A Bayard-Alpert vacuum gauge with microtips

With the replacement of hot filaments by field-effect microtips, many problems in Bayard-Alpert gauges caused by thermionic emission like degassing, high power consumption or mechanical weakness can be overcome. The results of the experiments made by replacing the tungsten filament by an array of microtips fabricated at LETI in a classical Bayard-Alpert gauge show, not only that microtips can be a good substitute for filaments in this application, but also that they enable one to improve some characteristics, such as the sensitivity of the gauge and the width of the working scale. Moreover, some new options like fast pulsed operation or fast security cutout are possible due to the very short time needed to stabilize the electronic emission.