Yields of Residual Nuclei from Proton-Irradiated Materials
Experimental and Theoretical Study of the Residual Nuclide Production in 40-2600 MeV Proton-Irradiated Thin Targets of ADS Basic Materials
Tech Area / Field
- FUS-HSF/Hybrid Systems and Fuel Cycle/Fusion
- PHY-ANU/Atomic and Nuclear Physics/Physics
3 Approved without Funding
ITEF (ITEP), Russia, Moscow
- CEA / DSM / DAPNIA/CEN Saclay / Service de Physique Nucleaire, France, Gif-sur-Yvette Cedex\nUniversität Hannover / Zentrum für Strahlenschutz und Radioekologie (ZSR), Germany, Hannover\nForschungszentrum Karlsruhe Technik und Umwelt, Germany, Karlsruhe\nJapan Atomic Energy Agency / J-PARC Center, Japan, Ibaraki\nInternational Atomic Energy Agency, Austria, Vienna
Project summaryThe Project is aimed at experimental and theoretical studying the independent and cumulative yields of residual radioactive nuclei produced in high-energy proton-irradiated structure materials intended for constructing the high-power Accelerator-Driven Systems (ADS) with a high-current proton accelerator.
The recent advances in studying of the ADS potentialities permit realization of the pilot ADS facilities, such as SAD (Dubna), TRADE (ENEA), MYRRHA (SCK-CEN), SNS(ORNL), and others. The key point of the respective designs is to select the structural materials for the most important ADS components such as the neutron-producing target, the separating window, the bending magnets, etc. The structural material properties define not only the main technical characteristics of the ADS facilities, but also, in fact, their true reliability. The data to be obtained under the proposed Project will be extremely important when estimating the structural material behavior in high-energy radiation fields. The residual product yields affect strongly the instantaneous and residual radioactivity of materials, their corrosion properties (embrittlement included), evolution of gaseous products, neutron ‘poisoning’ of materials, etc.
The proposed project is an extension of the researches carried out earlier under the following ISTC Projects:
- #017 Feasibility study of the basic technologies for weapon plutonium conversion and for long-lived radioactive waste transmutation (measurements of residual product nuclei in 0.13 and 1.5 GeV proton-irradiated Pb and Bi isotopes);
- #839 Experimental and theoretical study of the yields of residual product nuclei produced in thin targets irradiated by 100-2600 MeV protons (measurements of the yields of residual radioactive product nuclei in such target materials as 182W, 183W, 184W, 186W, natHg, in such structure materials as 93Nb, 56Fe, 59Co, 63Cu, and 65Cu, 58Ni, as well as also in 99Tc, 232Th, in natU, totaling to 47 measurement runs at proton energies of 100, 200, 800, 1200, 1600, and 2600 MeV). Over 4300 yields have been determined under the ISTC Project #839. The results are presented in the Technical Report (http://www-nds.iaea.org/reports/indc-ccp-434.pdf) and have been included in the EXFOR database (files O0781, O0782, O0978-O0987, and O1018-O1021). Some of the results are presented in Nucl. Instr. & Meth, A414, 73-99 (1998);
- #2002 Experimental and theoretical studies of the yields of residual product nuclei produced in 40-2600 MeV proton-irradiated Pb and Bi targets (measurements of radioactive residual product nuclide yields in such basic target materials as 206,207,208,nat.Pb, and 209Bi, totaling to 55 measurements runs at proton energies of 40,70, 100, 150, 250, 400, 600, 800, 1200, 1600, and 2600 MeV). Over 5500 yields have been determined under the ISTC Project #2002. The results are presented in the Technical Report and will be accessible via the EXFOR database. Besides, the determination techniques and some of the results (208Pb at 1 GeV) are presented in Phys. Rev. C65, 064610 (2002);
- #3266 “Experimental and theoretical study of the residual nuclide production in 40-2600 MeV proton-irradiated thin targets of ADS structure materials” (measurements of radioactive residual product nuclide yields in such basic structure materials such as 56Fe, 93Nb, 181Ta, natCr, natNi, natW – in total, 66 experiments at at 40, 70, 100, 150, 250, 400, 600, 800, 1200, 1600, and 2600 MeV (Additionally, 56Fe will be irradiated by 300, 500, 750, 1000 and 1500MeV protons) and 8 experiments at 800, 1200, 1600 and 2600 MeV aimed to measure alpha-active 148Gd yield from 181Ta and natW. Over 4500 yields have been determined under the ISTC Project #3266. The results are presented in the Technical Report and will be accessible via the EXFOR database. Besides, the determination techniques and some of the results (56Fe at by 300, 500, 750, 1000 and 1500MeV) are presented in Phys. Rev. C (2008) in press.
The proposed Project suggests that 88 measurement runs should be carried out using the targets made only of the ADS window and structural materials of both monoisotopic (112Sn, 124Sn, 115In) and natural (natTi, natZr, natMo, natIn, natSn) compositions within minutely fractionated proton energy range, namely, at 40, 70, 100, 150, 250, 400, 600, 800, 1200, 1600, and 2600 MeV. The targets will be irradiated using the ITEP U-10 proton synchrotron. The experiments are aimed at determining the independent and cumulative yields (cross sections for production) of radioactive residual product nuclei in the proton-irradiated samples
The data on the residual product yields from the structural materials are not only of particular importance in the practical applications relevant to the ADS facilities, but also of fundamental importance because they permit verifying and updating the present-day theoretical models of hadron-nucleus interactions. The experimental data to be obtained under the proposed Project will be analyzed using the latest versions of the intranuclear-cascade-model codes: (LAHET, CEM03, LAQGSM+GEM2, INCL4+ABLA, CASCADE), as well as the modified versions of the codes (LAHETO and CASCADO) developed under the previous ISTC Projects #2002 and 3266. The comparison between the measured and simulated yields will make it possible to estimate more accurately the main features of intranuclear processes and, in particular, to clarify the nuclear multi-fragmentation processes at the incident particle energies below 1 GeV and to get important fresh information on cluster emission from high-excited nuclei. The results of comparing between the experimental and calculated results will be presented for all codes to be the plots of excitation functions for each of the measured products and of distributions of the measured and calculated mass yields. This presentation makes the differences between the experimental and calculated data as visual as possible.
The monoisotopism of many targets used in the Project and, hence, the unambiguous identification of the observed reaction channels will turn the data obtained under the proposed Project into an indispensable tool for the authors to further modify their codes, thereby making the codes more reliable and trustworthy when used in the ADS designs. The optimal parameters of the modified versions of CASCADE, CASCADO, and LAHETO will be found basing on the experimental data on the energy dependences of the spallation and fission product yields.
Moreover, the measured data can be used as experimental basis in international intercomparisons of theoretical models and codes as similar as the data obtained under the previous ISTC Projects #2002 and #3266 are being used in the intercomparison being done under the IAEA auspices in 2008-2009.
The irradiation modes information, the measured gamma- and alpha-spectra, and the results of processing the spectra and identifying the product nuclides will be available on a CD attached to the Final Report, pending eventual simulation of the experimental data by other gamma-spectrum processing codes.
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