LIQUID-PHASE ULTRAFAST ELECTRON DIFFRACTION

NSERC-RTI的资金支持对于升级我们自制的高能超快电子衍射仪(UED)至关重要，这里指的是滑铁卢-UED。升级涉及购买高精度负极性150千伏高压电源(HVPS)和真空系统，这些都是在内部制造两级直流(DC)线性加速器和泄漏检查站附件所必需的。两级直流线性加速器是确保稳定的300千伏运行条件的关键，同时确保我们实验室空间的辐射水平不超过平均本底水平。必须使用高能(&gt；250kev)电子才能穿越亚微米厚的液体层，而不会面临信息损失。我们已经开发和测试了专利的纳米流体电池(NFC)系统，该系统将提供所需的300 nm厚的液体层(夹在25 nm厚的透明窗口之间)，以成功进行液体UED测量。为了强调这次升级及其科学影响的重要性，滑铁卢UED(即300 keV超短电子爆发)和我们的专利NFC系统的组合将使我们能够首次在实验室环境中研究液体超快结构现象，并使我们与斯坦福直线加速器中心(SLAC-UED)的兆电子伏特UED设施形成直接竞争。SLAC-UED是目前世界上唯一有能力进行液体UED实验的设施。因此，我的实验室将是加拿大唯一拥有进行液态UED所需基础设施的实验室，这项请求将启动其向高能液态UED设施的转变，加拿大研究人员将通过与SLAC-UED实施的管理计划类似的管理计划向加拿大研究人员提供该设施。在SLAC-UED，在评估和批准研究方案后，向用户免费分配射束时间。滑铁卢-UED和该仪器支持的研究计划--液态UED，是HQP最完整的培训计划之一的一部分(详情见建议)。仅从我的团队来看，一旦我的实验室作为加拿大设施开放(大约2023年年中)，平均每个学位周期将有2个PDF、5个博士和2个MSCs使用滑铁卢-UED以及其他几个外部用户。

NSERC-RTI funding support is critical to upgrade our homemade high-energy ultrafast electron diffractometer (UED), herein referred to as Waterloo-UED. The upgrade involves the purchase of a high precision negative polarity 150-kV high voltage power supply (HVPS) and a vacuum system, which are necessary to fabricate a two-stage direct current (DC) linear accelerator and a leak check station attachment in house. The two-stage DC linear accelerator is crucial to enable stable 300-kV operation conditions while ensuring that the level of radiation in our laboratory space does not exceed the average background level. High-energy (>250 keV) electrons are a must in order to traverse a sub-micron thick liquid layer without facing loss of information. We have already developed and tested the proprietary nanofluidic cell (NFC) system that will confer the required 300-nm thick liquid layer (sandwiched between 25-nm thick transparent windows) to succeed with liquid-phase UED measurements.  To stress the importance of this upgrade and its scientific impact, the combination of Waterloo-UED (i.e., 300-keV ultrashort electron bursts) and our proprietary NFC system will enable the study of liquid-phase ultrafast structural phenomena in a laboratory setting for the very first time and place us in direct competition with the mega electron volt UED facility of the Stanford Linear Accelerator Center (SLAC-UED). SLAC-UED is currently the only facility in the world with capabilities to carry out liquid-phase UED experiments. Thus, my laboratory will be the only one in Canada with the required infrastructure to perform liquid-phase UED and this request will initiate its transformation into a high-energy liquid-phase UED facility that will be made available to Canadian researchers via a similar management scheme to the one implemented at SLAC-UED. At SLAC-UED beam time is assigned to users at no cost after the evaluation and approval of research proposals. Waterloo-UED and the research program that this instrument supports, liquid-phase UED, are part of one of the most complete training programs for HQP (see proposal for details). From my group alone, an average of 2 PDFs, 5 PhDs, and 2 MScs per degree cycle will utilize Waterloo-UED in addition to several other external users once my laboratory opens as a Canadian facility (ca. mid-2023).