Replacement monochromator cryocoolers for NE-CAT

项目概要 东北协作访问团队 (NE-CAT) 运营着两条波荡器光束线 (24-ID- C 和 24-ID-E）在高级光子源。两条光束线均配备 MD2 微衍射仪、低温冷却系统、样品自动安装机和像素阵列探测器。 向大型用户社区提供访问权限，其中 546 个唯一用户执行 657 个数据 2021 日历年的收集行程（用户总访问量为 3003 次）。 NE-CAT 光束线收集 数据每年产生大约 180 篇出版物和 400 多个 PDB 存款。 两条 NE-CAT 光束线均采用 FMB Oxford 液氮制冷机来维持 他们的硅单色仪晶体在 90 K 的工作温度下的温度。 当前的低温冷却器是在最初建造光束线时安装的，现在是 大约15岁。经过多年的使用，FMB Oxford 制冷机已 可靠，只需要对其控制进行日常维护和小修 系统。预测它们的最终故障并减少梁振动，我们建议 将两个制冷机替换为 FMB Oxford Cryocooler XV 系统。 FMB 牛津制冷机 XV 是一种经过验证的设计，可提供多年可靠的服务，同时还改进 通过减少液氮流引起的硅单色仪振动来提高光束稳定性 晶体。

Project Summary The Northeast Collaborative Access Team (NE-CAT) operates two undulator beamlines (24-ID- C and 24-ID-E) at the Advanced Photon Source. Both beamlines are equipped with MD2 microdiffractometers, cryocooling systems, sample automounters, and pixel array detectors. Access is provided to a large user community with 546 unique users performing 657 data collection trips in calendar year 2021 (3003 total user visits). The NE-CAT beamlines collect data resulting in approximately 180 publications and over 400 PDB deposits per year. Both NE-CAT beamlines employ FMB Oxford liquid nitrogen cryocoolers to maintain the temperature of their silicon monochromator crystals at an operational temperature of 90 K. The current cryocoolers were installed when the beamlines were originally constructed and are now approximately 15 years old. Over their many years of service, the FMB Oxford cryocoolers have been dependable and only required routine maintenance and minor repairs to their control systems. Anticipating their eventual failure and to reduce beam vibrations, we propose to replace both cryocoolers with FMB Oxford Cryocooler XV systems. The FMB Oxford Cryocooler XV is a proven design that will provide many years of dependable service while also improving beam stability by reducing liquid nitrogen flow-induced vibrations of the silicon monochromator crystals.