Experimental and theoretical study of the residual nuclide production in 40-2600 MeV proton-irradiated thin targets of ads structure materials

The 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 Project is an extension of the researches carried out earlier under the ISTC Projects #017, #839, and #2002 which provided more 10000 residual nuclide production cross sections mainly in materials intended to use as target materials of the ADS. This Project includes 57 measurement runs carried out using the 97 targets made only of the ADS structural materials of both monoisotopic (56Fe, 93Nb, 181Ta) and natural (natCr, natNi, natW) compositions within minutely fractionated proton energy range, namely, at 0.04, 0.07, 0.1, 0.15, 0.25, 0.4, 0.6, 0.8, 1.2, 1.6 and 2.6GeV. All the targets were irradiated using the ITEP U-10 proton synchrotron. The experimental nuclide yields are determined by the direct γ-spectrometry and α-spectrometry methods. As a result, 3839 cumulative and independent yields of residual β-radioactive product nuclei with lifetimes range from 6 minutes to 10 years as well as 12 cumulative yields of α- radioactive 148Gd whose lifetime is 74.6 years have been measured. Besides, the cross sections for the 27Al(p,x)22Na , 27Al(p,x)24Na and 27Al(p,x)7Be monitor reactions have been measured at the same proton energies with the use of the current transformer technique. The γ-spectrometer resolution is 1.8 keV in the 1332 keV 60Co γ-line. The experimental γ-spectra were processed by the GENIE2000 code. The γ-lines were identified, and the cross sections calculated, by the ITEP-developed SIGMA code using the PCNUDAT database. The proton fluence was monitored by the 27Al(p,x)22Na reaction. Measurement data have been compared with the calculation results of the BERTINI and ISABEL models of MCNPX code, CEM03.02, INCL 4.2, INCL4.5, CASCADE07, and PHITS codes. The predictive power of the tested codes has been found to be different, but still satisfactory throughout the mass and energy ranges of most of the reaction products obtained in the shallow spallation region by all the above-mentioned codes. On the other hand, the predictive power of the codes has proven to be very unsatisfactory for the reaction products within the deep spallation, fission, and fragmentation regions. Therefore, all the codes have to be improved, with their associate models for generation of the fission and fragmentation products being most desirable. (author)