基于N型同轴HPGe探测器获取过滤X射线注量谱

构建ISO 4037?1以外的过滤X射线参考辐射需射束注量谱计算平均能量、分辨率和转换系数等参数。为建立过滤X射线注量谱获取方法，采用N型同轴HPGe探测器测量了N?40?N?250窄谱系列过滤X射线参考辐射并得到了脉冲幅度谱，使用Geant4模拟了探测器对放射源的响应并用实测能谱进行了验证，进而建立了响应矩阵，并通过MAXED软件解谱计算得到了射束的注量谱。由解谱所得注量谱计算的空气比释动能到周围剂量当量和个人剂量当量的转换系数与ISO 4037?3推荐值的相对偏差在0?06%?2?55%之间。

Obtaining Fluence Spectra of Filtered X-ray Based on N-type Coaxial HPGe Detector

Fluence spectrum is required to calculate parameters such as average energy, resolution and conversion coefficient when filtered X?ray reference radiation beyond ISO 4037?1 is to be constructed. Aiming to establish the method of obtaining fluence spectrum of filtered X?ray, reference radiations from N?40 to N?250 were measured with N?type coaxial HPGe detector and pulse height spectra were collected. The detector’s responses to several radioactive sources were simulated with Geant4 and verified by measured spectra. Then the response matrix was constructed, and fluence spectra were unfolded with MAXED software. The conversion coefficients from air KERMA （kinetic energy released in material） to ambient dose equivalent and personal dose equivalent were calculated with the unfolded spectra and compared with those recommended by ISO 4037?3. The results show that the relative deviations are within 0?06%?2?55%.