95GHZ SPECTROMETER PULSED EXTENDED-INTERACTION KLYSTRON

95GHZ 光谱仪脉冲扩展交互速调管

• 批准号: 7956745
• 负责人: CURT R DUNNAM
• 金额: $ 0.3万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2010-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7956745
• 关键词: Boxing; Canada; Characteristics; Computer Retrieval of Information on Scientific Projects Database; Electrodes; Electron Spin Resonance Spectroscopy; Exhibits; Failure; Funding; Goals; Grant; Institution; Manufacturer Name; Measurement; Measures; Modification; Normal Range; Output; Performance; Physiologic pulse; Research; Research Personnel; Resources; Risk; Source; Technology; Testing; Time; Tube; United States National Institutes of Health; improved; programs; repaired

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. 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.

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。 随着我们最近完成对集成95 GHz频谱仪扩展相互作用速调管（EIK）脉冲调制器的升级（详见子项目0252），ACERT已经进入了一个显著改进的高功率脉冲HF ESR光谱的新时代。初始高功率射频在完整的光谱仪中的测试表明，EIK管偏置和选通束“开启”时间现在可以被调节，以用于基本上不可测量的功率下降，时间间隔高达大约800 ns。然而，从我们最初的升级后经验调整和观察中已经变得明显的是，我们在高功率脉冲下的EIK偏置要求与制造商的（CPI，Inc.，加拿大）规格说明。 因此，我们启动了一项适度的计划，以更完整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1秒的光束“开启”时间内（当时固定）表现出显著的功率下降。在饱和模式下，测量到的下降是初始输出功率的21%的容许值，但是不饱和下降的显著测量表明在射束脉冲间隔上的功率损失为78%的极高值。在并入调制器升级和修复由于组件故障引起的调制器聚焦电极偏置电源偏移之后，观察到大致相同的下降值。然而，随着高压开关电源调整到之前的3 KV限值以上，观察到EIK功率下降特性急剧下降。这一观察结果表明，最佳r.f.在射束“开启”时间期间的功率提取可以比CPI提供的0 - 20 V规范更正。我们将在短期内研究最佳的即时偏置调整，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。这些研究将在操作参数条件的正常范围内进行。从长远来看，我们将移除调制器盒，目标是确定对调制器进行必要的修改，以完全消除下垂效应。