Numerical simulation of the performance of the ASDEX pressure gauge

Abstract The normalised output Ii/(Ie-Ii) and sensitivity of the ASDEX pressure gauge are numerically simulated in this paper. The effects of the electrode spacing, width of grid slit and electrode voltage on the sensitivity of the ASDEX gauge are analyzed respectively, and the orthogonal analysis method is applied to optimize the structural and electrical parameters of the ASDEX pressure gauge. According to the simulation result, the sensitivity of the optimized gauge is increased to 0.01138Pa−1 without magnetic field. The motion trajectories of emitted electrons and sensitivity are simulated when the magnetic induction intensity is in the range of 0∼1T. The studies have demonstrated that the magnetic field inhibited the motion of emission electrons in the direction perpendicular to the base plate, increasing the probability of the electrons reaching the effective ionization volume and extending the electron path length due to the helical trajectories. When the magnetic induction intensity increased from 0 to 1T, the sensitivity of the gauge increases from 0.01138 Pa-1 to 0.149 Pa-1.