Micromachined Ionization Vacuum Gauge and Improve its Sensitivity with Magnetic Field

Abstract

One of the most efficient methods for Ultra High Vacuum (UHV) measurement is the
use of hot-filament ionization gauge which has been employed for several decades
and can quantify pressures up to 〖10〗^(-12) torr. Large volume and high-power
consumption are main drawbacks of this gauge. In this paper, a MEMS type ionization
vacuum gauge has been introduced which occupies a volume of 3mm×1.5mm×1.5mm
and is manufacturable with micromachines technology. Also, it operates based on gas
ionization. In addition of low volume, the proposed structure has the advantages of
low power consumption, low price and fast response time. With the help of COMSOL
and MATLAB, a method has been proposed which helps us to obtain average length
of movement for electron 1, average energy of the electrons, electron speed, elastic
and ionization collision frequency and sensitivity coefficient S. Simulation results have
been compared with theoretical analytic results in which there is good conformity
between these results. Also, by means of the presented method in this article, the
physical characteristics of the gauge can be optimized to achieve better performance.
For the proposed scheme by introducing the magnetic field as the novel idea, the
sensitivity coefficient has been enhanced up to 60% in comparison with similar
structures.