Metrological characteristics of spherical oscillator gauge with carbon nanotube cathode

The ionization gauge with carbon nanotube (CNT) cathode has many advantages such as low power consumption, fast response, small volume and free of thermal and light radiation etc, which are favorable for the measurement of extremely high vacuum. In this work, the CNT cathodes were grown on silicon substrate by thermal chemical vapor deposition (CVD), and the metrological characteristics of spherical oscillator gauge with the resulting CNT cathode as electron source were investigated preliminarily. It was found that the spherical oscillator gauge with CNT cathode responded linearly to the pressure in the range from 8.7×10^-6 to ~0.01 Pa, and a sensitivity of ~0.003 Pa^-1 was achieved. The present ionization gauge with CNT cathode has low power consumption, which is especially suitable for space exploration applications in case the reliability and stability of the cathode can be guaranteed.