A NEW SAMPLE CHAMBER WITH TEMPERATURE AND HUMIDITY CONTROL FOR LIPID AND FIBER S

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 许多研究脂质、脂质-蛋白质相互作用和生物纤维的X射线实验都要求能够准确地监测和控制样品的温度和水合状态。在这些实验中，需要在各种不同的温度/水合条件下进行测量。在BL4-2上，一次测量的典型曝光时间从几秒到最多几分钟不等，因此，为了有效利用实验时间，样品环境的控制不仅要准确，而且要相当快。为满足这些要求，设计了一种新的样品室，将Peltier元件与PID控制电子设备结合在一起，使我们能够快速改变并可靠地控制密封室内的温度和湿度条件。电离室安装在标准测角仪头上，通常由安装在BL4-2标准电动样品台上的Huber测角器固定。有了这一点，我们就可以很容易地在实验中改变样品相对于光束的倾斜角，这是在平板衬底上对准样品进行实验所必需的。上位机通过串口(RS232)与控制电子设备通信，所有控制参数均可远程设置。这种串口通信将允许我们在不久的将来将燃烧室控制集成到DCS/BLU-Ice束流线软件中。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Many x-ray experiments studying lipids, lipid-protein interactions and biological fibers require the ability to accurately monitor and control the temperature and hydration state of the specimen. In these experiments the measurements need to be done under a variety of different temperature/hydration conditions. On BL4-2 the typical exposure time for one measurement ranges from a few seconds to at most a few minutes, thus in order to make efficient use of the experimental time, the control of the sample environment should not only be accurate but also be reasonably fast. A new sample chamber has been designed to meet these requirements, incorporating Peltier elements together with PID control electronics, and allows us to quickly change and reliably control the temperature and humidity conditions inside the sealed chamber. The chamber is mounted on a standard goniometer head, which is usually held by a Huber goniostat mounted on the standard motorized sample stage at BL4-2. With this we can easily change the tilt angle of the sample with respect to the beam during the experiment which is necessary for experiments on aligned samples supported on a flat substrate. A PC is used to communicate with the control electronics through a serial port (RS232) and all the control parameters can be set remotely. This serial port communication will allow us in near future to integrate the chamber control into the DCS/Blu-Ice beam line software.