Stevenson Andrew W, Crosbie Jeffrey C, Hall Christopher J, Häusermann Daniel, Livingstone Jayde, Lye Jessica E
Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168, Australia.
School of Science, RMIT University, GPO Box 2476, Melbourne, Victoria 3001, Australia.
J Synchrotron Radiat. 2017 Jan 1;24(Pt 1):110-141. doi: 10.1107/S1600577516015563.
A critical early phase for any synchrotron beamline involves detailed testing, characterization and commissioning; this is especially true of a beamline as ambitious and complex as the Imaging & Medical Beamline (IMBL) at the Australian Synchrotron. IMBL staff and expert users have been performing precise experiments aimed at quantitative characterization of the primary polychromatic and monochromatic X-ray beams, with particular emphasis placed on the wiggler insertion devices (IDs), the primary-slit system and any in vacuo and ex vacuo filters. The findings from these studies will be described herein. These results will benefit IMBL and other users in the future, especially those for whom detailed knowledge of the X-ray beam spectrum (or `quality') and flux density is important. This information is critical for radiotherapy and radiobiology users, who ultimately need to know (to better than 5%) what X-ray dose or dose rate is being delivered to their samples. Various correction factors associated with ionization-chamber (IC) dosimetry have been accounted for, e.g. ion recombination, electron-loss effects. A new and innovative approach has been developed in this regard, which can provide confirmation of key parameter values such as the magnetic field in the wiggler and the effective thickness of key filters. IMBL commenced operation in December 2008 with an Advanced Photon Source (APS) wiggler as the (interim) ID. A superconducting multi-pole wiggler was installed and operational in January 2013. Results are obtained for both of these IDs and useful comparisons are made. A comprehensive model of the IMBL has been developed, embodied in a new computer program named spec.exe, which has been validated against a variety of experimental measurements. Having demonstrated the reliability and robustness of the model, it is then possible to use it in a practical and predictive manner. It is hoped that spec.exe will prove to be a useful resource for synchrotron science in general, and for hard X-ray beamlines, whether they are based on bending magnets or insertion devices, in particular. In due course, it is planned to make spec.exe freely available to other synchrotron scientists.
任何同步加速器光束线的关键早期阶段都涉及详细的测试、表征和调试；对于像澳大利亚同步加速器的成像与医学光束线（IMBL）这样雄心勃勃且复杂的光束线来说尤其如此。IMBL的工作人员和专业用户一直在进行精确实验，旨在对初级多色和单色X射线束进行定量表征，特别强调摆动器插入装置（IDs）、初级狭缝系统以及任何真空和非真空过滤器。本文将描述这些研究的结果。这些结果将使IMBL和未来的其他用户受益，特别是那些对X射线束光谱（或“质量”）和通量密度的详细知识很重要的用户。这些信息对于放射治疗和放射生物学用户至关重要，他们最终需要知道（精确到优于5%）传递到其样品的X射线剂量或剂量率是多少。已经考虑了与电离室（IC）剂量测定相关的各种校正因子，例如离子复合、电子损失效应。在这方面已经开发出一种新的创新方法，它可以确认关键参数值，如摆动器中的磁场和关键过滤器的有效厚度。IMBL于2008年12月开始运行，使用先进光子源（APS）摆动器作为（临时）ID。2013年1月安装并运行了一个超导多极摆动器。获得了这两种ID的结果并进行了有益的比较。已经开发了IMBL的综合模型，体现在一个名为spec.exe的新计算机程序中，该程序已针对各种实验测量进行了验证。在证明了模型的可靠性和稳健性之后，就可以以实用和预测的方式使用它。希望spec.exe总体上能被证明是同步加速器科学的有用资源，特别是对于硬X射线光束线，无论它们是基于弯曲磁铁还是插入装置。在适当的时候，计划将spec.exe免费提供给其他同步加速器科学家。
