Ionization vacuum gauge with a carbon nanotube field electron emitter combined with a shield electrode

The applicability of carbon nanotubes to an electron source for a Bayard–Alpert type vacuum gauge has been investigated. Three gauge configurations are designed to optimize the gauge performance. The optimized gauge, in which an additional shield electrode is fixed on a gate electrode, exhibits good measurement of linearity between ion current and system pressure from 10−7 to 10−2 Pa. A gauge sensitivity of 0.05 Pa−1 has been achieved under 100 μA emission current for nitrogen, comparable with 0.07 Pa−1 of commercial ionization gauges.