Hosing of a long relativistic particle bunch in plasma

TL;DR

This paper experimentally investigates the hosing instability of a long relativistic particle bunch in plasma, showing how it is induced by wakefields from a misaligned short bunch, with results aligning with a theoretical model.

Contribution

It provides the first characterization of hosing in plasma-based accelerators and links experimental observations to a theoretical framework.

Findings

Hosing is induced by wakefields from a short, misaligned bunch.

Hosing develops in the plane of misalignment and is reproducible.

Growth of hosing depends on misalignment and bunch charge.

Abstract

Experimental results show that hosing of a long particle bunch in plasma can be induced by wakefields driven by a short, misaligned preceding bunch. Hosing develops in the plane of misalignment, self-modulation in the perpendicular plane, at frequencies close to the plasma electron frequency, and are reproducible. Development of hosing depends on misalignment direction, its growth on misalignment extent and on proton bunch charge. Results have the main characteristics of a theoretical model, are relevant to other plasma-based accelerators and represent the first characterization of hosing.