采用标称体积为10 cm3圆柱型空腔电离室对 Cs-137空气比释动能进行绝对测量。使用 Monte Carlo 模拟计算和实验两种方法对电离室壁修正因子 k w和轴向不均匀修正因子 kan 进行对比研究。结果显示，使用等效壁厚的实验外推法确定的 k w值比 MC 计算得到的值小0.1％，实验方法确定的 kan 值比 MC 计算得到的值小0.63％。两种方法相互印证，给出的修正系数值之间的误差可以接受，由于重复实验不可避免将引入其他误差因素，且 MC计算方法简便可重复性高，最终选取 MC 计算结果为 kw、kan确定值。%How to use nominal 10 cm3 cylindrical cavity ionization chamber is disscussed to give absolute measurement to the Cs-137 air kerma. The wall correction factor kw and the axial non - uniformity correction factor kan is determined by both the experimental method and Monte Carlo( MC)calculation. The results show that the wall correction factor kw determined by geometry thickness extrapolation method is less than 0. 091% compared with that by the MC calculation,the axial non - uniformity correction factor kan determined by the experimental method is less than 0. 63% compared with that by the MC calculation. The error between the two values is acceptable. The repeated experiment will inevitably introduce other error factors,and MC calculation method is simple and high repeatability. Eventually MC calculation results are selected for kw ,kan value.
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