MAJOR UPGRADE OF THE X/KU BAND SPECTROMETER

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 我们10年前的2D-FT-ESR和DQC/DEER光谱仪在其使用寿命期间经历了多次修改。它一直在非常密集的使用，并已成为新概念和应用的试验场。 由于老化的组件，其中一些是买来使用的，故障变得更加频繁，它缺乏有用的自动化和其他重要功能。对于它的持续密集使用，它应该完全翻新，以满足我们新的更高标准。因此，我们计划做的是彻底升级，使其成为一个多功能的自动化机器，对新用户来说是直观的。这次大修至少包括：（a）增加一个新的现场控制器;（B）编写一个新的LabView软件界面;（c）用一个新的外差电桥取代旧的外差电桥，该电桥将有两个主通道，一个DEER通道和一个TPPI通道;（d）增加一个基于具有均匀场的介质谐振器的新探头;（e）安装一个可编程衰减器;（f）增加软件可编程接收器增益和相位;（g）实施光谱仪保护电子设备;（h）实现对信号采集的更通用的控制;（i）用基于MESFET的纳秒低瞬态开关进行升级;（j）增加场频率锁定。我们计划在所有新元件到位并经过彻底的实验室测试后，以较低的停机时间进行这些升级。

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. Our 10-years old 2D-FT-ESR and DQC/DEER spectrometer has undergone several modifications over its life-time. It has been in very intense use and has also served as a testing ground for new concepts and applications. Due to aged components, some of which were bought used, failures have became more frequent and it lacks useful automation and other important features. For its continuous intense use it should be totally renovated to meet our new higher standards. What we plan to do is thus a radical upgrade, to make of it a versatile automated machine that is intuitive for a new user. This overhaul will encompass as a minimum: (a) adding a new field controller; (b) writing a new LabView software interface, (c) replacing the old heterodyne bridge with a new one that will have two main channels, a DEER channel, and a TPPI channel; (d) adding a new probe based on a dielectric resonator with a uniform field; (e) installing a programmable attenuator; (f) adding a software programmable receiver gain and phase; (g) implementing spectrometer protect electronics; (h) achieving more versatile control over signal acquisition; (i) upgrading with MESFET based nanosecond low-transient switches; (j) adding field-frequency lock. We plan to make these upgrade with low down-time when all new elements are in place and thoroughly bench-tested.