Doppler electron velocimetry : notes on creating a practical tool.

[摘要] The Doppler electron velocimeter (DEV) has been shown to be theoretically possible. This report attempts to answer the next logical question: Is it a practical instrument? The answer hinges upon whether enough electrons are available to create a time-varying Doppler current to be measured by a detector with enough sensitivity and bandwidth. The answer to both of these questions is a qualified yes. A target Doppler frequency of 1 MHz was set as a minimum rate of interest. At this target a theoretical beam current signal-to-noise ratio of 25-to-1 is shown for existing electron holography equipment. A detector is also demonstrated with a bandwidth of 1-MHz at a current of 10 pA. Additionally, a Linnik-type interferometer that would increase the available beam current is shown that would offer a more flexible arrangement for Doppler electron measurements over the traditional biprism.

[发布日期] 2008-11-01

[学科分类] 工程和技术（综合）

[关键词] DOPPLER EFFECT;VELOCIMETERS;ELECTRON BEAMS;BEAM CURRENTS;INTERFEROMETERS;SENSITIVITY;SIGNAL-TO-NOISE RATIO;DESIGN Doppler radar.;ELECTRON BEAMS -MEASUREMENT;Laser Doppler velocimeter.