Performance of a Modified Buried Collector Gauge

The performance of a modified buried collector gauge was determined over a (helium) pressure range 10−13–10−4 Torr. Optimum operating parameters were empirically chosen. With 5.0-mA emission current and 100-V grid to filament potential, the x-ray photoelectron current of the gauge was estimated to be 5.2×10−13 A. By subtracting the measured background current, linear response was obtained between 6×10−13 and 3×10−4 Torr (He) with a gauge sensitivity of 0.015 A/Torr (He). Variations of gauge sensitivity as a function of filament geometry are discussed.