基于电离室阵列测量X射线半值层实验的研究

目前测量X诊断医用辐射源的半值层的方法基本采用人工叠加吸收片,测量出射线穿透不同厚度吸收片后的照射量,从而采用绘图方法或插入法计算X诊断医用辐射源的半值层1],该方法曝光次数多,光机损伤大,操作不方便。为了准确测量诊断X射线的辐射质,减少工作量,设计一种电离室阵列测量方案,通过单次测量不同厚度吸收片下的剂量值,根据衰减曲线插值计算得到给定千伏下的半值层。通过测试比较,电离室阵列测量方案操作简单,数据准确,曝光次数少,能减少光机的损耗,具有较高的应用前景。

Research on measurement method of half-value layer of X-ray based on ionization chamber array

As the current method getting the half-value layer of X diagnostic medical radiation is using the artificial overlay absorber,it can get the exposure of X-ray through the different thickness absorber and get the half-value layer of X diagnostic medical radiation by drawing or insertion.However,more times exposure and more damage on machine make it not be convenient in operation.Through collecting the dose of the different thickness absorber with the method of the ionization chamber measurement array,the decay curve can be obtained and orderly the half value layer can be calculated.The proposed method is simple with less exposure times than the commonly used by the artificial superposition of the absorption of films,can reduce the wear of ray machine and is easy to operate with.So it has wide application prospects.