Pressure Measurements Below 10-10 Torr with Bayard-Alpert and Magnetron Gauges

Journal Article · Tue Jan 01 04:00:00 EST 1963 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.1718651· OSTI ID:4636383

Torney, Franklin L.; Feakes, Frank

Below 1 x 10^-10 Torr, pressure measurement by means of Bayard- Alpert type ion gages is complicated by the existence of a current associated with soft x rays.'' The precise measurement of a true ion current requires precise determination of the so-called x-ray limit of each gage. The present work describes the use of a BayardAlpert gage containing a modulating electrode (after the design of Redhead) to measure pressures below 10^-10 Torr. Magnetron-type gages, which do not have x-ray limitations, were then compared directly with the Bayard-Alpert gages. In addition, gage comparisons were carried out in a dynamic system involving pressure ratios across a capillary. Both series of experiments showed that the output current of the magnetron gage was a power function (exponent 1.8) below approximately 2 x 10^-10 Torr (N₂). In the latter work it was possible to make measurements to below 1 x 10 Torr N₂ equivalent.

• Research Organization: National Research Corp., Cambridge, Mass.
• Sponsoring Organization: USDOE
• NSA Number: NSA-17-037415
• OSTI ID: 4636383
• Journal Information: Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 9 Vol. 34; ISSN 0034-6748; ISSN RSINAK
• Publisher: American Institute of Physics (AIP)
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
BAYARD-ALPERT GAGE
CAPILLARIES
ELECTRODES
ELECTRON TUBES
ION BEAMS
IONIZATION
MAGNETRONS
MEASURED VALUES
MODULATION
POWER
PRESSURE
VACUUM
X RADIATION