Recent progress of MPPC-based scintillation detectors in high precision X-ray and gamma-ray imaging
Recent progress of MPPC-based scintillation detectors in high precision X-ray and gamma-ray imaging
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DOI：
10.1016/j.nima.2014.11.004
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发表时间：
2015-06-01
影响因子：
1.4
通讯作者：
Yamamoto, S.
中科院分区：
文献类型：
--
作者：
Kataoka, J.;Kishimoto, A.;Yamamoto, S.
多像素光子计数器（MPPC）是一种具有广泛应用前景的光传感器，不仅在物理实验中，而且在核医学、工业甚至高能天体物理中都有广泛的应用。在本文中，我们介绍了基于mppc的闪烁探测器的现状和最新进展，例如(1)高精度x射线和伽马射线光谱图像传感器，(2)具有MRI， TOF和DOI测量能力的下一代PET探测器，以及(3)用于环境辐射调查的紧凑型伽马相机。我们首先提出了一种制造具有超精细分辨率（0.2 mm/像素）的Ce:GAGG闪烁片（1或2 mm厚）的新方法，使用切片锯切割以产生50 μ m宽的微凹槽。当该板与大面积MPPC阵列光学耦合时，对122 keV的伽马射线获得了0.48 mm的空间分辨率和14%的能量分辨率。因此，探测器可以作为一种方便的“多色”成像设备，可以潜在地用于未来的SPECT和光子计数CT。然后，我们展示了一个基于mppc的高分辨率PET扫描仪的原型系统，即使在4.7 t的强磁场下，也可以实现类似或等于1 mm （FWHM）的空间分辨率。我们开发了一个前端ASIC，用于未来的TOF-PET扫描仪，具有16通道读出，达到489 ps （FWHM）的符合时间分辨率。通过测量耦合在闪烁晶体块两端的双面MPPCs的脉冲高度比，提出了一种具有伽马射线doi测量能力的模块设计。最后，我们提出了一种由Ce:GAGG闪烁体阵列与薄MPPC阵列耦合组成的双平面康普顿相机的概念。由于MPPC设备的薄而紧凑的特点，与福岛使用的传统pmt针孔相机相比，相机不仅尺寸小（14 x 14 x 15 cm），重量轻（1.9 kg），而且灵敏度优异。最后，我们简要介绍了最近与Hamamatsu Photonics K.K.合作开发的一种新产品，该产品通过结合doi分段闪烁体阵列，在662键处提供了改进的灵敏度和Delta θ的角分辨率，类似于8度（FWHM）。(C) 2014 Elsevier B.V.版权所有
The multi-pixel photon counter (MPPC) is a promising light sensor for various applications, not only in physics experiments but also in nuclear medicine, industry, and even high-energy astrophysics. In this paper, we present the current status and most recent progress of the MPPC-based scintillation detectors, such as (1) a high-precision X-ray and gamma-ray spectral image sensor, (2) next-generation PET detectors with MRI, TOF, and DOI measurement capabilities, and (3) a compact gamma camera for environmental radiation surveys. We first present a new method of fabricating a Ce:GAGG scintillator plate (1 or 2 mm thick) with ultra-fine resolution (0.2 mm/pixel), cut using a dicing saw to create 50 mu m wide micro-grooves. When the plate is optically coupled with a large-area MPPC array, excellent spatial resolution of 0.48 mm (FWHM) and energy resolution of 14% (FWHM) are obtained for 122 keV gamma rays. Hence, the detector can act as a convenient "multi-color" imaging device that can potentially be used for future SPECT and photon-counting CT. We then show a prototype system for a high-resolution MPPC-based PET scanner that can realize similar or equal to 1 mm (FWHM) spatial resolution, even under a strong magnetic field of 4.7 T. We develop a front-end ASIC intended for future TOF-PET scanner with a 16-channel readout that achieves a coincidence time resolution of 489 ps (FWHM). A novel design for a module with DOI-measurement capability for gamma rays is also presented by measuring the pulse height ratio of double-sided MPPCs coupled at both ends of scintillation crystal block. Finally, we present the concept of a two-plane Compton camera consisting of Ce:GAGG scintillator arrays coupled with thin MPPC arrays. As a result of the thin and compact features of the MPPC device, the camera not only achieves a small size (14 x 14 x 15 cm(3)) and light weight (1.9 kg) but also excellent sensitivity, compared to the conventional PMT-based pinhole camera used in Fukushima. Finally, we briefly describe a new product recently developed in conjunction with Hamamatsu Photonics K.K. that offers improved sensitivity and angular resolution of Delta theta similar to 8 degrees (FWHM) at 662 key, by incorporating DOI-segmented scintillator arrays. (C) 2014 Elsevier B.V. All rights reserved.