CONTROLLED-TEMPERATURE INSERT FOR 95 GHZ CW/PULSE SPECTROMETRY

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 而子项目的主要调查员可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 ACERT计划在2007年8月下旬安装一个低温有限公司的9 T无低温磁体和低温插入件。此时间表表示从原始安装日期延迟3个月。对于即将在我们现有的6 T Oxford磁体中对蛋白质系统进行的步进频率95 GHz DEER实验，我们因此对我们早期的JOMO-I温度控制系统进行了重要的中期升级规范和设计。我们目前正在组装的温度控制插件（CTI）升级包括增加一个闭环气体预热器部分，在现有的“ambienstat”插件结构内建造一个低时间恒定温度控制加热器，以及对一个或两个真空保持温暖的孔“O”形环密封进行温度监测。现有的Lakeshore 331型温度控制器，其输入来自样品处的适当传感器，将被保留作为主要的温度调节系统。预计温度控制在0.1 <$K稳定性下低至100 <$K。 已获得用于临时CTI升级的所有组件，并已修改插件结构，以在靠近样品的位置（7 cm）接受加热器/电枢组件。目前正在建造一个机架底盘，该机架底盘带有前面板Omega控制器/监视器和用于预热器调节和O形环密封温度监视（以及可选的控制）的加热器功率驱动电路。我们打算在几周内完成机架式CTI预热器控制系统的构建和调试，届时控制器将与修改后的环境恒温器和低温恒温器O形环密封监测器一起安装在95 GHz磁体中。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. ACERT is scheduled for installation of a Cryogenic, Ltd. 9T cryogen-free magnet and low-temperature insert in late August, 2007. This schedule represents a 3-month delay from the original installation date. For impending step-frequency 95 GHz DEER experiments on protein systems in our existing 6T Oxford magnet, we have therefore proceeded with specification and design of a significant interim upgrade to our earlier JOMO-I temperature control system. The Controlled Temperature Insert (CTI) upgrade that we are presently assembling consists of an added closed-loop gas pre-heater section, construction of a low time-constant temperature control heater within the existing "ambienstat" insert structure and temperature monitoring of one or both of the vacuum-retaining warm bore "O"-ring seals. The existing Lakeshore model 331 temperature controller, with input from an appropriate sensor at the sample, will be retained as the primary temperature regulating system. Temperature control down to 100¿K at 0.1¿K stability is expected. All components for the interim CTI upgrade have been acquired, and the insert structure has been modified to accept a heater/armature assembly in a position of close proximity (7 cm) to the sample. A rack chassis with front panel Omega controller/monitors and heater power driver circuitry for preheater regulation and O-ring seals temperature monitoring (and, optionally, control) is currently under construction. We intend to complete construction and debug of the rackmount CTI preheater control system within a few weeks, at which time the controller will be installed in the 95 GHz magnet in concert with the revised ambienstat and cryostat O-ring seal monitors.