周围剂量当量仪的研制

A design of ambient dose equivalent dosimeter and its dosimetric performance

周围剂量当量仪研制是根据国际辐射单位和测量委员会（ＩＣＲＵ）３９号报告推荐的周围剂量当量而设计的一种数字化智能型辐射防护仪。方法采用能量补偿对探测器进行能响校正。结果补偿结果使得探测器在４７～２３０ｋｅＶ与ＩＳＯ推荐的Ｈ＊（１０）／Ｋａ值误差在５％以内。本文重点描述了周围剂量当量仪探测器部分的工艺结构和剂量学性能以及电子学测量部分的主要功能。结论通过实际应用我们初步获得的结论是由于该仪器可直接测量周围剂量当量，稳定性好且具有自动取平均值特点，它可做为实验室校准用测量仪器，又由于该仪器体积小，电池供电，读数面板又有背光功能。

Objective\ To design an ambient dose equivalent dosimeter with digital display for radiation protection,which is based on the definition of the new operational radiation quantity for environmental monitoring—ambient dose equivalent recommended by the International Commission on Radiation Units and Measurements (ICRU) Report 39 .Methods\ Considering the energy response of the instrument, the inner wall of ionizing chamber is coated with gum graphite added with a bit of metal powder.Results\ Using this chamber,measurement of H *(10) for photon radiation with unknown spectrum distribution is possible in the energy range from 47 keV to 230 keV with an uncertainty of better than 5%.The configuration,technology and dosimetric performance of the chamber and automatic functions of the reader are presented.Conclusion\ The ambient dose equivalent dosimeter can be used as not only a working reference dosimeter,but also a field dosimeter for radiation protection because the readings are expressed directly in ambient dose equivalent and averaged automatically in the period of measurement.Also, its power is supplied by battery for the portable purpose and the readings are displayed on the screen with light background for dim field.