Pulsed Neutron Inelastic Scattering And Capture ¦Ã Spectroscopy Experiments

In the foreign country, Neutron Induced Prompt Gamma-ray Analysis桸IPGA was used to analyze the elements in substance and has been used in real production and industry' s analysis on line now. In our country, the method has been studied and used from 70' s and has been more and more perfect. However, the neutron source they used is the isotope source. As the study of experimental methods, we use the pulse neutron generator as the neutron source. Along with the linear gate circuit and multichannel pulse amplitude analyzer, we obtain the inelastic scattering Gamma spectra and capture spectra to analyze the substances.At first, a circuit of time-amplitude converter with a precision of 0. lus has been developed. It' s working principle and fundamental composition are discussed. The pulse neutron generator' s delaying time are measured by the time-amplitude converter and multichannel pulse amplitude analyzer. According to these times, the linear gate circuit' s opening time can be adjusted.A linear gate circuit has been developed. Using it , time amplitude converter and pulse neutron generator, the Y spectra of 14MeV pulse neutrons is measured. Utilizing the time difference of several different reactions about the interaction of neutrons and nucleus, the whole spectra and the capture spectra are measured. A method that uses double gate subtracting background to gain the fast neutrons' inelastic scattering Y spectra is introduced. Utilizing the high and evident characteristic of inelastic scattering Y rays' energy of C and0, the water and polyethycene' s water content are contained. The measurement of water content in materials by neutron generator is studied and the principle of it is introduced. Utilizing the sand as the sample, the sand with different water content is measured by D-D neutron generator and D-T neutron generator and the scaling curves are offered. The simulated curves and formulas are offered. Several groups of sand with unknown water content are measured. Contrasting with the simulated curves' formulas, the errors' range are offered. Using the lead as the displaying element, how the variation of the material' s density affects the counts of the lead area is studied. A method measuring the material' s density and adjusting the water content is introduced.