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Evaluation of the OpenPET detector for in-beam imaging using Zr doped GSO crystals under carbon beam irradiation
https://repo.qst.go.jp/records/70755
https://repo.qst.go.jp/records/7075587ccbce9-7b09-4477-b16b-f619b2bb9bcf
| Item type | 会議発表用資料 / Presentation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2012-05-22 | |||||
| タイトル | ||||||
| タイトル | Evaluation of the OpenPET detector for in-beam imaging using Zr doped GSO crystals under carbon beam irradiation | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_c94f | |||||
| 資源タイプ | conference object | |||||
| アクセス権 | ||||||
| アクセス権 | metadata only access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
| 著者 |
Nishikido, Fumihiko
× Nishikido, Fumihiko× Inadama, Naoko× Hirano, Yoshiyuki× Satou, Shinji× Yoshida, Eiji× Inaniwa, Taku× Murayama, Hideo× Yamaya, Taiga× 錦戸 文彦× 稲玉 直子× 平野 祥之× 佐藤 眞二× 吉田 英治× 稲庭 拓× 村山 秀雄× 山谷 泰賀 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | We are developing PET detectors of the OpenPET for in-beam imaging in carbon ion therapy. Some detector components of the OpenPET detector are changed from the detector used in the small OpenPET prototype which consists of LGSO crystals and a conventional position sensitive photomultiplier tubes. Zr doped GSO was used as scintillation crystals to avoid influence of self-luminescence of LGSO degrading image quality in in-beam imaging. However, light yield of GSO crystal is lower than that of LGSO. Photomultiplier tubes with the super bialkali photocathode realizing 30% higher quantum efficiency than conventional bialkali photocathodes are used to compensate decrease of light yield. In the case of the OpenPET geometry, a part of light ions generated by fragmentation in a target incident into detectors positioned at downstream of the target. As a results, performance of these detectors is possibly degraded in the measurement under carbon beam irradiation. In this presentation, we constructed a prototype of the OpenPET detector and evaluated its performance under carbon beam irradiation. The OpenPET detector consists of a GSOZ crystal block and 64ch position sensitive photomultiplier. The crystal block consists of four layers of a 16 x 16 array. The size of the crystals is 2.8mm x 2.8mm x 7.5mm. The 64 channel anode outputs were fed to a resistor chain circuit, reduced to four channels and recorded by analog digital converters. We conducted in-beam experiments with the OpenPET detector in HIMAC. The energy and intensity of the C-12 beam were 290MeV/u and 1.0x10^8 particle per second (pps). Carbon ions entered to a water phantom through an ionization chamber used as a beam intensity monitor. All of the primary carbon ions were stopped in the water. The OpenPET detector was positioned 30cm apart from the backside of the water phantom at an angle of 30 degree. The performance of the prototype detector was evaluated by measuring the annihilation photons from Na-22 point sources by coincidence measurement. The detail of the experimental setup is shown in fig. 1. Figure 2 shows 2D position histograms of OpenPET detector under the 1.0x10^8 pps irradiation condition. While the 2D position histogram is slightly degraded comparing with the 2D position histogram before carbon beam irradiation, the crystals on all four layers can be identified. The energy resolutions of 14.2% (1st layer), 15.7% (2nd layer), 15.2% (3rd layer) and 14.6% (4th layer) were obtained for single crystal elements by defining region of interests on the 2D position histogram. These results indicate that the OpenPET detectors can normally work in in-beam imaging by some modification from the previous detector. We constructed the prototype of the OpenPET detector and evaluated its performance under carbon beam irradiation in HIMAC. As a result, the sufficient performance as PET detectors was obtained under the 1.0x10^8 pps irradiation condition. |
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| 会議概要（会議名, 開催地, 会期, 主催者等） | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | PTCOG51, 51th Annual Meeting of Particle Therapy Co-Operative Group | |||||
| 発表年月日 | ||||||
| 日付 | 2012-05-19 | |||||
| 日付タイプ | Issued | |||||
