Fast Access at Beamline ID19: Microtomography

The experimental programme at beamline ID19 underwent tremendous changes in the more than 20 years of operation: starting from Bragg diffraction topography (already with a substantial contribution of in situ experiments), the beamline pioneered hard X-ray phase contrast microtomography in routine user application, later coupled with polychromatic illumination to exploit hard X-rays up to 250 keV as well as short exposure times. Here, we propose an access route for routine microtomography which is fast, i.e. can be made available on short terms, and requires minimal overheads for the beamline staff. The basic idea is to deploy the robotic sample changer of the beamline which has already proven to be a useful tool during the pandemic where users remotely scanned and changed samples. It can be easily installed, with samples pre-mounted from the users loaded and made available in non-used evening and night shifts in a remote manner exactly like it was done during the pandemic.

ID19光束线（beamline ID19）的实验项目在二十余年的运行历程中历经巨变：最初以布拉格衍射形貌术（Bragg diffraction topography）为起点，彼时已包含大量原位实验内容；该光束线率先将硬X射线相衬显微断层扫描（hard X-ray phase contrast microtomography）应用于常规用户实验，后续又搭配多色照明（polychromatic illumination）技术，可覆盖最高250千电子伏（keV）的硬X射线波段，并支持短曝光时长。在此基础上，我们提出一种面向常规显微断层扫描的实验通道方案，其优势在于快速便捷——可在短周期内投入使用，且对光束线运维人员的额外开销极低。该方案的核心思路是启用光束线现有的自动样品更换装置（robotic sample changer）；该装置在新冠疫情期间已被证实为高效工具，当时用户可通过远程方式完成样品扫描与更换操作。该装置部署简便，用户可预先完成样品装载，随后即可在闲置的晚间及夜班时段通过远程方式开展实验，操作流程与疫情期间完全一致。