Core-Halo Collective Instabilities

TL;DR

This paper investigates how strong space charge effects cause the core and halo of a particle bunch to couple, leading to instabilities at lower thresholds than previously expected, impacting beam stability.

Contribution

It introduces a new understanding of core-halo coupling effects on collective instabilities under strong space charge conditions.

Findings

Core-halo coupling induces instabilities below traditional thresholds.

Transverse modes of the core and halo can effectively interact.

Implications for beam stability in high-intensity accelerators.

Abstract

At strong space charge, transverse modes of the bunch core may effectively couple with those of the halo, leading to instabilities well below the core-only transverse mode-coupling threshold.