CVD金刚石微剂量仪的辐射优化研究

Investigation on priming effect of CVD diamond microdosimeter

金刚石材料具有大的能带间隙、快的电荷收集和低的介电常数等,在较恶劣的实验环境下(如对于超大规模的强子对撞机和同步辐射加速器进行近距离、高辐射条件下的信号探测),有望成为常规的硅、砷化镓等探测器的替代品。为了改进金刚石探测器的性能,本文采用5MeV质子对CVD金刚石微剂量仪进行了辐照,并采用侧向微束离子诱导电荷(IBIC)技术分析研究其性能。实验发现:①经46 Gy质子辐照后金刚石探测器的收集效率得到了很大的改善;②收集效率和计数的均匀性也得到了提高,尤其是计数的均匀性,在窄条宽很小情况下其均匀性已达95%以上。可见用质子辐照CVD金刚石是提高其性能的有效途径之一。

The CVD diamond microdosimeter is an ideal substitute for common Si and GaAs detectors under extremely strong radiation experimental environment due to its high band gap energy, fast charge collection, low dielectric constant and high hardness. In order to improve its character, a CVD diamond microdosimeter was irradiated by protons of 46 Gy, and the lateral micro-ion beam induced charge (IBIC) technique was utilized to characterize it in low beam current (~fA). It was clearly shown that charge collection efficiency was greatly improved after proton irradiation with that dose. Moreover, the uniformities of both counting performance and collection efficiency were enhanced. Proton irradiation of 46 Gy has been proved to be an effective way to prime a CVD diamond.