Berlin 2012 – wissenschaftliches Programm
VA 1.3: Vortrag
Montag, 26. März 2012, 11:00–11:20, HFT-FT 131
New Bayard-Alpert Gauge for UHV and XHV Measurement down to 5E-12 mbar — •Nikolas von Freyhold, Ivan Pongrac, Jaroslaw Iwicki, Heiko Wunderlich, and Ute Bergner — VACOM Vakuum Komponenten & Messtechnik GmbH, Jena, Germany
An increasing number of UHV applications require vacuum gauges for measuring total pressures in the range of 1E-10 mbar to 1E-11 mbar (abs.) with a certain accuracy and reproducibility. For this purpose, ionization vacuum gauges of different types are the preferred sensors. They measure ion or discharge currents that are proportional to the pressure, however nonlinearities must be taken into account towards their lower measurement limits. Bayard-Alpert hot cathode ionization gauges as well as the different cold cathode gauge types are quite dissatisfactory regarding the pressure range mentioned above, since their measurement range is limited to some E-11 mbar. Besides, the calibration of frequently used "nude" Bayard-Alpert gauges is depending strongly on the distance between sensor electrodes and the surrounding wall of the vacuum chamber.
We will present a new Bayard-Alpert hot cathode gauge optimized for UHV measurements. This gauge combines a stable calibration with successfully demonstrated improvements in terms of lower pressure limit, featuring pressure readings from 1E-2 to 5E-12 mbar. Experimental results in comparison to other Bayard-Alpert gauges and an Extractor gauge will be presented and discussed.