Measurements Of Total Cross Sections And Resonance Parameters Analysis Of Natural Bismoth, Molybdenum

The neutron total cross sections and resonance parameters are important parts of nuclear data, which play significant role in the field of the nuclear theory research and the design of the large nuclear facilities such as reactor, nuclear power plant and so on. Due to the better characteristics of Bismuth and Molybdenum, they have a wide potential use in practice. Although many experimenters have measured the neutron total cross sections of these two samples and analyzed resonance parameters, there exist discrepancies among these data, especially in the resonance region. Therefore, it is a need to measure the neutron total cross sections as well as resonance parameters again. Another purpose of this thesis is to study and establish the method of analysing resonance parameters using SAMMY code in Windows environment.The neutron total cross section data with high precision in broad energy region can be obtained by using time of flight (TOF) method and transmission measurement on the accelerator white neutron source or fast pulse reactor neutron source. The transmission experiment of the natural Bismuth and Molybdenum was accomplished at Pohang Accelerator Laboratory in South Korea. The notch filters composed of Co, In, Cd were used to estimate the background level and calculate the length of neutron flight path. The results of data process and analysis are close to the evaluations data of ENDF/B-VI.8.Resonance parameters of Mo sample from 0.1eV to 200eV energy region were determined by a consistent analysis in which corrections for Doppler broadening, resolution broadening, and other experimental effects were incorporated to the SAMMY code. The process of analysis was shown in detail. The resonance parameters obtained from the SAMMY analysis of the experimental data for the Mo are also close to the ENDF data.