Benchmarking Of Evaluated Neutron Nuclear Data For Granular Tungsten And Gallium Relevant To ADS Spallation Target

Accelerator driven subcritical systems(ADS) is regarded as a safe, clean and promising nuclear power system, which can be used for the transmutation of nuclear waste and the breeding of nuclear fuel. Also it can effectively improve the utilization of nuclear resources. The design of ADS spallation target requires precise and reliable nuclear data. ADS research team of Chinese Academy of Sciences(CAS) proposed a new concept for a Gravity-driven dense granular flow spallation target. The target material is Tungsten-based alloys solid particles. The neutron nuclear data of granular Tungsten is very important for the design of spallation target. Gallium can be used as a liquid metal coolant. It also has important application in nuclear engineering, national defense, and nuclear astrophysics research. The research work of this paper is important for the improvement of nuclear data, benchmarking neutron evaluated nuclear data and validation of nuclear reaction models. It has also very important application in the design of spallation target.Benchmarking of neutron evaluated nuclear data for granular Tungsten and Gallium was performed at China Institute of Atomic Energy(CIAE). Neutrons of nuclear data benchmarking experimental system were produced by the T(d, n)4He reaction using 300 kV Cockcroft-Walton accelerator. The leakage neutron spectra from Granular Tungsten(container size: 10 cm×10 cm×7.2 cm, granular diameter: 1 mm) and Gallium(size: Φ13 cm ×6.4 cm,Φ13 cm ×3.2 cm) at 60°and 120°were precisely measured by time-of-flight(TOF) technique with a BC501 A scintillation detector. The leakage neutron spectra were calculated by MCNP code with the major four evaluated nuclear data libraries(ENDF/BVII.0, JENDL4.0, CENDL3.1 and JEFF3.1) and compared with the experimental data for the verification of the nuclear data files. The neutron transport behavior in granular Tungsten target was studied in detail.The results of the leakage neutron spectra from granular Tungsten target show that the experimental data are well reproduced by MCNP simulations with the ENDF/BVII.0 and JEFF3.1 libraries. Considering of five different distribution structures(FCC, BCC, CHPOP, SC and Block structure) of granular Tungsten, the neutron transport behavior in granular Tungsten target was studied with MCNP code. The results show that the neutron leakage spectrum mainly depends on the packing fraction of granular Tungsten. The distribution structure of granular Tungsten has very little effect on neutron leakage spectrum at the same packing fraction.For gallium target, the measured spectra can be well reproduced by MCNP calculations with the ENDF/B-VII.0, JENDL-4.0 and CENDL3.1 evaluated nuclear data libraries, except for the inelastic contributions around En =10–13 MeV. All three libraries significantly underestimate the inelastic contributions. The inelastic contributions are further studied using the TALYS code. Considering of three physical processes(direct, pre-equilibrium and compound nucleus reactions), the experimental spectra are reproduced reasonably well in the whole energy range by the TALYS calculation, including the inelastic contributions.In this thesis, TALYS, INCL and GLAUBER model are used for the calculation of proton-induced and neutron-induced reactions related to W and Ga targets. The reliability of models is verified.