Charge transport and mode transition in dual-energy electron beam diodes

TL;DR

This paper identifies five charge transport modes in dual-energy electron beam diodes, revealing how electron energy and current density influence mode transitions through simulations and theoretical analysis.

Contribution

It introduces a generalized analysis for multi-component electron beams and proposes a theoretical piecewise function for transmitted current density.

Findings

Five distinct charge transport modes identified.

Theoretical model agrees with PIC simulation results.

Insights enable new high-performance vacuum electronic device designs.

Abstract

This Letter uncovers five distinct charge transport modes and their transitions in dual-energy electron beam diodes. We via first-principle particle-in-cell (PIC) simulations establish that the specific mode (e.g., space charge oscillations) and the current transport characteristics are essentially governed by the interplay between the electron beam energy and injected current density. A generalized analysis is conducted for n-component electron beams, and a theoretical piecewise function is for the transmitted current density proposed, which agrees well with the PIC results under designed conditions. The discovery provides a mechanistic picture of multiple electron beam transport in diodes, paving the way for novel designs of high-performance modern vacuum electronic devices.