Paper VT-TuA2
Hot Cathode Ionization Gauge Life Extension in the mTorr range by Operational Modifications

Tuesday, October 21, 2008, 2:00 pm, Room 205

Improvement of hot cathode ionization vacuum gauge lifetime in the mTorr range by reducing the sputtering of gauge electrodes onto other components of the gauge will be demonstrated. Of special interest with respect to the sputtering are deposits on the cathodes and on the feedthrough insulators which result in impaired electron emission and leakage currents, both ultimately causing gauge failure. Analytical procedures which led to the sources of the sputtered material will be described. The sputtering reduction is accomplished by reducing the potential difference through which ions are accelerated, consequently reducing the impact energy on low potential electrodes and thus reducing the yield of the sputtering. Empirical data results will be shown to agree with theory and calculations. Other changes in gauge operation to implement these modifications and other improvements to enhance high pressure gauge life will be discussed.