Fabrication of ionization gauge with carbon nanotube cathode grown on catalytic substrates

In this work, carbon nanotubes (CNTs) cathodes were directly prepared on catalytic hastelloy substrates by chemical vapor deposition technique (CVD). The field emission properties of the CNTs cathode were estimated under an ultrahigh vacuum system with a diode structure. The results showed that the present cathode has excellent emission stability with a high current density. Subsequently, this cathode was used as an electron source of ionization gauge, and it was found that this novel cathode device demonstrated good measurement linearity in the pressure range from 10^-7 to 10^-3 Pa with a sensitivity about 0.13 Pa^-1. This gauge also has a very low consumption, which is propitious to space application.