The Weakened Weibel Electromagnetic Instability of Ultra-Intense Mev Electron Beams in Multi-Layer Solid Structure

Abstract

Abstract-The Weibel instability of intense and collimated MeV fast electron beams in multi-layer structure is investigated. It is found that the electromagnetic instability of fast electron beams can be significantly suppressed by this structure. A strong magnetic field will be created at the interfaces between materials with different resistivities as these fast electrons are injected into this structure. It obstructs the transverse movement of the fast electrons and confines them to propagate along the interfaces. In consequence, the positive feedback loop between magnetic field perturbation and electrons density perturbation is broken, and the Weibel instability is thus weakened. Furthermore, the calculated results for Au/Si multi-layer structure by a hybrid Particle in Cell code have proven this weakening effect on the Weibel instability of intense fast electron beams. Because of the high energy-density delivered by the MeV electrons, these results indicate applications in high-energy physics, such as radiography, fast electron beam focusing, and perhaps fast ignition.

A study of the effect of self‐generated pressure gradient sources on the resistive filamentation instability

“…In this order, recent studies have shown that the resistive electromagnetic instabilities of fast electron beams can be significantly weakened by the multi‐layer structure where generating this magnetic field, which is related to the rotation of the gradient of the resistivity, pushes electrons towards the regions of higher resistivity. [ 11 ] However, it is found that other mechanisms tend to contribute to the self‐generated magnetic fields and transport process. [ 6,7,12 ] In this regard, in our previous work, we modelled the effects of plasma heating, pinching , and Nernst (arising from the hot electrons flux) on the resistive filamentation modes in a magnetized anisotropic plasma.…”