MAJOR UPGRADE OF THE X/KU BAND SPECTROMETER

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。 我们已有10年历史的2D-FT-ESR和DQC/Deer光谱仪在其使用寿命内经历了几次改进。它得到了非常广泛的使用，也成为了新概念和新应用的试验场。由于老旧的部件，其中一些是买来的二手部件，故障变得更加频繁，而且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，它应该进行彻底翻新，以满足我们新的更高标准。因此，我们计划进行彻底的升级，使其成为一台多功能的自动化机器，对新用户来说是直观的。这次大修将至少包括：(A)增加一个新的现场控制器；(B)编写一个新的LabVIEW软件接口；(C)用一个新的外差桥取代旧的外差桥，它将有两个主通道，一个鹿通道和一个TPPI通道；(D)增加一个基于均匀场介质谐振器的新探头；(E)安装一个可编程衰减器；(F)增加一个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)对信号采集实现更多功能的控制；(I)使用基于MESFET的纳秒低瞬变开关进行升级；(J)增加场频锁定。我们计划在所有新元素都到位并进行彻底的台式测试后，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.