[William D. Coolidge, U.S. physicist and chemist, 1873-1975]
A kind of hot-cathode tube that is so highly exhausted that the residual gas plays no part in the production of the cathode stream, and that is regulated by variable heating of the cathode filament.
Taber’s Cyclopedic Medical Dictionary Online + Mobile powered by Unbound Medicine. Find 65,000 medical and nursing definitions. Download to iPhone, iPad, and Android. Learn more.