AUTOMATIC FREQUENCY CONTROL (AFC) SYSTEM FOR HIGH-FIELD BRIDGE

高场电桥自动频率控制 (AFC) 系统

• 批准号: 8363969
• 负责人: CURT R DUNNAM
• 金额: $ 0.05万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8363969
• 关键词: Confusion; Development; Frequencies; Funding; Goals; Grant; Measurement; Mechanics; Mind; National Center for Research Resources; Positioning Attribute; Principal Investigator; Relative (related person); Research; Research Infrastructure; Resources; Sampling; Schedule; Series; Source; System; Technology; Testing; United States National Institutes of Health; Variant; arm; cost; design; experience; improved; instrument; microwave electromagnetic radiation; millimeter; research study; vibration

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 facilities presently include a 170/240GHz quasioptical-bridge spectrometer for c.w. EPR studies. During the past year, the spectrometer bridge has been substantially upgraded, e.g., with replacement of the c.w. millimeter-wave sources and installation of a newly-designed reference arm. Additionally, the spectrometer resonator has benefited from a series of mechanical improvements which have significantly improved vibration isolation and tuning accuracy. Our goal in pursuing the fabrication and implementation of these items is to create an instrument of exceptional capability while maintaining relative ease of use for less-experienced operators. With that objective in mind, we intend to continue our development of an automatic frequency control (AFC) system for the 170/240GHz c.w. spectrometer suitable for use with either of the recently-acquired millimeter-wave sources. In common with familiar AFC systems found in conventional c.w. microwave EPR instruments, our proposed high-field AFC systems will provide conventional source frequency-tracking capability, thereby eliminating detrimental effects of resonator or source frequency drift during the course of an experiment. In our conceptual design, it will also be possible to configure the AFC system in a way which simplifies adjustment of the Fabry-Perot resonator by allowing adjustment of sample position without the potential for operator confusion due to detuning effects caused by corresponding variation in the sample's dielectric loading. Preliminary design measurements and studies of the AFC loop have been made and a conceptual design completed. We have tentatively scheduled construction, test and final implementation of this spectrometer upgrade for later this year.

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 子项目的主要研究者可能是由其他来源提供的， 包括其他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， NCRR赠款不直接向子项目或子项目工作人员提供资金。 ACERT设施目前包括一个170/240 GHz的准光桥光谱仪的c.w. EPR研究。在过去的一年中，光谱仪桥得到了大幅升级，例如，更换c.w.此外，光谱仪谐振器还受益于一系列机械改进，这些改进显著提高了振动隔离和调谐精度。我们追求这些项目的制造和实施的目标是创造一种具有卓越能力的仪器，同时保持相对易用性，以供经验不足的操作员使用。 考虑到这一目标，我们打算继续为170/240 GHz连续波开发自动频率控制（AFC）系统。光谱仪适合与最近获得的毫米波源中的任一个一起使用。与传统c.w.中常见的AFC系统一样，与微波EPR仪器相比，我们提出的高场AFC系统将提供传统的源频率跟踪能力，从而消除实验过程中谐振器或源频率漂移的不利影响。在我们的概念设计中，还可以以这样的方式配置AFC系统，该方式通过允许调整样品位置而简化法布里-珀罗谐振器的调整，而不会由于样品的介电负载的相应变化引起的失谐效应而导致操作员混淆。 已经对AFC环路进行了初步设计测量和研究，并完成了概念设计。我们已暂定今年晚些时候建造、测试和最终实施这一光谱仪升级。