Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
大図 章; 中村 龍也; 高瀬 操; 倉田 典孝; 春山 満夫; 呉田 昌俊; 曽山 和彦; 瀬谷 道夫
Proceedings of 2013 IEEE Nuclear Science Symposium and Medical Imaging Conference Record (NSS/MIC), 4 Pages, 2013/00
日本原子力研究開発機構では、保障措置用He-3中性子検出器の代替として固体シンチレータを用いた検出器を開発している。その検出器は、アルミニウム製の矩形チューブ(長さ約300mm, 32
32mm)、シンチレータシート(39mm250mm)、及び二つの光電子増倍管から構成される。シンチレータシートは、そのアルミニウム管内の矩形断面の斜め方向に設置され、光電子増倍管は管の両端に設置される。現在、検出効率としてHe-3検出器の約50%の値が得られ、かつ
線感度として510
が達成されている。この検出器の基本性能は、検出器管内のシンチレータ光の導光特性に大きく依存する。検出器管内のシンチレータ面から光電子増倍管までの光の伝送効率を光線追跡シミュレーションで評価した。その結果について、試験結果と比較して報告する。
山口 充孝; 長尾 悠人; 河地 有木; 藤巻 秀; 神谷 富裕; 小高 裕和*; 国分 紀秀*; 武田 伸一郎*; 渡辺 伸*; 高橋 忠幸*; et al.
Proceedings of 2013 IEEE Nuclear Science Symposium and Medical Imaging Conference Record (NSS/MIC), 3 Pages, 2013/00
A Monte Carlo simulation system was developed to estimate the response of Compton camera against -ray emissions from RI spots in a PET-standard human-body phantom. The quality of the three-dimensional imaging program for the Si/CdTe Compton camera to reconstruct the image of the RI spots in a phantom was evaluated by the system, when the phantom has three hot sphere-regions with the same known RI density and different diameters, in other words, different known intensities. The density values of the hot regions reconstructed by the three-dimensional imaging program for the Compton camera were consistent to the known intensities of the RI. It demonstrates sufficient quality of the program for Si/CdTe Compton camera to image RI spots in the phantom.
山口 充孝; 鳥飼 幸太*; 河地 有木; 島田 博文*; 佐藤 隆博; 長尾 悠人; 藤巻 秀; 国分 紀秀*; 渡辺 伸*; 高橋 忠幸*; et al.
Proceedings of 2013 IEEE Nuclear Science Symposium and Medical Imaging Conference Record (NSS/MIC), 2 Pages, 2013/00
We studied a new method to monitor a beam range in heavy-ion radiation therapy on the basis of measurement of low energy photons emitted from a track of the ion beam. A 290 MeV/u carbon beam was injected into a cylindrical water phantom. A CdTe semiconductor detector with a lead slit having a width of 2 mm was placed at a side of the phantom. In order to measure the position dependence of the low energy photon count, the beam range was varied by changing the energy of injected ions using a binary energy degrader placed about 100 cm upstream of the beam focal point. The measured photon count decreased when the detector got closer to the end point of the beam range and the derivative of the photon count values sharply changed within a depth variation of a few mm in front of the range position. This was explained by our theoretical study assuming secondary electron bremsstrahlung. These results indicate that this new method could be useful to estimate the range position from the observation of bremsstrahlung with an accuracy of a few mm.
