95 GHZ SPECTROMETER PULSE TIMING SYSTEM UPGRADE

95 GHZ 光谱仪脉冲计时系统升级

• 批准号: 8364020
• 负责人: CURT R DUNNAM
• 金额: $ 0.62万
• 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/8364020
• 关键词: Address; Broadsides; Computer software; Funding; Generations; Grant; Linux; Minor; Modification; National Center for Research Resources; Operating System; Output; Pattern; Physiologic pulse; Principal Investigator; Process; Relative (related person); Research; Research Infrastructure; Resolution; Resources; Source; System; Technology; Time; Uncertainty; United States National Institutes of Health; Width; Work; base; cost; instrument; millimeter; research study

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. A centerpiece instrument at ACERT is our millimeter-wave c.w./pulse spectrometer operating at 95GHz. In pulse mode, this instrument is capable of producing precisely-defined 1.2KW r.f. pulses down to 2ns widths and 1 ns absolute resolution. In its current configuration, the spectrometer utilizes a PulseBlaster ESR-300 (SpinCore Technologies, Inc.) with a proprietary high resolution broadside-parallel to time-serial converter card (ACERT-PBHR) to create an interim timing system producing r.f. control pulses with 1ns resolution. However, there are several undesirable operational tradeoffs which have been necessarily accepted in originally adapting the existing commercial timing card to our HFHF use. These drawbacks include the relatively coarse (3.2 ns) relative timing between control channels and the undesirably long delay time (16 ns) needed between programmable transitions on any one timing line. These limitations add unnecessary complexity to the pattern generation software and, to a minor extent, constrain the timing patterns actually available for the experiment. There is also an approx. 300 ps peak-to-peak timing uncertainty in the high resolution channel, which becomes consequential once other deadtime contributing factors in the spectrometer have been corrected. We are in the process of addressing these issues with a spectrometer control system upgrade incorporating a high resolution timing card (Chase Scientific DWG-1000) that outputs 12 channels with intrinsic 1ns resolution. Because the spectrometer operating system is Linux based, and suitable drivers are not yet available, some additional work will be required to incorporate the timing upgrade hardware. Presently, we are completing EIK h.v. modulator modifications which will result in a significant reduction of deadtime with the existing timing system still in place. Soon after completion and qualification of the modulator upgrades with the present timing hardware, we expect to install the new Chase Scientific timing card and modify the spectrometer control software as necessary to fully utilize its capability for additional deadtime reduction.

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 而子项目的主要调查员可能是由其他来源提供的， 包括其它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， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 ACERT的核心仪器是我们的毫米波c.w.脉冲频谱仪工作频率为95 GHz。在脉冲模式下，该仪器能够产生精确定义的1.2KW r.f.脉冲宽度低至2ns，绝对分辨率为1 ns。在其当前配置中，光谱仪利用PulseBlaster ESR-300（SpinCore Technologies，Inc.）采用专有的高分辨率宽边并行到时间串行转换器卡（ACERT-PBHR），以创建产生r.f.控制脉冲分辨率为1 ns。然而，在最初使现有商业定时卡适应我们的HFHF使用时，有几个不希望的操作权衡是必须接受的。这些缺点包括控制通道之间的相对定时相对粗糙（3.2 ns），以及任何一条定时线上的可编程转换之间所需的不期望的长延迟时间（16 ns）。这些限制给模式生成软件增加了不必要的复杂性，并且在较小程度上限制了实际可用于实验的定时模式。也有一个approx。高分辨率通道中的峰-峰时序不确定性为300 ps，一旦光谱仪中的其他死区时间影响因素得到校正，该不确定性就变得重要。 我们正在解决这些问题的过程中，光谱仪控制系统升级，包括一个高分辨率的定时卡（大通科学DWG-1000），输出12个通道与固有的1 ns分辨率。由于光谱仪操作系统是基于Linux的，并且还没有合适的驱动程序，因此需要进行一些额外的工作来整合时序升级硬件。 目前，我们正在完成EIK高压调制器的修改，这将导致死区时间的显着减少与现有的定时系统仍然存在。在使用现有定时硬件完成调制器升级并获得认证后不久，我们预计将安装新的Chase Scientific定时卡，并根据需要修改光谱仪控制软件，以充分利用其减少死区的能力。