Cumulation of High-current Electron Beams: Theory and Experiment

TL;DR

This paper presents a new theoretical and experimental study of high-current electron beam cumulation in relativistic vacuum diodes, highlighting a low-energy spread mechanism distinct from magnetic focusing.

Contribution

It introduces a novel cumulation mechanism based on electrostatic repulsion with experimental validation, differing from traditional magnetic focusing methods.

Findings

Confirmed theoretical predictions with experimental data

Identified a low-energy spread in electron beams during cumulation

Demonstrated a new mechanism for high-current electron beam focusing

Abstract

A drastic cumulation of current density caused by electrostatic repulsion in relativistic vacuum diodes with ring-type cathodes is described theoretically and confirmed experimentally. The distinctive feature of the suggested cumulation mechanism over the conventional one, which relies on focusing a high-current beam by its own magnetic field, is a very low energy spread of electrons in the region of maximal current density that stems from a laminar flow profile of the charged-particle beam.