Development of wideband X-ray and gamma-ray spectrometer using transmission-type, large-area APD
Development of wideband X-ray and gamma-ray spectrometer using transmission-type, large-area APD
复制标题
DOI：
10.1016/j.nima.2007.08.238
复制
发表时间：
2007-11
影响因子：
1.4
通讯作者：
S. Tanaka;J. Kataoka;Y. Kanai;Y. Yatsu;M. Arimoto;M. Koizumi;N. Kawai;Y. Ishikawa;S. Kawai;N. Kawabata
中科院分区：
文献类型：
--
作者：
S. Tanaka;J. Kataoka;Y. Kanai;Y. Yatsu;M. Arimoto;M. Koizumi;N. Kawai;Y. Ishikawa;S. Kawai;N. Kawabata
雪崩光电二极管（APD）是一种高性能、紧凑的光传感器，最近应用于实验物理的各个领域。在多种类型的 APD 中，穿透式 APD 在直接 X 射线检测方面具有优势，这要归功于其放大区域前面的厚耗尽层 (⩾100μm)。这种类型的 APD 对来自伽马射线闪烁体的微弱闪烁光也很敏感，量子效率高达 ∼80%（在 λ≃500nm）。在本文中，我们提出了一种紧凑型X射线到伽马射线探测器的新颖设计，广泛适用于1keV到数百keV之间。该原型由与尺寸为 4×4×4mm3 的立方 CsI(Tl) 晶体光学耦合的穿透式 APD（传输型）组成。通过将脉冲形状辨别技术应用于 APD 输出，我们成功地区分了在 APD (1–40keV) 内直接检测到的 X 射线信号，以及紧邻 APD 后面的 CsI(Tl) 闪烁体 (10–800keV) 中吸收的伽马射线信号。在 +20∘C 测量时，5.9keV X 射线、32keV X 射线和 662keV 伽马射线的最佳半高宽能量分辨率分别为 15.1±0.2%、6.6±0.4% 和 7.6±0.1%。这种堆叠配置对于空间科学和核医学领域的各种未来应用都是可行的。
The avalanche photodiode (APD) is a high-performance and compact light sensor recently applied in various fields of experimental physics. Among several types of APDs, the reach-through APD offers an advantage in direct X-ray detection, thanks to its thick depletion layer (⩾100μm) in front of the amplification region. This type of APD is also sensitive to weak scintillation light from gamma-ray scintillators with a high quantum efficiency of ∼80% (at λ≃500nm). In this paper, we propose a novel design of a compact X-ray-to-gamma-ray detector widely applicable between 1keV and several hundreds of keV. The prototype consists of a reach-through APD (transmission type) optically coupled with a cubic CsI(Tl) crystal 4×4×4mm3in size. By applying the pulse shape discrimination technique to the APD output, we successfully discriminated the X-ray signals directly detected within the APD (1–40keV), and gamma-ray signals absorbed in a CsI(Tl) scintillator (10–800keV) located immediately behind the APD. Optimum FWHM energy resolutions of 15.1±0.2%, 6.6±0.4%, and 7.6±0.1% were obtained for 5.9keV X-rays, 32keV X-rays, and 662keV gamma rays, respectively, measured at +20∘C. This stacked configuration is viable for various future applications in space science and nuclear medicine.