THE FABRICATION AND RESEARCH OF IONIZATION GAUGE BASED ON CARBON NANOTUBE CATHODE

The ionization gauge based on carbon nanotube(CNT)cathode has a broad application prospect in ultrahigh and extreme high vacuum measurement. The gauge which can measure the pressure from 10^-9 Pa to 10^-4 Pa has been developed. The gauge consists of CNT cathode, gate, anode, reflector and collector. And the electric controller is composed of high voltage power, weak current transmission and control circuits. The experimental results show that the CNT nanotube cathode prepared on the stainless steel substrate has shown a good performance. The turn on and threshold electric fields for CNT array grown on stainless steel substrate were 1.9 V/µm and 3.9 V/µm respectively. The residual current of the gauge can be reduced to 1.81×10^-9 Pa while the anode current is 42 µA.