Monte Carlo Method In The Neutron Capture Reaction Cross Section Measurements Of The Amendment Application

Neutron capture reaction i.e (n,γ) reaction, it is an important neutron nuclear reaction. Capture reaction cross-section is important data in designed reactors, shielding materials selection and the need of nuclear research. Therefore, the precise measurement of neutron capture reaction cross-section data is of great significance.Samarium is an important fusion reactor containment envelope material. In fusion neutron exposure, Through nuclear reactions (n, γ ),¹⁵²Sm generates its isotope ¹⁵³Sm ,which has a 46.7 hours half life. Thus, maintenance of reactor must consider its impact. In 1keV-lMeV, neutron capture reaction cross-section data of ¹⁵²Sm is scarce, there are a large difference between reported data. In 1993, a expert seminar for nuclear fusion reactor data was convened in theUnited States, and the capture reaction cross-section of ¹⁵²Sm (n,γ)¹⁵³Smreaction was a requirement list. Therefore, we carried out this neutron capture reaction cross-section measurement in 22-1019keV.At Beijing University, experiment was carried out on 4.5MeV electrostatic accelerator. Neutron source were provided through reactions ⁷Li(p,n) ⁷Be and T(p,n) ³He, based on the neutron capture cross-section of ¹⁹⁷Au,We have measured the neutron capture reaction cross section of ¹⁵²Sm.In experimental design and data processing, major errors have been adjusted. However, two errors could not be adjusted, one is the multiple scattering effect which induced by the pipeline material, cooling water and the envelope materials on samples, the other is the self-shielding effect since neutron responses with particles when it penetrates through material. Therefore, we use Monte Carlo procedures MCNP4B as simulation tools and draw a conclusion. In order to understand the effect of multiple scattering, which induced by the pipeline material and the cooling water. Based on the data produced by the procedures simulating, As to samples of each angle, respectively we give several curves, as the thickness of the pipeline or thickness of cooling water changes, it reflect the trend of the counts of generated ¹⁵³Sm,...