The effect of detector disturb and the shell of the detector and construction material is not distinct . the low absorb cross section material is used to 235u - fission chamber . the low z material is used in experimental bracket and shielding material and the material is used less 获得了探测器之间扰动、探测器外壳、支架材料对信号中子测量无明显影响的结果;对~ ( 235 ) u裂变电离室,需采用中子吸收截面低的材料,对实验装置的支撑材料和屏蔽材料宜选用低z材料且尽量减少用材。