dispenser cathode

dispenser cathode

[də′spen·sər ‚kath‚ōd]
(electronics)
An electron tube cathode having provisions for continuously replacing evaporated electron-emitting material.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
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References in periodicals archive ?
the dispenser cathode is operated at temperatures below 1000[degrees]C.
Watkins-Johnson has demonstrated 83,000 hours of dispenser cathode life in a device operating at a current density of [2 A/cm.sup.2] and a brightness temperature of 960[degrees]C.
Dispenser cathodes represent a quantitative advancement over the oxide cathodes which preceded them.
Even after 20,000 hours of operation, the advanced dispenser cathodes still perform better than the B-type at the beginning of their life.
Improved helix support materials, progress in helix circuit design, superior magnetic materials and the use of dispenser cathodes have bred a class of rugged, long-lived tubes.
Noteworthy are the use of improved helix support materials, in particular boron nitride and diamond with improved thermal conductivity; progress in helix circuit design, in particular the velocity taper which improved efficiency; superior magnetic material in the form of samarium cobalt; and finally the use of dispenser cathodes.
Dispenser cathodes employing mixtures of exotic oxides are found in all of the tubes.
In a 1988 technical symposium, Louis Dombro, then with Watkins-Johnson, described a series of technological advances which have improved TWT performance.(4) Dombro cited the use of improved helix support materials (boron nitride and diamond) with improved thermal conductivity; progress in helix circuit design, in particular the velocity taper which improved efficiency; superior magnetic material in the form of samarium cobalt; and finally the use of dispenser cathodes.
Dispenser cathodes represent a quantitative advance over the oxide cathodes which preceded them.