95GHZ SPECTROMETER PULSED EXTENDED-INTERACTION KLYSTRON

95GHZ 光谱仪脉冲扩展交互速调管

• 批准号: 8364055
• 负责人: CURT R DUNNAM
• 金额: $ 0.26万
• 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/8364055
• 关键词: Boxing; Canada; Characteristics; Electrodes; Electron Spin Resonance Spectroscopy; Exhibits; Failure; Funding; Goals; Grant; Manufacturer Name; Measurement; Measures; Modification; National Center for Research Resources; Normal Range; Output; Performance; Physiologic pulse; Principal Investigator; Research; Research Infrastructure; Resources; Risk; Source; Technology; Testing; Time; Tube; United States National Institutes of Health; cost; improved; programs; repaired

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. With completion of our recent upgrades to the integrated 95 GHz spectrometer extended-interaction klystron (EIK) pulse modulator, detailed in Subproject 0252, ACERT has entered a new era of significantly improved high-power pulse HF ESR spectroscopy. Initial high-power r.f. tests in the complete spectrometer indicate that the EIK tube bias and gated beam "on" time can now be adjusted for essentially unmeasurable power droop for intervals up to approximately 800ns. It has become evident from our initial post-upgrade empirical adjustments and observations, however, that our EIK biasing requirements under high-power pulsing are somewhat different than the manufacturer's (CPI, Inc., Canada) specifications indicate. Therefore, we have initiated a modest program for achieving a more complete picture of tube performance under different bias and drive conditions. Prior to the recent upgrade program, we had found that the EIK exhibited significant power droop during a (at that time fixed) 1¿s beam "on" time. In saturated mode the droop was measured to be a tolerable value of 21% of initial output power but the telling measurement of unsaturated droop indicated an extremely high value of 78% power loss over the beam pulse interval. Following incorporation of the modulator upgrades and repair of a modulator focus electrode bias supply offset due to component failure, approximately the same droop values were observed. However, a dramatic reduction of the EIK power droop characteristic was observed with adjustment of the h.v. switch supply above the previous 3KV limit. This observation indicates that the required focus electrode potential for optimum r.f. power extraction during the beam "on" time may be more positive than the 0¿20V specification supplied by CPI. We will in the near term investigate the best immediate bias adjustment for simultaneously minimizing power droop and overvoltage risk the modulator's expensive h.v. switch. These studies will be performed over the normal range of operating parametric conditions. In the long-term we will remove the modulator box with the goal of determining necessary modifications to the modulator to eliminate the droop effect entirely.

该子项目是利用资源的众多研究子项目之一 由 NIH/NCRR 资助的中心拨款提供 该子项目的主要支持。 并且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 来源的子项目可能列出的总成本。 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。 随着我们最近对集成 95 GHz 光谱仪扩展交互速调管 (EIK) 脉冲调制器的升级（详见子项目 0252），ACERT 已进入显着改进的高功率脉冲 HF ESR 光谱的新时代。完整的光谱仪中表明，现在可以调整 EIK 管偏置和门控光束“开启”时间，以实现基本上不可测量的功率下降，间隔时间可达然而，从我们最初的升级后经验调整和观察来看，我们在高功率脉冲下的 EIK 偏置要求与制造商（加拿大 CPI 公司）指示的规格有所不同。已经启动了一项适度的计划，以更全面地了解不同偏置和驱动条件下的电子管性能。 在最近的升级计划之前，我们发现 EIK 在（当时固定的）1¿在饱和模式下，测得的下降值为初始输出功率的 21%，但非饱和下降的明显测量结果表明，在随后的光束脉冲间隔内，功率损耗极高。结合调制器升级和由于组件故障而修复调制器聚焦电极偏置电源偏移，观察到大致相同的下降值，但是，通过调整 EIK 功率下降特性，观察到显着降低。高压开关电源高于之前的 3KV 限制，这一观察结果表明，在光束“开启”时间内，所需的聚焦电极电势可能比 CPI 提供的 0¿20V 规格更高。研究最佳的即时偏置调整，以同时最大限度地减少调制器昂贵的高压开关的功率下降和过压风险。从长远来看，我们将在正常的工作参数条件范围内进行这些研究。调制器盒的目标是确定对调制器进行必要的修改，以完全消除下降效应。