Development of wide view gamma-ray Imaging Detector

宽视场伽马射线成像探测器的研制

基本信息

批准号：
12354002
负责人：
TANIMORI Toru
金额：
$ 23.96万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2002
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12354002/
关键词：
MeV gamma-rays gamma-rays Imaging Compton Scattering MSGC Gas Detector Anguar Camera TPC γ線イメージングコンブトン散乱アンガーガメラ γ線イナージング

项目摘要

We have proposed the new imaging method of MeV gamma rays. By measuring the direction and energy of not only a scattered gamma ray but also a scattered electron, the direction of an incident gamma ray would be principally reconstructed event by event, and a full imaging would be realized. Furthermore, one of two measured (zenith and azimuthal) angles of a scattered electron gives co an additional redundancy which enable us to reject almost all the background events by kinematic fitting. In order to detect such a fine track of the recoil electron, a fine imaging gas detector made by the micro printed board technology was proposed here.In order to obtain 3-D track of a scattered electron, the micro Time Projection Chamber(TPC) has been developed, which measures the position of the track in a few hundred micron meter pitch successively. This TPC consists of the new type of a gas proportional chamber : Micro Pixel Gas Chamber (MPGC) which is a one of wireless gas chamber and expected to be more robust and reliable than Micro Strip Gas Chamber. Here 10cm×10cm 2D-MPGC with a 400 μm pitch pixel was developed, and the high gain of 〜 15000 and the stable operation as a micro TPC with a moderated gain of 〜 5000 during one month have been achieved. Also a compact Anguar camera consisting of a 10cm×10cm×2.5cm NaI scintillator and a 5×5 one-inch phototube array was constructed to detect a recoil gamma ray. Using the micro TPC and the Anguar camera, we successfully obtained the first gamma-ray image by the full reconstruction of the direction of gamma rays event by event. Although obtained angular resolution of 〜 30°is not so good due to the inefficiency of the MPGC, it is the first time in the world to demonstrate the possibility of full gamma ray imaging.

我们提出了新的MeV伽马射线成像方法，通过测量散射伽马射线和散射电子的方向和能量，主要逐个重建入射伽马射线的方向，并进行全成像。此外，散射电子的两个测量角（天顶角和方位角）之一提供了额外的冗余，这使我们能够通过运动学拟合来拒绝几乎所有背景事件，以便检测到如此精细的轨迹。为了获得散射电子的3D轨迹，开发了微型时间投影室（TPC），它可以测量散射电子的位置。该TPC由新型气体比例室组成：Micro Pixel Gas Chamber (MPGC)，它是一种无线气体室，预计比Micro Strip更加坚固可靠。毒气室在这里。开发了像素间距为 400 μm 的 10cm×10cm 2D-MPGC，并实现了约 15000 的高增益和约 5000 增益的微型 TPC 在一个月内的稳定运行，并且还由紧凑型 Anguar 组成。构建了10cm×10cm×2.5cm NaI闪烁体和5×5一英寸光电管阵列的相机来探测使用微型 TPC 和 Anguar 相机，我们通过逐事件完全重建伽马射线方向，成功获得了第一张伽马射线图像，尽管由于原因，获得的约 30° 的角分辨率不太好。尽管MPGC效率低下，但它在世界上首次展示了全伽马射线成像的可能性。