alpha-ray vacuum gage

alpha-ray vacuum gage

[′al·fə ‚rā ′vak·yüm ‚gāj]
(engineering)
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.
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