A Study Of Carbon Nanotube-Based Ionization Gauges |
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| In-Mook Choi, Sam-Yong Woo, and Boo-Shik Kim |
- Abstract:
- Low-pressure detection technology utilizing the field emission of carbon nanotubes (CNTs) is introduced. The use of an ionization gauge is a viable alternative method for measurements at low pressure levels, but their use is limited by such factors as the bulky size, high power consumption, x-ray radiation, heat and light generation, and outgassing associated with this type of gauge. To overcome the limitations of conventional ionization gauges, CNTs have been proposed as an electron source. The performance of a CNTbased low-pressure gauge, including the sensitivity, measurement range, and linearity, has been improved greatly by changing the structure of the electrodes. The sensor showed a linear pressure measurement range from 5·10-7 to 10-2 Torr. Furthermore, the service life of the CNT emitter could be extended greatly by modulating the pulse of the voltage with a 20 % duty ratio. However, the service life of the CNT-based sensor is especially short, particularly when it is used at relatively high pressure levels. Accordingly, a CNT array directly grown by thermal Chemical Vapor Deposition is proposed. An integrated emitter directly grown with a catalyst metal can provide a low turn-on field by reducing the distance between the grid and CNTs while providing a longer emission lifetime. The characteristics of the directly grown CNT array and the screen-printed CNT array are compared for possible use with a practical pressure sensor.
- Keywords:
- field emission, carbon nanotube, ionization, pressure
- Download:
- IMEKO-TC16-2007-037u.pdf
- DOI:
- -
- Event details
- IMEKO TC:
- TC16
- Event name:
- Cultivating Metrological Knowledge
- Title:
- 3rd Conference on Pressure Measurement (together with 20th TC3 Conference on Measurement of Force, Mass and Torque & 1st TC22 Conference on Vibration Measurement)
- Place:
- Merida, MEXICO
- Time:
- 27 November 2007 - 01 December 2007