BESⅢ漂移室模型老化实验中水汽作用研究

Experimental study of the aging of BESⅢ drift chamber prototype

气体探测器在辐照下的老化一直为人们所关心。文章报道了分别用^(55)Fe 5.9keV X射线和^(90)Srβ射线对BESⅢ漂移室模型所作辐照老化实验中水汽作用的研究。从阳极电流和^(55)Fe 5.9keV X射线全能光电峰位随累积电荷量的变化,在加有水汽情况下分别得到大单元老化率为-0.06%/(mC/cm)与-0.30%/(mC/cm)及小单元老化率为-0.15%/(mC/cm)与-0.18%/(mC/cm)。并在同一老化实验过程的前后段分别不加水汽和加水汽作了老化率的比较,实验结果显示混合气体中有少量水汽加入有利于减低老化。在老化后的丝室加入水汽后发现水汽对老化后的探测器有一定治疗作用。

The aging of the gas detectors under irradiation is concerned about for decades. The aging of BESⅢ drift chamber prototype was studied experimentally by the irradiation of ^55Fe X-ray and ^90Sr βray. The aging rates R -0.06%/（mC/cm） and -0.15%/（mC/cm） from anode current and -0.30%/（mC/cm） and -0.18%/（mC/cm） from full energy photo electron peak position of ^55Fe 5.9 ke V X-ray as function of accumulated charge were obtained for big and small cell, respectively. Farther more we compared the aging rates of the different part of same one experiment which the water bubbler at the first part was added and the bubbler at the second part was removed. The results show us that the few vapor of water is benefit for decreasing ageing. After adding the vapor of water to the aged wire chamber, we found that the gain of the chamber increased and that the vapor of water can cure the aged chamber.