alpha-ray vacuum gage
alpha-ray vacuum gage[′al·fə ‚rā ′vak·yüm ‚gāj]
An ionization gage in which the ionization is produced by alpha particles emitted by a radioactive source, instead of by electrons emitted from a hot filament; used chiefly for pressures from 10−3to 10 torrs. Also known as alphatron.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.