Study of the inverted-magnetron cold emission microelectronic vacuum gauge

A microelectronic ionization vacuum gauge which is inverted-magnetron like is proposed and its operation is analysed theoretically. The device is based on the controlled motion of field emission (FE) electrons subject to crossed electric E and magnetic B fields. The electrons are shown to move on a cycloid-like closed trajectory. The sensitivity of the vacuum gauge is computed taking into account different cross sections for the ionization process. The time spent by the electron inside the device, which depends on its motion on the Z-axis, is computed assuming a uniform repelling electric field in this direction. An analysis is performed in order to find the conditions (geometrical and operational) necessary to maximize the vacuum gauge sensitivity. It is shown that loops in the electron trajectories and device dimensions should be large enough to allow the electrons to acquire enough kinetic energy for efficient ionization.