Replacement monochromator cryocoolers for NE-CAT

项目摘要 东北协同接入团队(NE-CAT)运营两条波动波束线(24-ID- C和24-ID-E)。两条光束线都配备了MD2 微衍射计、低温冷却系统、样品自动安装器和像素阵列探测器。 提供对546个独立用户执行657个数据的大型用户社区的访问 2021年日历年收集旅行(3003次用户访问总数)。NE-CAT光束线收集 这些数据每年产生约180份出版物和400多份PDB存款。 两条NE-CAT光束线都使用了FMB牛津液氮制冷机来维护 它们的硅单色器晶体在90K的工作温度下的温度。 目前的低温冷却器是在最初建造光束线时安装的，现在正在 大约15岁。在他们多年的服务中，FMB牛津低温冷却器已经 一直是可靠的，只需要对其控制进行例行维护和小修 系统。为了预测它们最终的故障并减少梁的振动，我们建议 将两台制冷机更换为FMB牛津制冷机XV系统。FMB牛津制冷机 XV是经过验证的设计，将提供多年的可靠服务，同时也在改进 降低硅单色器液氮流动诱发振动的束流稳定性 水晶。

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.