组织等效电离室光子定度的研究及其验证

Calibration of a tissue-equivalent ionization chamber and theexperimental evidence

本文详细地研究了γ定度的方法,从而求得了空腔中气体的质量,以计算吸收剂量。还直接测量了空腔的体积,由气体的密度推出了空腔气体的质量。这两种方法得到的结果在0.5％内符合。这表明:本文采用的定度程序、引用的物理常数是正当的。本文介绍的测定气体质量的方法亦可作为测定(Wc/e)·S_(m,g)的一个实验方法。

A calibration procedure in a photon beam for a tissue-equivalent ionization chamber is described.To verify the calibration we also measured the volume of cavity and obtai-ned the mass of gas in the cavity directly using gas density.The agreement between the two methods is better than 0.5%, showing that the procedure and the physical parameters used in the calibration are proper. The method used for measuring the mass of gas in the cavity is also valid for the experimental determination of (Wc/e)· Sm,g.