LIQUID-PHASE ULTRAFAST ELECTRON DIFFRACTION

点击翻译按钮获取中文摘要

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).