【摘要】 我所研制了BPS型TE-TE球形空腔电离室。本工作测量了这些电离室的基本性能。饱和特性的测量结果表明,在⁶⁰Co光子场中Q_B/Q_V与V^-2之间,关系是线性的,相关系数极接近于1,由此得出了饱和修正因子。对于15MeV中子和⁶⁰Co光子确定了自由空气比释动能的壁厚修正因子,各自为（0.6±0.9）·10^-2mm^-1和（0.49±0.35）·10^-2mm^-1当射线入射角度范围在0-120°范围时,室响应相对变化对于⁶⁰Coγ射线不大于0. 5％,而对于15 MeV中子大约为1％。还研究测定了自由空气照射电离室在光子场与中子场中柄散射的影响,测量和计算了用TE气体和空气分别作为工作气体时电离室读数之比值,结果相符。更多还原

【Abstract】 The model BPS TE-TE spherical cavity ionization chambers havebeen constructed in Institute of Biophysics,,Academia Sinica. The basic performencesof the chambers have been measured. The results of measurement of the saturationcharacteristics show that the relation between Q_s/Q_v and V^-2 is linear in ⁶⁰Co pho-ton field and between I_s/I_v and V^-1 is linear in D +T neutron photon mixed field.The correlation coefficients is extremely close to 1. The saturation correction factorswere obtained. The wall thickness correction factors for determination of free-in-air are （0. 60±0. 88 ） ×10^-2 mm^-1 and （0. 49± 0. 35 ）× 10^-2 mm^-1 for 15 MeV neutrons and ⁶⁰Cophotons respectively. The relative change of the response with angle of irradiation isnot larger than 0.5 per cent when incident degrees of the radiation is in the rangeof 0～120°for the ⁶⁰Co gamma rays but is about one per cent for the 15 MeV neu-trons. The influences of stem scatter and radiation sensitivity of stem were studiedin photon and neutron fields for irradiation free-in-air. The ratios of readings withTE gas and air were measured for TE-gas and calculated with the ratios of CH₄,CO₂, N₂ given by Williams. The values measured and calculated are coincident. Theeffect of TE gas flow rate on the readings of the chamber was observed.更多还原