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ASTM F83-71(2002)
Standard Practice for Definition and Determination of Thermionic Constants of Electron Emitters
5 стр.
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Разработчик:
Зарубежные/ASTM
ICS:
01.040.31 Electronics (Vocabularies) / Электроника (Словари)31.100 Electronic tubes / Электронные лампы
Сборник (ASTM):
10.04 Electronics; Declarable Substances in Materials; 3D Imaging Systems; Additive Manufacturing Technologies / Электроника; Декларируемые вещества в материалах; Системы 3D-визуализации; Аддитивные технологии производства
Тематика:
Electronics
Описание
Реферат

This practice covers the definition and interpretation of the commonly used thermionic constants of electron emitters with appended standard methods of measurement. Cathode materials shall alternatively be evaluated by relating the temperature-limited emission to fundamental properties of the emitter, particularly the work function. Comparisons are made between emitters using the thermionic constants such as the work function, emission constant, and the temperature dependence of the work function. These thermionic constants are geometry and field effects-independent, but exhibit variations under different conditions. The pertinent equations the Richardson-Dushman equation of electron emission to evaluate the effective work function, which in turn, shall be used to find the Richardson work function and the true work function. Sample computations are also detailed.

Область применения

1.1 This practice covers the definition and interpretation of the commonly used thermionic constants of electron emitters (1, 2, 3), with appended standard methods of measurement.

Ключевые слова:
electron emitters; electron tube materials; termionic constants; work function