95GHZ CW ESR SPECTROMETER DEVELOPMENT

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 在广泛开发95 GHz高功率脉冲工作的同时，我们还利用了我们95 GHz光谱仪的连续波能力。连续波工作的最佳工作参数，特别是在谐振器耦合和品质因数的选择上，与脉冲工作有很大的不同，因此我们在连续波模式下工作时在光谱仪中加入了重要的补充设备。然而，与此同时，我们希望确保从脉冲到连续波的快速转换将是可行的。在完成了大量的设计和开发工作后，我们实现了这一设计目标。执行CW工作所需的其他设备包括：磁场调制放大器、分光计上的锁定探测器，用于将CW频谱从磁场调制中去卷积，以及专门设计的场调制线圈，用于减少这项工作所需高磁场中的微音学。重要的开发工作还使我们能够建立有用的快速调谐协议，该协议基于相移毫米波入射到谐振器，以区分不需要的桥内反射和谐振器响应。我们正在探索在170/240 GHz桥上实施这些改进的调谐技术的方法。最近的工作还侧重于改进温度控制和实施单晶旋转能力，作为Acert中心多频能力的一部分。我们设置的另一个优点是，可以在不干扰样品的情况下影响从脉冲到连续工作的转换，这为研究人员提供了非常有用的灵活性。

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. In parallel with our extensive development of high power pulse work at 95GHz, we have also exploited the cw capabilities of our 95GHz spectrometer. The optimum operating parameters for cw operation, particularly in the choice of the resonator coupling and quality factor, are sufficiently different from pulsed work that we have incorporated significant supplemental equipment into the spectrometer when operating in cw mode. At the same time, however, we wanted to ensure that rapid conversion from pulse to cw operation would be feasible. After a significant amount of design and development work was completed, we achieved this design goal. Additional equipment necessary for performing cw work includes: a magnetic field modulation amplifier, lock-in detectors on the spectrometer in-phase and quadrature channels to deconvolve the cw spectrum from the magnetic field modulation, and a specially designed field modulation coil designed to reduce microphonics in the high magnetic fields necessary for this work. Significant development work has also allowed us to establish useful, rapid tuning protocols based on phase shifting the millimeter waves incident on the resonator to distinguish unwanted intra-bridge reflections from the resonator response. We are exploring ways to implement these improved tuning techniques on our 170/240GHz bridge. Recent work has also focused on improved temperature control and implementing single crystal rotation capability as part of the multifrequency capability of the ACERT center. Another advantage of our setup is that the conversion from pulse to cw operation may be affected without disturbing the sample, which provides a very useful degree of flexibility to the investigator.