Development Of An Experimental Set-up For ADS Spallation Target Relevant To Nuclear Data Measurements And Benchmarking Of Evaluated Neutron Nuclear Data For Tungsten

Nuclear data are the fundamental data for the nuclear science and engineering applications. Accelerator driven subcritical systems(ADS) spallation target relevant to nuclear data mainly encompass data of various physical nuclear interactions between proton, neutron, and light nuclei with the spallation target system related materials. A large number of physical quantities are included, such as reaction total cross section, scattering cross section, neutron and light nuclei production yield and double differential cross section and angular distribution, charge and mass distribution of the spallation products etc. The studies for nuclear data of the spallation target as an important component part of the ADS have very important meaning.ADS spallation target related nuclear data cover a large number of nuclear data of wide energy range with high accuracy. It’s impossible for carrying out the spallation reaction experimental measurements in the whole energy range. Therefore, the accurate theoretical calculations play very important role in the evaluations of the nuclear data. The several laboratories worldwide have performed spallation reaction related experimental measurements and provide valuable data for the improvement of nuclear models. In this work, the calculated results of spallation reaction nuclear models are compared with the available experimental data. The larger discrepancies are still observed between the calculations with the experiments. However, much more experimental measurements are needed for the validations and verifications of nuclear models.The main research of this thesis focused on the design, construction, and first beam experiment for spallation target of the experimental setup, which was based on Cooling Storage Ring of Heavy Ion Research Facility in Lanzhou(HIRFL-CSR), for measuring the ADS spallation target related nuclear data. The experimental setup was composed of a high vacuum thin metal foil ion beam window, a remote controlled moving target system, detection system(beam pick-up detector, a neutron time of flight spectrometer, light charged particle spectrometer, and gamma detector array), electronic and data acquisition system. The secondary neutron, gamma, and light charged particles from the ADS spallation target key materials Pb, W targets bombarded with 400 Me V/u 16 O ion beam were experimentally measured by using the experimental setup. The energy spectrum, production yield, and angular distribution are accurately obtained by data analysis of experimental data. In order to validate the experimental results, simulations were performed by using the GEANT4 Monte Carlo simulation code and QMD theoretical model. From the comparison results, it’s shown that the experimental apparatus and data analysis procedures work well. At present, the experimental measurement of accelerator driven white neutron energy spectrum in the range of several Me V to hundreds of Me V was done for the first time in China.Tungsten is proposed to be one of the most important materials for designing the fusion reactor, spallation source and ADS project, because of its high melting point(3410 ?C), high heat conductivity, and good neutronic performance. Integral benchmark experiments of evaluated nuclear data for the ADS spallation target candidate material W with 14.8 Me V neutrons have been investigated in this paper. Leakage neutron spectra from the irradiation of D-T neutrons on Tungsten slab sample were experimentally measured at 60? and 120? by using a time-of-flight method coupled BC501 A liquid scintillator neutron detector. Detailed simulations are carried out by MCNP-4C with evaluated nuclear data of the ADS-2.0, ENDF/B-VII.0, ENDF/B-VII.1, JENDL-4.0, and CENDL-3.1 libraries. The accuracy of evaluated nuclear data of Tungsten has been examined by comparing measured leakage neutron spectra with calculated ones. From the results, it is found that the calculations with ADS-2.0 and ENDF/B-VII.1 give good agreements with the experiments. However, the calculated spectra using data from ENDF/B-VII.0,JENDL-4.0, and CENDL-3.1 libraries showed larger discrepancies with the measured ones, especially around 8.5-13.5 Me V. The present work shows that the experimental apparatus and the data analysis procedures work well and provide valuable evaluated nuclear data for Tungsten for the design of ADS spallation target.