ヌード型B-A真空計の感度係数の取り付け管径依存性に関するシミュレーション

抄録

Sensitivity coefficient of a nude-type Bayard-Alpert gauge depends on the diameter of an envelope. In our measurement on four gauges, sensitivity coefficients of three gauges in small envelopes (inner diameter of 35, 38 mm) were higher by 2040% than those in large envelopes (54, 70 mm) for nitrogen in high vacuum 10^-4 Pa. One gauge showed small dependence of the coefficient on the diameter. In order to discuss these experimental results, an electric potential distribution and an electron trajectory inside the envelope were calculated using a super-computer. And a sensitivity coefficient was estimated using the potential distribution and the electron trajectory. The estimation showed that the coefficient of a gauge with a wide gap (3 mm) between a grid and a filament has the same dependence on the diameter as those of three gauges and the coefficient of a gauge with a narrow gap (1 mm) has small dependence on the diameter. Large envelope gives small dependence of the coefficient on the gap.