Physical nature of “anomalous” electrons in high current vacuum diodes

DOI: https://doi.org/10.5937/vojtehg69-30116
Keywords: numerical simulation, vacuum electronics, vacuum breakdown

Abstract


Introduction/purpose: A fundamental theoretical explanation is given for the fact that in subnanosecond vacuum diodes there exists a group of electrons with kinetic energies much higher than the applied voltage (multiplied by the value of the elementary charge) qUmax.

Methods: A mathematical method is used based on the numerical solution of the Vlasov-Poisson differential equations system for one-dimensional vacuum diodes of various designs.

Results: It is shown in detail that the so-called "anomalous" electrons appear in the transient time domain characterizing the processes of establishing current flow in vacuum diodes.

Conclusion: It has been convincingly shown that the presence of “anomalous” electrons is not associated with either the diode design or the presence of additional current carriers. In vacuum diodes with a subnanosecond leading edge of the voltage pulse, the excess of energy over qUmax can be over 20%.

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Published
2021/03/22
Issue
Vol. 69 No. 2 (2021): April – June
Section
Original Scientific Papers
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