Simulation input spectrum of triple-axis spectrometer and parameter optimization
Abstract
According to the layout and parameters of Cold Neutron Source (CNS) and neutron guides (NG),the parameters of input neutron-beam such as flux,divergence and homogeneity,are calculated by Monte-Carlo simulation at the exit of NG where a neutron triple-axis spectrometer will be built.The results showed the distance(L)between CNS and the entrance of NG should not be less than 0.1m.mo- reover,when the L equal 0.5m the flux increases to the maximal 3.96 10~8cm~(-2) s~(-1).The flux and beam divergence increase slightly as supermirror factor m increasing from 1.5 to 3.0,the vertical maximal di- vergence and flux increase 87.7% and 25% respectively.The vertical and horizontal divergence can be described by a Gaussian function.The horizontal and vertical maximal divergence are 0.85°and 0.81°when m is 1.5,L is 2m,with the flux up to 2.86×10~8 cm~(-2)s~(-1).We give the optimum neutron guides pa- rameter for the TAS.