We studied mathematical models for degradation behaviors of current and voltage in electron guns especially using oxide cathodes. We found that the current and the voltage, and , follow the stretched exponential decay in oxide cathodes. On this basis, we derived a general expression for the time-dependent current–voltage relation as , where is a time-dependent exponent and the perveance, , is a function of . The exponent indicates the deviation of the classical Child–Langmuir relation . This deviation is attributed to the gradual change of the electron gun geometry over time.
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Rapid Communication| January 07 2005
Time-dependent current-voltage relation in electron guns
Byung Mook Weon;
Byung Mook Weon, Jung Ho Je; Time-dependent current-voltage relation in electron guns. J. Appl. Phys. 1 February 2005; 97 (3): 036101. https://doi.org/10.1063/1.1846938
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