Scheme for proton-driven plasma-wakefield acceleration of positively charged particles in a hollow plasma channel

TL;DR

This paper proposes a novel plasma wakefield acceleration scheme using a hollow plasma channel with proton drivers, enabling stable, long-distance acceleration of positively charged particles at high gradients.

Contribution

It introduces a new hollow plasma channel method for positively charged particle acceleration, improving stability and efficiency over traditional uniform plasma approaches.

Findings

Stable acceleration of positively charged particles over 1 km

Average acceleration gradient of 1.3 GeV/m

Charge separation at the channel wall enhances focusing

Abstract

A new scheme for accelerating positively charged particles in a plasma wakefield accelerator is proposed. If the proton drive beam propagates in a hollow plasma channel, and the beam radius is of order of the channel width, the space charge force of the driver causes charge separation at the channel wall, which helps to focus the positively charged witness bunch propagating along the beam axis. In the channel, the acceleration buckets for positively charged particles are much larger than in the blowout regime of the uniform plasma, and stable acceleration over long distances is possible. In addition, phasing of the witness with respect to the wave can be tuned by changing the radius of the channel to ensure the acceleration is optimal. Two dimensional simulations suggest that, for proton drivers likely available in future, positively charged particles can be stably accelerated over 1 km with the average acceleration gradient of 1.3 GeV/m.