国产无机闪烁晶体LaCl_3∶Ce的探测能力和时间响应测量

Measurements of Detecting Capability and Time Response for Homemade LaCl_3∶Ce Inorganic Scintillator

以国产的掺铈氯化镧(LaCl3∶Ce)闪烁晶体与线性电流大于1.5 A的光电倍增管构成闪烁探测器,利用60Co、137Cs放射性标准源场,实验测量这种探测器对γ辐射的探测能力,并与同情况NaI∶Tl闪烁探测器进行比对;利用266 nm单色激光和ns级的γ脉冲辐射分别对这种闪烁体的光致激发、辐射激发的时间响应性能进行测量。测量结果表明:国产新型LaCl3∶Ce无机闪烁晶体样品构成的探测器对1.25 MeV、0.66 MeVγ射线的探测能力平均约为同情况NaI∶Tl闪烁探测器的103%,高的已超过了同尺寸NaI∶Tl构成的闪烁探测器;266 nm单色激光光致激发时间响应波形前沿、半高宽、后沿和衰减常数分别为1.05 ns、17.42 ns、54.30 ns和24.61 ns,ns级的γ脉冲辐射激发的时间响应波形前沿、半高宽、后沿和衰减常数分别为1.52 ns、21.99 ns、75.13 ns和34.19 ns。

Detecting capability for γ irradiation and time response of a kind of detector,which is composed of the homemade LaCl3∶Ce inorganic scintillator coupled optically with a PMT with above 1.5 A line current,were studied in this paper.The detecting capability of the homemade LaCl3∶Ce scintillator was measured and contrasted with commercial NaI∶Tl scintillator using 60Co and 137Cs radioactive sources.The result shows that its detecting capability avarage is about 103% of that of NaI∶Tl with the same sizes,the light output of some LaCl3∶Ce scintillators is even more than NaI∶Tl with the same volume.The time response waveforms of the homemade LaCl3∶Ce scintillators were studied experimentally under the excitation of 266 nm laser light and pulsed γ rays with the FWHM of several ns,respectively.The result of the laser experiment shows that the raise time,FWHM,fall time and decay constant of the response waveform are 1.05 ns,17.42 ns,54.30 ns and 24.61 ns,respectively.And the result of the pulsed γ rays experiment shows that their corresponding values are 2.52 ns,21.99 ns,75.13 ns and 34.19 ns,respectively.