Gicala Patrick, Petruk Ariel A, Rivas Nicolás, Netzke Sam, Pichugin Kostyantyn, Sciaini Germán
The Ultrafast Electron Imaging Laboratory, Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
Rev Sci Instrum. 2021 Oct 1;92(10):103303. doi: 10.1063/5.0058939.
Highly energetic ultrashort electron bunches have the potential to reveal the ultrafast structural dynamics in relatively thicker in-liquid samples. However, direct current voltages higher than 100 kV are exponentially difficult to attain as surface and vacuum breakdown become an important problem as the electric field increases. One of the most demanding components in the design of a high-energy electrostatic ultrafast electron source is the high voltage feedthrough (HVFT), which must keep the electron gun from discharging against ground. Electrical discharges can cause irreversible component damage, while voltage instabilities render the instrument inoperative. We report the design, manufacturing, and conditioning process for a new HVFT that utilizes ultra-high molecular weight polyethylene as the insulating material. Our HVFT is highly customizable and inexpensive and has proven to be effective in high voltage applications. After a couple of weeks of gas and voltage conditioning, we achieved a maximum voltage of 180 kV with a progressively improved vacuum level of 1.8 × 10 Torr.
高能量超短电子束有潜力揭示相对较厚液体样品中的超快结构动力学。然而，随着电场增加，表面和真空击穿成为一个重要问题，要获得高于100 kV的直流电压变得越来越困难。高能静电超快电子源设计中最苛刻的部件之一是高压馈通（HVFT），它必须防止电子枪对地放电。放电会导致部件不可逆转的损坏，而电压不稳定会使仪器无法运行。我们报告了一种新型高压馈通的设计、制造和调节过程，该高压馈通使用超高分子量聚乙烯作为绝缘材料。我们的高压馈通具有高度可定制性且价格低廉，已证明在高压应用中有效。经过几周的气体和电压调节，我们实现了180 kV的最大电压，真空度逐步提高到1.8×10托。
