The GTAF Detector Shield Body System MCNP Analog Computation Design

In order to get (n,γ) accurate reaction capture cross section, China Institute of Atomic Energy ( CIAE ) GTAF (gamma-ray total absorption facility) group are developing a detecting set of 4Ï€full absorption.This paper which makes use of MCNP procedure and bases on GTAF detector, takes analog computation design work to the GTAF shield body system. Firstly, we designed the neutron source shield body and the collimator, through simulation in the BaF₂ detector system . It is an important figure of neutron source's performance, while the neutron source shield-body and neutron stream collimator provide a perfect experiment background and neutron stream respectively in this neutron capture cross reaction. Secondly, we took simulation and designation to the neutron absorber. The neutron absorber which is the place of neutron capture reaction is in the sphere shell. Scientific simulation and designation is important to neutron absorption filter, in order to get the correct y signal which come from BaF₂ crystal detector, make it absorb scatter neutron, recede y background, and reduce the excursion of y spectrum. Finally, we designed the neutron acquirer through simulation. the design of neutron acquirer is important, it can reduce scatter neutron which in sample,BaF₂ crystal and on edge, also include extra photon of background, so it must be more exactly.We take MCNP program in simulation and designation. MCNP program is a large multi-function particle Monte Carlo transport program, it can compute neutron,electron,photon transport and coupling transport between them, It has superiority in radiation shield of nuclear physics and relative design of neutron-photon transport.Finally, we designed the GTAF detector shield body which include neutron source collimator, neutron absorber in sample and neutron acquirer. After simulation all the performances get into the anticipated designing effects. All the simulations and designations work will provide well conditions for construction of GTAF detector shield body system in later.