well with experimental values. Preliminary evaluation into a rapid separation of Pt isotopes from high levels of Ir and Au isotopes proved to be a promising approach for large scale production. In conclusion, this study demonstrated that with the use of isotopically enriched target material accelerator production of selected platinum isotopes is feasible over a wide proton energy range.

  1. Study on strontium isotope abundance-ratio measurements by using a 13-MeV proton beam

    Science.gov (United States)

    Jeong, Cheol-Ki; Jang, Han; Lee, Goung-Jin

    2016-09-01

    The Rb-Sr dating method is used in dating Paleozoic and Precambrian rocks. This method measures the 87Rb and the 87Sr concentrations by using thermal ionization mass spectrometry (TIMS) [J. Hefne et al., Inter. J. Phys. Sci. 3(1), 28 (2008)]. In addition, it calculates the initial 87Sr/86Sr ratio to increase the reliability of Rb-Sr dating. In this study, the 87Sr/86Sr ratio was measured by using a 13-MeV proton accelerator. Proton kinetic energies are in the range of tens of megaelectronvolts, and protons have large absorption cross-sections for ( p, n) reactions with most substances. After absorbing a proton with such a high kinetic energy, an element is converted into a nuclide with its atomic number increased by one via nuclear transmutation. These nuclides usually have short half-lives and return to the original state through radioactive decay. When a strontium sample is irradiated with protons, nuclear transmutation occurs; thus, the strontium isotope present in the sample changes to a yttrium isotope, which is an activated radioisotope. Based on this, the 87Sr/86Sr ratio was calculated by analyzing the gamma-rays emitted by each yttrium isotope. The KIRAMS-13 cyclotron at the Cyclotron Center of Chosun University, where 13-MeV protons can be extracted, was utilized in our experiment. The 87Sr/86Sr isotope ratio was computed for samples irradiated with these protons, and the result was similar to the isotope ratio for the Standard Reference Material, i.e., 98.2 ± 3.4%. As part of the analysis, proton activation analyses were performed using 13-MeV protons, and the experimental results of this research suggest a possible approach for measuring the strontium-isotope abundance ratio of samples.

  2. Yields of neutron-rich isotopes around Z = 28 produced in 30 MeV proton-induced fission of 238U

    Science.gov (United States)

    Kruglov, K.; Andreyev, A.; Bruyneel, B.; Dean, S.; Franchoo, S.; Górska, M.; Helariutta, K.; Huyse, M.; Kudryavtsev, Yu.; Mueller, W. F.; Prasad, N. V. S. V.; Raabe, R.; Schmidt, K.-H.; Van Duppen, P.; Van Roosbroeck, J.; Van de Vel, K.; Weissman, L.

    Heavy 65-70Co, 68-74Ni, 70-76Cu and 74-81Ga isotopes were produced at the LISOL facility by means of 30 MeV proton-induced fission of 238U. Production rates were deduced and compared to two types of cross-section calculations: the empirical model (V. Rubchenya, private communication) and the PROFI code. Comparison with experimental data favors the latter model. Yields using different beam-target combinations and different energies are calculated and discussed.

  3. Thick-target neutron, gamma-ray, and radionuclide production for protons below 12 MeV on nickel and carbon beam-stops

    Energy Technology Data Exchange (ETDEWEB)

    Chadwick, M.B.; Young, P.G.; Wilson, W.B.

    1998-03-01

    Nuclear model calculations using the GNASH code are described for protons below 12 MeV incident on nickel and carbon isotopes, for beam stop design in the Los Alamos Accelerator Production of Tritium Low Energy Demonstration Accelerator (LEDA) project. The GNASH calculations apply Hauser-Feshbach and preequilibrium reaction theories and can make use of pre-calculated direct reaction cross sections to low-lying residual nucleus states. From calculated thin target cross sections, thick target 6.7 MeV and 12 MeV proton-induced production of neutrons, gamma rays, and radionuclides are determined. Emission spectra of the secondary neutrons and gamma rays are also determined. The model calculations are validated through comparisons with experimental thin- and thick-target measurements. The results of this work are being utilized as source terms in MCNP analyses for LEDA.

  4. High-precision gamma-ray spectroscopy for enhancing production and application of medical isotopes

    Science.gov (United States)

    McCutchan, E. A.; Sonzogni, A. A.; Smith, S. V.; Muench, L.; Nino, M.; Greene, J. P.; Carpenter, M. P.; Zhu, S.; Chillery, T.; Chowdhury, P.; Harding, R.; Lister, C. J.

    2015-10-01

    Nuclear medicine is a field which requires precise decay data for use in planning radionuclide production and in imaging and therapeutic applications. To address deficiencies in decay data, sources of medical isotopes were produced and purified at the Brookhaven Linear Isotope Producer (BLIP) then shipped to Argonne National Laboratory where high-precision, gamma-ray measurements were performed using Gammasphere. New decay schemes for a number of PET isotopes and the impact on dose calculations will be presented. To investigate the production of next-generation theranostic or radiotherapeutic isotopes, cross section measurements with high energy protons have also been explored at BLIP. The 100-200 MeV proton energy regime is relatively unexplored for isotope production, thus offering high discovery potential but at the same time a challenging analysis due to the large number of open channels at these energies. Results of cross sections deduced from Compton-suppressed, coincidence gamma-ray spectroscopy performed at Lowell will be presented, focusing on the production of platinum isotopes by irradiating natural platinum foils with 100 to 200 MeV protons. DOE Isotope Program is acknowledged for funding ST5001030. Work supported by the US DOE under Grant DE-FG02-94ER40848 and Contracts DE-AC02-98CH10946 and DE-AC02-06CH11357.

  5. Beneficial uses and production of isotopes

    CERN Document Server

    2001-01-01

    Isotopes, radioactive and stable, are used worldwide in various applications related to medical diagnosis or care, industry and scientific research. More than fifty countries have isotope production or separation facilities operated for domestic supply, and sometimes for international markets. This publication provides up-to-date information on the current status of, and trends in, isotope uses and production. It also presents key issues, conclusions and recommendations, which will be of interest to policy makers in governmental bodies, scientists and industrial actors in the field.

  6. The production of stable isotopes in Spain

    Energy Technology Data Exchange (ETDEWEB)

    Urgel, M.; Iglesias, J.; Casas, J.; Saviron, J. M.; Quintanilla, M.

    1965-07-01

    The activities developed in the field of the production of stable isotopes by means of ion-exchange chromatography and thermal diffusion techniques are reported. The first method was used to study the separation of the nitrogen and boron isotopes, whereby the separation factor was determined by the break through method. Values ranging from 1,028 to 1,022 were obtained for the separation factor of nitrogen by using ammonium hydroxide solutions while the corresponding values as obtained for boron amounted to 1,035-1,027 using boric acid solutions. Using ammonium chloride or acetate and sodium borate, respectively, resulted in the obtention of values for the separation factor approaching unity. The isotopic separation has been carried out according to the method of development by displacement. The separation of the isotopes of the noble gases, oxygen, nitrogen and carbon has been accomplished resorting to the method of thermal diffusion. (Author) 16 refs.

  7. Accelerator Production of Isotopes for Medical Use

    Science.gov (United States)

    Lapi, Suzanne

    2014-03-01

    The increase in use of radioisotopes for medical imaging and therapy has led to the development of novel routes of isotope production. For example, the production and purification of longer-lived position emitting radiometals has been explored to allow for nuclear imaging agents based on peptides, antibodies and nanoparticles. These isotopes (64Cu, 89Zr, 86Y) are typically produced via irradiation of solid targets on smaller medical cyclotrons at dedicated facilities. Recently, isotope harvesting from heavy ion accelerator facilities has also been suggested. The Facility for Rare Isotope Beams (FRIB) will be a new national user facility for nuclear science to be completed in 2020. Radioisotopes could be produced by dedicated runs by primary users or may be collected synergistically from the water in cooling-loops for the primary beam dump that cycle the water at flow rates in excess of hundreds of gallons per minute. A liquid water target system for harvesting radioisotopes at the National Superconducting Cyclotron Laboratory (NSCL) was designed and constructed as the initial step in proof-of-principle experiments to harvest useful radioisotopes in this manner. This talk will provide an overview of isotope production using both dedicated machines and harvesting from larger accelerators typically used for nuclear physics. Funding from Department of Energy under DESC0007352 and DESC0006862.

  8. Production of radioactive isotopes from stable isotopes, for nuclear medicine; A partir d`isotopes stables, production d`isotopes radioactifs pour la medecine nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Bourdoiseau, M. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Office des Rayonnements Ionisants

    1994-12-31

    Around 15 radioactive isotopes only are used for nuclear medicine diagnosis (kinetics or preferential fixation in the body); characteristics of these {gamma} and {beta}-minus emitters are presented: period, energy, production mode (isotopic filiation, fission product separation, cyclotron, reactor); details are given on applications, production mode, properties and consumption of various isotopes: Technetium 99m, Thallium 201, Iodine 123, Indium 111, Gallium 67, Rhenium 186, Erbium 169, Yttrium 90, Iron 59, Chromium 51, Krypton 81m. 1 tab.

  9. MeV He3/He4 isotope abundances in solar energetic particle events: SOHO/COSTEP observations

    Science.gov (United States)

    Bothmer, V.:; Sierks, H.; Böhm, E.; Kunow, H.

    2001-08-01

    We present first results based on a systematic survey of 4-41 MeV/N 3He/4He isotope abundances with ratios >0.01 detected by the COmprehensive SupraThermal and Energetic Particle analyzer (COSTEP) onboard the SOHO (SOlar and Heliospheric Observatory) spacecraft. More than about 25% of the identified events showed 3He/4He ratios in the range 0.1-1. For events with sufficiently high detector count rates the atomic mass plots can be resolved up to a time resolution of about 1 hour. These events are most suitable for comparisons with in situ solar wind plasma and magnetic field measurements and SOHO's optical white-light and extreme ultraviolet (EUV) observations of the Sun. The correlations show an association with passages of shock associated coronal mass ejections (CMEs) in the solar wind that inhibit high He/H plasma overabundances. It is likely that the CMEs have been released in strong magnetic reconfiguration processes at the solar source sites. Here we present a brief overview of such an event detected on October 30, 2000. 1. Introduction The SOHO/COSTEP instrument measures solar energetic particles (SEPs) at MeV energies in the interplanetary medium. The solid state detectors are capable to detect 3 He/4 He-enrichments at these energies (Müller-Mellin et al., 1995). Usually, the 3 He/4 He-ratio in the solar wind is at the order of 10-4 , but occasionally ratios up to about values of ~1 or even above have been observed in SEP events (e.g., Mason et al., 1999). The origin of these isotope abundances has commonly been attributed to impulsive solar flares and wave-particle interaction mechanisms (Temerin and Roth, 1992). However, fully satisfying physical explanations are still lacking. Here we present first results of a systematic survey of the He-measurements taken by COSTEP since launch in 1995 until the end of the year 2000. 2. Data For this study we have analyzed SOHO/COSTEP measurements of 4.3-40.9 MeV/N helium particles as well as COSTEP data covering

  10. Production and identification of new neutron-deficient isotope 235Am in region of transuranium

    Institute of Scientific and Technical Information of China (English)

    甘再国; 郭俊盛; 刘洪业; 石立军; 杨维凡; 牟万统; 郭天瑞; 方克明; 沈水法; 袁双贵; 张学谦; 秦芝; 马瑞昌; 钟纪泉; 罗亦孝; 王书鸿; 孔登明; 乔际民

    1997-01-01

    A new transuranium neutron-deficient isotope 235Am was produced by 35 MeV proton to bombard the rare radioactive 238Pu target The products were transported and collected by the He-jet system. The Am isotopes were separated and purified by radiochemtstry method and the γ-ray, X-ray and γ-X(γ) coincidence of the samples was measured The synthesis of 235 Am was definitely identified Its measured half-life is (15±5) mom.

  11. Energy Dependence of Neutron-Induced Fission Product Yields of 235U, 238U and 239Pu Between 0.5 and 14.8 MeV

    Science.gov (United States)

    Gooden, Matthew; Tornow, Werner; Tonchev, Anton; Vieira, Dave; Wilhelmy, Jerry; Arnold, Charles; Fowler, Malcolm; Stoyer, Mark

    2014-09-01

    Under a joint collaboration between TUNL-LANL-LLNL, a set of absolute fission product yield measurements have been performed. The energy dependence of a number of cumulative fission products between 0.5 and 14.8 MeV have been measured using quasi-monoenergetic neutron beams for three actinide targets, 235U, 238U and 239Pu, between 0.5 and 14.8 MeV. The FPYs were measured by a combination of activation utilizing specially designed dual-fission chambers and γ-ray counting. The dual-fission chambers are back-to-back ionization chambers encasing a target with thin deposits of the same target isotope in each chamber. This method allows for the direct measurement of the fission rate in the activation target with no reference to the fission cross-section, reducing uncertainties. γ-ray counting was performed on well-shield HPGe detectors over a period of 2 months per activation to properly identify fission products. Reported are absolute cumulative fission product yields for incident neutron energies of 0.5, 1.37, 2.4, 4.6 and 14.8 MeV.

  12. Calculation of nucleon production cross sections for 200 MeV deuterons

    Energy Technology Data Exchange (ETDEWEB)

    Ridikas, D.; Mittig, W.

    1997-12-31

    The differential neutron and proton production cross sections have been investigated for 200 MeV incident deuterons on thin and thick {sup 9}Be, {sup 56}Fe and {sup 238}U targets using the LAHET code system. The examples of the deuteron beam on different target materials are analysed to determine the differences of converting the energy of the beam into the nucleons produced. Both double differential, energy and angle integrated nuclear production cross sections are presented together with the average nucleon multiplicities per incident deuteron. (K.A.). 31 refs.

  13. Neutron- and proton-induced nuclear data evaluation of thorium, uranium and curium isotopes for energies up to 250 MeV

    CERN Document Server

    Young, Ouk Lee; Jonghwa, Chang; Konobeyev, A Yu

    2004-01-01

    The evaluation of neutron- and proton nuclear data for thorium-232, U-233,234,236, and Cm-243,244,245,246 isotopes have been performed at energies up to 250 MeV. Neutron data was evaluated at energies from 20 MeV to 250 MeV, and combined with the JENDL-3.3 data at 20 MeV while proton data was obtained for energies from 1 to 250 MeV. Nuclear model parameters are largely based on the IAEA-RIPL recommendation, and adjusted to better reproduce the available measurements. The coupled channel optical model was applied to calculate the total, reaction, elastic, and direct inelastic cross sections, and to obtain the transmission coefficients. Decay of excited nuclei was described with the Hauser-Feshbach and exciton models using the GNASH code to simultaneously handle neutron, proton, deuteron, triton, helium-3, alpha , gamma emissions and fissions. Special attention was paid on the fission cross sections for energies where experimental data are scant, using appropriate systematics and fittings. Particles and gamma e...

  14. Production of 99Mo Using 33 MeV Electron and 100Mo Target

    Institute of Scientific and Technical Information of China (English)

    LIU; Bao-jie; LI; Jin-hai; ZENG; Zi-qiang

    2015-01-01

    The(γ,n)reaction on a 100Mo target is considered to produce the radioactive isotope 100Mo.The advantages of this reaction are the relatively high reaction cross section and the elimination of the expensive fission products chemistry steam associated with irradiation of uranium.The rela-

  15. Determining isotopic distributions of fission products with a penning trap

    Energy Technology Data Exchange (ETDEWEB)

    Penttilae, H.; Karvonen, P.; Eronen, T.; Elomaa, V.V.; Hager, U.; Hakala, J.; Jokinen, A.; Kankainen, A.; Moore, I.D.; Peraejaervi, K.; Rahaman, S.; Rinta-Antila, S.; Saastamoinen, A.; Sonoda, T.; Aeystoe, J. [University of Jyvaeskylae, Department of Physics, Jyvaeskylae (Finland); Rubchenya, V. [University of Jyvaeskylae, Department of Physics, Jyvaeskylae (Finland); V.G. Khlopin Radium Institute, St. Petersburg (Russian Federation)

    2010-04-15

    A novel method to determine independent yields in particle-induced fission employing the ion guide technique and ion counting after a Penning trap has been developed. The method takes advantage of the fact that a Penning trap can be used as a precision mass filter, which allows an unambiguous identification of the fission fragments. The method was tested with 25MeV and 50MeV proton-induced fission of {sup 238}U. The data is internally reproducible with an accuracy of a few per cent. A satisfactory agreement was obtained with older ion guide yield measurements in 25MeV proton-induced fission. The results for Rb and Cs yields in 50MeV proton-induced fission agree with previous measurements performed at an isotope separator equipped with a chemically selective ion source. (orig.)

  16. Stable isotope production with laser techniques; Production d`isotopes stables a l`aide des techniques laser

    Energy Technology Data Exchange (ETDEWEB)

    Petit, A. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. des Procedes d`Enrichissement

    1994-12-31

    Laser properties may be used for stable isotope production either by selective photoionization of an atom particular isotope, either by selective photodissociation of a molecule. Principles of both processes are reviewed and examples of calcium 43 isotope separation through photoionization and of carbon and oxygen isotope separation by photodissociation are presented. 4 figs., 1 tab., 11 refs.

  17. MeV Neutron Production from Thermal Neutron Capture in {6}^Li Simulated with Geant4

    CERN Document Server

    Santoro, Valentina; Bentley, Phillip M

    2015-01-01

    Various Li compounds are commonly used at neutron facilities as neutron absorbers. These compounds provide one of the highest ratios of neutron attenuation to $\\gamma$-ray production. Unfortunately, the usage of these compounds can also give rise to fast neutron emission with energies up to almost 16 MeV. Historically, some details in this fast neutron production mechanism can be absent from some modeling packages under some optimization scenarios. In this work, we tested Geant4 to assess the performance of this simulation toolkit for the fast neutron generation mechanism. We compare the results of simulations performed with Geant4 to available measurements. The outcome of our study shows that results of the Geant4 simulations are in good agreement with the available measurements for $^6$Li fast neutron production, and suitable for neutron instrument background evaluation at spallation neutron sources.

  18. MeV Neutron Production from Thermal Neutron Capture in 6Li Simulated With Geant4

    Science.gov (United States)

    Santoro, Valentina; DiJulio, Douglas D.; Bentley, Phillip M.

    2016-09-01

    Various Li compounds are commonly used at neutron facilities as neutron absorbers. These compounds provide one of the highest ratios of neutron attenuation to y- ray production. Unfortunately, the usage of these compounds can also give rise to fast neutron emission with energies up to almost 16 MeV. Historically, some details in this fast neutron production mechanism can be absent from some modeling packages under some optimization scenarios. In this work, we tested Geant4 to assess the performance of this simulation toolkit for the fast neutron generation mechanism. We compare the results of simulations performed with Geant4 to available measurements. The outcome of our study shows that results of the Geant4 simulations are in good agreement with the available measurements for 6 Li fast neutron production, and suitable for neutron instrument background evaluation at spallation neutron sources.

  19. Tritium production in a sphere of /sup 6/LiD irradiated by 14-MeV neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Hemmendinger, A.; Ragan, C.E.; Shunk, E.R.; Ellis, A.N.; Anaya, J.M.; Wallace, J.M.

    1978-10-01

    The specific production of tritium in samples of /sup 6/LiH and /sup 7/LiH embedded in a 600-mm-diam sphere of /sup 6/LiD irradiated by a central source of 14-MeV neutrons was determined by measuring the activity of the hydrogen evolved from the samples of each isotope at each of five different radii in the /sup 6/LiD assembly. The entire process of decomposing the LiH, transferring the evolved gas into counters, and determining the decay rate was standardized by processing LiH samples irradiated by thermal neutrons for which the /sup 6/Li(n,..cap alpha..) cross section is well known. The specific production of tritium in /sup 6/LiH and /sup 7/LiH (embedded samples) and the activation of radiochemical detector foils of /sup 45/Sc, /sup 89/Y, /sup 90/Zr, /sup 169/Tm, /sup 191/Ir /sub 373/, /sup 193/Ir /sub 627/, /sup 197/Au, /sup 235/U, and /sup 238/U placed at various positions in the /sup 6/LiD sphere were calculated and compared with the experimental data. One- and three-dimensional Monte Carlo and S/sub n/ neutron-transport calculations were performed. The most reliable (three-dimensional Monte Carlo) calculation is in reasonable agreement with both the tritium-production and the radiochemical-activation data. The existing discrepancies between calculation and experiment appear largely attributable to uncertainties in some tritium-production and radiochemical-activation cross sections. 15 references.

  20. Production Situation and Technology Prospect of Medical Isotopes

    Directory of Open Access Journals (Sweden)

    GAO Feng;LIN Li;LIU Yu-hao;MA Xing-jun

    2016-10-01

    Full Text Available The isotope production technology was overviewed, including traditional and newest technology. The current situation of medical isotope production was introduced. The problems faced by isotope supply and demand were analyzed. The future development trend of medical isotopes and technology prospect were put forward. As the most populous country, nuclear medicine develops rapidly, however, domestic isotope mainly relies on imports. The highly productive and relatively safe MIPR is expected to be an effective way to breakthrough the bottleneck of the development of nuclear medicine. Traditional isotope production technologies with reactor can be improved. It's urgent to research and promote new isotope production technologies with reactor. Those technologies which do not depend on reactor will have a bright market prospects.

  1. Activation of air and concrete in medical isotope production facilities

    Science.gov (United States)

    Dodd, Adam C.; Shackelton, R. J.; Carr, D. A.; Ismail, A.

    2017-05-01

    Medical isotope facilities operating in the 10 to 25 MeV proton energy range have long been used to generate radioisotopes for medical diagnostic imaging. In the last few years the beam currents available in commercially available cyclotrons have increased dramatically, and so the activation of the materials within cyclotron vaults may now pose more serious radiological hazards. This will impact the regulatory oversight of cyclotron operations, cyclotron servicing and future decommissioning activities. Air activation could pose a hazard to cyclotron staff. With the increased cyclotron beam currents it was necessary to examine the issue more carefully. Therefore the ways in which radioactivity may be induced in air by neutron reactions and neutron captures were considered and it was found that the dominant mechanism is neutron capture on Ar-40. A study of the activation of the air by neutron capture on Ar-40 within a cyclotron vault was performed using the MCNP Monte Carlo code. The neutron source energy spectrum used was from the production of the widely used F-18 PET isotope. The results showed that the activation of the air within a cyclotron vault does not pose a significant radiological hazard at the beam intensities currently in use and shows how ventilation affects the results. A second MCNP study on the activation of ordinary concrete in cyclotron vaults by neutron capture was made with a view to determining the optimum thickness of borated polyethylene to reduce neutron activation on both the inner surfaces of the vault and around production targets. This is of importance in decommissioning cyclotrons and therefore in the design of new cyclotron vaults. The distribution of activation on the walls as a function of the source position was also studied. Results are presented for both borated and regular polyethylene, and F-18 and Tc-99 neutron spectra.

  2. Isotope products manufacture in Russia and its prospects

    Energy Technology Data Exchange (ETDEWEB)

    Malyshev, S.V.; Okhotina, I.A.; Kalelin, E.A.; Krasnov, N.N.; Kuzin, V.V.; Malykh, J.A.; Makarovsky, S.B. [Tenex, Techsnabexport Co Ltd, Moscow (Russian Federation)

    1997-10-01

    At the present stage of the world economy development, stable and radioactive isotopes,preparations and products on their base are widely used in many fields of the national economy, medicine and scientific researches. The Russian Federation is one of the largest worldwide producers of a variety of nuclide products on the base of more than 350 isotopes, as follows: stable isotopes reactor, cyclotron, fission product radioactive isotopes, ion-radiation sources compounds, labelled with stable and radioactive isotopes, radionuclide short-lived isotope generators, radiopharmaceuticals, radionuclide light and heat sources; luminous paints on base of isotopes. The Russian Ministry for Atomic Energy coordinates activity for development and organization of manufacture and isotope products supply in Russia as well as for export. Within many years of isotope industry development, there have appeared some manufacturing centres in Russia, dealing with a variety of isotope products. The report presents the production potentialities of these centres and also an outlook on isotope production development in Russia in the next years

  3. Depicting the MeV realm with the Compton Pair-Production Telescope (ComPair)

    Science.gov (United States)

    Ferrara, Elizabeth C.; Buson, Sara; ComPair Mission Team

    2017-01-01

    The energy band from a few hundred keV to a few hundred MeV offers a unique window for studying both thermal and the non-thermal astrophysical processes. Important science can be gleaned from investigations of emission mechanisms and environments of the most extreme objects that populate this mostly unexplored energy range.The Compton-Pair Telescope (ComPair) is a next-generation mission concept building on the pioneering observations by COMPTEL, on the Compton Gamma-Ray Observatory, and the heritage of recent successful missions, such as Fermi-LAT, AGILE, AMS and PAMELA. With its capability of detecting both Compton-scattering events at lower energy and pair-production events at higher energy, ComPair can explore the energy regime from 0.2 keV to > 500 MeV with unprecedented sensitivity. We describe the concept of this wide-aperture instrument and discuss its power to address fundamental questions from a broad variety of astrophysical topics.

  4. Cross-section measurements for (n, 2n) reactions on stannum isotopes in the neutron energy range of 13.5 to 14.6 MeV

    Institute of Scientific and Technical Information of China (English)

    PU Zhong-Sheng; YAN Dong; MA Jun; DU Xiao-Fang; GUAN Qiu-Yun

    2008-01-01

    Cross-sections for (n, 2n) reactions have been measured on stannum isotopes at the neutron energies of 13.5 to 14.6 MeV using the activation technique. Data are reported for the following reactions:112Sn(n, 2n)111Sn, 118Sn(n, 2n)117Sn and 124Sn(n, 2n)123mSn. The neutron fluences were determined using the monitor reaction 93Nb(n, 2n)92mNb or 27Al(n, α)24Na. The results of present work were compared with data published previously.

  5. Elastic and inelastic scattering of 2 to 10 MeV protons by lithium isotopes; Diffusion elastique et inelastique des protons de 2 a 10 MeV par les isotopes du lithium

    Energy Technology Data Exchange (ETDEWEB)

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

    1969-07-01

    A description is given of the experimental set-up which has been devised for carrying out spectrometric and absolute cross-section measurements on the reactions induced by protons accelerated in a 12 MeV Van de Graaff Tandem. The particles are detected by silicon junctions; the weight of the targets (about ten {mu}g/cm{sup 2}) is determined by the quartz method. The experimental equipment has been controlled by a study of proton scattering by lithium-6, and has made it possible to evaluate the elastic and inelastic scattering (1. level excitation) by lithium 7 of 2 to 9 MeV protons. The most probable spin and parity values for the six levels of {sup 8}Be between 19 and 25 MeV excitation energy have been determined from a knowledge of the observed structure. (author) [French] Nous decrivons le dispositif experimental mis au point pour effectuer les mesures de spectrometrie et de section efficace absolue pour les reactions induites par des protons acceleres par un Van de Graaff Tandem 12 MeV. Les particules sont detectees par des jonctions au silicium, le poids des cibles (de l'ordre d'une dizaine de {mu}g/cm{sup 2}), mesure par la methode du quartz. L'ensemble de l'appareillage a ete controle par l'etude de la diffusion des protons par le lithium 6, et nous a permis de preciser les diffusions elastiques et inelastiques (excitation du 1er niveau) des protons de 2 a 9 MeV par le lithium 7. La structure observee a permis de determiner les spin et parite les plus probables de six niveaux du {sup 8}Be entre 19 et 25 MeV d'energie d'excitation. (auteur)

  6. Simulation study of neutron production in thick beryllium targets by 35 MeV and 50.5 MeV proton beams

    Science.gov (United States)

    Shin, Jae Won; Park, Tae-Sun

    2017-09-01

    A data-driven nuclear model dedicated to an accurate description of neutron productions in beryllium targets bombarded by proton beams is developed as a custom development that can be used as an add-on to GEANT4 code. The developed model, G4Data(Endf7.1), takes as inputs the total and differential cross section data of ENDF/B-VII.1 for not only the charge-exchange 9Be(p,n)9B reaction which produces discrete neutrons but also the nuclear reactions relevant for the production of continuum neutrons such as 9Be(p,pn)8Be and 9Be(p,n α) 5Li . In our benchmarking simulations for two experiments with 35 MeV and 50.5 MeV proton beams impinged on 1.16 and 1.05 cm thick beryllium targets, respectively, we find that the G4Data(Endf7.1) model can reproduce both the total amounts and the spectral shapes of the measured neutron yield data in a satisfactory manner, while all the considered hadronic models of GEANT4 cannot.

  7. Direct Technetium radiopharmaceuticals production using a 30MeV Cyclotron

    Directory of Open Access Journals (Sweden)

    M Kamali Dehgan

    2011-07-01

    Full Text Available Background and purpose of the study: Technetium-99m is the major radionuclide used in the world and mainly is provided by fission product. However extensive research has been conducted on the use of accelerators for production of 99mTc. This investigation reports the production of 99mTc radioisotope using cyclotrons followed by the preparation, quality control and biodistribution studies of four major Tc-radiopharmaceuticals. Methods: The high purity molybdenum natural target (130mg/cm2 was irradiated in a Cyclone 30 accelerator using 160 µA of 25 MeV proton beam energy for 1000 µA-h. After dissolution, the technetium radionuclides were extracted using methyl ethyl ketone (MEK followed by preparation of Tc-MIBI, Tc-DTPA, Tc-DMSA and Tc-phytate as radiopharmaceutical samples. Results: The results of quality controls and animal biodistribution studies showed successful production of Tc radionuclides (including 99mTc in the bombarded target and subsequent labelling of the kit with Tc. Conclusion: The developed high power Mo target if constructed using enriched 100Mo, could be a practical method for large-scale production of 99mTc and promising as an alternative to fission product 99Mo-99mTc generators for local applications near cyclotron facilities.

  8. Determination of Fission Product Yields of 235U, 238U and 239Pu for Neutron Energies from 0.5 to 14.8 MeV

    Science.gov (United States)

    Gooden, Matthew; Arnold, Charles; Becker, John; Bhatia, Chitra; Bhike, Megha; Fowler, Malcolm; Howell, Calvin; Kelley, John; Stoyer, Mark; Tonchev, Anton; Tornow, Werner; Vieira, Dave; Wilhelmy, Jerry

    2014-03-01

    A joint TUNL-LANL-LLNL collaboration has been formed to study the issue of possible energy dependences for certain fission product isotopes. Work has been carried out at the TUNL 10 MV Tandem accelerator which produces nearly mono-energetic neutrons via either 2H(d,n)3He,3H(d,n)4He,or3H(p,n)3He reactions. Three dual fission ionization chambers dedicated to 235U, 238U and 239Pu thick target foils and thin monitor foils respectively, were exposed to the neutron beams. After irradiation, thick target foils were gamma counted over a period of 1-2 months and characteristic gamma rays from fission products were recorded using HPGe detectors at TUNL's low background counting area. Using the dual fission chambers, relative fission product yield were determined at a high precision of 2-3 % as well as absolute fission product yields at a lower precision of 5-6 %. Preliminary results will be presented for a number of fission product isotopes over the incident neutron energy range of 0.5 to 14.8 MeV.

  9. Large scale accelerator production of (225)Ac: Effective cross sections for 78-192MeV protons incident on (232)Th targets.

    Science.gov (United States)

    Griswold, J R; Medvedev, D G; Engle, J W; Copping, R; Fitzsimmons, J M; Radchenko, V; Cooley, J C; Fassbender, M E; Denton, D L; Murphy, K E; Owens, A C; Birnbaum, E R; John, K D; Nortier, F M; Stracener, D W; Heilbronn, L H; Mausner, L F; Mirzadeh, S

    2016-12-01

    Actinium-225 and (213)Bi have been used successfully in targeted alpha therapy (TAT) in preclinical and clinical research. This paper is a continuation of research activities aiming to expand the availability of (225)Ac. The high-energy proton spallation reaction on natural thorium metal targets has been utilized to produce millicurie quantities of (225)Ac. The results of sixteen irradiation experiments of thorium metal at beam energies between 78 and 192MeV are summarized in this work. Irradiations have been conducted at Brookhaven National Laboratory (BNL) and Los Alamos National Laboratory (LANL), while target dissolution and processing was carried out at Oak Ridge National Laboratory (ORNL). Excitation functions for actinium and thorium isotopes, as well as for some of the fission products, are presented. The cross sections for production of (225)Ac range from 3.6 to 16.7mb in the incident proton energy range of 78-192MeV. Based on these data, production of curie quantities of (225)Ac is possible by irradiating a 5.0gcm(-2 232)Th target for 10 days in either BNL or LANL proton irradiation facilities. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. High power laser production of short-lived isotopes for positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Ledingham, K W D [Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); McKenna, P [Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); McCanny, T [Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Shimizu, S [Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Yang, J M [Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Robson, L [Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Zweit, J [CR-UK/UMIST Radiochemical Targeting and Imaging, Paterson Institute for Cancer Research, Christie Hospital, Manchester M20 4BX (United Kingdom); Gillies, J M [CR-UK/UMIST Radiochemical Targeting and Imaging, Paterson Institute for Cancer Research, Christie Hospital, Manchester M20 4BX (United Kingdom); Bailey, J [CR-UK/UMIST Radiochemical Targeting and Imaging, Paterson Institute for Cancer Research, Christie Hospital, Manchester M20 4BX (United Kingdom); Chimon, G N [CR-UK/UMIST Radiochemical Targeting and Imaging, Paterson Institute for Cancer Research, Christie Hospital, Manchester M20 4BX (United Kingdom); Clarke, R J [Central Laser Facility, CCLRC Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX110QX (United Kingdom); Neely, D [Central Laser Facility, CCLRC Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX110QX (United Kingdom); Norreys, P A [Central Laser Facility, CCLRC Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX110QX (United Kingdom); Collier, J L [Central Laser Facility, CCLRC Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX110QX (United Kingdom); Singhal, R P [Department of Physics and Astronomy, University of Glasgow G12 8QQ (United Kingdom); Wei, M S [Blackett Laboratory, Imperial College of Science, Technology and Medicine, London SW7 2BZ (United Kingdom)] [and others

    2004-08-21

    Positron emission tomography (PET) is a powerful diagnostic/imaging technique requiring the production of the short-lived positron emitting isotopes {sup 11}C, {sup 13}N, {sup 15}O and {sup 18}F by proton irradiation of natural/enriched targets using cyclotrons. The development of PET has been hampered due to the size and shielding requirements of nuclear installations. Recent results show that when an intense laser beam interacts with solid targets, megaelectronvolt (MeV) protons capable of producing PET isotopes are generated. This report describes how to generate intense PET sources of {sup 11}C and {sup 18}F using a petawatt laser beam. The work describing the laser production of {sup 18}F through a (p,n) {sup 18}O reaction, and the subsequent synthesis of 2-[{sup 18}F] is reported for the first time. The potential for developing compact laser technology for this purpose is discussed.

  11. Development of lowenergy accelerator-based production of medical isotopes

    OpenAIRE

    Radcliffe, Naomi; Barlow, Roger; Cywinski, Robert; Beasley, P.

    2013-01-01

    Here we present methods for production of new and existing isotopes for SPECT (Single Photon Emission Computed Tomography) and PET (Positron Emission Tomography) imaging using accelerator-based systems. Such isotopes are already widely used in medical diagnostics and research, and there is constant development of new drugs and isotopes. However the main production method for 99mTc, is currently in research reactors and is at risk due to scheduled and unscheduled shut downs. Therefore, a low c...

  12. 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...

  13. Studies on Separation Process and Production Technology of Boron Isotope

    Directory of Open Access Journals (Sweden)

    LI Jian-ping

    2014-02-01

    Full Text Available The boron isotopes separation test was performed by chemical exchange reaction in the benzene ether -three boron fluoride system, which resulted to the boron isotopic enrichment of -10 in the liquid phase, the boron isotopic enrichment of -11 in the gas phase. After then, boron isotope separation trial production has been finished. In this process, the exchange column and complex tower normal operating parameters and the complex tower technology have been obtained, the problems of material distillation purification is solved, boron isotopes feasibility with PTFE packing enrichment is verified in an exchange column. Also, effect of operating pressure, flow and other parameters on boron -10 isotopic enrichment experiments and the effect and properties of the PTFE packing have been investigated in the existing system. All the results are very useful for the industrialization of the boron isotopes separation system.

  14. Design study of an ultra-compact superconducting cyclotron for isotope production

    Science.gov (United States)

    Smirnov, V.; Vorozhtsov, S.; Vincent, J.

    2014-11-01

    A 12.5 MeV, 25 μA, proton compact superconducting cyclotron for medical isotope production has been designed and is currently in fabrication. The machine is initially aimed at producing 13N ammonia for Positron Emission Tomography (PET) cardiology applications. With an ultra-compact size and cost-effective price point, this system will offer clinicians unprecedented access to the preferred radiopharmaceutical isotope for cardiac PET imaging. A systems approach that carefully balanced the subsystem requirements coupled to precise beam dynamics calculations was followed. The system is designed to irradiate a liquid target internal to the cyclotron and to minimize the need for radiation shielding. The main parameters of the cyclotron, its design, and principal steps of the development work are presented here.

  15. Fuel preparation for use in the production of medical isotopes

    Science.gov (United States)

    Policke, Timothy A.; Aase, Scott B.; Stagg, William R.

    2016-10-25

    The present invention relates generally to the field of medical isotope production by fission of uranium-235 and the fuel utilized therein (e.g., the production of suitable Low Enriched Uranium (LEU is uranium having 20 weight percent or less uranium-235) fuel for medical isotope production) and, in particular to a method for producing LEU fuel and a LEU fuel product that is suitable for use in the production of medical isotopes. In one embodiment, the LEU fuel of the present invention is designed to be utilized in an Aqueous Homogeneous Reactor (AHR) for the production of various medical isotopes including, but not limited to, molybdenum-99, cesium-137, iodine-131, strontium-89, xenon-133 and yttrium-90.

  16. η-meson production in proton-proton collisions at excess energies of 40 and 72 MeV

    Science.gov (United States)

    Petrén, H.; Bargholtz, Chr.; Bashkanov, M.; Bogoslavsky, D.; Calén, H.; Clement, H.; Demirörs, L.; Ekström, C.; Fransson, K.; Fäldt, G.; Gerén, L.; Höistad, B.; Ivanov, G.; Jacewicz, M.; Jiganov, E.; Johansson, T.; Keleta, S.; Khakimova, O.; Koch, I.; Kren, F.; Kullander, S.; Kupść, A.; Lindberg, K.; Marciniewski, P.; Morosov, B.; Pauly, C.; Petukhov, Y.; Povtorejko, A.; Schönning, K.; Scobel, W.; Skorodko, T.; Stepaniak, J.; Tegnér, P.-E.; Thörngren Engblom, P.; Tikhomirov, V.; Wilkin, C.; Wolke, M.; Zabierowski, J.; Zartova, I.; Złomańczuk, J.

    2010-11-01

    The production of η mesons in proton-proton collisions has been studied using the WASA detector at the CELSIUS storage ring at excess energies of Q=40 MeV and Q=72 MeV. The η was detected through its 2γ decay in a near-4π electromagnetic calorimeter, whereas the protons were measured by a combination of straw chambers and plastic scintillator planes in the forward hemisphere. About 6.9×104 and 9.3×104 events were found at Q=40 MeV and Q=72 MeV, respectively, with background contributions of less than 5%. A simple parametrization of the production cross section in terms of low partial waves was used to evaluate the acceptance corrections. Strong evidence was found for the influence of higher partial waves. The Dalitz plots show the presence of p waves in both the pp and the η{pp} systems and the angular distributions of the η in the center-of-mass frame suggest the influence of d-wave η mesons.

  17. Energy dependence of fission product yields from 235U, 238U, and 239Pu with monoenergetic neutrons between thermal and 14.8 MeV

    Science.gov (United States)

    Gooden, Matthew; Arnold, Charles; Bhike, Megha; Bredeweg, Todd; Fowler, Malcolm; Krishichayan; Tonchev, Anton; Tornow, Werner; Stoyer, Mark; Vieira, David; Wilhelmy, Jerry

    2017-09-01

    Under a joint collaboration between TUNL-LANL-LLNL, a set of absolute fission product yield measurements has been performed. The energy dependence of a number of cumulative fission product yields (FPY) have been measured using quasi-monoenergetic neutron beams for three actinide targets, 235U, 238U and 239Pu, between 0.5 and 14.8 MeV. The FPYs were measured by a combination of fission counting using specially designed dual-fission chambers and γ-ray counting. Each dual-fission chamber is a back-to-back ionization chamber encasing an activation target in the center with thin deposits of the same target isotope in each chamber. This method allows for the direct measurement of the total number of fissions in the activation target with no reference to the fission cross-section, thus reducing uncertainties. γ-ray counting of the activation target was performed on well-shielded HPGe detectors over a period of two months post irradiation to properly identify fission products. Reported are absolute cumulative fission product yields for incident neutron energies of 0.5, 1.37, 2.4, 3.6, 4.6, 5.5, 7.5, 8.9 and 14.8 MeV. Preliminary results from thermal irradiations at the MIT research reactor will also be presented and compared to present data and evaluations. This work was performed under the auspices of the U.S. Department of Energy by Los Alamos National Security, LLC under contract DE-AC52-06NA25396, Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344 and by Duke University and Triangle Universities Nuclear Laboratory through NNSA Stewardship Science Academic Alliance grant No. DE-FG52-09NA29465, DE-FG52-09NA29448 and Office of Nuclear Physics Grant No. DE-FG02-97ER41033.

  18. Bremsstrahlung production at 50 MeV in different target materials and configurations.

    Science.gov (United States)

    Sätherberg, A; Andreo, P; Karlsson, M

    1996-04-01

    A combination of Monte Carlo, convolution, and experimental techniques have been used to investigate bremsstrahlung production at 50 MeV in full-range targets to produce narrow elementary photon beams for scanning. Calculations using the ITS 3.0 Monte Carlo system for various target designs, including particle transport through the treatment head of an MM5O racetrack microtron and a water phantom, have been compared to experimental dose profiles from narrow photon beams at 10-cm depth in water. A reduction in the ITS 3.0 default substep size has been found necessary even for incomplete agreement, in consistency with the findings of Faddegon and Rogers [Nucl. Instrum. Meth. A 327, 556-565 (1993)] for a different experimental setup and energy using the previous version of ITS. Results show that the calculated shape of the tail of dose distributions from narrow photon beams agrees well with measurements, but CYLTRAN/ITS 3.0 fails to reproduce the central part of the distribution. The discrepancy at small angles, reported previously for EGS4 and ITS 2.1 simulations, possess a limitation to Monte Carlo simulations of narrow photon beams used in scanned systems of clinical accelerators. Radial dose profiles have been calculated by convolution of the energy fluence at the exit of the target with one polyenergetic Monte Carlo calculated dose kernel and also a database consisting of ten different dose kernels corresponding to different monoenergetic photon pencil beams for comparison. The agreement with the much slower fully detailed Monte Carlo calculations was better when using the database kernels than the polyenergetic kernel. Results for the mean energy, mean polar angle, and energy fluence at different depths within various targets have been obtained. These are discussed in the context of the design characteristics of bremsstrahlung targets with emphasis on their utilization for scanning photon beam techniques.

  19. Production of Highly Polarized Positrons Using Polarized Electrons at MeV Energies

    Science.gov (United States)

    Abbott, D.; Adderley, P.; Adeyemi, A.; Aguilera, P.; Ali, M.; Areti, H.; Baylac, M.; Benesch, J.; Bosson, G.; Cade, B.; Camsonne, A.; Cardman, L. S.; Clark, J.; Cole, P.; Covert, S.; Cuevas, C.; Dadoun, O.; Dale, D.; Dong, H.; Dumas, J.; Fanchini, E.; Forest, T.; Forman, E.; Freyberger, A.; Froidefond, E.; Golge, S.; Grames, J.; Guèye, P.; Hansknecht, J.; Harrell, P.; Hoskins, J.; Hyde, C.; Josey, B.; Kazimi, R.; Kim, Y.; Machie, D.; Mahoney, K.; Mammei, R.; Marton, M.; McCarter, J.; McCaughan, M.; McHugh, M.; McNulty, D.; Mesick, K. E.; Michaelides, T.; Michaels, R.; Moffit, B.; Moser, D.; Muñoz Camacho, C.; Muraz, J.-F.; Opper, A.; Poelker, M.; Réal, J.-S.; Richardson, L.; Setiniyaz, S.; Stutzman, M.; Suleiman, R.; Tennant, C.; Tsai, C.; Turner, D.; Ungaro, M.; Variola, A.; Voutier, E.; Wang, Y.; Zhang, Y.; PEPPo Collaboration

    2016-05-01

    The Polarized Electrons for Polarized Positrons experiment at the injector of the Continuous Electron Beam Accelerator Facility has demonstrated for the first time the efficient transfer of polarization from electrons to positrons produced by the polarized bremsstrahlung radiation induced by a polarized electron beam in a high-Z target. Positron polarization up to 82% have been measured for an initial electron beam momentum of 8.19 MeV /c , limited only by the electron beam polarization. This technique extends polarized positron capabilities from GeV to MeV electron beams, and opens access to polarized positron beam physics to a wide community.

  20. Position measurements for the isotope production facility and the switchyard kicker upgrade projects

    Energy Technology Data Exchange (ETDEWEB)

    Gilpatrick, J. D. (John Douglas); Barr, D. S. (Dean S.); O' Hara, J. F. (James F.); Shurter, R. B. (Robert B.); Stettler, M. W. (Matthew W.); Martinez, D. G. (Derwin G.)

    2003-01-01

    The Los Alamos Neutron Science Center (LANSCE) is installing two beam lines to both improve operational tuning and provide new capabilities within the facility. The Isotope Production Facility (IPF) will provide isotopes for medical purposes by using the H' beam spur at 100 MeV and the Switchyard Kicker Upgrade (SYK) will allow the LANSCE 800-MeV H beam to be rapidly switched between various beam lines within the facility. The beam position measurements for both of these beam lines uses a standard micro-stripline beam position monitor (BPM) with both a 50-mm and 75-mm radius. The cable plant is unique in that it unambiguously provides a method of verifying the operation of the complete position measurement. The processing electronics module uses a log ratio technique with error corrections such that it has a dynamic range of -12 dBm to -85 dBm with errors less than 0.15 dB within this range. This paper will describe the primary components of these measurement systems and provide initial data of their operation.

  1. Helium production cross section Measurement of Pb and Sn for 14.9 MeV neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Takao, Yoshiyuki; Fujimoto, Toshihiro; Ozaki, Shuji; Muramasu, Masatomo; Nakashima, Hideki [Kyushu Univ., Fukuoka (Japan); Kanda, Yukinori; Ikeda, Yujiro

    1998-03-01

    Helium production cross sections of lead and tin for 14.9 MeV neutrons were measured by helium accumulation method. Lead and tin samples were irradiated with FNS, an intense d-T neutron source of JAERI. The amount of helium produced in the samples by the neutron irradiation was measured with the Helium Atoms Measurement System (HAMS) at Kyushu University. As the samples contained a small amount of helium because of their small helium production cross sections at 14.9 MeV, the samples were evaporated by radiation from a tungsten filament to decrease background gases at helium measurement. Uncertainties of the present results were less than {+-}4.4%. The results were compared with other experimental data in the literature and also compared with the evaluated values in JENDL-3.2. (author)

  2. Isotope Production at the Hanford Site in Richland, Washington

    Energy Technology Data Exchange (ETDEWEB)

    Ammoniums

    1999-06-01

    This report was prepared in response to a request from the Nuclear Energy Research Advisory Committee (NERAC) subcommittee on ''Long-Term Isotope Research and Production Plans.'' The NERAC subcommittee has asked for a reply to a number of questions regarding (1) ''How well does the Department of Energy (DOE) infrastructure sme the need for commercial and medical isotopes?'' and (2) ''What should be the long-term role of the federal government in providing commercial and medical isotopes?' Our report addresses the questions raised by the NERAC subcommittee, and especially the 10 issues that were raised under the first of the above questions (see Appendix). These issues are related to the isotope products offered by the DOE Isotope Production Sites, the capabilities and condition of the facilities used to produce these products, the management of the isotope production programs at DOE laboratories, and the customer service record of the DOE Isotope Production sites. An important component of our report is a description of the Fast Flux Test Facility (FFTF) reactor at the Hbford Site and the future plans for its utilization as a source of radioisotopes needed by nuclear medicine physicians, by researchers, and by customers in the commercial sector. In response to the second question raised by the NERAC subcommittee, it is our firm belief that the supply of isotopes provided by DOE for medical, industrial, and research applications must be strengthened in the near future. Many of the radioisotopes currently used for medical diagnosis and therapy of cancer and other diseases are imported from Canada, Europe, and Asia. This situation places the control of isotope availability, quality, and pricing in the hands of non-U.S. suppliers. It is our opinion that the needs of the U.S. customers for isotopes and isotope products are not being adequately served, and that the DOE infrastructure and facilities devoted to the

  3. Production of positive pions by 800 MeV protons on carbon

    Science.gov (United States)

    Denes, Peter; Dieterle, B. D.; Wolfe, D. M.; Bowles, T.; Dombeck, T.; Simmons, J. E.; Bhatia, T. S.; Glass, G.; Tippens, W. B.

    1983-03-01

    The double differential cross section for the reaction p+C-->π++X has been measured at laboratory angles of 7°, 15°, 20°, and 30°. NUCLEAR REACTIONS E=800 MeV, p+12C-->π++X measured dσdEπ for θπ=7°, 15°, 20°, 30°.

  4. 225Ac and 223Ra production via 800 MeV proton irradiation of natural thorium targets.

    Science.gov (United States)

    Weidner, J W; Mashnik, S G; John, K D; Ballard, B; Birnbaum, E R; Bitteker, L J; Couture, A; Fassbender, M E; Goff, G S; Gritzo, R; Hemez, F M; Runde, W; Ullmann, J L; Wolfsberg, L E; Nortier, F M

    2012-11-01

    Cross sections for the formation of (225,227)Ac, (223,225)Ra, and (227)Th via the proton bombardment of natural thorium targets were measured at a nominal proton energy of 800 MeV. No earlier experimental cross section data for the production of (223,225)Ra, (227)Ac and (227)Th by this method were found in the literature. A comparison of theoretical predictions with the experimental data shows agreement within a factor of two. Results indicate that accelerator-based production of (225)Ac and (223)Ra is a viable production method.

  5. K X-ray production by 3-4 MeV proton impact on selected lanthanoids

    Energy Technology Data Exchange (ETDEWEB)

    Reyes-Herrera, J. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 20-364, 01000 Mexico, D.F. (Mexico); Miranda, J., E-mail: miranda@fisica.unam.m [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 20-364, 01000 Mexico, D.F. (Mexico)

    2010-10-15

    Measurements of K-shell X-ray production cross sections induced by proton beams with energies between 3 MeV and 4 MeV are presented. The studied elements were Ce, Nd, Gd, Dy, and Ho, as thick targets. The measured cross sections are evaluated through comparisons with the ECPSSR model, the eECPSShsR-UA theory, the adiabatic perturbation (also known as direct molecular orbital, or MO) theory, and the empirical fits of Kahoul et al. using a scaling based on the reduced velocity parameter {xi}{sub K}{sup R} in every case. Consideration is given to multiple ionization effects and electron capture contribution to K-shell ionization. It is shown that the experimental results are in good agreement with the theoretical predictions in the whole measured {xi}{sub K}{sup R} range.

  6. Proton-induced cross sections relevant to production of 225Ac and 223Ra in natural thorium targets below 200 MeV

    CERN Document Server

    Weidner, J W; John, K D; Hemez, F; Ballard, B; Bach, H; Birnbaum, E R; Bitteker, L J; Couture, A; Dry, D; Fassbender, M E; Gulley, M S; Jackman, K R; Ullmann, J L; Wolfsberg, L E; Nortier, F M

    2012-01-01

    Cross sections for 223,225Ra, 225Ac and 227Th production by the proton bombardment of natural thorium targets were measured at proton energies below 200 MeV. Our measurements are in good agreement with previously published data and offer a complete excitation function for 223,225Ra in the energy range above 90 MeV. Comparison of theoretical predictions with the experimental data shows reasonable-to-good agreement. Results indicate that accelerator-based production of 225Ac and 223Ra below 200 MeV is a viable production method.

  7. Proton-induced cross sections relevant to production of 225Ac and 223Ra in natural thorium targets below 200 MeV.

    Science.gov (United States)

    Weidner, J W; Mashnik, S G; John, K D; Hemez, F; Ballard, B; Bach, H; Birnbaum, E R; Bitteker, L J; Couture, A; Dry, D; Fassbender, M E; Gulley, M S; Jackman, K R; Ullmann, J L; Wolfsberg, L E; Nortier, F M

    2012-11-01

    Cross sections for (223,)(225)Ra, (225)Ac and (227)Th production by the proton bombardment of natural thorium targets were measured at proton energies below 200 MeV. Our measurements are in good agreement with previously published data and offer a complete excitation function for (223,)(225)Ra in the energy range above 90 MeV. Comparison of theoretical predictions with the experimental data shows reasonable-to-good agreement. Results indicate that accelerator-based production of (225)Ac and (223)Ra below 200 MeV is a viable production method.

  8. Commissioning and initial operation of the Isotope Production Facility at the Los Alamos Neutron Science Center (LANSCE).

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, K. F. (Kenneth F.); Alvestad, H. W. (Henry W.); Barkley, W. C. (Walter C.); Barlow, D. B. (David B.); Barr, D. S. (Dean S.); Bennett, L. S. (Langdon S.); Bitteker, L. J. (Leo J.); Bjorklund, E. A. (Eric A.); Boedeker, W.; Borden, M. J. (Michael J.); Cardon, R.; Carr, G. (Gary); Casados, J. L. (Jeffrey L.); Cohen, Stanley; Cordova, J. F. (Justo J.; Faucett, John Allen,; Fresquez, M. (Matthew); Gallegos, F. R. (Floyd R.); Gilpatrick, J. D. (John Douglas); Gonzales, F. (Fermin); Gorman, F. W. (Frederick W.); Gulley, M. S. (Mark S.); Hall, M. J. (Michael J.); Hayden, D. J. (David J.); Heaton, R. C. (Richard C.); Henderson, D. B. (Dale B.); Ireland, D. B. (David B.); Jacobson, E. G. (Edward G.); Johns, G. D. (Glen D.); Kersteins, D. M. (Debora M.); Maestas, A. J. (Alfred J.); Martinez, A. M. (Alexandra M.); Martinez, D. G. (Derwin G.); Martinez, G.; Martinez, J.; Martinez, M. P. (Martin P.); Merl, R. B. (Robert B.); Merrill, J. B. (John B.); Meyer, B. J. (Bruce J.); Meyer, R., Sr.; Milder, M.; Morgan, E.; Nortier, M.; O' Hara, J. F. (James F.); Olivas, F. R. (Felix R.); Oothoudt, Michael; Pence, T. D. (Tim D.); Perets, Mikhaʾel ben Yosef; Peterson, E.; Pillai, C. (Chandra); Romero, F.; Rose, C.; Rybarcyk, L. J. (Lawrence J.); Sanchez, G. (Gary); Sandoval, J. B. (Jacob B.); Schaller, S. (Stuart); Shelley, F. E. (Fred E.); Shurter, R. B. (Robert B.); Sommer, Walter F.; Stettler, M. W. (Matthew W.); Stockton, J. L. (Jerry L.); Sturrock, J. C. (James C.); Tomei, T. L. (Tony L.); Valdez, F.; Vigil, V. P. (Victor P.); Walstrom, P. L. (Peter L.); Wanco, P. M. (Peter M.); Wilmarth, J.

    2004-01-01

    The recently completed 100-MeV H{sup +} Isotope Production Facility (IPF) at the LANSCE will provide radioisotopes for medical research and diagnosis, for basic research and for commercial use. A change to the LANSCE accelerator facility allowed for the installation of the IPF. Three components make up the LANSCE accelerator: an injector that accelerates the H{sup +} beam to 750-KeV, a drift-tube linac (DTL) that increases the beam energy to 100-MeV, and a side-coupled cavity linac (SCCL) that accelerates the beam to 800-MeV. The transition region, a space between the DTL and the SCCL, was modified to permit the insertion of a kicker magnet (23{sup o} kick angle) for the purpose of extracting a portion of the 100-MeV H{sup +} beam. A new beam line was installed to transport the extracted H{sup +} beam to the radioisotope production target chamber. This paper will describe the commissioning and initial operating experiences of IPF.

  9. Production of highly-polarized positrons using polarized electrons at MeV energies

    CERN Document Server

    Abbott, D; Adeyemi, A; Aguilera, P; Ali, M; Areti, H; Baylac, M; Benesch, J; Bosson, G; Cade, B; Camsonne, A; Cardman, L S; Clark, J; Cole, P; Covert, S; Cuevas, C; Dadoun, O; Dale, D; Dong, H; Dumas, J; Fanchini, E; Forest, T; Forman, E; Freyberger, A; Froidefond, E; Golge, S; Grames, J; Guèye, P; Hansknecht, J; Harrell, P; Hoskins, J; Hyde, C; Josey, B; Kazimi, R; Kim, Y; Machie, D; Mahoney, K; Mammei, R; Marton, M; McCarter, J; McCaughan, M; McHugh, M; McNulty, D; Mesick, K E; Michaelides, T; Michaels, R; Moffit, B; Moser, D; Camacho, C Muñoz; Muraz, J -F; Opper, A; Poelker, M; Réal, J -S; Richardson, L; Setiniyaz, S; Stutzman, M; Suleiman, R; Tennant, C; Tsai, C; Turner, D; Ungaro, M; Variola, A; Voutier, E; Wang, Y; Zhang, Y

    2016-01-01

    The Polarized Electrons for Polarized Positrons experiment at the injector of the Continuous Electron Beam Accelerator Facility has demonstrated for the first time the efficient transfer of polarization from electrons to positrons produced by the polarized bremsstrahlung radiation induced by a polarized electron beam in a high-$Z$ target. Positron polarization up to 82\\% have been measured for an initial electron beam momentum of 8.19~MeV/$c$, limited only by the electron beam polarization. This technique extends polarized positron capabilities from GeV to MeV electron beams, and opens access to polarized positron beam physics to a wide community.

  10. Evaluation Study for the Production of the Medical Isotope ^90Y, using a Cyclotron

    Science.gov (United States)

    Necsoiu, D.; Morgan, I. L.; Hupf, Homer; Armbruster, J.; Boyce, D.; El Bouanani, M.; McDaniel, F. D.

    2000-10-01

    The use of radioisotopes in therapy, medical imaging and laboratory tests is well-established worldwide. ^90Y is a very good therapeutic candidate for radioimmunotherapy applications. Traditionally, medical radioisotopes are produced using either nuclear reactors or proton accelerators. In this study, the medical isotope ^90Y has been produced using ^90Zr(n,p)^90Y nuclear reaction. Neutrons for the activation process were produced using ^natRh(p,xn) reaction with a 27 MeV proton beam from a cyclotron. Since ^90Y is a pure beta emitter, the gamma rays from the ^90Zr(n,2n)^89Zr reaction were used to quantify the incident neutron flux on the ^90Zr sample. Experimental results of the neutron production and ^90Y activity are presented.

  11. Comparison of neutron cross sections for selected fission products and isotopic composition analyses with burnup

    Energy Technology Data Exchange (ETDEWEB)

    Kim, D. H.; Gil, C. S.; Kim, J. D.; Jang, J. H.; Lee, Y. D. [KAERI, Taejon (Korea)

    2003-10-01

    The neutron absorption cross sections for 18 fission products evaluated within the framework of the KAERI-BNL international collaboration have been compared with the ENDF/B-VI release 7. Also, the influence of the new evaluations on isotopic compositions of the fission products as a function of burnup has been analyzed through the OECD/NEA burnup credit criticality benchmarks (Phase 1B) and the LWR/Pu recycling benchmarks. These calculations were performed by WIMSD-5B with the 69 group libraries prepared from three evaluated nuclear data libraries: ENDF/B-VI.7, ENDF/B-VI.8 including new evaluations in resonance region covering thermal region, and ENDF/B-VII expected including those in upper resonance region up to 20 MeV. For Xe-131, the composition calculated with ENDF/B-VI.8 shows maximum difference of 4.78% compared to ENDF/B-VI.7. However, the isotopic compositions of all fission products calculated with ENDF/B-VII shows no differences compared to ENDF/B-VI.7.

  12. Comparisons of Neutron Cross Sections and Isotopic Composition Calculations for Fission-Product Evaluations

    Science.gov (United States)

    Kim, Do Heon; Gil, Choong-Sup; Chang, Jonghwa; Lee, Yong-Deok

    2005-05-01

    The neutron absorption cross sections for 18 fission products evaluated within the framework of the KAERI (Korea Atomic Energy Research Institute)-BNL (Brookhaven National Laboratory) international collaboration have been compared with ENDF/B-VI.7. Also, the influence of the new evaluations on the isotopic composition calculations of the fission products has been estimated through the OECD/NEA burnup credit criticality benchmarks (Phase 1B) and the LWR/Pu recycling benchmarks. These calculations were performed by WIMSD-5B with the 69-group libraries prepared from three evaluated nuclear data libraries: ENDF/B-VI.7, ENDF/B-VI.8 including the new evaluations in the resonance region covering the thermal region, and the expected ENDF/B-VII including those in the upper resonance region up to 20 MeV. For Xe-131, the composition calculated with ENDF/B-VI.8 shows a maximum difference of 5.02% compared to ENDF/B-VI.7. However, the isotopic compositions of all the fission products calculated with the expected ENDF/B-VII show no differences when compared to ENDF/B-VI.7 for the thermal reactor benchmark cases.

  13. Determination of relative krypton fission product yields from 14 MeV neutron induced fission of 238U at the National Ignition Facility

    Science.gov (United States)

    Edwards, E. R.; Cassata, W. S.; Velsko, C. A.; Yeamans, C. B.; Shaughnessy, D. A.

    2016-11-01

    Precisely-known fission yield distributions are needed to determine a fissioning isotope and the incident neutron energy in nuclear security applications. 14 MeV neutrons from DT fusion at the National Ignition Facility induce fission in depleted uranium contained in the target assembly hohlraum. The fission yields of Kr isotopes (85m, 87, 88, and 89) are measured relative to the cumulative yield of 88Kr and compared to previously tabulated values. The results from this experiment and England and Rider are in agreement, except for the 85mKr/88Kr ratio, which may be the result of incorrect nuclear data.

  14. Production of stable isotopes utilizing the plasma separation process

    Science.gov (United States)

    Bigelow, T. S.; Tarallo, F. J.; Stevenson, N. R.

    2005-12-01

    A plasma separation process (PSP) is being operated at Theragenics Corporation's®, Oak Ridge, TN, facility for the enrichment of stable isotopes. The PSP utilizes ion cyclotron mass discrimination to separate isotopes on a relatively large scale. With a few exceptions, nearly any metallic element could be processed with PSP. Output isotope enrichment factor depends on natural abundance and mass separation and can be fairly high in some cases. The Theragenics™ PSP facility is believed to be the only such process currently in operation. This system was developed and formerly operated under the US Department of Energy Advanced Isotope Separation program. Theragenics™ also has a laboratory at the PSP site capable of harvesting the isotopes from the process and a mass spectrometer system for analyzing enrichment and product purity. Since becoming operational in 2002, Theragenics™ has utilized the PSP to separate isotopes of several elements including: dysprosium, erbium, gadolinium, molybdenum and nickel. Currently, Theragenics™ is using the PSP for the separation of 102Pd, which is used as precursor for the production of 103Pd. The 103Pd radioisotope is the active ingredient in TheraSeed®, which is used in the treatment of early stage prostate cancer and being investigated for other medical applications. New industrial, medical and research applications are being investigated for isotopes that can be enriched on the PSP. Pre-enrichment of accelerator or reactor targets offers improved radioisotope production. Theragenics operates 14 cyclotrons for proton activation and has access to HFIR at ORNL for neutron activation of radioisotopes.

  15. A proposed standard on medical isotope production in fission reactors

    Energy Technology Data Exchange (ETDEWEB)

    Schenter, R. E. [Smart Bullets Inc., 2521 SW Luradel Street, Portland, OR 97219 (United States); Brown, G. J. [Ozarks Medical Center, Cancer Treatment Center, Shaw Medical Building, 1111 Kentucky Avenue, West Plains, MO 65775 (United States); Holden, C. S. [Thorenco LLC, 369 Pine Street, San Francisco, CA 94104 (United States)

    2006-07-01

    Authors Robert E. Sehenter, Garry Brown and Charles S. Holden argue that a Standard for 'Medical Isotope Production' is needed. Medical isotopes are becoming major components of application for the diagnosis and treatment of all the major diseases including all forms of cancer, heart disease, arthritis, Alzheimer's, among others. Current nuclear data to perform calculations is incomplete, dated or imprecise or otherwise flawed for many isotopes that could have significant applications in medicine. Improved data files will assist computational analyses to design means and methods for improved isotope production techniques in the fission reactor systems. Initial focus of the Standard is expected to be on neutron cross section and branching data for both fast and thermal reactor systems. Evaluated and reviewed tables giving thermal capture cross sections and resonance integrals for the major target and product medical isotopes would be the expected 'first start' for the 'Standard Working Group'. (authors)

  16. This picture was taken in 1967 during the first test of the Isotope On-Line Separator (ISOLDE) installation at the 600 MeV CERN Synchro Cyclotron.

    CERN Multimedia

    CERN PhotoLab

    1967-01-01

    When ISOLDE began operation, it was unique in the world. It used a new technique to overcome the problem of rapidly separating interesting atoms from the rest of the nuclear target. Through a combination of chemical and electromagnetic methods the different isotopes were separated and converted into an ion beam made of just one isotope. On-line production of radioactive nuclei, in this way, offered many new opportunities for physicists as it allowed them to perform previously impossible experiments on short-lived nuclei. ISOLDE has become one of CERN's major installations and it supports a broad scientific programme by providing beams to different experiments. The techniques developed at ISOLDE have opened up a new field of radioactive ion-beam accelerators, both at CERN and worldwide.

  17. Photo-fission Product Yield Measurements at Eγ=13 MeV on 235U, 238U, and 239Pu

    Science.gov (United States)

    Tornow, W.; Bhike, M.; Finch, S. W.; Krishichayan, Fnu; Tonchev, A. P.

    2016-09-01

    We have measured Fission Product Yields (FPYs) in photo-fission of 235U, 238U, and 239Pu at TUNL's High-Intensity Gamma-ray Source (HI γS) using mono-energetic photons of Eγ = 13 MeV. Details of the experimental setup and analysis procedures will be discussed. Yields for approximately 20 fission products were determined. They are compared to neutron-induced FPYs of the same actinides at the equivalent excitation energies of the compound nuclear systems. In the future photo-fission data will be taken at Eγ = 8 . 0 and 10.5 MeV to find out whether photo-fission exhibits the same so far unexplained dependence of certain FPYs on the energy of the incident probe, as recently observed in neutron-induced fission, for example, for the important fission product 147Nd. Work supported by the U. S. Dept. of Energy, under Grant No. DE-FG02-97ER41033, and by the NNSA, Stewardship Science Academic Alliances Program, Grant No. DE-NA0001838 and the Lawrence Livermore, National Security, LLC under Contract No. DE-AC52-07NA27344.

  18. Calculation of in-target production rates for radioactive isotope beam production at TRIUMF

    Science.gov (United States)

    Garcia, Fatima; Andreoiu, Corina; Kunz, Peter; Laxdal, Aurelia

    2016-09-01

    Rare Isotope Beam (RIB) facilities around the world, such as TRIUMF, work towards development of new target materials to generate exotic species. Access to these rare radioactive isotopes is key for applications in nuclear medicine, astrophysics and fundamental nuclear science. To better understand production from these and other materials, we have built a computer simulation of the RIB targets used at the TRIUMF Isotope Separation and ACceleration (ISAC) facility, to support new target material development. Built at Simon Fraser University, the simulation runs in the GEANT4 nuclear transport toolkit, and can simulate the production rate of isotopes from a given set of beam and target characteristics. The simulation models the bombardment of a production target by an incident high-energy proton beam and calculates isotope in-target production rates different nuclear reactions. Results from the simulation will be presented, along with an evaluation of various nuclear reaction models and a experimentally determined RIB yields at the ISAC Yield Station.

  19. Efficient production and diagnostics of MeV proton beams from a cryogenic hydrogen ribbon

    Science.gov (United States)

    Velyhan, A.; Giuffrida, L.; Scuderi, V.; Perin, J. P.; Chatain, D.; Garcia, S.; Bonnay, P.; Dostal, J.; Ullschmied, J.; Dudzak, R.; Krousky, E.; Cykhardt, J.; Prokupek, J.; Pfeifer, M.; Rosinski, M.; Krasa, J.; Brabcova, K.; De Napoli, M.; Lastovicka, T.; Margarone, D.

    2017-06-01

    A solid hydrogen thin ribbon, produced by the cryogenic system ELISE (Experiments on Laser Interaction with Solid hydrogEn) target delivery system, was experimentally used at the PALS kJ-laser facility to generate intense proton beams with energies in the MeV range. This sophisticated target system operating at cryogenic temperature (~ 10 K) continuously producing a 62 μm thick target was combined with a 600 J sub-nanosecond laser pulse to generate a collimated proton stream. The accelerated proton beams were fully characterized by a number of diagnostics. High conversion efficiency of laser to energetic protons is of great interest for future potential applications in non-conventional proton therapy and fast ignition for inertial confinement fusion.

  20. Production of waveguides in LiF by MeV ion bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, J.A.M. [USP, Institute of Physics, CP 66318, 05315-970 Sao Paulo, SP (Brazil)]. E-mail: jamp@fge.if.usp.br; Cremona, M. [PUC-Rio, Physics Department, CP 38071, 22452-970 Rio de Janeiro, RJ (Brazil); Pelli, S. [Nello Carrara Institute of Applied Physics - CNR, Optoelectronics and Photonics Department, via Panciatichi 64, 50127 Firenze (Italy); Macchione, E.L.A. [USP, Institute of Physics, CP 66318, 05315-970 Sao Paulo, SP (Brazil); Koide, K. [USP, Institute of Physics, CP 66318, 05315-970 Sao Paulo, SP (Brazil); Vasconcelos, S.S. [USP, Institute of Physics, CP 66318, 05315-970 Sao Paulo, SP (Brazil); Righini, G.C. [Nello Carrara Institute of Applied Physics - CNR, Optoelectronics and Photonics Department, via Panciatichi 64, 50127 Florence (Italy)

    2005-10-15

    Alkali fluorides containing color centers are promising systems for applications in new integrated optical devices like active waveguides and color center lasers. In this work, we report the development of a simple method, based on high-energy ion beam irradiation, to create active waveguides in alkali halide materials. MeV carbon and helium beams at normal incidence were used to irradiate lithium fluoride crystals, with different ion doses varying from 10{sup 14} up to 10{sup 16} cm{sup -2}, producing thin colored strips. Irradiated waveguides were also characterized by means of optical absorption spectroscopy in order to obtain the distribution of the color centers induced by the ion beam. The results confirm the feasibility of integrated active devices based on color centers in LiF such as tunable light amplifiers, lasers and hybrid optoelectronic components.

  1. Development of stable isotope separation technology for radioisotope production

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Do Young; Kim, Cheol Jung; Park, Kyung Bae [and others

    2003-05-01

    The ultimate goal of this project is to construct the domestic production system of stable isotopes O-18 and Tl-203 used as target materials in accelerator for the production of medical radioisotopes F-18 and Tl-201, respectively. In order to achieve this goal, diode laser spectroscopic analytical system was constructed and automatic measurement computer software for the direct analysis of H{sub 2}{sup 16}O/H{sub 2}{sup 18}O ratio were developed. Distillation process, laser process, and membrane diffusion process were analyzed for the evaluation of O-18 production. And electromagnetic process, plasma process, and laser process were analyzed for the evaluation of Tl-203 production. UV laser system, IR laser system, and detailed system Tl-203 production were designed. Finally, current and future worldwide demand/supply of stable isotopes O-18 and Tl-203 were estimated.

  2. Medical Isotope Production Analyses In KIPT Neutron Source Facility

    Energy Technology Data Exchange (ETDEWEB)

    Talamo, Alberto [Argonne National Lab. (ANL), Argonne, IL (United States); Gohar, Yousry [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-01-01

    Medical isotope production analyses in Kharkov Institute of Physics and Technology (KIPT) neutron source facility were performed to include the details of the irradiation cassette and the self-shielding effect. An updated detailed model of the facility was used for the analyses. The facility consists of an accelerator-driven system (ADS), which has a subcritical assembly using low-enriched uranium fuel elements with a beryllium-graphite reflector. The beryllium assemblies of the reflector have the same outer geometry as the fuel elements, which permits loading the subcritical assembly with different number of fuel elements without impacting the reflector performance. The subcritical assembly is driven by an external neutron source generated from the interaction of 100-kW electron beam with a tungsten target. The facility construction was completed at the end of 2015, and it is planned to start the operation during the year of 2016. It is the first ADS in the world, which has a coolant system for removing the generated fission power. Argonne National Laboratory has developed the design concept and performed extensive design analyses for the facility including its utilization for the production of different radioactive medical isotopes. 99Mo is the parent isotope of 99mTc, which is the most commonly used medical radioactive isotope. Detailed analyses were performed to define the optimal sample irradiation location and the generated activity, for several radioactive medical isotopes, as a function of the irradiation time.

  3. Compton-Pair Production Space Telescope (ComPair) for MeV Gamma-ray Astronomy

    CERN Document Server

    Moiseev, A A; Buckley, J H; Caputo, R; Ferrara, E C; Hartmann, D H; Hays, E; McEnery, J E; Mitchell, J W; Ojha, R; Perkins, J S; Racusin, J L; Smith, A W; Thompson, D J

    2015-01-01

    The gamma-ray energy range from a few hundred keV to a few hundred MeV has remained largely unexplored, mainly due to the challenging nature of the measurements, since the pi- oneering, but limited, observations by COMPTEL on the Compton Gamma-Ray Observatory (1991-2000). This energy range is a transition region between thermal and nonthermal processes, and accurate measurements are critical for answering a broad range of astrophysical questions. We are developing a MIDEX-scale wide-aperture discovery mission, ComPair (Compton-Pair Production Space Telescope), to investigate the energy range from 200 keV to > 500 MeV with high energy and angular resolution and with sensitivity approaching a factor of 100 better than COMPTEL. This instrument will be equally capable to detect both Compton-scattering events at lower energy and pair-production events at higher energy. ComPair will build on the her- itage of successful space missions including Fermi LAT, AGILE, AMS and PAMELA, and will utilize well-developed space...

  4. Medical-isotope supply hit by production problems

    Science.gov (United States)

    Gould, Paula

    2008-10-01

    A shortfall in the production of medical isotopes in Europe has forced hospitals to delay patient scans or offer alternative diagnostic tests. The problems began in August when all three nuclear reactors used to generate molybdenum-99, which then decays to form the key nuclear-imaging agent technetium-99, had to be unexpectedly shut down at the same time.

  5. 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...

  6. New Production Routes for Medical Isotopes 64Cu and 67Cu Using Accelerator Neutrons

    Science.gov (United States)

    Kin, Tadahiro; Nagai, Yasuki; Iwamoto, Nobuyuki; Minato, Futoshi; Iwamoto, Osamu; Hatsukawa, Yuichi; Segawa, Mariko; Harada, Hideo; Konno, Chikara; Ochiai, Kentaro; Takakura, Kosuke

    2013-03-01

    We have measured the activation cross sections producing 64Cu and 67Cu, promising medical radioisotopes for molecular imaging and radioimmunotherapy, by bombarding a natural zinc sample with 14 MeV neutrons. We estimated the production yields of 64Cu and 67Cu by fast neutrons from \\text{natC(d,n) with 40 MeV 5 mA deuterons. We used the present result together with the evaluated cross section of Zn isotopes. The calculated 64Cu yield is 1.8 TBq (175 g 64Zn) for 12 h of irradiation; the yields of 67Cu by 67Zn(n,p)67Cu and 68Zn(n,x)67Cu were 249 GBq (184 g 67Zn) and 287 GBq (186 g 68Zn) at the end of 2 days of irradiation, respectively. From the results, we proposed a new route to produce 67Cu with very little radionuclide impurity via the 68Zn(n,x)67Cu reaction, and showed the 64Zn(n,p)64Cu reaction to be a promising route to produce 64Cu. Both 67Cu and 64Cu are noted to be produced using fast neutrons.

  7. Production yields of {sup Nat}Zn(p,x){sup 67}Ga reaction in the energy range of 1.6 to 2.5 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Wachter, J A; Miranda, P A; Cancino, S A; Morales, J R; Dinator, M I [Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago (Chile)], E-mail: javier.wachter@gmail.com

    2008-11-01

    Production yield of the {sup 67}Ga (t{sub 1/2} = 78.3hr.)radionuclide was measured by the {sup Nat}Zn(p,x){sup 67} Ga reaction in the energy range from 1.6 to 2.5 MeV. These results are the first reported at energies under 3 MeV. The overall uncertainty of these measurements are around 7%.

  8. Production of neutral pions in heavy-ion collisions at Elab/A=25 MeV

    Science.gov (United States)

    Young, G. R.; Obenshain, F. E.; Plasil, F.; Braun-Munzinger, P.; Freifelder, R.; Paul, P.; Stachel, J.

    1986-02-01

    Inclusive production of neutral pions was observed at Elab/A=25 MeV in the reactions 16O+Al,Ni-->π0+X. Neutral pions were detected by observing their two decay γ rays in coincidence in an array of 20 Pb-glass Cerenkov-detector telescopes. An array of plastic Cerenkov detectors was added to the above array to tag and reject a significant cosmic-ray background. The observed cross sections are much larger than predicted by nucleon-nucleon collision or statistical models, even if cooperative action of target and projectile nucleons and cluster formation in the final channel are taken into account. This indicates the presence of a collective production mechanism.

  9. Production of neutral pions in heavy-ion collisions at E/sub lab//A = 25 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Young, G.R.; Obenshain, F.E.; Plasil, F.; Braun-Munzinger, P.; Freifelder, R.; Paul, P.; Stachel, J.

    1986-02-01

    Inclusive production of neutral pions was observed at E/sub lab//A = 25 MeV in the reactions WO+Al,Ni +X. Neutral pions were detected by observing their two decay el rays in coincidence in an array of 20 Pb-glass Cerenkov-detector telescopes. An array of plastic Cerenkov detectors was added to the above array to tag and reject a significant cosmic-ray background. The observed cross sections are much larger than predicted by nucleon-nucleon collision or statistical models, even if cooperative action of target and projectile nucleons and cluster formation in the final channel are taken into account. This indicates the presence of a collective production mechanism.

  10. Cusp electron production in Coincidence with Target Recoil Ions for 3 MeV C^+ + Ar Collisions

    Science.gov (United States)

    Wig, A. G.; Desai, D. D.; Breinig, M.

    1996-11-01

    The production cross section and energy distribution of ionized projectile electrons are measured in coincidence with the target recoil ion charge state for 3 MeV C^+ projectiles colliding with Ar. Evidence for the importance of the electron-electron interaction is sought in the dependence of the cross section on the target recoil ion charge state and the shape of the energy distribution as a function of recoil ion charge state. While the coincidence yields suggest that the projectile electron-target electron interaction produces a significant fraction of the cusp electrons which have energy < 1 eV in the projectile frame, the measured cusp shapes are independent of recoil ion charge state. This suggest that the cusp shape is independent of the production mechanism and depends only on the interaction of the cusp electron with the remaining projectile ion.

  11. Single \\pi^- production in np collisions for excess energies up to 90 MeV

    CERN Document Server

    Abdel-Bary, M; Clement, H; Doroshkevich, E; Dshemuchadse, S; Erhardt, A; Eyrich, W; Freiesleben, H; Gillitzer, A; Jäkel, R; Karsch, L; Kilian, K; Kuhlmann, E; Möller, K; Morsch, H P; Naumann, Lutz; Paul, N; Pizzolotto, C; Ritman, J; Roderburg, E; Schroeder, W; Schulte-Wissermann, M; Sefzick, Th; Teufel, A; Ucar, A; Wintz, P; Wüstner, P; Zupranski, P

    2007-01-01

    The quasifree reaction $np\\to pp\\pim$ was studied in a kinematically complete experiment by bombarding a liquid hydrogen target with a deuteron beam of momentum 1.85 GeV/c and analyzing the data along the lines of the spectator model. In addition to the three charged ejectiles the spectator proton was also detected in the large-acceptance time-of-flight spectrometer COSY-TOF. It was identified by its momentum and flight direction thus yielding access to the Fermi motion of the bound neutron and to the effective neutron 4-momentum vector $\\mathbb{P}_n$ which differed from event to event. A range of almost 90 MeV excess energy above threshold was covered. Energy dependent angular distributions, invariant mass spectra as well as fully covered Dalitz plots were deduced. Sizeable $pp$ FSI effects were found as were contributions of $p$ and $d$ partial waves. The behavior of the elementary cross section $\\sigma_{01}$ close to threshold is discussed in view of new cross section data. In comparison with existing lite...

  12. Single π- production in np collisions for excess energies up to 90 MeV

    Science.gov (United States)

    Abdel-Bary, M.; Brinkmann, K.-Th.; Clement, H.; Doroshkevich, E.; Dshemuchadse, S.; Erhardt, A.; Eyrich, W.; Freiesleben, H.; Gillitzer, A.; Jäkel, R.; Karsch, L.; Kilian, K.; Kuhlmann, E.; Möller, K.; Morsch, H. P.; Naumann, L.; Paul, N.; Pizzolotto, C.; Ritman, J.; Roderburg, E.; Schroeder, W.; Schulte-Wissermann, M.; Sefzick, Th.; Teufel, A.; Ucar, A.; Ullrich, W.; Wintz, P.; Wüstner, P.; Zupranski, P.

    2008-04-01

    The quasifree reaction nprightarrow ppπ- was studied in a kinematically complete experiment by bombarding a liquid-hydrogen target with a deuteron beam of momentum 1.85GeV/ c and analyzing the data along the lines of the spectator model. In addition to the three charged ejectiles the spectator proton was also detected in the large-acceptance time-of-flight spectrometer COSY-TOF. It was identified by its momentum and flight direction thus yielding access to the Fermi motion of the bound neutron and to the effective neutron 4-momentum vector mathbb {P} n which differed from event to event. A range of almost 90MeV excess energy above threshold was covered. Energy-dependent angular distributions, invariant-mass spectra as well as fully covered Dalitz plots were deduced. Sizeable pp FSI effects were found as were contributions of p and d partial waves. In comparison with existing literature data the results provide a sensitive test of the spectator model. The behavior of the elementary cross-section σ01 close to threshold is discussed in view of new cross-section data.

  13. Scoping assessment on medical isotope production at the Fast Flux Test Facility

    Energy Technology Data Exchange (ETDEWEB)

    Scott, S.W.

    1997-08-29

    The Scoping Assessment addresses the need for medical isotope production and the capability of the Fast Flux Test Facility to provide such isotopes. Included in the discussion are types of isotopes used in radiopharmaceuticals, which types of cancers are targets, and in what way isotopes provide treatment and/or pain relief for patients.

  14. Using Stable Isotopes to Trace Microbial Hydrogen Production Pathways

    Science.gov (United States)

    Moran, J.; Hill, E.; Bartholomew, R.; Yang, H.; Shi, L.; Ostrom, N. E.; Gandhi, H.; Hegg, E.; Kreuzer, H.

    2010-12-01

    Biological H2 production by hydrogenase enzymes (H2ases) plays an important role in anaerobic microbial metabolism and community structure. Despite considerable progress in elucidating H2 metabolism, the regulation of and flux through key H2 production pathways remain largely undefined. Our goal is to improve understanding of biological H2 production by using H isotope ratios to dissect proton fluxes through different H2ase enzymes and from different substrates. We hypothesized that the isotope ratio of H2 produced by various hydrogenases (H2ase) would differ, and that the H isotope ratios would allow us to define the contribution of different enzymes when more than one is present in vivo. We chose Shewanella oneidensis (S.o.) MR-1, a facultative anaerobe capable of transferring electrons to a variety of terminal acceptors, including protons, as a model system for in vivo studies. S. o. encodes one [FeFe]- and one [NiFe]-H2ase. We purified three [FeFe]-H2ases (S.o., Clostridium pasteurianum, and Chlamydomonas reinhardtii) and two [NiFe]-H2ases (S. o. and Desulfovibrio fructosovorans) to test the isotope fractionation associated with activity by each enzyme in vitro. For in vivo analysis we used wild-type S.o. as well as electron transfer-deficient and H2ase-deficient strains. We employed batch cultures using lactate as an electron donor and O2 as an initial electron acceptor (with H2 production after O2 consumption). The five H2ases we tested all had a unique isotope fractionation. Measurements of H2 produced in vivo showed distinct periods of H2 production having isotope signatures consistent with in vitro results. Isotope data as well as studies of H2 production by mutants in the genes encoding either the [NiFe]-H2ase or the [FeFe]-H2ase, respectively, show that the [NiFe]- and [FeFe]- H2ases became active at different times. The [NiFe]-H2ase both produces and consumes H2 before the [FeFe]-H2ase becomes active. RNA analysis is consistent with up regulation of

  15. Measurement of L X-ray production cross sections by impact of protons with energies between 2.5 MeV and 5.0 MeV in selected lanthanoids

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, J.; Murillo, G.; Mendez, B.; Lopez M, J.; Aspiazu, J.; Villasenor, P., E-mail: ghiraldo.murillo@inin.gob.mx [ININ, Departamento de Aceleradores, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2012-06-15

    Accurate quantitative analysis with particle induced X-ray emission (PIXE) requires an accurate knowledge of the X-ray production cross sections, in particular the L lines. While there are a lot of experimental results, recent reviews have found a disagreement between several previously published papers and also by the use of different atomic parameters databases (fluorescence yields and Coster-Kronig transition probabilities). Therefore, it is very convenient to redo some of these cross sections measurements and to extend to other proton energy ranges. Thus, this paper presents results with lanthanoid elements (Ce, Nd, Sm, Eu, Gd, Dy, Ho) irradiated with protons in the energy range 2.5 MeV to 5.0 MeV. The results are compared also with predictions of the ECPSSR theory with the United Atom modification and experimental data of other authors. (Author)

  16. Entropy production in the Au+Au reaction between 150A and 800A MeV

    Science.gov (United States)

    Kuhn, C.; Konopka, J.; Coffin, J. P.; Cerruti, C.; Fintz, P.; Guillaume, G.; Houari, A.; Jundt, F.; Maguire, C. F.; Rami, F.; Tezkratt, R.; Wagner, P.; Basrak, Z.; Čaplar, R.; Cindro, N.; Hölbling, S.; Alard, J. P.; Bastid, N.; Berger, L.; Boussange, S.; Belayev, I. M.; Blaich, T.; Buta, A.; Donà, R.; Dupieux, P.; Erö, J.; Fan, Z. G.; Fodor, Z.; Freifelder, R.; Fraysse, L.; Frolov, S.; Gobbi, A.; Grigorian, Y.; Herrmann, N.; Hildenbrand, K. D.; Jeong, S. C.; Jorio, M.; Kecskemeti, J.; Koncz, P.; Korchagin, Y.; Kotte, R.; Krämer, M.; Legrand, I.; Lebedev, A.; Manko, V.; Matulewicz, T.; Mgebrishvili, G.; Mösner, J.; Moisa, D.; Montarou, G.; Montbel, I.; Neubert, W.; Pelte, D.; Petrovici, M.; Ramillien, S.; Reisdorf, W.; Sadchikov, A.; Schüll, D.; Seres, Z.; Sikora, B.; Simion, V.; Smolyankin, S.; Sodan, U.; Teh, K. M.; Trzaska, M.; Vasiliev, M. A.; Wessels, J. P.; Wienold, T.; Wilhelmi, Z.; Wohlfarth, D.; Zhilin, A. V.

    1993-09-01

    The entropy per nucleon (S/A) has been extracted for the Au [(150-800)A MeV] + Au reaction by using the phase I setup of the 4π facility at GSI, Darmstadt. The entropy has been obtained from the comparison of various observables characterizing the dM/dZ fragment multiplicity distributions, extending up to Z~15, with those calculated with the quantum statistical model. It is the first time that S/A values are determined by considering the full ensemble of charged products detected in the reaction. Consistent values of S/A are found from different methods. These entropy values are shown to be fairly independent of the volume of the ``participant'' region considered. They are somewhat lower than those extracted in earlier works but are in good agreement with hydrodynamic calculations and suggest a low viscosity for the hot and dense nuclear matter.

  17. Single-pion production at T{sub p}=400 MeV and the excitation of the {delta} resonance

    Energy Technology Data Exchange (ETDEWEB)

    Doroshkevich, E.; Clement, H.; Ehrhardt, K.; Erhardt, A.; Wagner, G. [Physikalisches Inst., Tuebingen Univ. (Germany)

    2007-07-01

    The single-pion production in nucleon-nucleon collisions has been measured at COSY-TOF at T{sub p} = 400 MeV over the complete phase space region. In pp {yields} pp{pi}{sup 0} the {delta} excitation is heavily suppressed near threshold - though an intermediate p{delta}{sup +} configuration with the two constituents being in relative p-wave can be sensed in the angular distributions. The pp {yields} np{pi}{sup +} reaction on the other hand appears to be strongly dominated by the {delta} excitation process with n{delta}{sup ++} and p{delta}{sup +} configurations in the intermediate state, as can be observed in the Dalitzplot together with its invariant mass projections as well as in the angular distributions. (orig.)

  18. New data on cross-sections of deuteron induced nuclear reactions on gold up to 50 MeV and comparison of production routes of medically relevant Au and Hg radioisotopes

    CERN Document Server

    Tárkányi, F; Ditrói, F; Takács, S; Adam-Rebeles, R

    2016-01-01

    Investigations of cross-sections of deuteron induced nuclear reactions on gold were extended up to 50 MeV by using the standard stacked foil irradiation technique and high resolution gamma-ray spectrometry. New cross-sections are reported for the $^{197}$Au(d,xn)$^{197m,197g,195m,195g,193m,193g}$Hg and $^{197}$Au(d,x)$^{198m,198g,196m,196g,195,194}$Au nuclear reactions. The application for production of the medically relevant isotopes $^{198}$Au and $^{195m,195g,197m,197g}$Hg is discussed, including the comparison with other charged particle induced production routes. The possible use of the $^{197}$Au(d,x)$^{197m,197g,195m,193m}$Hg and $^{196m,196g}$Au reactions for monitoring deuteron beam parameters is also investigated.

  19. Target-fueled nuclear reactor for medical isotope production

    Science.gov (United States)

    Coats, Richard L.; Parma, Edward J.

    2017-06-27

    A small, low-enriched, passively safe, low-power nuclear reactor comprises a core of target and fuel pins that can be processed to produce the medical isotope .sup.99Mo and other fission product isotopes. The fuel for the reactor and the targets for the .sup.99Mo production are the same. The fuel can be low enriched uranium oxide, enriched to less than 20% .sup.235U. The reactor power level can be 1 to 2 MW. The reactor is passively safe and maintains negative reactivity coefficients. The total radionuclide inventory in the reactor core is minimized since the fuel/target pins are removed and processed after 7 to 21 days.

  20. Technical Research for Dedicated Isotope Production Reactor of South Africa

    Institute of Scientific and Technical Information of China (English)

    ZOU; Yao; LIU; Xing-min; CHEN; Hui-qiang; SUN; Zhen; WU; Yuan-yuan

    2012-01-01

    <正>Research reactor plays an important part in nuclear science and technology, application and power development. Currently, many countries in Middle East and Africa are ready to develop their own nuclear industry. South Africa sent its User Requirements Specification (URS) for a dedicated isotope production reactor to several institutes or companies, among of which Department of Reactor Engineering Research and Design (DRERD) in China Institute of Atomic Energy (CIAE) is a competitive candidate.

  1. Development of Laser Application Technology for Stable Isotope Production

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Do Young; Ko, Kwang Hoon; Kwon, Duck Hee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)] (and others)

    2007-04-15

    Tl-203 is used as a source material to produce Tl-201 radioisotope which is produced in a cyclotron by irradiating the enriched Tl-203 target. Tl-201 is a radiopharmaceutical for SPECT (single photon emission computerized tomography) to diagnose heart diseases and tumors. This Project aim to develop laser application technology to product stable isotopes such as Tl-203, Yb-168, and Yb-176. For this, photoion extraction device, atomic beam generator, dye lasers, and high power IR lasers are developed.

  2. Subsystem for control of isotope production with linear electron accelerator

    CERN Document Server

    Karasyov, S P; Uvarov, V L

    2001-01-01

    In this report the high-current LINAC subsystem for diagnostic and monitoring the basic technological parameters of isotope production (energy flux of Bremsstrahlung photons and absorbed doze in the target,target activity, temperature and consumption of water cooling the converter and target) is described.T he parallel printer port (LPT) of the personal computer is proposed to use as an interface with the measurement channels.

  3. Fission Product Yields from 232Th, 238U, and 235U Using 14 MeV Neutrons

    Science.gov (United States)

    Pierson, B. D.; Greenwood, L. R.; Flaska, M.; Pozzi, S. A.

    2017-01-01

    Neutron-induced fission yield studies using deuterium-tritium fusion-produced 14 MeV neutrons have not yet directly measured fission yields from fission products with half-lives on the order of seconds (far from the line of nuclear stability). Fundamental data of this nature are important for improving and validating the current models of the nuclear fission process. Cyclic neutron activation analysis (CNAA) was performed on three actinide targets-thorium-oxide, depleted uranium metal, and highly enriched uranium metal-at the University of Michigan's Neutron Science Laboratory (UM-NSL) using a pneumatic system and Thermo-Scientific D711 accelerator-based fusion neutron generator. This was done to measure the fission yields of short-lived fission products and to examine the differences between the delayed fission product signatures of the three actinides. The measured data were compared against previously published results for 89Kr, -90, and -92 and 138Xe, -139, and -140. The average percent deviation of the measured values from the Evaluated Nuclear Data Files VII.1 (ENDF/B-VII.1) for thorium, depleted-uranium, and highly-enriched uranium were -10.2%, 4.5%, and -12.9%, respectively. In addition to the measurements of the six known fission products, 23 new fission yield measurements from 84As to 146La are presented.

  4. Transfer products from the reactions of heavy ions with heavy nuclei. [394 to 1156 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, K.E. III

    1979-11-01

    Production of nuclides heavier than the target from /sup 86/Kr- and /sup 136/Xe-induced reactions with /sup 181/Ta and /sup 238/U was investigated. Attempts were made to produce new neutron-excess Np and Pu isotopes by the deep inelastic mechanism. No evidence was found for /sup 242/Np or /sup 247/Pu. Estimates were made for the production of /sup 242/Np, /sup 247/Pu, and /sup 248/Am from heavy-ion reactions with uranium targets. Comparisons of reactions of /sup 86/Kr and /sup 136/Xe ions with thick /sup 181/Ta targets and /sup 86/Kr, /sup 136/Xe and /sup 238/U ions with thick /sup 238/U targets indicate that the most probable products are not dependent on the projectile. The most probable products can be predicted by the equation Z - Z/sub target/ = 0.43 (A - A/sub target/) + 1.0. The major effect of the projectile is the magnitude of the production cross section of the heavy products. Based on these results, estimates are made of the most probable mass of element 114 produced from heavy-ion reactions with /sup 248/Cm and /sup 254/Es targets. These estimates give the mass number of element 114 as approx. 287 if produced in heavy-ion reactions with these very heavy targets. Excitation functions of gold and bismuth isotopes arising from /sup 86/Kr- and /sup 136/Xe-induced reactions with thin /sup 181/Ta targets were measured. These results indicate that the shape and location (in Z and A above the target) of the isotopic distributions are not strongly dependent on the projectile incident energy. Also, the nuclidic cross sections are found to increase with an increase in projectile energy to a maximum at approximately 1.4 to 1.5 times the Coulomb barrier. Above this maximum, the nuclidic cross sections are found to decrease with an increase in projectile energy. This decrease in cross section is believed to be due to fission of the heavy products caused by high excitation energy and angular momentum. 111 references, 39 figures, 34 tables.

  5. Isotope Production and Distribution Program`s Fiscal Year 1997 financial statement audit

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-27

    The Department of Energy Isotope Production and Distribution Program mission is to serve the national need for a reliable supply of isotope products and services for medicine, industry and research. The program produces and sells hundreds of stable and radioactive isotopes that are widely utilized by domestic and international customers. Isotopes are produced only where there is no U.S. private sector capability or other production capacity is insufficient to meet U.S. needs. The Department encourages private sector investment in new isotope production ventures and will sell or lease its existing facilities and inventories for commercial purposes. The Isotope Program reports to the Director of the Office of Nuclear Energy, Science and Technology. The Isotope Program operates under a revolving fund established by the Fiscal Year (FY) 1990 Energy and Water Appropriations Act and maintains financial viability by earning revenues from the sale of isotopes and services and through annual appropriations. The FY 1995 Energy and Water Appropriations Act modified predecessor acts to allow prices charged for Isotope Program products and services to be based on production costs, market value, the needs of the research community, and other factors. Although the Isotope Program functions as a business, prices set for small-volume, high-cost isotopes that are needed for research purposes may not achieve full-cost recovery. As a result, isotopes produced by the Isotope Program for research and development are priced to provide a reasonable return to the U.S. Government without discouraging their use. Commercial isotopes are sold on a cost-recovery basis. Because of its pricing structure, when selecting isotopes for production, the Isotope Program must constantly balance current isotope demand, market conditions, and societal benefits with its determination to operate at the lowest possible cost to U.S. taxpayers. Thus, this report provides a financial analysis of this situation.

  6. Isotope production and target preparation for nuclear astrophysics data

    Science.gov (United States)

    Schumann, Dorothea; Dressler, Rugard; Maugeri, Emilio Andrea; Heinitz, Stephan

    2017-09-01

    Targets are in many cases an indispensable ingredient for successful experiments aimed to produce nuclear data. With the recently observed shift to study nuclear reactions on radioactive targets, this task can become extremely challenging. Concerted actions of a certain number of laboratories able to produce isotopes and manufacture radioactive targets are urgently needed. We present here some examples of successful isotope and target production at PSI, in particular the production of 60Fe samples used for half-life measurements and neutron capture cross section experiments, the chemical processing and fabrication of lanthanide targets for capture cross section experiments at n_TOF (European Organization for Nuclear Research (CERN), Switzerland) as well as the recently performed manufacturing of highly-radioactive 7Be targets for the measurement of the 7Be(n,α)4He cross section in the energy range of interest for the Big-Bang nucleosynthesis contributing to the solving of the cosmological Li-problem. The two future projects: "Determination of the half-life and experiments on neutron capture cross sections of 53Mn" and "32Si - a new chronometer for nuclear dating" are briefly described. Moreover, we propose to work on the establishment of a dedicated network on isotope and target producing laboratories.

  7. Photofission product yields of 238U and 239Pu with 22-MeV bremsstrahlung

    Science.gov (United States)

    Wen, Xianfei; Yang, Haori

    2016-06-01

    In homeland security and nuclear safeguards applications, non-destructive techniques to identify and quantify special nuclear materials are in great demand. Although nuclear materials naturally emit characteristic radiation (e.g. neutrons, γ-rays), their intensity and energy are normally low. Furthermore, such radiation could be intentionally shielded with ease or buried in high-level background. Active interrogation techniques based on photofission have been identified as effective assay approaches to address this issue. In designing such assay systems, nuclear data, like photofission product yields, plays a crucial role. Although fission yields for neutron-induced reactions have been well studied and readily available in various nuclear databases, data on photofission product yields is rather scarce. This poses a great challenge to the application of photofission techniques. In this work, short-lived high-energy delayed γ-rays from photofission of 238U were measured in between linac pulses. In addition, a list-mode system was developed to measure relatively long-lived delayed γ-rays from photofission of 238U and 239Pu after the irradiation. Time and energy information of each γ-ray event were simultaneously recorded by this system. Cumulative photofission product yields were then determined using the measured delayed γ-ray spectra.

  8. Quantification soil production and erosion using isotopic techniques

    Science.gov (United States)

    Dosseto, Anthony; Suresh, P. O.

    2010-05-01

    Soil is a critical resource, especially in the context of a rapidly growing world's population. Thus, it is crucial to be able to quantify how soil resources evolve with time and how fast they become depleted. Over the past few years, the application of cosmogenic isotopes has permitted to constrain rates of soil denudation. By assuming constant soil thickness, it is also possible to use these denudation rates to infer soil production rates (Heimsath et al. 1997). However, in this case, it is not possible to discuss any imbalance between erosion and production, which is the core question when interested in soil resource sustainability. Recently, the measurement of uranium-series isotopes in soils has been used to quantify the residence time of soil material in the weathering profile and to infer soil production rates (Dequincey et al. 2002; Dosseto et al. 2008). Thus, the combination of U-series and cosmogenic isotopes can be used to discuss how soil resources evolve with time, whether they are depleting, increasing or in steady-state. Recent work has been undertaken in temperate southeastern Australia where a several meters thick saprolite is developed over a graniodioritc bedrock and underlains a meter or less of soil (Dosseto et al., 2008) and in tropical Puerto Rico, also in a granitic catchment. Results show that in an environment where human activity is minimal, soil and saprolite are renewed as fast as they are destroyed through denudation. Further work is investigating these processes at other sites in southeastern Australia (Frogs Hollow; Heimsath et al. 2001) and Puerto Rico (Rio Mameyes catchment; andesitic bedrock). Results will be presented and a review of the quantification of the rates of soil evolution using isotopic techniques will be given. Dequincey, O., F. Chabaux, et al. (2002). Chemical mobilizations in laterites: Evidence from trace elements and 238U-234U-230Th disequilibria. Geochim. Cosmochim. Acta 66(7): 1197-1210. Dosseto, A., S. P

  9. Soft Fusion Energy Path: Isotope Production in Energy Subcritical/Economy Hypercritical D +D Colliding-Beam Mini Fusion Reactor `Exyder'

    Science.gov (United States)

    Hester, Tim; Maglich, Bogdan; Calsec Collaboration

    2015-03-01

    Bethe1 and Sakharov2 argued for soft fusion energy path via isotope production, substantiated by Manheimer3. - Copious T and 3He production4 , 5 from D(d, p) T and D(d, n) 3He reactions in 725 KeV D +D colliding beams was measured in weak-focusing Self-Collider6 , 7 radius 0.15 m, in B = 3.12 T, non-linearly stabilized by electron cloud oscillations8 to confinement time = 24 s. Simulations6 predict that by switching to strong focusing9, 10 deuterons 0.75 MeV each, generate 1 3He +1T +1p + 1n at total input energy cost 10.72 MeV. Economic value of T and 3He is 65 and 120 MeV/atom, respectively. We obtain economic gain 205MeV/10.72 MeV ~ 2,000% i.e. 3He production funds cost of T. If first wall is made of Thorium n's will breed 233U releasing 200 MeV/fission, at neutron cost 5.36 MeV versus 160 MeV in beam on target, resulting in no cost 3He production, valued 75K/g. 1. Physics Today, May 1979, p.44; 2. Memoirs, Vintage Books, (1992); 3. Phys. Today, May 2012 p. 12; 4. Phys. Rev. Lett. 54, 796 (1985); 5. Bull. APS, 57, No. 3 (2012); 6. Part. Acc.1, (1970); 7. ANEUTRONIC FUSION NIM A 271 1-167 (1988); 8. Phys. Rev. Lett. 70, 1818 (1993); 9. Part. Acc. 34, 13 (1990).

  10. Production of heavy element and search for new isotopes at JAERI-RMS

    Energy Technology Data Exchange (ETDEWEB)

    Ikuta, Tomohiko [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-07-01

    The new neutron deficient isotope {sup 209}Th and {sup 212}Pa have been produced in heavy ion induced fusion evaporation reactions. The evaporation residues were separated in-flight by the JAERI recoil mass separator (JAERI-RMS). The {alpha}-decay energy of {sup 209}Th and {sup 212}Pa are 8.080(50) MeV and 8.270(30) MeV, respectively. The corresponding half-lives are 3.8{sub -1.5}{sup +6.9} ms and 5.1{sub -1.9}{sup +6.1} ms. (author)

  11. Production of Medical isotope Technecium-99 from DT Fusion neutrons

    Science.gov (United States)

    Boguski, John; Gentile, Charles; Ascione, George

    2011-10-01

    High energy neutrons produced in DT fusion reactors have a secondary application for use in the synthesis of valuable man-made isotopes utilized in industry today. One such isotope is metastable Technecium-99 (Tc99m), a low energy gamma emitter used in ~ 85% of all medical imaging diagnostics. Tc99m is created through beta decay of Molybdenum-99 (Mo99), which itself has only a 66 hour half-life and must be created from a neutron capture by the widely available and stable isotope Molydenum-98. Current worldwide production of Tc99m occurs in just five locations and relies on obtaining the fission byproduct Mo99 from highly enriched Uranium reactors. A Tc99m generator using DT fusion neutrons, however, could potentially be operated at individual hospitals and medical facilities without the use of any fissile material. The neutron interaction of the DT neutrons with Molybdenum in a potential device geometry was modeled using Monte Carlo neutron transport code MCNP. Trial experiments were also performed to test the viability of using DT neutrons to create ample quantities of Tc99m. Modeling and test results will follow.

  12. Entropy production in the Au+Au reaction between 150[ital A] and 800[ital A] MeV

    Energy Technology Data Exchange (ETDEWEB)

    Kuhn, C.; Konopka, J.; Coffin, J.P.; Cerruti, C.; Fintz, P.; Guillaume, G.; Houari, A.; Jundt, F.; Maguire, C.F.; Rami, F.; Tezkratt, R.; Wagner, P.; Basrak, Z.; Caplar, R.; Cindro, N.; Hoelbling, S.; Alard, J.P.; Bastid, N.; Berger, L.; Boussange, S.; Belayev, I.M.; Blaich, T.; Buta, A.; Dona, R.; Dupieux, P.; Eroe, J.; Fan, Z.G.; Fodor, Z.; Freifelder, R.; Fraysse, L.; Frolov, S.; Gobbi, A.; Grigorian, Y.; Herrmann, N.; Hildenbrand, K.D.; Jeong, S.C.; Jorio, M.; Kecskemeti, J.; Koncz, P.; Korchagin, Y.; Kotte, R.; Kraemer, M.; Legrand, I.; Lebedev, A.; Manko, V.; Matulewicz, T.; Mgebrishvili, G.; Moesner, J.; Moisa, D.; Montarou, G.; Montbel, I.; Neubert, W.; Pelte, D.; Petrovici, M.; Ramillien, S.; Reisdorf, W.; Sadchikov, A.; Schuell, D.; Seres, Z.; Sikora, B.; Simion, V.; Smolyankin, S.; Sodan, U.; Teh, K.M.; Trzaska, M.; Vasiliev, M.A.; Wessels, J.P.; Wienold, T.; Wilhelmi, Z.; Wohlfarth, D.; Zhilin, A.V. (Institute for Physics and Nuclear Engineering, Bucharest (Romania) Centra

    1993-09-01

    The entropy per nucleon ([ital S]/[ital A]) has been extracted for the Au [(150--800)[ital A] MeV] + Au reaction by using the phase I setup of the 4[pi] facility at GSI, Darmstadt. The entropy has been obtained from the comparison of various observables characterizing the [ital dM]/[ital dZ] fragment multiplicity distributions, extending up to [ital Z][similar to]15, with those calculated with the quantum statistical model. It is the first time that [ital S]/[ital A] values are determined by considering the full ensemble of charged products detected in the reaction. Consistent values of [ital S]/[ital A] are found from different methods. These entropy values are shown to be fairly independent of the volume of the participant'' region considered. They are somewhat lower than those extracted in earlier works but are in good agreement with hydrodynamic calculations and suggest a low viscosity for the hot and dense nuclear matter.

  13. New neutron-rich isotope production in 154Sm+160Gd

    Directory of Open Access Journals (Sweden)

    Ning Wang

    2016-09-01

    Full Text Available Deep inelastic scattering in 154Sm+160Gd at energies above the Bass barrier is for the first time investigated with two different microscopic dynamics approaches: improved quantum molecular dynamics (ImQMD model and time dependent Hartree–Fock (TDHF theory. No fusion is observed from both models. The capture pocket disappears for this reaction due to strong Coulomb repulsion and the contact time of the di-nuclear system formed in head-on collisions is about 700 fm/c at an incident energy of 440 MeV. The isotope distribution of fragments in the deep inelastic scattering process is predicted with the simulations of the latest ImQMD-v2.2 model together with a statistical code (GEMINI for describing the secondary decay of fragments. More than 40 extremely neutron-rich unmeasured nuclei with 58≤Z≤76 are observed and the production cross sections are at the order of μb to mb. The multi-nucleon transfer reaction of Sm+Gd could be an alternative way to synthesize new neutron-rich lanthanides which are difficult to be produced with traditional fusion reactions or fission of actinides.

  14. New neutron-rich isotope production in 154Sm+160Gd

    Science.gov (United States)

    Wang, Ning; Guo, Lu

    2016-09-01

    Deep inelastic scattering in 154Sm+160Gd at energies above the Bass barrier is for the first time investigated with two different microscopic dynamics approaches: improved quantum molecular dynamics (ImQMD) model and time dependent Hartree-Fock (TDHF) theory. No fusion is observed from both models. The capture pocket disappears for this reaction due to strong Coulomb repulsion and the contact time of the di-nuclear system formed in head-on collisions is about 700 fm/c at an incident energy of 440 MeV. The isotope distribution of fragments in the deep inelastic scattering process is predicted with the simulations of the latest ImQMD-v2.2 model together with a statistical code (GEMINI) for describing the secondary decay of fragments. More than 40 extremely neutron-rich unmeasured nuclei with 58 ≤ Z ≤ 76 are observed and the production cross sections are at the order of μb to mb. The multi-nucleon transfer reaction of Sm+Gd could be an alternative way to synthesize new neutron-rich lanthanides which are difficult to be produced with traditional fusion reactions or fission of actinides.

  15. New neutron-rich isotope production in $^{154}$Sm+$^{160}$Gd

    CERN Document Server

    Wang, Ning

    2016-01-01

    Deep inelastic scattering in $^{154}$Sm+$^{160}$Gd at energies above the Bass barrier is for the first time investigated with two different microscopic dynamics approaches: improved quantum molecular dynamics (ImQMD) model and time dependent Hartree-Fock (TDHF) theory. No fusion is observed from both models. The capture pocket disappears for this reaction due to strong Coulomb repulsion and the contact time of the di-nuclear system formed in head-on collisions is about 700 fm/c at an incident energy of 440 MeV. The isotope distribution of fragments in the deep inelastic scattering process is predicted with the simulations of the latest ImQMD-v2.2 model together with a statistical code (GEMINI) for describing the secondary decay of fragments. More than 40 extremely neutron-rich unmeasured nuclei with $58 \\le Z\\le 76$ are observed and the production cross sections are at the order of ${\\rm \\mu b}$ to mb. The multi-nucleon transfer reaction of Sm+Gd could be an alternative way to synthesize new neutron-rich lant...

  16. Method for production of an isotopically enriched compound

    Science.gov (United States)

    Watrous, Matthew G.

    2012-12-11

    A method is presented for producing and isolating an isotopically enriched compound of a desired isotope from a parent radionuclide. The method includes forming, or placing, a precipitate containing a parent radionuclide of the desired daughter isotope in a first reaction zone and allowing sufficient time for the parent to decay into the desired gaseous daughter radioisotope. The method further contemplates collecting the desired daughter isotope as a solid in a second reaction zone through the application of temperatures below the freezing point of the desired isotope to a second reaction zone that is connected to the first reaction zone. Specifically, a method is presented for producing isotopically enriched compounds of xenon, including the radioactive isotope Xe-131m and the stable isotope Xe-131.

  17. Construction Status of the Beamline for Radio-Isotope Production in the Korea Multi-purpose Accelerator Complex

    Energy Technology Data Exchange (ETDEWEB)

    Chung, B. H.; Yoon, S. P.; Seol, K. T.; Kim, H. S.; Kwon, H. J.; Cho, Y. S. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    The 100-MeV beamline consist of 5 target room, a TR 103 as one of these is operating beamline, and a TR 101 as the other beamline is under construction as shown in Fig. 1. The TR 101 as beamline target room will be used for the high value-added medical isotope production and increased utilization of the proton accelerator. The optical system of the beamline consisted of dipole and quadrupole, and it included beam position monitor (BPM) and current transformer (CT) for beam diagnostics. The beamline was inserted into the carbon block and the aluminum collimator, the end of pipe as beam window was used for the aluminum to reduce the radioactive of materials. The target transfer equipment is being installed for RI production. The RI Beamline was aligned using the laser tracker, and vacuum leak was not detected by the helium leak detector. This facility is expected to the high value-added medical isotope production and increased utilization of the proton accelerator.

  18. Tracking Eukaryotic Production and Burial Through Time with Zinc Isotopes

    Science.gov (United States)

    Tang, T. Y. S.; Planavsky, N.; Owens, J. D.; Love, G. D.; Lyons, T.; Peterson, L. C.; Knoll, A. H.; Dupont, C. L.; Reinhard, C.; Zumberge, A.

    2015-12-01

    Zinc is an important, often co-limiting nutrient for eukaryotes in the oceans today. Given the importance of Zn in the modern oceans, we developed a Zn isotope approach to track the extent of Zn limitation and eukaryotic production through Earth's history. Specifically, we use the isotopic systematics of the pyrite (δ66Znpyr), rock extracts (bitumen) and kerogen pyrolysate (δ66Znorg) within euxinic black shales. We show that δ66Znpyr of euxinic core-top muds from the Cariaco basin capture the global deep seawater signature, validating its use as a seawater proxy. Additionally, we propose that Δ66Znpyr-org can be used to track surface water zinc bioavailability. Detailed studies of short-lived oceanic anoxic events such as Cretaceous OAE2, which punctuate an otherwise dominantly oxic Phanerozoic world, exhibit dramatic shifts in seawater δ66Zn and organic bound zinc. Such perturbations are consistent with the demise of eukaryotes under a nitrogen stressed regime, in which cyanobacteria carry the competitive advantage. Contradictory to previous models, however, our data suggest that zinc remained largely bioavailable throughout these anoxic intervals despite significant drawdown of the global reservoir. The framework developed from studies of the modern, Cenozoic, and Mesozoic can be used to track the Precambrian evolution of the marine Zn cycle and the rise of eukaryotic algae to ecological dominance.

  19. 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)

  20. Study of the production of neutron-rich isotope beams issuing from fissions induced by fast neutrons; Etude de la production de faisceaux riches en neutrons par fission induite par neutrons rapides

    Energy Technology Data Exchange (ETDEWEB)

    Lau, Ch

    2000-09-15

    This work is a contribution to the PARRNe project (production of radioactive neutron-rich isotopes). This project is based on the fission fragments coming from the fission of 238-uranium induced by fast neutrons. The fast neutron flux is produced by the collisions of deutons in a converter. Thick targets of uranium carbide and liquid uranium targets have been designed in order to allow a quick release of fission fragments. A device, able to trap on a cryogenic thimble rare gas released by the target, has allowed the production of radioactive nuclei whose half-life is about 1 second. This installation has been settled to different deuton accelerators in the framework of the European collaboration SPIRAL-2. A calibration experiment has proved the feasibility of fixing an ISOL-type isotope separator to a 15 MV tandem accelerator, this installation can provide 500 nA deutons beams whose energy is 26 MeV and be a valuable tool for studying fast-neutron induced fission. Zinc, krypton, rubidium, cadmium, iodine, xenon and cesium beams have been produced in this installation. The most intense beams reach 10000 nuclei by micro-coulomb for 26 MeV deutons. An extra gain of 2 magnitude orders can be obtained by using a more specific ion source and by increasing the thickness of the target. Another extra gain of 2 magnitude orders involves 100 MeV deutons.

  1. Production rate of proton-induced isotopes in different materials

    Energy Technology Data Exchange (ETDEWEB)

    Porras, E. E-mail: ester@pollux.matapl.uv.es; Sanchez, F.; Reglero, V.; Cordier, B.; Dean, A.J.; Lei, F.; Perez, J.M.; Swinyard, B.M

    2000-01-01

    High background counting rates are the main limitation on sensitivity of satellite borne gamma-ray instrumentations. The observed background comes from different sources: cosmic diffuse, charged particles and high energetic photons. Among the different background components, that due to the activation of the telescope and satellite passive materials by cosmic protons is the most difficult component to evaluate. In the framework of background studies and sensitivity estimations for the INTEGRAL and MINISAT-01 projects, a wide range of materials has been irradiated with proton beams at different energies to identify the induced unstable isotopes and their production cross-sections. In this paper we present experimental results obtained from the analysis of such irradiation experiments. These values are compared to those obtained by means of the two frequently used prediction methods: GEANT/GCALOR Monte-Carlo code and Silberberg and Tsao semiempirical expressions.

  2. Cross sections from 800 MeV proton irradiation of terbium

    Energy Technology Data Exchange (ETDEWEB)

    Engle, J.W., E-mail: jwengle@lanl.gov [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Mashnik, S.G.; Bach, H.; Couture, A.; Jackman, K.; Gritzo, R.; Ballard, B.D.; Fassbender, M.; Smith, D.M.; Bitteker, L.J.; Ullmann, J.L.; Gulley, M.S.; Pillai, C.; John, K.D.; Birnbaum, E.R. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Nortier, F.M., E-mail: meiring@lanl.gov [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2012-11-02

    Terbium foils were irradiated with 800 MeV protons to ascertain the potential for production of lanthanide isotopes of interest in medical, astrophysical, and basic science research and to contribute to nuclear data repositories. Isotopes produced in the foil were quantified by gamma spectroscopy. Cross sections for 35 isotopes produced in the irradiation are reported and compared with predictions by the MCNP6 transport code using the CEM03.03, Bertini and INCL + ABLA event generators. Our results indicate the need to accurately consider fission and fragmentation of relatively light target nuclei like terbium in the modeling of nuclear reactions at 800 MeV. The predictive power of the code was found to be different for each event generator tested but was satisfactory for most of the product yields in the mass region where spallation reactions dominate. However, none of the event generators' results are in complete agreement with measured data.

  3. Cross Sections from 800 MeV Proton Irradiation of Terbium

    CERN Document Server

    Engle, J W; Bach, H; Couture, A; Jackman, K; Gritzo, R; Ballard, B D; Faßbender, M; Smith, D M; Bitteker, L J; Ullmann, J L; Gulley, M; Pillai, C; John, K D; Birnbaum, E R; Nortier, F M

    2012-01-01

    A single terbium foil was irradiated with 800 MeV protons to ascertain the potential for production of lanthanide isotopes of interest in medical, astrophysical, and basic science research and to contribute to nuclear data repositories. Isotopes produced in the foil were quantified by gamma spectroscopy. Cross sections for 36 isotopes produced in the irradiation are reported and compared with predictions by the MCNP6 transport code using the CEM03.03, Bertini, and INCL+ABLA event generators. Our results indicate the need to accurately consider fission and fragmentation of relatively light target nuclei like terbium in the modeling of nuclear reactions at 800 MeV. The predictive power of the code was found to be different for each event generator tested but was satisfactory for most of the product yields in the mass region where spallation reactions dominate. However, none of the event generators' results are in complete agreement with measured data.

  4. Exploratory study of fission product yields of neutron-induced fission of 235U , 238U , and 239Pu at 8.9 MeV

    Science.gov (United States)

    Bhatia, C.; Fallin, B. F.; Gooden, M. E.; Howell, C. R.; Kelley, J. H.; Tornow, W.; Arnold, C. W.; Bond, E.; Bredeweg, T. A.; Fowler, M. M.; Moody, W.; Rundberg, R. S.; Rusev, G. Y.; Vieira, D. J.; Wilhelmy, J. B.; Becker, J. A.; Macri, R.; Ryan, C.; Sheets, S. A.; Stoyer, M. A.; Tonchev, A. P.

    2015-06-01

    Using dual-fission chambers each loaded with a thick (200 -400 -mg /c m2) actinide target of 235 ,238U or 239Pu and two thin (˜10 -100 -μ g /c m2) reference foils of the same actinide, the cumulative yields of fission products ranging from 92Sr to 147Nd have been measured at En= 8.9 MeV . The 2H(d ,n ) 3He reaction provided the quasimonoenergetic neutron beam. The experimental setup and methods used to determine the fission product yield (FPY) are described, and results for typically eight high-yield fission products are presented. Our FPYs for 235U(n ,f ) , 238U(n ,f ) , and 239Pu(n ,f ) at 8.9 MeV are compared with the existing data below 8 MeV from Glendenin et al. [Phys. Rev. C 24, 2600 (1981), 10.1103/PhysRevC.24.2600], Nagy et al. [Phys. Rev. C 17, 163 (1978), 10.1103/PhysRevC.17.163], Gindler et al. [Phys. Rev. C 27, 2058 (1983), 10.1103/PhysRevC.27.2058], and those of Mac Innes et al. [Nucl. Data Sheets 112, 3135 (2011), 10.1016/j.nds.2011.11.009] and Laurec et al. [Nucl. Data Sheets 111, 2965 (2010), 10.1016/j.nds.2010.11.004] at 14.5 and 14.7 MeV, respectively. This comparison indicates a negative slope for the energy dependence of most fission product yields obtained from 235U and 239Pu , whereas for 238U the slope issue remains unsettled.

  5. Carbon Isotope Measurements of Experimentally-Derived Hydrothermal Mineral-Catalyzed Organic Products by Pyrolysis-Isotope Ratio Mass Spectrometry

    Science.gov (United States)

    Socki, Richard A.; Fu, Qi; Niles, Paul B.

    2011-01-01

    We report results of experiments to measure the C isotope composition of mineral catalyzed organic compounds derived from high temperature and high pressure synthesis. These experiments make use of an innovative pyrolysis technique designed to extract and measure C isotopes. To date, our experiments have focused on the pyrolysis and C isotope ratio measurements of low-molecular weight intermediary hydrocarbons (organic acids and alcohols) and serve as a proof of concept for making C and H isotope measurements on more complicated mixtures of solid-phase hydrocarbons and intermediary products produced during high temperature and high pressure synthesis on mineral-catalyzed surfaces. The impetus for this work stems from recently reported observations of methane detected within the Martian atmosphere [1-4], coupled with evidence showing extensive water-rock interaction during Martian history [5-7]. Methane production on Mars could be the result of synthesis by mineral surface-catalyzed reduction of CO2 and/or CO by Fischer-Tropsch Type (FTT) reactions during serpentization reactions [8,9]. Others have conducted experimental studies to show that FTT reactions are plausible mechanisms for low-molecular weight hydrocarbon formation in hydrothermal systems at mid-ocean ridges [10-12]. Further, recent experiments by Fu et al. [13] focus on examining detailed C isotope measurements of hydrocarbons produced by surface-catalyzed mineral reactions. Work described in this paper details the experimental techniques used to measure intermediary organic reaction products (alcohols and organic acids).

  6. Estimate of the radiation source term for 18F production via thick H218O targets bombarded with 18 MeV protons

    Science.gov (United States)

    Cruzate, Juan Ángel

    2015-12-01

    The positron-emitting radionuclide most important from the point of view of radiation protection is 18F. This isotope is usually produced by bombarding 18O-enriched water with protons. Currently there are few experimental data on the radiation source term generated during these reactions. In addition, presently there is no theoretical estimates of this source term, for use in radiation protection, validated by experimental data. Up till now this term is calculated by using nuclear interactions' simulation codes, such as ALICE91. An estimate of the energy spectra for neutrons and photons, induced by 18 MeV protons on H218O target, have been calculated by using MCNPX code with cross sections from release 0 of ENDF/B VII library for all materials except 18O, for which TENDL-2012 library was used. This estimate was validated against a recent experiment carried out at the Japan Atomic Energy Agency (JAEA). The calculated spectra have generally well reproduced experiments. The results show that the calculated radiation source term may be used to estimate the neutron activation of the accelerator components and the cyclotron building, to calculate the cyclotron shielding, and to carry out radiation protection evaluations in general, for the case of cyclotrons producing 18F by means of the 18O(p,n)18F nuclear reactions, for proton energies up to 18 MeV.

  7. First measurement of radioactive isotope production through cosmic-ray muon spallation in Super-Kamiokande IV

    CERN Document Server

    ,

    2016-01-01

    Cosmic-ray-muon spallation-induced radioactive isotopes with $\\beta$ decays are one of the major backgrounds for solar, reactor, and supernova relic neutrino experiments. Unlike in scintillator, production yields for cosmogenic backgrounds in water have not been exclusively measured before, yet they are becoming more and more important in next generation neutrino experiments designed to search for rare signals. We have analyzed the low-energy trigger data collected at Super-Kamiokande-IV in order to determine the production rates of $^{12}$B, $^{12}$N, $^{16}$N, $^{11}$Be, $^9$Li, $^8$He, $^9$C, $^8$Li, $^8$B and $^{15}$C. These rates were extracted from fits to time differences between parent muons and subsequent daughter $\\beta$'s by fixing the known isotope lifetimes. Since $^9$Li can fake an inverse-beta-decay reaction chain via a $\\beta + n$ cascade decay, producing an irreducible background with detected energy up to a dozen MeV, a dedicated study is needed for evaluating its impact on future measuremen...

  8. Stable isotope-labeled excipients for drug product identification and counterfeit detection.

    Science.gov (United States)

    Felton, Linda A; Shah, Punit P; Sharp, Zachary; Atudorei, Viorel; Timmins, Graham S

    2011-01-01

    Counterfeit drug products have become a major problem worldwide and a number of techniques to detect counterfeit products or reduce the potential for counterfeiting have been investigated. This study examined the use of stable isotope-labeled excipients in solid dosage forms as a method to identify drug products and to detect counterfeits. (2)H- and (13)C-glucose were used as model excipients and incorporated in wet granulated formulations at a variety of different isotopic ratios. The ratios of (2)H/(1)H and (13)C/(12)C in each product were then determined by isotope ratio mass spectrometry. Results demonstrated the ability to detect the isotope-labeled glucose in both granules and tablets. It was possible to use the isotope ratios to differentiate between specific batches of granules, demonstrating the potential of this technique for in-product, batch-specific identification.

  9. Gamma ray production cross sections in proton induced reactions on natural Mg, Si and Fe targets over the proton energy range 30 up to 66 MeV

    CERN Document Server

    Yahia-Chérif, W; Kiener, J; Tatischeff, V; Lawrie, E; Lawrie, J J; Belhout, A; Benhabiles, H; Bucher, T D; Chafa, A; Damache, S; Debabi, M; Deloncle, I; Easton, J L; Hamadache, C; Hammache, F; Jones, P; Kheswa, B V; Khumalo, N; Lamula, T; Majola, S T H; Negi, D; Ndayishimye, J; Noncolela, S P; Moussa, D; Nchodu, R; Papka, P; de Sereville, N; Sharpey-Schafer, J F; Shirinda, O; Wiedeking, M; Wyngaardt, S

    2015-01-01

    Gamma-ray excitation functions have been measured for 30, 42, 54 and 66 MeV proton beams accelerated onto C + O (Mylar), Mg, Si, and Fe targets of astrophysical interest at the separate-sector cyclotron of iThemba LABS in Somerset West (Cape Town, South Africa). A large solid angle, high energy resolution detection system of the Eurogam type was used to record Gamma-ray energy spectra. Derived preliminary results of Gamma-ray line production cross sections for the Mg, Si and Fe target nuclei are reported and discussed. The current cross section data for known, intense Gamma-ray lines from these nuclei consistently extend to higher proton energies previous experimental data measured up to Ep ~ 25 MeV at the Orsay and Washington tandem accelerators. Data for new Gamma-ray lines observed for the first time in this work are also reported.

  10. Isotopically Modified Molybdenum: Production for Application in Nuclear Energy

    Science.gov (United States)

    Smirnov, A. Yu.; Bonarev, A. K.; Sulaberidze, G. A.; Borisevich, V. D.; Kulikov, G. G.; Shmelev, A. N.

    The possibility to use the isotopically modified molybdenum as a constructive material for the fuel rods of light water and fast reactors is discussed. The calculations demonstrate that the isotopically modified molybdenum with an average neutron absorption cross-section comparable to that of zirconium can be obtained with the reasonable for practice cost by a cascade of gas centrifuges, specially designed for separation of non-uranium isotopes.

  11. Stable isotope separation; Separations physicochimiques d'isotopes stables realisations et etudes de petites productions

    Energy Technology Data Exchange (ETDEWEB)

    Botter, F.; Molinari, Ph.; Dirian, G. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    which cooling water circulates. Studies are going forward to increase the separation factor of the cascade by using an auxiliary gas. Isotopic Exchange: A series of experiments has been performed to determine the isotopic separation factor between a lithium amalgam and an organic solvent containing a lithium salt. The various parameters which may enter into this exchange were studied: the influence of the type of solvent (the two solvents used were dimethylformamide and tetrahydrofurane), of the temperature, of the concentration and of the nature of the associated halogen. Solutions of Li metal and liquid NH{sub 3} were studied also. A number of tests were carried out to see whether there was a difference between the isotopic compositions of the Li present in the two liquid layers obtained by the dissolution of Li metal in ammonia. No difference was observed between the Li isotopic ratios in the two phases. This was also true in the case of a layer of of Li in liquid NH{sub 3} and a layer of Li I in a similar solvent. Electromigration: The method of counter current electro Migration in fused salts is a powerful isotopic enrichment technique. It can be used successfully to separate the isotopes of elements with strongly metallic character. In the case of alkalis, small quantities of isotopically pure {sup 7}Li have been obtained, while the enrichment factors obtained for potassium are of the order of 10. With regard to the alkaline earths, it has been possible to produce small quantities of calcium enriched 5 times in {sup 46}Ca. However considerable technological difficulties rise up in the way of production on a semi-industrial scale. (authors) [French] Nous avons effectue Ia separation de deuterium pur, a partir de melanges gazeux d'hydrogene et de deuterium, par chromatographie de deplacement de bande sur colonnes de palladium supporte. Les meilleures performances ont ete obtenues par des colonnes de Pd sur fritte d'alumine {alpha}. Avec une colonne de ce

  12. Production of the cosmogenic isotopes 3H, 7Be, 10Be, and 36Cl in the Earth's atmosphere by solar and galactic cosmic rays

    Science.gov (United States)

    Webber, W. R.; Higbie, P. R.; McCracken, K. G.

    2007-10-01

    In a follow-up study to the earlier work of Webber and Higbie (2003) on 10Be production in the Earth's atmosphere by cosmic rays, we have calculated the atmospheric production of the cosmogenic isotopes 3H, 7Be, 10Be, and 36Cl using the FLUKA Monte Carlo code. This new calculation of atmospheric yields of these isotopes is based on 107 vertically incident protons at each of 24 logarithmically spaced energies from 10 MeV to 10 GeV, 102 times the number used in the earlier calculation, along with the latest cross sections. This permits a study of the production due to solar cosmic rays as well as galactic cosmic rays at lower energies where isotope production is a very sensitive function of energy. Solar cosmic ray spectra are reevaluated for all of the major events occurring since 1956. In terms of yearly production of 10Be, only the February 1956 solar event makes a major contribution. For 36Cl these yearly SCR production contributions are 2-5 times larger depending on the solar cosmic ray energy spectra. We have determined the yearly production of 10Be, 36Cl, and other cosmogenic isotopes above 65° geomagnetic latitude for the time period 1940-2006 covering six solar 11-year (a) cycles. The average peak-to-peak 11-a amplitude of this yearly production is 1.77. The effects of latitudinal mixing alter these direct polar production values considerably, giving an average peak-to-peak 11-a amplitude of 1.48 for the global average production.

  13. Isotope production and distribution Programs Fiscal Year (FY) 1995 Financial Statement Audit (ER-FC-96-01)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-02-12

    The charter of the Department of Energy (DOE) Isotope Production and Distribution Program (Isotope Program) covers the production and sale of radioactive and stable isotopes, associated byproducts, surplus materials such as lithium and deuterium, and related isotope services. Services provided include, but are not limited to, irradiation services, target preparation and processing, source encapsulation and other special preparations, analyses, chemical separations, and leasing of stable isotopes for research purposes. Isotope Program products and services are sold worldwide for use in a wide variety of research, development, biomedical, and industrial applications. The Isotope Program reports to the Director of the Office of Nuclear Energy, Science and Technology. The Isotope Program operates under a revolving fund, as established by the Fiscal Year 1990 Energy and Water Appropriations Act (Public Law 101-101). The Fiscal Year 1995 Appropriations Act (Public Law 103-316) modified predecessor acts to allow prices charged for Isotope Program products and services to be based on production costs, market value, the needs of the research community, and other factors. Prices set for small-volume, high-cost isotopes that are needed for research may not achieve full-cost recovery. Isotope Program costs are financed by revenues from the sale of isotopes and associated services and through payments from the isotope support decision unit, which was established in the DOE fiscal year 1995 Energy, Supply, Research, and Development appropriation. The isotope decision unit finances the production and processing of unprofitable isotopes that are vital to the national interest.

  14. Stable isotope separation in calutrons: Forty years of production and distribution

    Energy Technology Data Exchange (ETDEWEB)

    Bell, W.A.; Tracy, J.G.

    1987-11-01

    The stable isotope separation program, established in 1945, has operated continually to provide enriched stable isotopes and selected radioactive isotopes, including the actinides, for use in research, medicine, and industrial applications. This report summarizes the first forty years of effort in the production and distribution of stable isotopes. Evolution of the program along with the research and development, chemical processing, and production efforts are highlighted. A total of 3.86 million separator hours has been utilized to separate 235 isotopes of 56 elements. Relative effort expended toward processing each of these elements is shown. Collection rates (mg/separator h), which vary by a factor of 20,000 from the highest to the lowest (/sup 205/Tl to /sup 46/Ca), and the attainable isotopic purity for each isotope are presented. Policies related to isotope pricing, isotope distribution, and support for the enrichment program are discussed. Changes in government funding, coupled with large variations in sales revenue, have resulted in 7-fold perturbations in production levels.

  15. Computational investigation of 99Mo, 89Sr, and 131I production rates in a subcritical UO2(NO32 aqueous solution reactor driven by a 30-MeV proton accelerator

    Directory of Open Access Journals (Sweden)

    Z. Gholamzadeh

    2015-12-01

    Full Text Available The use of subcritical aqueous homogenous reactors driven by accelerators presents an attractive alternative for producing 99Mo. In this method, the medical isotope production system itself is used to extract 99Mo or other radioisotopes so that there is no need to irradiate common targets. In addition, it can operate at much lower power compared to a traditional reactor to produce the same amount of 99Mo by irradiating targets. In this study, the neutronic performance and 99Mo, 89Sr, and 131I production capacity of a subcritical aqueous homogenous reactor fueled with low-enriched uranyl nitrate was evaluated using the MCNPX code. A proton accelerator with a maximum 30-MeV accelerating power was used to run the subcritical core. The computational results indicate a good potential for the modeled system to produce the radioisotopes under completely safe conditions because of the high negative reactivity coefficients of the modeled core. The results show that application of an optimized beam window material can increase the fission power of the aqueous nitrate fuel up to 80%. This accelerator-based procedure using low enriched uranium nitrate fuel to produce radioisotopes presents a potentially competitive alternative in comparison with the reactor-based or other accelerator-based methods. This system produces ∼1,500 Ci/wk (∼325 6-day Ci of 99Mo at the end of a cycle.

  16. Feasibility study of medical isotope production at Sandia National Laboratories

    Energy Technology Data Exchange (ETDEWEB)

    Massey, C.D.; Miller, D.L.; Carson, S.D. [Sandia National Labs., Albuquerque, NM (United States). Environmental Regulatory Assessment Dept.] [and others

    1995-12-01

    In late 1994, Sandia National Laboratories in Albuquerque, New Mexico, (SNL/NM), was instructed by the Department of Energy (DOE) Isotope Production and Distribution Program (IPDP) to examine the feasibility of producing medically useful radioisotopes using the Annular Core Research Reactor (ACRR) and the Hot Cell Facility (HCF). Los Alamos National Laboratory (LANL) would be expected to supply the targets to be irradiated in the ACRR. The intent of DOE would be to provide a capability to satisfy the North American health care system demand for {sup 99}Mo, the parent of {sup 99m}Tc, in the event of an interruption in the current Canadian supply. {sup 99m}Tc is used in 70 to 80% of all nuclear medicine procedures in the US. The goal of the SNL/NM study effort is to determine the physical plant capability, infrastructure, and staffing necessary to meet the North American need for {sup 99}Mo and to identify and examine all issues with potential for environmental impact.

  17. Towards tabletop production of intense quasimonochromatic X-ray beams using small 2-20 MeV accelerators

    Science.gov (United States)

    Avakian, Robert O.; Ispirian, Karo A.

    2005-08-01

    The existing synchrotron radiation sources and the fourth generation x-ray sources, which are projected at SLAC, USA, and DESY, Germany, are very expensive. For this reason the search for the novel and cheaper sources using various types of radiation produced by 2-20 MeV electrons available at many hospitals, universities and firms in various countries is of great interest. A review of the physics, history, new theoretical and experimental results and of some applications is given with a purpose to consider the possibilities of construction of small tabletop sources of quasimonochromatic X-ray photon beams necessary for scientific, industrial, medicine and other applications.

  18. Light-ion production from O, Si, Fe and Bi induced by 175 MeV quasi-monoenergetic neutron

    CERN Document Server

    Bevilacqua, R; Jansson, K; Gustavsson, C; Osterlund, M; Simutkin, V; Hayashi, M; Hirayama, S; Naitou, Y; Watanabe, Y; Hjalmarsson, A; Prokofiev, A; Tippawan, U; Lecolley, F -R; Marie, N; Leray, S; David, J -C; Mashnik, S

    2013-01-01

    We have measured double-differential cross sections in the interaction of 175 MeV quasimonoenergetic neutrons with O, Si, Fe and Bi. We have compared these results with model calculations with INCL4.5-Abla07, MCNP6 and TALYS-1.2. We have also compared our data with PHITS calculations, where the pre-equilibrium stage of the reaction was accounted respectively using the JENDL/HE-2007 evaluated data library, the quantum molecular dynamics model (QMD) and a modified version of QMD (MQMD) to include a surface coalescence model. The most crucial aspect is the formation and emission of composite particles in the pre-equilibrium stage.

  19. CR-39 track detector calibration for H, He, and C ions from 0.1-0.5 MeV up to 5 MeV for laser-induced nuclear fusion product identification.

    Science.gov (United States)

    Baccou, C; Yahia, V; Depierreux, S; Neuville, C; Goyon, C; Consoli, F; De Angelis, R; Ducret, J E; Boutoux, G; Rafelski, J; Labaune, C

    2015-08-01

    Laser-accelerated ion beams can be used in many applications and, especially, to initiate nuclear reactions out of thermal equilibrium. We have experimentally studied aneutronic fusion reactions induced by protons accelerated by the Target Normal Sheath Acceleration mechanism, colliding with a boron target. Such experiments require a rigorous method to identify the reaction products (alpha particles) collected in detectors among a few other ion species such as protons or carbon ions, for example. CR-39 track detectors are widely used because they are mostly sensitive to ions and their efficiency is near 100%. We present a complete calibration of CR-39 track detector for protons, alpha particles, and carbon ions. We give measurements of their track diameters for energy ranging from hundreds of keV to a few MeV and for etching times between 1 and 8 h. We used these results to identify alpha particles in our experiments on proton-boron fusion reactions initiated by laser-accelerated protons. We show that their number clearly increases when the boron fuel is preformed in a plasma state.

  20. Isotope Production and Distribution Program. Financial statements, September 30, 1994 and 1993

    Energy Technology Data Exchange (ETDEWEB)

    Marwick, P.

    1994-11-30

    The attached report presents the results of the independent certified public accountants` audit of the Isotope Production and Distribution (IP&D) Program`s financial statements as of September 30, 1994. The auditors have expressed an unqualified opinion on IP&D`s 1994 statements. Their reports on IP&D`s internal control structure and on compliance with laws,and regulations are also provided. The charter of the Isotope Program covers the production and sale of radioactive and stable isotopes, byproducts, and related isotope services. Prior to October 1, 1989, the Program was subsidized by the Department of Energy through a combination of appropriated funds and isotope sales revenue. The Fiscal Year 1990 Appropriations Act, Public Law 101-101, authorized a separate Isotope Revolving Fund account for the Program, which was to support itself solely from the proceeds of isotope sales. The initial capitalization was about $16 million plus the value of the isotope assets in inventory or on loan for research and the unexpended appropriation available at the close of FY 1989. During late FY 1994, Public Law 103--316 restructured the Program to provide for supplemental appropriations to cover costs which are impractical to incorporate into the selling price of isotopes. Additional information about the Program is provided in the notes to the financial statements.

  1. Reactions sup 58,64 Ni( p ,. pi. sup + ) at 201 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Badala, A.; Barbera, R.; Palmeri, A.; Pappalardo, G.S.; Bonasera, A. (Istituto Nazionale di Fisica Nucleare, Corso Italia 57, 95129 Catania (Italy)); Riggi, F.; Adorno, A. (Istituto Nazionale di Fisica Nucleare and Dipartimento di Fisica dell' Universita di Catania, Corso Italia 57, 95129 Catania (Italy)); Bimbot, L. (Institut de Physique Nucleaire, Boite Postale 1, 91406 Orsay CEDEX (France))

    1992-08-01

    The production of positive and negative pions induced by 201 MeV protons on {sup 58}Ni and {sup 64}Ni isotopes has been studied. The double differential cross sections have been measured at the laboratory angles 22{degree}, 35{degree}, 55{degree}, 72{degree}, 90{degree}, 105{degree}, 120{degree}, 138{degree}, 155{degree} and from 20 MeV kinetic energy up to the kinematical limit. Features of the double differential cross sections relative to the two targets are discussed and compared to results obtained at higher incident energies.

  2. Excitation functions of 85Rb(p,xn)(85m,g,83,82,81)Sr reactions up to 100 MeV: integral tests of cross section data, comparison of production routes of 83Sr and thick target yield of 82Sr.

    Science.gov (United States)

    Kastleiner, S; Qaim, S M; Nortier, F M; Blessing, G; van der Walt, T N; Coenen, H H

    2002-05-01

    The beta+ emitter 83Sr (T(1/2) = 32.4 h, Ebeta+ = 1.23 MeV, Ibeta+ = 24%) is a potentially useful radionuclide for therapy planning prior to the use of the beta+ emitter 89Sr (T(1/2) = 50.5 d). In order to investigate its production possibility, cross section measurements on the 85Rb(p,xn)-reactions, leading to the formation of the isotopes (85m,g)Sr, 83Sr, 82Sr and 81Sr, were carried out using the stacked-foil technique. In a few cases, the products were separated via high-performance liquid chromatography. For 82Sr, both gamma-ray and X-ray spectrometry were applied; in other cases only gamma-ray spectrometry was used. From the measured excitation functions, the expected yields were calculated. For the energy range Ep = 37 --> 30 MeV the 83Sr yield amounts to 160 MBq/microA h and the level of the 85gSr (T(1,2) = 64.9 d) and 82Sr (T(1/2) = 25.5 d) impurities to functions. The results of the 85Rb(p,3n)83Sr reaction were compared with the data on the production of 83Sr via the 82Kr(3He,2n)-process. In the energy range E3Hc = 18 --> 10 MeV the theoretical yield of 83Sr amounts to 5 MBq/microA h and the 82Sr impurity to about 0.2%. The method of choice for the production of 83Sr is thus the 85Rb(p,3n)-process, provided a 40 MeV cyclotron is available. During this study some supplementary information on the yield and purity of 82Sr was also obtained.

  3. Double differential cross section for light mass fragment production on tens of MeV proton, deuteron, helium and carbon induced reactions

    Science.gov (United States)

    Sanami, Toshiya; Yamaguchi, Yuji; Uozumi, Yusuke; Hagiwara, Masayuki; Koba, Yusuke

    2017-09-01

    Double differential cross sections (DDXs) of light mass fragment (LMFs - Li,Be,B,C,N and O) productions were measured for tens of MeV proton, deuteron helium and carbon induced reactions on Be, C, Al, Ti and Cu targets. The incident energies for the measurements were chosen to allow us to compare DDXs with same incident energy but different projectiles on various targets. Systematic data were obtained to see the differences between projectile energies, particles, targets and emitted particles. From the comparison, reaction processes of not only evaporation from complete fusion nucleus, but also scattering, pickup, stripping and projectile fragmentation were observed.

  4. Neutron production at 0{degree} from the {sup 40}Ca+H reaction at E{sub lab}=357A and 565A MeV

    Energy Technology Data Exchange (ETDEWEB)

    Tuve, C.; Albergo, S.; Boemi, D.; Caccia, Z.; Costa, S.; Insolia, A.; Potenza, R.; Reito, S.; Romanski, J.; Russo, G.V. [Universita di Catania and INFN - I, 95129 Catania (Italy); Cronqvist, M.; Lindstrom, P.J. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Chen, C.; Guzik, T.G.; Tull, C.E.; Wefel, J.P. [Louisiana State University, Baton Rouge, Louisiana 70803 (United States); Crawford, H.J.; Engelage, J.; Greiner, L. [Space Science Laboratory, University of California, Berkeley, California 94720 (United States); Knott, C.N.; Waddington, C.J. [University of Minnesota, Minneapolis, Minnesota 55455 (United States); Webber, W.R. [University of New Mexico, Las Cruces, New Mexico 88003 (United States); Soutoul, A.; Testard, O. [Service dAstrophysique, CEN, 91191 Saclay (France); Mitchell, J.W. [NASA/Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States)

    1997-08-01

    Neutrons produced in the {sup 40}Ca+H reaction at E{sub lab}=357A and 565A MeV have been detected using a three-module version of the multifunctional neutron spectrometer MUFFINS. The detector covered a narrow angular range around the beam in the forward direction (0{degree}{minus}3.2{degree}). Semi-inclusive neutron production cross sections, at the two energies, are reported together with neutron energy spectra, angular, rapidity, and transverse momentum distributions. Comparison with a Boltzmann-Nordheim-Vlasov approach + phase space coalescence model is discussed. {copyright} {ital 1997} {ital The American Physical Society}

  5. Transmutation of Isotopes --- Ecological and Energy Production Aspects

    Science.gov (United States)

    Gudowski, Waclaw

    2000-01-01

    This paper describes principles of Accelerator-Driven Transmutation of Nuclear Wastes (ATW) and gives some flavour of the most important topics which are today under investigations in many countries. An assessment of the potential impact of ATW on a future of nuclear energy is also given. Nuclear reactors based on self-sustained fission reactions --- after spectacular development in fifties and sixties, that resulted in deployment of over 400 power reactors --- are wrestling today more with public acceptance than with irresolvable technological problems. In a whole spectrum of reasons which resulted in today's opposition against nuclear power few of them are very relevant for the nuclear physics community and they arose from the fact that development of nuclear power had been handed over to the nuclear engineers and technicians with some generically unresolved problems, which should have been solved properly by nuclear scientists. In a certain degree of simplification one can say, that most of the problems originate from very specific features of a fission phenomenon: self-sustained chain reaction in fissile materials and very strong radioactivity of fission products and very long half-life of some of the fission and activation products. And just this enormous concentration of radioactive fission products in the reactor core is the main problem of managing nuclear reactors: it requires unconditional guarantee for the reactor core integrity in order to avoid radioactive contamination of the environment; it creates problems to handle decay heat in the reactor core and finally it makes handling and/or disposal of spent fuel almost a philosophical issue, due to unimaginable long time scales of radioactive decay of some isotopes. A lot can be done to improve the design of conventional nuclear reactors (like Light Water Reactors); new, better reactors can be designed but it seems today very improbable to expect any radical change in the public perception of conventional

  6. Lead Contamination in Cocoa and Cocoa Products: Isotopic Evidence of Global Contamination

    National Research Council Canada - National Science Library

    Charley W. Rankin; Jerome O. Nriagu; Jugdeep K. Aggarwal; Toyin A. Arowolo; Kola Adebayo; A. Russell Flegal

    2005-01-01

    In this article we present lead concentrations and isotopic compositions from analyses of cocoa beans, their shells, and soils from six Nigerian cocoa farms, and analyses of manufactured cocoa and chocolate products...

  7. Isotope Production Facility Conceptual Thermal-Hydraulic Design Review and Scoping Calculations

    Energy Technology Data Exchange (ETDEWEB)

    Pasamehmetoglu, K.O.; Shelton, J.D.

    1998-08-01

    The thermal-hydraulic design of the target for the Isotope Production Facility (IPF) is reviewed. In support of the technical review, scoping calculations are performed. The results of the review and scoping calculations are presented in this report.

  8. 77 FR 32146 - Safety Evaluation Report, International Isotopes Fluorine Products, Inc., Fluorine Extraction...

    Science.gov (United States)

    2012-05-31

    ... possess and use source material for a fluorine extraction and depleted uranium deconversion facility. The... COMMISSION Safety Evaluation Report, International Isotopes Fluorine Products, Inc., Fluorine Extraction Process and Depleted Uranium Deconversion Plan, Lea County, NM AGENCY: Nuclear Regulatory...

  9. Production cross-sections of radionuclides from α-induced reactions on natural copper up to 50MeV.

    Science.gov (United States)

    Usman, Ahmed Rufai; Khandaker, Mayeen Uddin; Haba, Hiromitsu; Otuka, Naohiko; Murakami, Masashi; Komori, Yukiko

    2016-08-01

    The excitation functions were measured for the (nat)Cu(α,x)(66,67)Ga,(65)Zn,(57,58,60)Co reactions in the energy range of 16.5 -50MeV. A conventional stacked-foil activation technique combined with HPGe γ-ray spectrometry was employed to determine cross-sections. The measured cross-sections were critically compared with relevant previous experimental data and also with the evaluated data in the TENDL-2014 library. Present results confirmed some of the previous experimental data, whereas only a partial agreement was found with the evaluated data. The measured data are useful for reducing the existing discrepancies in the literature, to improve the nuclear reaction model codes, and to enrich the experimental database towards various applications.

  10. Stable isotope production in the former USSR by electromagnetic separation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Kaschejev, N.A. (Group of Enterprises ' Electrochimpribor' , Ekaterinburg (Russian Federation)); Polyakov, L.A. (Group of Enterprises ' Electrochimpribor' , Ekaterinburg (Russian Federation)); Tunin, V.V. (Group of Enterprises ' Electrochimpribor' , Ekaterinburg (Russian Federation))

    1993-09-15

    The present paper gives a brief review of the status of electromagnetic isotope separation techniques in the former USSR. It describes the basic specifications of the equipment as well as the general scheme of the production process, and considers questions relating to the chemical processing of isotopic material and analytical control technique. Finally, a summary is given of the main separation data obtained during the last ten years, and the prospects of future development and of enhancing the economical effectiveness of isotope production are discussed. (orig.)

  11. Stable isotope production in the former USSR by electromagnetic separation techniques

    Science.gov (United States)

    Kaschejev, N. A.; Polyakov, L. A.; Tunin, V. V.

    1993-09-01

    The present paper gives a brief review of the status of electromagnetic isotope separation techniques in the former USSR. It describes the basic specifications of the equipment as well as the general scheme of the production process, and considers questions relating to the chemical processing of isotopic material and analytical control techniques. Finally, a summary is given of the main separation data obtained during the last ten years, and the prospects of future development and of enhancing the economical effectiveness of isotope production are discussed.

  12. 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.

  13. Activation cross-sections of longer lived products of proton induced nuclear reactions on manganese up to 70 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Ditrói, F., E-mail: ditroi@atomki.hu [Institute for Nuclear Research, Hungarian Academy of Sciences (ATOMKI), Debrecen (Hungary); Tárkányi, F.; Takács, S. [Institute for Nuclear Research, Hungarian Academy of Sciences (ATOMKI), Debrecen (Hungary); Hermanne, A. [Cyclotron Laboratory, Vrije Universiteit Brussel (VUB), Brussels (Belgium); Yamazaki, H.; Baba, M.; Mohammadi, A. [Cyclotron Radioisotope Center (CYRIC) Tohoku University, Sendai (Japan)

    2013-08-01

    Highlights: •Experimental excitation function of proton induced reactions on manganese up to 70 MeV. •Model code calculations with EMPIRE-3 and TALYS (TENDL-2012). •Integral production yield calculation. •Thin Layer Activation (TLA) curves for {sup 54}Mn and {sup 51}Cr. •Tabulated experimental results. -- Abstract: In the frame of a systematic study of the activation cross-sections of the proton induced nuclear reactions, excitation functions of the {sup 55}Mn(p,x){sup 54,52g}Mn, {sup 51}Cr and {sup 48}V were measured up to 70 MeV. Cross-sections were measured with the activation method using the stacked foil irradiation technique and high resolution γ-ray spectrometry. The experimental data are analyzed and compared to the earlier results and to the prediction of the EMPIRE-3 as well as the TALYS theoretical model code in the TENDL-2012 library. From the measured cross-section data integral production yields were calculated. Practical applications of the cross-sections e.g. for thin layer activation are discussed.

  14. Study of medical isotope production facility stack emissions and noble gas isotopic signature using automatic gamma-spectra analysis platform

    Science.gov (United States)

    Zhang, Weihua; Hoffmann, Emmy; Ungar, Kurt; Dolinar, George; Miley, Harry; Mekarski, Pawel; Schrom, Brian; Hoffman, Ian; Lawrie, Ryan; Loosz, Tom

    2013-04-01

    The nuclear industry emissions of the four CTBT (Comprehensive Nuclear-Test-Ban Treaty) relevant radioxenon isotopes are unavoidably detected by the IMS along with possible treaty violations. Another civil source of radioxenon emissions which contributes to the global background is radiopharmaceutical production companies. To better understand the source terms of these background emissions, a joint project between HC, ANSTO, PNNL and CRL was formed to install real-time detection systems to support 135Xe, 133Xe, 131mXe and 133mXe measurements at the ANSTO and CRL 99Mo production facility stacks as well as the CANDU (CANada Deuterium Uranium) primary coolant monitoring system at CRL. At each site, high resolution gamma spectra were collected every 15 minutes using a HPGe detector to continuously monitor a bypass feed from the stack or CANDU primary coolant system as it passed through a sampling cell. HC also conducted atmospheric monitoring for radioxenon at approximately 200 km distant from CRL. A program was written to transfer each spectrum into a text file format suitable for the automatic gamma-spectra analysis platform and then email the file to a server. Once the email was received by the server, it was automatically analysed with the gamma-spectrum software UniSampo/Shaman to perform radionuclide identification and activity calculation for a large number of gamma-spectra in a short period of time (less than 10 seconds per spectrum). The results of nuclide activity together with other spectrum parameters were saved into the Linssi database. This database contains a large amount of radionuclide information which is a valuable resource for the analysis of radionuclide distribution within the noble gas fission product emissions. The results could be useful to identify the specific mechanisms of the activity release. The isotopic signatures of the various radioxenon species can be determined as a function of release time. Comparison of 133mXe and 133Xe activity

  15. Plasma separation process facility for large-scale stable isotope production

    Energy Technology Data Exchange (ETDEWEB)

    Bigelow, T.S.; Collins, E.D.; Tracy, J.G. [Oak Ridge National Lab., TN (United States)

    1997-12-01

    A facility for large-scale separation of stable isotopes using the plasma separation process (PSP) is under development at the Oak Ridge National Laboratory. The PSP is capable of separating isotopes at a large throughput rate with medium purity product and at relatively low cost. The PSP has a number of convenient features that make it an attractive technology for general isotope separation purposes. Several isotopes for medical and industrial applications, including {sup 102}Pd, {sup 98}Mo, {sup 203}Tl, {sup 184}W, and others, are expected to be processed in this facility. The large throughput and low processing cost of the PSP will likely lead to new applications for stable isotopes. A description of this facility and its typical throughput capability is presented here.

  16. Fission Product Yields of 233U, 235U, 238U and 239Pu in Fields of Thermal Neutrons, Fission Neutrons and 14.7-MeV Neutrons

    Science.gov (United States)

    Laurec, J.; Adam, A.; de Bruyne, T.; Bauge, E.; Granier, T.; Aupiais, J.; Bersillon, O.; Le Petit, G.; Authier, N.; Casoli, P.

    2010-12-01

    The yields of more than fifteen fission products have been carefully measured using radiochemical techniques, for 235U(n,f), 239Pu(n,f) in a thermal spectrum, for 233U(n,f), 235U(n,f), and 239Pu(n,f) reactions in a fission neutron spectrum, and for 233U(n,f), 235U(n,f), 238U(n,f), and 239Pu(n,f) for 14.7 MeV monoenergetic neutrons. Irradiations were performed at the EL3 reactor, at the Caliban and Prospero critical assemblies, and at the Lancelot electrostatic accelerator in CEA-Valduc. Fissions were counted in thin deposits using fission ionization chambers. The number of fission products of each species were measured by gamma spectrometry of co-located thick deposits.

  17. Production cross-sections of long-lived radionuclides in deuteron-induced reactions on natural zinc up to 23 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Khandaker, Mayeen Uddin, E-mail: mu_khandaker@yahoo.com [Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia); Haba, Hiromitsu; Murakami, Masashi [Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan); Otuka, Naohiko [Nuclear Data Section, Division of Physical and Chemical Sciences, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, A-1400 Vienna (Austria)

    2015-03-01

    Production cross-sections of long-lived radionuclides {sup 66,67}Ga, {sup 64,67}Cu, {sup 65,69m}Zn, and {sup 58m+g}Co via a deuteron irradiation on a natural zinc target were measured up to 23 MeV using a stacked-foil activation technique combined with HPGe γ-ray spectrometry. The present results showed partial agreements with the earlier experimental cross-sections and also with the theoretical data extracted from the TENDL-2013 library. Physical thick target yields of the investigated radionuclides were deduced using the measured cross-sections, and they found agreements with the directly measured ones in the literatures except for those reported by Dmitriev et al. for {sup 65}Zn. Optimal production pathways of the medically important {sup 67}Ga radionuclide using a low energy cyclotron are discussed.

  18. Changes in isotope ratios during domestic wastewater production

    NARCIS (Netherlands)

    Schilperoort, R. P. S.; Meijer, H. A. J.; Flamink, C. M. L.; Clemens, F. H. L. R.

    2007-01-01

    This paper presents considerations for the application of the natural water isotope method on catchment areas. For the estimation of the amount of infiltration and inflow in sewer systems the paper shows two applications in the Netherlands: one successful application on a relatively small catchment

  19. Single {pi}{sup -} production in np collisions for excess energies up to 90 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Bary, M.; Gillitzer, A.; Kilian, K.; Paul, N.; Ritman, J.; Roderburg, E.; Sefzick, T.; Ucar, A.; Wintz, P.; Wuestner, P. [Institut fuer Kernphysik, Forschungszentrum Juelich, Juelich (Germany); Brinkmann, K.T.; Dshemuchadse, S.; Freiesleben, H.; Jaekel, R.; Karsch, L.; Kuhlmann, E.; Schulte-Wissermann, M.; Ullrich, W. [Technische Universitaet Dresden, Institut fuer Kern- und Teilchenphysik, Dresden (Germany); Clement, H.; Doroshkevich, E.; Erhardt, A. [Universitaet Tuebingen, Physikalisches Institut, Tuebingen (Germany); Eyrich, W.; Pizzolotto, C.; Schroeder, W.; Teufel, A. [Universitaet Erlangen, Physikalisches Institut, Erlangen (Germany); Moeller, K.; Naumann, L. [Institut fuer Strahlenphysik, Forschungszentrum Dresden-Rossendorf, Dresden (Germany); Morsch, H.P. [Institut fuer Kernphysik, Forschungszentrum Juelich, Juelich (Germany); Andrzej Soltan Institute for Nuclear Studies, Warsaw (Poland)

    2008-04-15

    The quasifree reaction np{yields}pp{pi}{sup -} was studied in a kinematically complete experiment by bombarding a liquid-hydrogen target with a deuteron beam of momentum 1.85 GeV/c and analyzing the data along the lines of the spectator model. In addition to the three charged ejectiles the spectator proton was also detected in the large-acceptance time-of-flight spectrometer COSY-TOF. It was identified by its momentum and flight direction thus yielding access to the Fermi motion of the bound neutron and to the effective neutron 4-momentum vector P{sub n} which differed from event to event. A range of almost 90MeV excess energy above threshold was covered. Energy-dependent angular distributions, invariant-mass spectra as well as fully covered Dalitz plots were deduced. Sizeable pp FSI effects were found as were contributions of p and d partial waves. In comparison with existing literature data the results provide a sensitive test of the spectator model. The behavior of the elementary cross-section {sigma}{sub 01} close to threshold is discussed in view of new cross-section data. (orig.)

  20. Light-ion production in the interaction of 175 MeV quasi-mono-energetic neutrons with iron and with bismuth

    CERN Document Server

    Bevilacqua, R; Pomp, S; Andersson, P; Blomgren, J; Gustavsson, C; Hjalmarsson, A; Simutkin, V D; Österlund, M; Koning, A J; Prokofiev, A V; Hayashi, M; Hirayama, S; Naitou, Y; Watanabe, Y; Tippawan, U; Mashnik, S G; Kerby, L M; Lecolley, F -R; Marie, N; David, J -C; Leray, S

    2014-01-01

    Nuclear data for neutron-induced reactions in the intermediate energy range of 20 to 200 MeV are of great importance for the development of nuclear reaction codes since little data exist in that range. Also several different applications benefit from such data, notably accelerator-driven incineration of nuclear waste. The Medley setup was used for a series of measurements of p, d, t, $^3$He and $\\alpha$-particle production by 175 MeV quasi-mono-energetic neutrons on various target nuclei. The measurements were performed at the The Svedberg Laboratory in Uppsala, Sweden. Eight detector telescopes placed at angles between 20$^\\circ$ and 160$^\\circ$ were used. Medley uses the $\\Delta E$-$\\Delta E$-$E$ technique to discriminate among the particle types and is able to measure double-differential cross sections over a wide range of particle energies. This paper briefly describes the experimental setup, summarizes the data analysis and reports on recent changes in the previously reported preliminary data set on bism...

  1. Activation cross-sections of longer lived products of deuteron induced nuclear reactions on ytterbium up to 40 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Tárkányi, F. [Institute for Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), Debrecen (Hungary); Ditrói, F., E-mail: ditroi@atomki.hu [Institute for Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), Debrecen (Hungary); Takács, S. [Institute for Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), Debrecen (Hungary); Hermanne, A. [Cyclotron Laboratory, Vrije Universiteit Brussel (VUB), Brussels (Belgium); Yamazaki, H.; Baba, M.; Mohammadi, A. [Cyclotron Radioisotope Center (CYRIC), Tohoku University, Sendai (Japan); Ignatyuk, A.V. [Institute of Physics and Power Engineering (IPPE), Obninsk (Russian Federation)

    2013-06-01

    Highlights: •Experimental excitation function of deuteron induced reactions on natural ytterbium up to 40 MeV. •Model code calculations with EMPIRE-D, ALICE-D and TALYS (TENDL-2011 and 2012). •Physical yield calculation. •Tabulated experimental results. •Discussion of medical and industrial applications. -- Abstract: In the frame of a systematic study of the activation cross-sections of the deuteron induced nuclear reactions, excitation functions of the {sup nat}Yb(d,xn){sup 177,173,172mg,171mg,170,169}Lu, {sup nat}Yb(d,x){sup 175,169}Yb and {sup nat}Yb(d,x){sup 173,172,168,167,165}Tm reactions are studied up to 40 MeV, a few of them for the first time. Cross-sections were measured with the activation method using a stacked foil irradiation technique and high resolution γ-ray spectrometry. The experimental data are analyzed and compared to the results of the theoretical model codes ALICE-IPPE, EMPIRE-II and TALYS. From the measured cross-section data integral production yields were calculated. Applications of the new cross-sections are discussed.

  2. Production of medical radioactive isotopes using KIPT electron driven subcritical facility

    Energy Technology Data Exchange (ETDEWEB)

    Talamo, Alberto [Nuclear Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States)], E-mail: alby@anl.gov; Gohar, Yousry [Nuclear Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States)

    2008-05-15

    Kharkov Institute of Physics and Technology (KIPT) of Ukraine in collaboration with Argonne National Laboratory (ANL) has a plan to construct an electron accelerator driven subcritical assembly. One of the facility objectives is the production of medical radioactive isotopes. This paper presents the ANL collaborative work performed for characterizing the facility performance for producing medical radioactive isotopes. First, a preliminary assessment was performed without including the self-shielding effect of the irradiated samples. Then, more detailed investigation was carried out including the self-shielding effect, which defined the sample size and location for producing each medical isotope. In the first part, the reaction rates were calculated as the multiplication of the cross section with the unperturbed neutron flux of the facility. Over fifty isotopes have been considered and all transmutation channels are used including (n, {gamma}), (n, 2n), (n, p), and ({gamma}, n). In the second part, the parent isotopes with high reaction rate were explicitly modeled in the calculations. Four irradiation locations were considered in the analyses to study the medical isotope production rate. The results show the self-shielding effect not only reduces the specific activity but it also changes the irradiation location that maximizes the specific activity. The axial and radial distributions of the parent capture rates have been examined to define the irradiation sample size of each parent isotope.

  3. Production of isotopically labeled heterologous proteins in non-E. coli prokaryotic and eukaryotic cells.

    Science.gov (United States)

    Takahashi, Hideo; Shimada, Ichio

    2010-01-01

    The preparation of stable isotope-labeled proteins is necessary for the application of a wide variety of NMR methods, to study the structures and dynamics of proteins and protein complexes. The E. coli expression system is generally used for the production of isotope-labeled proteins, because of the advantages of ease of handling, rapid growth, high-level protein production, and low cost for isotope-labeling. However, many eukaryotic proteins are not functionally expressed in E. coli, due to problems related to disulfide bond formation, post-translational modifications, and folding. In such cases, other expression systems are required for producing proteins for biomolecular NMR analyses. In this paper, we review the recent advances in expression systems for isotopically labeled heterologous proteins, utilizing non-E. coli prokaryotic and eukaryotic cells.

  4. Methane Production Pathways in a California Rice Paddy: Isotopic Evidence for Substantial CO2 Reduction as Cause for Isotopically Light Emitted CH4 Carbon

    Science.gov (United States)

    Tyler, S. C.; McMillan, A. M.; Bearden, K.; Chidthaisong, A.; Macalady, J.

    2003-12-01

    We report measurements of δ 13C of emitted CH4 and sediment CH4 and CO2 during the 1999 rice-growing season near Maxwell, CA. Two treatments, one with rice straw incorporated from the previous season and one without rice straw were studied. The δ 13C value of emitted CH4 was consistently lighter isotopically (-67‰ to -83‰ throughout the season) in both straw incorporated and straw removed (burned) plots than in fields we have studied in Texas, Kenya, and Japan. Measured isotopic values of the production zone CH4 were compared to a two-point mixing curve representative of isotopic CH4 produced from either pure methyl-group fermentation or CO2 reduction pathways to partition the production pathways and to track seasonal changes in the production processes. Our sediment CH4 and CO2 isotope data indicate that fermentation was rarely the dominant methanogenic pathway - on the contrary CO2 reduction with H2 was more prevalent than fermentation methanogenesis throughout most of the season. The relatively isotopically light CH4 emitted by the paddy fields is also a product of oxidation and stem-transport processes which have isotopic effects of their own. These effects are discussed in context with the methanogenic isotope effects to provide a complete picture of the paddy field CH4 carbon isotope system.

  5. Characteristics and applications of isotopes in products from organic matter in sedimentary rocksby simulated thermal experiments

    Institute of Scientific and Technical Information of China (English)

    陈安定; 张文正; 徐永昌

    1995-01-01

    Isotopic compositions of carbon in the products obtained respectively from 25 sedimentary rocks at an early stage of maturation by the simulated thermogenetic hydrocarbons experiments have been determined. The fractional effect of methane carbon isotope during the thermal maturation of organic matter is observed. Based on the experimental data, the relative equations between δ13C and R0 were established and have been used for differentiation of origins of various kinds of natural gases in the Shan-Gan-Ning Basin.

  6. Production of spin-controlled rare isotope beams

    CERN Document Server

    Ichikawa, Y; Ishii, Y; Furukawa, T; Yoshimi, A; Kameda, D; Watanabe, H; Aoi, N; Asahi, K; Balabanski, D L; Chevrier, R; Daugas, J M; Fukuda, N; Georgiev, G; Hayashi, H; Iijima, H; Inabe, N; Inoue, T; Ishihara, M; Kubo, T; Nanao, T; Ohnishi, T; Suzuki, K; Tsuchiya, M; Takeda, H; Rajabali, M M

    2012-01-01

    The degree of freedom of spin in quantum systems serves as an unparalleled laboratory where intriguing quantum physical properties can be observed, and the ability to control spin is a powerful tool in physics research. We propose a novel method for controlling spin in a system of rare isotopes which takes advantage of the mechanism of the projectile fragmentation reaction combined with the momentum-dispersion matching technique. The present method was verified in an experiment at the RIKEN RI Beam Factory, in which a degree of alignment of 8% was achieved for the spin of a rare isotope Al-32. The figure of merit for the present method was found to be greater than that of the conventional method by a factor of more than 50.

  7. Principles and limitations of stable isotopes in differentiating organic and conventional foodstuffs: 2. Animal products.

    Science.gov (United States)

    Inácio, Caio T; Chalk, Phillip M

    2017-01-02

    In this review, we examine the variation in stable isotope signatures of the lighter elements (δ(2)H, δ(13)C, δ(15)N, δ(18)O, and δ(34)S) of tissues and excreta of domesticated animals, the factors affecting the isotopic composition of animal tissues, and whether stable isotopes may be used to differentiate organic and conventional modes of animal husbandry. The main factors affecting the δ(13)C signatures of livestock are the C3/C4 composition of the diet, the relative digestibility of the diet components, metabolic turnover, tissue and compound specificity, growth rate, and animal age. δ(15)N signatures of sheep and cattle products have been related mainly to diet signatures, which are quite variable among farms and between years. Although few data exist, a minor influence in δ(15)N signatures of animal products was attributed to N losses at the farm level, whereas stocking rate showed divergent findings. Correlations between mode of production and δ(2)H and δ(18)O have not been established, and only in one case of an animal product was δ(34)S a satisfactory marker for mode of production. While many data exist on diet-tissue isotopic discrimination values among domesticated animals, there is a paucity of data that allow a direct and statistically verifiable comparison of the differences in the isotopic signatures of organically and conventionally grown animal products. The few comparisons are confined to beef, milk, and egg yolk, with no data for swine or lamb products. δ(13)C appears to be the most promising isotopic marker to differentiate organic and conventional production systems when maize (C4) is present in the conventional animal diet. However, δ(13)C may be unsuitable under tropical conditions, where C4 grasses are abundant, and where grass-based husbandry is predominant in both conventional and organic systems. Presently, there is no universal analytical method that can be applied to differentiate organic and conventional animal products.

  8. Production of high-purity isotopes by electromagnetic separation; Production electromagnetique d'isotope tres purs

    Energy Technology Data Exchange (ETDEWEB)

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

    1958-07-01

    Improvement in isotopic purity of nuclides prepared by electromagnetic separation is searched into the principle of cascades of monochromators. The principal drawback of which is to allow the separation of only one isotope at a time. The electromagnetic separator of Saclay is equipped with an electrostatic post-analyzer, which is described. Significant results are obtained, concerning isotopic enhancements of uranium-235 and mercury-204. A schema of isotopic contagion is then proposed, the basis of it is the scattering of the primary ions in the residual atmosphere of the separator chamber. The most frequent type of collisions being accompanied by neutralisation of the ions, the schema explains the efficiency of the second stage. As a matter of conclusion, some particularities concerning the routine work at a high enhancement, small output machine, are given. (author) [French] L'accroissement de la purete isotopique des especes nucleaires preparees par separation electromagnetique est recherche dans l'emploi du principe des cascades de monochromateurs, moyennant la servitude de ne collecter qu'un isotope a la fois. Le separateur electromagnetique de Saclay est equipe dans ce but d'un post-analyseur electrostatique, qui est decrit. Des resultats significatifs sont donnes, portant sur les enrichissements obtenus dans les separations d'uranium-235 et de mercure-204. Un schema de contagion isotopique est propose. Il est fonde sur la diffusion a petit angle accompagnant la neutralisation des faisceaux primaires par collision avec le gaz residuel. Ce schema permet d'expliquer l'efficacite de l'etage electrostatique. En matiere de conclusion, la methode d'exploitation d'une machine a faible debit et a haut enrichissement est donnee. (auteur)

  9. Real-time Stack Monitoring at the BaTek Medical Isotope Production Facility

    Energy Technology Data Exchange (ETDEWEB)

    McIntyre, Justin I.; Agusbudiman, A.; Cameron, Ian M.; Dumais, Johannes R.; Eslinger, Paul W.; Gheddou, A.; Khrustalev, Kirill; Marsoem, Pujadi; Miley, Harry S.; Nikkinen, Mika; Prinke, Amanda M.; Ripplinger, Mike D.; Schrom, Brian T.; Sliger, William A.; Stoehlker, Ulrich; Suhariyono, G.; Warren, Glen A.; Widodo, Susilo; Woods, Vincent T.

    2016-04-01

    Radioxenon emissions from radiopharmaceutical production are a major source of background concentrations affecting the radioxenon detection systems of the International Monitoring System (IMS). Collection of real-time emissions data from production facilities makes it possible to screen out some medical isotope signatures from the IMS radioxenon data sets. This paper describes an effort to obtain and analyze real-time stack emissions data with the design, construction and installation of a small stack monitoring system developed by a joint CTBTO-IDC, BATAN, and PNNL team at the BaTek medical isotope production facility near Jakarta, Indonesia.

  10. Recent developments in application of stable isotope analysis on agro-product authenticity and traceability.

    Science.gov (United States)

    Zhao, Yan; Zhang, Bin; Chen, Gang; Chen, Ailiang; Yang, Shuming; Ye, Zhihua

    2014-02-15

    With the globalisation of agro-product markets and convenient transportation of food across countries and continents, the potential for distribution of mis-labelled products increases accordingly, highlighting the need for measures to identify the origin of food. High quality food with identified geographic origin is a concern not only for consumers, but also for agriculture farmers, retailers and administrative authorities. Currently, stable isotope ratio analysis in combination with other chemical methods gradually becomes a promising approach for agro-product authenticity and traceability. In the last five years, a growing number of research papers have been published on tracing agro-products by stable isotope ratio analysis and techniques combining with other instruments. In these reports, the global variety of stable isotope compositions has been investigated, including light elements such as C, N, H, O and S, and heavy isotopes variation such as Sr and B. Several factors also have been considered, including the latitude, altitude, evaporation and climate conditions. In the present paper, an overview is provided on the authenticity and traceability of the agro-products from both animal and plant sources by stable isotope ratio analysis.

  11. Activation cross-sections of longer lived products of proton induced nuclear reactions on manganese up to 70 MeV

    CERN Document Server

    Ditrói, F; Takács, S; Hermanne, A; Yamazaki, H; Baba, M; Mohammadi, A

    2013-01-01

    In the frame of a systematic study of the activation cross-sections of the proton induced nuclear reactions, excitation functions of the 55Mn(p,x)154,152gMn,51Cr and 48V were measured up to 70 MeV. Cross-sections were measured with the activation method using a stacked foil irradiation technique and high resolution gamma-ray spectrometry. The experimental data are analyzed and compared to the earlier results and to the prediction of the EMPIRE-3 as well as the TALYS theoretical model code in the TENDL-2012 library. From the measured cross-section data integral production yields were calculated. Practical applications of the cross-sections are discussed.

  12. Authentication of fishery and aquaculture products by multi-element and stable isotope analysis.

    Science.gov (United States)

    Li, Li; Boyd, Claude E; Sun, Zhenlong

    2016-03-01

    The market of fishery and aquaculture products is globalized with increasing numbers of mislabeled products. This highlights the need for approaches to indentify the origin of these products. Among the measures used to identify the origin of other agro-products, multi-element and stable isotope analysis are promising approaches to identify the authenticity and traceability of fishery and aquaculture products. The present paper reviews the use of multi-element and stable isotope analysis to determine the origin of fishery and aquaculture products. Principles and limitations of each method will be illustrated and perspectives for traceability of fishery and aquaculture products will be discussed. The aim of this review is to mediate fundamental knowledge for the interpretation of experimental data on authentication of aquaculture products.

  13. Natural carbon isotopes used to study methane consumption and production in soil

    DEFF Research Database (Denmark)

    Ambus, Per; Andersen, Bertel Lohmann; Kemner, Marianne;

    2002-01-01

    Changes in the isotopic composition of carbon can be used to reveal simultaneous occurrence of methane production and oxidation in soil. The method is conducted in laboratory jar experiments as well as in the field by using flux chambers. Simultaneous occurrence of production and oxidation...

  14. Calculation of isotopic mass and energy production by a matrix operator method. [Volterra method of the multiplicative integral

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C.E.

    1976-08-01

    The Volterra method of the multiplicative integral is used to determine the isotopic density, mass, and energy production in linear systems. The solution method, assumptions, and limitations are discussed. The method allows a rapid accurate calculation of the change in isotopic density, mass, and energy production independent of the magnitude of the time steps, production or decay rates, or flux levels.

  15. Cascade units for neon isotope production by rectification

    Science.gov (United States)

    Bondarenko, V. L.; Simonenko, Yu. M.; Diachenko, O. V.; Matveyev, E. V.

    2013-05-01

    The basics of neon isotope separation by the distillation method at T = 28 K are discussed. The required numbers of transfer units at the top and bottom column sections are calculated for different loads. The experimental characteristics of packed rectification columns are presented and examples of the cascade are discussed. A configuration for a cryogenic circuit based on a high-pressure throttle neon cycle with intermediate nitrogen cooling is presented. The necessity for and the technical feasibility of creating a driver pressure difference between the columns for different stages are demonstrated.

  16. Measurement of (43)Sc and (44)Sc production cross-section with an 18MeV medical PET cyclotron.

    Science.gov (United States)

    Carzaniga, Tommaso Stefano; Auger, Martin; Braccini, Saverio; Bunka, Maruta; Ereditato, Antonio; Nesteruk, Konrad Pawel; Scampoli, Paola; Türler, Andreas; van der Meulen, Nicholas

    2017-11-01

    (43)Sc and (44)Sc are positron emitter radionuclides that, in conjunction with the β(-) emitter (47)Sc, represent one of the most promising possibilities for theranostics in nuclear medicine. Their availability in suitable quantity and quality for medical applications is an open issue and their production with medical cyclotrons represents a scientific and technological challenge. For this purpose, an accurate knowledge of the production cross sections is mandatory. In this paper, we report on the cross section measurement of the reactions (43)Ca(p,n)(43)Sc, (44)Ca(p,2n) (43)Sc, (46)Ti(p,α)(43)Sc, and (44)Ca(p,n)(44)Sc at the Bern University Hospital cyclotron. A study of the production yield and purity performed by using commercially available enriched target materials is also presented. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Isotope materials availability and services for target production at the Oak Ridge National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Ratledge, J.E.; Dahl, T.L.; Ottinger, C.L.; Aaron, W.S.; Adair, H.L.

    1986-01-01

    Materials available through the Isotope Distribution Program include separated stable isotopes, byproduct radiosotopes, and research quantities of source and special nuclear materials. Isotope products are routinely available in the forms listed in the product description section of the Isotopes Products and Services Catalog distributed by the Oak Ridge National Laboratory (ORNL). Different forms can be provided in some cases, usually at additional cost. Routinely available services include cyclotron target irradiations, fabrication of special physical forms, source encapsulation, ion implantation, and special purifications. Materials and services that are not offered as part of the routine distribution program may be made available from commercial sources in the United States. Specific forms of isotopic research materials include thin films and foils for use as accelerator targets, metal or other compounds in the form of bars or wires, and metal sheets. Methods of fabrication include evaporation, sputtering, rolling, electrolytic deposition, pressing, sintering, and casting. High-purity metal forms of plutonium, americium, and curium are prepared by vacuum reduction/distillation. Both fissionable and nonfissionable neutron dosimeters are prepared for determining the neutron energy spectra, flux, and fluence at various locations within a reactor. Details on what materials are available and how the materials and related services can be obtained from ORNL are described.

  18. Advances in the production of isotopes and radiopharmaceuticals at the Atomic Energy Corporation of South Africa

    Energy Technology Data Exchange (ETDEWEB)

    Louw, P.A.; De Villiers, W.Y.Z.; Jarvis, N.V. [Atomic Energy Corporation of South Africa Ltd, Pretoria (South Africa)

    1997-10-01

    The Atomic Energy Corporation of South Africa Ltd (AEC) owns and operates the 20 MW research reactor, SAFARI-1. Utilisation of the reactor has in recent years changed from research and materials testing to the production of isotopes. The most important breakthrough achieved in recent years is the production of high quality fission 99Mo. This has been produced routinely since April 1993 and supplied to clients across the world. A capability for the reliable production of 1000 Ci of 99Mo per week (calibrated for six days after production) has been proven. The AEC has also established facilities to produce its own 99mTc generators together with a most of radiopharmaceutical kits for diagnostic nuclear medicine purposes. The production of {sup 153}Sm and {sup 131}I (tellurium oxide route) has been operational for many years. Applications include therapeutic radiopharmaceuticals such as {sup 153}Sm-EDTMP for bone cancer pain palliation, {sup 13`}I-Lipiodol for liver cancer and {sup 131}I capsules for thyroid treatment. Facilities for the production of other isotopes such as {sup 131}I (from fission), {sup 32}P and {sup 35}S are in various stages of completion. Extensive analytical methods and equipment have been developed and are routinely used to certify the quality of exported isotopes. Irradiation and encapsulation of {sup 192}Ir is also performed routinely at the AEC. Modern facilities allow for the production of isotopes such as {sup 131}Ba and {sup 140}La on an ad hoc basis. Quality assurance procedures based on ISO9000 were developed for all aspects of the production of the various isotopes. Documentation, such as Drug Master Files, required by authorities in various countries has also been submitted and accepted 15 refs., 1 tab., 2 figs.

  19. The South African National Accelerator Centre: particle therapy and isotope production programmes

    Science.gov (United States)

    Jones, D. T. L.; Mills, S. J.

    1998-06-01

    The National Accelerator Centre (NAC) provides facilities for basic and applied research, radioisotope production and particle therapy. To date, 851 patients have been treated on the 66 MeV p+Be isocentric neutron therapy unit while 191 patients have been treated (mainly for intracranial conditions) on the 200 MeV horizontal proton beam facility. A variety of radioisotopes such as 67Ga, 81Rb/ 81Kr, 111In, 123I, and 201Tl are produced on a regular weekly basis, and more than 1000 consignments of radiopharmaceuticals prepared from these radioisotopes are supplied to more than 30 hospitals and private practices throughout South Africa each year. Some non-medical radioisotopes are also produced.

  20. Isotopic Dependence of the Nuclear Caloric Curve

    Science.gov (United States)

    Sfienti, C.; Adrich, P.; Aumann, T.; Bacri, C. O.; Barczyk, T.; Bassini, R.; Bianchin, S.; Boiano, C.; Botvina, A. S.; Boudard, A.; Brzychczyk, J.; Chbihi, A.; Cibor, J.; Czech, B.; de Napoli, M.; Ducret, J.-É.; Emling, H.; Frankland, J. D.; Hellström, M.; Henzlova, D.; Immè, G.; Iori, I.; Johansson, H.; Kezzar, K.; Lafriakh, A.; Le Fèvre, A.; Le Gentil, E.; Leifels, Y.; Lühning, J.; Łukasik, J.; Lynch, W. G.; Lynen, U.; Majka, Z.; Mocko, M.; Müller, W. F. J.; Mykulyak, A.; Orth, H.; Otte, A. N.; Palit, R.; Pawłowski, P.; Pullia, A.; Raciti, G.; Rapisarda, E.; Sann, H.; Schwarz, C.; Simon, H.; Sümmerer, K.; Trautmann, W.; Tsang, M. B.; Verde, G.; Volant, C.; Wallace, M.; Weick, H.; Wiechula, J.; Wieloch, A.; Zwiegliński, B.

    2009-04-01

    The A/Z dependence of projectile fragmentation at relativistic energies has been studied with the ALADIN forward spectrometer at SIS. A stable beam of Sn124 and radioactive beams of La124 and Sn107 at 600 MeV per nucleon have been used in order to explore a wide range of isotopic compositions. Chemical freeze-out temperatures are found to be nearly invariant with respect to the A/Z of the produced spectator sources, consistent with predictions for expanded systems. Small Coulomb effects (ΔT≈0.6MeV) appear for residue production near the onset of multifragmentation.

  1. Isotopic Dependence of the Nuclear Caloric Curve

    CERN Document Server

    Sfienti, C; Aumann, T; Bacri, C O; Barczyk, T; Bassini, R; Bianchin, S; Boiano, C; Botvina, A S; Boudard, A; Brzychczyk, J; Chbihi, A; Cibor, J; Czech, B; De Napoli, M; Ducret, J -E; Emling, H; Frankland, J D; Hellström, M; Henzlova, D; Imme, G; Iori, I; Johansson, H; Kezzar, K; Lafriakh, A; Le Fèvre, A; Gentil, E Le; Leifels, Y; Lühning, J; Lukasik, J; Lynch, W G; Lynen, U; Majka, Z; Mocko, M; Müller, W F J; Mykulyak, A; Orth, H; Otte, A N; Palit, R; Pawlowski, P; Pullia, A; Raciti, G; Rapisarda, E; Sann, H; Schwarz, C; Simon, H; Sümmerer, K; Trautmann, W; Tsang, M B; Verde, G; Volant, C; Wallace, M; Weick, H; Wiechula, J; Wieloch, A; Zwieglinski, B

    2009-01-01

    The A/Z dependence of projectile fragmentation at relativistic energies has been studied with the ALADIN forward spectrometer at SIS. A stable beam of 124Sn and radioactive beams of 124La and 107Sn at 600 MeV per nucleon have been used in order to explore a wide range of isotopic compositions. Chemical freeze-out temperatures are found to be nearly invariant with respect to the A/Z of the produced spectator sources, consistent with predictions for expanded systems. Small Coulomb effects (\\Delta T \\approx 0.6 MeV) appear for residue production near the onset of multifragmentation.

  2. Photofission product yields of {sup 238}U and {sup 239}Pu with 22-MeV bremsstrahlung

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Xianfei; Yang, Haori, E-mail: haori.yang@oregonstate.edu

    2016-06-11

    In homeland security and nuclear safeguards applications, non-destructive techniques to identify and quantify special nuclear materials are in great demand. Although nuclear materials naturally emit characteristic radiation (e.g. neutrons, γ-rays), their intensity and energy are normally low. Furthermore, such radiation could be intentionally shielded with ease or buried in high-level background. Active interrogation techniques based on photofission have been identified as effective assay approaches to address this issue. In designing such assay systems, nuclear data, like photofission product yields, plays a crucial role. Although fission yields for neutron-induced reactions have been well studied and readily available in various nuclear databases, data on photofission product yields is rather scarce. This poses a great challenge to the application of photofission techniques. In this work, short-lived high-energy delayed γ-rays from photofission of {sup 238}U were measured in between linac pulses. In addition, a list-mode system was developed to measure relatively long-lived delayed γ-rays from photofission of {sup 238}U and {sup 239}Pu after the irradiation. Time and energy information of each γ-ray event were simultaneously recorded by this system. Cumulative photofission product yields were then determined using the measured delayed γ-ray spectra.

  3. Investigation of sulphur isotope variation due to different processes applied during uranium ore concentrate production.

    Science.gov (United States)

    Krajkó, Judit; Varga, Zsolt; Wallenius, Maria; Mayer, Klaus; Konings, Rudy

    The applicability and limitations of sulphur isotope ratio as a nuclear forensic signature have been studied. The typically applied leaching methods in uranium mining processes were simulated for five uranium ore samples and the n((34)S)/n((32)S) ratios were measured. The sulphur isotope ratio variation during uranium ore concentrate (UOC) production was also followed using two real-life sample sets obtained from industrial UOC production facilities. Once the major source of sulphur is revealed, its appropriate application for origin assessment can be established. Our results confirm the previous assumption that process reagents have a significant effect on the n((34)S)/n((32)S) ratio, thus the sulphur isotope ratio is in most cases a process-related signature.

  4. Production of sup 5 sup 5 Co via the sup 5 sup 4 Fe(d, n)-process and excitation functions of sup 5 sup 4 Fe(d, t) sup 5 sup 3 Fe and sup 5 sup 4 Fe(d, alpha) sup 5 sup 2 sup m Mn reactions from threshold up to 13.8 MeV

    CERN Document Server

    Zaman, M R; Qaim, S M

    2003-01-01

    For production of the medically interesting beta; sup + -emitter sup 5 sup 5 Co (T sup 1 sup / sup 2 = 17.6 h) via the sup 5 sup 4 Fe(d, n)-reaction, 91.6% enriched sup 5 sup 4 Fe sub 2 O sub 3 , mixed with Al powder, was pressed to a pellet which could be irradiated with 14 MeV deuterons at 4 mu A in a water-cooled target system. A separation method was developed which led to > 99.9% pure sup 5 sup 5 Co and allowed a recovery of the enriched target material. For a target thickness of E sub d = 12.6 -> 5 MeV, the experimental thick target yield of sup 5 sup 5 Co after chemical separation amounted to about 13 MBq/mu A.h, which is about 60% of the theoretical value. In a 3 h irradiation at 4 mu A, the batch yield of sup 5 sup 5 Co achieved was 160 MBq (4.3 mCi). An 8 h irradiation could lead to a batch yield of about 400 MBq. The sup 5 sup 4 Fe(d, n) reaction leads to the highest purity sup 5 sup 5 Co but it is essential that the isotopic enrichment of the target is not less than 90%. In addition to the product...

  5. Technical note: Consistent calculation of aquatic gross production from oxygen triple isotope measurements

    Directory of Open Access Journals (Sweden)

    J. Kaiser

    2011-07-01

    Full Text Available Oxygen triple isotope measurements can be used to calculate aquatic gross oxygen production rates. Past studies have emphasised the appropriate definition of the 17O excess and often used an approximation to derive production rates from the 17O excess. Here, I show that the calculation can be phrased more consistently and without any approximations using the relative 17O/16O and 18O/16O isotope ratio differences (delta values directly. I call this the "dual delta method". The 17O excess is merely a mathematical construct and the derived production rate is independent of its definition, provided all calculations are performed with a consistent definition. I focus on the mixed layer, but also show how time series of triple isotope measurements below the mixed layer can be used to derive gross production.

    In the calculation of mixed layer productivity, I explicitly include isotopic fractionation during gas invasion and evasion, which requires the oxygen supersaturation s to be measured as well. I also suggest how bubble injection could be considered in the same mathematical framework. I distinguish between concentration steady state and isotopic steady state and show that only the latter needs to be assumed in the calculation. It is even possible to derive an estimate of the net production rate in the mixed layer that is independent of the assumption of concentration steady state.

    I review measurements of the parameters required for the calculation of gross production rates and show how their systematic uncertainties as well as the use of different published calculation methods can cause large variations in the production rates for the same underlying isotope ratios. In particular, the 17O excess of dissolved O2 in equilibrium with atmospheric O2 and the 17O excess of photosynthetic O2 need to

  6. Experimental validation of gallium production and isotope-dependent positron range correction in PET

    Energy Technology Data Exchange (ETDEWEB)

    Fraile, L.M., E-mail: lmfraile@ucm.es [Grupo de Física Nuclear, Dpto. Física Atómica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain); Herraiz, J.L.; Udías, J.M.; Cal-González, J.; Corzo, P.M.G.; España, S.; Herranz, E.; Pérez-Liva, M.; Picado, E.; Vicente, E. [Grupo de Física Nuclear, Dpto. Física Atómica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain); Muñoz-Martín, A. [Centro de Microanálisis de Materiales, Universidad Autónoma de Madrid, E-28049 Madrid (Spain); Vaquero, J.J. [Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III de Madrid (Spain)

    2016-04-01

    Positron range (PR) is one of the important factors that limit the spatial resolution of positron emission tomography (PET) preclinical images. Its blurring effect can be corrected to a large extent if the appropriate method is used during the image reconstruction. Nevertheless, this correction requires an accurate modelling of the PR for the particular radionuclide and materials in the sample under study. In this work we investigate PET imaging with {sup 68}Ga and {sup 66}Ga radioisotopes, which have a large PR and are being used in many preclinical and clinical PET studies. We produced a {sup 68}Ga and {sup 66}Ga phantom on a natural zinc target through (p,n) reactions using the 9-MeV proton beam delivered by the 5-MV CMAM tandetron accelerator. The phantom was imaged in an ARGUS small animal PET/CT scanner and reconstructed with a fully 3D iterative algorithm, with and without PR corrections. The reconstructed images at different time frames show significant improvement in spatial resolution when the appropriate PR is applied for each frame, by taking into account the relative amount of each isotope in the sample. With these results we validate our previously proposed PR correction method for isotopes with large PR. Additionally, we explore the feasibility of PET imaging with {sup 68}Ga and {sup 66}Ga radioisotopes in proton therapy.

  7. Experimental validation of gallium production and isotope-dependent positron range correction in PET

    Science.gov (United States)

    Fraile, L. M.; Herraiz, J. L.; Udías, J. M.; Cal-González, J.; Corzo, P. M. G.; España, S.; Herranz, E.; Pérez-Liva, M.; Picado, E.; Vicente, E.; Muñoz-Martín, A.; Vaquero, J. J.

    2016-04-01

    Positron range (PR) is one of the important factors that limit the spatial resolution of positron emission tomography (PET) preclinical images. Its blurring effect can be corrected to a large extent if the appropriate method is used during the image reconstruction. Nevertheless, this correction requires an accurate modelling of the PR for the particular radionuclide and materials in the sample under study. In this work we investigate PET imaging with 68Ga and 66Ga radioisotopes, which have a large PR and are being used in many preclinical and clinical PET studies. We produced a 68Ga and 66Ga phantom on a natural zinc target through (p,n) reactions using the 9-MeV proton beam delivered by the 5-MV CMAM tandetron accelerator. The phantom was imaged in an ARGUS small animal PET/CT scanner and reconstructed with a fully 3D iterative algorithm, with and without PR corrections. The reconstructed images at different time frames show significant improvement in spatial resolution when the appropriate PR is applied for each frame, by taking into account the relative amount of each isotope in the sample. With these results we validate our previously proposed PR correction method for isotopes with large PR. Additionally, we explore the feasibility of PET imaging with 68Ga and 66Ga radioisotopes in proton therapy.

  8. Sulfur isotopic characteristics of volcanic products from the September 2014 Mount Ontake eruption, Japan

    Science.gov (United States)

    Ikehata, Kei; Maruoka, Teruyuki

    2016-07-01

    Components and sulfur isotopic compositions of pyroclastic materials from the 2014 Mt. Ontake eruption were investigated. The volcanic ash samples were found to be composed of altered volcanic fragments, alunite, anhydrite, biotite, cristobalite, gypsum, ilmenite, kaolin minerals, native sulfur, orthopyroxene, plagioclase, potassium feldspar, pyrite, pyrophyllite, quartz, rutile, and smectite, and most of these minerals were likely derived from the acidic alteration zones of Mt. Ontake. The absence of juvenile material in the eruptive products indicates that the eruption was phreatic. The sulfur isotopic compositions of the water-leached sulfate, hydrochloric acid-leached sulfate, acetone-leached native sulfur, and pyrite of the samples indicate that these sulfur species were produced by disproportionation of magmatic SO2 in the hydrothermal system at temperatures of 270-281 °C. This temperature range is consistent with that inferred from the hydrothermal mineral assemblage (e.g., pyrophyllite and rutile) in the 2014 pyroclastic materials (200-300 °C). Except for the sulfur isotopic compositions of anhydrite, which may have been altered by incorporation of sulfate minerals in a fumarolic area with lower sulfur isotopic values into the underground materials during the 1979 eruption, no significant differences in the mineral assemblages and sulfur isotopic compositions of the pyroclastic materials were identified between the products of the 2014 and 1979 Ontake phreatic eruptions, which suggests geochemical similarities in the underlying hydrothermal systems before the 2014 and 1979 eruptions.

  9. Multi-Fragment Production in the 32S+58,64Ni Reactions at 11 A MeV

    Science.gov (United States)

    Gramegna, F.; Abbondanno, U.; Bonasera, A.; Bruno, M.; Casini, G.; Cavallaro, S.; Chiari, M.; D'Agostino, M.; Lanchais, A.; Margagliotti, G. V.; Mastinu, P. F.; Milazzo, P. M.; Moroni, A.; Nannini, A.; Ordine, A.; Ricci, R. A.; Tonetto, F.; Travaglini, L.; Vannini, G.; Vannucci, L.

    The characteristic features of the 32S+58,64Ni reaction at 11AMeV have been investigated to evidence the possible rise of multi-fragmentation processes at low excitation energies. The importance of such phenomena consists in the fact that they could represent the signature of a nuclear phase transition from a liquid to a gas region. Evidence of multi-fragment production is displayed by the present data; even if the yield of such events is compatible with the predictions of statistical models, the partition of the mass of the decaying system cannot be easily reproduced. Some preliminary indications of isospin effects are suggested by looking at the differences between the two reacting systems.

  10. Calculation of Production and Decay of Radio Isotopes for Future Irradiation Experiments and Ion Bea

    CERN Document Server

    M. Eller, J. Lettry, R. Catherall, T. Stora

    The design of future radioactive ion beam (RIB) facilities requires the forecast of radio isotope inventory after irradiation. At CERN ISOLDE we developed a software tool that estimates the roduction and activation of materials for ISOLDE radioactive waste anagement. The tool can also be used in the design of new RIB facilities, for licensing procedures, for irradiation experiments and the estimation of production yields.

  11. Isotopic evidence for biogenic molecular hydrogen production in the Atlantic Ocean

    NARCIS (Netherlands)

    Walter, S.; Kock, A.; Steinhoff, T.; Fiedler, B.; Fietzek, P.; Kaiser, J.; Krol, M.; Popa, M. E.; Chen, Q.; Tanhua, T.; Röckmann, T.

    2016-01-01

    Oceans are a net source of molecular hydrogen (H2) to the atmosphere. The production of marine H2 is assumed to be mainly biological by N2 fixation, but photochemical pathways are also discussed. We present measurements of mole fraction and isotopic composition of dissolved and atmospheric H2 from t

  12. Gold and isotopically enriched platinum targets for the production of radioactive beams of francium

    CERN Document Server

    Lipski, A R; Pearson, M R; Simsarian, J E; Sprouse, G D; Zhao, W Z

    1999-01-01

    Au and isotopically enriched Pt targets are discussed for the production of radioactive Fr beams. Target foils, serving also as ionizers, have to be heated in order to enhance the diffusion of atoms to the surface for further extraction and injection into the electrostatic transport system.

  13. Mass yield distributions of fission products from photo-fission of {sup 238}U induced by 11.5-17.3 MeV bremsstrahlung

    Energy Technology Data Exchange (ETDEWEB)

    Naik, H.; Goswami, A. [Bhabha Atomic Research Centre, Radiochemistry Division, Mumbai (India); Carrel, Frederick; Laine, Frederic; Sari, Adrien [SAPHIR Facility, Gif-sur-Yvette (France); Kim, G.N. [Kyungpook National University, Department of Physics, Daegu (Korea, Republic of); Normand, S. [Laboratory of Sensors and Elctronics Architectures CEA, Gif-sur-Yvette (France)

    2013-07-15

    The yields of various fission products in the 11.5, 13.4, 15.0 and 17.3 MeV bremsstrahlung-induced fission of {sup 238}U have been determined by recoil catcher and an off-line {gamma}-ray spectrometric technique using the electron linac, SAPHIR at CEA, Saclay, France. The mass yield distributions were obtained from the fission product yields using charge-distribution corrections. The peak-to-valley (P/V) ratio, average light mass (left angle A{sub L} right angle) and heavy mass (left angle A{sub H} right angle) and average number of neutrons (left angle v right angle) in the bremsstrahlung-induced fission of {sup 238}U at different excitation energies were obtained from the mass yield data. From the present and literature data in the {sup 238}U ({gamma}, f) and {sup 238}U (n, f) reactions at various energies, the following observations were obtained: i) The mass yield distributions in the {sup 238}U ({gamma}, f) reaction at various energies of the present work are double-humped, similar to those of the {sup 238}U (n, f) reaction of comparable excitation energy. ii) The yields of fission products for A = 133-134, A = 138-140, and A = 143-144 and their complementary products in the {sup 238}U ({gamma}, f) reaction are higher than other fission products due to the nuclear structure effect. iii) The yields of fission products for A = 133-134 and their complementary products are slightly higher in the {sup 238}U ({gamma}, f) than in the {sup 238}U (n, f), whereas for A = 138-140 and 143-144 and their complementary products are comparable. iv) With excitation energy, the increase of yields of symmetric products and the decrease of the peak-to-valley (P/V ratio in the {sup 238}U ({gamma}, f) reaction is similar to the {sup 238}U (n, f) reaction. v) The increase of left angle v right angle with excitation energy is also similar between the {sup 238}U ({gamma}, f) and {sup 238}U (n, f) reactions. However, it is surprising to see that the left angle A{sub L} right angle and

  14. Mass yield distributions of fission products from photo-fission of 238U induced by 11.5-17.3 MeV bremsstrahlung

    Science.gov (United States)

    Naik, H.; Carrel, Frédérick; Kim, G. N.; Laine, Frédéric; Sari, Adrien; Normand, S.; Goswami, A.

    2013-07-01

    The yields of various fission products in the 11.5, 13.4, 15.0 and 17.3 MeV bremsstrahlung-induced fission of 238U have been determined by recoil catcher and an off-line γ-ray spectrometric technique using the electron linac, SAPHIR at CEA, Saclay, France. The mass yield distributions were obtained from the fission product yields using charge-distribution corrections. The peak-to-valley ( P/ V ratio, average light mass () and heavy mass () and average number of neutrons () in the bremsstrahlung-induced fission of 238U at different excitation energies were obtained from the mass yield data. From the present and literature data in the 238U ( γ, f ) and 238U ( n, f ) reactions at various energies, the following observations were obtained: i) The mass yield distributions in the 238U ( γ, f ) reaction at various energies of the present work are double-humped, similar to those of the 238U ( n, f ) reaction of comparable excitation energy. ii) The yields of fission products for A = 133-134, A = 138-140, and A = 143-144 and their complementary products in the 238U ( γ, f) reaction are higher than other fission products due to the nuclear structure effect. iii) The yields of fission products for A = 133-134 and their complementary products are slightly higher in the 238U ( γ, f ) than in the 238U ( n, f ) , whereas for A = 138-140 and 143-144 and their complementary products are comparable. iv) With excitation energy, the increase of yields of symmetric products and the decrease of the peak-to-valley ( P/ V ratio in the 238U ( γ, f) reaction is similar to the 238U ( n, f) reaction. v) The increase of with excitation energy is also similar between the 238U ( γ, f ) and 238U ( n, f) reactions. However, it is surprising to see that the and values with excitation energy behave entirely differently from the 238U ( γ, f ) and 238U ( n, f ) reactions.

  15. The IMPELA TM 10 MeV, 50 kW electron linac: launching an industrial accelerator product

    Science.gov (United States)

    Stirling, Andrew J.

    1991-05-01

    In the previous conferences there has been no shortage of ideas, experiments and prototypes for industrial accelerators. Indeed, physicists propose new ideas at a rate faster than industry can get irradiators to the market. Certainly, the basic physics design must be sound, but this is a far from sufficient condition for an accelerator to succeed. Good physics design is needed to provide a good combination of electrical efficiency and useable power within the scan width. It may, however, be counterproductive if high performance compromises inherent reliability. From the engineering discipline is required an engineered control interface, an engineered product control and dosimetry system and traceable quality assurance. Just as important, the industrial client seeks an irradiator that is built quickly, and will be supported over a long service life (10-20 years). It is also necessary to assist the client in facility design, licencing and process verification. Providing these additional functions is a challenge for the business champions which equals what the technical champions face in obtaining full beam power.

  16. Lead contamination in cocoa and cocoa products: isotopic evidence of global contamination.

    Science.gov (United States)

    Rankin, Charley W; Nriagu, Jerome O; Aggarwal, Jugdeep K; Arowolo, Toyin A; Adebayo, Kola; Flegal, A Russell

    2005-10-01

    In this article we present lead concentrations and isotopic compositions from analyses of cocoa beans, their shells, and soils from six Nigerian cocoa farms, and analyses of manufactured cocoa and chocolate products. The average lead concentration of cocoa beans was cocoa and chocolate products were as high as 230 and 70 ng/g, respectively, which are consistent with market-basket surveys that have repeatedly listed lead concentrations in chocolate products among the highest reported for all foods. One source of contamination of the finished products is tentatively attributed to atmospheric emissions of leaded gasoline, which is still being used in Nigeria. Because of the high capacity of cocoa bean shells to adsorb lead, contamination from leaded gasoline emissions may occur during the fermentation and sun-drying of unshelled beans at cocoa farms. This mechanism is supported by similarities in lead isotopic compositions of cocoa bean shells from the different farms (206Pb/207Pb = 1.1548-1.1581; 208Pb/207Pb = 2.4344-2.4394) with those of finished cocoa products (206Pb/207Pb = 1.1475-1.1977; 208Pb/207Pb = 2.4234-2.4673). However, the much higher lead concentrations and larger variability in lead isotopic composition of finished cocoa products, which falls within the global range of industrial lead aerosols, indicate that most contamination occurs during shipping and/or processing of the cocoa beans and the manufacture of cocoa and chocolate products.

  17. Production of neutron-rich isotopes by one- and two-step processes in ISOL targets

    CERN Document Server

    Portillo, M; Gomes, I; Panteleev, V N; Fedorov, D V; Barzakh, A E; Beznosjuk, V I; Moroz, F V; Orlov, S Y; Volkov, Y M

    2002-01-01

    The results are presented for an experiment that compares the difference between a one- and two-step reaction setup using 1 GeV protons. The rates of production from an on-line isotope separator target containing UCx are measured for isotopes in the neutron mass region of Rb and Cs. Some details about the measured results and predictions by the Monte Carlo models are discussed. The effects of the delayed release on the extracted efficiency are generalized using analytical models for application to a wide range of nuclear decay lifetimes.

  18. The role of changing childhood diets in the prehistoric evolution of food production: An isotopic assessment.

    Science.gov (United States)

    Schurr, Mark R; Powell, Mary Lucas

    2005-03-01

    Earlier weaning has often been suggested as a cause for population growth after the evolution of food production. However, evidence for weaning-time reduction is largely circumstantial. Collagen stable nitrogen- and carbon-isotope ratios from juvenile and adult burials from four sites in eastern North America were measured to estimate weaning onsets and durations before and after the appearance of intensive food production. Two preagricultural Late Archaic sites (Indian Knoll and Carlston Annis) are compared with two highly agricultural Middle Mississippian sites (Angel and Tinsley Hill). Isotopic data and paleodemographic measures of birth rates provide no evidence for changes in weaning behavior or fertility with the development of food production in the prehistoric Lower Ohio Valley. Birth rates and weaning behavior appear to have been roughly the same at all four sites. These results indicate that models attributing population growth after the appearance of food production to earlier weaning are not universally applicable.

  19. Production cross sections of neutron rich isotopes from a 82Se beam

    CERN Document Server

    Tarasov, O B; Amthor, A M; Bandura, L; Baumann, T; Bazin, D; Berryman, J S; Chubarian, G; Fukuda, N; Gade, A; Ginter, T N; Hausmann, M; Inabe, N; Kubo, T; Pereira, J; Portillo, M; Sherrill, B M; Stolz, A; Sumithrarachchi, C; Thoennessen, M; Weisshaar, D

    2012-01-01

    Production cross sections for neutron-rich nuclei from the fragmentation of a 82Se beam at 139 MeV/u were measured. The longitudinal momentum distributions of 122 neutron-rich isotopes of elements $11 \\le Z \\le 32$ were determined by varying the target thickness. Production cross sections with beryllium and tungsten targets were determined for a large number of nuclei including several isotopes first observed in this work. These are the most neutron-rich nuclides of the elements $22 \\le Z \\le 25$ (64Ti, 67V, 69Cr, 72Mn). One event was registered consistent with 70Cr, and another one with 75Fe. A one-body Qg systematics is used to describe the production cross sections based on thermal evaporation from excited prefragments. The current results confirm those of our previous experiment with a 76Ge beam: enhanced production cross sections for neutron-rich fragments near Z=20.

  20. Consistent calculation of aquatic gross production from oxygen triple isotope measurements

    Directory of Open Access Journals (Sweden)

    J. Kaiser

    2011-04-01

    Full Text Available Oxygen triple isotope measurements can be used to calculate aquatic gross oxygen production rates. Past studies have emphasised the appropriate definition of the 17O excess and often used an approximation to derive production rates from the 17O excess. Here, I show that the calculation can be phrased more consistently and without any approximations using the relative 17O/16O and 18O/16O isotope ratio differences directly. The 17O excess is merely a mathematical construct and the derived production rate is independent of its definition, provided all calculations are performed with a consistent definition. I focus on the mixed layer, but also show how time series of triple oxygen measurements below the mixed layer can be used to derive gross production.

    In the calculation of mixed layer productivity, I explicitly include isotopic fractionation during gas invasion and evasion, which requires the oxygen supersaturation s to be measured as well. I also suggest how bubble injection could be considered in the same mathematical framework. I distinguish between concentration steady state and isotopic steady state and show that only the latter needs to be assumed in the calculation. It is even possible to derive an estimate of the net production rate in the mixed layer that is independent of the assumption of concentration steady state.

    I review measurements of the parameters required for the calculation of gross production rates and show how their systematic uncertainties as well as the use of different published calculation methods can cause large variations in the production rates for the same underlying isotope ratios. In particular, the 17O excess of dissolved O2 in equilibrium with atmospheric O2 and the 17O excess of photosynthetic O2 need to be re-measured. Because of these uncertainties, all

  1. Strontium Isotope Study of Coal Untilization By-products Interacting with Environmental Waters

    Energy Technology Data Exchange (ETDEWEB)

    Spivak-Birndorf, Lev J; Stewart, Brian W; Capo, Rosemary C; Chapman, Elizabeth C; Schroeder, Karl T; Brubaker, Tonya M

    2011-09-01

    Sequential leaching experiments on coal utilization by-products (CUB) were coupled with chemical and strontium (Sr) isotopic analyses to better understand the influence of coal type and combustion processes on CUB properties and the release of elements during interaction with environmental waters during disposal. Class C fly ash tended to release the highest quantity of minor and trace elements—including alkaline earth elements, sodium, chromium, copper, manganese, lead, titanium, and zinc—during sequential extraction, with bottom ash yielding the lowest. Strontium isotope ratios ({sup 87}Sr/{sup 86}Sr) in bulk-CUB samples (total dissolution of CUB) are generally higher in class F ash than in class C ash. Bulk-CUB ratios appear to be controlled by the geologic source of the mineral matter in the feed coal, and by Sr added during desulfurization treatments. Leachates of the CUB generally have Sr isotope ratios that are different than the bulk value, demonstrating that Sr was not isotopically homogenized during combustion. Variations in the Sr isotopic composition of CUB leachates were correlated with mobility of several major and trace elements; the data suggest that arsenic and lead are held in phases that contain the more radiogenic (high-{sup 87}Sr/{sup 86}Sr) component. A changing Sr isotope ratio of CUB-interacting waters in a disposal environment could forecast the release of certain strongly bound elements of environmental concern. This study lays the groundwork for the application of Sr isotopes as an environmental tracer for CUB–water interaction.

  2. Selective Gaseous Extraction: Research, Development and Training for Isotope Production, Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Bertch, Timothy C, [General Atomics

    2014-03-31

    General Atomics and the University of Missouri Research Reactor (MURR) completed research and development of selective gaseous extraction of fission products from irradiated fuel, which included training and education of MURR students. The process used porous fuel and after irradiation flowed product gases through the fuel to selectively removed desired fission products with the primary goal of demonstrating the removal of rhodium 105. High removal rates for the ruthenium/rhodium (Ru/Rh), tellurium/iodine (Te/I) and molybdenum/technetium (Mo/Tc) series were demonstrated. The success of this research provides for the reuse of the target for further production, significantly reducing the production of actinide wastes relative to processes that dissolve the target. This effort was conducted under DOE funding (DE-SC0007772). General Atomics objective of the project was to conduct R&D on alternative methods to produce a number of radioactive isotopes currently needed for medical and industry applications to include rhodium-105 and other useful isotopes. Selective gaseous extraction was shown to be effective at removing radioisotopes of the ruthenium/rhodium, tellurium/iodine and molybdenum/technetium decay chains while having trace to no quantities of other fission products or actinides. This adds a new, credible method to the area of certain commercial isotope production beyond current techniques, while providing significant potential reduction of process wastes. Waste reduction, along with reduced processing time/cost provides for superior economic feasibility which may allow domestic production under full cost recovery practices. This provides the potential for improved access to domestically produced isotopes for medical diagnostics and treatment at reduced cost, providing for the public good.

  3. Maximum reasonable radioxenon releases from medical isotope production facilities and their effect on monitoring nuclear explosions.

    Science.gov (United States)

    Bowyer, Theodore W; Kephart, Rosara; Eslinger, Paul W; Friese, Judah I; Miley, Harry S; Saey, Paul R J

    2013-01-01

    Fission gases such as (133)Xe are used extensively for monitoring the world for signs of nuclear testing in systems such as the International Monitoring System (IMS). These gases are also produced by nuclear reactors and by fission production of (99)Mo for medical use. Recently, medical isotope production facilities have been identified as the major contributor to the background of radioactive xenon isotopes (radioxenon) in the atmosphere (Stocki et al., 2005; Saey, 2009). These releases pose a potential future problem for monitoring nuclear explosions if not addressed. As a starting point, a maximum acceptable daily xenon emission rate was calculated, that is both scientifically defendable as not adversely affecting the IMS, but also consistent with what is possible to achieve in an operational environment. This study concludes that an emission of 5 × 10(9) Bq/day from a medical isotope production facility would be both an acceptable upper limit from the perspective of minimal impact to monitoring stations, but also appears to be an achievable limit for large isotope producers.

  4. Measurement of double differential cross sections for light charged particles production in neutron induced reaction at 62.7 MeV on lead target; Mesures des sections efficaces doublement differentielles de production de particules chargees legeres lors de reactions induites par neutrons de 62.7 MeV sur cible de plomb

    Energy Technology Data Exchange (ETDEWEB)

    Kerveno, M

    2000-09-27

    In order to develop new options for nuclear waste management, studies are carrying out on the perfecting of hybrid systems (sub-critical reactor driven by accelerator). This thesis work takes place more precisely in the framework of nuclear data linked to hybrid systems development. Increasing the upper limit energy value (from 20 to 150 MeV) of data bases supposes that theoretical codes could have sufficient predictive power in this energy range. Thus it's necessary to measure new cross sections to constrain these codes. The experiment, performed at Louvain-la-Neuve Cyclotron, aims to determine the double differential cross sections for light charged particles production in neutron induced reactions at 62.7 MeV on natural lead target. The detection device consists of 6 NE102-CsI telescopes. Time of flight measurements are used to reconstruct the neutron energy spectra. The general framework (hybrid systems and associated nuclear data problematic) in which this work takes place is presented in a first part. The experimental set up used for our measurements is described in a second part. The three following parts are dedicated to the data analysis and double differential cross sections extraction. The particle discrimination, the energy calibration of detectors as the different corrections applied to the experimental spectra are related in details. And finally a comparative study between our experimental results and some theoretical predictions is presented. (author)

  5. Fission product yield distribution in the 12, 14, and 16 MeV bremsstrahlung-induced fission of {sup 232}Th

    Energy Technology Data Exchange (ETDEWEB)

    Naik, H. [Bhabha Atomic Research Centre, Radiochemistry Division, Mumbai (India); Kyungpook National University, Department of Physics and Center for High Energy Physics, Daegu (Korea, Republic of); Kim, G.N.; Kim, K. [Kyungpook National University, Department of Physics and Center for High Energy Physics, Daegu (Korea, Republic of); Schwengner, R.; John, R.; Massarczyk, R.; Junghans, A.; Wagner, A. [Helmholtz-Zentrum Dresden-Rossendorf, Dresden (Germany); Goswami, A. [Bhabha Atomic Research Centre, Radiochemistry Division, Mumbai (India)

    2015-11-15

    The absolute cumulative yields of various fission products in the 12, 14, and 16 MeV bremsstrahlung-induced fission of {sup 232}Th were determined using a recoil catcher and an off-line γ -ray spectrometric technique using the ELBE electron linac of Helmholtz-Zentrum Dresden-Rossendorf in Dresden, Germany. The mass chain yields were obtained from the absolute cumulative yields by correcting the charge distribution. The peak-to-valley ratio, average light mass (left angle A{sub L} right angle) and heavy mass (left angle A{sub H} right angle) values, and average number of neutrons (left angle n right angle {sub exp}) in the bremsstrahlung-induced fission of {sup 232}Th at different excitation energies were obtained from the mass chain yield data. The present study and existing literature data for the {sup 232}Th(γ, f) reaction are compared with similar data for the {sup 238}U(γ, f) reaction at various excitation energies, and surprisingly different behavior was found in the two fissioning systems. (orig.)

  6. Radioactive isotope production for medical applications using Kharkov electron driven subcritical assembly facility.

    Energy Technology Data Exchange (ETDEWEB)

    Talamo, A.; Gohar, Y.; Nuclear Engineering Division

    2007-05-15

    Kharkov Institute of Physics and Technology (KIPT) of Ukraine has a plan to construct an accelerator driven subcritical assembly. The main functions of the subcritical assembly are the medical isotope production, neutron thereby, and the support of the Ukraine nuclear industry. Reactor physics experiments and material research will be carried out using the capabilities of this facility. The United States of America and Ukraine have started collaboration activity for developing a conceptual design for this facility with low enrichment uranium (LEU) fuel. Different conceptual designs are being developed based on the facility mission and the engineering requirements including nuclear physics, neutronics, heat transfer, thermal hydraulics, structure, and material issues. Different fuel designs with LEU and reflector materials are considered in the design process. Safety, reliability, and environmental considerations are included in the facility conceptual design. The facility is configured to accommodate future design improvements and upgrades. This report is a part of the Argonne National Laboratory Activity within this collaboration for developing and characterizing the subcritical assembly conceptual design. In this study, the medical isotope production function of the Kharkov facility is defined. First, a review was carried out to identify the medical isotopes and its medical use. Then a preliminary assessment was performed without including the self-shielding effect of the irradiated samples. Finally, more detailed investigation was carried out including the self-shielding effect, which defined the sample size and irradiation location for producing each medical isotope. In the first part, the reaction rates were calculated as the multiplication of the cross section with the unperturbed neutron flux of the facility. Over fifty isotopes were considered and all transmutation channels are used including (n,{gamma}), (n,2n), (n,p), and ({gamma},n). In the second part

  7. Neutron-rich isotope production using a uranium carbide - carbon nanotubes SPES target prototype

    Science.gov (United States)

    Corradetti, S.; Biasetto, L.; Manzolaro, M.; Scarpa, D.; Carturan, S.; Andrighetto, A.; Prete, G.; Vasquez, J.; Zanonato, P.; Colombo, P.; Jost, C. U.; Stracener, D. W.

    2013-05-01

    The SPES (Selective Production of Exotic Species) project, under development at the Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali di Legnaro (INFN-LNL), is a new-generation Isotope Separation On-Line (ISOL) facility for the production of radioactive ion beams by means of the proton-induced fission of uranium. In the framework of the research on the SPES target, seven uranium carbide discs, obtained by reacting uranium oxide with graphite and carbon nanotubes, were irradiated with protons at the Holifield Radioactive Ion Beam Facility (HRIBF) of Oak Ridge National Laboratory (ORNL). In the following, the yields of several fission products obtained during the experiment are presented and discussed. The experimental results are then compared to those obtained using a standard uranium carbide target. The reported data highlights the capability of the new type of SPES target to produce and release isotopes of interest for the nuclear physics community.

  8. The production of proton-rich isotopes beyond iron: The $\\gamma$ process in stars

    CERN Document Server

    Pignatari, Marco; Reifarth, René; Travaglio, Claudia

    2016-01-01

    Beyond iron, a small fraction of the total abundances in the Solar System is made of proton-rich isotopes, the p nuclei. The clear understanding of their production is a fundamental challenge for nuclear astrophysics. The p nuclei constrain the nucleosynthesis in core-collapse and thermonuclear supernovae. The $\\gamma$ process is the most established scenario for the production of the p nuclei, which are produced via different photodisintegration paths starting on heavier nuclei. A large effort from nuclear physics is needed to access the relevant nuclear reaction rates far from the valley of stability. This review describes the production of the heavy proton-rich isotopes by the $\\gamma$ process in stars, and explores the state of the art of experimental nuclear physics to provide nuclear data for stellar nucleosynthesis.

  9. High brightness 50 MeV Cyclotron for Accelerator-Driven Subcritical Fission

    Science.gov (United States)

    Assadi, Saeed; Badgley, Karie; Mann, Thomas; McIntyre, Peter; Pogue, Nathaniel; Sattarov, Akhdiyor

    2011-10-01

    The Accelerator Research Lab at Texas A&M University is developing new accelerator technology for a high-brightness, high-current cyclotron with capabilities that will be beneficial for applications to accelerator-driven subcritical fission, medical isotope production, and proton therapy. As a first embodiment of the technology, we are developing a detailed design for TAMU-50, a 50 MeV, 5 mA proton cyclotron with high beam brightness. In this presentation we present devices and beamline components for injection, extraction, controls and diagnostics. We emphasize the system integration and implementation of TAMU-50 for production of medical radioisotopes.

  10. Neutron-induced fission cross sections of 233U and 243Am in the energy range 0.5 Mev En 20 MeV @ n_TOF

    CERN Document Server

    Belloni, F; Milazzo, P M; Calviani, M; Colonna, N; Mastinu, P; Abbondanno, U; Aerts, G; Álvarez, H; Álvarez-Velarde, F; Andriamonje, S; Andrzejewski, J; Assimakopoulos, P; Audouin, L; Badurek, G; Baumann, P; Becvár, F; Berthoumieux, E; Calviño, F; Cano-Ott, D; Capote, R; Carrapiço, C; Cennini, P; Chepel, V; Chiaveri, E; Cortes, G; Couture, A; Cox, J; Dahlfors, M; David, S; Dillmann, I; Domingo-Pardo, C; Dridi, W; Duran, I; Eleftheriadis, C; Embid-Segura, M; Ferrant, L; Ferrari, A; Ferreira-Marques, R; Fujii, K; Furman, W; Goncalves, I; González-Romero, E; Gramegna, F; Guerrero, C; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martinez, A; Igashira, M; Jericha, E; Käppeler, F; Kadi, Y; Karadimos, D; Karamanis, D; Kerveno, M; Koehler, P; Kossionides, E; Krticka, M; Lampoudis, C; Leeb, H; Lindote, A; Lopes, I; Lozano, M; Lukic, S; Marganiec, J; Marrone, S; Martínez, T; Massimi, C; Mengoni, A; Moreau, C; Mosconi, M; Neves, F; Oberhummer, H; O'Brien, S; Pancin, J; Papachristodoulou, C; Papadopoulos, C; Paradela, C; Patronis, N; Pavlik, A; Pavlopoulos, P; Perrot, L; Pigni, M T; Plag, R; Plompen, A; Plukis, A; Poch, A; Praena, J; Pretel, C; Quesada, J; Rauscher, T; Reifarth, R; Rubbia, C; Rudolf, G; Rullhusen, P; Salgado, J; Santos, C; Sarchiapone, L; Savvidis, I; Stephan, C; Tagliente, G; Tain, J L; Tassan-Got, L; Tavora, L; Terlizzi, R; Vannini, G; Vazl, P; Ventura, A; Villamarin, D; Vincente, M C; Vlachoudis, V; Vlastou, R; Voss, F; Walter, S; Wiescher, M; Wisshak, K

    2011-01-01

    Neutron-induced fission cross-sections of actinides have been recently measured at the neutron time of flight facility n_TOF at CERN in the frame of a research project involving isotopes relevant for nuclear astrophysics and nuclear technologies. Fission fragments are detected by a gas counter with good discrimination between nuclear fission products and background events. Neutron-induced fission cross-sections of 233U and 243Am were determined relative to 235U. The present paper reports the results obtained at neutron energies between 0.5 and 20 MeV.

  11. Consistency of neutron cross-section data, S /SUB N/ calculations, and measured tritium production for a 14-MeV neutron-driven sphere of natural lithium deuteride

    Energy Technology Data Exchange (ETDEWEB)

    Reupke, W.A.; Davidson, J.N.; Muir, D.W.

    1982-12-01

    The authors present algorithms, describe a computer program, and gives a computational procedure for the statistical consistency analysis of neutron cross-section data, S /SUB N/ calculations, and measured tritium production in 14-MeV neutron-driven integral assemblies. Algorithms presented include a reduced matrix manipulation technique suitable for manygroup, 14-MeV neutron transport calculations. The computer program incorporates these algorithms and is expanded and improved to facilitate analysis of such integral experiments. Details of the computational procedure are given for a natural lithium deuteride experiment performed at the Los Alamos National Laboratory. Results are explained in terms of calculated cross-section sensitivities and uncertainty estimates. They include a downward adjustment of the /sup 7/Li(n,xt) 14-MeV cross section from 328 + or - 22 to 284 + or - 24 mb, which is supported by the trend of recent differential and integral measurements. It is concluded that with appropriate refinements, the techniques of consistency analysis can be usefully applied to the analysis of 14-MeV neutron-driven tritium production integral experiments.

  12. Molybdenum-99 Isotope Production Preparation at Sandia National Laboratories

    Energy Technology Data Exchange (ETDEWEB)

    Carson, S.D.; Longley, S.W.; McDonald, M.J.; Parma, E.J.; Vernon, M.E.

    1998-10-07

    `Q&c M. J. McDonald, S. D. Carson, S. W. Longley, E. J. Parma, M. E. Vern `~ I@ .,., Sandia National Laboratories*, P. .0. Box 5800, Albuquerque, NM, 8 W? 1$ tl?;:q `f. (3 . 8 /'~ Abstract This report was prepared as an account of work sponsored byanagency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. loading on the Cintichem targets. These tests were designed to gain process knowledge prior to processing an irradiated target. The chemical separation tests were performed in a fime hood During cold testing, several tests were performed on individual components of the process to complete, a series of `hot' tests was designed to process irradiated targets. These were designed to optimize the process, identify problems prior to processing higher inventory targets, and to the shielded containment box (SCB). Table 1 is a summary of the tests performed prior to the Test Target Power Post irradiation Total inventory 99M0 inventory (kW)/ Irradiation decay (hrs) (TBq*) /decay (TBq)/decay Time (hrs) inventory (TBq) inventory(TBq) in the processing boxes as color comparisons. Product quality control testing was conducted for all the tests and the results were compared to The production process generates a high activity

  13. Praseodymium activation detector for measuring bursts of 14 MeV neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Meehan, Tim, E-mail: meehanbt@nv.doe.go [National Security Technologies, LLC, P.O. Box 98521, North Las Vegas, NV 89030 (United States); Hagen, E.C. [National Security Technologies, LLC, P.O. Box 98521, North Las Vegas, NV 89030 (United States); Ruiz, C.L.; Cooper, G.W. [Sandia National Laboratories, P.O. Box 5800, Albuquerque, NM 87185 (United States)

    2010-08-21

    A new, accurate, neutron activation detection scheme for measuring pulsed neutrons has been designed and tested. The detection system is sensitive to neutrons with energies above 10 MeV; importantly, it is insensitive to gamma radiation <10 MeV and to lower-energy (e.g., fission and thermal) neutrons. It is based upon the use of {sup 141}Pr, an element that has a single, naturally occurring isotope, a significant n,2n cross-section, and decays by positron emission that result in two coincident 511 keV photons. Neutron fluences are thus inferred by relating measured reaction product decay activity to fluence. Specific sample activity is measured using the sum-peak method to count gamma-ray coincidences from the annihilation of the positron decay products. The system was tested using 14 and 2.45 MeV neutron bursts produced by NSTec Dense Plasma Focus Laboratory fusion sources. Lead, copper, beryllium, and silver activation detectors were compared. The detection method allows measurement of 14 MeV neutron yield with a total error of {approx}18%.

  14. Isotopic signatures of production and uptake of H2 by soil

    Directory of Open Access Journals (Sweden)

    Q. Chen

    2015-09-01

    Full Text Available Molecular hydrogen (H2 is the second most abundant reduced trace gas (after methane in the atmosphere, but its biogeochemical cycle is not well understood. Our study focuses on the soil production and uptake of H2 and the associated isotope effects. Air samples from a grass field and a forest site in the Netherlands were collected using soil chambers. The results show that uptake and emission of H2 occurred simultaneously at all sampling sites, with strongest emission at the grassland sites where clover (N2 fixing legume was present. The H2 mole fraction and deuterium content were measured in the laboratory to determine the isotopic fractionation factor during H2 soil uptake (αsoil and the isotopic signature of H2 that is simultaneously emitted from the soil (δDsoil. By considering all net-uptake experiments, an overall fractionation factor for deposition of αsoil = kHD/kHH = 0.945 ± 0.004 (95 % CI was obtained. The difference in mean αsoil between the forest soil 0.937 ± 0.008 and the grassland 0.951 ± 0.025 is not statistically significant. For two experiments, the removal of soil cover increased the deposition velocity (vd and αsoil simultaneously, but a general positive correlation between vd and αsoil was not found in this study. When the data are evaluated with a model of simultaneous production and uptake, the isotopic composition of H2 that is emitted at the grassland site is calculated as δDsoil = (−530 ± 40 ‰. This is less deuterium-depleted than what is expected from isotope equilibrium between H2O and H2.

  15. Excitation functions of residual nuclei production from 40–2600 MeV proton-irradiated 206,207,208,natPb and 209Bi

    Indian Academy of Sciences (India)

    Yu E Titarenko; V F Batyaev; V M Zhivun; V O Kudryashov; K A Lipatov; A V Ignatyuk; S G Mashnik

    2007-02-01

    The work is aimed at experimental determination of the independent and cumulative yields of radioactive residual nuclei produced in intermediate-energy proton-irradiated thin targets made of highly isotopic enriched and natural lead (206,207,208,natPb) and 209Bi. 5972 radioactive product nuclide yields have been measured in 55 thin targets induced by 0.04, 0.07, 0.10, 0.15, 0.25, 0.6, 0.8, 1.2, 1.4, 1.6 and 2.6 GeV protons extracted from the ITEP U-10 proton synchrotron. The measured data have been compared with data obtained at other laboratories as well as with theoretical simulations by seven codes. We found that the predictive power of the tested codes is different but is satisfactory for most of the nuclides in the spallation region, though none of the codes agree well with the data in the whole mass region of product nuclides and all should be improved further.

  16. Recent progress of in-flight separators and rare isotope beam production

    Energy Technology Data Exchange (ETDEWEB)

    Kubo, Toshiyuki, E-mail: kubo@ribf.riken.jp

    2016-06-01

    New-generation in-flight separators are being developed worldwide, including the Super-FRS separator at the GSI Facility for Antiproton and Ion Research (FAIR), the ARIS separator at the Michigan State University (MSU) Facility for Rare Isotopes Beams (FRIB), and the BigRIPS separator at the RIKEN RI Beam Factory (RIBF), each of which is aimed at expanding the frontiers of rare isotope (RI) production and advancing experimental studies on exotic nuclei far from stability. Here, the recent progress of in-flight separators is reviewed, focusing on the advanced features of these three representative separators. The RI beam production that we have conducted using the BigRIPS separator at RIKEN RIBF is also outlined.

  17. Cadmium-isotopic evidence for increasing primary productivity during the Late Permian anoxic event

    Science.gov (United States)

    Georgiev, Svetoslav V.; Horner, Tristan J.; Stein, Holly J.; Hannah, Judith L.; Bingen, Bernard; Rehkämper, Mark

    2015-01-01

    Earth's most extreme extinction event near the end of the Late Permian decimated more than 90% of all extant marine species. Widespread and intensive oceanic anoxia almost certainly contributed to the catastrophe, though the driving mechanisms that sustained such conditions are still debated. Of particular interest is whether water column anoxia was a consequence of a 'stagnant ocean', or if it was controlled by increases in nutrient supply, primary productivity, and subsequent heterotrophic respiration. Testing these competing hypotheses requires deconvolving sedimentary/bottom water redox conditions from changes in surface water productivity in marine sediments. We address this issue by studying marine shales from East Greenland and the mid-Norwegian shelf and combining sedimentary redox proxies with cadmium-isotopic analyses. Sedimentary nitrogen-isotopic data, pyrite framboid analyses, and organic and inorganic shale geochemistry reveal sulfidic conditions with vigorous upwelling, and increasingly anoxic conditions with a strengthening upwelling in the Greenland and Norwegian sections, respectively. Detailed analysis of sedimentary metal budgets illustrates that Cd is primarily associated with organic carbon and records primary geochemical signatures, thus enabling reconstruction of surface water nutrient utilization. Cadmium-isotopic analyses of the authigenic shale fraction released by inverse aqua regia digestion yield an average δ114Cd110 of + 0.15 ± 0.01 ‰ (2 SE, n = 12; rel. NIST SRM 3108), indicative of incomplete surface water nutrient utilization up-section. The constant degree of nutrient utilization combined with strong upwelling requires increasing primary productivity - and not oceanic stagnation - to balance the larger nutrient fluxes to both study sites during the development of the Late Permian water column anoxia. Overall, our data illustrate that if bottom water redox and upwelling can be adequately constrained, Cd-isotopic analyses of

  18. Multi-isotopic signatures of organic and conventional Italian pasta along the production chain

    DEFF Research Database (Denmark)

    Bontempo, L.; Camin, F.; Paolini, M.

    2016-01-01

    The variability of stable isotope ratios (δ2H, δ13C, δ15N, δ18O and δ34S) along the production chain of pasta (durum wheat, flour and pasta) produced by using both conventional and organic farming systems in four Italian regions in 2 years was investigated. The aim was to evaluate if and how...... control procedures that can be used to check the geographical origin of Italian organic and conventional pasta and its raw materials....

  19. Fractionation of Mercury Stable Isotopes during Microbial Methylmercury Production by Iron- and Sulfate-Reducing Bacteria.

    Science.gov (United States)

    Janssen, Sarah E; Schaefer, Jeffra K; Barkay, Tamar; Reinfelder, John R

    2016-08-01

    The biological production of monomethylmercury (MeHg) in soils and sediments is an important factor controlling mercury (Hg) accumulation in aquatic and terrestrial food webs. In this study we examined the fractionation of Hg stable isotopes during Hg methylation in nongrowing cultures of the anaerobic bacteria Geobacter sulfurreducens PCA and Desulfovibrio desulfuricans ND132. Both organisms showed mass-dependent, but no mass-independent fractionation of Hg stable isotopes during Hg methylation. Despite differences in methylation rates, the two bacteria had similar Hg fractionation factors (αr/p = 1.0009 and 1.0011, respectively). Unexpectedly, δ(202)Hg values of MeHg for both organisms were 0.4‰ higher than the value of initial inorganic Hg after about 35% of inorganic Hg had been methylated. These results indicate that a (202)Hg-enriched pool of inorganic Hg was preferentially utilized as a substrate for methylation by these organisms, but that multiple intra- and/or extracellular pools supplied inorganic Hg for biological methylation. Understanding the controls of the Hg stable isotopic composition of microbially produced MeHg is important to identifying bioavailable Hg in natural systems and the interpretation of Hg stable isotopes in aquatic food webs.

  20. Investigation of two technical toxaphene products by using isotope ratio mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Vetter, W.; Armbruster, W. [Hohenheim Univ., Stuttgart (Germany). Inst. fuer Lebensmittelchemie; Gleixner, G. [Max-Planck-Institut fuer Biogeochemie, Jena (Germany)

    2004-09-15

    Organochlorine compounds have been used in high quantities throughout the past 60 years. Being long-lived in the environment and toxic to humans and wildlife, some of them were classified as persistent organic pollutants (POPs). One of the POPs of special concern is toxaphene which is produced by the chlorination of the natural product camphene (or {alpha}-pinene). The technical products consist of several hundred compounds, mainly of chlorobornanes with an average number of eight chlorine substituents. Toxaphene has been produced in high quantities in different parts of the world. Even though the use has been discontinued during the last two decades, there are still several ecosystems which are heavily contaminated with this chloropesticide. Due to the huge variety of the technical products accompanied with a severe change of composition in the environment, analytical tracing back of toxaphene residues to a specific product has not yet been achieved. One of the potential analytical tools for distinguishing substances that differ only in their way of production is the determination of ratios of stable isotopes ({sup 13}C/{sup 12}C; {sup 2}H/{sup 1}H; {sup 15}N/{sup 14}N). Since the synthesis of toxaphene is starting from natural compounds obtained from different continents, the technical products could have different ratios of stable isotopes. In this study, we investigated the {sup 13}C/{sup 12}C ratio of two former major toxaphene products.

  1. Study of the Production of Radioactive Isotopes through Cosmic Muon Spallation in KamLAND

    Energy Technology Data Exchange (ETDEWEB)

    KamLAND Collaboration; Abe, S.; Enomoto, S.; Furuno, K.; Gando, Y.; Ikeda, H.; Inoue, K.; Kibe, Y.; Kishimoto, Y.; Koga, M.; Minekawa, Y.; Mitsui, T.; Nakajima, K.; Nakajima, K.; Nakamura, K.; Nakamura, M.; Shimizu, I.; Shimizu, Y.; Shirai, J.; Suekane, F.; Suzuki, A.; Takemoto, Y.; Tamae, K.; Terashima, A.; Watanabe, H.; Yonezawa, E.; Yoshida, S.; Kozlov, A.; Murayama, H.; Busenitz, J.; Classen, T.; Grant, C.; Keefer, G.; Leonard, D. S.; McKee, D.; Piepke, A.; Banks, T. I.; Bloxham, T.; Detwiler, J. A.; Freedman, S. J.; Fujikawa, B. K.; Gray, F.; Guardincerri, E.; Hsu, L.; Ichimura, K.; Kadel, R.; Lendvai, C.; Luk, K.-B.; O' Donnell, T.; Steiner, H. M.; Winslow, L. A.; Dwyer, D. A.; Jillings, C.; Mauger, C.; McKeown, R. D.; Vogel, P.; Zhang, C.; Berger, B. E.; Lane, C. E.; Maricic, J.; Miletic, T.; Batygov, M.; Learned, J. G.; Matsuno, S.; Pakvasa, S.; Foster, J.; Horton-Smith, G. A.; Tang, A.; Dazeley, S.; Downum, K. E.; Gratta, G.; Tolich, K.; Bugg, W.; Efremenko, Y.; Kamyshkov, Y.; Perevozchikov, O.; Karwowski, H. J.; Markoff, D. M.; Tornow, W.; Heeger, K. M.; Piquemal, F.; Ricol, J.-S.; Decowski, M. P.

    2009-06-30

    Radioactive isotopes produced through cosmic muon spallation are a background for rare event detection in {nu} detectors, double-beta-decay experiments, and dark-matter searches. Understanding the nature of cosmogenic backgrounds is particularly important for future experiments aiming to determine the pep and CNO solar neutrino fluxes, for which the background is dominated by the spallation production of {sup 11}C. Data from the Kamioka Liquid scintillator Anti-Neutrino Detector (KamLAND) provides valuable information for better understanding these backgrounds, especially in liquid scintillator, and for checking estimates from current simulations based upon MUSIC, FLUKA, and Geant4. Using the time correlation between detected muons and neutron captures, the neutron production yield in the KamLAND liquid scintillator is measured to be (2.8 {+-} 0.3) x 10{sup -4} n/({mu} {center_dot} (g/cm{sup 2})). For other isotopes, the production yield is determined from the observed time correlation related to known isotope lifetimes. We find some yields are inconsistent with extrapolations based on an accelerator muon beam experiment.

  2. Identification of sources and production processes of bottled waters by stable hydrogen and oxygen isotope ratios.

    Science.gov (United States)

    Brencic, Mihael; Vreca, Polona

    2006-01-01

    Bottled water is a food product that considerably depends on the environment from which it originates, not only at the place where it is produced, but predominantly on the conditions in the recharge area of the wells captured for bottling. According to their source and the bottling process, bottled waters can be divided into natural and artificially sparkling waters, still and flavoured waters. These waters originate from various parts of the hydrological cycle and their natural origin is reflected in their hydrogen and oxygen stable isotopic compositions (delta(2)H and delta(18)O). A total of 58 domestic and foreign brands and 16 replicates of bottled waters, randomly collected on the Slovene market in September 2004, were analysed for delta(2)H and delta(18)O. The isotopic composition varied between -83 per thousand and -46 per thousand with an average of -66 per thousand for hydrogen, and between -11.9 per thousand and -7.5 per thousand with an average of -9.6 per thousand for oxygen. This investigation helped (1) to determine and test the classification of bottled waters, (2) to determine the natural origin of bottled water, and (3) to indicate differences between the natural and production processes. The production process may influence the isotopic composition of flavoured waters and artificially sparkling waters. No such modification was observed for still and natural sparkling waters. The methods applied, together with hydrological knowledge, can be used for the authentication of bottled waters for regulatory and consumer control applications.

  3. Potential methane production rates and its carbon isotopic composition from ornithogenic tundra soils in coastal Antarctic

    Institute of Scientific and Technical Information of China (English)

    BAO Tao; ZHU Renbin; BAI Bo; XU Hua

    2016-01-01

    Methane (CH4) is one of important greenhouse gases with chemical activity. The determination of isotopic compositions for CH4 emitted from the soils helps us to understand its production mechanisms. CH4 isotope measurements have been conducted for different types of global terrestrial ecosystems. However, no isotopic data of CH4 have been reported from Antarctic tundra soils. In this paper, ornithogenic soil profiles were collected from four penguin colonies, and potential CH4 production rates and its13C ratio (δ13C) were investigated based upon laboratory incubation experiments. The mean CH4 production rates are highly variable in these soil proifles, ranging from 0.7 to 20.3 μg CH4−C kg−1∙h−1. These ornithogenic soils had high potential production rates of CH4 under ambient air incubation or under N2 incubation, indicating the importance of potential CH4 emissions from penguin colonies. Most of the soil samples had higher δ13C-CH4 under N2 incubation (−39.28%~−43.53%) than under the ambient air incubation (−42.81%~−57.19%). Highly anaerobic conditions were conducive to the production of CH4 enriched in13C, and acetic acid reduction under N2 incubation might be a predominant source for soil CH4production. Overall theδ13C-CH4 showed a signiifcant negative correlation with CH4 production rates in ornithogenic tundra soils under N2 incubation (R2=0.41,p<0.01) or under the ambient air incubation (R2=0.50,p<0.01). Potential CH4 production from ornithogenic soils showed a signiifcant positive correlation with total phosphorus (TP) and NH4+−N contents, pH and soil moisture (Mc), but the δ13C-CH4 showed a signiifcant negative correlation with TP and NH4+−N contents, pH and Mc, indicating that the deposition amount of penguin guano increased potential CH4 production rates from tundra soils, but decreased the δ13C-CH4. The CH4 emissions from the ornithogenic soils affect carbon isotopic compositions of atmospheric CH4in coastal Antarctica.

  4. Excitation functions for the production of radionuclides by neutron-induced reactions on C, O, Mg, Al, Si, Fe, Co, Ni, Cu, Ag, Te, Pb, and U up to 180 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Michel, R., E-mail: michel@irs.uni-hannover.de [Institute for Radioecology and Radiological Protection, Leibniz University Hannover (Germany); Hansmann, D. [Institute for Radioecology and Radiological Protection, Leibniz University Hannover (Germany); Neumann, S. [Institute for Radioecology and Radiological Protection, Leibniz University Hannover (Germany); Physikalisch-Technische Bundesanstalt (PTB), Braunschweig (Germany); Glasser, W. [Institute for Radioecology and Radiological Protection, Leibniz University Hannover (Germany); Schuhmacher, H.; Dangendorf, V.; Nolte, R. [Physikalisch-Technische Bundesanstalt (PTB), Braunschweig (Germany); Herpers, U. [Dept. for Nuclear Chemistry, University of Cologne (Germany); Smirnov, A.N.; Ryzhov, I.V. [V. G. Khlopin Radium Institute, St. Petersburg (Russian Federation); Prokofiev, A.V. [The Svedberg Laboratory (TSL), Uppsala University (Sweden); Dept. of Physics and Astronomy, Uppsala University (Sweden); Malmborg, P. [The Svedberg Laboratory (TSL), Uppsala University (Sweden); Kollár, D. [Dept. of Nuclear Physics, Comenius University, Bratislava (Slovakia); Meulders, J.-P. [Université Catholique de Louvain (UCL), Louvain-la-Neuve (Belgium)

    2015-01-15

    Irradiation experiments with well-characterized, quasi mono-energetic neutrons of energies between 32.7 MeV and 175.4 MeV were performed at UCL/Louvain-la-Neuve and TSL/Uppsala. The abundances of relatively short-lived residual radionuclides from 13 different target elements were determined by γ-spectrometry. More than 100 excitation functions of neutron-induced reactions were unfolded based on the neutron spectra and the radionuclide abundances with the aid of additional information that was provided by “guess” excitation functions calculated by the TALYS 1.0 code. The results are compared with the sparse existing data from other authors. The new excitation functions were validated by calculation of and comparison with experimental thick-target production rates. Consistency with neutron excitation functions up to 1.6 GeV, which were derived earlier by unfolding the thick-target production rates, was so demonstrated.

  5. Oxidation Products of Ester-Based Oils with and without Antioxidants Identified by Stable Isotope Labelling and Mass Spectrometry

    National Research Council Canada - National Science Library

    Marcella Frauscher; Charlotte Besser; Günter Allmaier; Nicole Dörr

    2017-01-01

    ... is of high importance. In order to reveal their degradation products and processes, a novel approach combining artificial alteration, isotope labelling based on oxidation with 16O2 and 18O2, and mass spectrometry (MS...

  6. Using Carbon Isotopes in Cenozoic Soil Carbonates to Quantify Primary Productivity from Mid-Latitude Regions

    Science.gov (United States)

    Caves, J. K.; Kramer, S. H.; Ibarra, D. E.; Chamberlain, C. P.

    2015-12-01

    The carbon isotope composition of pedogenic carbonates (δ13Ccarb) from paleosols has been extensively used as a proxy to estimate atmospheric pCO2 over the Phanerozoic. However, a number of other factors - including the concentration of plant-respired CO2 and the isotopic composition of both atmospheric and plant-respired carbon - influence the δ13C of pedogenic carbonates. For example, δ13Ccarb records from the mid-latitudes in central Asia and western North America show increasing trends in δ13Ccarb despite decreasing pCO2 during the late Cenozoic, which suggests that other factors play an important role in determining the isotopic composition of pedogenic carbonates. Instead, we suggest that these records are primarily recording changes in primary productivity rather than changes in atmospheric pCO2 and therefore propose a novel use of paleosol carbonate records to understand paleo-ecosystem dynamics. Here, we compile existing paleosol carbonate records, and present three new records from Wyoming, to estimate soil respiration and primary productivity in western North America during the Paleogene and early Neogene. We observe both an overall increase in δ13Ccarb after the early Eocene, and spatially heterogeneous δ13Ccarb values across western US basins. We combine this δ13Ccarb data with compilations of atmospheric pCO2 to estimate soil respiration and plant productivity. The long-term increase in δ13Ccarb indicates a decrease in plant productivity as conditions became more arid across much of the western US, congruent with both records of regional uplift and of global cooling. Furthermore, significant spatial heterogeneity in δ13Ccarb indicates that regional factors, such as the presence of paleolakes and/or local paleotopography may have provided a second-order control on local and regional productivity. Thus, our results provide a first-order estimate linking changes in primary productivity with regional tectonics and global climatic change.

  7. First intense isotopic titanium-50 beam using MIVOC method

    Energy Technology Data Exchange (ETDEWEB)

    Rubert, J.; Piot, J. [Departement de Recherches Subatomiques, Institut Pluridisciplinaire Hubert Curien, UMR 7178, Universite de Strasbourg/CNRS-IN-2P-3, 23 rue du Loess, F-67037 Strasbourg (France); Asfari, Z. [Laboratoire d' Ingenierie Moleculaire Appliquee a l' Analyse (DSA), Institut Pluridisciplinaire Hubert Curien, UMR 7178, Universite de Strasbourg/CNRS-IN-2P-3, 23 rue du Loess, F-67037 Strasbourg (France); Gall, B.JP., E-mail: benoit.gall@iphc.cnrs.fr [Departement de Recherches Subatomiques, Institut Pluridisciplinaire Hubert Curien, UMR 7178, Universite de Strasbourg/CNRS-IN-2P-3, 23 rue du Loess, F-67037 Strasbourg (France); Aerje, J. [Department of Physics, University of Jyvaeskylae, P.O. Box 35 (YFL), Jyvaeskylae FI-40014 (Finland); Dorvaux, O. [Departement de Recherches Subatomiques, Institut Pluridisciplinaire Hubert Curien, UMR 7178, Universite de Strasbourg/CNRS-IN-2P-3, 23 rue du Loess, F-67037 Strasbourg (France); Greenlees, P.T.; Koivisto, H. [Department of Physics, University of Jyvaeskylae, P.O. Box 35 (YFL), Jyvaeskylae FI-40014 (Finland); and others

    2012-04-01

    An organometallic compound isotopically enriched in titanium-50 has been successfully used for the first time to produce intense ion beams with an ECR ion source by means of the MIVOC method. After some fruitful tests performed with compounds produced at IPHC Strasbourg with natural titanium, enriched organometallic titanium compound was produced successfully, beam extracted from ECR ion sources and accelerated through a K = 130 MeV cyclotron to an energy of 242 MeV. This isotopic {sup 50}Ti{sup 11{sup +}} beam was used for the first time in three week-experiment with typical MIVOC stable operating conditions. After optimization, up to 19.4 {mu}A of titanium-50 in charge state 11{sup +} could be extracted from the JYFL 14 GHz ECRIS2 ion source. This measurement has demonstrated the possible use of the MIVOC method for production of an intense highly charged isotopic titanium-50 ion beam with rather low material consumption.

  8. Lead Contamination in Cocoa and Cocoa Products: Isotopic Evidence of Global Contamination

    OpenAIRE

    Rankin, Charley W.; Nriagu, Jerome O.; Aggarwal, Jugdeep K.; Arowolo, Toyin A.; Adebayo, Kola; Flegal, A. Russell

    2005-01-01

    In this article we present lead concentrations and isotopic compositions from analyses of cocoa beans, their shells, and soils from six Nigerian cocoa farms, and analyses of manufactured cocoa and chocolate products. The average lead concentration of cocoa beans was ≤ 0.5 ng/g, which is one of the lowest reported values for a natural food. In contrast, lead concentrations of manufactured cocoa and chocolate products were as high as 230 and 70 ng/g, respectively, which are consistent with mark...

  9. Production of plutonium tracers in Np-237 nuclear reactions with He-3-ions in the energy range from 26 to 60 MeV

    NARCIS (Netherlands)

    Aaltonen, J; Dendooven, P; Gromova, EA; Jakovlev, VA; Trzaska, WH

    1998-01-01

    Cross-sections for the reaction Np-237 + He-3 --> Pu-236,Pu-237,Pu-238 at He-3 bombarding energies from 26 to 60 MeV were measured. Thick-target yields, based on the measured and previously known cross-sections were constructed. The results are discussed and compared with Ether reactions leading to

  10. Reaction cross sections for protons in the energy range 220-570 MeV

    CERN Document Server

    Renberg, P U; Measday, D F; Pepin, M; Serre, Claude; Schwaller, P

    1972-01-01

    Proton reaction cross sections have been measured for targets of natural isotopic abundance of the following elements and compounds: He, Be, C, Al, Fe, Cu, Ge, Sn, Pb, H/sub 2/O, B/sub 4/C and NaI. Data for proton energies between 220 and 570 MeV have been obtained with two types of transmission-counter assembly. The total errors are of the order of +or-3%. A slight increase of the reaction cross sections with energy is observed for most of the elements studied. The results interpreted in terms of the semi-classical theory of reaction cross section as function of energy clearly demonstrate the onset of pion- production above 250 MeV. (32 refs).

  11. Investigation of recoil collection method for production of high specific activity nuclear medicine isotopes.

    Science.gov (United States)

    Cheng, K Y; Kunze, J F; Ehrhardt, G J

    1999-09-01

    High specific activity radiopharmaceuticals cannot readily be produced by (n, gamma) reactions in nuclear reactors, because the great abundance of parent atoms remaining have the same chemical characteristics as the produced isotope. We have investigated the effectiveness of using recoil atom collection methods for separating the produced radioisotope. Gold-198, produced from isotopically pure (natural) gold-197, was chosen for these experiments, which were run in the high flux (approximately 10(14) n/cm2 s thermal flux) of the reflector of the University of Missouri Research Reactor. Seven separate experiments were run, with a 2 mm separation between the emitter and the collector. Collection efficiencies were only a few percent of the radioisotope atoms produced in the top atomic layer of the emitter, instead of the 30% range anticipated. Furthermore, the collected radioisotope, instead of being nearly pure, contained a large quantity of the parent. Unless the reason for the "contamination" of product with the parent can be reduced by several orders of magnitude, this "surface hot atom recoil" method appears to offer no practical application for nuclear medicine isotope production.

  12. Production and separation of neutron-rich rare isotopes around and below the Fermi energy

    CERN Document Server

    Souliotis, G A; Chubarian, G; Yennello, S J

    2003-01-01

    The production of n-rich rare isotopes around and below the Fermi energy is investigated using beams from the K500 Superconducting Cyclotron and the MARS recoil separator at the Cyclotron Institute of Texas A and M University. The experimental results from the reactions of 25 MeV/nucleon sup 8 sup 6 Kr + sup 6 sup 4 Ni and 21 MeV/nucleon sup 1 sup 2 sup 4 Sn + sup 1 sup 2 sup 4 Sn are presented and compared with simulations. The calculations involve a deep inelastic transfer (DIT) code for the primary interaction stage followed by the code GEMINI for the de-excitation stage. The results are also compared with the EPAX parametrization. The data on the 25 MeV/nucleon sup 8 sup 6 Kr + sup 6 sup 4 Ni reaction show that both proton-removal and several-neutron pick-up isotopes are produced. An enhancement is observed in the production of n-rich isotopes close to the projectile relative to the predictions of DIT/GEMINI and the expectations of EPAX. The data of 21 MeV/nucleon sup 1 sup 2 sup 4 Sn + sup 1 sup 2 sup 4 ...

  13. Nuclear excitation functions of proton-induced reactions (Ep = 35-90 MeV) from Fe, Cu, and Al

    Science.gov (United States)

    Graves, Stephen A.; Ellison, Paul A.; Barnhart, Todd E.; Valdovinos, Hector F.; Birnbaum, Eva R.; Nortier, Francois M.; Nickles, Robert J.; Engle, Jonathan W.

    2016-11-01

    Fe, Cu, and Al stacked foils were irradiated by 90 MeV protons at the Los Alamos Neutron Science Center's Isotope Production Facility to measure nuclear cross sections for the production of medically relevant isotopes, such as 52gMn, 54Mn, 48Cr, 55Co, 58mCo and 57Ni. The decay of radioactive isotopes produced during irradiation was monitored using high-purity germanium gamma spectroscopy over the months following irradiation. Proton fluence was determined using the natAl(p,x)22Na, natCu(p,x)62Zn natCu(p,x)65Zn, and natCu(p,x)56Co monitor reactions. Calculated cross sections were compared against literature values and theoretical TALYS predictions. Notably this work includes the first reported independent cross section measurements of natCu(p,x)58mCo and natCu(p,x)58gCo.

  14. Ion beam production and study of radioactive isotopes with the laser ion source at ISOLDE

    Science.gov (United States)

    Fedosseev, Valentin; Chrysalidis, Katerina; Day Goodacre, Thomas; Marsh, Bruce; Rothe, Sebastian; Seiffert, Christoph; Wendt, Klaus

    2017-08-01

    At ISOLDE the majority of radioactive ion beams are produced using the resonance ionization laser ion source (RILIS). This ion source is based on resonant excitation of atomic transitions by wavelength tunable laser radiation. Since its installation at the ISOLDE facility in 1994, the RILIS laser setup has been developed into a versatile remotely operated laser system comprising state-of-the-art solid state and dye lasers capable of generating multiple high quality laser beams at any wavelength in the range of 210-950 nm. A continuous programme of atomic ionization scheme development at CERN and at other laboratories has gradually increased the number of RILIS-ionized elements. At present, isotopes of 40 different elements have been selectively laser-ionized by the ISOLDE RILIS. Studies related to the optimization of the laser-atom interaction environment have yielded new laser ion source types: the laser ion source and trap and the versatile arc discharge and laser ion source. Depending on the specific experimental requirements for beam purity or versatility to switch between different ionization mechanisms, these may offer a favourable alternative to the standard hot metal cavity configuration. In addition to its main purpose of ion beam production, the RILIS is used for laser spectroscopy of radioisotopes. In an ongoing experimental campaign the isotope shifts and hyperfine structure of long isotopic chains have been measured by the extremely sensitive in-source laser spectroscopy method. The studies performed in the lead region were focused on nuclear deformation and shape coexistence effects around the closed proton shell Z = 82. The paper describes the functional principles of the RILIS, the current status of the laser system and demonstrated capabilities for the production of different ion beams including the high-resolution studies of short-lived isotopes and other applications of RILIS lasers for ISOLDE experiments. This article belongs to the Focus on

  15. Production Potential of 47Sc Using Spallation Neutron Flux at the Los Alamos Isotope Production Facility

    Science.gov (United States)

    2014-03-27

    to form bonds with various potential carrier isotopes, notably acyclic polyamino-polycarboxylate ligands and folic acid , and other aminopolycarboxylic...aminopolycarboxylic acids , such as folate conjugates, which are useful as tumor biomarkers or antigens. Its thera- peutic beta emissions at 441.1 keV (Eβ...deal of time to mentor and assist this effort. It was an honor to be able to learn from Meiring’s knowledge and vast experience in the field. Dr. Eva

  16. Extension of the energy range of the experimental activation cross-sections data of longer-lived products of proton induced nuclear reactions on dysprosium up to 65 MeV

    CERN Document Server

    Tárkányi, F; Takács, S; Hermanne, A; Ignatyuk, A V

    2016-01-01

    Activation cross-sections data of longer-lived products of proton induced nuclear reactions on dysprosium were extended up to 65 MeV by using stacked foil irradiation and gamma spectrometry experimental methods. Experimental cross-sections data for the formation of the radionuclides $^{159}$Dy, $^{157}$Dy, $^{155}$Dy, $^{161}$Tb, $^{160}$Tb, $^{156}$Tb, $^{155}$Tb, $^{154m2}$Tb, $^{154m1}$Tb, $^{154g}$Tb, $^{153}$Tb, $^{152}$Tb and $^{151}$Tb are reported in the 36-65 MeV energy range, and compared with an old dataset from 1964. The experimental data were also compared with the results of cross section calculations of the ALICE and EMPIRE nuclear model codes and of the TALYS nuclear reaction model code as listed in the latest on-line libraries TENDL 2013.

  17. Extension of the energy range of the experimental activation cross-sections data of longer-lived products of proton induced nuclear reactions on dysprosium up to 65MeV.

    Science.gov (United States)

    Tárkányi, F; Ditrói, F; Takács, S; Hermanne, A; Ignatyuk, A V

    2015-04-01

    Activation cross-sections data of longer-lived products of proton induced nuclear reactions on dysprosium were extended up to 65MeV by using stacked foil irradiation and gamma spectrometry experimental methods. Experimental cross-sections data for the formation of the radionuclides (159)Dy, (157)Dy, (155)Dy, (161)Tb, (160)Tb, (156)Tb, (155)Tb, (154m2)Tb, (154m1)Tb, (154g)Tb, (153)Tb, (152)Tb and (151)Tb are reported in the 36-65MeV energy range, and compared with an old dataset from 1964. The experimental data were also compared with the results of cross section calculations of the ALICE and EMPIRE nuclear model codes and of the TALYS nuclear reaction model code as listed in the latest on-line libraries TENDL 2013. Copyright © 2015. Published by Elsevier Ltd.

  18. Production cross sections of discrete gamma-ray resulting from interaction of 14. 2 MeV neutron with Pb and Bi

    Energy Technology Data Exchange (ETDEWEB)

    Wu Youngshun; Shen Ronglin; Shi Xiamin; Xing Jinqiang; Ding Dazhao

    1982-11-01

    The differential cross sections of gamma-rays produced in interation of 14.2 MeV neutron with natural lead and bismuth have been measured at 55/sup 0/ (lab). The complete shield Ge (Li) spectrometer with time-of-flight technique gated by associated particle in T(d,n) reaction was used. The gamma-ray spectra from 14.2 MeV neutron interactions with /sup 238/U and natural Tungsten have been measured as well. For Pb and Bi, tens of discrete gamma-rays were identified. Some of thme have not been reported in previous work. The effects of attenuation and multiple scattering of neutron and the gamma-ray self-absorption in sample are corrected by Monte-Carlo method. The experimental results are compared with others.

  19. Measurements of production cross sections of 10Be and 26Al by 120 GeV and 392 MeV proton bombardment of 89Y, 159Tb, and natCu targets

    Science.gov (United States)

    Sekimoto, S.; Okumura, S.; Yashima, H.; Matsushi, Y.; Matsuzaki, H.; Matsumura, H.; Toyoda, A.; Oishi, K.; Matsuda, N.; Kasugai, Y.; Sakamoto, Y.; Nakashima, H.; Boehnlein, D.; Coleman, R.; Lauten, G.; Leveling, A.; Mokhov, N.; Ramberg, E.; Soha, A.; Vaziri, K.; Ninomiya, K.; Omoto, T.; Shima, T.; Takahashi, N.; Shinohara, A.; Caffee, M. W.; Welten, K. C.; Nishiizumi, K.; Shibata, S.; Ohtsuki, T.

    2015-10-01

    The production cross sections of 10Be and 26Al were measured by accelerator mass spectrometry using 89Y, 159Tb, and natCu targets bombarded by protons with energies Ep of 120 GeV and 392 MeV. The production cross sections obtained for 10Be and 26Al were compared with those previously reported using Ep = 50 MeV-24 GeV and various targets. It was found that the production cross sections of 10Be monotonically increased with increasing target mass number when the proton energy was greater than a few GeV. On the other hand, it was also found that the production cross sections of 10Be decreased as the target mass number increased from that of carbon to those near the mass numbers of nickel and zinc when the proton energy was below approximately 1 GeV. They also increased as the target mass number increased from near those of nickel and zinc to that of bismuth, in the same proton energy range. Similar results were observed in the production cross sections of 26Al, though the absolute values were quite different between 10Be and 26Al. The difference between these production cross sections may depend on the impact parameter (nuclear radius) and/or the target nucleus stiffness.

  20. Assessment of the production of medical isotopes using the Monte Carlo code FLUKA: Simulations against experimental measurements

    Energy Technology Data Exchange (ETDEWEB)

    Infantino, Angelo, E-mail: angelo.infantino@unibo.it [Department of Industrial Engineering, Montecuccolino Laboratory, University of Bologna, Via dei Colli 16, 40136 Bologna (Italy); Oehlke, Elisabeth [TRIUMF, 4004 Wesbrook Mall, V6T 2A3 Vancouver, BC (Canada); Department of Radiation Science & Technology, Delft University of Technology, Postbus 5, 2600 AA Delft (Netherlands); Mostacci, Domiziano [Department of Industrial Engineering, Montecuccolino Laboratory, University of Bologna, Via dei Colli 16, 40136 Bologna (Italy); Schaffer, Paul; Trinczek, Michael; Hoehr, Cornelia [TRIUMF, 4004 Wesbrook Mall, V6T 2A3 Vancouver, BC (Canada)

    2016-01-01

    The Monte Carlo code FLUKA is used to simulate the production of a number of positron emitting radionuclides, {sup 18}F, {sup 13}N, {sup 94}Tc, {sup 44}Sc, {sup 68}Ga, {sup 86}Y, {sup 89}Zr, {sup 52}Mn, {sup 61}Cu and {sup 55}Co, on a small medical cyclotron with a proton beam energy of 13 MeV. Experimental data collected at the TR13 cyclotron at TRIUMF agree within a factor of 0.6 ± 0.4 with the directly simulated data, except for the production of {sup 55}Co, where the simulation underestimates the experiment by a factor of 3.4 ± 0.4. The experimental data also agree within a factor of 0.8 ± 0.6 with the convolution of simulated proton fluence and cross sections from literature. Overall, this confirms the applicability of FLUKA to simulate radionuclide production at 13 MeV proton beam energy.

  1. Interplay of community dynamics, temperature, and productivity on the hydrogen isotope signatures of lipid biomarkers

    Science.gov (United States)

    Nemiah Ladd, S.; Dubois, Nathalie; Schubert, Carsten J.

    2017-09-01

    The hydrogen isotopic composition (δ2H) of lipid biomarkers has diverse applications in the fields of paleoclimatology, biogeochemistry, and microbial community dynamics. Large changes in hydrogen isotope fractionation have been observed among microbes with differing core metabolisms, while environmental factors including temperature and nutrient availability can affect isotope fractionation by photoautotrophs. Much effort has gone into studying these effects under laboratory conditions with single species cultures. Moving beyond controlled environments and quantifying the natural extent of these changes in freshwater lacustrine settings and identifying their causes is essential for robust application of δ2H values of common short-chain fatty acids as a proxy of net community metabolism and of phytoplankton-specific biomarkers as a paleohydrologic proxy. This work targets the effect of community dynamics, temperature, and productivity on 2H/1H fractionation in lipid biomarkers through a comparative time series in two central Swiss lakes: eutrophic Lake Greifen and oligotrophic Lake Lucerne. Particulate organic matter was collected from surface waters at six time points throughout the spring and summer of 2015, and δ2H values of short-chain fatty acids, as well as chlorophyll-derived phytol and the diatom biomarker brassicasterol, were measured. We paired these measurements with in situ incubations conducted with NaH13CO3, which were used to calculate the production rates of individual lipids in lake surface water. As algal productivity increased from April to June, net discrimination against 2H in Lake Greifen increased by as much as 148 ‰ for individual fatty acids. During the same time period in Lake Lucerne, net discrimination against 2H increased by as much as 58 ‰ for individual fatty acids. A large portion of this signal is likely due to a greater proportion of heterotrophically derived fatty acids in the winter and early spring, which are displaced by

  2. Use of LEU in the aqueous homogeneous medical isotope production reactor

    Energy Technology Data Exchange (ETDEWEB)

    Ball, R.M. [Babock & Wilcox, Lynchburg, VA (United States)

    1997-08-01

    The Medical Isotope Production Reactor (MIPR) is an aqueous solution of uranyl nitrate in water, contained in an aluminum cylinder immersed in a large pool of water which can provide both shielding and a medium for heat exchange. The control rods are inserted at the top through re-entrant thimbles. Provision is made to remove radiolytic gases and recombine emitted hydrogen and oxygen. Small quantities of the solution can be continuously extracted and replaced after passing through selective ion exchange columns, which are used to extract the desired products (fission products), e.g. molybdenum-99. This reactor type is known for its large negative temperature coefficient, the small amount of fuel required for criticality, and the ease of control. Calculation using TWODANT show that a 20% U-235 enriched system, water reflected can be critical with 73 liters of solution.

  3. Global Xenon-133 Emission Inventory Caused by Medical Isotope Production and Derived from the Worldwide Technetium-99m Demand

    Science.gov (United States)

    Kalinowski, Martin B.; Grosch, Martina; Hebel, Simon

    2014-03-01

    Emissions from medical isotope production are the most important source of background for atmospheric radioxenon measurements, which are an essential part of nuclear explosion monitoring. This article presents a new approach for estimating the global annual radioxenon emission inventory caused by medical isotope production using the amount of Tc-99m applications in hospitals as the basis. Tc-99m is the most commonly used isotope in radiology and dominates the medical isotope production. This paper presents the first estimate of the global production of Tc-99m. Depending on the production and transport scenario, global xenon emissions of 11-45 PBq/year can be derived from the global isotope demand. The lower end of this estimate is in good agreement with other estimations which are making use of reported releases and realistic process simulations. This proves the validity of the complementary assessment method proposed in this paper. It may be of relevance for future emission scenarios and for estimating the contribution to the global source term from countries and operators that do not make sufficient radioxenon release information available. It depends on sound data on medical treatments with radio-pharmaceuticals and on technical information on the production process of the supplier. This might help in understanding the apparent underestimation of the global emission inventory that has been found by atmospheric transport modelling.

  4. MeV fullerene impacts on mica

    Energy Technology Data Exchange (ETDEWEB)

    Doebeli, M.; Scandella, L. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Ames, F. [Eidgenoessische Technische Hochschule, Zurich (Switzerland)

    1997-09-01

    Hillock heights on mica irradiated with MeV C{sub 60} ions have been investigated systematically. Results show that the small range of secondary particles along the track plays a crucial role in defect production. (author) figs., tab., refs.

  5. The production of ultra-high purity single isotopes or tailored isotope mixtures by ICP-MS

    Energy Technology Data Exchange (ETDEWEB)

    Liezers, Martin; Farmer, Orville T.; Dion, Michael P.; Thomas, Linda MP; Eiden, Gregory C.

    2015-01-01

    We report the development and testing of a simple collector arrangement for a commercial quadrupole ICP-MS that for the first time has been used to produce small quantities of highly enriched (>99.99%) single isotopes, with deposition rates >10 ng/hour. The collector assembly replaces the standard instrument detector allowing for implantation with simultaneous monitoring of the incident ion current. Even under zero bias implant conditions, low energy (<10 eV), ion collection efficiency was observed to be very high ~99%. 151Eu ion currents of 0.1-0.5 nA were collected on a simple, planar foil without resorting to any type of cup configuration. Recovery of the enriched isotope from such foils is much simpler than from a more complex cup configuration. High rejection of adjacent mass isotopes was demonstrated by selectively implanting 167Er without any discernible co-implantation of 166Er and 168Er. The important analytical possibilities of the new approach to isotope ratio measurement, tracer purification and radiation measurements are discussed.

  6. Measurement of cross sections for the scattering of neutrons in the energy range from 2 MeV to 4 MeV with the {sup 15}N(p,n) reaction as neutron source; Messung von Wirkungsquerschnitten fuer die Streuung von Neutronen im Energiebereich von 2 MeV bis 4 MeV mit der {sup 15}N(p,n)-Reaktion als Neutronenquelle

    Energy Technology Data Exchange (ETDEWEB)

    Poenitz, Erik

    2010-04-26

    In future nuclear facilities, the materials lead and bismuth can play a more important role than in today's nuclear reactors. Reliable cross section data are required for the design of those facilities. In particular the neutron transport in the lead spallation target of an Accelerator-Driven Subcritical Reactor strongly depends on the inelastic neutron scattering cross sections in the energy region from 0.5 MeV to 6 MeV. In the recent 20 years, elastic and inelastic neutron scattering cross sections were measured with high precision for a variety of elements at the PTB time-of-flight spectrometer. The D(d,n) reaction was primarily used for the production of neutrons. Because of the Q value of the reaction and the available deuteron energies, neutrons in the energy range from 6 MeV to 16 MeV can be produced. For the cross section measurement at lower energies, however, another neutron producing reaction is required. The {sup 15}N(p,n){sup 15}O reaction was chosen, as it allows the production of monoenergetic neutrons with up to 5.7MeV energy. In this work, the {sup 15}N(p,n) reaction was studied with focus on the suitability as a source for monoenergetic neutrons in scattering experiments. This includes the measurement of differential cross sections for the neutron producing reaction and the choice of optimum target conditions. Differential elastic and inelastic neutron scattering cross sections were measured for lead at four energies in the region from 2 MeV to 4 MeV incident neutron energy using the time-of-flight technique. A lead sample with natural isotopic composition was used. NE213 liquid scintillation detectors with well-known detection efficiencies were used for the detection of the scattered neutrons. Angle-integrated cross sections were determined by a Legendre polynomial expansion using least-squares methods. Additionally, measurements were carried out for isotopically pure {sup 209}Bi and {sup 181}Ta samples at 4 MeV incident neutron energy

  7. Estimates of Radioxenon Released from Southern Hemisphere Medical isotope Production Facilities Using Measured Air Concentrations and Atmospheric Transport Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Eslinger, Paul W.; Friese, Judah I.; Lowrey, Justin D.; McIntyre, Justin I.; Miley, Harry S.; Schrom, Brian T.

    2014-09-01

    Abstract The International Monitoring System (IMS) of the Comprehensive-Nuclear-Test-Ban-Treaty monitors the atmosphere for radioactive xenon leaking from underground nuclear explosions. Emissions from medical isotope production represent a challenging background signal when determining whether measured radioxenon in the atmosphere is associated with a nuclear explosion prohibited by the treaty. The Australian Nuclear Science and Technology Organisation (ANSTO) operates a reactor and medical isotope production facility in Lucas Heights, Australia. This study uses two years of release data from the ANSTO medical isotope production facility and Xe-133 data from three IMS sampling locations to estimate the annual releases of Xe-133 from medical isotope production facilities in Argentina, South Africa, and Indonesia. Atmospheric dilution factors derived from a global atmospheric transport model were used in an optimization scheme to estimate annual release values by facility. The annual releases of about 6.8×1014 Bq from the ANSTO medical isotope production facility are in good agreement with the sampled concentrations at these three IMS sampling locations. Annual release estimates for the facility in South Africa vary from 1.2×1016 to 2.5×1016 Bq and estimates for the facility in Indonesia vary from 6.1×1013 to 3.6×1014 Bq. Although some releases from the facility in Argentina may reach these IMS sampling locations, the solution to the objective function is insensitive to the magnitude of those releases.

  8. Estimates of radioxenon released from Southern Hemisphere medical isotope production facilities using measured air concentrations and atmospheric transport modeling.

    Science.gov (United States)

    Eslinger, Paul W; Friese, Judah I; Lowrey, Justin D; McIntyre, Justin I; Miley, Harry S; Schrom, Brian T

    2014-09-01

    The International Monitoring System (IMS) of the Comprehensive-Nuclear-Test-Ban-Treaty monitors the atmosphere for radioactive xenon leaking from underground nuclear explosions. Emissions from medical isotope production represent a challenging background signal when determining whether measured radioxenon in the atmosphere is associated with a nuclear explosion prohibited by the treaty. The Australian Nuclear Science and Technology Organisation (ANSTO) operates a reactor and medical isotope production facility in Lucas Heights, Australia. This study uses two years of release data from the ANSTO medical isotope production facility and (133)Xe data from three IMS sampling locations to estimate the annual releases of (133)Xe from medical isotope production facilities in Argentina, South Africa, and Indonesia. Atmospheric dilution factors derived from a global atmospheric transport model were used in an optimization scheme to estimate annual release values by facility. The annual releases of about 6.8 × 10(14) Bq from the ANSTO medical isotope production facility are in good agreement with the sampled concentrations at these three IMS sampling locations. Annual release estimates for the facility in South Africa vary from 2.2 × 10(16) to 2.4 × 10(16) Bq, estimates for the facility in Indonesia vary from 9.2 × 10(13) to 3.7 × 10(14) Bq and estimates for the facility in Argentina range from 4.5 × 10(12) to 9.5 × 10(12) Bq.

  9. Production cross section measurements of radioactive isotopes by BigRIPS separator at RIKEN RI Beam Factory

    CERN Document Server

    Suzuki, H; Fukuda, N; Inabe, N; Kameda, D; Takeda, H; Yoshida, K; Kusaka, K; Yanagisawa, Y; Ohtake, M; Sato, H; Shimizu, Y; Baba, H; Kurokawa, M; Ohnishi, T; Tanaka, K; Tarasov, O B; Bazin, D; Morrissey, D J; Sherrill, B M; Ieki, K; Murai, D; Iwasa, N; Chiba, A; Ohkoda, Y; Ideguchi, E; Go, S; Yokoyama, R; Fujii, T; Nishimura, D; Nishibata, H; Momota, S; Lewitowicz, M; DeFrance, G; Celikovic, I; Steiger, K

    2013-01-01

    We have measured the production rates and production cross sections for a variety of radioactive isotopes which were produced from 124Xe, 48Ca, and 238U beams at an energy of 345 MeV/nucleon using the BigRIPS separator at the RIKEN Nishina Center RI Beam Factory (RIBF). Proton-rich isotopes with atomic numbers Z = 40 to 52 and neutron-rich isotopes with Z = 5 to 16 were produced by projectile fragmentation of the 124Xe and 48Ca beam on Be targets, respectively. Neutron-rich isotopes with Z = 20 to 59 were produced by in-flight fission of the 238U beam, in which both Be and Pb were used as production targets. The measured production rates and production cross sections were compared with those of the LISE++ calculations, and overall fairly good agreement has been obtained. Furthermore, in the measurements with the 124Xe beam, we have discovered four new isotopes on the proton-drip line, 85,86Ru and 81,82Mo, and obtained the clear evidence that 103Sb is particle unbound with an upper limit of 49 ns for the half-...

  10. Atmospheric transport modelling of time resolved 133Xe emissions from the isotope production facility ANSTO, Australia.

    Science.gov (United States)

    Schöppner, M; Plastino, W; Hermanspahn, N; Hoffmann, E; Kalinowski, M; Orr, B; Tinker, R

    2013-12-01

    The verification of the Comprehensive Nuclear-Test Ban Treaty (CTBT) relies amongst other things on the continuous and worldwide monitoring of radioxenon. The characterization of the existing and legitimate background, which is produced mainly by nuclear power plants and isotope production facilities, is of high interest to improve the capabilities of the monitoring network. However, the emissions from legitimate sources can usually only be estimated. For this paper historic source terms of (133)Xe emissions from the isotope production facility at ANSTO, Sydney, Australia, have been made available in a daily resolution. Based on these high resolution data, different source term sets with weekly, monthly and yearly time resolution have been compiled. These different sets are then applied together with atmospheric transport modelling (ATM) to predict the concentration time series at two radioxenon monitoring stations. The results are compared with each other in order to examine the improvement of the prediction capability depending on the used time resolution of the most dominant source term in the region.

  11. Production of 34mCl and 38Cl via the (d,α) reaction on 36Ar and natAr gas at 8.4 MeV

    OpenAIRE

    Engle, Jonathan W; Barnhart, Todd E.; DeJesus, Onofre T.; Nickles, Robert J.

    2010-01-01

    Production of 38Cl and 34mCl via the (d, α) reaction on natural argon and 36Ar reveal medical cyclotrons’ ability to supply these isotopes in small quantities. 38Cl provides an inexpensive developmental tool, while 34mCl is a positron emitter of interest in PET imaging. Production yields, cyclotron target development, cryo-recovery of enriched gases, and nucleophilic chemistry of a model compound are described.

  12. Target preparation and recovery of enriched isotopes for medical radionuclide production

    Science.gov (United States)

    Lambrecht, Richard M.; Sajjad, Munawwar; Syed, Rashid H.; Meyer, William

    1989-10-01

    A remotely-driven internal target system with an improved stationary target head and manually controlled target transfer assembly was constructed. Methodology and techniques for the preparation of targets utilized for the routine production of 67Ga, 111In, 123I, 124I, and 201Tl with a CS-30 cyclotron are described. Experiences in recovery of isotopically enriched target materials are detailed for plating, radiochemical separation, and target recovery for 21 cycles with 68Zn; 18 cycles with 112Cd; 40 cycles with 124Te; and 24 cycles with 203Tl. This represented 84, 72, 145, and 196 targets for 67Ga, 111In, 123I + 124I, and 201Tl, respectively. Data on target stability under routine production conditions at high currents are summarized.

  13. Target irradiation facility and targetry development at 160 MeV proton beam of Moscow linac

    CERN Document Server

    Zhuikov, B L; Konyakhin, N A; Vincent, J

    1999-01-01

    A facility has been built and successfully operated with the 160 MeV proton beam of Moscow Meson factory LINAC, Institute for Nuclear Research (INR) of Russian Academy of Science, Troitsk. The facility was created for various isotope production goals as well as for fundamental nuclear investigations at high intensity beam (100 mu A and more). An important part of the facility targetry system is a high-intensity beam monitoring collimator device. Measurements of the temperature distribution between collimator sectors, cooling water flow and temperature, and the beam current, provide an opportunity to compute beam losses and beam position. The target holder design allows easy insertion by manipulator and simultaneous bombardment of several different targets of various types and forms, and variation of proton energy on each target over a wide range below 160 MeV. The main target utilized for commercial sup 8 sup 2 Sr isotope production is metallic rubidium in a stainless-steel container. A regular wet chemistry ...

  14. Extension of activation cross section data of long lived products in deuteron induced nuclear reactions on platinum up to 50 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Ditrói, F., E-mail: ditroi@atomki.hu [Institute for Nuclear Research, Hungarian Academy of Sciences, Debrecen (Hungary); Tárkányi, F.; Takács, S. [Institute for Nuclear Research, Hungarian Academy of Sciences, Debrecen (Hungary); Hermanne, A. [Cyclotron Laboratory, Vrije Universiteit Brussel, Brussels (Belgium)

    2017-06-15

    Highlights: • Deuteron induced nuclear reactions on natural platinum up to 50 MeV. • Stacked foil irradiation technique. • Comparison with the TENDL-2014 and TENDL-2015 calculations. • Cross section of Au, Pt and Ir radioisotopes. • Application for Thin Layer Activation (TLA). - Abstract: In the frame of a systematical study of light ion induced nuclear reactions on platinum, activation cross sections for deuteron induced reactions were investigated. Excitation functions were measured in the 20.8–49.2 MeV energy range for the {sup nat}Pt(d,xn){sup 191,192,193,194,195,196m2,196g,198g,199}Au, {sup nat}Pt(d,x){sup 188,189,191,195m,197m,197g}Pt and {sup nat}Pt(d,x){sup 189,190,192,194m2}Ir reactions by using the stacked foil irradiation technique. The experimental results are compared with previous results from the literature and with the theoretical predictions in the TENDL-2014 and TENDL-2015 libraries. The applicability of the produced radio-tracers for wear measurements has been presented.

  15. BEST medical radioisotope production cyclotrons

    Science.gov (United States)

    Sabaiduc, Vasile; Milton, Bruce; Suthanthiran, Krishnan; Gelbart, W. Z.; Johnson, Richard R.

    2013-04-01

    Best Cyclotron Systems Inc (BCSI) is currently developing 14 MeV, 25 MeV, 35MeV and 70MeV cyclotrons for radioisotope production and research applications as well as the entire spectrum of targets and nuclear synthesis modules for the production of Positron Emission Tomography (PET), Single Photon Emission Computed Tomography (SPECT) and radiation therapy isotopes. The company is a subsidiary of Best Medical International, renowned in the field of medical instrumentation and radiation therapy. All cyclotrons have external negative hydrogen ion sources, four radial sectors with two dees in opposite valleys, cryogenic vacuum system and simultaneous beam extraction on opposite lines. The beam intensity ranges from 400 μA to 1000 μA, depending on the cyclotron energy and application [1].

  16. Combining UHPLC-High Resolution MS and Feeding of Stable Isotope Labeled Polyketide Intermediates for Linking Precursors to End Products

    DEFF Research Database (Denmark)

    Klitgaard, Andreas; Frandsen, Rasmus John Normand; Holm, Dorte Koefoed

    2015-01-01

    We present the results from stable isotope labeled precursor feeding studies combined with ultrahigh performance liquid chromatography-high resolution mass spectrometry for the identification of labeled polyketide (PK) end-products. Feeding experiments were performed with 13C8-6-methylsalicylic...... spp., YWA1 was shown to be incorporated into aurofusarin, rubrofusarin, and antibiotic Y. In A. niger, benzoic acid was shown to be incorporated into asperrubrol. Incorporation levels of 0.7–20% into the end-products were detected in wild-type strains. Thus, stable isotope labeling is a promising...

  17. Instrumentation developments for production and characterisation of Inverse Compton Scattering X-rays and first results with a 17 MeV electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Chauchat, A.S., E-mail: anne-sophie.chauchat@cea.f [CEA, DAM, DIF, F-91297 Arpajon (France); Le Flanchec, V.; Negre, J.P.; Binet, A.; Balleyguier, P. [CEA, DAM, DIF, F-91297 Arpajon (France); Brasile, J.P. [THALES Communication, 160 Bd de Valmy, F-92700 Colombes (France); Ortega, J.M. [CLIO/LCP, Batiment 201, Universite Paris-Sud, F-91405 Orsay (France)

    2010-10-01

    An X-ray Compton source is under development at the ELSA facility. The electron beam coming from the ELSA linear accelerator interacts with a laser beam to generate an X-ray flux in the direction of the electron beam. With a 17 MeV electron beam and a 532 nm laser, the resulting X-ray maximal energy is around 11 keV. The beams visualization at the interaction point is achieved via an aluminum retractable bevel-edge with an OTR surface on one side and a slightly roughened surface on the other. Thanks to an optical beamsplitter, beam images are both transmitted to a CCD camera and to a streak camera to manage the spatial and temporal overlap of the bunches. Careful beam management and electron background noise minimization were both required to observe the first Inverse Compton Scattering X-ray profile of this source on radio-luminescent imaging plates.

  18. Measurement of activation cross-section of long-lived products in deuteron induced nuclear reactions on palladium in the 30-50MeV energy range.

    Science.gov (United States)

    Ditrói, F; Tárkányi, F; Takács, S; Hermanne, A; Ignatyuk, A V

    2017-10-01

    Excitation functions were measured in the 31-49.2MeV energy range for the (nat)Pd(d,xn)(111,110m,106m,105,104g,103)Ag, (nat)Pd(d,x) (111m,109,101,100)Pd, (nat)Pd(d,x), (105,102m,102g,101m,101g,100,99m,99g)Rh and (nat)Pd(d,x)(103,97)Ru nuclear reactions by using the stacked foil irradiation technique. The experimental results are compared with our previous results and with the theoretical predictions calculated with the ALICE-D, EMPIRE-D and TALYS (TENDL libraries) codes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Production of yeastolates for uniform stable isotope labelling in eukaryotic cell culture.

    NARCIS (Netherlands)

    Egorova-Zachernyuk, T.A.; Bosman, G.J.C.G.M.; Pistorius, A.M.A.; Grip, W.J. de

    2009-01-01

    Preparation of stable isotope-labelled yeastolates opens up ways to establish more cost-effective stable isotope labelling of biomolecules in insect and mammalian cell lines and hence to employ higher eukaryotic cell lines for stable isotope labelling of complex recombinant proteins. Therefore, we e

  20. Evidence for in-situ methane production in ice based on anomalous isotope analyses

    Science.gov (United States)

    Sowers, T. A.; Priscu, J.

    2004-12-01

    Studying microbial ecology at low temperatures is important for understanding the limits of life processes as well the search for extraterrestrial life. Glacial ice sheets are special habitats where microbes have been preserved for geologically significant periods of time. Glaciers provide three distinct environments for microbial ecosystems. Subglacial lakes beneath the East Antarctic ice sheet provide one of the most intriguing environments that have yet to be explored. The upper portion of a glacier is formed from eolian derived (wind blown) materials (snow, impurities and microbes). Bulk impurity levels tend to be less than a few ppm, cell densities generally below 100 cells/ml and surface temperatures are generally below -15oC. Subglacial environments (lowest 20m), on the other hand, tend to have (by comparison with the overlying glacier ) extremely high impurity concentrations, cell densities on the order of 106 cells/ml, and temperatures close to the pressure melting point (~ 0oC). Microbial communities in the subglacial environments are comprised of eolian derived organisms that have traveled vertically through the ice sheet as well as organisms that inhabited the soil/rock environment before the glacier formed. Cell density measurements in glacier ice are fairly straightforward given proper cleaning techniques. Whether or not the cells in a glacier are able to grow (or at least maintain their metabolic functionality) while immured in the glacier has yet to be determined. This question remains unanswered largely because the metabolic rates of microbial communities in ice have not been measured in the lab. One way to infer in-situ microbial activity in ice is to analyze the elemental and isotopic composition of gaseous metabolic byproducts that are retained in the ice matrix. We present two case studies in which the measured methane (CH4) concentration and isotope values in ice result from in-situ production. Methane measurements spanning the last 25kyr from

  1. Evolution of the biological productivity during the last deglaciations using the triple isotopic composition of oxygen

    Science.gov (United States)

    Favre, Violaine; Extier, Thomas; Landais, Amaelle; Kageyama, Masa; Bopp, Laurent; Blunier, Thomas; Duchamp-Alphonse, Stéphanie; Masson-Delmotte, Valérie

    2017-04-01

    The last deglaciation is probably the best documented large climatic changes of the Quaternary. It is associated with global temperature increases of 4-5°C, significant increase of the sea level by 120 m and an increase in atmospheric CO2 concentration by 80 ppm. Understanding the combination of biochemical and physical factors responsible for this 80 ppm increase and the link with climate change is essential in the current evolution of greenhouse gases concentration. Biological productivity plays a role in the change of CO2 concentration during the last deglaciation. However, the lack of direct and global tracers of biological productivity makes it difficult to quantify and date the global change of productivity over the last deglaciation. Here, we use the triple isotopic composition of oxygen (δ17O of O2) over the last deglaciation obtained with a 300 years resolution on the NEEM ice core to depict the change of global productivity on this period. δ17O of O2 is indeed responding to the variations of O2 flux from the biosphere albeit in a complex manner. To help its interpretation, we thus combine these measurements with O2 fluxes obtained from the coupled climate model of IPSL over the last deglaciation. Finally, we compare the dynamic and amplitude of the δ17O of O2 change over the last deglaciation with variations obtained on previous deglaciations using new δ17O of O2 data obtained from the Dome C ice core.

  2. Near-threshold pion production with radioactive beams at the Rare Isotope Accelerator

    CERN Document Server

    Li, B A; Zuo, W; Li, Bao-An; Yong, Gao-Chan; Zuo, Wei

    2005-01-01

    Using an isospin- and momentum-dependent transport model we study near-threshold pion production in heavy-ion collisions induced by radioactive beams at the planned Rare Isotope Accelerator (RIA). We revisit the question of probing the high density behavior of nuclear symmetry energy $E_{sym}(\\rho)$ using the $\\pi^-/\\pi^+$ ratio. It is found that both the total and differential $\\pi^-/\\pi^+$ ratios remain sensitive to the $E_{sym}(\\rho)$ when the momentum-dependence of both the isoscalar and isovector potentials are consistently taken into account. Moreover, the multiplicity and spectrum of $\\pi^-$ mesons are found more sensitive to the $E_{sym}(\\rho)$ than those of $\\pi^+$ mesons. Finally, effects of the Coulomb potential on the pion spectra and $\\pi^-/\\pi^+$ ratio are also discussed.

  3. Excitation functions of 125Te(p, xn)-reactions from their respective thresholds up to 100 MeV with special reference to the production of 124I.

    Science.gov (United States)

    Hohn, A; Nortier, F M; Scholten, B; van der Walt, T N; Coenen, H H; Qaim, S M

    2001-08-01

    Excitation functions of the nuclear reactions 125Te(p, xn) (119,120m, 120g, 121,122,123,124,125)I were measured for the first time from their respective thresholds up to 100 MeV using the stacked-foil technique. Thin samples were prepared by electrolytic deposition of 98.3% enriched 125Te on Ti-backing. In addition to experimental studies, excitation functions were calculated by the modified hybrid model code ALICE-IPPE. The experimental and theoretical data generally showed good agreement. From the measured cross section data, integral yields of (123,124,125)I were calculated. The energy range Ep 21 --> 15 MeV appears to be very suitable for the production of the medically interesting radionuclide 124I (T(1/2) = 4.18 d; I(beta)+ = 25%). The thick target yield of 124I amounts to 81 MBq/microA h and the level of 125I-impurity to 0.9%. The 125Te(p,2n)124I reaction gives 124I yield about four times higher than the commonly used 124Te(p,n)124I and 124Te(d,2n)124I reactions. The proposed production energy range is too high for small cyclotrons but large quantities of 124I can be produced with medium-sized commercial machines.

  4. Estimation of double differential angle-dependent neutron production cross sections from tritons on 197Au at energies from 5.97 to 19.14 MeV

    CERN Document Server

    Drosg, Manfred

    2016-01-01

    Estimated cross sections for neutron production from triton bombardment of gold are deduced from measurements of triton interactions with gas targets that used gold as a triton beam stop material. Differential cross sections for production of neutrons from 5.97-, 7.47-, 10.45-, 16.41- and 19.14-MeV tritons on 197Au were evaluated. Corrections for the neutron interaction in gold, in the target structure and in the air of the flight path were obtained by means of a Monte Carlo technique. Uncorrelated scale uncertainties range from 24 to 41% whereas those of double differential cross sections range from 0.2 to 5%. Based on these cross section data, calculation of neutron yield at 0o from fully stopped tritons at 20.22 MeV agree with an independent measurement. Least-squares fits with a gamma distribution model indicate an anisotropy in the high energy portion of the neutron spectra. Legendre polynomial fits of differential cross sections are reported. All neutron cross section data are made available through the...

  5. Isotopic insights into methane production, oxidation, and emissions in Arctic polygon tundra.

    Science.gov (United States)

    Vaughn, Lydia J S; Conrad, Mark E; Bill, Markus; Torn, Margaret S

    2016-10-01

    Arctic wetlands are currently net sources of atmospheric CH4 . Due to their complex biogeochemical controls and high spatial and temporal variability, current net CH4 emissions and gross CH4 processes have been difficult to quantify, and their predicted responses to climate change remain uncertain. We investigated CH4 production, oxidation, and surface emissions in Arctic polygon tundra, across a wet-to-dry permafrost degradation gradient from low-centered (intact) to flat- and high-centered (degraded) polygons. From 3 microtopographic positions (polygon centers, rims, and troughs) along the permafrost degradation gradient, we measured surface CH4 and CO2 fluxes, concentrations and stable isotope compositions of CH4 and DIC at three depths in the soil, and soil moisture and temperature. More degraded sites had lower CH4 emissions, a different primary methanogenic pathway, and greater CH4 oxidation than did intact permafrost sites, to a greater degree than soil moisture or temperature could explain. Surface CH4 flux decreased from 64 nmol m(-2)  s(-1) in intact polygons to 7 nmol m(-2)  s(-1) in degraded polygons, and stable isotope signatures of CH4 and DIC showed that acetate cleavage dominated CH4 production in low-centered polygons, while CO2 reduction was the primary pathway in degraded polygons. We see evidence that differences in water flow and vegetation between intact and degraded polygons contributed to these observations. In contrast to many previous studies, these findings document a mechanism whereby permafrost degradation can lead to local decreases in tundra CH4 emissions.

  6. Isotope dilution ICP-MS with laser-assisted sample introduction for direct determination of sulfur in petroleum products.

    Science.gov (United States)

    Boulyga, Sergei F; Heilmann, Jens; Heumann, Klaus G

    2005-08-01

    Inductively coupled plasma isotope dilution mass spectrometry (ICP-IDMS) with direct laser-assisted introduction of isotope-diluted samples into the plasma, using a laser ablation system with high ablation rates, was developed for accurate sulfur determinations in different petroleum products such as 'sulfur-free' premium gasoline, diesel fuel, and heating oil. Two certified gas oil reference materials were analyzed for method validation. Two different 34S-enriched spike compounds, namely, elementary sulfur dissolved in xylene and dibenzothiophene in hexane, were synthesized and tested for their usefulness in this isotope dilution technique. The isotope-diluted sample was adsorbed on a filter-paper-like material, which was fixed in a special holder for irradiation by the laser beam. Under these conditions no time-dependent spike/analyte fractionation was only observed for the dibenzothiophene spike during the laser ablation process, which means that the measured 34S/32S isotope ratio of the isotope-diluted sample remained constant-a necessary precondition for accurate results with the isotope dilution technique. A comparison of LA-ICP-IDMS results with the certified values of the gas oil reference materials and with results obtained from ICP-IDMS analyses with wet sample digestion demonstrated the accuracy of the new LA-ICP-IDMS method in the concentration range of 9.2 microg g(-1) ('sulfur-free' premium gasoline) to 10.4 mg g(-1) (gas oil reference material BCR 107). The detection limit for sulfur by LA-ICP-IDMS is 0.04 microg g(-1) and the analysis time is only about 10 min, which therefore also qualifies this method for accurate determinations of low sulfur contents in petroleum products on a routine level.

  7. Isotope dilution ICP-MS with laser-assisted sample introduction for direct determination of sulfur in petroleum products

    Energy Technology Data Exchange (ETDEWEB)

    Boulyga, Sergei F.; Heilmann, Jens; Heumann, Klaus G. [Johannes Gutenberg-University Mainz (Germany). Institute of Inorganic Chemistry and Analytical Chemistry

    2005-08-01

    Inductively coupled plasma isotope dilution mass spectrometry (ICP-IDMS) with direct laser-assisted introduction of isotope-diluted samples into the plasma, using a laser ablation system with high ablation rates, was developed for accurate sulfur determinations in different petroleum products such as 'sulfur-free' premium gasoline, diesel fuel, and heating oil. Two certified gas oil reference materials were analyzed for method validation. Two different {sup 34}S-enriched spike compounds, namely, elementary sulfur dissolved in xylene and dibenzothiophene in hexane, were synthesized and tested for their usefulness in this isotope dilution technique. The isotope-diluted sample was adsorbed on a filter-paper-like material, which was fixed in a special holder for irradiation by the laser beam. Under these conditions no time-dependent spike/analyte fractionation was only observed for the dibenzothiophene spike during the laser ablation process, which means that the measured {sup 34}S/{sup 32}S isotope ratio of the isotope-diluted sample remained constant - a necessary precondition for accurate results with the isotope dilution technique. A comparison of LA-ICP-IDMS results with the certified values of the gas oil reference materials and with results obtained from ICP-IDMS analyses with wet sample digestion demonstrated the accuracy of the new LA-ICP-IDMS method in the concentration range of 9.2 {mu}g g{sup -1} ('sulfur-free' premium gasoline) to 10.4 mg g{sup -1} (gas oil reference material BCR 107). The detection limit for sulfur by LA-ICP-IDMS is 0.04 {mu}g g{sup -1} and the analysis time is only about 10 min, which therefore also qualifies this method for accurate determinations of low sulfur contents in petroleum products on a routine level. (orig.)

  8. Activation cross-sections of longer lived products of proton induced nuclear reactions on cobalt up to 70 MeV

    CERN Document Server

    Ditrói, F; Takács, S; Hermanne, A; Yamazaki, H; Baba, M; Mohammadi, A

    2013-01-01

    As a part of our series of studies on deuteron induced reaction on various target materials excitation functions on natural cobalt have been measured by using stacked-foil technique. In these measurements 51Cr, 55;56;57;58Co, 51Cr, 52;54;56Mn and 56;57Ni radioisotopes have been identi?fied. For the above isotopes the excitation functions were determined and compared with the literature data and with the results of EMPIRE and TALYS calculations taken from the TENDL 2011 library. The agreement with previous measurements was acceptable and we could also determine new cross-section data.

  9. Excitation functions of proton-induced reactions on natural Nd in the 10-30 MeV energy range, and production of radionuclides relevant for double-{\\beta} decay

    CERN Document Server

    Lebeda, O; Schrock, P; Štursa, J; Zuber, K; 10.1103/PhysRevC.85.014602

    2012-01-01

    A preferred candidate for neutrinoless double-{\\beta} decay, 150Nd, is present in natural neodymium at an abundance level of 5.64%. However, neodymium could be activated by cosmic rays during the period it spends on the Earth's surface. Its activation by protons is therefore of interest when it comes to estimating the possible disturbance effects and increased background during neutrinoless double-{\\beta}-decay experiments like Sudbury Neutrino Observatory plus liquid scintillator (SNO+). In most cases, we lack experimental data on proton-induced reactions on neodymium. Therefore, a measurement of cross sections has been performed for the formation of 141Pm, 143Pm, 144Pm, 146Pm, 148Pm, 148Pmm, 149Pm, 150Pm, 140Nd, 141Nd, 147Nd, 149Nd, 138Prm, 139Pr, 142Pr, and 139Ce by 10-30 MeV protons. Oxidation-protected metal foil targets of natural isotopic abundance were irradiated by the usual stacked-foil technique on the external proton beam of the isochronous cyclotron U-120M at the Nuclear Physics Institute at \\v{R...

  10. High intensity proton beam transportation through fringe field of 70 MeV compact cyclotron to beam line targets

    Science.gov (United States)

    Zhang, Xu; Li, Ming; Wei, Sumin; Xing, Jiansheng; Hu, Yueming; Johnson, Richard R.; Piazza, Leandro; Ryjkov, Vladimir

    2016-06-01

    From the stripping points, the high intensity proton beam of a compact cyclotron travels through the fringe field area of the machine to the combination magnet. Starting from there the beams with various energy is transferred to the switching magnet for distribution to the beam line targets. In the design of the extraction and transport system for the compact proton cyclotron facilities, such as the 70 MeV in France and the 100 MeV in China, the space charge effect as the beam crosses the fringe field has not been previously considered; neither has the impact on transverse beam envelope coupled from the longitudinal direction. Those have been concerned much more with the higher beam-power because of the beam loss problem. In this paper, based on the mapping data of 70 MeV cyclotron including the fringe field by BEST Cyclotron Inc (BEST) and combination magnet field by China Institute of Atomic Energy (CIAE), the beam extraction and transport are investigated for the 70 MeV cyclotron used on the SPES project at Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro (INFN-LNL). The study includes the space charge effect and longitudinal and transverse coupling mentioned above, as well as the matching of beam optics using the beam line for medical isotope production as an example. In addition, the designs of the ±45° switching magnets and the 60° bending magnet for the extracted beam with the energy from 35 MeV to 70 MeV have been made. Parts of the construction and field measurements of those magnets have been done as well. The current result shows that, the design considers the complexity of the compact cyclotron extraction area and fits the requirements of the extraction and transport for high intensity proton beam, especially at mA intensity levels.

  11. High intensity proton beam transportation through fringe field of 70 MeV compact cyclotron to beam line targets

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xu, E-mail: emmazhang103@gmail.com [China Institute of Atomic Energy (China); Li, Ming; Wei, Sumin; Xing, Jiansheng; Hu, Yueming [China Institute of Atomic Energy (China); Johnson, Richard R.; Piazza, Leandro; Ryjkov, Vladimir [BEST Cyclotron Inc (Canada)

    2016-06-01

    From the stripping points, the high intensity proton beam of a compact cyclotron travels through the fringe field area of the machine to the combination magnet. Starting from there the beams with various energy is transferred to the switching magnet for distribution to the beam line targets. In the design of the extraction and transport system for the compact proton cyclotron facilities, such as the 70 MeV in France and the 100 MeV in China, the space charge effect as the beam crosses the fringe field has not been previously considered; neither has the impact on transverse beam envelope coupled from the longitudinal direction. Those have been concerned much more with the higher beam-power because of the beam loss problem. In this paper, based on the mapping data of 70 MeV cyclotron including the fringe field by BEST Cyclotron Inc (BEST) and combination magnet field by China Institute of Atomic Energy (CIAE), the beam extraction and transport are investigated for the 70 MeV cyclotron used on the SPES project at Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro (INFN–LNL). The study includes the space charge effect and longitudinal and transverse coupling mentioned above, as well as the matching of beam optics using the beam line for medical isotope production as an example. In addition, the designs of the ±45° switching magnets and the 60° bending magnet for the extracted beam with the energy from 35 MeV to 70 MeV have been made. Parts of the construction and field measurements of those magnets have been done as well. The current result shows that, the design considers the complexity of the compact cyclotron extraction area and fits the requirements of the extraction and transport for high intensity proton beam, especially at mA intensity levels.

  12. Production and chemical isolation procedure of positron-emitting isotopes of arsenic for environmental and medical applications

    Science.gov (United States)

    Ellison, P. A.; Barnhart, T. E.; Engle, J. W.; Nickles, R. J.; DeJesus, O. T.

    2012-12-01

    The positron-emitting isotopes of arsenic have unique potential for imaging research in medical and environmental applications. The production and purification of radioarsenic from proton-irradiated natural GeO2 targets is reported. The separation procedure utilizes precipitation and anion exchange separation steps. Two anion exchange procedures were investigated. An overall arsenic decay-corrected separation yield of 80% was obtained.

  13. The production of unknown neutron-rich isotopes in $^{238}$U+$^{238}$U collisions at near-barrier energy

    CERN Document Server

    Zhao, Kai; Zhang, Yingxun; Wang, Ning; Li, Qingfeng; Shen, Caiwan; Wang, Yongjia; Wu, Xizhen

    2016-01-01

    The production cross sections for primary and residual fragments with charge number from $Z$=70 to 120 produced in the collision of $^{238}$U+$^{238}$U at 7.0 MeV/nucleon are calculated by the improved quantum molecular dynamics (ImQMD) model incorporated with the statistical evaporation model (HIVAP code). The calculation results predict that about sixty unknown neutron-rich isotopes from element Ra ($Z$=88) to Db ($Z$=105) can be produced with the production cross sections above the lower bound of $10^{-8}$ mb in this reaction. And almost all of unknown neutron-rich isotopes are emitted at the laboratory angles $\\theta_{lab}\\leq$ 60$^\\circ$. Two cases, i.e. the production of the unknown uranium isotopes with $A\\geq$ 244 and that of rutherfordium with $A\\geq$ 269 are investigated for understanding the production mechanism of unknown neutron-rich isotopes. It is found that for the former case the collision time between two uranium nuclei is shorter and the primary fragments producing the residues have smaller...

  14. Laboratory studies of carbon kinetic isotope effects on the production mechanism of particulate phenolic compounds formed by toluene photooxidation: a tool to constrain reaction pathways.

    Science.gov (United States)

    Irei, Satoshi; Rudolph, Jochen; Huang, Lin; Auld, Janeen; Collin, Fabrice; Hastie, Donald

    2015-01-08

    In this study, we examined compound-specific stable carbon isotope ratios for phenolic compounds in secondary organic aerosol (SOA) formed by photooxidation of isotope-label-free toluene. SOA generated by photooxidation of toluene using a continuous-flow reactor and an 8 m(3) indoor smog chamber was collected on filters, which were extracted with acetonitrile for compound-specific analysis. Eight phenolic compounds were identified in the extracts using a gas chromatograph coupled with a mass spectrometer, and their compound-specific stable carbon isotope ratios were determined using a gas chromatograph coupled with a combustion furnace followed by an isotope ratio mass spectrometer. The majority of products, including methylnitrophenols and methylnitrocatechols, were isotopically depleted by 5-6‰ compared to the initial isotope ratio of toluene, whereas the isotope ratio for 4-nitrophenol remained identical to that of toluene. On the basis of the reaction mechanisms proposed in previous reports, stable carbon isotope ratios of these products were calculated. By comparing the observed isotope ratios with the predicted isotope ratios, we explored possible production pathways for the particulate phenolic compounds.

  15. Detecting animal by-product intake using stable isotope ratio mass spectrometry (IRMS).

    Science.gov (United States)

    da Silva, D A F; Biscola, N P; Dos Santos, L D; Sartori, M M P; Denadai, J C; da Silva, E T; Ducatti, C; Bicudo, S D; Barraviera, B; Ferreira, R S

    2016-11-01

    Sheep are used in many countries as food and for manufacturing bioproducts. However, when these animals consume animal by-products (ABP), which is widely prohibited, there is a risk of transmitting scrapie - a fatal prion disease in human beings. Therefore, it is essential to develop sensitive methods to detect previous ABP intake to select safe animals for producing biopharmaceuticals. We used stable isotope ratio mass spectrometry (IRMS) for (13)C and (15)N to trace animal proteins in the serum of three groups of sheep: 1 - received only vegetable protein (VP) for 89 days; 2 - received animal and vegetable protein (AVP); and 3 - received animal and vegetable protein with animal protein subsequently removed (AVPR). Groups 2 and 3 received diets with 30% bovine meat and bone meal (MBM) added to a vegetable diet (from days 16-89 in the AVP group and until day 49 in the AVPR group, when MBM was removed). The AVPR group showed (15)N equilibrium 5 days after MBM removal (54th day). Conversely, (15)N equilibrium in the AVP group occurred 22 days later (76th day). The half-life differed between these groups by 3.55 days. In the AVPR group, (15)N elimination required 53 days, which was similar to this isotope's incorporation time. Turnover was determined based on natural (15)N signatures. IRMS followed by turnover calculations was used to evaluate the time period for the incorporation and elimination of animal protein in sheep serum. The δ(13)C and δ(15)N values were used to track animal protein in the diet. This method is biologically and economically relevant for the veterinary field because it can track protein over time or make a point assessment of animal feed with high sensitivity and resolution, providing a low-cost analysis coupled with fast detection. Isotopic profiles could be measured throughout the experimental period, demonstrating the potential to use the method for traceability and certification assessments. Copyright © 2016 Elsevier Ltd. All rights

  16. Energy Dependence of Fission Product Yields from 235U, 238U and 239Pu for Incident Neutron Energies Between 0.5 and 14.8 MeV

    Science.gov (United States)

    Gooden, M. E.; Arnold, C. W.; Becker, J. A.; Bhatia, C.; Bhike, M.; Bond, E. M.; Bredeweg, T. A.; Fallin, B.; Fowler, M. M.; Howell, C. R.; Kelley, J. H.; Krishichayan; Macri, R.; Rusev, G.; Ryan, C.; Sheets, S. A.; Stoyer, M. A.; Tonchev, A. P.; Tornow, W.; Vieira, D. J.; Wilhelmy, J. B.

    2016-01-01

    Fission Product Yields (FPY) have historically been one of the most observable features of the fission process. They are known to have strong variations that are dependent on the fissioning species, the excitation energy, and the angular momentum of the compound system. However, consistent and systematic studies of the variation of these FPY with energy have proved challenging. This is caused primarily by the nature of the experiments that have traditionally relied on radiochemical procedures to isolate specific fission products. Although radiochemical procedures exist that can isolate all products, each element presents specific challenges and introduces varying degrees of systematic errors that can make inter-comparison of FPY uncertain. Although of high importance in fields such as nuclear forensics and Stockpile Stewardship, accurate information about the energy dependence of neutron induced FPY are sparse, due primarily to the lack of suitable monoenergetic neutron sources. There is a clear need for improved data, and to address this issue, a collaboration was formed between Los Alamos National Laboratory (LANL), Lawrence Livermore National Laboratory (LLNL) and the Triangle Universities Nuclear Laboratory (TUNL) to measure the energy dependence of FPY for 235U, 238U and 239Pu. The measurements have been performed at TUNL, using a 10 MV Tandem Van de Graaff accelerator to produce monoenergetic neutrons at energies between 0.6 MeV to 14.8 MeV through a variety of reactions. The measurements have utilized a dual-fission chamber, with thin (10-100 μg/cm2) reference foils of similar material to a thick (100-400 mg) activation target held in the center between the chambers. This method allows for the accurate determination of the number of fissions that occurred in the thick target without requiring knowledge of the fission cross section or neutron fluence on target. Following activation, the thick target was removed from the dual-fission chamber and gamma

  17. Energy Dependence of Fission Product Yields from 235U, 238U and 239Pu for Incident Neutron Energies Between 0.5 and 14.8 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Gooden, M. E.; Arnold, C. W.; Becker, J. A.; Bhatia, C.; Bhike, M.; Bond, E. M.; Bredeweg, T. A.; Fallin, B.; Fowler, M. M.; Howell, C. R.; Kelley, J. H.; Krishichayan,; Macri, R.; Rusev, G.; Ryan, C.; Sheets, S. A.; Stoyer, M. A.; Tonchev, A. P.; Tornow, W.; Vieira, D. J.; Wilhelmy, J. B.

    2016-01-01

    Fission Product Yields (FPY) have historically been one of the most observable features of the fission process. They are known to have strong variations that are dependent on the fissioning species, the excitation energy, and the angular momentum of the compound system. However, consistent and systematic studies of the variation of these FPY with energy have proved challenging. This is caused primarily by the nature of the experiments that have traditionally relied on radiochemical procedures to isolate specific fission products. Although radiochemical procedures exist that can isolate all products, each element presents specific challenges and introduces varying degrees of systematic errors that can make inter-comparison of FPY uncertain. Although of high importance in fields such as nuclear forensics and Stockpile Stewardship, accurate information about the energy dependence of neutron induced FPY are sparse, due primarily to the lack of suitable monoenergetic neutron sources. There is a clear need for improved data, and to address this issue, a collaboration was formed between Los Alamos National Laboratory (LANL), Lawrence Livermore National Laboratory (LLNL) and the Triangle Universities Nuclear Laboratory (TUNL) to measure the energy dependence of FPY for 235U, 238U and 239Pu. The measurements have been performed at TUNL, using a 10 MV Tandem Van de Graaff accelerator to produce monoenergetic neutrons at energies between 0.6 MeV to 14.8 MeV through a variety of reactions. The measurements have utilized a dual-fission chamber, with thin (10-100 μg/cm2) reference foils of similar material to a thick (100-400 mg) activation target held in the center between the chambers. This method allows for the accurate determination of the number of fissions that occurred in the thick target without requiring knowledge of the fission cross section or neutron fluence on target. Following activation, the thick target was removed

  18. Isotopic Distributions of the l8N Fragmentation Products in Coincidence with Neutrons on Targets 197Au and 9Be

    Institute of Scientific and Technical Information of China (English)

    李湘庆; 江栋兴; 叶沿林; 华辉; 陈陶; 李智焕; 葛愉成; 王全进; 吴和宇; 靳根明; 段利敏; 肖志刚; 王宏伟; 李祖玉; 王素芳

    2002-01-01

    We present the experimental isotopic distributions of the 18 N projectile fragmentation products Li, Be,B and Cin coincidence with neutrons, as well as the inclusive ones on 197 Au and 9Be targets. In the framework of theabrasion-ablation model, these distributions are calculated for various nucleon density distributions of the projec-tile. The comparison with experimental isotopic distributions of the projectile-like fragments in coincidence withneutrons shows that the information on the nucleon density distribution of the 18N projectile can be extracted.

  19. Production Yield of C-H Cluster From Carbon Material Bombarded by MeV Ions%MeV 离子轰击碳样品引起的碳氢团簇产额

    Institute of Scientific and Technical Information of China (English)

    刘坤; 郑涛; 郭猜; 杨江燕; 田继挺; 聂锐; 马宏骥; 丁富荣

    2014-01-01

    利用北京大学2×1.7 MV静电串列加速器产生的1.5 MeV Au2+和Si+束流轰击碳纳米管样品,用二次离子飞行时间质谱方法分析了二次离子成分,通过质量已知的样品的定标,确认了轰击产生的二次离子质量。分析束流轰击后的二次离子产额,发现在此能量下二次离子产额与离子在物质中射程的横向歧离表现出正相关。%Using the time-of-flight secondary ion mass spectrometry method , the production yield of C-H cluster from carbon material bombarded by MeV ions was investigated .In the experiment ,Si+ and Au2+ ions generated by the 2 × 1.7MV tandem accelerator of Peking University were chosen as the primary ion beams .The mass of the secondary ion was calibrated by the sample with known mass .By analyzing the mass spectrum of the secondary ion bombarded by different ions ,it is found that the yield is related to the lateral straggling of ions in the material at this energy region .

  20. Archaeological reconstruction of medieval lead production: Implications for ancient metal provenance studies and paleopollution tracing by Pb isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Baron, Sandrine, E-mail: baron@lmtg.obs-mip.fr [Laboratoire des Travaux et Recherches Archeologiques sur les Cultures, les Espaces et les Societes, Universite Toulouse 2 Le Mirail, CNRS UMR 5608, Maison de la Recherche, 5 allee Antonio-Machado, 31 058 Toulouse Cedex 09 (France); Centre de Recherches Petrographiques et Geochimiques, Nancy Universite, CNRS UPR 2300, BP 20, 15 rue Notre Dame des Pauvres, 54 501 Vandoeuvre-les-Nancy (France); Le-Carlier, Cecile [Centre de Recherche en Archeologie, Archeosciences, Histoire, Universite Rennes 1, CNRS UMR 6566, Bat 24-25, Campus de Beaulieu 35042 Rennes, Cedex (France); Carignan, Jean; Ploquin, Alain [Centre de Recherches Petrographiques et Geochimiques, Nancy Universite, CNRS UPR 2300, BP 20, 15 rue Notre Dame des Pauvres, 54 501 Vandoeuvre-les-Nancy (France)

    2009-11-15

    The identification of metal provenance is often based on chemical and Pb isotope analyses of materials from the operating chain, mainly ores and metallic artefacts. Such analyses, however, have their limits. Some studies are unable to trace metallic artefacts or ingots to their ore sources, even in well-constrained archaeological contexts. Possible reasons for this difficulty are to be found among a variety of limiting factors: (i) problems of ore signatures, (ii) mixing of different ores (alloys), (iii) the use of additives during the metallurgical process, (iv) metal recycling and (v) possible Pb isotopic fractionation during metal production. This paper focuses on the issue of Pb isotope fractionation during smelting to address the issue of metal provenance. Through an experimental reconstruction of argentiferous Pb production in the medieval period, an attempt was made to better understand and interpret the Pb isotopic composition of ore smelting products. It is shown that the measured differences (outside the total external uncertainties of 0.005 (2*sd) for {sup 206}Pb/{sup 204}Pb ratios) in Pb signatures measured between ores, slag and smoke are not due to Pb mass fractionation processes, but to (1) ore heterogeneity ({Delta}{sup 206}Pb/{sup 204}Pb{sub slag-ores} = 0.066) and (2) the use of additives during the metallurgical process ({Delta}{sup 206}Pb/{sup 204}Pb{sub slag-ores} = 0.083). Even if these differences are due to causes (1) and/or (2), smoke from the ore reduction appears to reflect the ore mining area without a significant disturbance of its Pb signature for all the isotopic ratios ({Delta}{sup 206}Pb/{sup 204}Pb{sub smokes-ores} = 0.026). Thus, because the isotopic heterogeneity of the mining district and additives is averaged in slags, slag appears as the most relevant product to identify ancient metal provenance. Whereas aiming at identifying a given mine seems beyond the possibilities provided by the method, searching for the mining district

  1. Accelerator based production of auger-electron-emitting isotopes for radionuclide therapy

    Energy Technology Data Exchange (ETDEWEB)

    Thisgaard, H.

    2008-08-15

    In this research project the focus has been on the identification and production of new, unconventional Auger-electron-emitting isotopes for targeted radionuclide therapy of cancer. Based on 1st principles dosimetry calculations on the subcellular level, the Auger-emitter 119Sb has been identified as a potent candidate for therapy. The corresponding imaging analogue 117Sb has been shown from planar scintigraphy and single-photon emission computed tomography (SPECT) to be suitable for SPECT-based dosimetry of a future Sb-labeled radiopharmaceutical. The production method of these radioisotopes has been developed using a low-energy cyclotron via the nuclear reactions 119Sn(p,n)119Sb and 117Sn(p,n)117Sb including measurements of the excitation function for the former reaction. Moreover, a new high-yield radiochemical separation method has been developed to allow the subsequent separation of the produced 119Sb from the enriched 119Sn target material with high radionuclidic- and chemical purity. A method that also allows efficient recovery of the 119Sn for recycling. To demonstrate the ability of producing therapeutic quantities of 119Sb and other radioisotopes for therapy with a low-energy cyclotron, two new 'High Power' cyclotron targets were developed in this study. The target development was primarily based on theoretical thermal modeling calculations using finite-element-analysis software. With these targets, I have shown that it will be possible to produce several tens of GBq of therapeutics isotopes (e.g. 119Sb or 64Cu) using the PETtrace cyclotron commonly found at the larger PET-centers in the hospitals. Finally, research in a new method to measure the radiotoxicity of Auger-emitters invitro using cellular microinjection has been carried out. The purpose of this method is to be able to experimentally evaluate and compare the potency of the new and unconventional Auger-emitters (e.g. 119Sb). However, due to experimental complications, the development

  2. Discovery of the Cobalt Isotopes

    OpenAIRE

    Szymanski, T.; Thoennessen, M.

    2009-01-01

    Twenty-six cobalt isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  3. Discovery of the Arsenic Isotopes

    CERN Document Server

    Shore, A; Heim, M; Schuh, A; Thoennessen, M

    2009-01-01

    Twenty-nine arsenic isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  4. New measurements of excitation functions of 186W(p,x) nuclear reactions up to 65 MeV. Production of a 178W/178mTa generator

    Science.gov (United States)

    Tárkányi, F.; Ditrói, F.; Takács, S.; Hermanne, A.

    2017-01-01

    New experimental excitation functions for proton induced reactions on natW are presented in the 32-65 MeV energy range. The cross-sections for natW(p,xn)186,184m,184g,183, 182m,182g,181Re, natW(p,x)178W, natW(p,x)183,182, 180m, 177,176,175Ta, 175Hf and 177Lu were measured via an activation method by using a stacked-foil irradiation technique and high resolution gamma-ray spectroscopy. The results were compared with predicted values obtained with the nuclear reaction code TALYS (results taken from the TENDL 2014 and TENDL 2015 on-line libraries). Production routes of the medically relevant radionuclides 186Re, the 178W → 178Ta generator and 181W are discussed.

  5. Measurement of Fragment Production Cross Sections in the $^{12}$C+$^{12}$C and $^{12}$C+$^{197}$Au Reactions at 62 $A$ MeV for Hadrontherapy and Space Radiation Protection

    CERN Document Server

    Tropea, S; Agodi, C; Blancato, A A; Bondì, M; Cappuzzello, F; Carbone, D; Cavallaro, M; Cirrone, G A P; Cuttone, G; Giacoppo, F; Nicolosi, D; Pandola, L; Raciti, G; Rapisarda, E; Romano, F; Sardina, D; Scuderi, V; Sfienti, C

    2014-01-01

    Over the last twenty years, there has been a renewed interest in nuclear fragmentation studies for both hadrontherapy applications and space radiation protection. In both fields, fragmentation cross sections are needed to predict the effects of the ions nuclear interactions within the patient’s and the astronaut’s body. Indeed, the Monte Carlo codes used in planning tumor treatments and space missions must be tuned and validated by experimental data. However, only a limited set of fragmentation cross sections are available in literature, especially at Fermi energies. Therefore, we have studied the production of secondary fragments in the 12 C+ 12 C and 12 C+ 197 Au reactions at 62 A MeV. In this work, the measured 4 He cross sections angular distributions at four selected angles are presented and compared.

  6. New measurements of excitation functions of {sup 186}W(p,x) nuclear reactions up to 65 MeV. Production of a {sup 178}W/{sup 178m}Ta generator

    Energy Technology Data Exchange (ETDEWEB)

    Tárkányi, F.; Ditrói, F.; Takács, S. [Institute of Nuclear Research (ATOMKI), Debrecen (Hungary); Hermanne, A., E-mail: aherman@vub.ac.be [Cyclotron Department, Vrije Universiteit Brussel, (VUB), Brussels (Belgium)

    2017-01-15

    New experimental excitation functions for proton induced reactions on {sup nat}W are presented in the 32–65 MeV energy range. The cross-sections for {sup nat}W(p,xn){sup 186,184m,184g,183,} {sup 182m,182g,181}Re, {sup nat}W(p,x){sup 178}W{sup ,} {sup nat}W(p,x){sup 183,182,} {sup 180m,} {sup 177,176,175}Ta, {sup 175}Hf and {sup 177}Lu were measured via an activation method by using a stacked-foil irradiation technique and high resolution gamma-ray spectroscopy. The results were compared with predicted values obtained with the nuclear reaction code TALYS (results taken from the TENDL 2014 and TENDL 2015 on-line libraries). Production routes of the medically relevant radionuclides {sup 186}Re, the {sup 178}W → {sup 178}Ta generator and {sup 181}W are discussed.

  7. Proton induced K X-ray production cross sections of the elements Al, Si, Ti, Fe, and Ni in the 0.7–2.0 MeV energy range

    Energy Technology Data Exchange (ETDEWEB)

    Bertol, Ana Paula Lamberti [Programa de Pós Graduação em Física, PPGFis, Universidade Federal do Rio Grande do Sul, UFRGS, Porto Alegre, RS (Brazil); Hinrichs, Ruth [PPGFis and Instituto de Geociências, UFRGS (Brazil); Vasconcellos, Marcos A.Z. [PPGFis and Instituto de Física, UFRGS (Brazil)

    2015-12-15

    Proton induced K-shell ionization cross sections were obtained for the elements Al, Si, Ti, Fe, and Ni in the 0.7–2.0 MeV energy range. The accuracy of these fundamental parameters is essential for PIXE analysis and the data in the literature present a considerable spread, mainly for Al and Si. The values obtained for Ti, Fe and Ni are compatible with the current theories and the experimental results reported in the literature. However, Al and Si cross sections present important differences from theoretical and experimental data. We propose values for the fluorescent yields of Al and Si that are compatible with recent results and can be incorporated in the computations of K X-ray production cross sections.

  8. 1.4MeV-5MeV中子诱发238U裂变产额测量%Fission Product Yield Measurement of 238 U Induced by 1.4-5 MeV Neutrons

    Institute of Scientific and Technical Information of China (English)

    李映映; 肖军; 王攀; 李子越; 汪超; 罗小兵

    2016-01-01

    238 U fission yield measurement has a significant meaning in nuclear data measurement .This thesis a-dopts1.4 MeV-5 MeV mono -energetic neutrons generated by 2.5 MeV proton electrostatic accelerator to stimulate 238U fission, and then measures the yield of fission product nuclide 135I、133I、105Ru and 91Sr through measuring fission product radioactivity .Neutron flux during irradiation process is determined by activation meth-od .Subsequently , this thesis analyzes multiple components influencing experiment measurement , including cor-rection on neutron′s multiple scattering and self -shielding effect in target head and sample on the basis of MC-NPX program as well as correction on sample′s self-absorption of γ-ray.Typical deviation of yield data is concluded as 3.5%.Finally, this thesis compares measurement consequences with existing fission yield data .%238 U裂变产额测量工作在核数据测量中有着重要意义,本工作利用2.5MeV质子静电加速器产生的1.4MeV-5MeV单能中子诱发238 U裂变,通过对裂变产物放射性的测量对裂变产物核素135 I、133 I、105 Ru和91 Sr的产额进行了测定。照射过程中中子通量用活化法确定。分析了影响实验测量的多个因素,包括用MCNPX程序对中子在靶头及样品中的多次散射和自屏蔽效应进行了修正,对γ射线在样品中的自吸收进行修正等。得到产额数据典型误差为3.5%,最后把测量结果与已有的裂变产额数据进行比对。

  9. Using Gas Chromatography/Isotope Ratio Mass Spectrometry to Determine the Fractionation Factor for H2 Production by Hydrogenases

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Hui; Ghandi, H.; Shi, Liang; Kreuzer, Helen W.; Ostrom, Nathaniel; Hegg, Eric L.

    2012-01-15

    Hydrogenases catalyze the reversible formation of H2, and they are key enzymes in the biological cycling of H2. H isotopes should be a very useful tool in quantifying proton trafficking in biological H2 production processes, but there are several obstacles that have thus far limited the use of this tool. In this manuscript, we describe a new method that overcomes some of these barriers and is specifically designed to measure isotopic fractionation during enzyme-catalyzed H2 evolution. A key feature of this technique is that purified hydrogenases are employed, allowing precise control over the reaction conditions and therefore a high level of precision. A custom-designed high-throughput gas chromatography-isotope ratio mass spectrometer is employed to measure the isotope ratio of the H2. Using this method, we determined that the fractionation factor of H2 production by the [NiFe]-hydrogenase from Desulfivibrio fructosovran is 0.27. This result indicates that, as expected, protons are highly favored over deuterons during H2 evolution. Potential applications of this new method are discussed.

  10. Partitioning of evapotranspiration using a stable isotope technique in an arid and high temperature agricultural production system

    KAUST Repository

    Lu, Xuefei

    2016-08-22

    Agricultural production in the hot and arid low desert systems of southern California relies heavily on irrigation. A better understanding of how much and to what extent irrigated water is transpired by crops relative to being lost through evaporation would improve the management of increasingly limited water resources. In this study, we examined the partitioning of evapotranspiration (ET) over a field of forage sorghum (Sorghum bicolor), which was under evaluation as a potential biofuel feedstock, based on isotope measurements of three irrigation cycles at the vegetative stage. This study employed customized transparent chambers coupled with a laser-based isotope analyzer to continuously measure near-surface variations in the stable isotopic composition of evaporation (E, δ), transpiration (T, δ) and ET (δ) to partition the total water flux. Due to the extreme heat and aridity, δ and δ were very similar, which makes this system highly unusual. Contrary to an expectation that the isotopic signatures of T, E, and ET would become increasingly enriched as soils became drier, our results showed an interesting pattern that δ, δ, and δ increased initially as soil water was depleted following irrigation, but decreased with further soil drying in mid to late irrigation cycle. These changes are likely caused by root water transport from deeper to shallower soil layers. Results indicate that about 46% of the irrigated water delivered to the crop was used as transpiration, with 54% lost as direct evaporation. This implies that 28 − 39% of the total source water was used by the crop, considering the typical 60 − 85% efficiency of flood irrigation. The stable isotope technique provided an effective means of determining surface partitioning of irrigation water in this unusually harsh production environment. The results suggest the potential to further minimize unproductive water losses in these production systems.

  11. Source Term Estimates of Radioxenon Released from the BaTek Medical Isotope Production Facility Using External Measured Air Concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Eslinger, Paul W.; Cameron, Ian M.; Dumais, Johannes R.; Imardjoko, Yudi; Marsoem, Pujadi; McIntyre, Justin I.; Miley, Harry S.; Stoehlker, Ulrich; Widodo, Susilo; Woods, Vincent T.

    2015-10-01

    Abstract Batan Teknologi (BaTek) operates an isotope production facility in Serpong, Indonesia that supplies 99mTc for use in medical procedures. Atmospheric releases of Xe-133 in the production process at BaTek are known to influence the measurements taken at the closest stations of the International Monitoring System (IMS). The purpose of the IMS is to detect evidence of nuclear explosions, including atmospheric releases of radionuclides. The xenon isotopes released from BaTek are the same as those produced in a nuclear explosion, but the isotopic ratios are different. Knowledge of the magnitude of releases from the isotope production facility helps inform analysts trying to decide whether a specific measurement result came from a nuclear explosion. A stack monitor deployed at BaTek in 2013 measured releases to the atmosphere for several isotopes. The facility operates on a weekly cycle, and the stack data for June 15-21, 2013 show a release of 1.84E13 Bq of Xe-133. Concentrations of Xe-133 in the air are available at the same time from a xenon sampler located 14 km from BaTek. An optimization process using atmospheric transport modeling and the sampler air concentrations produced a release estimate of 1.88E13 Bq. The same optimization process yielded a release estimate of 1.70E13 Bq for a different week in 2012. The stack release value and the two optimized estimates are all within 10 percent of each other. Weekly release estimates of 1.8E13 Bq and a 40 percent facility operation rate yields a rough annual release estimate of 3.7E13 Bq of Xe-133. This value is consistent with previously published estimates of annual releases for this facility, which are based on measurements at three IMS stations. These multiple lines of evidence cross-validate the stack release estimates and the release estimates from atmospheric samplers.

  12. Excitation functions of 124Te(d,xn)124,125I reactions from threshold up to 14 MeV: comparative evaluation of nuclear routes for the production of 124I.

    Science.gov (United States)

    Bastian, T H; Coenen, H H; Qaim, S M

    2001-09-01

    Excitation functions of the nuclear reactions 124Te(d,xn)124-125I were measured from their respective thresholds up to 14.0 MeV via the stacked-foil technique. Thin samples were prepared by electrolytic deposition of 99.8% enriched 124Te on Ti-backing. The excitation function of the 124Te(d,n)125I reaction was measured for the first time. The present data for the 124Te(d,2n)124I reaction are by an order of magnitude higher than the literature experimental data but are in good agreement with the results of a hybrid model calculation. From the measured cross sections, integral yields of 124,125I were calculated. The energy range Ed = 14 --> 10 MeV appears to be the best compromise between 124I-yield and 1251-impurity. The calculated 124I-yield amounts to 17.5 MBq/microA h and the 125I-impurity to 1.7%. A critical evaluation of the three nuclear routes for the production of 124I, viz. 124Te(d,2n)-, 124Te(p,n)- and 125Te(p,2n)-processes, is given. The reaction studied in this work proved to be least suitable. The 124Te(p,n)-reaction gives 124I of the highest radionuclidic purity, and a small-sized cyclotron is adequate for production purposes. The 125Te(p,2n)-reaction is more suitable at a medium-sized cyclotron: the yield of 124I is four times higher than in the other two reactions but the level of 0.9% 125I-impurity is relatively high.

  13. The consequences of helium production on microstructural development in isotopically tailored ferritic alloys

    Energy Technology Data Exchange (ETDEWEB)

    Gelles, D.S. [Pacific Northwest Lab., Richland, WA (United States)

    1996-10-01

    A series of alloys have been made adding various isotopes of nickel in order to vary the production of helium during irradiation by a two step nuclear reaction in a mixed spectrum reactor. The alloys use a base composition of Fe-12Cr with an addition of 1.5% nickel, either in the form of {sup 60}Ni which produces no helium, {sup 59}Ni which produces helium at a rate of about 10 appm He/dpa, or natural nickel ({sup Nat}Ni) which provides an intermediate level of helium due to delayed development of {sup 59}Ni. Specimens were irradiated in the HFIR at Oak Ridge, TN to {approx}7 dpa at 300 and 400{degrees}C. Microstructural examinations indicated that nickel additions promote precipitation in all alloys, but the effect appears to be much stronger at 400{degrees}C than at 300{degrees}C. There is sufficient dose by 7 dpa (and with 2 appm He) to initiate void swelling in ferritic/martensitic alloys. Little difference was found between response from {sup 59}Ni and {sup Nat}Ni. Also, helium bubble development for high helium generation conditions appeared to be very different at 300 and 400{degrees}C. At 300{degrees}C, it appeared that high densities of bubbles formed whereas at 400{degrees}C, bubbles could not be identified, possibly because of the complexity of the microstructure, but more likely because helium accumulated at precipitate interfaces.

  14. A neutron booster for spallation sources--application to accelerator driven systems and isotope production

    CERN Document Server

    Galy, J; Van Dam, H; Valko, J

    2002-01-01

    One can design a critical system with fissile material in the form of a thin layer on the inner surface of a cylindrical neutron moderator such as graphite or beryllium. Recently, we have investigated the properties of critical and near critical systems based on the use of thin actinide layers of uranium, plutonium and americium. The thickness of the required fissile layer depends on the type of fissile material, its concentration in the layer and on the geometrical arrangement, but is typically in the mu m-mm range. The resulting total mass of fissile material can be as low as 100 g. Thin fissile layers have a variety of applications in nuclear technology--for example in the design neutron amplifiers for medical applications and 'fast' islands in thermal reactors for waste incineration. In the present paper, we investigate the properties of a neutron booster unit for spallation sources and isotope production. In those applications a layer of fissile material surrounds the spallation source. Such a module cou...

  15. Daily cortisol production rate in man determined by stable isotope dilution/mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Esteban, N.V.; Loughlin, T.; Yergey, A.L.; Zawadzki, J.K.; Booth, J.D.; Winterer, J.C.; Loriaux, D.L. (National Institute of Child Health and Human Development, Bethesda, MD (USA))

    1991-01-01

    Growth retardation as well as the development of Cushingoid features in adrenally insufficient patients treated with the currently accepted replacement dose of cortisol (33-41 mumol/day.m2; 12-15 mg/m2.day) prompted us to reevaluate the cortisol production rate (FPR) in normal subjects and patients with Cushing's syndrome, using a recently developed thermospray liquid chromatography-mass spectrometry method. The stable isotope (9,12,12-2H3)cortisol was infused continuously for 31 h at about 5% of the anticipated FPR. Blood samples were obtained at 20-min intervals for 24 h, spun, and pooled in 4-h groups. Tracer dilution in plasma was determined by liquid chromatography/mass spectrometry. The method was validated with controlled infusions in 6 patients with adrenal insufficiency. Results from 12 normal volunteers revealed a FPR of 27.3 +/- 7.5 mumol/day (9.9 +/- 2.7 mg/day) or 15.7 mumol/day.m2; 5.7 mg/m2. day. A previously unreported circadian variation in FPR was observed. Patients with Cushing's syndrome demonstrated unequivocal elevation of FPR and cortisol concentration correlated during each sample period in normal volunteers, indicating that cortisol secretion, rather than metabolism, is mainly responsible for changes in plasma cortisol. Our data suggest that the FPR in normal subjects may be lower than previously believed.

  16. Deuteron-induced reactions generated by intense lasers for PET isotope production

    Science.gov (United States)

    Kimura, Sachie; Bonasera, Aldo

    2011-05-01

    We investigate the feasibility of using laser accelerated protons/deuterons for positron emission tomography (PET) isotope production by means of the nuclear reactions 11B(p, n) 11C and 10B(d, n) 11C. The second reaction has a positive Q-value and no energy threshold. One can, therefore, make use of the lower energy part of the laser-generated deuterons, which includes the majority of the accelerated deuterons. By assuming that the deuteron spectra are similar to the proton spectra, the 11C produced from the reaction 10B(d, n) 11C is estimated to be 7.4×10 9 per laser-shot at the Titan laser at Lawrence Livermore National Laboratory. Meanwhile a high-repetition table-top laser irradiation is estimated to generate 3.5×10 711C per shot from the same reaction. In terms of the 11C activity, it is about 2×10 4 Bq per shot. If this laser delivers kHz, the activity is integrated to 1 GBq after 3 min. The number is sufficient for the practical application in medical imaging for PET.

  17. Deuteron-induced reactions generated by intense Lasers for PET isotope production

    CERN Document Server

    Kimura, Sachie

    2011-01-01

    We investigate the feasibility of using laser accelerated protons/deuterons for positron emission tomography (PET) isotope production by means of the nuclear reactions $^{11}$B($p,n$)$^{11}$C and $^{10}$B($d,n$)$^{11}$C. The second reaction has a positive Q-value and no energy threshold. One can, therefore, make use of the lower energy part of the laser-generated deuterons, which includes the majority of the accelerated deuterons. The $^{11}$C produced from the reaction $^{10}$B($d,n$)$^{11}$C is estimated to be 7.4 $\\times$ 10$^{9}$ per laser-shot at the Titan laser at Lawrence Livermore National Laboratory. Meanwhile a high-repetition table top laser irradiation is estimated to generate 3.5 $\\times$ 10$^7$ $^{11}$C per shot from the same reaction. In terms of the $^{11}$C activity, it is about 2 $\\times$ 10$^4$ Bq per shot. If this laser delivers kHz, the activity is integrated to 1 GBq after 3 minutes. The number is sufficient for the practical application in medical imaging for PET.

  18. 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 ...

  19. Sulfur Isotope Trends in Archean Microbialite Facies Record Early Oxygen Production and Consumption

    Science.gov (United States)

    Zerkle, A.; Meyer, N.; Izon, G.; Poulton, S.; Farquhar, J.; Claire, M.

    2014-12-01

    The major and minor sulfur isotope composition (δ34S and Δ33S) of pyrites preserved in ~2.65-2.5 billion-year-old (Ga) microbialites record localized oxygen production and consumption near the mat surface. These trends are preserved in two separate drill cores (GKF01 and BH1-Sacha) transecting the Campbellrand-Malmani carbonate platform (Ghaap Group, Transvaal Supergroup, South Africa; Zerkle et al., 2012; Izon et al., in review). Microbialite pyrites possess positive Δ33S values, plotting parallel to typical Archean trends (with a Δ33S/δ34S slope of ~0.9) but enriched in 34S by ~3 to 7‰. We propose that these 34S-enriched pyrites were formed from a residual pool of sulfide that was partially oxidized via molecular oxygen produced by surface mat-dwelling cyanobacteria. Sulfide, carrying the range of Archean Δ33S values, could have been produced deeper within the microbial mat by the reduction of sulfate and elemental sulfur, then fractionated upon reaction with O2 produced by oxygenic photosynthesis. Preservation of this positive 34S offset requires that: 1) sulfide was only partially (50­­-80%) consumed by oxidation, meaning H2S was locally more abundant (or more rapidly produced) than O2, and 2) the majority of the sulfate produced via oxidation was not immediately reduced to sulfide, implying either that the sulfate pool was much larger than the sulfide pool, or that the sulfate formed near the mat surface was transported and reduced in another part of the system. Contrastingly, older microbialite facies (> 2.7 Ga; Thomazo et al., 2013) appear to lack these observed 34S enrichments. Consequently, the onset of 34S enrichments could mark a shift in mat ecology, from communities dominated by anoxygenic photosynthesizers to cyanobacteria. Here, we test these hypotheses with new spatially resolved mm-scale trends in sulfur isotope measurements from pyritized stromatolites of the Vryburg Formation, sampled in the lower part of the BH1-Sacha core. Millimeter

  20. Isotope reversals in hydrocarbon gases of natural shale systems and well head production data

    Energy Technology Data Exchange (ETDEWEB)

    Berner, U.; Schloemer, S.; Stiller, E. [Bundesanstalt fuer Geowissenschaften und Rohstoffe (BGR), Hannover (Germany); Marquardt, D. [Rijksuniversiteit Utrecht (Netherlands)

    2013-08-01

    Relationships between gas geochemical signatures and the thermal maturity of source rocks containing aquatic organic matter are based on on pyrolysis experiments and have been successfully used in conventional hydrocarbon exploration since long. We demonstrate how these models can be applied to the evaluation of unconventional shale resources. For this purpose hydrocarbon gases have been extracted from low and high mature source rocks (type II kerogens) using laboratory desorption techniques. We determined the molecular composition of the gases as well as the carbon isotope ratios of methane to propane. In the extracted gases we observe an increase of {sup 13}C content in methane with increasing dry gas ratio (C1/{Sigma}C1-6). The carbon isotope ratios of ethane and propane initially increase with increasing dryness but start to become isotopically lighter above a dry gas ratio of 0.8. We show that oil-to-gas cracking explains the observed gas geochemical data, and that mixing between gases from different processes is a key factor to describe natural hydrocarbon systems of shales. However, data from published case studies using well head gases which show 'isotope roll-over' effects indicate that the isotopic reversal observed in well head samples deviate from those observed in natural shale systems in a fundamental way. We show that isotope reversals related to well head gases are best explained by an additional isotope fractionation effect induced through hydraulic fracturing and gas migration from the shale to the well head. Although, this induced isotope fractionation is an artifact which obscures isotopic information of natural systems to a large extend, we suggest a simple classification scheme which allows distinguishing between hot and cool spot areas using well head or mud line gas data. (orig.)

  1. A unified nucleosynthetic site for the production of heavy isotopes and p-nuclei

    CERN Document Server

    Ouyed, Amir; Leahy, Denis

    2014-01-01

    Current r-process models under-produce A130 nuclei, and spallation fragments these isotopes into A<130 nuclei and all 35 p-nuclei. Our model is universal in relation to a star's age, metallicity, and chemistry.

  2. Investigation of isotopic linkages between precursor materials and the improvised high explosive product hexamethylene triperoxide diamine

    NARCIS (Netherlands)

    Lock, C.M.; Brust, G.M.H.; Breukelen, M. van; Dalmolen, J.; Koeberg, M.; Stoker, D.A.

    2012-01-01

    The results of isotope ratio mass spectrometry (IRMS) on hexamethylene triperoxide diamine (HMTD) and its precursor hexamethylenetetramine (hexamine) is presented. HMTD was prepared from hexamine using several different sources of hexamine under both controlled laboratory conditions and in field exp

  3. Computer analyses for the design, operation and safety of new isotope production reactors: A technology status review

    Energy Technology Data Exchange (ETDEWEB)

    Wulff, W.

    1990-01-01

    A review is presented on the currently available technologies for nuclear reactor analyses by computer. The important distinction is made between traditional computer calculation and advanced computer simulation. Simulation needs are defined to support the design, operation, maintenance and safety of isotope production reactors. Existing methods of computer analyses are categorized in accordance with the type of computer involved in their execution: micro, mini, mainframe and supercomputers. Both general and special-purpose computers are discussed. Major computer codes are described, with regard for their use in analyzing isotope production reactors. It has been determined in this review that conventional systems codes (TRAC, RELAP5, RETRAN, etc.) cannot meet four essential conditions for viable reactor simulation: simulation fidelity, on-line interactive operation with convenient graphics, high simulation speed, and at low cost. These conditions can be met by special-purpose computers (such as the AD100 of ADI), which are specifically designed for high-speed simulation of complex systems. The greatest shortcoming of existing systems codes (TRAC, RELAP5) is their mismatch between very high computational efforts and low simulation fidelity. The drift flux formulation (HIPA) is the viable alternative to the complicated two-fluid model. No existing computer code has the capability of accommodating all important processes in the core geometry of isotope production reactors. Experiments are needed (heat transfer measurements) to provide necessary correlations. It is important for the nuclear community, both in government, industry and universities, to begin to take advantage of modern simulation technologies and equipment. 41 refs.

  4. Experimental deuteron cross section measurements using single natural titanium foils from 3 to 9 MeV with special reference to the production of {sup 47}V and {sup 51}Ti

    Energy Technology Data Exchange (ETDEWEB)

    Gagnon, K., E-mail: kgagnon@phys.ualberta.c [Edmonton PET Centre, Cross Cancer Institute, University of Alberta, 11560 University Avenue, Edmonton, Alberta, T6G 1Z2 (Canada); Avila-Rodriguez, M.A. [Unidad PET/CT-Ciclotron, Facultad de Medicina, Universidad Nacional Autonoma de Mexico, Edificio de Investigacion P.B., Cd. Universitaria, Circ. Interior, C.P. 04510, Mexico D.F. (Mexico); Wilson, J.; McQuarrie, S.A. [Edmonton PET Centre, Cross Cancer Institute, University of Alberta, 11560 University Avenue, Edmonton, Alberta, T6G 1Z2 (Canada)

    2010-05-01

    Although the conventional stacked foil technique is the common method for evaluating experimental cross sections of deuteron induced reactions on titanium, this work employed a single foil irradiation strategy. This strategy was selected for the purpose of improving the counting statistics for the reactions with low activation probabilities as it allowed for activity assay times comparable to the half-life of the product of interest. Given a single detector, similar activity assay times were not possible for the stacked foil technique as all remaining foils would have otherwise decayed significantly while the first foil was counting. To the best of our knowledge, this work reports the first comprehensive study of the elemental cross sections for production of {sup 47}V (t{sub 1/2} = 32.6 m) and {sup 51}Ti (t{sub 1/2} = 5.76 m) for 3-9 MeV deuterons on natural titanium foil. Elemental cross sections for the production of {sup 44g,44m,46,47,48}Sc, and {sup 48}V were also evaluated, with good agreement to previous literature generally observed.

  5. The influence of cloud droplet heterogeneity on sulfate production mechanisms constrained by isotopic measurements of sulfate aerosol

    Science.gov (United States)

    Alexander, B.; Allman, D. J.; Amos, H. M.; Fairlie, T. D.; Dachs, J.; Hegg, D.; Sletten, R. S.

    2011-12-01

    Observations and modeling studies have shown that heterogeneity in fog and cloud drop size and chemical composition can significantly impact in-cloud sulfate production rates due to the strong pH dependence of the ozone oxidation pathway. Averaging cloud water pH tends to underestimate the fraction of S(IV) that is SO32- leading to underestimates of in-cloud sulfate production rates. Large scale models typically do not account for this heterogeneity due to the large computational expense associated with this calculation, and instead employ bulk calculations or assumptions of cloud water pH. Modeling studies have consistently shown that calculated sulfate production rates using bulk cloud pH treatments tend to underestimate in-cloud sulfate production rates compared to more explicit treatment of cloud drop heterogeneity by underestimating the ozone oxidation pathway. Here, we utilize a global chemical transport model (GEOS-Chem) and observations of the oxygen isotopic composition of sulfate aerosol collected during a ship cruise in the subtropical northeast Atlantic Ocean to quantify sulfate formation pathways in the marine boundary layer. The oxygen isotopic composition of sulfate aerosol is particularly sensitive to the importance of the ozone oxidation pathway due to its large isotopic signature. We employ a model parameterization by Yuen et al. (1996) that accounts for the impact of alkaline, coarse-mode sea salt aerosols on in-cloud sulfate production rates. As sulfate formation in cloud droplets formed on alkaline coarse-mode sea salt aerosols is thought to be dominated by the ozone oxidation pathway, observations of the oxygen isotopic composition of sulfate aerosol provide a robust test of this parameterization. Including the Yuen et al. (1996) parameterization of cloud droplet heterogeneity improves the model's agreement with the observed sulfate oxygen isotopes. Accounting for the impact of cloud droplet heterogeneity on in-cloud sulfate production rates

  6. Thermal Safety Analyses for the Production of Plutonium-238 at the High Flux Isotope Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Hurt, Christopher J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Freels, James D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hobbs, Randy W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jain, Prashant K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Maldonado, G. Ivan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-08-01

    There has been a considerable effort over the previous few years to demonstrate and optimize the production of plutonium-238 (238Pu) at the High Flux Isotope Reactor (HFIR). This effort has involved resources from multiple divisions and facilities at the Oak Ridge National Laboratory (ORNL) to demonstrate the fabrication, irradiation, and chemical processing of targets containing neptunium-237 (237Np) dioxide (NpO2)/aluminum (Al) cermet pellets. A critical preliminary step to irradiation at the HFIR is to demonstrate the safety of the target under irradiation via documented experiment safety analyses. The steady-state thermal safety analyses of the target are simulated in a finite element model with the COMSOL Multiphysics code that determines, among other crucial parameters, the limiting maximum temperature in the target. Safety analysis efforts for this model discussed in the present report include: (1) initial modeling of single and reduced-length pellet capsules in order to generate an experimental knowledge base that incorporate initial non-linear contact heat transfer and fission gas equations, (2) modeling efforts for prototypical designs of partially loaded and fully loaded targets using limited available knowledge of fabrication and irradiation characteristics, and (3) the most recent and comprehensive modeling effort of a fully coupled thermo-mechanical approach over the entire fully loaded target domain incorporating burn-up dependent irradiation behavior and measured target and pellet properties, hereafter referred to as the production model. These models are used to conservatively determine several important steady-state parameters including target stresses and temperatures, the limiting condition of which is the maximum temperature with respect to the melting point. The single pellet model results provide a basis for the safety of the irradiations, followed by parametric analyses in the initial prototypical designs

  7. Stable Isotope and Isotopomeric Constraints on Nitrous Oxide Production in a Wastewater Treatment Plant

    Science.gov (United States)

    Bellucci, F.; Gonzalez-Meler, M. A.; Sturchio, N. C.; Bohlke, J. K.; Ostrom, N. E.; Kozak, J. A.

    2011-12-01

    Estimates of US anthropogenic greenhouse gas emissions by USEPA (Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2009; 2011) indicate that wastewater treatment plants are the 7th highest contributor to atmospheric nitrous oxide. This unregulated gas has an estimated global warming potential (GWP) 310 times that of carbon dioxide on a per mol basis. There is general agreement that, within wastewater treatment plants, the vast majority of the nitrous oxide emissions occur in the aerobic zones for biological ammonia oxidation and/or downstream from anoxic zones used in biological nitrogen removal. However, the exact mechanism of production is not well understood, as both incomplete nitrification and denitrification might contribute to the overall nitrous oxide emissions. Determining the dominant biological pathways responsible for these emissions is important for the development of improved treatment systems that can reduce nitrous oxide greenhouse gas emissions to the atmosphere. In this study, we determined the total nitrous oxide flux from a single tank of one of the aeration basins from a large metropolitan wastewater treatment plant in Stickney, Illinois. Furthermore, we analyzed the changes in nitrogen and oxigen stable isotopic composition for ammonium, nitrate, and nitrous oxide, as well as the intramolecular site preference (SP) for δ15N within the linear N-N-O molecule, along the 520 meter wastewater flow path within the tank. Assuming the measured tank was representative of the 32 tanks constituting the 4 aeration basins of the plant, we estimate the combined annual nitrous oxide flux from this source to be approximately 230 metric ton/y. The δ15N values for ammonium ranged between +19.9% and +6.4%, those for nitrate ranged between +20.4% and +5.3%, and those for nitrous oxide ranged between -34.4% and 0.4%. The nitrous oxide SP ranged between +11.7% and -4.5%. The concentrations and δ15N values of ammonium and nitrate showed trends along the

  8. Titanium-II: an evaluated nuclear data file. [E < 20. 0 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Philis, C.; Howerton, R.; Smith, A.B.

    1977-06-01

    A comprehensive evaluated nuclear data file for elemental titanium is outlined including definition of the data base, the evaluation procedures and judgments, and the final evaluated results. The file describes all significant neutron-induced reactions with elemental titanium and the associated photon-production processes to incident neutron energies of 20.0 MeV. In addition, isotopic-reaction files, consistent with the elemental file, are separately defined for those processes which are important to applied considerations of material-damage and neutron-dosimetry. The file is formulated in the ENDF format. This report formally documents the evaluation and, together with the numerical file, is submitted for consideration as a part of the ENDF/B-V evaluated file system. 20 figures, 9 tables.

  9. Central region design for a 10 MeV internal ion source cyclotron

    Institute of Scientific and Technical Information of China (English)

    QIN Bin; LIU Kai-Feng; FENG Yi-Zhang; FAN Ming-Wu

    2009-01-01

    Internal ion sources are widely adopted in commercial cyclotrons used for short-life isotopes produc-tion. Without beam manipulation provided by the external beam injection line, the central region of this type of cyclotron is more sensitive and should be carefully designed. A design study and beam dynamics simulation for the central region of a 10 MeV compact cyclotron is presented. The OPERA3D/TOSCA code was used to calculate the electric field from a parameterized three dimensional (3D) central region model. With iterative structure optimizations of the central region, the beam centering and vertical focusing is well controlled, and the RF phase acceptance is around 25° A c++ code for beam simulation in the central region was developed and tested.

  10. Photonuclear activation of pure isotopic mediums.

    Energy Technology Data Exchange (ETDEWEB)

    Grohman, Mark A.; Lukosi, Eric Daniel

    2010-06-01

    This work simulated the response of idealized isotopic U-235, U-238, Th-232, and Pu-239 mediums to photonuclear activation with various photon energies. These simulations were conducted using MCNPX version 2.6.0. It was found that photon energies between 14-16 MeV produce the highest response with respect to neutron production rates from all photonuclear reactions. In all cases, Pu-239 responds the highest, followed by U-238. Th-232 produces more overall neutrons at lower photon energies then U-235 when material thickness is above 3.943 centimeters. The time it takes each isotopic material to reach stable neutron production rates in time is directly proportional to the material thickness and stopping power of the medium, where thicker mediums take longer to reach stable neutron production rates and thinner media display a neutron production plateau effect, due to the lack of significant attenuation of the activating photons in the isotopic mediums. At this time, no neutron sensor system has time resolutions capable of verifying these simulations, but various indirect methods are possible and should be explored for verification of these results.

  11. Production of intense metallic ion beams in order of isotopic separations; Production de faisceaux intenses d'ions metalliques en vue de la separation des isotopes

    Energy Technology Data Exchange (ETDEWEB)

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

    1955-07-01

    We describe an isotope separator with magnetic sector of 60 deg that permits, with a process of neutralization of the space charge, to use efficiently intense ion beams. The sources of realized ions provide ionic debits of 10 mA. This present work deals who to obtain intense ion beams (10 to 15 mA), different processes of ion currents measurement, as well as the study of the phenomenon of space charge neutralization. The second part of this memory will be on the survey and the adaptation on the source of various type of oven permitting to spray and to ionize metals directly. By order of increasing difficulty of vaporization, we reached the chromium. (M.B.) [French] 0n decrit un separateur d'isotope a secteur magnetique de 60 deg qui permet, grace a un procede de neutralisation de la charge d'espace, d'utiliser efficacement des faisceaux d'ions intenses. Les sources d'ions realisees fournissent des debits ioniques de 10 mA. Ce present travail porte sur l'obtention de faisceaux d'ions faisceaux d'ions intenses (10 a 15 mA), des differents procedes de mesures des courants d'ions, ainsi que l'etude du phenomene de neutralisation de charge d'espace. La deuxieme partie de ce memoire portera sur l'etude et l'adaptation sur la source de divers type de four permettant de vaporiser et d'ioniser directement les metaux. Par ordre de difficulte croissantes de vaporisations, nous avons atteint le chrome. (M.B.)

  12. Production of intense metallic ion beams in order of isotopic separations; Production de faisceaux intenses d'ions metalliques en vue de la separation des isotopes

    Energy Technology Data Exchange (ETDEWEB)

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

    1955-07-01

    We describe an isotope separator with magnetic sector of 60 deg that permits, with a process of neutralization of the space charge, to use efficiently intense ion beams. The sources of realized ions provide ionic debits of 10 mA. This present work deals who to obtain intense ion beams (10 to 15 mA), different processes of ion currents measurement, as well as the study of the phenomenon of space charge neutralization. The second part of this memory will be on the survey and the adaptation on the source of various type of oven permitting to spray and to ionize metals directly. By order of increasing difficulty of vaporization, we reached the chromium. (M.B.) [French] 0n decrit un separateur d'isotope a secteur magnetique de 60 deg qui permet, grace a un procede de neutralisation de la charge d'espace, d'utiliser efficacement des faisceaux d'ions intenses. Les sources d'ions realisees fournissent des debits ioniques de 10 mA. Ce present travail porte sur l'obtention de faisceaux d'ions faisceaux d'ions intenses (10 a 15 mA), des differents procedes de mesures des courants d'ions, ainsi que l'etude du phenomene de neutralisation de charge d'espace. La deuxieme partie de ce memoire portera sur l'etude et l'adaptation sur la source de divers type de four permettant de vaporiser et d'ioniser directement les metaux. Par ordre de difficulte croissantes de vaporisations, nous avons atteint le chrome. (M.B.)

  13. Continuous flow stable isotope methods for study of δ13C fractionation during halomethane production and degradation

    Science.gov (United States)

    Kalin, Robert M.; Hamilton, John T.G.; Harper, David B.; Miller, Laurence G.; Lamb, Clare; Kennedy, James T.; Downey, Angela; McCauley, Sean; Goldstein, Allen H.

    2001-01-01

    Gas chromatography/mass spectrometry/isotope ratio mass spectrometry (GC/MS/IRMS) methods for δ13C measurement of the halomethanes CH3Cl, CH3Br, CH3I and methanethiol (CH3SH) during studies of their biological production, biological degradation, and abiotic reactions are presented. Optimisation of gas chromatographic parameters allowed the identification and quantification of CO2, O2, CH3Cl, CH3Br, CH3I and CH3SH from a single sample, and also the concurrent measurement of δ13C for each of the halomethanes and methanethiol. Precision of δ13C measurements for halomethane standards decreased (±0.3, ±0.5 and ±1.3‰) with increasing mass (CH3Cl, CH3Br, CH3I, respectively). Given that carbon isotope effects during biological production, biological degradation and some chemical (abiotic) reactions can be as much as 100‰, stable isotope analysis offers a precise method to study the global sources and sinks of these halogenated compounds that are of considerable importance to our understanding of stratospheric ozone destruction. 

  14. Geogenic lead isotope signatures from meat products in Great Britain: Potential for use in food authentication and supply chain traceability

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Jane A.; Pashley, Vanessa [NIGL, BGS, Keyworth, NG12 5GG (United Kingdom); Richards, Gemma J. [School of Veterinary Science, University of Bristol, Bristol BS40 5DU (United Kingdom); Brereton, Nicola [The Food and Environment Research Agency, Sand Hutton, York YO41 1LZ (United Kingdom); Knowles, Toby G. [School of Veterinary Science, University of Bristol, Bristol BS40 5DU (United Kingdom)

    2015-12-15

    This paper presents lead (Pb) isotope data from samples of farm livestock raised in three areas of Britain that have elevated natural Pb levels: Central Wales, the Mendips and the Derbyshire Peak District. This study highlights three important observations; that the Pb found in modern British meat from these three areas is geogenic and shows no clear evidence of modern tetraethyl anthropogenic Pb contribution; that the generally excellent match between the biological samples and the ore field data, particularly for the Mendip and Welsh data, suggests that this technique might be used to provenance biological products to specific ore sites, under favourable conditions; and that modern systems reflect the same process of biosphere averaging that is analogous to cultural focusing in human archaeological studies that is the process of biological averaging leading to an homogenised isotope signature with increasing Pb concentration. - Highlights: • Lead (Pb) isotopes measured in modern British meat were geogenic in origin. • The match indicates that this technique may be used to provenance biological products. • There was no evidence for a contribution from modern anthropogenic Pb sources.

  15. Neutron Production in Coincidence with Fragments from the {sup 40}Ca + H Reactions at E{sub lab} = 357 and 565 A MeV

    Energy Technology Data Exchange (ETDEWEB)

    Tuve, C.; Albergo, S.; Boemi, D.; Caccia, Z.; Chen, C.-X.; Costa, S.; Crawford, H.J.; Cronqvist, M.; Engelage, J.; Greiner, L.; Guzik, T.G.; Insolia, A.; Knott, C.N.; Lindstrom, P.J.; Mitchell, J.W.; Potenza, R.; Russo, G.V.; Soutoul, A.; Testard, O.; Tricomi, A.; Tull, C.E.; Waddington, C.J.; Webber, W.R.; Wefel, J.P.

    2000-12-31

    In the frame of the Transport Collaboration neutrons in coincidence with charged fragments produced in the {sup 40}Ca + H reaction at E{sub lab} = 357 and 565 AMeV have been measured at the Heavy Ion Spectrometer System (HISS) facility of the Lawrence Berkeley National Laboratory, using the multifunctional neutron spectrometer MUFFINS. The detector covered a narrow angular range about the beam in the forward direction (0? - 3.2?). In this contribution we report absolute neutron production cross sections in coincidence with charged fragments (10 {<=} Z {<=} 20). The neutron multiplicities have been estimated from the comparison between the neutron cross sections, in coincidence with the fragments, and the elemental cross sections. We have found evidence for a pre-equilibrium emission of prompt neutrons in superposition to a 'slower' deexcitation of the equilibrated remnant by emission of nucleons and fragments, as already seen in the inclusive rapidity distributions.

  16. Congener-specific concentrations and carbon stable isotope ratios (delta13C) of two technical toxaphene products (Toxaphene and Melipax).

    Science.gov (United States)

    Vetter, Walter; Gleixner, Gerd; Armbruster, Wolfgang; Ruppe, Steffen; Stern, Gary A; Braekevelt, Eric

    2005-01-01

    In this study we compared the contribution of individual congeners and the ratios of stable carbon isotopes of two technical toxaphene products. The former US-American product Toxaphene was from 1978 and the East-German product Melipax from 1979. Both technical products showed the known complexity in GC/ECD measurements. Contributions of 24 peaks to each of the technical products were determined by gas chromatography in combination high resolution electron capture negative ion mass spectrometry (GC/ECNI-HRMS). The percentages of the compounds studied in the technical mixtures ranged from approximately 0.05% to approximately 2.5% but showed some individual differences. 2,2,5,5,8,9,9,10,10-nonachlorobornane (B9-1025 or P-62) was identified as a major congener in both mixtures. 2-Endo,3-exo,5-endo,6-exo,8,8,10,10-octachlorobornane (B8-1413 or P26) and 2-endo,3-exo,5-endo,6-exo,8,8,9,10,10-nonachlorobornane (B9-1679 or P-50) were found at similar concentration in both technical products. Identical amounts of Melipax or Toxaphene were combusted to CO2 in an element analyzer and their delta13C values were determined relative to the international standard Vienna PeeDee belemnite (VPDB). The mean delta13C values of both products varied by 2.8% (determined at two different locations) which is roughly one order of magnitude more than the precision obtained in repetitive analyses of the individual products. Thus, both investigated products could be unequivocally distinguished by stable isotope ratio mass spectrometry (IRMS). IRMS analyses may thus be a suitable tool for tracing back toxaphene residues in environmental and food samples to the one or both of the products.

  17. Characterizing isotopic variability of primary production and consumers in Great Plains ecosystems during protracted regional drought

    Science.gov (United States)

    Haveles, A. W.; Fox-Dobbs, K.; Talmadge, K. A.; Fetrow, A.; Fox, D. L.

    2012-12-01

    Over the last few years (2010-2012), the Great Plains of the central USA experienced protracted drought conditions, including historically severe drought during Summer, 2011. Drought severity in the region generally decreases with increasing latitude, but episodic drought is a fundamental trait of grassland ecosystems. Documenting above ground energy and nutrient flow with current drought is critical to understanding responses of grassland ecosystems in the region to predicted increased episodicity of rainfall and recurrence of drought due to anthropogenic climate change. Characterization of biogeochemical variability of modern ecosystems at the microhabitat, local landscape, and regional scales is also necessary to interpret biogeochemical records of ancient grasslands based on paleosols and fossil mammals. Here, we characterize three grassland ecosystems that span the drought gradient in the Great Plains (sites in the Texas panhandle, southwest Kansas, and northwest Nebraska). We measured δ13C and δ15N values of plants and consumers to characterize the biogeochemical variability within each ecosystem. Vegetation at each site is a mix of trees, shrubs, herbs, and cool- and warm-growing season grasses (C3 and C4, respectively). Thus, consumers have access to isotopically distinct sources of forage that vary in abundance with microhabitat (e.g., open grassland, shrub thicket, riparian woodland). Observations indicate herbivorous arthropod (grasshoppers and crickets) abundance follows drought severity, with high abundance of many species in Texas, and low abundance of few species in Nebraska. Small mammal (rodents) abundance follows the inverse pattern with 0.8%, 3.2% and 17.2% capture success in Texas, Kansas and Nebraska, respectively. The inverse abundance patterns of consumer groups may result from greater sensitivity of small mammal consumers with high metabolic needs to lower local net primary productivity and forage quality under drought conditions. As a

  18. An intranuclear cascade-percolation approach for protons and light fragments production in neon-niobium reactions at 400 and 800 MeV per nucleon

    Energy Technology Data Exchange (ETDEWEB)

    Montarou, G.; Marroncle, J.; Alard, J.P.; Augerat, J.; Bastid, N.; Charmensat, P.; Dupieux, P.; Fraysse, L.; Parizet, M.J.; Rahmani, A. [Clermont-Ferrand-2 Univ., 63 - Aubiere (France). Lab. de Physique Corpusculaire; Babinet, R.; Cavata, C.; Demoulins, M.; Fanet, H.; Gosset, J.; L`Hote, D.; Lucas, B.; Poitou, J.; Valette, O. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l`Instrumentation Associee; Lemaire, M.C. [Laboratoire National Saturne, Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France); Brochard, F.; Gorodetzky, P.; Racca, C. [Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires; Cugnon, J. [Liege Univ. (Belgium). Inst. de Physique

    1992-12-31

    The results of intranuclear cascade calculations (ideal gas with two body collisions and no mean-field), complemented by a simple percolation procedure, are compared with experimental data on protons and light nuclear fragments (d, t, {sup 3}He and {sup 4}He) measured in 400 and 800 MeV/nucleon Ne+Nb collisions using the large solid angle detector DIOGENE. The model reproduces quite well global experimental observables like nuclear fragment multiplicity distributions or production cross-sections, and nuclear fragment to proton ratios. For rapidity distributions the best agreement occurs for peripheral reactions. Transverse momentum analysis confirms once again that the cascade, although being a microscopic approach, gives too small a collective flow. For heavier nuclear fragments conclusions are not so clear. Since the cross-sections are the main ingredients of the detailed treatment of the first stage of the reaction by the intranuclear cascade, such an approach can be very fruitful in order to infer informations on effective nucleon-nucleon cross-sections. (authors). 31 refs., 23 figs., 6 tabs.

  19. Intranuclear cascade-percolation approach for protons and light fragments production in neon-niobium reactions at 400 and 800 MeV per nucleon

    Energy Technology Data Exchange (ETDEWEB)

    Montarou, G.; Marroncle, J.; Alard, J.P.; Augerat, J.; Bastid, N.; Charmensat, P.; Dupieux, P.; Fraysse, L.; Parizet, M.J.; Rahmani, A. (Laboratoire de Physique Corpusculaire, Universite Blaise Pascal, IN2P3-CNRS, Clermont-Ferrand, F-63177 Aubiere Cedex (France)); Babinet, R.; Cavata, C.; Demoulins, M.; Fanet, H.; Gosset, J.; L' Hote, D.; Lemaire, M.C.; Lucas, B.; Poitou, J.; Valette, O. (Service de Physique Nucleaire, DAPNIA, CE-Saclay, F-91191 Gif-sur-Yvette Cedex (France)); Brochard, F.; Gorodetzky, P.; Racca, C. (Centre de Recherches Nucleaires, 23 rue du Loess, BP 20 CR, 67037 Strasbourg (France)); Cugnon, J. (Institut de Physique, Universite de Liege, Sart Tilman, B-4000 Liege 1 (Belgium))

    1993-06-01

    The results of intranuclear cascade calculations (ideal gas with two-body collisions and no mean field), complemented by a simple percolation procedure, are compared with experimental data on protons and light nuclear fragments ([ital d], [ital t], [sup 3]He, and [sup 4]He) measured in 400 and 800 MeV/nucleon Ne+Nb collisions using a large solid angle detector. The model reproduces quite well global experimental observables like nuclear fragment multiplicity distributions or production cross sections, and nuclear fragment to proton ratios. For rapidity distributions the best agreement occurs for peripheral reactions. Transverse momentum analysis confirms once again that the cascade, although being a microscopic approach, gives too small a collective flow, the best agreement being reached for [ital Z]=2 nuclear fragments. Nevertheless these comparisons are encouraging for further improvements of the model. Moreover, such an approach is easy to extend to any other models that could calculate the nucleon phase space distribution after the compression stage of the reaction, when light nuclear fragments emitted at large angles are constructed from percolation.

  20. Production cross-sections of {sup 181-186}Re isotopes from proton bombardment of natural tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Lapi, S. [Simon Fraser University, 8888 University Drive, Burnaby BC, V5A 1S6 (Canada) and TRIUMF, Pet Group, 4004 Wesbrook Mall, Vancouver BC, V6T 2A3 (Canada)]. E-mail: slapi@sfu.ca; Mills, W.J. [Simon Fraser University, 8888 University Drive, Burnaby BC, V5A 1S6 (Canada); Wilson, J. [University of Alberta, 11560 University Avenue, Edmonton, AB, T6G 1Z2 (Canada); McQuarrie, S. [University of Alberta, 11560 University Avenue, Edmonton, AB, T6G 1Z2 (Canada); Publicover, J. [University of Victoria, 3800 Finnerty Road, Victoria, BC, V8W 5C2 (Canada); Schueller, M. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Schyler, D. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Ressler, J.J. [Simon Fraser University, 8888 University Drive, Burnaby BC, V5A 1S6 (Canada); Ruth, T.J. [Simon Fraser University, 8888 University Drive, Burnaby BC, V5A 1S6 (Canada); TRIUMF, Pet Group, 4004 Wesbrook Mall, Vancouver BC, V6T 2A3 (Canada)

    2007-03-15

    Cross-sections for the production of {sup 181}Re, {sup 182m}Re, {sup 182g}Re, {sup 183}Re, {sup 184}Re, and {sup 186}Re from proton bombardment of natural tungsten have been measured using the stacked foil technique for proton energies up to 17.6 MeV. Results are compared with the theoretical excitation functions as calculated by the EMPIRE II code (version 2.19) and experimental literature values. Results are in strong agreement with some of the previously reported literature as well at theoretical calculations for multiple reactions providing for more reliable estimates for the {sup 186}W(p, n){sup 186}Re reaction.

  1. Reply to Nicholson's comment on "Consistent calculation of aquatic gross production from oxygen triple isotope measurements" by Kaiser (2011

    Directory of Open Access Journals (Sweden)

    J. Kaiser

    2011-10-01

    Full Text Available The comment by Nicholson (2011a questions the "consistency" of the "definition" of the "biological end-member" used by Kaiser (2011a in the calculation of oxygen gross production. "Biological end-member" refers to the relative oxygen isotope ratio difference between photosynthetic oxygen and Air-O2 (abbreviated 17δP and 18δP for 17O/16O and 18O/16O, respectively.

    This comment has no merit for the following reasons: (a the isotopic composition of photosynthetic oxygen cannot be "defined", it can only be measured, modelled or calculated based on other data; (b the isotopic composition of photosynthetic oxygen was not "defined" in Kaiser (2011a, but derived from published measurements; (c the published measurements themselves were inconsistent and no single result could be identified as best; (d since no best value could be identified, a hypothetical base case was constructed in a way that was consistent with previous publications; (e the values of 17δP=−11.646‰ and 18δP=−22.835‰ assumed for the base case are compatible with the experimental evidence published before the paper of Kaiser (2011a; (f even if the "biological end-member" was based on a definition, there could be no argument about the "consistency" of this definition – as per its nature, a definition is arbitrary.

    The qualification of base case gross production values as being "30 % too high" must therefore also be rejected. Even though recently revised measurements of the relative 17O/16O isotope ratio difference between VSMOW and Air-O2, 17δVSMOW (Barkan and Luz, 2011, do support lower estimates of gross production, our own measurements disagree with these revised 17δVSMOW values. If scaled for differences in 18

  2. Measurements of {sup 67}Ga production cross section induced by protons on {sup nat}Zn in the low energy range from 1.678 to 2.444 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Wachter, J.A., E-mail: javier.wachter@utem.cl [Departamento de Física, Facultad de Ciencias Naturales, Matemática y del Medio Ambiente, Universidad Tecnológica Metropolitana, Santiago 7800002 (Chile); Miranda, P.A. [Departamento de Física, Facultad de Ciencias Naturales, Matemática y del Medio Ambiente, Universidad Tecnológica Metropolitana, Santiago 7800002 (Chile); Morales, J.R.; Cancino, S.A. [Departamento de Física, Facultad de Ciencias, Universidad de Chile, Casilla 653, Santiago (Chile); Correa, R. [Departamento de Física, Facultad de Ciencias Naturales, Matemática y del Medio Ambiente, Universidad Tecnológica Metropolitana, Santiago 7800002 (Chile)

    2015-02-01

    The experimental production cross section for the reaction {sup nat}Zn(p,x){sup 67}Ga has been measured in the energy range from 1.678 to 2.444 MeV. The methodology used in this work is based on characteristic X-ray emitted after irradiation by the daughter nuclei that decays by electron capture (EC) and the use of a complementary PIXE experiment. By doing so, expressions needed to determine cross section values are simplified since experimental factors such as geometric setup and an detector efficiency are avoided. {sup 67}Ga is a radionuclide particularly suited for this method since it decays by electron capture in 100% and the subsequent characteristic X-ray emission is easily detected. Natural zinc targets were fabricated by PVD technique and afterwards their thicknesses were determined by Rutherford Backscattering Spectrometry. Cross sections measurements were carried out by using the Van de Graaff accelerator located at Faculty of Sciences, University of Chile. It was found that our data for the {sup nat}Zn(p,x){sup 67}Ga reaction are, in general, in good agreement when compared to existing experimental data and to those calculated ALICE/ASH nuclear code. On the other hand, values predicted by Talys-1.6 are showing systematically lower magnitudes than our measured data.

  3. Measurements of 67Ga production cross section induced by protons on natZn in the low energy range from 1.678 to 2.444 MeV

    Science.gov (United States)

    Wachter, J. A.; Miranda, P. A.; Morales, J. R.; Cancino, S. A.; Correa, R.

    2015-02-01

    The experimental production cross section for the reaction natZn(p,x)67Ga has been measured in the energy range from 1.678 to 2.444 MeV. The methodology used in this work is based on characteristic X-ray emitted after irradiation by the daughter nuclei that decays by electron capture (EC) and the use of a complementary PIXE experiment. By doing so, expressions needed to determine cross section values are simplified since experimental factors such as geometric setup and an detector efficiency are avoided. 67Ga is a radionuclide particularly suited for this method since it decays by electron capture in 100% and the subsequent characteristic X-ray emission is easily detected. Natural zinc targets were fabricated by PVD technique and afterwards their thicknesses were determined by Rutherford Backscattering Spectrometry. Cross sections measurements were carried out by using the Van de Graaff accelerator located at Faculty of Sciences, University of Chile. It was found that our data for the natZn(p,x)67Ga reaction are, in general, in good agreement when compared to existing experimental data and to those calculated ALICE/ASH nuclear code. On the other hand, values predicted by Talys-1.6 are showing systematically lower magnitudes than our measured data.

  4. Tracking the metabolic pulse of plant lipid production with isotopic labeling and flux analyses: Past, present and future.

    Science.gov (United States)

    Allen, Doug K; Bates, Philip D; Tjellström, Henrik

    2015-04-01

    Metabolism is comprised of networks of chemical transformations, organized into integrated biochemical pathways that are the basis of cellular operation, and function to sustain life. Metabolism, and thus life, is not static. The rate of metabolites transitioning through biochemical pathways (i.e., flux) determines cellular phenotypes, and is constantly changing in response to genetic or environmental perturbations. Each change evokes a response in metabolic pathway flow, and the quantification of fluxes under varied conditions helps to elucidate major and minor routes, and regulatory aspects of metabolism. To measure fluxes requires experimental methods that assess the movements and transformations of metabolites without creating artifacts. Isotopic labeling fills this role and is a long-standing experimental approach to identify pathways and quantify their metabolic relevance in different tissues or under different conditions. The application of labeling techniques to plant science is however far from reaching it potential. In light of advances in genetics and molecular biology that provide a means to alter metabolism, and given recent improvements in instrumentation, computational tools and available isotopes, the use of isotopic labeling to probe metabolism is becoming more and more powerful. We review the principal analytical methods for isotopic labeling with a focus on seminal studies of pathways and fluxes in lipid metabolism and carbon partitioning through central metabolism. Central carbon metabolic steps are directly linked to lipid production by serving to generate the precursors for fatty acid biosynthesis and lipid assembly. Additionally some of the ideas for labeling techniques that may be most applicable for lipid metabolism in the future were originally developed to investigate other aspects of central metabolism. We conclude by describing recent advances that will play an important future role in quantifying flux and metabolic operation in plant

  5. Development of Innovative Radioactive Isotope Production Techniques at the Pennsylvania State University Radiation Science and Engineering Center

    Energy Technology Data Exchange (ETDEWEB)

    Johnsen, Amanda M. [Pennsylvania State Univ., State College, PA (United States). Radiation Science and Engineering Center; Heidrich, Brenden [Pennsylvania State Univ., State College, PA (United States). Radiation Science and Engineering Center; Durrant, Chad [Pennsylvania State Univ., State College, PA (United States). Department of mechanical and Nuclear Engineering Center; Bascom, Andrew [Pennsylvania State Univ., State College, PA (United States). Department of mechanical and Nuclear Engineering Center; Unlu, Kenan [Pennsylvania State Univ., State College, PA (United States). Radiation Science and Engineering Center

    2013-08-15

    The Penn State Breazeale Nuclear Reactor (PSBR) at the Radiation Science and Engineering Center (RSEC) has produced radioisotopes for research and commercial purposes since 1956. With the rebirth of the radiochemistry education and research program at the RSEC, the Center stands poised to produce a variety of radioisotopes for research and industrial work that is in line with the mission of the DOE Office of Science, Office of Nuclear Physics, Isotope Development and Production Research and Application Program. The RSEC received funding from the Office of Science in 2010 to improve production techniques and develop new capabilities. Under this program, we improved our existing techniques to provide four radioisotopes (Mn-56, Br-82, Na-24, and Ar-41) to researchers and industry in a safe and efficient manner. The RSEC is also working to develop new innovative techniques to provide isotopes in short supply to researchers and others in the scientific community, specifically Cu-64 and Cu-67. Improving our existing radioisotopes production techniques and investigating new and innovative methods are two of the main initiatives of the radiochemistry research program at the RSEC.

  6. Stable carbon isotope analysis ({delta}{sup 13}C values) of polybrominated diphenyl ethers and their UV-transformation products

    Energy Technology Data Exchange (ETDEWEB)

    Rosenfelder, Natalie; Bendig, Paul [University of Hohenheim, Institute of Food Chemistry (170b), Garbenstr. 28, D-70599 Stuttgart (Germany); Vetter, Walter, E-mail: walter.vetter@uni-hohenheim.de [University of Hohenheim, Institute of Food Chemistry (170b), Garbenstr. 28, D-70599 Stuttgart (Germany)

    2011-10-15

    Polybrominated diphenyl ethers (PBDEs) are frequently detected in food and environmental samples. We used compound specific isotope analysis to determine the {delta}{sup 13}C values of individual PBDEs in two technical mixtures. Within the same technical product (DE-71 or DE-79), BDE congeners were the more depleted in {sup 13}C the higher brominated they were. In contrast, the products of light-induced hydrodebromination of BDE 47 and technical DE-79 were more enriched in {sup 13}C because of more stable bonds between {sup 13}C and bromine. As a result, the {delta}{sup 13}C values of the irradiated solution progressed diametrically compared to those of the technical synthesis. The ratio of the {delta}{sup 13}C values of BDE 47 to BDE 99 and of BDE 99 to BDE 153 are thus suggested as indicators to distinguish native technical products from transformation products. Ratios <1 are typical for native congeners (e.g. in DE-71) while the reversed ratio (>1) is typical of transformation products. - Highlights: > {delta}{sup 13}C values of PBDEs were determined by means of compound specific isotope analysis. > PBDEs in technical mixtures were the more depleted in {sup 13}C the higher they were brominated. > Solutions of individual PBDEs and technical PBDE mixtures were irradiated by UV light. > {delta}{sup 13}C values of irradiated PBDEs and technical PBDEs progressed diametrically. > Ratios of the {delta}{sup 13}C values were used to distinguish native from transformed PBDEs. - Diametrically progressing {delta}{sup 13}C values in technical mixtures and UV-transformation products of DE-79 may be useful for source appointment of PBDEs in environmental samples

  7. The Effect of Molybdate Inhibition of Sulfate Reduction on the Production and Stable Isotopic Composition of Methane in Hypersaline Environments

    Science.gov (United States)

    Kelley, C. A.; Bebout, B.; Chanton, J.; Beaudoin, C. S.; Detweiler, A. M.; Frisbee, A.; Nicholson, B. E.; Poole, J.; Tazaz, A.

    2016-12-01

    Methane and its stable isotope value have been suggested as biosignatures in the search for life on other planets, such as Mars. On Earth, both today and over geologic time, the amount of methane produced and its δ13C value can be affected by the competition between methanogens and sulfate reducing bacteria. We investigated the effect of this competition by determining methane (CH4) production rates and δ13CH4 values with and without added molybdate, a specific inhibitor of sulfate reduction. Samples of photosynthetic soft microbial mats and gypsum-encrusted endoevaporites were obtained from Mars analog sites in hypersaline environments from California, Mexico and Chile. Methane production was determined from the increase in headspace CH4 concentration within incubation vials. At the end of the incubation period, a sample of the headspace was analyzed for its δ13CH4 value. At the lower salinity soft microbial mat sites, the vials that contained molybdate tended to have dramatically higher CH4 production rates and higher δ13CH4 values than the controls. This suggests that when sulfate reduction is inhibited, the methanogens at these sites were able to use the competitive substrate, H2, thus accounting for the greatly increased CH4 production rate. Further, the higher δ13CH4 values suggest that substrates (both competitive and non-competitive) were used to near completion. At the higher salinity endoevaporite sites, CH4 production tended to either increase slightly or not at all with added molybdate, and the δ13CH4 values tended to either stay the same or decrease to some degree. We suggest that if production was only marginally increased or not at all with added molybdate, the increase in substrate availability may have allowed for somewhat greater isotopic fractionation and the lower δ13CH4 values that were observed. Where no changes in either rates or δ13CH4 values occurred, we hypothesize that salinity itself was controlling microbe population and

  8. Production of Rare Earth Isotope Beams for Radiotracer-DLTS on SiC

    CERN Multimedia

    2002-01-01

    Electrical properties of semiconductors are extremely sensitive to minor traces of impurities and defects. This fact allows to intentionally modify material properties and is thus the very basis of semiconductor electronics and optoelectronics. In the present project, electronic properties and doping effects of rare-earth elements in the technologically important semiconductor SiC are to be investigated using optical and electrical characterization techniques like Photoluminescence, Deep Level Transient Spectroscopy and Thermal Admittance Spectroscopy. By using the elemental transmutation of radioactive isotopes as a tracer, it will be guaranteed that the impurity-related band gap states can definitively be distinguished from intrinsic or process-induced defects. For SiC up to now only detailed investigation of Er- related deep levels have been reported, preliminary data exist for Sm- and Gd- impurities. In this project we propose the implantation of Pr and Eu isotopes for detailed level studies.

  9. Degradation of sulfamethoxazole using ozone and chlorine dioxide - Compound-specific stable isotope analysis, transformation product analysis and mechanistic aspects.

    Science.gov (United States)

    Willach, Sarah; Lutze, Holger V; Eckey, Kevin; Löppenberg, Katja; Lüling, Michelle; Terhalle, Jens; Wolbert, Jens-Benjamin; Jochmann, Maik A; Karst, Uwe; Schmidt, Torsten C

    2017-10-01

    The sulfonamide antibiotic sulfamethoxazole (SMX) is a widely detected micropollutant in surface and groundwaters. Oxidative treatment with e.g. ozone or chlorine dioxide is regularly applied for disinfection purposes at the same time exhibiting a high potential for removal of micropollutants. Especially for nitrogen containing compounds such as SMX, the related reaction mechanisms are largely unknown. In this study, we systematically investigated reaction stoichiometry, product formation and reaction mechanisms in reactions of SMX with ozone and chlorine dioxide. To this end, the neutral and anionic SMX species, which may occur at typical pH-values of water treatment were studied. Two moles of chlorine dioxide and approximately three moles of ozone were consumed per mole SMX degraded. Oxidation of SMX with ozone and chlorine dioxide leads in both cases to six major transformation products (TPs) as revealed by high-resolution mass spectrometry (HRMS). Tentatively formulated TP structures from other studies could partly be confirmed by compound-specific stable isotope analysis (CSIA). However, for one TP, a hydroxylated SMX, it was not possible by HRMS alone to identify whether hydroxylation occurred at the aromatic ring, as suggested in literature before, or at the anilinic nitrogen. By means of CSIA and an analytical standard it was possible to identify sulfamethoxazole hydroxylamine unequivocally as one of the TPs of the reaction of SMX with ozone as well as with chlorine dioxide. H-abstraction and electron transfer at the anilinic nitrogen are suggested as likely initial reactions of ozone and chlorine dioxide, respectively, leading to its formation. Oxidation of anionic SMX with ozone did not show any significant isotopic fractionation whereas the other reactions studied resulted in a significant carbon isotope fractionation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Biogeochemical controls and isotopic signatures of nitrous oxide production by a marine ammonia-oxidizing bacterium

    Directory of Open Access Journals (Sweden)

    C. H. Frame

    2010-09-01

    medium also increased N2O yields by an average of 70% to 87% depending on O2 concentration. We made stable isotopic measurements on N2O from these cultures to identify the biochemical mechanisms behind variations in N2O yield. Based on measurements of δ15Nbulk, site preference (SP = δ15Nα−δ15Nβ, and δ18O of N2O (δ18O-N2O, we estimate that nitrifier-denitrification produced between 11% and 26% of N2O from cultures grown under 20% O2 and 43% to 87% under 0.5% O2. We also demonstrate that a positive correlation between SP and δ18O-N2O is expected when nitrifying bacteria produce N2O. A positive relationship between SP and δ18O-N2O has been observed in environmental N2O datasets, but until now, explanations for the observation invoked only denitrification. Such interpretations may overestimate the role of heterotrophic denitrification and underestimate the role of ammonia oxidation in environmental N2O production.

  11. Generation of Radixenon Isotopes

    Energy Technology Data Exchange (ETDEWEB)

    McIntyre, Justin I.; Bowyer, Ted W.; Hayes, James C.; Heimbigner, Tom R.; Morris, Scott J.; Panisko, Mark E.; Pitts, W. K.; Pratt, Sharon L.; Reeder, Paul L.; Thomas, Charles W.

    2003-06-30

    Pacific Northwest National Laboratory has developed an automated system for separating Xe from air and can detect the following radioxenon isotopes, 131mXe, 133mXe, 133Xe, and 135Xe. This report details the techniques used to generate the various radioxenon isotopes that are used for the calibration of the detector as well as other isotopes that have the potential to interfere with the fission produced radioxenon isotopes. Fission production is covered first using highly enriched uranium followed by a description and results from an experiment to produce radioxenon isotopes from neutron activation of ambient xenon.

  12. Measuring the Cosmic Ray Muon-Induced Fast Neutron Spectrum by (n,p) Isotope Production Reactions in Underground Detectors

    CERN Document Server

    Galbiati, C; Galbiati, Cristiano; Beacom, John. F.

    2005-01-01

    While cosmic ray muons themselves are relatively easy to veto in underground detectors, their interactions with nuclei create more insidious backgrounds via: (i) the decays of long-lived isotopes produced by muon-induced spallation reactions inside the detector, (ii) spallation reactions initiated by fast muon-induced neutrons entering from outside the detector, and (iii) nuclear recoils initiated by fast muon-induced neutrons entering from outside the detector. These backgrounds, which are difficult to veto or shield against, are very important for solar, reactor, dark matter, and other underground experiments, especially as increased sensitivity is pursued. We used fluka to calculate the production rates and spectra of all prominent secondaries produced by cosmic ray muons, in particular focusing on secondary neutrons, due to their importance. Since the neutron spectrum is steeply falling, the total neutron production rate is sensitive just to the relatively soft neutrons, and not to the fast-neutron compon...

  13. The high-spin {sup 178m2}Hf isomer: production, chemical and isotopic separations, gamma spectrometry and internal conversion electrons spectrometry; L`isomere de haut spin {sup 178m2}Hf: production, separations chimiques et isotopiques, spectrometrie gamma et spectrometrie d`electrons de conversion interne

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.B.

    1993-10-13

    The high-spin isometric state of the nucleus 178Hf is a challenge for new and exotic nuclear physics studies. With its long half-life of 31 years, the production of a reasonable micro-weight quantity, with an isometric to ground state ratio as high as 5 per cent, is now regularly performed by intensive irradiations of ytterbium targets with helium ions of 36 MeV. Using sur-enriched, at 99,998 per cent, ytterbium 176 that we have prepared at the PARIS mass separator, the isomer purity has been improved. Targets of such material but also of enriched stable isotopes of hafnium have been prepared by electro-spraying of methanolic and acetic solutions. By inelastic diffusion of protons and deuton on these targets, the energy of the first state of the rotation band built on the isomer has been measured. Isotopic separations of the isomer have been performed, with a yield greater than 20 per cent, by the use of isotopically pure hafnium 176 as carrier. The separated beam of the mass 178 allowed to record the complete hyperfine spectrum of the isomer and to measure, for the first time, the magnetic dipole moment and the electric quadrupole moment. Isomer targets, implanted in various materials like copper, iron and hafnium monocrystal, provide the opportunity to accurately measure gamma and internal conversion decay of this nuclei and so to precise the multipolarity mixing of all transitions from K=16{sup +} to K=8{sup -}. (author). 49 refs., 47 figs., 11 tabs.

  14. Accelerator based Production of Auger-Electron-emitting Isotopes for Radionuclide Therapy

    DEFF Research Database (Denmark)

    Thisgaard, Helge

    Sb from the enriched 119Sn target material with high radionuclidic- and chemical purity. A method that also allows efficient recovery of the 119Sn for recycling. To demonstrate the ability of producing therapeutic quantities of 119Sb and other radioisotopes for therapy with a low-energy cyclotron...... isotopes (e.g. 119Sb or 64Cu) using the PETtrace cyclotron commonly found at the larger PET-centers in the hospitals. Finally, research in a new method to measure the radiotoxicity of Auger-emitters invitro using cellular microinjection has been carried out. The purpose of this method is to be able...

  15. Production of Nuclear Polarization of Na Isotopes at ISAC/TRIUMF and its Hyperfine Interaction

    Energy Technology Data Exchange (ETDEWEB)

    Minamisono, K., E-mail: minamiso@nscl.msu.edu [NSCL/MSU (United States); Matsuta, K.; Minamisono, T. [Osaka University, Department of Physics (Japan); Levy, C. D. P. [TRIUMF (Canada); Nagatomo, T.; Ogura, M. [Osaka University, Department of Physics (Japan); Sumikama, T. [RIKEN (Japan); Behr, J. A.; Jackson, K. P. [TRIUMF (Canada); Fujiwara, H.; Mihara, M.; Fukuda, M. [Osaka University, Department of Physics (Japan)

    2004-12-15

    Hyperfine interactions of Na isotopes in single crystals have been studied using highly nuclear polarized {sup 20,21,26,27,28}Na beams provided by ISAC/TRIUMF. The degree of polarization kept in the crystals, the spin-lattice relaxation times, the electric quadrupole coupling constants and the initial distribution of the populations were measured. Such knowledge is indispensable for the application of the hyperfine interactions in the study of precision measurements such as the nuclear structure through nuclear moments and the fundamental symmetries.

  16. Hydrogen Isotope Measurements of Organic Acids and Alcohols by Pyrolysis-GC-MS-TC-IRMS: Application to Analysis of Experimentally Derived Hydrothermal Mineral-Catalyzed Organic Products

    Science.gov (United States)

    Socki, Richard A.; Fu, Qi; Niles, Paul B.; Gibson, Everett K., Jr.

    2012-01-01

    We report results of experiments to measure the H isotope composition of organic acids and alcohols. These experiments make use of a pyroprobe interfaced with a GC and high temperature extraction furnace to make quantitative H isotope measurements. This work compliments our previous work that focused on the extraction and analysis of C isotopes from the same compounds [1]. Together with our carbon isotope analyses our experiments serve as a "proof of concept" for making C and H isotope measurements on more complex mixtures of organic compounds on mineral surfaces in abiotic hydrocarbon formation processes at elevated temperatures and pressures. Our motivation for undertaking this work stems from observations of methane detected within the Martian atmosphere [2-5], coupled with evidence showing extensive water-rock interaction during Mars history [6-8]. Methane production on Mars could be the result of synthesis by mineral surface-catalyzed reduction of CO2 and/or CO by Fischer-Tropsch Type (FTT) reactions during serpentization [9,10]. Others have conducted experimental studies to show that FTT reactions are plausible mechanisms for low-molecular weight hydrocarbon formation in hydrothermal systems at mid-ocean ridges [11-13]. Our H isotope measurements utilize an analytical technique combining Pyrolysis-Gas Chromatograph-Mass Spectrometry-High Temperature Conversion-Isotope Ratio Mass Spectrometry (Py-GC-MS-TC-IRMS). This technique is designed to carry a split of the pyrolyzed GC-separated product to a Thermo DSQII quadrupole mass spectrometer as a means of making qualitative and semi-quantitative compositional measurements of separated organic compounds, therefore both chemical and isotopic measurements can be carried out simultaneously on the same sample.

  17. Partitioning CO2 production with stable carbon isotopes in a peatland ecosystem

    Science.gov (United States)

    Corbett, J.; Chanton, J.; tfaily, M. M.; Cooper, W. T.; Burdige, D. J.; Glaser, P. H.

    2011-12-01

    We developed an isotope mass-balance model to predict the percent of CO2 formed from either organic-matter fermentation or methanogenesis using pore water δ13C-CO2 and δ13C-CH4 in a peatland ecosystem. Our second objective was to determine percent CH4 loss using CO2 and CH4 concentrations and the predicted percent of CO2 from methanogenesis. The assumption that methanogenesis produces equimolar amounts of CH4 and CO2 and multiple field and incubation measurements that show higher concentrations of CO2 indicate that organic-matter fermentation is an important respiration pathway in these systems. Lower concentrations of CH4 could be accounted for by ebullition and vascular-plant transport. A closed system incubation study was done to determine if predicted CO2 and CH4 concentrations calculated using isotopes compared to measured concentration values. The average difference between the two approaches was 3.5%. Using the model to analyze field measurements, we found that a higher percent of CO2 was produced from methanogenesis than organic matter fermentation in both bog and fen environments. At depths, bogs had a slightly higher percent of CO2 from methanogenesis (100%) than did fens (90%). Surface depths shallower than 50cm produced a significantly larger (20%) amount of CO2 from organic-matter fermentation than deeper depths. Bogs and fens showed a similar amount of methane loss between 85-100% depending on depth.

  18. (238)U/(235)U isotope ratios of crustal material, rivers and products of hydrothermal alteration: new insights on the oceanic U isotope mass balance.

    Science.gov (United States)

    Noordmann, Janine; Weyer, Stefan; Georg, R Bastian; Jöns, Svenja; Sharma, Mukul

    2016-01-01

    In this study, the U isotope composition, n((238)U)/n((235)U), of major components of the upper continental crust, including granitic rocks of different age and post-Archaean shales, as well as that of rivers (the major U source to the oceans) was investigated. Furthermore, U isotope fractionation during the removal of U at mid-ocean ridges, an important sink for U from the oceans, was investigated by the analyses of hydrothermal water samples (including low- and high-temperature fluids), low-temperature altered basalts and calcium carbonate veins. All analysed rock samples from the continental crust fall into a limited range of δ(238)U between -0.45 and -0.21 ‰ (relative to NBL CRM 112-A), with an average of -0.30 ± 0.15 ‰ (2 SD, N = 11). Despite differences in catchment lithologies, all major rivers define a relatively narrow range between -0.31 and -0.13 ‰, with a weighted mean isotope composition of -0.27 ‰, which is indistinguishable from the estimate for the upper continental crust (-0.30 ‰). Only some tributary rivers from the Swiss Alps display a slightly larger range in δ(238)U (-0.29 to +0.01 ‰) and lower U concentrations (0.87-3.08 nmol/kg) compared to the investigated major rivers (5.19-11.69 nmol/kg). These findings indicate that only minor net U isotope fractionation occurs during weathering and transport of material from the continental crust to the oceans. Altered basalts display moderately enriched U concentrations (by a factor of 3-18) compared to those typically observed for normal mid-ocean ridge basalts. These, and carbonate veins within altered basalts, show large U isotope fractionation towards both heavy and light U isotope compositions (ranging from -0.63 to +0.27 ‰). Hydrothermal water samples display low U concentrations (0.3-1 nmol/kg) and only limited variations in their U isotope composition (-0.43 ± 0.25 ‰) around the seawater value. Nevertheless, two of the investigated fluids display

  19. A consistent set of neutron kerma coefficients from thermal to 150 MeV for biologically important materials

    Energy Technology Data Exchange (ETDEWEB)

    Chadwick, M.B. [University of California, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Barschall, H.H. [Department of Medical Physics, University of Wisconsin, Madison, Wisconsin 53706-1532 (United States); Caswell, R.S. [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); DeLuca, P.M. [Department of Medical Physics, University of Wisconsin, Madison, Wisconsin 53706-1532 (United States); Hale, G.M. [University of California, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Jones, D.T. [National Accelerator Centre, Faure, CapeTown (South Africa); MacFarlane, R.E. [University of California, Los Alamos, National Laboratory, Los Alamos, New Mexico 87545 (United States); Meulders, J.P. [Universite Catholique de Louvain, Louvain-la-Neuve (Belgium); Schuhmacher, H.; Schrewe, U.J. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany); Wambersie, A. [Universite Catholique de Louvain, Louvain-la-Neuve (Belgium); Young, P.G. [University of California, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    1999-06-01

    Neutron cross sections for nonelastic and elastic reactions on a range of elements have been evaluated for incident energies up to 150 MeV. These cross sections agree well with experimental cross section data for charged-particle production as well as neutron and photon production. Therefore they can be used to determine kerma coefficients for calculations of energy deposition by neutrons in matter. Methods used to evaluate the neutron cross sections above 20 MeV, using nuclear model calculations and experimental data, are described. Below 20 MeV, the evaluated cross sections from the ENDF/B-VI library are adopted. Comparisons are shown between the evaluated charged-particle production cross sections and measured data. Kerma coefficients are derived from the neutron cross sections, for major isotopes of H, C, N, O, Al, Si, P, Ca, Fe, Cu, W, Pb, and for ICRU-muscle, A-150 tissue-equivalent plastic, and other compounds important for treatment planning and dosimetry. Numerous comparisons are made between our kerma coefficients and experimental kerma coefficient data, to validate our results, and agreement is found to be good. An important quantity in neutron dosimetry is the kerma coefficient ratio of ICRU-muscle to A-150 plastic. When this ratio is calculated from our kerma coefficient data, and averaged over the neutron energy spectra for higher-energy clinical therapy beams [three p(68)+Be beams, and a d(48.5)+Be beam], a value of 0.94{plus_minus}0.03 is obtained. Kerma ratios for water to A-150 plastic, and carbon to oxygen, are also compared with measurements where available. {copyright} {ital 1999 American Association of Physicists in Medicine.}

  20. Eleven new heaviest isotopes of elements Z = 105 to Z = 117 identified among the products of 249Bk+48Ca reactions

    Energy Technology Data Exchange (ETDEWEB)

    Oganessian, Yuri Ts. [FLNR-JINR, Russia; Abdullin, F. Sh. [Joint Institute for Nuclear Research, Dubna, Russia; Bailey, P. D. [Oak Ridge National Laboratory (ORNL); Benker, D. E. [Oak Ridge National Laboratory (ORNL); Bennett, M. E. [University of Nevada, Las Vegas; Dmitriev, S. [FLNR-JINR, Russia; Ezold, Julie G. [Oak Ridge National Laboratory (ORNL); Hamilton, J. H. [Vanderbilt University; Henderson, R. [Lawrence Livermore National Laboratory (LLNL); Itkis, M. G. [FLNR-JINR, Russia; Lobanov, Yu. V. [Joint Institute for Nuclear Research, Dubna, Russia; Mezentsev, A. N. [Joint Institute for Nuclear Research, Dubna, Russia; Moody, K. [Lawrence Livermore National Laboratory (LLNL); Nelson, S. L. [Lawrence Livermore National Laboratory (LLNL); Polyakov, A. N. [Joint Institute for Nuclear Research, Dubna, Russia; Porter, C. E. [Oak Ridge National Laboratory (ORNL); Ramayya, A. V. [Vanderbilt University; Riley, F. D. [Oak Ridge National Laboratory (ORNL); Roberto, James B [ORNL; Ryabinin, M. A. [Research Institute of Atomic Reactors, Dimitrovgrad, Russia; Rykaczewski, Krzysztof Piotr [ORNL; Taylor, R [Oak Ridge National Laboratory (ORNL); Tsyganov, Yu. S. [Joint Institute for Nuclear Research, Dubna, Russia; Utyonkov, V. [FLNR-JINR, Russia; Voinov, A. A. [Joint Institute for Nuclear Research, Dubna, Russia; Vostokin, G. K. [Joint Institute for Nuclear Research, Dubna, Russia; Wilk, P. A. [Lawrence Livermore National Laboratory (LLNL)

    2011-01-01

    The heaviest isotopes of elements Z = 117 to Z = 105, 294117, 293117, 290115, 289115, 286113, 285113, 282Rg, 281Rg, 278Mt, 274Bh, and 270Db, were identified by means of the Dubna gas-filled recoil separator among the products of the 249Bk + 48Ca reaction. The details of the observed six decay chains, indicating the production and decay of isotopes 293117 and 294117, are presented and discussed. The decay energies and resulting half-lives of these new nuclei show a strong rise of stability with increasing neutron number, validating the concept of the island of enhanced stability for superheavy nuclei.

  1. Determining the isotopic compositions of uranium and fission products in radioactive environmental microsamples using laser ablation ICP-MS with multiple ion counters.

    Science.gov (United States)

    Boulyga, Sergei F; Prohaska, Thomas

    2008-01-01

    This paper presents the application of a multicollector inductively coupled plasma mass spectrometer (MC-ICP-MS)--a Nu Plasma HR--equipped with three ion-counting multipliers and coupled to a laser ablation system (LA) for the rapid and sensitive determination of the 235U/238U, 236U/238U, 145Nd/143Nd, 146Nd/143Nd, 101Ru/(99Ru+99Tc) and 102Ru/(99Ru+99Tc) isotope ratios in microsamples collected in the vicinity of Chernobyl. Microsamples with dimensions ranging from a hundred mum to about 1 mm and with surface alpha activities of 3-38 mBq were first identified using nuclear track radiography. U, Nd and Ru isotope systems were then measured sequentially for the same microsample by LA-MC-ICP-MS. The application of a zoom ion optic for aligning the ion beams into the ion counters allows fast switching between different isotope systems, which enables all of the abovementioned isotope ratios to be measured for the same microsample within a total analysis time of 15-20 min (excluding MC-ICP-MS optimization and calibration). The 101Ru/(99Ru+99Tc) and 102Ru/(99Ru+99Tc) isotope ratios were measured for four microsamples and were found to be significantly lower than the natural ratios, indicating that the microsamples were contaminated with the corresponding fission products (Ru and Tc). A slight depletion in 146Nd of about 3-5% was observed in the contaminated samples, but the Nd isotopic ratios measured in the contaminated samples coincided with natural isotopic composition within the measurement uncertainty, as most of the Nd in the analyzed samples originates from the natural soil load of this element. The 235U/238U and 236U/238U isotope ratios were the most sensitive indicators of irradiated uranium. The present work yielded a significant variation in uranium isotope ratios in microsamples, in contrast with previously published results from the bulk analysis of contaminated samples originating from the vicinity of Chernobyl. Thus, the 235U/238U ratios measured in ten

  2. Collective motion in selected central collisions of Au on Au at 150A MeV

    Science.gov (United States)

    Jeong, S. C.; Herrmann, N.; Fan, Z. G.; Freifelder, R.; Gobbi, A.; Hildenbrand, K. D.; Krämer, M.; Randrup, J.; Reisdorf, W.; Schüll, D.; Sodan, U.; Teh, K.; Wessels, J. P.; Pelte, D.; Trzaska, M.; Wienold, T.; Alard, J. P.; Amouroux, V.; Basrak, Z.; Bastid, N.; Belayev, I. M.; Berger, L.; Bini, M.; Blaich, Th.; Boussange, S.; Buta, A.; Čaplar, R.; Cerruti, C.; Cindro, N.; Coffin, J. P.; Dona, R.; Dupieux, P.; Erö, J.; Fintz, P.; Fodor, Z.; Fraysse, L.; Frolov, S.; Grigorian, Y.; Guillaume, G.; Hölbling, S.; Houari, A.; Jundt, F.; Kecskemeti, J.; Koncz, P.; Korchagin, Y.; Kotte, R.; Kuhn, C.; Ibnouzahir, M.; Legrand, I.; Lebedev, A.; Maguire, C.; Manko, V.; Maurenzig, P.; Mgebrishvili, G.; Mösner, J.; Moisa, D.; Montarou, G.; Montbel, I.; Morel, P.; Neubert, W.; Olmi, A.; Pasquali, G.; Petrovici, M.; Poggi, G.; Rami, F.; Ramillien, V.; Sadchikov, A.; Seres, Z.; Sikora, B.; Simion, V.; Smolyankin, S.; Tezkratt, R.; Vasiliev, M. A.; Wagner, P.; Wilhelmi, Z.; Wohlfarth, D.; Zhilin, A. V.

    1994-05-01

    Using the FOPI facility at GSI Darmstadt complete data of Au on Au collisions at 150A MeV were collected for charged products (Z=1-15) at laboratory angles 1°=3) are used to determine the collective energy which is found to be at least 10A MeV.

  3. Pyrogenic carbon from tropical savanna burning: production and stable isotope composition

    Directory of Open Access Journals (Sweden)

    G. Saiz

    2014-10-01

    C4 grasses ranging from 35 to 99% of total biomass. Residues from each fire were partitioned into PyC and further into recalcitrant (HyPyC components, with each of these also partitioned into proximal (> 125 μm and distal (13C compositions of PyC and HyPyC were generally lower by 1–3‰ relative to the original biomass, with marked depletion up to 7 ‰ for grasslands dominated by C4 biomass. δ13C values of CO2 produced by combustion was computed by mass balance and ranged from ~0.4 to 1.3‰. The depletion of 13C in PyC and HyPyC relative to the original biomass has significant implications for the interpretation of δ13C values of savanna soil organic carbon and of ancient PyC preserved in the geologic record, and for global 13C isotopic disequilibria calculations.

  4. CO2 production by impact in carbonates? An ATEM and stable isotope (C,O) study

    Science.gov (United States)

    Martinez, I.; Agrinier, P.; Guyot, F.; Ildefonse, PH.; Javoy, M.; Schaerer, U.; Hornemann, U.; Deutsch, A.

    1993-01-01

    Carbonates may have been a common target for large impacts on the Earth and possible related CO2 outgassing would have important consequences for the composition of the atmosphere. To estimate volatile release during such impacts, isotopic ratios (C-13/C-12 and O-18/O-16) were determined on highly shocked carbonate samples in combination with SEM and analytical transmission electron microscopy (ATEM) investigations. The study was performed on both naturally and experimentally shocked rocks, i.e. 50-60 GPa shocked limestone-dolomite fragments from the Haughton impact crater (Canada), and carbonates shocked in shock recovery experiments. For the experiments, unshocked carbonates consisting of mixture of dolomite and calcite from the Haughton area were used. Naturally shocked samples were collected in the polymict breccia near the center of the Haughton crater.

  5. Study of activation cross-sections of deuteron induced reactions on rhodium up to 40 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Ditroi, F., E-mail: ditroi@atomki.hu [Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), Debrecen (Hungary); Tarkanyi, F.; Takacs, S. [Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), Debrecen (Hungary); Hermanne, A. [Cyclotron Laboratory, Vrije Universiteit Brussel (VUB), Brussels (Belgium); Yamazaki, H.; Baba, M.; Mohammadi, A. [Cyclotron Radioisotope Center (CYRIC) Tohoku University, Sendai (Japan); Ignatyuk, A.V. [Institute of Physics and Power Engineering (IPPE), Obninsk (Russian Federation)

    2011-09-15

    Highlights: {yields} Excitation function measurement of deuteron induced reactions on rhodium up to 40 MeV. {yields} Model code calculations with EMPIRE, ALICE and TALYS. {yields} Integral production yield calculation. {yields} Thin layer activation (TLA) with the produced isotopes. - Abstract: In the frame of a systematic study of the activation cross-sections of deuteron induced nuclear reactions, excitation functions of the {sup 103}Rh(d,x) {sup 100,101,103}Pd, {sup 100g,101m,101g,102m,102g}Rh and {sup 103g}Ru reactions were determined up to 40 MeV. Cross-sections were measured with the activation method using a stacked foil irradiation technique. Excitation functions of the contributing reactions were calculated using the ALICE-IPPE, EMPIRE-II and TALYS codes. From the measured cross-section data integral production yields were calculated and compared with experimental integral yield data reported in the literature. From the measured cross-sections and previous data, activation curves were deduced to support thin layer activation (TLA) on rhodium and Rh containing alloys.

  6. Activation cross-sections of deuteron induced nuclear reactions on rhenium up to 40 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Ditrói, F., E-mail: ditroi@atomki.hu [Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), Debrecen (Hungary); Tárkányi, F.; Takács, S. [Institute of Nuclear Research of the Hungarian Academy of Sciences (ATOMKI), Debrecen (Hungary); Hermanne, A. [Cyclotron Laboratory, Vrije Universiteit Brussel (VUB), Brussels (Belgium); Yamazaki, H.; Baba, M.; Mohammadi, A. [Cyclotron Radioisotope Center (CYRIC), Tohoku University, Sendai (Japan); Ignatyuk, A.V. [Institute of Physics and Power Engineering (IPPE), Obninsk (Russian Federation)

    2013-02-01

    Highlights: ► Excitation function measurement of deuteron induced reactions on rhenium up to 40 MeV. ► Model code calculations with EMPIRE-D, ALICE-D and TALYS (TENDL-2011). ► Integral production yield calculation. ► Thin layer activation (TLA) curves; {sup 185}Os and {sup 186}Re. -- Abstract: As a part of a thorough work of excitation functions on deuteron induced reactions, experimental cross-sections of {sup 185,183m,183g,182}Os and {sup 188,186,184m,184g,183}Re activation products on {sup nat}Re were measured up to 40 MeV for the first time with the activation method using a stacked foil irradiation technique and high resolution γ-spectrometry. Comparison with the former results of other laboratories and with the predictions of the ALICE-IPPE and EMPIRE-3 model codes, modified for improved calculations for deuteron reactions, and with data in the TENDL-2011 library are also presented. Thick target yields were given deduced from our experimental cross-sections and compared with the few literature values. For practical applications (thin layer activation) also activity versus depth distributions were calculated for selected isotopes.

  7. Neutron inelastic scattering measurements on the stable isotopes of titanium

    Science.gov (United States)

    Olacel, A.; Belloni, F.; Borcea, C.; Boromiza, M.; Dessagne, P.; Henning, G.; Kerveno, M.; Negret, A.; Nyman, M.; Pirovano, E.; Plompen, A. J. M.

    2017-07-01

    The results of a neutron inelastic scattering experiment performed at the Geel Electron Linear Accelerator pulsed white neutron source of the European Commission Joint Research Centre are reported. The neutrons with energies up to 18 MeV interacted with a natTi sample and the γ rays resulting from inelastic scattering reactions on the stable isotopes were detected using the Gamma Array for Inelastic Neutron Scattering (GAINS) spectrometer. We were able to measure the γ -production cross sections for 21 transitions in the five stable Ti isotopes. From these, the level cross sections and the total inelastic cross sections were determined. Our experimental results are compared with theoretical calculations performed using the talys 1.8 code, evaluated nuclear data libraries, and also with previously reported results.

  8. Comment on: "Technical note: Consistent calculation of aquatic gross production from oxygen triple isotope measurements" by Kaiser (2011

    Directory of Open Access Journals (Sweden)

    D. P. Nicholson

    2011-10-01

    Full Text Available Kaiser (2011 has introduced an improved method for calculating gross productivity from the triple isotopic composition of dissolved oxygen in aquatic systems. His equation avoids approximations of previous methodologies, and also accounts for additional physical processes such as kinetic fractionation during invasion and evasion at the air-sea interface. However, when comparing his new approach to previous methods, Kaiser inconsistently defines the biological end-member with the result of overestimating the degree to which the various approaches of previous studies diverge. In particular, for his base case, Kaiser assigns a 17O excess to the product of photosynthesis (17δP that is too low, resulting in his result being ~30 % too high when compared to previous equations. When this is corrected, I find that Kaiser's equations are consistent with all previous study methodologies within about ±20 % for realistic conditions of metabolic balance (f and gross productivity (g. A methodological bias of ±20 % is of similar magnitude to current uncertainty in the wind-speed dependence of the air-sea gas transfer velocity, k, which directly impacts calculated gross productivity rates as well. While previous results could and should be revisited and corrected using the proposed improved equations, the magnitude of such corrections may be much less than implied by Kaiser.

  9. Isotopic and sedimentological clues to productivity change in Late Riphean Sea: A case study from two intracratonic basins of India

    Indian Academy of Sciences (India)

    P P Chakraborty; A Sarkar; S K Bhattacharya; P Sanyal

    2002-12-01

    Enriched 13C/12 ratios with 13C ∼3‰ (w.r.t PDB) of two Late Riphean (∼700-610Ma) intracratonic carbonate successions viz., Bhander Limestone of Vindhyan Basin and Raipur Limestone of Chattisgarh Basin suggest higher organic productivity during this period. This view is supported by sedimentological evidence of higher biohermal growth and consequent increase in depositional relief in the low gradient ramp settings inferred for these basins. Oxygen isotope analysis of these carbonates show distinct segregation between enriched deeper water carbonate mudstone and depleted shallow water stromatolite facies that received fresh water influx. This shows that facies-specific analyses can be useful in understanding the depositional setting of these sediments.

  10. Production of stable isotope labelled lipase Lip2 from Yarrowia lipolytica for NMR: investigation of several expression systems.

    Science.gov (United States)

    Nars, G; Saurel, O; Bordes, F; Saves, I; Remaud-Siméon, M; André, I; Milon, A; Marty, A

    2014-09-01

    Extracellular lipase Lip2 from Yarrowia lipolytica is a promising biocatalyst with unusual structural features, as indicated by X-ray crystallography. These features comprise a mobile domain called the lid that controls access to the catalytic site. Conformational rearrangements of the lid have been suggested to regulate lipase enzymatic activities. We used nuclear magnetic resonance to investigate the dynamics of Lip2 by exploring four expression systems, Escherichia coli, cell-free, Pichia pastoris and Y. lipolytica to produce uniformly labelled enzyme. The expression of Lip2 was assessed by determining its specific activity and measuring (15)N-(1)H HSQC spectra. Y. lipolytica turned out to be the most efficient expression system. Here, we report the first use of Y. lipolytica as an expression host for the production of uniform stable isotopic labelled protein for further structural and dynamics studies using NMR.

  11. Excitation functions of alpha particle induced reactions on {sup nat}Ti up to 40 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Uddin, M.S., E-mail: md.shuzauddin@yahoo.com [Tandem Accelerator Facilities, Institute of Nuclear Science and Technology, Atomic Energy Research Establishment, Savar, Dhaka (Bangladesh); Scholten, B. [Institut für Neurowissenschaften und Medizin, INM-5:Nuklearchemie, Forschungszentrum Jülich, D-52425 Jülich (Germany)

    2016-08-01

    Excitation functions of the reactions {sup nat}Ti(α,x){sup 48}Cr, {sup nat}Ti(α,x){sup 48}V and {sup nat}Ti(α,x){sup 46,48}Sc were determined by the stacked-foil activation technique up to 40 MeV. The radioactivities produced in the {sup nat}Ti target were measured by γ-ray spectrometry using HPGe detector. The reaction {sup nat}Ti(α,x){sup 51}Cr was used to determine the beam parameters. New experimental values for the above reactions have been obtained. An intercomparison of our data with the available literature values has been done. The cross section results obtained in this work could be useful in defining new monitor reactions, radiation safety and isotope production.

  12. Excitation functions of alpha particle induced reactions on natTi up to 40 MeV

    Science.gov (United States)

    Uddin, M. S.; Scholten, B.

    2016-08-01

    Excitation functions of the reactions natTi(α,x)48Cr, natTi(α,x)48V and natTi(α,x)46,48Sc were determined by the stacked-foil activation technique up to 40 MeV. The radioactivities produced in the natTi target were measured by γ-ray spectrometry using HPGe detector. The reaction natTi(α,x)51Cr was used to determine the beam parameters. New experimental values for the above reactions have been obtained. An intercomparison of our data with the available literature values has been done. The cross section results obtained in this work could be useful in defining new monitor reactions, radiation safety and isotope production.

  13. Assessing the hydraulic connection between fresh water aquifers and unconventional gas production using methane and stable isotopes

    Science.gov (United States)

    Iverach, Charlotte P.; Cendón, Dioni I.; Hankin, Stuart I.; Lowry, Dave; Fisher, Rebecca E.; France, James L.; Nisbet, Euan G.; Baker, Andy; Kelly, Bryce F. J.

    2015-04-01

    Unconventional gas developments pose a risk to groundwater quality and quantity in adjacent or overlying aquifers. To manage these risks there is a need to measure the background concentration of indicator groundwater chemicals and to map pathways of hydraulic connectivity between aquifers. This study presents methane (CH4) concentration and isotopic composition, dissolved organic carbon concentration ([DOC]) and tritium (3H) activity data from an area of expanding coal seam gas (CSG) exploration and production (Condamine Catchment, south-east Queensland, Australia). The target formation for gas production within the Condamine Catchment is the Walloon Coal Measures (WCM). This is a 700 m thick, low-rank CSG resource, which consists of numerous thin discontinuous lenses of coal separated by very fine-to medium-grained sandstone, siltstone, and mudstone, with minor calcareous sandstone, impure limestone and ironstone. The thickness of the coal makes up less than 10% of the total thickness of the unit. The WCM are overlain by sandstone formations, which form part of the Great Artesian Basin (GAB). The Condamine Alluvium fills a paleo-valley carved through the above formations. A combination of groundwater and degassing air samples were collected from irrigation bores and government groundwater monitoring boreholes. Degassing air samples were collected using an SKC 222-2301 air pump, which pumped the gas into 3 L Tedlar bags. The groundwater was analysed for 3H and [DOC]. A mobile CH4 survey was undertaken to continuously sample air in and around areas of agricultural and unconventional gas production. The isotopic signature of gas from the WCM was determined by sampling gas that was off-gassing from a co-produced water holding pond as it was the largest emission that could be directly linked to the WCM. This was used to determine the source signature of the CH4 from the WCM. We used Keeling plots to identify the source signature of the gas sampled. For the borehole

  14. Denitrification and anammox in tropical aquaculture settlement ponds: an isotope tracer approach for evaluating N2 production.

    Directory of Open Access Journals (Sweden)

    Sarah A Castine

    Full Text Available Settlement ponds are used to treat aquaculture discharge water by removing nutrients through physical (settling and biological (microbial transformation processes. Nutrient removal through settling has been quantified, however, the occurrence of, and potential for microbial nitrogen (N removal is largely unknown in these systems. Therefore, isotope tracer techniques were used to measure potential rates of denitrification and anaerobic ammonium oxidation (anammox in the sediment of settlement ponds in tropical aquaculture systems. Dinitrogen gas (N(2 was produced in all ponds, although potential rates were low (0-7.07 nmol N cm(-3 h(-1 relative to other aquatic systems. Denitrification was the main driver of N(2 production, with anammox only detected in two of the four ponds. No correlations were detected between the measured sediment variables (total organic carbon, total nitrogen, iron, manganese, sulphur and phosphorous and denitrification or anammox. Furthermore, denitrification was not carbon limited as the addition of particulate organic matter (paired t-Test; P = 0.350, n = 3 or methanol (paired t-Test; P = 0.744, n = 3 did not stimulate production of N(2. A simple mass balance model showed that only 2.5% of added fixed N was removed in the studied settlement ponds through the denitrification and anammox processes. It is recommended that settlement ponds be used in conjunction with additional technologies (i.e. constructed wetlands or biological reactors to enhance N(2 production and N removal from aquaculture wastewater.

  15. Denitrification and anammox in tropical aquaculture settlement ponds: an isotope tracer approach for evaluating N2 production.

    Science.gov (United States)

    Castine, Sarah A; Erler, Dirk V; Trott, Lindsay A; Paul, Nicholas A; de Nys, Rocky; Eyre, Bradley D

    2012-01-01

    Settlement ponds are used to treat aquaculture discharge water by removing nutrients through physical (settling) and biological (microbial transformation) processes. Nutrient removal through settling has been quantified, however, the occurrence of, and potential for microbial nitrogen (N) removal is largely unknown in these systems. Therefore, isotope tracer techniques were used to measure potential rates of denitrification and anaerobic ammonium oxidation (anammox) in the sediment of settlement ponds in tropical aquaculture systems. Dinitrogen gas (N(2)) was produced in all ponds, although potential rates were low (0-7.07 nmol N cm(-3) h(-1)) relative to other aquatic systems. Denitrification was the main driver of N(2) production, with anammox only detected in two of the four ponds. No correlations were detected between the measured sediment variables (total organic carbon, total nitrogen, iron, manganese, sulphur and phosphorous) and denitrification or anammox. Furthermore, denitrification was not carbon limited as the addition of particulate organic matter (paired t-Test; P = 0.350, n = 3) or methanol (paired t-Test; P = 0.744, n = 3) did not stimulate production of N(2). A simple mass balance model showed that only 2.5% of added fixed N was removed in the studied settlement ponds through the denitrification and anammox processes. It is recommended that settlement ponds be used in conjunction with additional technologies (i.e. constructed wetlands or biological reactors) to enhance N(2) production and N removal from aquaculture wastewater.

  16. Estimation of pathways of the production of greenhouse gases in the tropical swamp forest in Thailand by stable isotope investigation.

    Science.gov (United States)

    Boontanon, Narin; Ueda, Shingo; Wada, Eitaro

    2008-09-01

    Dynamics of greenhouse gases (N(2)O and CH(4)) with the dry-wet cycle along with the variation of oxidation-reduction boundaries were investigated in the tropical wetland in monsoon Asia. It was clarified that the production of N(2)O and CH(4) was closely related to the development of a redox boundary in the Bang Nara River systems. An intermittent increase in N(2)O was observed at the beginning of the rainy season, when a large amount of easily decomposable organic matter was introduced into the river. After 10 days, when dissolved oxygen was consumed completely at the middle reaches, the emission of CH(4) became maximal due to the possible occurrence of denitrification. The distribution of stable isotope ratios in N(2)O clearly demonstrated that nitrification is the major process for its production. Furthermore, the production of N(2)O in this study area was found to vary in time and space with changes in the redox boundary along the water flow.

  17. Rapid determination of parabens in personal care products by stable isotope GC-MS/MS with dynamic selected reaction monitoring.

    Science.gov (United States)

    Wang, Perry G; Zhou, Wanlong

    2013-06-01

    In this study, a rapid and sensitive analytical method for the determination of methyl-, ethyl-, propyl-, and butyl esters of para-hydroxy benzoic acid (parabens) in personal care products was developed and fully validated. Test portions were extracted with methanol followed by vortexing, sonication, centrifugation, and filtration without derivatization. The four parabens were quantified by GC-MS/MS in the electron ionization mode. Four corresponding isotopically labeled parabens were selected as internal standards, which were added at the beginning of the sample preparation and used to correct for recovery and matrix effects. Sensitivity, extraction efficiency, and recovery of the respective analytes were evaluated. The coefficients of determination (r(2)) were all greater than 0.995 for the four parabens investigated. The recoveries ranged from 97 to 107% at three spiked levels and a one-time (single) extraction efficiency greater than 97% was obtained. This method has been applied to screen 26 personal care products. This is the first time that a unique GC-MS/MS method with dynamic selected reaction monitoring and confirmation of analytes has been used to determine these parabens in cosmetic personal care products.

  18. Recognition of n-alkyl and isoprenoid biopolymers in marine sediments by stable carbon isotopic analysis of pyrolysis products of kerogens

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Hold, I.M.; Schouten, S.; Kaam-Peters, H.M.E. van

    1998-01-01

    Analysis of the pyrolysis products of several marine kerogens revealed that the stable carbon isotopic composition of the n-alkanes (C10-C25) are quite similar to those of the n-alkenes. This suggests that they have a common origin such as algal biopolymers. The isoprenoid alkanes (C13-C20) also hav

  19. Improvement on Fermionic properties and new isotope production in molecular dynamics simulations

    CERN Document Server

    Wang, Ning; Zeng, Jie; Yang, Yongxu; Ou, Li

    2016-01-01

    By considering momentum transfer in the Fermi constraint procedure, the stability of the initial nuclei and fragments produced in heavy-ion collisions can be further improved in the quantum molecular dynamics simulations. The case of the phase space occupation probability larger than one is effectively reduced with the proposed procedure. Simultaneously, the energy conservation can be better described for both individual nuclei and heavy-ion reactions. With the revised version of the improved quantum molecular dynamics (ImQMD) model, the fusion excitation functions of $^{16}$O+$^{186}$W and the central collisions of Au+Au at 35 AMeV are re-examined. The fusion cross sections at sub-barrier energies and the charge distribution of fragments are relatively better reproduced due to the reduction of spurious nucleon emission. The charge and isotope distribution of fragments in Xe+Sn, U+U and Zr+Sn at intermediate energies are also predicted. More unmeasured extremely neutron-rich fragments with $Z=16-28$ are obser...

  20. A dual nitrite isotopic investigation of chemodenitrification by mineral-associated Fe(II) and its production of nitrous oxide

    Science.gov (United States)

    Grabb, Kalina C.; Buchwald, Carolyn; Hansel, Colleen M.; Wankel, Scott D.

    2017-01-01

    Under anaerobic conditions, the environmental reduction of nitrate (NO3-) and nitrite (NO2-) to more reduced forms is widely regarded as being microbially catalyzed. However, the chemical reduction of oxidized nitrogen species by reduced iron (Fe(II)), whether mineral-bound or surface-associated, may also occur under environmentally relevant conditions. Here we examine the nitrogen (N) and oxygen (O) stable isotope dynamics of the chemical reduction of NO2- by mineral associated Fe(II) (chemodenitrification) and its production of the potent greenhouse gas nitrous oxide (N2O). By shedding light on factors controlling kinetics of the reaction and its corresponding dual isotopic expression in the reactant NO2- and product N2O, this work contributes to a growing body of work aiming to improve our ability to identify chemodenitrification in the environment. Consistent with previous studies, we find that while homogenous reactions between aqueous NO2- and Fe(II) were kinetically slow, heterogeneous reactions involving Fe(II)-containing minerals often catalyzed considerable nitrite loss. In particular, rapid reduction of NO2- was catalyzed by the Fe-rich smectite clay mineral nontronite as well as the mixed Fe(II)-Fe(III) oxyhydroxide phase green rust. These minerals serve as both a source of reduced iron within the mineral structure as well as a surface for promoting the reactivity of Fe(II). However, even in the presence of aqueous Fe(II), experiments with low-Fe and non-Fe containing minerals showed little to no NO2- loss, perhaps suggesting a more dominant role for structural iron during chemodenitrification. When catalyzed by nontronite and green rust, N and O isotope effects for chemodenitrification (15εcDNF and 18εcDNF) ranged from 2 to 11‰ and 4 to 10‰, respectively, with lower values generally observed at higher reaction rates. Higher reaction rates were also linked to higher molar yields of N2O (up to 31%), highlighting a strong potential for

  1. Catalytic recombination of dissociation products with Pt/SnO2 for rare and common isotope long-life, closed-cycle CO2 lasers

    Science.gov (United States)

    Brown, Kenneth G.; Sidney, B. D.; Schryer, D. R.; Upchurch, B. T.; Miller, I. M.

    1986-01-01

    This paper reports results on recombination of pulsed CO2 laser dissociation products with Pt/SnO2 catalysts, and supporting studies in a surrogate laboratory catalyst reactor. The closed-cycle, pulsed CO2 laser has been continuously operated for one million pulses with an overall power degradation of less than 5 percent by flowing the laser gas mixture through a 2-percent Pt/SnO2 catalyst bed. In the surrogate laboratory reactor, experiments have been conducted to determine isotopic exchange with the catalyst when using rare-isotope gases. The effects of catalyst pretreatment, sample weight, composition, and temperature on catalyst efficiency have also been determined.

  2. Isotopic distributions of the sup 1 sup 8 N fragmentation products in coincidence with neutrons on targets sup 1 sup 9 sup 7 Au and sup 9 Be

    CERN Document Server

    Li Xiang Qing; Ye Yan Lin; Hua Hui; Chen Tao; Li Zhi Huan; Ge Yuch Eng; Wang Quan Jin; Wu He Yu; Jin Ge; Duan Li Min; Xiao Zhi Gang; Wang Hong Wei; Li Zhu Yu; Wang Su Fang

    2002-01-01

    The authors present the experimental isotopic distributions of the sup 1 sup 8 N projectile fragmentation products Li, Be, B and C in coincidence with neutrons, as well as the inclusive ones on sup 1 sup 9 sup 7 Au and sup 9 Be targets. In the framework of the abrasion-ablation model, these distributions are calculated for various nucleon density distributions of the projectile. The comparison with experimental isotopic distributions of the projectile-like fragments in coincidence with neutrons shows that the information on the nucleon density distribution of the sup 1 sup 8 N projectile can be extracted

  3. Variation of the isotopic composition of complexing reaction products as a result of isotopically selective excitation of the molecules of one of the reagents

    Energy Technology Data Exchange (ETDEWEB)

    Kapralova, G.A.; Makharinskii, L.E.; Trofimova, E.M.; Chaikin, A.M.

    1980-05-05

    The possibility of influencing the complexing reaction rate by laser radiation was examined. The variation of the isotopic composition of BCl/sub 3/ in the reaction BCl/sub 3/+N(CH/sub 3/)/sub 3/=BCl/sub 3/N(CH/sub 3/)/sub 3/ was shown experimentally as a result of selective excitation of /sup 11/BCl/sub 3/ by CO/sub 2/ laser radiation.

  4. Mock-up Test for Isotope Target Transport and Cooling System

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Sang-pil; Kwon, Hyeok-jung; Kim, Han-sung; Cho, Yong-sub; Chung, Bo-hyun; Seol, Kyung-tae; Song, Young-gi; Kim, Dae-il; Min, Yi-sub [KOMAC, Gyeongju (Korea, Republic of)

    2015-10-15

    In this paper, we described the design and fabrication of the test mock-up of target transport and cooling system for the isotope production by using the 100-MeV proton irradiation. For Sr-82 production, RbCl target and aluminum dummy target was prepared. These targets are contained in the target carrier, which could transported by drive chain and guide rail system. Korea multi-purpose Accelerator Complex (KOMAC) has a plan to construct the new proton beam irradiation facility for the production of radioisotopes. Sr-82 and Cu-67 were selected as the target isotope in this facility, they are promising isotope for the PET imaging and cancer therapy. To produce Sr-82 by 100- MeV proton irradiation, RbCl were chosen as a target material due to their high melting point and easy separation. For the facility construction, we have designed targetry system which consists of target, target transport system and target cooling system. This paper describes the details of targetry system.

  5. The formation of weathering products on the LEW 85320 ordinary chondrite - Evidence from carbon and oxygen stable isotope compositions and implications for carbonates in SNC meteorites

    Science.gov (United States)

    Grady, Monica M.; Wright, I. P.; Pillinger, C. T.; Gibson, E. K., Jr.

    1989-01-01

    Isotopic analysis of nesquehonite recovered from the surface of the LEW 85320 H5 ordinary chondrite shows that the delta C-13 and delta O-18 values of the two generations of bicarbonate (Antarctic and Texas) are different: delta C-13 = + 7.9 per mil and + 4.2 per mil; delta O-18 = + 17.9 per mil and + 12.1 per mil, respectively. Carbon isotopic compositions are consistent with equilibrium formation from atmospheric carbon dioxide at - 2 + or - 4 C (Antarctic) and + 16 + or - 4 C (Texas). Oxygen isotopic data imply that the water required for nesquehonite precipitation was derived from atmospheric water vapor or glacial meltwater which had locally exchanged with silicates, either in the meteorite or in underlying bedrock. Although carbonates with similar delta C-13 values have been identified in the SNC meteorites EETA 79001 and Nakhla, petrographic and temperature constraints argue against their simply being terrestrial weathering products.

  6. Stable isotope labelling reveals that NaCl stress decreases the production of Ensifer (Sinorhizobium) arboris lipochitooligosaccharide signalling molecules.

    Science.gov (United States)

    Penttinen, Petri; Räsänen, Leena A; Lortet, Gilles; Lindström, Kristina

    2013-12-01

    Ensifer (Sinorhizobium) arboris is a symbiont of salt-tolerant leguminous trees in the genera Acacia and Prosopis that are utilized in the prevention of soil erosion and desertification and in phytoremediation of salinized soil. Signalling between the plant and the rhizobia is essential for the formation of effective symbiosis that increases the success of reclaiming saline sites. We assessed the effect of salt stress on the growth and the production of lipochitooligosaccharide signalling molecules (LCOs) of S. arboris HAMBI 2361, an LCO-overproducing derivative of the S. arboris type strain HAMBI 1552. The strain tolerated NaCl up to 750 mM. To obtain both qualitative and quantitative information on the LCO production under salt stress, we devised a method where LCOs were differentially labelled by stable isotopes of nitrogen, (14)N and (15)N, and analysed by mass spectrometry. Under control conditions, the strain produced altogether 27 structural LCO variants. In 380 mM NaCl, 13 LCO variants were produced in detectable amounts, and six of these were reliably quantified, ranging from one-tenth to one-third of the non-stressed one.

  7. Evaluation of Primary Production in the Lower Amazon River Based on a Dissolved Oxygen Stable Isotopic Mass Balance

    Energy Technology Data Exchange (ETDEWEB)

    Gagne-Maynard, William C.; Ward, Nicholas D.; Keil, Richard G.; Sawakuchi, Henrique O.; Da Cunha, Alan C.; Neu, Vania; Brito, Daimio C.; Da Silva Less, Diani F.; Diniz, Joel E. M.; De Matos Valerio, Aline; Kampel, Milton; Krusche, Alex V.; Richey, Jeffrey E.

    2017-02-07

    The Amazon River outgasses nearly an equivalent amount of CO2 as the rainforest sequesters on an annual basis due to microbial decomposition of terrigenous and aquatic organic matter. Most research performed in the Amazon has been focused on unraveling the mechanisms driving CO2 production since the recognition of a persistent state of CO2 supersaturation. However, although the river system is clearly net heterotrophic, the interplay between primary production and respiration is an essential aspect to understanding the overall metabolism of the ecosystem and potential transfer of energy up trophic levels. For example, an efficient ecosystem is capable of both decomposing high amounts of organic matter at lower trophic levels, driving CO2 emissions, and accumulating energy/biomass in higher trophic levels, stimulating fisheries production. Early studies found minimal evidence for primary production in the Amazon River mainstem and it has since been assumed that photosynthesis is strongly limited by low light penetration attributed to the high sediment load. Here, we test this assumption by measuring the stable isotopic composition of O218O-O2) and O2 saturation levels in the lower Amazon River from Óbidos to the river mouth and its major tributaries, the Xingu and Tapajós rivers, during high and low water periods. An oxygen mass balance model was developed to estimate the input of photosynthetic oxygen in the discrete reach from Óbidos to Almeirim, midway to the river mouth. Based on the oxygen mass balance we estimate that primary production occurred at a rate of 0.39 ± 0.24 g O m3 d-1 at high water and 1.02 ± 0.55 g O m3 d-1 at low water. This translates to 41 ± 24% of the rate of O2 drawdown via respiration during high water and 67 ± 33% during low water. These primary production rates are 2-7 times higher than

  8. Alignments in the nobelium isotopes

    Institute of Scientific and Technical Information of China (English)

    ZHENG Shi-Zie; XU Fu-Rong; YUAN Cen-Xi; QI Chong

    2009-01-01

    Total-Routhian-Surface calculations have been performed to investigate the deformation and align-ment properties of the No isotopes. It is found that normal deformed and superdeformed states in these nuclei can coexist at low excitation energies. In neutron-deficient No isotopes, the superdeformed shapes can even become the ground states. Moreover, we plotted the kinematic moments of inertia of the No isotopes, which follow very nicely available experimental data. It is noted that, as the rotational frequency increases, align-ments develop at hω=0.2-0.3 MeV. Our calculations show that the occupation of the vj orbital plays an important role in the alignments of the No isotopes.

  9. Shielding calculations for industrial 5/7.5MeV electron accelerators using the MCNP Monte Carlo Code

    Science.gov (United States)

    Peri, Eyal; Orion, Itzhak

    2017-09-01

    High energy X-rays from accelerators are used to irradiate food ingredients to prevent growth and development of unwanted biological organisms in food, and by that extend the shelf life of the products. The production of X-rays is done by accelerating 5 MeV electrons and bombarding them into a heavy target (high Z). Since 2004, the FDA has approved using 7.5 MeV energy, providing higher production rates with lower treatments costs. In this study we calculated all the essential data needed for a straightforward concrete shielding design of typical food accelerator rooms. The following evaluation is done using the MCNP Monte Carlo code system: (1) Angular dependence (0-180°) of photon dose rate for 5 MeV and 7.5 MeV electron beams bombarding iron, aluminum, gold, tantalum, and tungsten targets. (2) Angular dependence (0-180°) spectral distribution simulations of bremsstrahlung for gold, tantalum, and tungsten bombarded by 5 MeV and 7.5 MeV electron beams. (3) Concrete attenuation calculations in several photon emission angles for the 5 MeV and 7.5 MeV electron beams bombarding a tantalum target. Based on the simulation, we calculated the expected increase in dose rate for facilities intending to increase the energy from 5 MeV to 7.5 MeV, and the concrete width needed to be added in order to keep the existing dose rate unchanged.

  10. International challenge to predict the impact of radioxenon releases from medical isotope production on a comprehensive nuclear test ban treaty sampling station.

    Science.gov (United States)

    Eslinger, Paul W; Bowyer, Ted W; Achim, Pascal; Chai, Tianfeng; Deconninck, Benoit; Freeman, Katie; Generoso, Sylvia; Hayes, Philip; Heidmann, Verena; Hoffman, Ian; Kijima, Yuichi; Krysta, Monika; Malo, Alain; Maurer, Christian; Ngan, Fantine; Robins, Peter; Ross, J Ole; Saunier, Olivier; Schlosser, Clemens; Schöppner, Michael; Schrom, Brian T; Seibert, Petra; Stein, Ariel F; Ungar, Kurt; Yi, Jing

    2016-06-01

    The International Monitoring System (IMS) is part of the verification regime for the Comprehensive Nuclear-Test-Ban-Treaty Organization (CTBTO). At entry-into-force, half of the 80 radionuclide stations will be able to measure concentrations of several radioactive xenon isotopes produced in nuclear explosions, and then the full network may be populated with xenon monitoring afterward. An understanding of natural and man-made radionuclide backgrounds can be used in accordance with the provisions of the treaty (such as event screening criteria in Annex 2 to the Protocol of the Treaty) for the effective implementation of the verification regime. Fission-based production of (99)Mo for medical purposes also generates nuisance radioxenon isotopes that are usually vented to the atmosphere. One of the ways to account for the effect emissions from medical isotope production has on radionuclide samples from the IMS is to use stack monitoring data, if they are available, and atmospheric transport modeling. Recently, individuals from seven nations participated in a challenge exercise that used atmospheric transport modeling to predict the time-history of (133)Xe concentration measurements at the IMS radionuclide station in Germany using stack monitoring data from a medical isotope production facility in Belgium. Participants received only stack monitoring data and used the atmospheric transport model and meteorological data of their choice. Some of the models predicted the highest measured concentrations quite well. A model comparison rank and ensemble analysis suggests that combining multiple models may provide more accurate predicted concentrations than any single model. None of the submissions based only on the stack monitoring data predicted the small measured concentrations very well. Modeling of sources by other nuclear facilities with smaller releases than medical isotope production facilities may be important in understanding how to discriminate those releases from

  11. Quantification of DNA damage products resulting from deamination, oxidation and reaction with products of lipid peroxidation by liquid chromatography isotope dilution tandem mass spectrometry

    Science.gov (United States)

    Taghizadeh, Koli; McFaline, Jose L.; Pang, Bo; Sullivan, Matthew; Dong, Min; Plummer, Elaine; Dedon, Peter C.

    2009-01-01

    The analysis of damage products as biomarkers of inflammation has been hampered by a poor understanding of the chemical biology of inflammation, the lack of sensitive analytical methods, and a focus on single chemicals as surrogates for inflammation. To overcome these problems, we developed a general and sensitive liquid chromatographic tandem mass spectrometry (LC/MS-MS) method to quantify, in a single DNA sample, the nucleoside forms of seven DNA lesions reflecting the range of chemistries associated with inflammation: 2′-deoxyuridine, 2′-deoxyxanthosine, and 2′-deoxyinosine from nitrosative deamination; 8-oxo-2′-deoxyguanosine from oxidation; and 1,N2-etheno-2′-deoxyguanosine, 1,N6-etheno-2′-deoxyadenosine, and 3,N4-etheno-2′-deoxycytidine arising from reaction of DNA with lipid peroxidation products. Using DNA purified from cells or tissues under conditions that minimize artifacts, individual nucleosides are purified by HPLC and quantified by isotope-dilution, electrospray ionization LC/MS-MS. The method can be applied to other DNA damage products and requires 4-6 days to complete depending upon the number of samples. PMID:18714297

  12. Nitrogen isotopic evidence for a shift from nitrate- to diazotroph-fueled export production in VAHINE mesocosm experiments

    Directory of Open Access Journals (Sweden)

    A. N. Knapp

    2015-12-01

    Full Text Available In a shallow, coastal lagoon off the southwest coast of New Caledonia, large-volume (~ 50 m3 mesocosm experiments were undertaken to track the fate of newly fixed nitrogen (N. The mesocosms were intentionally fertilized with 0.8 μM dissolved inorganic phosphorus (DIP to stimulate diazotrophy. N isotopic evidence indicates that the dominant source of N fueling export production shifted from subsurface nitrate (NO3− assimilated prior to the start of the 23 day experiments to N2 fixation by the end of the experiments. While the δ15N of the sinking particulate N (PNsink flux changed during the experiments, the δ15N of the suspended PN (PNsusp and dissolved organic N (DON pools did not. This is consistent with previous observations that the δ15N of surface ocean N pools is less responsive than that of PNsink to changes in the dominant source of new N to surface waters. In spite of the absence of detectable NO3− in the mesocosms, the δ15N of PNsink indicated that NO3− continued to fuel a significant fraction of export production (20 to 60 % throughout the 23 day experiments, with N2 fixation dominating export after about two weeks. The low rates of primary productivity and export production during the first 14 days were primarily supported by NO3−, and phytoplankton abundance data suggest that export was driven by large diatoms sinking out of surface waters. Concurrent molecular and taxonomic studies indicate that the diazotroph community was dominated by diatom-diazotroph assemblages (DDAs at this time. However, these DDAs represented a minor fraction (2 fixation; they were thus not important for driving export production, either directly or indirectly. The unicellular cyanobacterial diazotroph, a Cyanothece-like UCYN-C, proliferated during the last phase of the experiments when N2 fixation, primary production, and the flux of PNsink increased significantly, and δ15N budgets reflected a predominantly diazotrophic source of N fueling

  13. Synthesis of the isotopes of elements 118 and 116 in the 249Cf and 245Cm+48Ca fusion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Oganessian, Y T; Utyonkov, V K; Lobanov, Y V; Abdullin, F S; Polyakov, A N; Sagaidak, R N; Shirokovsky, I V; Tsyganov, Y S; Voinov, A A; Gulbekian, G G; Bogomolov, S L; Gikal, B N; Mezentsev, A N; Iliev, S; Subbotin, V G; Sukhov, A M; Subotic, K; Zagrebaev, V I; Vostokin, G K; Itkis, M G; Moody, K J; . Patin, J B; Shaughnessy, D A; Stoyer, M A; Stoyer, N J; Wilk, P A; Kenneally, J M; Landrum, J H; Wild, J F; Lougheed, R W

    2006-01-31

    The decay properties of {sup 290}116 and {sup 291}116, and the dependence of their production cross sections on the excitation energies of the compound nucleus, {sup 293}116, have been measured in the {sup 245}Cm({sup 48}Ca,xn){sup 293-x}116 reaction. These isotopes of element 116 are the decay daughters of element 118 isotopes, which are produced via the {sup 249}Cf+{sup 48}Ca reaction. They performed the element 118 experiment at two projectile energies, corresponding to {sup 297}118 compound nucleus excitation energies of E* = 29.2 {+-} 2.5 and 34.4 {+-} 2.3 MeV. During an irradiation with a total beam dose of 4.1 x 10{sup 19} {sup 48}Ca projectiles, three similar decay chains consisting of two or three consecutive {alpha} decays and terminated by a spontaneous fission (SF) with high total kinetic energy of about 230 MeV were observed. The three decay chains originated from the even-even isotope {sup 294}118 (E{sub {alpha}} = 11.65 {+-} 0.06 MeV, T{sub {alpha}} = 0.89{sub -0.31}{sup +1.07} ms) produced in the 3n-evaporation channel of the {sup 249}Cf+{sup 48}Ca reaction with a maximum cross section of 0.5{sub -0.3}{sup +1.6} pb.

  14. Reply to Nicholson's comment on "Consistent calculation of aquatic gross production from oxygen triple isotope measurements" by Kaiser (2011

    Directory of Open Access Journals (Sweden)

    J. Kaiser

    2012-08-01

    Full Text Available The comment by Nicholson (2011a questions the "consistency" of the "definition" of the "biological end-member" used by Kaiser (2011a in the calculation of oxygen gross production. "Biological end-member" refers to the relative oxygen isotope ratio difference between photosynthetic oxygen and Air-O2 (abbreviated 17δP and 18δP for 17O/16O and 18O/16O, respectively. The comment claims that this leads to an overestimate of the discrepancy between previous studies and that the resulting gross production rates are "30% too high". Nicholson recognises the improved accuracy of Kaiser's direct calculation ("dual-delta" method compared to previous approximate approaches based on 17O excess (17Δ and its simplicity compared to previous iterative calculation methods. Although he correctly points out that differences in the normalised gross production rate (g are largely due to different input parameters used in Kaiser's "base case" and previous studies, he does not acknowledge Kaiser's observation that iterative and dual-delta calculation methods give exactly the same g for the same input parameters (disregarding kinetic isotope fractionation during air-sea exchange. The comment is based on misunderstandings with respect to the "base case" 17δP and 18δP values. Since direct measurements of 17δP and 18δPdo not exist or have been lost, Kaiser constructed the "base case" in a way that was consistent and compatible with literature data. Nicholson showed that an alternative reconstruction of 17δP gives g values closer to previous studies. However, unlike Nicholson, we refrain from interpreting either reconstruction as a benchmark for the accuracy of g. A number of publications over the last 12 months

  15. Microbial Oxidation of Hg(0) - Its Effect on Hg Stable Isotope Fractionation and Methylmercury Production

    Energy Technology Data Exchange (ETDEWEB)

    Yee, Nathan [Rutgers Univ., New Brunswick, NJ (United States); Barkay, Tamar [Rutgers Univ., New Brunswick, NJ (United States); Reinfelder, John [Rutgers Univ., New Brunswick, NJ (United States)

    2016-06-28

    relationship between Hg concentrations and rates of denitrification in enrichment cultures. In part III of our project, we examined in more detail the effects of microbial interactions on Hg transformations. We discovered that both sulfate reducing and iron reducing bacteria coexist in freshwater sediments and both microbial groups contribute to mercury methylation. We showed that mercury methylation by sulfate reducing and iron reducing bacteria are temporally and spatially separated processes. We also discovered that methanogens can methylate mercury. We showed that Methanospirillum hungatei JF-1 methylated Hg at comparable rates, but with higher yields, than those observed for sulfate-reducing bacteria and iron-reducing bacteria. Finally, we demonstrated that syntrophic interactions between different microbial groups increase mercury methylation rates. We showed that Hg methylation rates are stimulated via inter-species hydrogen and acetate transfer (i) from sulfate-reducing bacteria to methanogens and (ii) from fermenters to the sulfate-reducing bacteria. In part IV of the project, we studied Hg bioavailability and Hg isotope fractionation. We demonstrated that thiol-bound Hg is bioavailable to mercury resistant bacteria. We found that uptake of Hg from Hg-glutathione and Hg-cysteine complexes does not require functioning glutathione and cystine/cysteine transport systems. We demonstrated that a wide range of methylmercury complexes (e.g. MeHgOH, MeHg-cysteine, and MeHg-glutathione) are bioavailable to mercury resistant bacteria. The rate of MeHg demethylation varies more between different species of mercury resistant bacteria than among MeHg complexes. We showed that microbial demethylation of MeHg depends more on the species of microorganism than on the types and relative concentrations of thiols or other MeHg ligands present. Finally, we demonstrated that Hg methylation by Geobacter sulfurreducens PCA and Desulfovibrio desulfuricans ND132 imparts mass

  16. Microbial Oxidation of Hg(0) - Its Effect on Hg Stable Isotope Fractionation and Methylmercury Production

    Energy Technology Data Exchange (ETDEWEB)

    Yee, Nathan [Rutgers Univ., New Brunswick, NJ (United States); Barkay, Tamar [Rutgers Univ., New Brunswick, NJ (United States); Reinfelder, John [Rutgers Univ., New Brunswick, NJ (United States)

    2016-06-28

    relationship between Hg concentrations and rates of denitrification in enrichment cultures. In part III of our project, we examined in more detail the effects of microbial interactions on Hg transformations. We discovered that both sulfate reducing and iron reducing bacteria coexist in freshwater sediments and both microbial groups contribute to mercury methylation. We showed that mercury methylation by sulfate reducing and iron reducing bacteria are temporally and spatially separated processes. We also discovered that methanogens can methylate mercury. We showed that Methanospirillum hungatei JF-1 methylated Hg at comparable rates, but with higher yields, than those observed for sulfate-reducing bacteria and iron-reducing bacteria. Finally, we demonstrated that syntrophic interactions between different microbial groups increase mercury methylation rates. We showed that Hg methylation rates are stimulated via inter-species hydrogen and acetate transfer (i) from sulfate-reducing bacteria to methanogens and (ii) from fermenters to the sulfate-reducing bacteria. In part IV of the project, we studied Hg bioavailability and Hg isotope fractionation. We demonstrated that thiol-bound Hg is bioavailable to mercury resistant bacteria. We found that uptake of Hg from Hg-glutathione and Hg-cysteine complexes does not require functioning glutathione and cystine/cysteine transport systems. We demonstrated that a wide range of methylmercury complexes (e.g. MeHgOH, MeHg-cysteine, and MeHg-glutathione) are bioavailable to mercury resistant bacteria. The rate of MeHg demethylation varies more between different species of mercury resistant bacteria than among MeHg complexes. We showed that microbial demethylation of MeHg depends more on the species of microorganism than on the types and relative concentrations of thiols or other MeHg ligands present. Finally, we demonstrated that Hg methylation by Geobacter sulfurreducens PCA and Desulfovibrio desulfuricans ND132 imparts mass

  17. Production of neutron-rich isotopes in {sup 82}Se+{sup 238}U grazing reaction

    Energy Technology Data Exchange (ETDEWEB)

    Marginean, N.; Corradi, L. [INFN, Laboratori Nazionali di Legnaro Padova (Italy); Berghini, S. [National Institute for Physics and Nuclear Engineering, Bucharest (Romania)] (and others)

    2005-07-01

    The reactions at the grazing angle between heavy ions at energies close to the Coulomb barrier are presently considered as a valuable tool for the production of nuclei far from stability, particularly in the neutron-rich area. Recent high mass-resolution experiments demonstrated that one could observe the transfer of up to six proton stripping (-6p) and six neutron pick-up (+6n) channels with cross sections down to {approx}50-100 {mu}b.

  18. Automated product recovery in a Hg-196 photochemical isotope separation process

    Science.gov (United States)

    Grossman, M.W.; Speer, R.

    1992-07-21

    A method of removing deposited product from a photochemical reactor used in the enrichment of [sup 196]Hg has been developed and shown to be effective for rapid re-cycling of the reactor system. Unlike previous methods relatively low temperatures are used in a gas and vapor phase process of removal. Importantly, the recovery process is understood in a quantitative manner so that scaling design to larger capacity systems can be easily carried out. 2 figs.

  19. Analysis of polonium-210 in food products and bioassay samples by isotope-dilution alpha spectrometry.

    Science.gov (United States)

    Lin, Zhichao; Wu, Zhongyu

    2009-05-01

    A rapid and reliable radiochemical method coupled with a simple and compact plating apparatus was developed, validated, and applied for the analysis of (210)Po in variety of food products and bioassay samples. The method performance characteristics, including accuracy, precision, robustness, and specificity, were evaluated along with a detailed measurement uncertainty analysis. With high Po recovery, improved energy resolution, and effective removal of interfering elements by chromatographic extraction, the overall method accuracy was determined to be better than 5% with measurement precision of 10%, at 95% confidence level.

  20. Isotopic Evidence For The Primary Production, Provenance And Trade Of Late Bronze Age Glass In The Mediterranean.

    Science.gov (United States)

    Henderson, J.; Evans, J.; Nikita, K.

    The earliest known man made glass comes from Mesopotamia and dates to the 23rd century BC. By the 16th century BC the first glass vessels appear in Mesopotamia, but the earliest evidence for the fusion of glass from raw materials has been found at the 13th century BC Egyptian site of Qantir. Chemical analyses of this elite Late Bronze Age material have produced compositional distinctions between glasses found in Mesopotamia and Egypt. It is however debatable whether trace element concentrations provide a (geological) provenance for the glasses. By using neodymium and strontium isotopes to fingerprint well-dated chemically analysed 15th to 11th century BC glass samples, we show that independent primary production probably occurred in both Egypt and Mesopotamia in the 14th century BC, and that both of these areas exported glass to Greece. We also discuss the technological implications for glass manufacture and colouring that these new data provide. The results add significant new scientific evidence for glass trade between Late Bronze Age palatial societies. Moreover, it is the first time that this methodology has been used to investigate Bronze Age glass.

  1. Deuterium isotope effects on toluene metabolism. Product release as a rate-limiting step in cytochrome P-450 catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Ling, K.H.; Hanzlik, R.P.

    1989-04-28

    Liver microsomes from phenobarbital-induced rats oxidize toluene to a mixture of benzyl alcohol plus o-, m- and p-cresol (ca. 69:31). Stepwise deuteration of the methyl group causes stepwise decreases in the yield of benzyl alcohol relative to cresols (ca. 24:76 for toluene-d3). For benzyl alcohol formation from toluene-d3 DV = 1.92 and D(V/K) = 3.53. Surprisingly, however, stepwise deuteration induces stepwise increases in total oxidation, giving rise to an inverse isotope effect overall (DV = 0.67 for toluene-d3). Throughout the series (i.e. d0, d1, d2, d3) the ratios of cresol isomers remain constant. These results are interpreted in terms of product release for benzyl alcohol being slower than release of cresols (or their epoxide precursors), and slow enough to be partially rate-limiting in turnover. Thus metabolic switching to cresol formation causes a net acceleration of turnover.

  2. Activation cross sections of proton and deuteron induced nuclear reactions on holmium and erbium, related to the production of $^{161}$Er and $^{160}$Er medical isotopes

    CERN Document Server

    Tárkányi, F; Takács, S; Hermanne, A; Baba, M

    2016-01-01

    Experimental excitation functions for long-lived products in proton induced reactions were measured with the activation method in the 37-65 MeV energy range on natural holmium. Stacked foil irradiation technique and high resolution gamma spectrometry were used in order to measure cross-section data for the production of $^{161}$Er, $^{160}$Er and $^{159,157}$Dy. For comparison of the production routes of medically related $^{161}$Er and $^{160}$Er radioisotopes new experimental cross section data were deduced for the $^{162}$Er(p,x)$^{161,160}$Er and $^{162}$Er(d,x)$^{161,160}$Er reactions by re-evaluating gamma-ray spectra from earlier measurements. No earlier data were found in the literature for these reactions. The experimental data are compared with results of TALYS theoretical code reported in TENDL-2015.

  3. Activation cross sections of proton and deuteron induced nuclear reactions on holmium and erbium, related to the production of (161)Er and (160)Er medical isotopes.

    Science.gov (United States)

    Tárkányi, F; Ditrói, F; Takács, S; Hermanne, A; Baba, M

    2016-09-01

    Experimental excitation functions for long-lived products in proton induced reactions were measured with the activation method in the 37-65MeV energy range on natural holmium. Stacked foil irradiation technique and high resolution gamma spectrometry were used in order to measure cross-section data for the production of (161)Er, (160)Er and (1)(59,157)Dy. For comparison of the production routes of medically related (161)Er and (160)Er radioisotopes new experimental cross section data were deduced for the (162)Er(p,x)(161,160)Er and (162)Er(d,x)(161,160)Er reactions by re-evaluating gamma-ray spectra from earlier measurements. No earlier data were found in the literature for these reactions. The experimental data are compared with results of TALYS theoretical code reported in TENDL-2015.

  4. Evaluation of the production capabilities of 18F, 11C, 13N and 15O PET isotopes at the PET-cyclotron-radiochemistry site of Messina University

    Directory of Open Access Journals (Sweden)

    Lucrezia Auditore

    2017-02-01

    Full Text Available The production of 18F, 11C, 13N, and 15O positron emitting radionuclides for PET imaging is usually accomplished in Nuclear Medicine Departments through direct nuclear reactions induced by protons accelerated by compact medical cyclotrons on liquid or gaseous targets. Messina University has funded the construction of a PET-cyclotron-radio-chemistry plant at the Messina University Hospital, equipped with a 11 MeV self-shielded cyclotron. We estimated the expected production yields of these nuclides, accounting for target thickness, production of other radioactive nuclides, and time effects on the irradiated target purity. To this aim, both TALYS code (v. 1.8 and an analytical approach based on EXFOR experimental data were used. The general agreement between the two approaches, and with the available literature data, allows to assess the expected yields at the End of Bombardment, and relative target purities, to be used for further radiopharmaceutical preparation steps.

  5. Production of cosmogenic isotopes 7Be, 10Be, 14C, 22Na and 36Cl in the atmosphere: Altitudinal profiles of yield functions

    CERN Document Server

    Poluianov, Stepan; Mishev, Alexander L; Usoskin, Ilya G

    2016-01-01

    New consistent and precise computations of the production of five cosmogenic radio-isotopes, 7Be, 10Be, 14C, 22Na and 36Cl, in the Earth's atmosphere by cosmic rays are presented in the form of tabulated yield functions. For the first time, a detailed set of the the altitude profiles of the production functions is provided which makes it possible to apply the results directly as input for atmospheric transport models. Good agreement with most of the earlier published works for columnar and global isotopic production rates is shown. Altitude profiles of the production are important, in particular for such tasks as studies of strong solar particle events in the past, precise reconstructions of solar activity on long-term scale, tracing air-mass dynamics using cosmogenic radio-isotopes, etc. As an example, computations of the $^{10}$Be deposition flux in the polar region are shown for the last decades and also for a period around 780 AD and confronted with the actual measurements in Greenland and Antarctic ice c...

  6. Response of LaBr{sub 3}(Ce) scintillators to 14 MeV fusion neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Cazzaniga, C., E-mail: carlo.cazzaniga@mib.infn.it [University of Milano Bicocca, Departement of Physics, Piazza della Scienza 3, Milano 20125 (Italy); Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, via Roberto Cozzi 53, Milano 20125 (Italy); Nocente, M. [University of Milano Bicocca, Departement of Physics, Piazza della Scienza 3, Milano 20125 (Italy); Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, via Roberto Cozzi 53, Milano 20125 (Italy); Tardocchi, M. [Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, via Roberto Cozzi 53, Milano 20125 (Italy); Rebai, M. [University of Milano Bicocca, Departement of Physics, Piazza della Scienza 3, Milano 20125 (Italy); Pillon, M. [Associazione EURATOM-ENEA sulla Fusione ENEA C.R. Frascati, Via E. Fermi, 45, 00044 Frascati, Roma (Italy); Camera, F.; Giaz, A.; Pellegri, L. [University of Milano, Departement of Physics, Via Celoria 16, Milano 1-20133 (Italy); Gorini, G. [University of Milano Bicocca, Departement of Physics, Piazza della Scienza 3, Milano 20125 (Italy); Istituto di Fisica del Plasma, Associazione EURATOM-ENEA-CNR, via Roberto Cozzi 53, Milano 20125 (Italy)

    2015-04-01

    The response of a 3″×3″ LaBr{sub 3}(Ce) scintillator to 14 MeV neutron irradiation has been measured at the Frascati Neutron Generator and simulated by means of a dedicated MCNP model. Several reactions are found to contribute to the measured response, with a key role played by neutron inelastic scattering and (n,2n) reactions on {sup 79}Br, {sup 81}Br and {sup 139}La isotopes. An overall 43% efficiency to 14 MeV neutron detection above an experimental threshold of 0.35 MeV is calculated and confirmed by measurements. Post irradiation activation of the crystal has been also observed and is explained in terms of nuclear decays from the short lived {sup 78}Br and {sup 80}Br isotopes produced in (n,2n) reactions. The results presented in this paper are of relevance for the design of γ-ray detectors in burning plasma fusion experiments of the next generation, such as ITER, where capability to perform measurements in an intense 14 MeV neutron flux is required.

  7. The effect of the changing solar system environment on galactic cosmic ray propagation through the heliosphere: Consequences for cosmogenic isotope production in the Earth's atmosphere.

    Science.gov (United States)

    Axford, W. I.; Florinski, V.; Zank, G. P.

    2004-12-01

    The solar system is traveling through highly inhomogeneous interstellar medium. Our galactic environment (the Local Bubble) is a vast region formed by supernova explosions filled with extremely tenuous fully ionized gas at a temperature of over a million K. Embedded in the Local Bubble are interstellar clouds ranging from cold (Twarm (T ˜ 104 K) and relatively tenuous (n ˜ 0.3 cm-1) partially ionized clouds, such as the Local Cloud where the Sun is currently located. The properties of the cloud control the size and shape of the heliosphere and, consequently, affect the propagation of galactic cosmic rays (GCRs) between the boundary of the modulation region (the heliopause) and Earth. GCRs with energies above several hundred MeV initiate nuclear reactions in the Earth's upper atmosphere producing radioactive isotopes of Beryllium and Carbon that are precipitated on the surface and eventually incorporated into sediments. It is then quite plausible that the history of the variability of the solar environment may be preserved in cosmogenic isotope records available from ice and sea sediment cores dating back more than 100,000 years. Previously, we showed that increasing the density of the cloud surrounding the solar system by a factor of 30 leads to an increase in 1 AU GCR fluxes by a factor of 1.5--3, and that cloud encounters may have been responsible for the observed peaks in 10Be records 35 and 60 thousand years ago. Extending our early model, we now calculate GCR distribution from the solution of the 2D Parker equation using the global model-calculated plasma and magnetic field parameters as a background to determine the diffusion coefficients. Initial results from a more comprehensive investigation of the global structure of the heliosphere embedded in clouds of varying density, from the present conditions in the Local Cloud to the extreme case of dense molecular clouds, are discussed.

  8. Oxygen isotope studies of phosphite oxidation: purification and analysis of reactants and products by high-temperature conversion elemental analyzer/isotope ratio mass spectrometry.

    Science.gov (United States)

    Chang, Sae Jung; Blake, Ruth E

    2015-11-15

    Increased attention has been recently focused on the origin and reactions of reduced-P oxyanions such as phosphite [PO3 (III)] in terrestrial and biological systems. We present new methods for studying O-isotopic reactions between PO3 (III) and other oxygen sources during oxidation of PO3 (III) to PO4 (V). Na2 (HPO3 )·5H2 O, used as a PO3 (III) source, contains structural water due to its hygroscopic nature; thus, we developed a method for determining the δ(18) O value of PO3 (III) after the removal of structural water. Next, we tested two techniques for purifying PO4 (V) from aqueous PO3 (III)/PO4 (V) mixtures: (1) precipitation of PO4 (V) as ammonium phosphomolybdate (APM); and (2) precipitation of PO4 (V) as magnesium ammonium phosphate (MAP). The O-isotope compositions, (18) O:(16) O (δ(18) O values), of Na2 (HPO3 ) and Ag3 PO4 were analyzed by TC/EA/IRMS. Structural water was removed from Na2 (HPO3 )·5H2 O after drying at 100 °C under vacuum and the δ(18) O value of PO3 (III) was obtained. The δ(18) O values of PO4 (V), which was extracted from (18) O-labeled PO3 (III)/PO4 (V) mixtures by APM and MAP precipitations, were not altered by the precipitation process. This result confirms that PO3 (III) is not converted into PO4 (V) by oxidation or hydrolysis under either strong acidic/oxidizing (APM) or alkaline (MAP) conditions for up to a 24-h period. We conclude that both APM and MAP precipitation are reliable and effective methods for the separation and purification of PO4 (V) from aqueous PO3 (III)/PO4 (V) mixtures. The methods described here will permit the study of the isotopic evolution of various pathways of geochemical as well as biological PO3 (III) oxidation. Copyright © 2015 John Wiley & Sons, Ltd.

  9. Radio-isotope production scale-up at the University of Wisconsin

    Energy Technology Data Exchange (ETDEWEB)

    Nickles, Robert Jerome [Univ of Wisconsin

    2014-06-19

    Our intent has been to scale up our production capacity for a subset of the NSAC-I list of radioisotopes in jeopardy, so as to make a significant impact on the projected national needs for Cu-64, Zr-89, Y-86, Ga-66, Br-76, I-124 and other radioisotopes that offer promise as PET synthons. The work-flow and milestones in this project have been compressed into a single year (Aug 1, 2012- July 31, 2013). The grant budget was virtually dominated by the purchase of a pair of dual-mini-cells that have made the scale-up possible, now permitting the Curie-level processing of Cu-64 and Zr-89 with greatly reduced radiation exposure. Mile stones: 1. We doubled our production of Cu-64 and Zr-89 during the grant period, both for local use and out-bound distribution to ≈ 30 labs nationwide. This involved the dove-tailing of beam schedules of both our PETtrace and legacy RDS cyclotron. 2. Implemented improved chemical separation of Zr-89, Ga-66, Y-86 and Sc-44, with remote, semi-automated dissolution, trap-and-release separation under LabView control in the two dual-mini-cells provided by this DOE grant. A key advance was to fit the chemical stream with miniature radiation detectors to confirm the transfer operations. 3. Implemented improved shipping of radioisotopes (Cu-64, Zr-89, Tc-95m, and Ho-163) with approved DOT 7A boxes, with a much-improved FedEx shipping success compared to our previous steel drums. 4. Implemented broad range quantitative trace metal analysis, employing a new microwave plasma atomic emission spectrometer (Agilent 4200) capable of ppb sensitivity across the periodic table. This new instrument will prove essential in bringing our radiometals into FDA compliance needing CoA’s for translational research in clinical trials. 5. Expanded our capabilities in target fabrication, with the purchase of a programmable 1600 oC inert gas tube furnace for the smelting of binary alloy target materials. A similar effort makes use of our RF induction furnace, allowing

  10. Plasma chemical production of stable isotopes of germanium from its fluorides

    Science.gov (United States)

    Kornev, Roman; Sennikov, Peter

    2016-08-01

    The reduction process of 72GeF4 in hydrogen plasma of RF-discharge (13.56 MHz) was experimentally investigated. It was found that 72Ge, polyfluorogermanes and gaseous HF were the main products of conversion. The behavior of the main electroactive impurities and of metal impurities in the process of hydrogen reduction of 72GeF4 was considered. Based on the data of emission spectroscopy of chemically active plasma, assumptions were made about the main plasma-chemical reactions responsible for the process of hydrogen reduction of 72GeF4. A single crystal of n-type with concentration of charge carriers of Czochralski method after the process of zone recrystallization of 72Ge. Contribution to the topical issue "6th Central European Symposium on Plasma Chemistry (CESPC-6)", edited by Nicolas Gherardi, Ester Marotta and Cristina Paradisi

  11. Determination of the urinary cortisol production rate using (1,2,3,4-13C)cortisol. Isotope dilution analyses at very small enrichments.

    Science.gov (United States)

    Chapman, T E; Kraan, G P; Drayer, N M; Nagel, G T; Wolthers, B G

    1987-02-01

    An isotope dilution mass spectrometric method to determine the urinary cortisol production rate (CPR) in babies and children is described. The method uses stable isotopically labelled (1,2,3,4-13C)cortisol. The tracer is intravenously administered to the patient and urine is collected for the following three days. Following extraction, enzymic hydrolysis, purification and isolation by high-performance liquid chromatography (HPLC) the urinary cortisol metabolites tetrahydrocortisone, tetrahydrocortisol, alpha- and beta-cortolone are separately oxidized the common product, 11-oxo-aetiocholanolone. The methyl oxime tert-butyldimethylsilyl ether derivative (MO TBDMS) was analysed by gas chromatography mass spectrometry. Quantification of the isotope enrichment was carried out by unlabelled, and at m/z 348 for labelled 11-oxo-aetiocholanolone. HPLC isolation of the metabolites together with the oxidation step allowed very small isotope enrichments, sometimes down to 0.1% (1:1000), to be reliably measured against a linear calibration graph containing 0 to 1% (13C4) enrichments. The standards for the calibration graph were synthesized from mixtures of labelled (13C4) cortisol and natural cortisol, and the calibration graph was prepared each time samples were measured. The long term instrumental precision of the isotope dilution analyses was 0.91% for a derivatized sample containing a (13C4) enrichment of 0.5% (measured on six different days over seven months). The coefficient of variation of the complete procedure for the four cortisol metabolites was between 1.17 and 2.14%. The clinical applicability of the method is demonstrated by presenting the results of a CPR determination in a patient.

  12. Determining the isotopic compositions of uranium and fission products in radioactive environmental microsamples using laser ablation ICP-MS with multiple ion counters

    Energy Technology Data Exchange (ETDEWEB)

    Boulyga, Sergei F.; Prohaska, Thomas [University of Natural Resources and Applied Life Sciences, Department of Chemistry, Division of Analytical Chemistry-VIRIS Laboratory, Vienna (Austria)

    2008-01-15

    This paper presents the application of a multicollector inductively coupled plasma mass spectrometer (MC-ICP-MS) - a Nu Plasma HR - equipped with three ion-counting multipliers and coupled to a laser ablation system (LA) for the rapid and sensitive determination of the {sup 235}U/{sup 238}U, {sup 236}U/{sup 238}U, {sup 145}Nd/{sup 143}Nd, {sup 146}Nd/{sup 143}Nd, {sup 101}Ru/({sup 99}Ru+{sup 99}Tc) and {sup 102}Ru/({sup 99}Ru+{sup 99}Tc) isotope ratios in microsamples collected in the vicinity of Chernobyl. Microsamples with dimensions ranging from a hundred {mu}m to about 1 mm and with surface alpha activities of 3-38 mBq were first identified using nuclear track radiography. U, Nd and Ru isotope systems were then measured sequentially for the same microsample by LA-MC-ICP-MS. The application of a zoom ion optic for aligning the ion beams into the ion counters allows fast switching between different isotope systems, which enables all of the abovementioned isotope ratios to be measured for the same microsample within a total analysis time of 15-20 min (excluding MC-ICP-MS optimization and calibration). The {sup 101}Ru/({sup 99}Ru+{sup 99}Tc) and {sup 102}Ru/({sup 99}Ru+{sup 99}Tc) isotope ratios were measured for four microsamples and were found to be significantly lower than the natural ratios, indicating that the microsamples were contaminated with the corresponding fission products (Ru and Tc). A slight depletion in {sup 146}Nd of about 3-5% was observed in the contaminated samples, but the Nd isotopic ratios measured in the contaminated samples coincided with natural isotopic composition within the measurement uncertainty, as most of the Nd in the analyzed samples originates from the natural soil load of this element. The {sup 235}U/{sup 238}U and {sup 236}U/{sup 238}U isotope ratios were the most sensitive indicators of irradiated uranium. The present work yielded a significant variation in uranium isotope ratios in microsamples, in contrast with previously

  13. Systematization of cross sections for the production of residual nuclei on separated tin isotopes in reactions induced by various-energy protons

    Energy Technology Data Exchange (ETDEWEB)

    Balabekyan, A. R., E-mail: balabekyan@ysu.am; Danagulyan, A. S. [Yerevan State University (Armenia); Drnoyan, J. R.; Demekhina, N. A. [Joint Institute for Nuclear Research (Russian Federation); Hovhannisyan, G. H.; Simonyan, A. E. [Yerevan State University (Armenia); Adam, J.; Solnishkin, A. A.; Tsoupko-Sytnikov, V. M. [Joint Institute for Nuclear Research (Russian Federation)

    2011-05-15

    Cross sections for the production of residual nuclei on the isotopes {sup 112,118,120,124}Sn irradiated with 0.66-, 1.0-, 3.65-, and 8.1-GeV proton beams were investigated. A ten-parameter semiempirical formula was used to systematize the cross sections in question. A comparative analysis of parameter values obtained at different proton energies was performed.

  14. Beta-Decay Half-Lives and Neutron-Emission Probabilities of Very Neutron-Rich Y to Tc Isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Mehren, T.; Pfeiffer, B.; Schoedder, S.; Kratz, K. [Institut fuer Kernchemie, Universitaet Mainz, D-55099 Mainz (Germany); Huhta, M.; Dendooven, P.; Honkanen, A.; Lhersonneau, G.; Oinonen, M.; Parmonen, J.; Penttilae, H.; Popov, A.; Rubchenya, V.; Aeystoe, J. [Department of Physics, Accelerator Laboratory, University of Jyvaeskylae, FIN-40351 Jyvaeskylae (Finland)

    1996-07-01

    Neutron-rich {sub 39}Y to {sub 43}Tc isotopes have been produced by fission of uranium with a 50MeV H{sub 2}{sup +} beam. Beta-decay half-lives, delayed neutron-emission probabilities, and production yields have been measured and compared with theory. Beta decay of 4 new isotopes is reported, and the {beta}-delayed neutron-emission mode has been discovered for 12 isotopes of the elements niobium and technetium. The results compared to quasiparticle random phase approximation predictions indicate the increasing importance of fast {beta} transitions to high-lying states of nuclei with large neutron excess. {copyright} {ital 1996 The American Physical Society.}

  15. Report to the Nuclear energy Research Advisory Committee (NERAC) Subcommittee on "Long-Term Isotope Research and Productions Plan" - Responses to Questions

    Energy Technology Data Exchange (ETDEWEB)

    Ammoniums

    1999-07-01

    This report presents responses to two series of questions that were raised by a subcommittee of the Nuclear Energy Research Advisory Committee (NERAC) that has been charged with producing a ''Long-Term Isotope Research and Production Plan.'' The NERAC subcommittee is chaired by Dr. Richard Reba, and the Hanford Site Visit team, which comprises a subset of the subcommittee members, is chaired by Dr. Thomas Ruth. The first set of questions raised by the subcommittee on isotope production at the Hanford Site was received from Dr. Ruth on May 10, 1999, and the second set was received from him on July 5, 1999. Responses to the first set of questions were prepared as part of a June 1999 report entitled ''Isotope Production at the Hanford Site in Richland, Washington'' (PNNL 1999a). The responses to these questions are summarized in this document, with frequent references to the June 1999 report for additional details. Responses to the second set of questions from the NERAC subcommittee are presented in this document for the first time.

  16. Study on hydrogen isotope permeation in the HTTR hydrogen production system. 2. Effectiveness of reducing the amount of permeated deuterium by oxidized film. Contract research

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Tetsuaki; Nishihara, Tetsuo [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment; Iwatsuki, Jin [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

    2002-11-01

    The Japan Atomic Energy Research Institute (JAERI) has performed a research and development (R and D) program on nuclear production of hydrogen as a study consigned by Ministry of Education, Culture, Sports, Science and Technology. Permeation of hydrogen isotope through a high-temperature alloy as used a heat transfer pipe of an intermediate heat exchanger and a steam reformer is an important problem in the hydrogen production system connected to be the high-temperature engineering test reactor (HTTR). In order to obtain detailed data for safety review and development of analytical codes, a test of permeation of hydrogen isotope was carried out as one of essential tests. The objective of this study is to obtain a permeability of hydrogen isotope through Hastelloy XR and other high temperature alloys and to evaluate quantitatively an effect of oxidized film on reducing the amount of permeated hydrogen through the pipe. From the results obtained in this experiment, it is supposed that the oxidized film produced on the surface of the heat transfer pipe during an early stage of the reactor operation will reduce the amount of tritium permeated from the primary circuit of the HTTR to the utilization system. This report describes the amount of permeated hydrogen and deuterium through Hastelloy XR with oxidized film on the tube surface and state for production of oxidized film. (author)

  17. Isotopic Abundances and Ratios in Arsenic Irradiated by High-Energy Neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Parker, W. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hall, J. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2010-06-07

    This document provides derivations of the 73As, 74As and 75As isotopic abundances and ratios in an arsenic sample irradiated by high-energy (14 MeV) neutrons for 0 ≤ t ≤ T, where T is short compared to the natural decay times of the reaction products (t1/2 (73As) ~ 80.3 d, t1/2 (74As) ~ 17.8 d). The document also outlines the historic approach used to analyze arsenic data from experiments.

  18. Sr isotope tracing of aquifer interactions in an area of accelerating coal-bed methane production, Powder River Basin, Wyoming

    Energy Technology Data Exchange (ETDEWEB)

    Frost, C.D.; Pearson, B.N.; Ogle, K.M.; Heffern, E.L.; Lyman, R.M. [University of Wyoming, Laramie, WY (United States). Dept. of Geology & Geophysics

    2002-07-01

    Sr isotope data on groundwater samples from coal and overlying sandstone aquifers in the eastern Powder River Basin, Wyoming, demonstrate that the Sr isotope ratio effectively identifies groundwater from different aquifers where major ion geochemistry and 0 and H stable isotope data fail. Groundwaters from sandstone aquifers have a uniform Sr-87/Sr-86 ratio of 0.7126-0.7127. Waters from coal seams vary from Sr-87/Sr-86 ratio = 0.7127 near the recharge area to 0.7151 farther into the basin. The distinct Sr isotope signatures of sandstone and coal aquifers may reflect different sources of Sr in these two rock types: Sr in sandstones is held primarily in carbonate cement, whereas coals contain more radiogenic Sr in organic matter. The Sr isotope ratio is useful in identifying wells that contain mixed waters, whether due to well construction or to incomplete aquifer isolation. Measurement and continued monitoring of the Sr isotope ratio in groundwaters should provide a powerful tool for characterizing the impact of the burgeoning coal-bed methane industry on the hydrology of the Powder River Basin.

  19. Fast-neutron induced pre-equilibrium reactions on 55Mn and 63,65Cu at energies up to 40 MeV

    CERN Document Server

    Avrigeanu, M; Filatenkov, A A; Forrest, R A; Herman, M; Köning, A J; Plompen, A J M; Roman, F L; Avrigeanu, V

    2007-01-01

    Excitation functions were measured for the $^{55}$Mn(n,2n)$^{54}$Mn, $^{55}$Mn(n,$\\alpha$)$^{52}$V, $^{63}$Cu(n,$\\alpha$)$^{60}$Co, $^{65}$Cu(n,2n)$^{64}$Cu, and $^{65}$Cu(n,p)$^{65}$Ni reactions from 13.47 to 14.83 MeV. The experimental cross sections are compared with the results of calculations including all activation channels for the stable isotopes of Mn and Cu, for neutron incident energies up to 50 MeV. Within the energy range up to 20 MeV the model calculations are most sensitive to the parameters related to nuclei in the early stages of the reaction, while the model assumptions are better established by analysis of the data in the energy range 20-40 MeV. While the present analysis has taken advantage of both a new set of accurate measured cross sections around 14 MeV and the larger data basis fortunately available between 20 and 40 MeV for the Mn and Cu isotopes, the need of additional measurements below as well as above 40 MeV is pointed out. Keywords: 55Mn, 63,65Cu, E$\\leq$40 MeV, Neutron activati...

  20. Measurement of the Am241(n,2n) reaction cross section from 7.6 MeV to 14.5 MeV

    Science.gov (United States)

    Tonchev, A. P.; Angell, C. T.; Boswell, M.; Crowell, A. S.; Fallin, B.; Hammond, S.; Howell, C. R.; Hutcheson, A.; Karwowski, H. J.; Kelley, J. H.; Pedroni, R. S.; Tornow, W.; Becker, J. A.; Dashdorj, D.; Kenneally, J.; Macri, R. A.; Stoyer, M. A.; Wu, C. Y.; Bond, E.; Chadwick, M. B.; Fitzpatrick, J.; Kawano, T.; Rundberg, R. S.; Slemmons, A.; Vieira, D. J.; Wilhelmy, J. B.

    2008-05-01

    The (n,2n) cross section of the radioactive isotope Am241 (T1/2=432.6 y) has been measured in the incident neutron energy range from 7.6 to 14.5 MeV in steps of a few MeV using the activation technique. Monoenergetic neutron beams were produced via the H2(d,n)He3 reaction by bombarding a pressurized deuterium gas cell with an energetic deuteron beam at the TUNL 10-MV Van de Graaff accelerator facility. The induced γ-ray activity of Am240 was measured with high-resolution HPGe detectors. The cross section was determined relative to Al, Ni, and Au neutron activation monitor foils, measured in the same geometry. Good agreement is obtained with previous measurements at around 9 and 14 MeV, whereas for a large discrepancy is observed when our data are compared to those reported by Perdikakis near 11 MeV. Very good agreement is found with the END-B/VII evaluation, whereas the JENDL-3.3 evaluation is in fair agreement with our data.

  1. Photonuclear reactions on titanium isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Belyshev, S. S. [Moscow State University (Russian Federation); Dzhilavyan, L. Z. [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation); Ishkhanov, B. S.; Kapitonov, I. M. [Moscow State University (Russian Federation); Kuznetsov, A. A., E-mail: kuznets@depni.sinp.msu.ru; Orlin, V. N.; Stopani, K. A. [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation)

    2015-03-15

    The photodisintegration of titanium isotopes in the giant-dipole-resonance energy region is studied by the photon-activation method. Bremsstrahlung photons whose spectrum has the endpoint energy of 55 MeV is used. The yields and integrated cross sections are determined for photoproton reactions on the titanium isotopes {sup 47,48,49,50}Ti. The respective experimental results are compared with their counterparts calculated on the basis of the TALYS code and a combined photonucleon-reaction model. The TALYS code disregards the isospin structure of the giant dipole resonance and is therefore unable to describe the yield of photoproton reactions on the heavy titanium isotopes {sup 49,50}Ti.

  2. Combining functional weed ecology and crop stable isotope ratios to identify cultivation intensity: a comparison of cereal production regimes in Haute Provence, France and Asturias, Spain.

    Science.gov (United States)

    Bogaard, Amy; Hodgson, John; Nitsch, Erika; Jones, Glynis; Styring, Amy; Diffey, Charlotte; Pouncett, John; Herbig, Christoph; Charles, Michael; Ertuğ, Füsun; Tugay, Osman; Filipovic, Dragana; Fraser, Rebecca

    This investigation combines two independent methods of identifying crop growing conditions and husbandry practices-functional weed ecology and crop stable carbon and nitrogen isotope analysis-in order to assess their potential for inferring the intensity of past cereal production systems using archaeobotanical assemblages. Present-day organic cereal farming in Haute Provence, France features crop varieties adapted to low-nutrient soils managed through crop rotation, with little to no manuring. Weed quadrat survey of 60 crop field transects in this region revealed that floristic variation primarily reflects geographical differences. Functional ecological weed data clearly distinguish the Provence fields from those surveyed in a previous study of intensively managed spelt wheat in Asturias, north-western Spain: as expected, weed ecological data reflect higher soil fertility and disturbance in Asturias. Similarly, crop stable nitrogen isotope values distinguish between intensive manuring in Asturias and long-term cultivation with minimal manuring in Haute Provence. The new model of cereal cultivation intensity based on weed ecology and crop isotope values in Haute Provence and Asturias was tested through application to two other present-day regimes, successfully identifying a high-intensity regime in the Sighisoara region, Romania, and low-intensity production in Kastamonu, Turkey. Application of this new model to Neolithic archaeobotanical assemblages in central Europe suggests that early farming tended to be intensive, and likely incorporated manuring, but also exhibited considerable variation, providing a finer grained understanding of cultivation intensity than previously available.

  3. Nitrogen isotopic evidence for a shift from nitrate- to diazotroph-fueled export production in the VAHINE mesocosm experiments

    Science.gov (United States)

    Knapp, Angela N.; Fawcett, Sarah E.; Martínez-Garcia, Alfredo; Leblond, Nathalie; Moutin, Thierry; Bonnet, Sophie

    2016-08-01

    In a coastal lagoon with a shallow, 25 m water column off the southwest coast of New Caledonia, large-volume ( ˜ 50 m3) mesocosm experiments were undertaken to track the fate of newly fixed nitrogen (N). The mesocosms were intentionally fertilized with 0.8 µM dissolved inorganic phosphorus to stimulate diazotrophy. N isotopic evidence indicates that the dominant source of N fueling export production shifted from subsurface nitrate (NO3-) assimilated prior to the start of the 23-day experiments to N2 fixation by the end of the experiments. While the δ15N of the sinking particulate N (PNsink) flux changed during the experiments, the δ15N of the suspended PN (PNsusp) and dissolved organic N (DON) pools did not. This is consistent with previous observations that the δ15N of surface ocean N pools is less responsive than that of PNsink to changes in the dominant source of new N to surface waters. In spite of the absence of detectable NO3- in the mesocosms, the δ15N of PNsink indicated that NO3- continued to fuel a significant fraction of export production (20 to 60 %) throughout the 23-day experiments, with N2 fixation dominating export after about 2 weeks. The low rates of organic N export during the first 14 days were largely supported by NO3-, and phytoplankton abundance data suggest that sinking material primarily comprised large diatoms. Concurrent molecular and taxonomic studies indicate that the diazotroph community was dominated by diatom-diazotroph assemblages (DDAs) at this time. However, these DDAs represented a minor fraction (< 5 %) of the total diatom community and contributed very little new N via N2 fixation; they were thus not important for driving export production, either directly or indirectly. The unicellular cyanobacterial diazotroph, a Cyanothece-like UCYN-C, proliferated during the last phase of the experiments when N2 fixation, primary production, and the flux of PNsink increased significantly, and δ15N budgets reflected a predominantly

  4. International challenge to predict the impact of radioxenon releases from medical isotope production on a comprehensive nuclear test ban treaty sampling station

    Energy Technology Data Exchange (ETDEWEB)

    Eslinger, Paul W.; Bowyer, Ted W.; Achim, Pascal; Chai, Tianfeng; Deconninck, Benoit; Freeman, Katie; Generoso, Sylvia; Hayes, Philip; Heidmann, Verena; Hoffman, Ian; Kijima, Yuichi; Krysta, Monika; Malo, Alain; Maurer, Christian; Ngan, Fantine; Robins, Peter; Ross, J. Ole; Saunier, Olivier; Schlosser, Clemens; Schöppner, Michael; Schrom, Brian T.; Seibert, Petra; Stein, Ariel F.; Ungar, Kurt; Yi, Jing

    2016-06-01

    Abstract The International Monitoring System (IMS) is part of the verification regime for the Comprehensive Nuclear-Test-Ban-Treaty Organization (CTBTO). At entry-into-force, half of the 80 radionuclide stations will be able to measure concentrations of several radioactive xenon isotopes produced in nuclear explosions, and then the full network may be populated with xenon monitoring afterward (Bowyer et al., 2013). Fission-based production of 99Mo for medical purposes also releases radioxenon isotopes to the atmosphere (Saey, 2009). One of the ways to mitigate the effect of emissions from medical isotope production is the use of stack monitoring data, if it were available, so that the effect of radioactive xenon emissions could be subtracted from the effect from a presumed nuclear explosion, when detected at an IMS station location. To date, no studies have addressed the impacts the time resolution or data accuracy of stack monitoring data have on predicted concentrations at an IMS station location. Recently, participants from seven nations used atmospheric transport modeling to predict the time-history of 133Xe concentration measurements at an IMS station in Germany using stack monitoring data from a medical isotope production facility in Belgium. Participants received only stack monitoring data and used the atmospheric transport model and meteorological data of their choice. Some of the models predicted the highest measured concentrations quite well (a high composite statistical model comparison rank or a small mean square error with the measured values). The results suggest release data on a 15 min time spacing is best. The model comparison rank and ensemble analysis suggests that combining multiple models may provide more accurate predicted concentrations than any single model. Further research is needed to identify optimal methods for selecting ensemble members and those methods may depend on the specific transport problem. None of the submissions based only

  5. Changes of surface structure and elemental composition of Pd rod and collector of nuclear reaction products irradiated with 10-MeV γ-quanta in dense deuterium gas

    Science.gov (United States)

    Didyk, A. Yu.; Wiśniewski, R.; Wilczynska-Kitowska, T.

    2013-12-01

    A high-pressure chamber is filled with 1.2 kbar molecular deuterium (DHPC). The palladium rod saturated with deuterium is loaded inside the DHPC and irradiated with 10-MeV bremsstrahlung γ-quanta for 18 h with a 11-13 μA electron beam using the MT-25 electron accelerator. The elemental compositions of all surfaces of the DHPC element inside the dense deuterium gas were studied using scanning electronic microscopes with X-ray microelement microprobe analysis. It is found that all surfaces, including the surface of a high-purity palladium rod (99.995%), are covered with a partly homogeneous layer or large microparticles of lead. Also, light elements such as 6C, 8O, 11Na, 12Mg, 13Al, 14Si, 22Ti, 25Mn, 26Fe, 29Cu, and 30Zn and heavy metals such as 47Ag, 73Ta, 74W, 78Pt, 79Au, and 82Pb are observed. Possible processes that can cause the anomalies observed in the newly formed chemical elements are briefly discussed.

  6. <600> MeV synchro-cyclotron

    CERN Multimedia

    1971-01-01

    One of the 14 pancakes of the new magnet coils for the 600 MeV synchro-cyclotron which were wound and coated with epoxy resin on the CERN site. These new coils will replace the present ones which have been in use for more than 14 years but are now showing signs of deteriorations.

  7. Result analysis of area monitoring realized in the 18 MeV cyclotron, during the process of fluorine-18 production; Analise dos resultados do monitoramento de area, realizada no ciclotron de 18 MeV, durante o processo de producao de fluor-18

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Paula P. Nou; Fernandes, Ivani M.; Silva, Amanda J. da; Rodrigues, Demerval Leonidas; Romero Filho, Christovam R., E-mail: paulanou@usp.b, E-mail: imfernades@ipen.b, E-mail: dlrodri@ipen.b, E-mail: ajsilva@ipen.b, E-mail: cromero@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-10-26

    This paper presents the results obtained through the monitoring of circulation area of cyclotron accelerators installation, during the operation for production of fluorine-18. Tis study was based on the data obtained by area monitoring during the year 2009. For determination of the dose rate it was used gamma and neutron radiation detectors. The measurements were performed in nine pre-determined points by the radioprotection team, giving a total of 282 measurements in each point. With the obtained results, it was verified that the area monitoring is accomplishing with his objective which is to now the levels of dose at the work places and, therefore, it is possible to prevent the doses which will be accumulated by the IOEs during the development of their tasks

  8. Protein retention assessment of four levels of poultry by-product substitution of fishmeal in rainbow trout (Oncorhynchus mykiss diets using stable isotopes of nitrogen (δ15N as natural tracers.

    Directory of Open Access Journals (Sweden)

    Daniel Badillo

    Full Text Available This is second part from an experiment where the nitrogen retention of poultry by-product meal (PBM compared to fishmeal (FM was evaluated using traditional indices. Here a quantitative method using stable isotope ratios of nitrogen (δ(15N values as natural tracers of nitrogen incorporation into fish biomass is assessed. Juvenile rainbow trout (Oncorhynchus mykiss were fed for 80 days on isotopically distinct diets in which 0, 33, 66 and 100% of FM as main protein source was replaced by PBM. The diets were isonitrogenous, isolipidic and similar in gross energy content. Fish in all treatments reached isotopic equilibrium by the end of the experiment. Two-source isotope mixing models that incorporated the isotopic composition of FM and PBM as well as that of formulated feeds, empirically derived trophic discrimination factors and the isotopic composition of fish that had reached isotopic equilibrium to the diets were used to obtain a quantitative estimate of the retention of each source of nitrogen. Fish fed the diets with 33 and 66% replacement of FM by PBM retained poultry by-product meal roughly in proportion to its level of inclusion in the diets, whereas no differences were detected in the protein efficiency ratio. Coupled with the similar biomass gain of fishes fed the different diets, our results support the inclusion of PBM as replacement for fishmeal in aquaculture feeds. A re-feeding experiment in which all fish were fed a diet of 100% FM for 28 days indicated isotopic turnover occurred very fast, providing further support for the potential of isotopic ratios as tracers of the retention of specific protein sources into fish tissues. Stable isotope analysis is a useful tool for studies that seek to obtain quantitative estimates of the retention of different protein sources.

  9. Titanium carbide-carbon porous nanocomposite materials for radioactive ion beam production: processing, sintering and isotope release properties

    CERN Document Server

    AUTHOR|(CDS)2081922; Stora, Thierry

    2017-01-26

    The Isotope Separator OnLine (ISOL) technique is used at the ISOLDE - Isotope Separator OnLine DEvice facility at CERN, to produce radioactive ion beams for physics research. At CERN protons are accelerated to 1.4 GeV and made to collide with one of two targets located at ISOLDE facility. When the protons collide with the target material, nuclear reactions produce isotopes which are thermalized in the bulk of the target material grains. During irradiation the target is kept at high temperatures (up to 2300 °C) to promote diffusion and effusion of the produced isotopes into an ion source, to produce a radioactive ion beam. Ti-foils targets are currently used at ISOLDE to deliver beams of K, Ca and Sc, however they are operated at temperatures close to their melting point which brings target degradation, through sintering and/or melting which reduces the beam intensities over time. For the past 10 years, nanostructured target materials have been developed and have shown improved release rates of the produced i...

  10. PRODUCTION AND TRANSPORT OF CARBON DIOXIDE IN A CONTAMINATED VADOSE ZONE: A STABLE AND RADIOACTIVE CARBON ISOTOPE STUDY

    Science.gov (United States)

    Analyses of soil gas compositions and stable and radioactive carbon isotopes in the vadose zone above an alluvial aquifer were conducted at an organic solvent disposal site in southeast Phoenix, AZ. The study investigated the source and movement of carbon dioxide above a plume of...

  11. Determination of Glyphosate, its Degradation Product Aminomethylphosphonic Acid, and Glufosinate, in Water by Isotope Dilution and Online Solid-Phase Extraction and Liquid Chromatography/Tandem Mass Spectrometry

    Science.gov (United States)

    Meyer, Michael T.; Loftin, Keith A.; Lee, Edward A.; Hinshaw, Gary H.; Dietze, Julie E.; Scribner, Elisabeth A.

    2009-01-01

    The U.S. Geological Survey method (0-2141-09) presented is approved for the determination of glyphosate, its degradation product aminomethylphosphonic acid (AMPA), and glufosinate in water. It was was validated to demonstrate the method detection levels (MDL), compare isotope dilution to standard addition, and evaluate method and compound stability. The original method USGS analytical method 0-2136-01 was developed using liquid chromatography/mass spectrometry and quantitation by standard addition. Lower method detection levels and increased specificity were achieved in the modified method, 0-2141-09, by using liquid chromatography/tandem mass spectrometry (LC/MS/MS). The use of isotope dilution for glyphosate and AMPA and pseudo isotope dilution of glufosinate in place of standard addition was evaluated. Stable-isotope labeled AMPA and glyphosate were used as the isotope dilution standards. In addition, the stability of glyphosate and AMPA was studied in raw filtered and derivatized water samples. The stable-isotope labeled glyphosate and AMPA standards were added to each water sample and the samples then derivatized with 9-fluorenylmethylchloroformate. After derivatization, samples were concentrated using automated online solid-phase extraction (SPE) followed by elution in-line with the LC mobile phase; the compounds separated and then were analyzed by LC/MS/MS using electrospray ionization in negative-ion mode with multiple-reaction monitoring. The deprotonated derivatized parent molecule and two daughter-ion transition pairs were identified and optimized for glyphosate, AMPA, glufosinate, and the glyphosate and AMPA stable-isotope labeled internal standards. Quantitative comparison between standard addition and isotope dilution was conducted using 473 samples analyzed between April 2004 and June 2006. The mean percent difference and relative standard deviation between the two quantitation methods was 7.6 plus or minus 6.30 (n = 179), AMPA 9.6 plus or minus 8

  12. Time Constraints on Soil Evolution from Uranium-series Isotopes in the South-eastern Australian Highlands: Evidences for a Coupling Between Soil Erosion and Production

    Science.gov (United States)

    Puthiyaveetil Othayoth, S.; Dosseto, A.; Hesse, P. P.; Handley, H. K.

    2011-12-01

    The evolution of soil resources (steady-state, aggradation or degradation) is determined by the balance between soil production and denudation rates. The uranium-series isotopic composition of four soil profiles from Frogs Hollow, a location in the upper catchment area of the Murrumbidgee River in southeastern Australia, has been determined to constrain the soil production rate in this region. The results are compared with previous estimates of soil residence time at this site, estimated from cosmogenic radionuclides and soil elemental chemistry data. Soil is increasingly weathered from bottom to top, which is evident from the decrease in (234U/238U) ratios and increase in relative quartz content with decreasing soil depth. The observed variations in mineralogy and geochemistry between the four soil profiles reflect differences in the degree of weathering. Sequential leaching was conducted to assess how uranium-series isotopes are distributed between primary and secondary minerals. Leached and unleached aliquots show similar mineralogy with minor variation in the relative mineral abundances whereas the elemental and isotopic compositions of uranium and thorium show notable differences. The unleached samples show more systematic variations in uranium-series isotopic compositions with depth when compared to leached samples. Soil residence times are calculated by modeling soil uranium-series isotopic composition using the model from (Dosseto et al., 2008). Inferred values vary from 3 to 30 kyr for profiles F1 (unleached aliquots) and F2. A negative correlation is observed between muscovite abundance and calculated soil residence times. The slope of this correlation is similar for different soil profiles and for both leached and unleached aliquots. Thus, we were able to apply this relationship to profiles where the residence time could not be calculated due to scatter in U-series isotope compositions. The inferred soil residence times range from 3 to 33 kyr for leached

  13. Estimating evolution of δ(13)CH(4) during methanization of municipal solid waste based on chemical reactions, isotope accumulation in products and microbial ecology.

    Science.gov (United States)

    Vavilin, V A

    2012-01-01

    Natural isotopic composition in substrate may be used to reveal the metabolic pathways of substrate transformation by microbial community. In this paper, a change in δ(13)CH(4) during methanization of reconstituted municipal solid waste was described using a mathematical model based on stoichiometric chemical reactions, equation for the (13)C isotope accumulation in products at the low natural C(13)/C(12) ratio and microbial ecology. A set of experimental data used in the model was taken from Qu et al. (2009a). According to the model, during mesophilic municipal solid waste methanization initially hydrogenotrophic and further aceticlastic methanogenesis dominated. At the final stage hydrogenotrophic methanogenesis followed by acetate oxidation dominated again. In spite of rather high measured values of δ(13)C for CO(2) above -21‰, a sharp decrease in δ(13)CH(4) from -20‰ to -60‰ at the final stage was explained by a larger fractionation against (13)C during methanogenesis from H(2)/H(2)CO(3) due to a kinetic isotope effect when hydrogenotrophic methanogens preferentially take down light (12)C. The model also confirmed that in thermophilic conditions a comparatively stable value of δ(13)CH(4) about -60‰ measured earlier (Qu et al. 2009b) was due to a dominance of hydrogenotrophic methanogenesis during all methanization process of cardboard waste.

  14. Inter-comparison of High Energy Files (neutron-induced, from 20 to 150 MeV)

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young-Ouk; Fukahori, Tokio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-11-01

    Recent new applications using accelerator-driven system require well-tested nuclear data when modeling the interaction of neutrons above 20 MeV. This work is aimed to review evaluation methods applied in currently available neutron high energy files above 20 to 150 MeV, to inter-compare their evaluated cross sections on some important isotopes, and to analyze resulting discrepancies. Through out these, integrities and consistencies of the high energy files are checked, applicability of physics models and evaluation methodologies are assessed, and some directions are derived to improve and expand current JENDL High Energy File. (author)

  15. Empirical relation and establishment of shell effects in (, 2) reaction cross-sections at 14 MeV

    Indian Academy of Sciences (India)

    Sneh Lata Goyal; Pratibha Gur

    2009-02-01

    The experimental data for (, 2) reaction cross-sections around 14 MeV neutron energy have been collected from the literature and analysed for the isotopes having 1 ≤ ≤ 82. The empirical relations for the reaction cross-sections have been obtained, which show fairly good fits with the experimental values. The shell effects have been established at magic nucleon numbers for (, 2) reaction cross-sections around 14 MeV neutron energy. The odd–even effects have also been observed as the cross-sections for odd-mass nuclei are higher than their neighbouring even–even nuclei.

  16. Perchlorate isotope forensics

    Science.gov (United States)

    Böhlke, J.K.; Sturchio, N.C.; Gu, B.; Horita, J.; Brown, G.M.; Jackson, W.A.; Batista, J.; Hatzinger, P.B.

    2005-01-01

    Perchlorate has been detected recently in a variety of soils, waters, plants, and food products at levels that may be detrimental to human health. These discoveries have generated considerable interest in perchlorate source identification. In this study, comprehensive stable isotope analyses ( 37Cl/35Cl and 18O/17O/ 16O) of perchlorate from known synthetic and natural sources reveal systematic differences in isotopic characteristics that are related to the formation mechanisms. In addition, isotopic analyses of perchlorate extracted from groundwater and surface water demonstrate the feasibility of identifying perchlorate sources in contaminated environments on the basis of this technique. Both natural and synthetic sources of perchlorate have been identified in water samples from some perchlorate occurrences in the United States by the isotopic method. ?? 2005 American Chemical Society.

  17. The Mechanical Design and Preliminary Testing Results of Beam Position Monitors for the LANSCE Isotope Production Facility and Switchyard Kicker Projects

    Science.gov (United States)

    O'Hara, J. F.; Gilpatrick, J. D.; Ledford, J. E.; Shurter, R. B.; Roybal, R. J.; Bentley, B. E.

    2002-12-01

    The Los Alamos Neutron Science Center (LANSCE-1) Beam Diagnostic Team is providing Beam Position Monitors (BPMs) to the LANSCE Facility for use in two on-going projects: The Isotope Production Facility (IPF) and The Switchyard Kicker Upgrade (SYK). The BPM designs for both projects are very similar. The BPMs are classic, four, micro-stripline units having one end terminated in a 50-ohm load. This paper will discuss the position measurement requirements, mechanical design, fabrication, and alignment issues encountered for both sets of BPMs, as well as report the results obtained from the initial taught wire testing of the IPF BPMs.

  18. Origin and evolution of formation water at the Jujo-Tecominoacan oil reservoir, Gulf of Mexico. Part 2: Isotopic and field-production evidence for fluid connectivity

    Energy Technology Data Exchange (ETDEWEB)

    Birkle, Peter, E-mail: birkle@iie.org.mx [Instituto de Investigaciones Electricas (IIE), Gerencia de Geotermia, Cuernavaca 62490, Morelos (Mexico); Garcia, Bernardo Martinez; Milland Padron, Carlos M. [PEMEX Exploracion y Produccion, Region Sur, Activo Integral Bellota-Jujo, Diseno de Explotacion, Cardenas, Tabasco (Mexico); Eglington, Bruce M. [Saskatchewan Isotope Laboratory, University of Saskatchewan, Saskatoon, Canada SK S7N 5E2 (Canada)

    2009-04-15

    The chemical and isotopic characterization of formation water from 18 oil production wells, extracted from 5200 to 6100 m b.s.l. at the Jujo-Tecominoacan carbonate reservoir in SE-Mexico, and interpretations of historical production records, were undertaken to determine the origin and hydraulic behavior of deep groundwater systems. The infiltration of surface water during Late Pleistocene to Early Holocene time is suggested by {sup 14}C-concentrations from 2.15 to 31.86 pmC, and by {sup 87}Sr/{sup 86}Sr-ratios for high-salinity formation water (0.70923-0.70927) that are close to the composition of Holocene to modern seawater. Prior to infiltration, the super-evaporation of seawater reached maximum TDS concentrations of 385 g/L, with lowest {delta}{sup 18}O values characterizing the most hypersaline samples. Minor deviations of formation water and dolomite host rocks from modern and Jurassic {sup 87}Sr/{sup 86}Sr-seawater composition, respectively, suggest ongoing water-rock interaction, and partial isotopic equilibration between both phases. The abundance of {sup 14}C in all sampled formation water, {sup 87}Sr/{sup 86}Sr-ratios for high-salinity water close to Holocene - present seawater composition, a water salinity distribution that is independent of historic water-cut, and a total water extraction volume of 2.037 MMm{sup 3} (1/83-4/07) excludes a connate, oil-leg origin for the produced water of the Jurassic-Cretaceous mudstone-dolomite sequence. Temporal fluctuations of water chemistry in production intervals, the accelerated migration of water fronts from the reservoir flanks, and isotopic mixing trends between sampled wells confirms the existence of free aquifer water below oil horizons. Vertical and lateral hydraulic mobility has probably been accelerated by petroleum extraction. The combination of interpreting historical fluctuations of salinity and water percentage in production wells with chemical-isotopic analysis of formation water resulted in a

  19. Production cross sections from 82Se fragmentation as indications of shell effects in neutron-rich isotopes close to the drip-line

    CERN Document Server

    Tarasov, O B; Morrissey, D J; Amthor, A M; Bandura, L; Baumann, T; Bazin, D; Berryman, J S; Brown, B A; Chubarian, G; Fukuda, N; Gade, A; Ginter, T N; Hausmann, M; Inabe, N; Kubo, T; Pereira, J; Sherrill, B M; Stolz, A; Sumithrarachichi, C; Thoennessen, M; Weisshaar, D

    2013-01-01

    Production cross sections for neutron-rich nuclei from the fragmentation of a 82Se beam at 139 MeV/u were measured. The longitudinal momentum distributions of 126 neutron-rich isotopes of elements 11 <= Z <= 32 were scanned using an experimental approach of varying the target thickness. Production cross sections with beryllium and tungsten targets were determined for a large number of nuclei including several isotopes first observed in this work. These are the most neutron-rich nuclides of the elements 22 <= Z <= 25 (64Ti, 67V, 69Cr, 72Mn). One event was registered consistent with 70Cr, and another one with 75Fe. The production cross sections are correlated with Qg systematics to reveal trends in the data. The results presented here confirm our previous result from a similar measurement using a 76Ge beam, and can be explained with a shell model that predicts a subshell closure at N = 34 around Z = 20. This is demonstrated by systematic trends and calculations with the Abrasion-Ablation model that ...

  20. Study of calf thymus DNA irradiated in vitro with MeV fluorine ions

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A study of the fragments of DNA irradiated with MeV ions is important for the understanding of the DNA damage mechanism and the subsequent biological effects (induced by heavy ions). In this experiment, the products of calf thymus DNA (CT DNA) irradiated with MeV fluorine ions were analyzed using agarose gel electrophoresis,modified time-of-flight mass spectrometer (MALDI-TOF), and high-performance liquid chromatography (HPLC).The results showed that the molecular mass of the fragments were concentrated around 831 bp with agarose gel electrophoresis, there was no observable product in the range of 1,000- 30,000 (m/q) using MALDI-TOF, and small biomolecules were separated from the products. The results of this study indicated that the strand breaks of calf thymus DNA induced by MeV fluorine ions were nonrandom.

  1. Plutonium isotopes and their decay products in civil nuclear engineering; Les isotopes du plutonium et leurs descendants dans le nucleaire civil

    Energy Technology Data Exchange (ETDEWEB)

    Dautray, R

    2005-07-01

    This book is the continuation and conclusion of a previous book from the same author, entitled 'civil nuclear energy in the temporal framework of climatic changes' (Tec and Doc editions). It focusses on plutonium and on its daughter products. A synthesis of the scientific and technical data gathered so far is presented, together with the different choices offered to political authorities in the light of present-day knowledge. The authors starts from existing and firmly implemented scientific and technical data and presents some ways to solve the pending questions about the management of radioactive wastes. He shows that in our democratic system, the choice belongs to people. Beside the storage and deep disposal facilities, still necessary, some processes and problems are reviewed and explored. Of course new scientific data will be obtained, which would change the ways to discover and evaluate the ways to follow up. (J.S.)

  2. Exotic Structure of Carbon Isotopes

    CERN Document Server

    Suzuki, T; Hagino, K; Suzuki, Toshio; Sagawa, Hiroyuki; Hagino, Kouichi

    2002-01-01

    We studied firstly the ground state properties of C-isotopes using a deformed Hartree-Fock (HF)+ BCS model with Skyrme interactions. Shallow deformation minima are found in several neutron$-$rich C-isotopes. It is shown also that the deformation minima appear in both the oblate and the prolate sides in $^{17}$C and $^{19}$C having almost the same binding energies. Secondly, we carried out shell model calculations to study electromagnetic moments and electric dipole transitions of the C-isotopes. We point out the clear configuration dependence of the quadrupole and magnetic moments in the odd C-isotopes, which will be useful to find out the deformations and the spin-parities of the ground states of these nuclei. We studied electric dipole states of C-isotopes focusing on the interplay between low energy Pigmy strength and giant dipole resonances. Reasonable agreement is obtained with available experimental data for the photoreaction cross sections both in the low energy region below $\\hbar \\omega $=14 MeV and ...

  3. Silicon carbide grains of type C provide evidence for the production of the unstable isotope $^{32}$Si in supernovae

    CERN Document Server

    Pignatari, M; Bertolli, M G; Trappitsch, R; Hoppe, P; Rauscher, T; Fryer, C; Herwig, F; Hirschi, R; Timmes, F X; Thielemann, F -K

    2013-01-01

    Carbon-rich grains are observed to condense in the ejecta of recent core-collapse supernovae, within a year after the explosion. Silicon carbide grains of type X are C-rich grains with isotpic signatures of explosive supernova nucleosynthesis have been found in primitive meteorites. Much rarer silicon carbide grains of type C are a special sub-group of SiC grains from supernovae. They show peculiar abundance signatures for Si and S, isotopically heavy Si and isotopically light S, which appear to to be in disagreement with model predictions. We propose that C grains are formed mostly from C-rich stellar material exposed to lower SN shock temperatures than the more common type X grains. In this scenario, extreme $^{32}$S enrichments observed in C grains may be explained by the presence of short-lived $^{32}$Si ($\\tau$$_{1/2}$ = 153 years) in the ejecta, produced by neutron capture processes starting from the stable Si isotopes. No mixing from deeper Si-rich material and/or fractionation of Si from S due to mole...

  4. Design, construction, and operation of a laboratory scale reactorfor the production of high-purity, isotopically enriched bulksilicon

    Energy Technology Data Exchange (ETDEWEB)

    Ager III, J.W.; Beeman, J.W.; Hansen, W.L.; Haller, E.E.

    2004-12-20

    The design and operation of a recirculating flow reactor designed to convert isotopically enriched silane to polycrystalline Si with high efficiency and chemical purity is described. The starting material is SiF{sub 4}, which is enriched in the desired isotope by a centrifuge method and subsequently converted to silane. In the reactor, the silane is decomposed to silicon on the surface of a graphite starter rod (3 mm diameter) heated to 700-750 C. Flow and gas composition (0.3-0.5% silane in hydrogen) are chosen to minimize the generation of particles by homogeneous nucleation of silane and to attain uniform deposition along the length of the rod. Growth rates are 5 {micro}m/min, and the conversion efficiency is greater than 95%. A typical run produces 35 gm of polycrystalline Si deposited along a 150 mm length of the rod. After removal of the starter rod, dislocation-free single crystals are formed by the floating zone method. Crystals enriched in all 3 stable isotopes of Si have been made: {sup 28}Si (99.92%), {sup 29}Si (91.37%), and {sup 30}Si (88.25%). Concentrations of electrically active impurities (P and B) are as low as mid-10{sup 13} cm{sup -3}. Concentrations of C and O lie below 10{sup 16} and 10{sup 15} cm{sup -3}, respectively.

  5. Total and differential cross sections of the reaction p + d -> 3He + eta at 48.8 MeV and 59.8MeV excess energy

    CERN Document Server

    Adlarson, P; Bardan, W; Bashkanov, M; Bergmann, F S; Berłowski, M; Bhatt, H; Büscher, M; Calén, H; Ciepał, I; Clement, H; Coderre, D; Czerwiński, E; Demmich, K; Doroshkevich, E; Engels, R; Erven, A; Erven, W; Eyrich, W; Fedorets, P; Föhl, K; Fransson, K; Goldenbaum, F; Goslawski, P; Goswami, A; Grigoryev, K; Gullström, C --O; Hauenstein, F; Heijkenskjöld, L; Hejny, V; Hodana, M; Höistad, B; Hüsken, N; Jany, A; Jany, B R; Jarczyk, L; Johansson, T; Kamys, B; Kemmerling, G; Khan, F A; Khoukaz, A; Kirillov, D A; Kistryn, S; Kłos, B; Kleines, H; Krapp, M; Krzemień, W; Kulessa, P; Kupść, A; Lalwani, K; Lersch, D; Lorentz, B; Magiera, A; Maier, R; Marciniewski, P; Mariański, B; Mikirtychiants, M; Morsch, H --P; Moskal, P; Ohm, H; Ozerianska, I; Passfeld, A; del Rio, E Perez; Piskunov, N M; Podkopał, P; Prasuhn, D; Pricking, A; Pszczel, D; Pysz, K; Pyszniak, A; Redmer, C F; Ritman, J; Roy, A; Rudy, Z; Sawant, S; Schadmand, S; Sefzick, T; Serdyuk, V; Siudak, R; Skorodko, T; Skurzok, M; Smyrski, J; Sopov, V; Stassen, R; Stepaniak, J; Stephan, E; Sterzenbach, G; Stockhorst, H; Ströher, H; Szczurek, A; Täschner, A; Trzciński, A; Varma, R; Wagner, G J; Węglorz, W; Wolke, M; Wrońska, A; Wüstner, P; Wurm, P; Yamamoto, A; Yurev, L; Zabierowski, J; Zieliński, M J; Zink, A; Złomańczuk, J; Żuprański, P; Żurek, M

    2014-01-01

    We present new data for the cross section ratio of the p + d -> 3He + eta reaction at excess energies of Q = 48.8 MeV and Q = 59.8 MeV. The data have been obtained at the WASA-at-COSY experiment (Forschungszentrum J\\"ulich) using a proton beam and a deuterium pellet target. By using an ANKE data point at 59.4 MeV excess energy, an absolute normalization was performed and total and differential cross sections have been determined. While the shape of obtained angular distributions show only a slow variation with the energy, the new results indicate a distinct and unexpected total cross section fluctuation between Q = 20 MeV and Q = 60 MeV, which might indicate the variation of the production mechanism within this energy interval.

  6. Photonuclear and Radiation Effects Testing with a Refurbished 20 MeV Medical Electron Linac

    CERN Document Server

    Webb, Timothy; Beezhold, Wendland; De Veaux, Linda C; Harmon, Frank; Petrisko, Jill E; Spaulding, Randy

    2005-01-01

    An S-band 20 MeV electron linear accelerator formerly used for medical applications has been recommissioned to provide a wide range of photonuclear activation studies as well as various radiation effects on biological and microelectronic systems. Four radiation effect applications involving the electron/photon beams are described. Photonuclear activation of a stable isotope of oxygen provides an active means of characterizing polymer degradation. Biological irradiations of microorganisms including bacteria were used to study total dose and dose rate effects on survivability and the adaptation of these organisms to repeated exposures. Microelectronic devices including bipolar junction transistors (BJTs) and diodes were irradiated to study photocurrent from these devices as a function of peak dose rate with comparisons to computer modeling results. In addition, the 20 MeV linac may easily be converted to a medium energy neutron source which has been used to study neutron damage effects on transistors.

  7. Environmental site description for a Uranium Atomic Vapor Laser Isotope Separation (U-AVLIS) production plant at the Paducah Gaseous Diffusion Plant site

    Energy Technology Data Exchange (ETDEWEB)

    Marmer, G.J.; Dunn, C.P.; Moeller, K.L.; Pfingston, J.M.; Policastro, A.J.; Yuen, C.R.; Cleland, J.H. (ed.)

    1991-09-01

    Uranium enrichment in the United States has utilized a diffusion process to preferentially enrich the U-235 isotope in the uranium product. The U-AVLIS process is based on electrostatic extraction of photoionized U-235 atoms from an atomic vapor stream created by electron-beam vaporization of uranium metal alloy. The U-235 atoms are ionized when precisely tuned laser light -- of appropriate power, spectral, and temporal characteristics -- illuminates the uranium vapor and selectively photoionizes the U-235 isotope. A programmatic document for use in screening DOE site to locate a U-AVLIS production plant was developed and implemented in two parts. The first part consisted of a series of screening analyses, based on exclusionary and other criteria, that identified a reasonable number of candidate sites. These sites were subjected to a more rigorous and detailed comparative analysis for the purpose of developing a short list of reasonable alternative sites for later environmental examination. This environmental site description (ESD) provides a detailed description of the PGDP site and vicinity suitable for use in an environmental impact statement (EIS). The report is based on existing literature, data collected at the site, and information collected by Argonne National Laboratory (ANL) staff during a site visit. 65 refs., 15 tabs.

  8. Late production of hydrocarbon gases in sedimentary basins: kinetic and isotopic study; Genese tardive des gaz hydrocarbures dans les bassins sedimentaires: etude cinetique et isotopique

    Energy Technology Data Exchange (ETDEWEB)

    Lorant, F.

    1999-06-23

    the mechanisms of cracking and the isotopic processes. Following this concept, a general class-compound model for the production and the degradation of oil and gas, including the calculation of the isotopic compositions, was set up. The kinetic scheme, based on that proposed by Behar et at. (1992), comprises 10 first-order reactions whose pre exponential factors (A) are not all the same. The various kinetic and isotopic parameters were determined on the basis of pyrolysis experiments performed on an immature Type II kerogen. The first simulations at low temperature show that this model can reproduce isotopic trends that are consistent with natural observations. However the current uncertainty on the isotopic parameters does not yet allow a confident utilization of the model to predict the {delta}{sup 13}C of hydrocarbon gases is the geological conditions. (author)

  9. The use of the stable isotope, oxygen-18, as a tracer to measure gross primary production in coastal and oligotrophic waters and in monoclonal cultures of marine phytoplankton

    Energy Technology Data Exchange (ETDEWEB)

    Grande, K.D.

    1988-01-01

    A new technique was developed to measure the in vitro rates of gross oxygen production in planktonic communities, in which water is enriched with the stable isotope {sup 18}O, and photosynthetic evolution of {sup 18}O{sup 16}O is measured. In order to calculate gross oxygen production, they correct for the {sup 18}O fractionation due to respiration. The standard technique for measuring production in the oceans, {sup 14}C-bicarbonate uptake, has recently been questioned due to discrepancies with other estimates of water column production and suspected intrinsic problems with the {sup 14}C technique. They compared rates of {sup 18}O gross production and {sup 14}C production in oligotrophic and coastal sites. Samples were generally incubated under natural lighting with neutral density screening. Some oligotrophic bottles were incubated in situ at the depth of collection. Rates of {sup 14}C production were 60-100% of {sup 18}O gross production in both coastal and oceanic communities. Assuming a PQ of 1.0 to 1.5, these comparisons suggest that {sup 14}C production rates are not seriously underestimating actual in vitro rates of production. They also measured rates of light respiration in cultures and natural populations by the {sup 18}O technique. The rates of light respiration in algal cultures were generally greater than dark rates by a factor of two to ten. The increased respiration in the light could be due to increased rates of mitochondrial respiration, photorespiration or Mehler respiration. They measured the enhanced {sup 14}C production under reduced (O{sub 2}) conditions (the Warburg effect), as an estimate of the rate of photorespiration. In three clones, rates of photorespiration were a significant fraction of light respiration. In five other clones examined, photorespiration was not implicated as a source of light respiration.

  10. Evaluating nitrogen oxide sources and oxidation pathways impacting aerosol production on the Southern Ute Indian Reservation and Navajo Nation using geochemical isotopic analysis

    Science.gov (United States)

    King, Michael Z.

    Increased emissions of nitrogen oxides (NOx = NO + NO 2) as a result of the development of oil, gas and coal resources in the Four Corners region of the United States have caused concern for area American Indian tribes that levels of ozone, acid rain, and aerosols or particulate matter (PM) may increase on reservation lands. NOx in the atmosphere plays an important role in the formation of these pollutants and high levels are indicators of poor air quality and exposure to them has been linked to a host of human health effects and environmental problems facing today's society. Nitrogen oxides are eventually oxidized in the atmosphere to form nitrate and nitric acid which falls to earth's surface by way of dry or wet deposition. In the end, it is the removal of NOx from the atmosphere by chemical conversion to nitrate that halts this production of oxidants, acids, and aerosols. Despite the importance of understanding atmospheric nitrate (NO3- = HNO3-(g), NO3-(aq), NO3-(s)) production there remains major deficiencies in estimating the significant key reactions that transform NOx into atmospheric nitrate. Stable isotope techniques have shown that variations in oxygen (16O, 17O, 18O) and nitrogen (14N, 15N) isotope abundances in atmospheric nitrate provide significant insight to the sources and oxidation pathways that transform NOx. Therefore, this project applied this resolution using high pressure liquid chromatography and isotope ratio mass spectrometry to determine the chemical and isotopic composition of particulate nitrate (PM2.5 and PM10), collected on the Southern Ute Indian Reservation and Navajo Nation. It was determined that the observed particulate nitrate concentrations on tribal lands were likely linked to seasonal changes in boundary layer height (BLH), local sources, meteorology, photochemistry and increases in windblown crustal material. The Southern Ute Indian Reservation indicated higher delta15N values in comparison to the Navajo Nation study site

  11. Production of very neutron-deficient isotopes near sup 1 sup 0 sup 0 Sn via reactions involving light-particle and cluster emission

    CERN Document Server

    La Commara, M; D'Onofrio, A; Gadea, A; Glogowski, M; Jarillo-Herrero, P; Belcari, N; Borcea, R; De Angelis, G; Fahlander, C; aGórska, M; Grawe, H; Hellström, M; Kirchner, R; Rejmund, M; Roca, V; Roeckl, E; Romano, M; Rykaczewski, K; Schmidt, K; Terrasi, F

    2000-01-01

    The production of very neutron-deficient isotopes near sup 1 sup 0 sup 0 Sn has been investigated by using on-line mass separation of evaporation residues produced by heavy-ion induced complete-fusion reactions. We measured the cross sections for sup 9 sup 9 Cd, sup 1 sup 0 sup 0 In, sup 1 sup 0 sup 1 Sn and sup 1 sup 0 sup 2 In via sup 5 sup 8 Ni+ sup 5 sup 8 Ni fusion reactions followed by cluster emission, and via sup 5 sup 8 Ni+ sup 5 sup 0 Cr fusion reactions accompanied by evaporation of protons, neutrons or alpha particles. Both types of reactions yield similar cross sections for the production of exotic nuclei near sup 1 sup 0 sup 0 Sn. The data are discussed in comparison with results obtained from statistical-model calculations.

  12. Seasonal net and gross biological oxygen production in a temperate shelf sea from oxygen-argon-ratio and oxygen triple isotopes.

    Science.gov (United States)

    Seguro, Isabel; Marca, Alina; Kaiser, Jan

    2017-04-01

    Temperate shelf seas are major carbon sink areas. Quantifying accurately primary production is therefore essential to understand the shelf sea carbon pump and its role in the uptake of anthropogenic CO2 emissions. Here we use high-resolution dissolved oxygen-to-argon (O2/Ar) ratios and oxygen triple isotopes (16O, 17O and 18O) to derive estimates of net and gross biological oxygen production in the Celtic Sea during the most productive seasons (spring, summer and autumn) in 2014-2015. O2/Ar ratios were measured continuously using a shipboard membrane inlet mass spectrometer (MIMS). Additional discrete water samples obtained from CTD hydrocasts were used to measure O2/Ar depth profiles and the δ(17O) and δ(18O) values of dissolved O2. Calculations of net (N(O2/Ar)) and gross (G(17O)) oxygen fluxes showed higher values during the spring bloom and lowest during the autumn bloom. Continuous N(O2/Ar) underway measurement was on average (58±38) mmol m-2 d-1 and discrete G(17O) measurements was average (170±161) mmol m-2 d-1 during the spring bloom. Results from the summer cruise showed a peak in production just below the mixed layer. These peaks are not detectable by high coverage ocean colour satellite systems, typically used to calculate total annual production. Our results show primary production values at unprecedentedly high resolution in the shelf sea.

  13. Production of nuclear sources and nuclear batteries by proton irradiation

    CERN Document Server

    Möller, S

    2016-01-01

    The decay of instable nuclei is being used in a broad range of applications from detector calibration to power sources. As the public acceptance of classical fission nuclear technology is decaying and its integral costs are enormous, alternative production routes are required. The mathematical formalism and fundamental considerations are presented for the use of ion accelerators for isotope production. A focus is put on the production of nuclear power sources to substitute Pu-238 based batteries. 20 MeV protons are found to produce {\\alpha} emitting polonium isotopes from bismuth with an energy efficiency of up to 0.031%. Some hours are required to produce a 1Wth power source of the 2.9 year half-life {\\alpha} emitter Po-208 with a suitable accelerator. The accelerator approach offers more flexibility for tailoring of nuclear products and less waste. The technical requirements are close to and compatible with the planned International Fusion Materials Irradiation Facility accelerator

  14. α-clustering effects in dissipative 12C + 12C reactions at 95 MeV

    Science.gov (United States)

    Baiocco, G.; Morelli, L.; Gulminelli, F.; D'Agostino, M.; Bruno, M.; Abbondanno, U.; Barlini, S.; Bini, M.; Carboni, S.; Casini, G.; Cinausero, M.; Degerlier, M.; Gramegna, F.; Kravchuk, V. L.; Marchi, T.; Olmi, A.; Pasquali, G.; Piantelli, S.; Raduta, Ad. R.

    2013-05-01

    Dissipative 12C+12C reactions at 95 MeV are fully detected in charge with the GARFIELD and RCo apparatuses at Laboratori Nazionali di Legnaro. A comparison to a dedicated Hauser-Feshbach calculation allows us to select events which correspond, to a large extent, to the statistical evaporation of highly excited 24Mg, as well as to extract information on the isotopic distribution of the evaporation residues in coincidence with their complete evaporation chain. Residual deviations from statistical behavior are observed in α yields and attributed to the persistence of cluster correlations well above the 24Mg threshold for six-α decay.

  15. Cross section measurement for (n,n{alpha}) reactions by 14 MeV neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Kasugai, Y.; Ikeda, Y.; Uno, Y. [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment; Yamamoto, H.; Kawade, K.

    1997-03-01

    Nine (n,n{alpha}) cross sections for (n,n{alpha}) reactions induced by 13.5-14.9 MeV neutrons were measured for {sup 51}V, {sup 65}Cu, {sup 71}Ga, {sup 76}Ge, {sup 87}Rb, {sup 91}Zr, {sup 93}Nb, {sup 96}Zr and {sup 109}Ag isotopes by using Fusion Neutronics Source (FNS) at JAERI. The reactions for 91Zr and 96Zr were measured for the first time. The evaluated data of JENDL-3 and ENDF/B-VI were compared with the present data. Some of the evaluated values are much different from our data by a factor more than ten. (author)

  16. \\alpha-clustering effects in dissipative 12C+12C reactions at 95 MeV

    CERN Document Server

    Baiocco, G; Gulminelli, F; D'Agostino, M; Bruno, M; Abbondanno, U; Barlini, S; Bini, M; Carboni, S; Casini, G; Cinausero, M; Gramegna, M Degerlier F; Kravchuk, V L; Marchi, T; Olmi, A; Pasquali, G; Piantelli, S; Raduta, Ad R

    2013-01-01

    Dissipative 12C+12C reactions at 95 MeV are fully detected in charge with the GARFIELD and RCo apparatuses at LNL. A comparison to a dedicated Hauser-Feshbach calculation allows to select events which correspond, to a large extent, to the statistical evaporation of highly excited 24Mg, as well as to extract information on the isotopic distribution of the evaporation residues in coincidence with their complete evaporation chain. Residual deviations from a statistical behaviour are observed in \\alpha yields and attributed to the persistence of cluster correlations well above the 24Mg threshold for 6 \\alpha's decay.

  17. Neutron-induced fission cross sections of 242Pu from 0.3 MeV to 3 MeV

    Science.gov (United States)

    Salvador-Castiñeira, P.; Bryś, T.; Eykens, R.; Hambsch, F.-J.; Göök, A.; Moens, A.; Oberstedt, S.; Sibbens, G.; Vanleeuw, D.; Vidali, M.; Pretel, C.

    2015-10-01

    The majority of the next generation of nuclear power plants (GEN-IV) will work in the fast-neutron-energy region, as opposed to present day thermal reactors. This leads to new and more accurate nuclear-data needs for some minor actinides and structural materials. Following those upcoming demands, the Organisation for Economic Cooperation and Development Nuclear Energy Agency performed a sensitivity study. Based on the latter, an improvement in accuracy from the present 20% to 5% is required for the 242Pu(n ,f ) cross section. Within the same project both the 240Pu(n ,f ) cross section and the 242Pu(n ,f ) cross section were measured at the Van de Graaff accelerator of the Joint Research Centre at the Institute for Reference Materials and Measurements, where quasimonoenergetic neutrons were produced in an energy range from 0.3 MeV up to 3 MeV. A twin Frisch-grid ionization chamber has been used in a back-to-back configuration as fission-fragment detector. The 242Pu(n ,f ) cross section has been normalized to three different isotopes: 237Np(n ,f ) , 235U(n ,f ) , and 238U(n ,f ) . A comprehensive study of the corrections applied to the data and the uncertainties associated is given. The results obtained are in agreement with previous experimental data at the threshold region up to 0.8 MeV. The resonance-like structure at 0.8 to 1.1 MeV, visible in the evaluations and in most previous experimental values, was not reproduced with the same intensity in this experiment. For neutron energies higher than 1.1 MeV, the results of this experiment are slightly lower than the Evaluated Nuclear Data File/B-VII.1 evaluation but in agreement with the experiment of Tovesson et al. (2009) as well as Staples and Morley (1998). Finally, for energies above 1.5 MeV, the results show consistency with the present evaluations.

  18. Optimization of production yields, radionuclidic purity and hotcell shielding of SPECT and PET radionuclides produced by proton irradiation in variable energy 30 MeV cyclotrons--Part 67Ga.

    Science.gov (United States)

    Adam-Rebeles, R; Van den Winkel, P; De Vis, L

    2007-09-01

    Optimization of the production parameters (incident and exit proton energy, thickness of the (68)Zn target layer, decay time to start chemical processing of an irradiated target after the end of bombardment) and of the thickness of the lead shield of the processing hotcell for the cyclotron production of (67)Ga by the (68)Zn(p,2n) threshold reaction are accomplished by powerful divide et impera and binary search algorithms with the Pharmacopoeia radionuclidic purity of the (67)Ga-citrate radiopharmaceutical at a reference time and the locally accepted dose rate level for the controlled area as boundary conditions. Two sets of equations are presented (one associated with the maximum production rate, the other with the use of a minimum target layer thickness) that allow the expression of the optimized production parameters, the radionuclide yields satisfying the Pharmacopoeia requirements at the start of distribution and the necessary shielding as a function of the required activity at the start of distribution and of the maximum allowable beam current on target.

  19. Isotopic Dependence of the Caloric Curve

    CERN Document Server

    Trautmann, W; Aumann, T; Bacri, C O; Barczyk, T; Bassini, R; Bianchin, S; Boiano, C; Botvina, A S; Boudard, A; Brzychczyk, J; Chbihi, A; Cibor, J; Czech, B; De Napoli, M; Ducret, J -E; Emling, H; Frankland, J D; Hellström, M; Henzlova, D; Imme, G; Iori, I; Johansson, H; Kezzar, K; Lafriakh, A; Le Fèvre, A; Gentil, E Le; Leifels, Y; Lühning, J; Lukasik, J; Lynch, W G; Lynen, U; Majka, Z; Mocko, M; Müller, W F J; Mykulyak, A; Orth, H; Otte, A N; Palit, R; Pawlowski, P; Pullia, A; Raciti, G; Rapisarda, E; Sann, H; Schwarz, C; Sfienti, C; Simon, H; Sümmerer, K; Tsang, M B; Verde, G; Volant, C; Wallace, M; Weick, H; Wiechula, J; Wieloch, A; Zwieglinski, B; 10.1016/j.ppnp.2008.12.006

    2009-01-01

    Isotopic effects in projectile fragmentation at relativistic energies have been studied with the ALADIN forward spectrometer at SIS. Stable and radioactive Sn and La beams with an incident energy of 600 MeV per nucleon have been used in order to explore a wide range of isotopic compositions. Chemical freeze-out temperatures are found to be nearly invariant with respect to the A/Z ratio of the produced spectator sources, consistent with predictions for expanded systems. Consequences for the proposed interpretation of chemical breakup temperatures as representing the limiting temperatures predicted by microscopic models are discussed.

  20. Tailoring medium energy proton beam to induce low energy nuclear reactions in ⁸⁶SrCl₂ for production of PET radioisotope ⁸⁶Y.

    Science.gov (United States)

    Medvedev, Dmitri G; Mausner, Leonard F; Pile, Philip

    2015-07-01

    This paper reports results of experiments at Brookhaven Linac Isotope Producer (BLIP) aiming to investigate effective production of positron emitting radioisotope (86)Y by the low energy (86)Sr(p,n) reaction. BLIP is a facility at Brookhaven National Laboratory designed for the proton irradiation of the targets for isotope production at high and intermediate proton energies. The proton beam is delivered by the Linear Accelerator (LINAC) whose incident energy is tunable from 200 to 66 MeV in approximately 21 MeV increments. The array was designed to ensure energy degradation from 66 MeV down to less than 20 MeV. Aluminum slabs were used to degrade the proton energy down to the required range. The production yield of (86)Y (1.2+/-0.1 mCi (44.4+/-3.7) MBq/μAh) and ratio of radioisotopic impurities was determined by assaying an aliquot of the irradiated (86)SrCl2 solution by gamma spectroscopy. The analysis of energy dependence of the (86)Y production yield and the ratios of radioisotopic impurities has been used to adjust degrader thickness. Experimental data showed substantial discrepancies in actual energy propagation compared to energy loss calculations. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Measurement of (n,Xn) reaction cross sections at 96 MeV; Measure des sections efficaces (n,Xn) a 96 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Sagrado Garcia, Melle Inmaculada C. [Ecole Doctorale: SINEM, U.F.R. de Sciences, Universite de Caen/Basse-Normandie, Esplanade Paix14000 Caen (France)

    2006-10-15

    Nucleon induced reactions in the 20-200 MeV energy range are intensively studied since a long time. The evaporation and the pre-equilibrium processes correspond to an important contribution of the production cross section in these reactions. Several theoretical approaches have been proposed and their predictions must be tested. The experimental results shown in this work are the only complete set of data for the (n,Xn) reactions in this energy range. Neutron double differential cross section measurements using lead and iron targets for an incident neutron beam at 96 MeV were carried out at TSL Laboratory in Uppsala, Sweden. The measurements have been performed for the first time with an energy threshold of 2 MeV and for a wide angular range (15 angle - 98 angle). Neutrons have been detected using two independent setups, DECOI and DEMON and CLODIA and SCANDAL, in order to cover the whole energy range (2-100) MeV. The angular distributions, the differential cross sections and the total inelastic production cross sections have been calculated using the double differential cross sections. The comparison between the experimental data and the predictions given by two of the most popular simulation codes, GEANT3 and MCNPX, have been performed, as well as the comparison with the predictions of the microscopic simulation model DYWAN, selected for its treatment of nucleon-nucleon reactions. (author)

  2. Limitations of 14 MeV neutron simulation techniques

    Science.gov (United States)

    Kley, W.; Bishop, G. R.; Sinha, A.

    1988-07-01

    A D-T fusion cycle produces five times more neutrons per unit of energy released than a fission cycle, with about twice the damage energy and the capability to produce ten times more hydrogen, helium and transmutation products than fission neutrons. They determine, together with other parameters, the lifetime of the construction materials for the low plasma-density fusion reactors (tokamak, tandem-mirror, etc.), which require a first wall. For the economie feasibility of fusion power reactors the first wall and blanket materials must withstand a dose approaching 300 to 400 dpa. Arguments are presented that demonstrate that today's simulation techniques using existing fission reactors and charged particle beams are excellent tools to study the underlying basic physical phenomena of the evolving damage structures but are not sufficient to provide a valid technological data base for the design of economie fusion power reactors. It is shown than an optimized spallation neutron source based on a continuous beam of 600 MeV, 6 mA protons is suitable to simulate first wall conditions. Comparing it with FMIT the 35 MeV, 100 mA D + -Li neutron source, we arrive at the following figure of merit: FM = {(dpa·volume) EURAC}/{(dpa·volume) FMIT} = {} = 111 reflecting the fact that the proton beam generates about 100 times more neutrons than the deuteron beam in FMIT for the same beam power.

  3. Production of Medical Radioisotopes in the ORNL High Flux Isotope Reactor (HFIR) for Cancer Treatment and Arterial Restenosis Therapy after PTCA

    Science.gov (United States)

    Knapp, F. F. Jr.; Beets, A. L.; Mirzadeh, S.; Alexander, C. W.; Hobbs, R. L.

    1998-06-01

    The High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory (ORNL) represents an important resource for the production of a wide variety of medical radioisotopes. In addition to serving as a key production site for californium-252 and other transuranic elements, important examples of therapeutic radioisotopes which are currently routinely produced in the HFIR for distribution include dysprosium-166 (parent of holmium-166), rhenium-186, tin-117m and tungsten-188 (parent of rhenium-188). The nine hydraulic tube (HT) positions in the central high flux region permit the insertion and removal of targets at any time during the operating cycle and have traditionally represented a major site for production of medical radioisotopes. To increase the irradiation capabilities of the HFIR, special target holders have recently been designed and fabricated which will be installed in the six Peripheral Target Positions (PTP), which are also located in the high flux region. These positions are only accessible during reactor refueling and will be used for long-term irradiations, such as required for the production of tin-117m and tungsten-188. Each of the PTP tubes will be capable of housing a maximum of eight HT targets, thus increasing the total maximum number of HT targets from the current nine, to a total of 57. In this paper the therapeutic use of reactor-produced radioisotopes for bone pain palliation and vascular brachytherapy and the therapeutic medical radioisotope production capabilities of the ORNL HFIR are briefly discussed.

  4. Production of medical radioisotopes in the ORNL High Flux Isotope Reactor (HFIR) for cancer treatment and arterial restenosis therapy after PTCA

    Energy Technology Data Exchange (ETDEWEB)

    Knapp, F.F. Jr.; Beets, A.L.; Mirzadeh, S.; Alexander, C.W.; Hobbs, R.L.

    1998-06-01

    The High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory (ORNL) represents an important resource for the production of a wide variety of medical radioisotopes. In addition to serving as a key production site for californium-252 and other transuranic elements, important examples of therapeutic radioisotopes which are currently routinely produced in the HFIR for distribution include dysprosium-166 (parent of holmium-166), rhenium-186, tin-117m and tungsten-188 (parent of rhenium-188). The nine hydraulic tube (HT) positions in the central high flux region permit the insertion and removal of targets at any time during the operating cycle and have traditionally represented a major site for production of medical radioisotopes. To increase the irradiation capabilities of the HFIR, special target holders have recently been designed and fabricated which will be installed in the six Peripheral Target Positions (PTP), which are also located in the high flux region. These positions are only accessible during reactor refueling and will be used for long-term irradiations, such as required for the production of tin-117m and tungsten-188. Each of the PTP tubes will be capable of housing a maximum of eight HT targets, thus increasing the total maximum number of HT targets from the current nine, to a total of 57. In this paper the therapeutic use of reactor-produced radioisotopes for bone pain palliation and vascular brachytherapy and the therapeutic medical radioisotope production capabilities of the ORNL HFIR are briefly discussed.

  5. Sci—Fri PM: Topics — 07: Monte Carlo Simulation of Primary Dose and PET Isotope Production for the TRIUMF Proton Therapy Facility

    Energy Technology Data Exchange (ETDEWEB)

    Lindsay, C; Jirasek, A [University of Victoria (Australia); Blackmore, E; Hoehr, C; Schaffer, P; Trinczek, M [TRIUMF (Canada); Sossi, V [University of British Columbia (Canada)

    2014-08-15

    Uveal melanoma is a rare and deadly tumour of the eye with primary metastases in the liver resulting in an 8% 2-year survival rate upon detection. Large growths, or those in close proximity to the optic nerve, pose a particular challenge to the commonly employed eye-sparing technique of eye-plaque brachytherapy. In these cases external beam charged particle therapy offers improved odds in avoiding catastrophic side effects such as neuropathy or blindness. Since 1995, the British Columbia Cancer Agency in partnership with the TRIUMF national laboratory have offered proton therapy in the treatment of difficult ocular tumors. Having seen 175 patients, yielding 80% globe preservation and 82% metastasis free survival as of 2010, this modality has proven to be highly effective. Despite this success, there have been few studies into the use of the world's largest cyclotron in patient care. Here we describe first efforts of modeling the TRIUMF dose delivery system using the FLUKA Monte Carlo package. Details on geometry, estimating beam parameters, measurement of primary dose and simulation of PET isotope production are discussed. Proton depth dose in both modulated and pristine beams is successfully simulated to sub-millimeter precision in range (within limits of measurement) and 2% agreement to measurement within in a treatment volume. With the goal of using PET signals for in vivo dosimetry (alignment), a first look at PET isotope depth distribution is presented — comparing favourably to a naive method of approximating simulated PET slice activity in a Lucite phantom.

  6. Activation cross section measurement at neutron energy from 13.3 to 14.9 MeV using FNS facility

    Energy Technology Data Exchange (ETDEWEB)

    Kasugai, Yoshimi; Ikeda, Yujiro; Uno, Yoshitomo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Yamamoto, Hiroshi; Kawade, Kiyoshi [Nagoya Univ. (Japan)

    2001-03-01

    Sixty activation cross sections have been measured in the neutron energy between 13.4 and 14.9 MeV using intense D-T neutrons source (Fusion Neutronics Source, FNS) at JAERI. The following reactions are included in this work: (1) 32 reactions mainly for lanthanide isotopes, (2) 19 reactions for short-lived products (the half-lives are from 1 s to 20 min) and (3) 9 (n, n{alpha}) reactions. The experimental results were compared with the data reported previously and the evaluated data of ENDF/B-VI Rev. 4, JENDL-3.2 and FENDL/A-2.0. The present data for the (n, p) and (n, {alpha}) reactions were compared with the values estimated by using the empirical formulae proposed by our group in order to validate the systematics for the reactions for the lanthanide isotopes. Systematic trend of (n, n{alpha}) reactions were discussed based on the present data. (author)

  7. Leatherback Isotopes

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — SWFSC is currently working on a project identifying global marine isotopes using leatherback turtles (Dermochelys coriacea) as the indicator species. We currently...

  8. Foliar Stable Isotope Dynamics in a Closed-Canopy Tropical Forest: Towards a Better Understanding of Terrestrial Productivity in the Past

    Science.gov (United States)

    Graham, H. V.; Freeman, K. H.; Wing, S.

    2010-12-01

    Tropical forests with closed canopies today represent a large proportion (~40%) of global terrestrial biomass carbon, at least one-third of global soil carbon and 30-50% of terrestrial productivity. However, productivity of terrestrial habitats in the past is difficult to discern from the fossil record and the geologic history of three-dimensional forest structure remains unknown. This study seeks to identify isotopic and biochemical leaf characteristics that both signify a closed canopy forest and are preserved in the geologic record. The most charismatic feature of dense canopy forests is the extreme light gradient from canopy top to base, with as little as 1% of available light reaching the forest floor. Along this gradient, leaves exhibit strong light-dependent physiological responses and these adaptations are recorded in biochemical and anatomical leaf features. Using the canopy crane access system at Bosque San Lorenzo in Panamá we are able to sample leaves in the full diversity of light environments in a lowland, terre firme rainforest. As expected, bulk leaf material and individual plant waxes reveal a well-known pattern of vertical enrichment of carbon isotopes. This is generally attributed either to 13C-depleted carbon dioxide from respiration in the understory or to the increased photosynthetic rate typical of high light leaves. By comparing bulk leaf 13C to air samples captured in the same sampling locations we are able to contrast the effects of light with air 13C composition. Vertical gradients in the deuterium composition of leaf-water are associated with the evapotranspirative pattern of enrichment in high light leaves. We measured the D/H ratios of extracted n-alkanes to see if this relationship extends from leaf water to the geologically recalcitrant leaf wax lipids. The relationship between light environment and δDleaf as influenced by evapotranspiration can be constrained by measurement of the oxygen isotope ratio of α-cellulose, which

  9. Extension of activation cross-section data of deuteron induced nuclear reactions on cadmium up to 50 MeV

    Science.gov (United States)

    Hermanne, A.; Tárkányi, F.; Takács, S.; Ditrói, F.

    2016-10-01

    The excitation functions for 109,110g,111m+g,113m,114m,115mIn, 107,109,115m,115gCd and 105g,106m,110g,111Ag are presented for stacked foil irradiations on natCd targets in the 49-33 MeV deuteron energy domain. Reduced uncertainty is obtained by determining incident particle flux and energy scale relative to re-measured monitor reactions natAl(d,x)22,24Na. The results were compared to our earlier studies on natCd and on enriched 112Cd targets. The merit of the values predicted by the TALYS 1.6 code (resulting from a weighted combination of reaction cross-section data on all stable Cd isotopes as available in the on-line libraries TENDL-2014 and TENDL-2015) is discussed. Influence on optimal production routes for several radionuclides with practical applications (111In, 114mIn, 115Cd, 109,107Cd….) is reviewed.

  10. Isotopic chirality

    Energy Technology Data Exchange (ETDEWEB)

    Floss, H.G. [Univ. of Washington, Seattle, WA (United States)

    1994-12-01

    This paper deals with compounds that are chiral-at least in part, due to isotope substitution-and their use in tracing the steric course of enzyme reaction in vitro and in vivo. There are other applications of isotopically chiral compounds (for example, in analyzing the steric course of nonenzymatic reactions and in probing the conformation of biomolecules) that are important but they will not be discussed in this context.

  11. Isotopic Paleoclimatology

    Science.gov (United States)

    Bowen, R.

    Paleotemperature scales were calculated by H. C. Urey and others in the 1950s to assess past temperatures, and later work using the stable isotopes of oxygen, hydrogen, and carbon employed standards such as Peedee belemnite (PDB) and Standard Mean Ocean Water (SMOW). Subsequently, subjects as diverse as ice volume and paleotemperatures, oceanic ice and sediment cores, Pleistocene/Holocene climatic changes, and isotope chronostratigraphy extending back to the Precambrian were investigated.

  12. Nuclear gamma rays from 720-MeV alpha-induced reactions on Al-27 and Si-28

    Science.gov (United States)

    Lieb, B. J.; Plendl, H. S.; Funsten, H. O.; Stronach, C. E.; Lind, V. G.

    1980-01-01

    Prompt gamma rays from the interaction of 720-MeV alpha particles with Al-27 and Si-28 were detected and analyzed to identify residual nuclei and to determine cross sections for production of specific levels. No gamma-ray transitions were detected from nuclei heavier than the target. From Doppler broadening, the momentum of the residual nuclei was estimated. The results are compared with previous results for 140- and 1600-MeV alphas on Al-27 and approximately 200-MeV positive or negative pions on Al-27 and Si-28 and fitted to a spallation-yield formula.

  13. Oxygen Isotopes in Meteorites

    Science.gov (United States)

    Clayton, R. N.

    2003-12-01

    wavelength range 90-100 nm. The reaction proceeds by a predissociation mechanism, in which the excited electronic state lives long enough to have well-defined vibrational and rotational energy levels. As a consequence, the three isotopic species - C16O, C17O, and C18O - absorb at different wavelengths, corresponding to the isotope shift in vibrational frequencies. Because of their different number densities, the abundant C16O becomes optically thick in the outermost part of the cloud (nearest to the external source of UV radiation), while the rare C17O and C18O remain optically thin, and hence dissociate at a greater rate in the cloud interior. The differences in chemical reactivity between C16O molecules and 17O and 18O atoms may lead to isotopically selective reaction products. This scenario has been suggested to explain meteoritic isotope patterns, as discussed below (Yurimoto and Kuramoto, 2002).Stable isotope abundances in meteoritic material provide an opportunity to evaluate the thoroughness of mixing of isotopes of diverse stellar sources. Molybdenum presents a good test case: it has seven stable isotopes, derived from at least three types of stellar sources, corresponding to the r-process, s-process, and p-process. Presolar silicon carbide grains, extracted from primitive meteorites, contain molybdenum that has been subject to s-process neutron capture in red-giant stars, resulting in large enrichments of isotopes at masses 95, 96, 97, 98, and severe depletions (up to 100%) of isotopes at masses 92 and 94 (p-process) and 100 (r-process) (Nicolussi et al., 1998). Complementary patterns have been found in whole-rock samples of several meteorites, with >1,000-fold smaller amplitude, suggesting the preservation of a small fraction of the initial isotopic heterogeneity ( Yin et al., 2002; Dauphas et al., 2002). Oxygen is another element for which primordial isotopic heterogeneity might be preserved. This is discussed further below.It would be highly desirable to have

  14. Production of {sup 234,235}Np and {sup 236}Pu in bombardment of {sup 236}U with protons in the energy range from 17 to 40 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Aaltonen, J.; Helariutta, K. [Univ. of Helsinki, Lab. of Radiochemistry, Dept. of Chemistry, Univ. of Helsinki (Finland); Gromova, E.A.; Jakovlev, V.A. [V. G. Khlopin Radium Inst., Lab. of Nuclear Reactions and Nuclear Medicine, St. Petersburg (Russian Federation); Trzaska, W.H.; Huikari, J.; Kolhinen, V.S.; Rinta-Antila, S. [Univ. of Jyvaeskylae, Accelerator Lab., Dept. of Physics, Jyvaeskylae (Finland)

    2005-07-01

    The production of {sup 235}Np and {sup 236}Pu by the reactions {sup 236}U(p, 2n){sup 235}Np and {sup 236}U(p, n{beta}{sup -}){sup 236}Pu using the K-130 cyclotron of the University of Jyvaeskylaewas investigated. The cross sections for the reactions were determined. Thick-target yield curves were derived based on the cross sections. The results are discussed and compared with previous data on other reactions leading to the formation of the same end products. The thick-target yield of {sup 235}Np in the {sup 236}U(p, 2n) reaction is about 50 percent higher than the yield obtained in the {sup 238}U(p, 4n) reaction leading to this nuclide at comparable particle energies. The purity of {sup 236}Pu produced in the {sup 236}U(p, n{beta}{sup -}) reaction is more than ten times better than for earlier known as the purest reaction {sup 237}Np(p, 2n + pn{beta}{sup -}){sup 236}Pu. (orig.)

  15. Nuclear data measurements for 40-90 MeV neutrons at TIARA

    Energy Technology Data Exchange (ETDEWEB)

    Baba, M. [Tohoku Univ., Sendai (Japan). Cyclotron and Radioisotope Center

    2000-03-01

    Experimental activities at the {sup 7}Li neutron source of TIARA, Japan Atomic Energy Research Institute, Takasaki Establishment are reviewed briefly. Experiments on (1) double-differential charged particle production cross sections for 40-90 MeV neutrons and protons, and (2) neutron elastic scattering and non-elastic cross sections are described as well as the frame of the research. (author)

  16. Cross-sections for nuclide production in 56Fe target irradiated by 300, 500,750, 1000, 1500, and 2600 MeV protons compared with data on hydrogen target irradiation by 300, 500, 750, 1000, and 1500 MeV/nucleon 56Fe ions

    CERN Document Server

    Titarenko, Yu E; Titarenko, A Yu; Butko, M A; Pavlov, K V; Florya, S N; Tikhonov, R S; Mashnik, S G; Ignatyuk, A V; Titarenko, N N; Gudowsky, W; Tesinsky, M; Persson, C -M L; Abderrahim, H Ait; Kumawat, H; Duarte, H

    2008-01-01

    Cross-sections for radioactive nuclide production in 56Fe(p,x) reactions at 300, 500, 750, 1000, 1500, and 2600 MeV were measured using the ITEP U-10 proton accelerator. In total, 221 independent and cumulative yields of products of half-lives from 6.6 min to 312 days have been obtained via the direct-spectrometry method. The measured data have been compared with the experimental data obtained elsewhere by the direct and inverse kinematics methods and with calculations by 15 codes, namely: MCNPX (INCL, CEM2k, BERTINI, ISABEL), LAHET (BERTINI, ISABEL), CEM03 (.01, .G1, .S1), LAQGSM03 (.01, .G1, >.S1), CASCADE-2004, LAHETO, and BRIEFF. Most of our data are in a good agreement with the inverse kinematics results and disprove the results of some earlier activation measurements that were quite different from the inverse kinematics measurements. The most significant calculation-to-experiment differences are observed in the yields of the A<30 light nuclei, indicating that further improvements in nuclear reaction ...

  17. Production of cosmogenic isotopes 7Be, 10Be, 14C, 22Na, and 36Cl in the atmosphere: Altitudinal profiles of yield functions

    Science.gov (United States)

    Poluianov, S. V.; Kovaltsov, G. A.; Mishev, A. L.; Usoskin, I. G.

    2016-07-01

    New consistent and precise computations of the production of five cosmogenic radioisotopes, 7Be, 10Be, 14C, 22Na, and 36Cl, in the Earth's atmosphere by cosmic rays are presented in the form of tabulated yield functions. For the first time, a detailed set of the altitude profiles of the production functions is provided which makes it possible to apply the results directly as input for atmospheric transport models. Good agreement with most of the earlier published works for columnar and global isotopic production rates is shown. Altitude profiles of the production are important, in particular for such tasks as studies of strong solar particle events in the past, precise reconstructions of solar activity on long-term scale, tracing air mass dynamics using cosmogenic radioisotopes, etc. As an example, computations of the 10Be deposition flux in the polar region are shown for the last decades and also for a period around 780 A.D. and confronted with the actual measurements in Greenland and Antarctic ice cores.

  18. Excitation function of the alpha particle induced nuclear reactions on enriched 116Cd, production of the theranostic isotope 117mSn

    Science.gov (United States)

    Ditrói, F.; Takács, S.; Haba, H.; Komori, Y.; Aikawa, M.; Szűcs, Z.; Saito, M.

    2016-10-01

    117mSn is one of the radioisotopes can be beneficially produced through alpha particle irradiation. The targets were prepared by deposition of 116Cd metal onto high purity 12 μm thick Cu backing. The average deposited thickness was 21.9 μm. The beam energy was thoroughly measured by Time of Flight (TOF) methods and proved to be 51.2 MeV. For the experiment the well-established stacked foil technique was used. In addition to the Cd targets, Ti foils were also inserted into the stacks for energy and intensity monitoring. The Cu backings were also used for monitoring and as recoil catcher of the reaction products from the cadmium layer. The activities of the irradiated foils were measured with HPGe detector for gamma-ray spectrometry and cross section values were determined. As a result excitation functions for the formation of 117mSn, 117m,gIn, 116mIn, 115mIn and 115m,gCd from enriched 116Cd were deduced and compared with the available literature data and with the results of the nuclear reaction model code calculations EMPIRE 3.2 and TALYS 1.8. Yield curves were also deduced for the measured nuclear reactions and compared with the literature.

  19. Excitation function of the alpha particle induced nuclear reactions on enriched $^{116}$Cd, production of the theranostic isotope $^{117m}$Sn

    CERN Document Server

    Ditrói, F; Haba, H; Komori, Y; Aikawa, M; Szűcs, Z; Saito, M

    2016-01-01

    $^{117m}$Sn is one of the radioisotopes can be beneficially produced through alpha particle irradiation. The targets were prepared by deposition of $^{116}$Cd metal onto high purity 12 $\\mu$m thick Cu backing. The average deposited thickness was 21.9 $\\mu$m. The beam energy was thoroughly measured by Time of Flight (TOF) methods and proved to be 51.2 MeV. For the experiment the well-established stacked foil technique was used. In addition to the Cd targets, Ti foils were also inserted into the stacks for energy and intensity monitoring. The Cu backings were also used for monitoring and as recoil catcher of the reaction products from the cadmium layer. The activities of the irradiated foils were measured with HPGe detector for gamma-ray spectrometry and cross section values were determined. As a result excitation functions for the formation of $^{117m}$Sn, $^{117m,g}$In, $^{116m}$In, $^{115m}$In and $^{115m,g}$Cd from enriched $^{116}$Cd were deduced and compared with the available literature data and with the...

  20. Damage kinetics in MeV gold ion - Irradiated crystalline quartz

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, S.M.M. E-mail: ramos@dpm.univ-lyon1.fr; Clerc, C.; Canut, B.; Chaumont, J.; Toulemonde, M.; Bernas, H

    2000-05-02

    Damage creation in crystalline {alpha}-quartz under gold irradiation was studied at 1.0 and 5.5 MeV using the ARAMIS accelerator at CSNSM (Orsay). Although at these energies the total stopping powers are nearly equal (respectively, 4.20 and 4.46 keV nm{sup -1}), the electronic stopping power is only 1.23 keV nm{sup -1} (25% of the total) at 1 MeV while it reaches 2.75 keV nm{sup -1} (62% of the total) at 5.5 MeV. The electronic stopping power threshold for damage creation in {alpha}-quartz is about 1.8 keV/nm . The experiment thus allows us to follow the damage production kinetics due to nuclear collisions (at 1 MeV) versus electronic collisions (at 5.5 MeV). The damage was determined by channeling Rutherford backscattering (RBS-C) using the 2 MV Van de Graaff at DPM (Villeurbanne). Single ion impacts create damage when electronic stopping dominates, while several impacts are necessary to achieve complete damage when nuclear stopping dominates. Differences in damage efficiencies will be discussed.

  1. Environmental site description for a Uranium Atomic Vapor Laser Isotope Separation (U-AVLIS) production plant at the Portsmouth Gaseous Diffusion Plant site

    Energy Technology Data Exchange (ETDEWEB)

    Marmer, G.J.; Dunn, C.P.; Filley, T.H.; Moeller, K.L.; Pfingston, J.M.; Policastro, A.J.; Cleland, J.H.

    1991-09-01

    Uranium enrichment in the United States has utilized a diffusion process to preferentially enrich the U-235 isotope in the uranium product. In the 1970s, the US Department of Energy (DOE) began investigating more efficient and cost-effective enrichment technologies. In January 1990, the Secretary of Energy approved a plan for the demonstration and deployment of the Uranium Atomic Vapor Laser isotope Separation (U-AVLIS) technology with the near-term goal to provide the necessary information to make a deployment decision by November 1992. Initial facility operation is anticipated for 1999. A programmatic document for use in screening DOE sites to locate a U-AVLIS production plant was developed and implemented in two parts. The first part consisted of a series of screening analyses, based on exclusionary and other criteria, that identified a reasonable number of candidate sites. The final evaluation, which included sensitivity studies, identified the Oak Ridge Gaseous Diffusion Plant (ORGDP) site, the Paducah Gaseous Diffusion Plant (PGDP) site, and the Portsmouth Gaseous Diffusion Plant (PORTS) site as having significant advantages over the other sites considered. This environmental site description (ESD) provides a detailed description of the PORTS site and vicinity suitable for use in an environmental impact statement (EIS). This report is based on existing literature, data collected at the site, and information collected by Argonne National Laboratory (ANL) staff during site visits. The organization of the ESD is as follows. Topics addressed in Sec. 2 include a general site description and the disciplines of geology, water resources, biotic resources, air resources, noise, cultural resources, land use. Socioeconomics, and waste management. Identification of any additional data that would be required for an EIS is presented in Sec. 3.

  2. Design of 10 MeV cyclotron accelerator

    Directory of Open Access Journals (Sweden)

    R Solhju

    2015-09-01

    Full Text Available Design and construction of 10MeV cyclotron has been started at Amirkabir University of Technology since 2012. So far, the conceptual and detail engineering design phases have been finalized. The main purpose of this baby cyclotron is to generate proton beam for the production of PET radioisotopes. The cyclotron consists of magnet, cavity, ion source, RF and LLRF system, vacuum system, cooling system, power amplifiers and power supplies system. In this paper, a brief of design principles for all the parts of cyclotron and their final simulation results is presented. It should be noted that these simulations have been performed and optimized by the most accurate softwares such as TOSCA, ANSYS, HFSS, SolidWorks and CST. Also, the manufacturing feasibility of all the parts is performed and their dimensions and parameters are synchronized with manufacturing standards

  3. Constraints on gamma-ray line and continuum emission from the Galactic Center Region at MeV Energies

    Energy Technology Data Exchange (ETDEWEB)

    Diehl, R.; v. Ballmoos, P.; Schoenfelder, V.

    1988-09-25

    MPE Compton Telescope observations of MeV radiation from the direction of the Galactic Center lead to constraints on the central source and on diffuse processes in the Galaxy: The extent of 1.8 MeV line emission from /sup 26/Al suggests an /sup 26/Al production process with pronounced concentration towards the Galactic Center. The absence of other ..gamma..-ray lines constrains nucleosynthesis and cosmic ray excitation parameters in the Galaxy.

  4. Ge(Li) detector gamma-ray spectrometer system for measurement of the spectra and production cross sections of. gamma. -rays produced by 14 MeV neutron nonelastic interaction with nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Shen Ronglin; Shi Xiamin; Wu Yongshun; Xing Jinjiang; Ding Dazhao

    1982-02-01

    A 42 cm/sup 3/ Ge(Li) detector gamma-ray spectrometer system for measuring the spectra and the production cross sections of ..gamma..-rays produced by fast neutron nonelastic interaction with nuclei is described in this paper. The incident neutrons are produced by T(d,n)/sup 4/He reaction in an high tension set with the incident deuteron energy of 200 keV. The time of flight technique is used to discriminate between the scattered neutrons and gamma-rays resulting from nonelastic interaction. The ..cap alpha..-particles are picked up by a Si(Au) surface barrier detector and the ARC timing discriminaters are used in both Si(Au) and Ge(Li) channels. The overall time resolution (FWHM) of this system is 4.1 ns typically for energy selection threshold at 400keV. The block diagram of spectrometer system is described in detail. The complex complete shielding damage of Ge(Li) detector in this fast neutron field is well discussed.

  5. Isotopic Changes During Digestion: Protein

    Science.gov (United States)

    Tuross, N.

    2013-12-01

    Nutrient and hydrological inputs traverse a complicated route of pH, enzymatic and cellular processes in digestion in higher animals. The end products of digestion are the starting products for biosynthesis that are often used to interpret past life-ways. Using an artificial gut system, the isotopic changes (dD, d18O, d13C and d15N) of protein are documented. Three separate protein sources are subjected to the conditions, chemical and enzymatic, found in the stomach and upper small intestine with only a small shift in the oxygen isotopic composition of the proteins observed. Middle to lower small intestine parameters produced both greater isotopic effects and significantly lower molecular weight products. The role of the gastric enterocyte and the likely involvement of the internal milieu of this cell in the isotopic composition of amino acids that are transported to the liver are reported.

  6. Shielding measurements for a 230 MeV proton beam

    Energy Technology Data Exchange (ETDEWEB)

    Siebers, J.V.

    1990-01-01

    Energetic secondary neutrons produced as protons interact with accelerator components and patients dominate the radiation shielding environment for proton radiotherapy facilities. Due to the scarcity of data describing neutron production, attenuation, absorbed dose, and dose equivalent values, these parameters were measured for 230 MeV proton bombardment of stopping length Al, Fe, and Pb targets at emission angles of 0{degree}, 22{degree}, 45{degree}, and 90{degree} in a thick concrete shield. Low pressure tissue-equivalent proportional counters with volumes ranging from 1 cm{sup 3} to 1000 cm{sup 3} were used to obtain microdosimetric spectra from which absorbed dose and radiation quality are deduced. Does equivalent values and attenuation lengths determined at depth in the shield were found to vary sharply with angle, but were found to be independent of target material. Neutron dose and radiation length values are compared with Monte Carlo neutron transport calculations performed using the Los Alamos High Energy Transport Code (LAHET). Calculations used 230 MeV protons incident upon an Fe target in a shielding geometry similar to that used in the experiment. LAHET calculations overestimated measured attenuation values at 0{degree}, 22{degree}, and 45{degree}, yet correctly predicted the attenuation length at 90{degree}. Comparison of the mean radiation quality estimated with the Monte Carlo calculations with measurements suggest that neutron quality factors should be increased by a factor of 1.4. These results are useful for the shielding design of new facilities as well as for testing neutron production and transport calculations.

  7. Conceptual Design Study of 13 MeV Proton Cyclotron

    Directory of Open Access Journals (Sweden)

    Silakhuddin

    2012-04-01

    Full Text Available A study to determine the conceptual design of a 13 MeV proton cyclotron for PET (Positron Emission Tomography facility has been carried out. Based on studies on reactions of PET radioisotopes production, reaction cross-sections and some design references, a design of the proton cyclotron is proposed. The design criteria for the main components are decided using empirical and semitheoretical methods, as well as by referring to data regarding cyclotrons for PET production. The empirical method was carried out by using some data from operational experiences of BATAN cyclotron at Serpong, while the semitheoretical method was carried out by using the commonly used equations of cyclotron basic theory. The general layout of components and the main components, namely the ion source, the RF dees, the magnet, and the extractor are discussed. Based on the calculations and on the data used, the cyclotron is designed as a negative ion acceleration cyclotron with internal ion source. The designated proton energy and beam currents are 13 MeV and 50 µA. Its magnetic field is in the relativistic mode with sectors on the pole. The magnetic field intensity at the extraction radius is 12.745 kG and in the innermost radius is 12.571 kG. The magnetic poles consist of four sectors to make adequate space for components placement such as dees, ion source, extractor and beam probe. The dee angle is 430. The dee operates at 78 MHz on the fourth harmonic. A multifoil extractor is chosen to obtain an efficient operation

  8. Impact of herbaceous understory vegetation to ecosystem water cycle, productivity and infiltration in a semi arid oak woodland assessed by stable oxygen isotopes

    Science.gov (United States)

    Dubbert, Maren; Piayda, Arndt; Silva, Filipe Costa e.; Correia, Alexandra C.; Pereira, Joao S.; Cuntz, Matthias; Werner, Christiane

    2015-04-01

    Water is one of the key factors driving ecosystem productivity, especially in water-limited ecosystems. Thus a separation of these component fluxes is needed to gain a functional understanding on the development of net ecosystem water and carbon fluxes. Oxygen isotope signatures are valuable tracers for such water movements within the ecosystem because of the distinct isotopic compositions of water in the soil and vegetation. Here, a novel approach was used (Dubbert et al., 2013), combining a custom build flow-through gas-exchange branch chamber with a Cavity Ring-Down Spectrometer in a Mediterranean cork-oak woodland where two vegetation layers respond differently to drought: oak-trees (Quercus suber L.) avoid drought due to their access to ground water while herbaceous plants survive the summer as seeds. We used this approach to quantify the impact of the understory herbaceous vegetation on ecosystem carbon and water fluxes throughout the year and disentangle how ET components of the ecosystem relate to carbon dioxide exchange. Partitioning ecosystem ET and NEE into its three sources revealed that understory vegetation contributed markedly to ecosystem ET and gross primary production (GPP; max. 43 and 51%, respectively). It reached similar water-use efficiencies (WUE) as cork-oak trees and significantly contributed to the ecosystem sink-strength in spring and fall. The understory vegetation layer further strongly inhibited soil evaporation (E) and, although E was large during wet periods, it did not diminish ecosystem WUE during water-limited times (Dubbert et al., 2014a). Although, during most of the year, interactions with trees neither facilitated nor hampered the development of the understory vegetation, strong competition for water could be observed at the end of the growing period, which shortened the life-cycle of understory plants and significantly reduced the carbon uptake of the ecosystem in spring (Dubbert et al., 2014b). Finally, herbaceous understory

  9. Production of medical radioisotopes in the ORNL high flux isotope reactor (HFIR) for cancer treatment and arterial restenosis therapy after PICA

    Science.gov (United States)

    Knapp, F. F.; Beets, A. L.; Mirzadeh, S.; Alexander, C. W.; Hobbs, R. L.

    1999-01-01

    The High Flux Isotope Reactor ( HFIR) at the Oak Ridge National Laboratory ( ORNL) represents an important resource for the production of a wide variety of medical radioisotopes. First beginning operation in 1965, the high thermal neutron flux (2.5×1015 neutrons/cm2/sec at 85 MW) and versatile target irradiation and handling facilities provide the opportunity for production of a wide variety of neutron-rich medical radioisotopes of current interest for therapy. In addition to serving as a key production site for californium-252 and other transuranic elements, important examples of therapeutic radioisotopes which are currently routinely produced in the HFIR for distribution include dysprosium-166 (parent of holmium-166), rhenium-186, tin-117 m and tungsten-188 (parent of rhenium-188). The nine hydraulic tube ( HT) positions in the central high flux region permit the insertion and removal of targets at any time during the operating cycle (22-24 days) and have traditionally represented a major site for production of medical radioisotopes. To increase the irradiation capabilities of the HFIR, special target holders have recently been designed and fabricated which will be installed in the six Peripheral Target Positions ( PTP), which are also located in the high flux region. These positions are only accessible during reactor refueling and will be used for long-term irradiations, such as required for the production of tin-117 m and tungsten-188. Each of the PTP tubes will be capable of housing a maximum of eight HT targets, thus increasing the total maximum number of HT targets from the current nine, to a total of 57. In this paper the therapeutic use of reactor-produced radioisotopes for bone pain palliation and vascular brachytherapy and the therapeutic medical radioisotope production capabilities of the ORNL HFIR are briefly discussed.

  10. Analysis of advanced glycation endproducts in dairy products by isotope dilution liquid chromatography-electrospray tandem mass spectrometry. The particular case of carboxymethyllysine.

    Science.gov (United States)

    Delatour, Thierry; Hegele, Jörg; Parisod, Véronique; Richoz, Janique; Maurer, Sarah; Steven, Matthew; Buetler, Timo

    2009-03-20

    A fully validated multiple-transition recording isotope dilution liquid chromatography-electrospray tandem mass spectrometry (LC-MS/MS) method for the simultaneous quantitative determination of N(epsilon)-carboxymethyllysine (CML) and lysine in dairy products is described. Internal standards were [N-1',2'-(13)C(2)]CML and [1,2,3,4,5,6-(13)C(6)-2,6-(15)N(2)]lysine, and the method was validated by evaluating the selectivity, linearity, precision (repeatability and reproducibility) and trueness, using both powder and liquid products. For liquid dairy products, the repeatability and reproducibility was 2.79% and 11.0%, while 4.85% and 4.92% were determined for powder dairy products, respectively. The trueness of the method ranged from -9.6% to -3.6% for powder and from -0.99% to 6.8% for liquid dairy products. The limit of detection for CML was estimated to be 8 ng CML per mg protein while the limit of quantification was 27 ng CML per mg protein. The method encompasses a proteolytic cleavage mediated by enzymatic digestion to reach a complete release of the amino acids prior to a sample cleanup based on solid phase extraction, and followed by LC-MS/MS analysis of CML and lysine residues. To ensure a suitable performance of the enzymatic digestion, CML measurements were compared to values obtained with an acid hydrolysis-mediated proteolysis. Finally, the method was employed for the analysis of CML in various dairy products. The values compare well to the data available in the literature when similar methods were used, even if some discrepancies were observed upon comparison with the results obtained by other techniques such as enzyme-linked immunosorbent assay and GC-MS.

  11. An isotopic assessment of protein from diet and endogenous stores: Effects on egg production and incubation behaviour of geese

    Science.gov (United States)

    Schmutz, J.A.; Hobson, K.A.; Morse, J.A.

    2006-01-01

    Little empirical information exists to assess to what degree geese use a capital versus income breeding strategy for investing nutrients into eggs. We used stable isotope methods to directly estimate the sources of protein deposited into egg yolks of Brent Branta bernicla and Emperor Geese Anser canagicus on the Yukon-Kuskokwim Delta, Alaska, USA. Approximately 59 and 45% of protein in egg yolks of Brent and Emperor Geese, respectively, was derived from exogenous sources (i.e. food plants on the local breeding area). Within clutches of Brent Goose eggs, first-laid eggs exhibited slightly higher contributions from endogenous reserves than last-laid eggs. This pattern was less clear for Emperor Geese, which may have been a consequence of possibly analyzing eggs that were laid by intraspecific nest parasites rather than by hosts. For both these species, individuals exhibited large variability in the percent contribution of exogenous versus endogenous stores to eggs, and future studies should identify ecological factors related to this variation. Those Emperor Geese in poor body condition incubated their nests less constantly, and based on δ13C values, they fed on terrestrial foods while off their nests. Although not a pure capital breeder, Emperor Geese used nutrients garnered on spring staging areas to fuel virtually all their own maintenance during incubation and to contribute half or more of the nutrients in eggs. These results highlight the ecological importance of these spring staging habitats to geese.

  12. Forensic Stable Isotope Biogeochemistry

    Science.gov (United States)

    Cerling, Thure E.; Barnette, Janet E.; Bowen, Gabriel J.; Chesson, Lesley A.; Ehleringer, James R.; Remien, Christopher H.; Shea, Patrick; Tipple, Brett J.; West, Jason B.

    2016-06-01

    Stable isotopes are being used for forensic science studies, with applications to both natural and manufactured products. In this review we discuss how scientific evidence can be used in the legal context and where the scientific progress of hypothesis revisions can be in tension with the legal expectations of widely used methods for measurements. Although this review is written in the context of US law, many of the considerations of scientific reproducibility and acceptance of relevant scientific data span other legal systems that might apply different legal principles and therefore reach different conclusions. Stable isotopes are used in legal situations for comparing samples for authenticity or evidentiary considerations, in understanding trade patterns of illegal materials, and in understanding the origins of unknown decedents. Isotope evidence is particularly useful when considered in the broad framework of physiochemical processes and in recognizing regional to global patterns found in many materials, including foods and food products, drugs, and humans. Stable isotopes considered in the larger spatial context add an important dimension to forensic science.

  13. Constraining the role of iron in environmental nitrogen transformations. Dual stable isotope systematics of abiotic NO2- reduction by Fe(II) and its production of N2O

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, David [Harvard Univ., Cambridge, MA (United States); Wankel, Scott David [Woods Hole Oceanographic Inst., MA (United States); Buchwald, Carolyn [Woods Hole Oceanographic Inst., MA (United States); Hansel, Colleen [Woods Hole Oceanographic Inst., MA (United States)

    2015-09-16

    Redox reactions involving nitrogen and iron have been shown to have important implications for mobilization of priority contaminants. Thus, an understanding of the linkages between their biogeochemical cycling is critical for predicting subsurface mobilization of radionuclides such as uranium. Despite mounting evidence for biogeochemical interactions between iron and nitrogen, our understanding of their environmental importance remains limited. Here we present an investigation of abiotic nitrite (NO2-) reduction by Fe(II) or ‘chemodenitrification,’ and its relevance to the production of nitrous oxide (N2O), specifically focusing on dual (N and O) isotope systematics under a variety of environmentally relevant conditions. We observe a range of kinetic isotope effects that are regulated by reaction rates, with faster rates at higher pH (~8), higher concentrations of Fe(II) and in the presence of mineral surfaces. A clear non-linear relationship between rate constant and kinetic isotope effects of NO2- reduction was evident (with larger isotope effects at slower rates) and is interpreted as reflecting the dynamics of Fe(II)-N reaction intermediates. N and O isotopic composition of product N2O also suggests a complex network of parallel and/or competing pathways. Our findings suggest that NO2- reduction by Fe(II) may represent an important abiotic source of environmental N2O, especially in iron-rich environments experiencing dynamic redox variations. This study provides a multi-compound, multi-isotope framework for evaluating the environmental occurrence of abiotic NO2- reduction and N2O formation, helping future studies constrain the relative roles of abiotic and biological N2O production pathways.

  14. Measurements of 15.11-MeV gamma-ray flux produced in the reactions C-12(p, p')-C-12*(15.11 MeV) and O-16(p, p' alpha)-C-12*(15.11 MeV)

    Science.gov (United States)

    Lapides, J. R.; Crannell, C. J.; Crannell, H.; Hornyak, W. F.; Seltzer, S. M.; Trombka, J. I.; Wall, N. S.

    1978-01-01

    The flux of 15.11 MeV gamma rays relative to the flux of 4.44 MeV gamma rays which are emitted from the corresponding states of C-12 are a sensitive measure of the spectrum of exciting particles in solar flares and other cosmic sources. Emission of 15.11 MeV gamma rays may result not only from the direct excitation of C-12 but also from the interaction O-16 (p,p' alpha) C-12* sup 15.11 MeV. Although the cross sections for the direct reaction was studied extensively, the cross section for the spallation interaction with O-16 is not reported in the literature. Preliminary measurements demonstrated the feasibility of measuring the production of 15.11 MeV gamma rays by proton interactions with O-16 using the University of Maryland cyclotron facility. For both carbon and oxygen targets the flux of 15.11 MeV gamma rays is being measured relative to the flux of 4.44 MeV gamma rays. The gamma ray emission from de-excitation of the giant dipole resonances is being measured.

  15. Compelling Research Opportunities using Isotopes

    Energy Technology Data Exchange (ETDEWEB)

    None

    2009-04-23

    Isotopes are vital to the science and technology base of the US economy. Isotopes, both stable and radioactive, are essential tools in the growing science, technology, engineering, and health enterprises of the 21st century. The scientific discoveries and associated advances made as a result of the availability of isotopes today span widely from medicine to biology, physics, chemistry, and a broad range of applications in environmental and material sciences. Isotope issues have become crucial aspects of homeland security. Isotopes are utilized in new resource development, in energy from bio-fuels, petrochemical and nuclear fuels, in drug discovery, health care therapies and diagnostics, in nutrition, in agriculture, and in many other areas. The development and production of isotope products unavailable or difficult to get commercially have been most recently the responsibility of the Department of Energy's Nuclear Energy program. The President's FY09 Budget request proposed the transfer of the Isotope Production program to the Department of Energy's Office of Science in Nuclear Physics and to rename it the National Isotope Production and Application program (NIPA). The transfer has now taken place with the signing of the 2009 appropriations bill. In preparation for this, the Nuclear Science Advisory Committee (NSAC) was requested to establish a standing subcommittee, the NSAC Isotope Subcommittee (NSACI), to advise the DOE Office of Nuclear Physics. The request came in the form of two charges: one, on setting research priorities in the short term for the most compelling opportunities from the vast array of disciplines that develop and use isotopes and two, on making a long term strategic plan for the NIPA program. This is the final report to address charge 1. NSACI membership is comprised of experts from the diverse research communities, industry, production, and homeland security. NSACI discussed research opportunities divided into three areas: (1

  16. Cyclotron production of {sup 99m}Tc: Experimental measurement of the {sup 100}Mo(p,x){sup 99}Mo, {sup 99m}Tc and {sup 99g}Tc excitation functions from 8 to 18 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Gagnon, Katherine, E-mail: kgagnon1@ualberta.ca [Edmonton PET Centre, Cross Cancer Institute, University of Alberta, Edmonton, AB (Canada); Benard, Francois [BC Cancer Agency, Vancouver, BC (Canada); Kovacs, Michael [Lawson Health Research Institute, London, ON (Canada); Ruth, Thomas J.; Schaffer, Paul [TRIUMF, Vancouver, BC (Canada); Wilson, John S.; McQuarrie, Steve A. [Edmonton PET Centre, Cross Cancer Institute, University of Alberta, Edmonton, AB (Canada)

    2011-08-15

    Introduction: The cyclotron-based {sup 100}Mo(p,2n){sup 99m}Tc transformation has been proposed as a viable alternative to the reactor based {sup 235}U(n,f){sup 99}Mo{yields}{sup 99m}Tc strategy for production of {sup 99m}Tc. Despite efforts to theoretically model the amount of ground-state {sup 99g}Tc present at end of bombardment for the (p,2n) reaction, experimental validation has yet to be performed. The co-production of {sup 99g}Tc may have important implications in both the subsequent radiopharmaceutical chemistry and patient dosimetry upon injection. Methods: To determine the extent of {sup 99g}Tc co-production, we have experimentally measured the {sup 100}Mo(p,x){sup 99}Mo, {sup 99m}Tc, and {sup 99g}Tc excitation functions in the 8-18 MeV range using a combination of natural abundance and 97.42% enriched {sup 100}Mo foils along with {gamma}-ray spectrometry and ICP-MS. Although the excitation functions for production of {sup 99}Mo and {sup 99m}Tc have been presented previously in the literature, to the best of our knowledge, this work presents the first experimental evaluation of the {sup 100}Mo(p,2n){sup 99g}Tc excitation function. Results: From the experimental cross-section measurements, the {sup 99m}Tc production yields and {sup 99m}Tc/{sup 99m+g}Tc nuclei ratio were calculated for various thick target irradiation conditions. Results suggest that TBq quantities of {sup 99m}Tc can be achieved with a {sup 99m}Tc/{sup 99m+g}Tc nuclei ratio that is on par with the current {sup 99}Mo/{sup 99m}Tc generator standard eluted at a 24-h frequency. Conclusion: These findings suggest that the cyclotron production of {sup 99m}Tc may be a feasible alternative to the current reactor-based production strategy.

  17. 14 MeV neutrons physics and applications

    CERN Document Server

    Valkovic, Vladivoj

    2015-01-01

    Despite the often difficult and time-consuming effort of performing experiments with fast (14 MeV) neutrons, these neutrons can offer special insight into nucleus and other materials because of the absence of charge. 14 MeV Neutrons: Physics and Applications explores fast neutrons in basic science and applications to problems in medicine, the environment, and security.Drawing on his more than 50 years of experience working with 14 MeV neutrons, the author focuses on:Sources of 14 MeV neutrons, including laboratory size accelerators, small and sealed tube generators, well logging sealed tube ac

  18. Characterization of 2 MeV, 4 MeV, 6 MeV and 18 MeV buildup caps for use with a 0.6 cubic centimeter thimble ionization chamber

    Energy Technology Data Exchange (ETDEWEB)

    Salyer, R.L.; VanDenburg, J.W.; Prinja, A.K.; Kirby, T.; Busch, R. [Univ. of New Mexico, Albuquerque, NM (United States); Hong-Nian Jow [Sandia National Laboratories, Albuquerque, NM (United States)

    1996-07-01

    The purpose of this research is to characterize existing 2 MeV, 4 MeV and 6 MeV buildup caps, and to determine if a buildup cap can be made for the 0.6 cm{sup 3} thimble ionization chamber that will accurately measure exposures in a high-energy photon radiation field. Two different radiation transport codes were used to computationally characterize existing 2 MeV, 4 MeV, and 6 MeV buildup caps for a 0.6 cm{sup 3} active volume thimble ionization chamber: ITS, The Integrated TIGER Series of Coupled Electron-Photon Monte Carlo Transport Codes; and CEPXS/ONEDANT, A One-Dimensional Coupled Electron-Photon Discrete Ordinates Code Package. These codes were also used to determine the design characteristics of a buildup cap for use in the 18 MeV photon beam produced by the 14 TW pulsed power HERMES-III electron accelerator. The maximum range of the secondary electron, the depth at which maximum dose occurs, and the point where dose and collision kerma are equal have been determined to establish the validity of electronic equilibrium. The ionization chamber with the appropriate buildup cap was then subjected to a 4 MeV and a 6 MeV bremmstrahlung radiation spectrum to determine the detector response.

  19. Production rate estimation of mycosporine-like amino acids in two Arctic melt ponds by stable isotope probing with NAH(13) CO3.

    Science.gov (United States)

    Ha, Sun-Yong; Min, Jun-Oh; Joo, Hyun Min; Chung, Kyung Ho; Shin, Kyung-Hoon; Yang, EunJin; Kang, Sung-Ho

    2014-10-01

    The net carbon uptake rate and net production rate of mycosporine-like amino acids (MAAs) were measured in phytoplankton from 2 different melt ponds (MPs; closed and open type pond) in the western Arctic Ocean using a (13) C stable isotope tracer technique. The Research Vessel Araon visited ice-covered western-central basins situated at 82°N and 173°E in the summer of 2012, when Arctic sea ice declined to a record minimum. The average net carbon uptake rate of the phytoplankton in polycarbonate (PC) bottles in the closed MP was 3.24 mg C · m(-3) · h(-1) (SD = ±1.12 mg C · m(-3) · h(-1) ), while that in the open MP was 1.3 mg C · m(-3) · h(-1) (SD = ±0.05 mg C · m(-3) · h(-1) ). The net production rate of total MAAs in incubated PC bottles was highest (1.44 (SD = ±0.24) ng C · L(-1) · h(-1) ) in the open MP and lowest (0.05 (SD = ±0.003) ng C · L(-1) · h(-1) ) in the closed MP. The net production rate of shinorine and palythine in incubated PC bottles at the open MP presented significantly high values 0.76 (SD = ±0.12) ng C · L(-1) · h(-1) and 0.53 (SD = ±0.06) ng C · L(-1) · h(-1) . Our results showed that high net production rate of MAAs in the open MP was enhanced by a combination of osmotic and UVR stress and that in situ net production rates of individual MAA can be determined using (13) C tracer in MPs in Arctic sea ice.

  20. Cross section ratio and angular distributions of the reaction p + d → {sup 3}He + η at 48.8 MeV and 59.8 MeV excess energy

    Energy Technology Data Exchange (ETDEWEB)

    Adlarson, P.; Calen, H.; Fransson, K.; Gullstroem, C.O.; Heijkenskjoeld, L.; Hoeistad, B.; Johansson, T.; Marciniewski, P.; Redmer, C.F.; Wolke, M.; Zlomanczuk, J. [Uppsala University, Division of Nuclear Physics, Department of Physics and Astronomy, Box 516, Uppsala (Sweden); Augustyniak, W.; Marianski, B.; Morsch, H.P.; Trzcinski, A.; Zupranski, P. [National Centre for Nuclear Research, Department of Nuclear Physics, Warsaw (Poland); Bardan, W.; Ciepal, I.; Czerwinski, E.; Hodana, M.; Jany, A.; Jany, B.R.; Jarczyk, L.; Kamys, B.; Kistryn, S.; Krzemien, W.; Magiera, A.; Moskal, P.; Ozerianska, I.; Podkopal, P.; Rudy, Z.; Skurzok, M.; Smyrski, J.; Wronska, A.; Zielinski, M.J. [Jagiellonian University, Institute of Physics, Krakow (Poland); Bashkanov, M.; Clement, H.; Doroshkevich, E.; Perez del Rio, E.; Pricking, A.; Skorodko, T.; Wagner, G.J. [Eberhard-Karls-Universitaet Tuebingen, Physikalisches Institut, Tuebingen (Germany); Physikalisches Institut der Universitaet Tuebingen, Kepler Center fuer Astro- und Teilchenphysik, Tuebingen (Germany); Bergmann, F.S.; Demmich, K.; Goslawski, P.; Huesken, N.; Khoukaz, A.; Passfeld, A.; Taeschner, A. [Westfaelische Wilhelms-Universitaet Muenster, Institut fuer Kernphysik, Muenster (Germany); Berlowski, M.; Stepaniak, J. [National Centre for Nuclear Research, High Energy Physics Department, Warsaw (Poland); Bhatt, H.; Lalwani, K.; Varma, R. [Indian Institute of Technology Bombay, Department of Physics, Mumbai, Maharashtra (India); Buescher, M.; Engels, R.; Goldenbaum, F.; Hejny, V.; Khan, F.A.; Lersch, D.; Lorentz, B.; Maier, R.; Ohm, H.; Prasuhn, D.; Schadmand, S.; Sefzick, T.; Stassen, R.; Sterzenbach, G.; Stockhorst, H.; Stroeher, H.; Wurm, P.; Zurek, M. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (Germany); Coderre, D.; Ritman, J. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (Germany); Ruhr-Universitaet Bochum, Institut fuer Experimentalphysik I, Bochum (Germany); Erven, A.; Erven, W.; Kemmerling, G.; Kleines, H.; Wuestner, P. [Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (Germany); Forschungszentrum Juelich, Zentralinstitut fuer Engineering, Elektronik und Analytik, Juelich (Germany); Eyrich, W.; Hauenstein, F.; Krapp, M.; Zink, A. [Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Physikalisches Institut, Erlangen (Germany); Fedorets, P. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (Germany); State Scientific Center of the Russian Federation, Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Foehl, K. [Justus-Liebig-Universitaet Giessen, II. Physikalisches Institut, Giessen (Germany); Goswami, A. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (Germany); Indian Institute of Technology Indore, Department of Physics, Indore, Madhya Pradesh (India); Grigoryev, K. [Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (Germany); RWTH Aachen, III. Physikalisches Institut B, Physikzentrum, Aachen (Germany); Petersburg Nuclear Physics Institute, High Energy Physics Division, Leningrad district (Russian Federation); Kirillov, D.A.; Piskunov, N.M. [Joint Institute for Nuclear Physics, Veksler and Baldin Laboratory of High Energiy Physics, Moscow region (Russian Federation); Klos, B.; Stephan, E.; Weglorz, W. [University of Silesia, August Chelkowski Institute of Physics, Katowice (Poland); Kulessa, P.; Pysz, K.; Siudak, R.; Szczurek, A. [Polish Academy of Sciences, The Henryk Niewodniczanski Institute of Nuclear Physics, Krakow (Poland); Kupsc, A.; Pszczel, D. [Uppsala University, Division of Nuclear Physics, Department of Physics and Astronomy, Box 516, Uppsala (Sweden); National Centre for Nuclear Research, High Energy Physics Department, Warsaw (Poland); Mikirtychiants, M. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (DE); Ruhr-Universitaet Bochum, Institut fuer Experimentalphysik I, Bochum (DE); Petersburg Nuclear Physics Institute, High Energy Physics Division, Leningrad district (RU); Pyszniak, A. [Uppsala University, Division of Nuclear Physics, Department of Physics and Astronomy, Box 516, Uppsala (SE); Jagiellonian University, Institute of Physics, Krakow (PL); Roy, A. [Indian Institute of Technology Indore, Department of Physics, Indore, Madhya Pradesh (IN); Sawant, S. [Indian Institute of Technology Bombay, Department of Physics, Mumbai, Maharashtra (IN); Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (DE); Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (DE); Serdyuk, V. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (DE); Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (DE); Joint Institute for Nuclear Physics, Dzhelepov Laboratory of Nuclear Problems, Moscow region (RU); Sopov, V. [State Scientific Center of the Russian Federation, Institute for Theoretical and Experimental Physics, Moscow (RU); Yamamoto, A. [High Energy Accelerator Research Organization KEK, Tsukuba, Ibaraki (JP); Yurev, L. [Joint Institute for Nuclear Physics, Dzhelepov Laboratory of Nuclear Problems, Moscow region (RU); Zabierowski, J. [National Centre for Nuclear Research, Department of Cosmic Ray Physics, Lodz (PL); Collaboration: WASA-at-COSY Collaboration

    2014-06-15

    We present new data for angular distributions and on the cross section ratio of the p+d → {sup 3}He + η reaction at excess energies of Q = 48.8 MeV and Q = 59.8 MeV. The data have been obtained at the WASA-at-COSY experiment (Forschungszentrum Juelich) using a proton beam and a deuterium pellet target. While the shape of obtained angular distributions show only a slow variation with the energy, the new results indicate a distinct and unexpected total cross section fluctuation between Q = 20 MeV and Q = 60 MeV, which might indicate the variation of the production mechanism within this energy interval. (orig.)