Micromachined Ionization Vacuum Gauge and Improve its Sensitivity with Magnetic Field

[摘要] 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.

[学科分类] 分析化学

[关键词] ionization;hot-filament ionization vacuum gauges;Bayard–Alpert vacuum gauge;micromachine;miniaturized ionization gauge