這項(xiàng)工作旨在使用混合像素X射線探測(cè)器來表征超高劑量脈沖 (UHDpulse) 電子束。使用Timepix3 (TPX3) ASIC 芯片測(cè)量來自脈沖 15–23 MeV 電子束產(chǎn)生的二次輻射場(chǎng)的組成、空間、時(shí)間和光譜特性。面臨的挑戰(zhàn)是需要開發(fā)一款緊湊型探測(cè)器，可以在這種高通量短脈沖場(chǎng)上提取光譜和劑量信息。對(duì)于二次光束測(cè)量，將厚度為 1 和 8 cm 的 PMMA 板放置在電子束前面，脈沖持續(xù)時(shí)間為 3.5 μs。作者將 Timepix3 探測(cè)器（使用100 和 500 μm 厚度的硅sensor）放置在移動(dòng)臺(tái)上，在光束軸的各個(gè)橫向位置采集數(shù)據(jù)。在 FLEXI 配置中使用探測(cè)器可實(shí)現(xiàn)適當(dāng)?shù)脑粶y(cè)量和最小的自屏蔽。初步結(jié)果證明了該探測(cè)器具有測(cè)量以短脈沖形式傳遞的電子束的單個(gè) UHD 脈沖的能力。此外，使用每個(gè)像素的兩條信號(hào)鏈可以在混合輻射場(chǎng)中估計(jì)距束芯不同距離處的粒子通量和散射劑量率 (DR)。

Stray radiation produced in FLASH electron beams characterized by the MiniPIX Timepix3 Flex detector

This work aims to characterize ultra-high dose rate pulses (UHDpulse) electron beams using the hybrid semiconductor pixel detector. The Timepix3 (TPX3) ASIC chip was used to measure the composition, spatial, time, and spectral characteristics of the secondary radiation fields from pulsed 15–23?MeV electron beams. The challenge is to develop a single compact detector that could extract spectrometric and dosimetric information on such high flux short-pulsed fields. For secondary beam measurements, PMMA plates of 1 and 8?cm thickness were placed in front of the electron beam, with a pulse duration of 3.5 μs. Timepix3 detectors with silicon sensors of 100 and 500?μm thickness were placed on a shifting stage allowing for data acquisition at various lateral positions to the beam axis. The use of the detector in FLEXI configuration enables suitable measurements in-situ and minimal self-shielding. Preliminary results highlight both the technique and the detector's ability to measure individual UHDpulses of electron beams delivered in short pulses. In addition, the use of the two signal chains per-pixel enables the estimation of particle flux and the scattered dose rates (DRs) at various distances from the beam core, in mixed radiation fields.

原文信息：Oancea, C., et al. "Stray radiation produced in FLASH electron beams characterized by the MiniPIX Timepix3 Flex detector." Journal of Instrumentation 17.01 (2022): C01003.

文中使用的是來自捷克Advacam公司的光子計(jì)數(shù)、混合像素X射線探測(cè)器 (點(diǎn)擊了解詳情)。