High-quality electron beam generation in a proton-driven hollow plasma wakefield accelerator

Y Li,O Mete-Apsimon,K V Lotov,G Xia,A P Sosedkin,K Hanahoe

doi:10.1103/physrevaccelbeams.20.101301

Abstract

Simulations of proton-driven plasma wakefield accelerators have demonstrated substantially higher accelerating gradients compared to conventional accelerators and the viability of accelerating electrons to the energy frontier in a single plasma stage. However, due to the strong intrinsic transverse fields varying both radially and in time, the witness beam quality is still far from suitable for practical application in future colliders. Here we demonstrate efficient acceleration of electrons in proton-driven wakefields in a hollow plasma channel. In this regime, the witness bunch is positioned in the region with a strong accelerating field, free from plasma electrons and ions. We show that the electron beam carrying the charge of about 10% of 1 TeV proton driver charge can be accelerated to 0.6 TeV with preserved normalized emittance in a single channel of 700 m. This high quality and high charge beam may pave the way for the development of future plasma-based energy frontier colliders.

Highlights

Particle-beam-driven plasma wakefield accelerators (PWFAs) have achieved enormous progress in recent decades [1,2] and have experimentally demonstrated electron-driven acceleration up to 85 GeV [3]
The witness bunch is positioned in the region with a strong accelerating field, free from plasma electrons and ions
We show that the electron beam carrying the charge of about 10% of 1 TeV proton driver charge can be accelerated to 0.6 TeV with a preserved normalized emittance in a single channel of 700 m

Summary

INTRODUCTION

Particle-beam-driven plasma wakefield accelerators (PWFAs) have achieved enormous progress in recent decades [1,2] and have experimentally demonstrated electron-driven acceleration up to 85 GeV [3]. An encouraging experiment at FACET of SLAC National Accelerator Laboratory has demonstrated an 8-cm-long hollow plasma channel with a radius of 250 μm, in which the measured decelerating gradient on the driving positron beam has reached 230 MeV=m [24]. [36], the wakefield is driven by a short proton bunch in a hollow channel, and the witness beam can simultaneously have a high charge and experience a strong accelerating field. The latter features enable high energy transfer efficiencies, approaching those in the strong blowout regime in uniform plasmas driven by electrons [37].

SCHEMATIC OF THE PROPOSED SCHEME AND PARAMETERS FOR PIC SIMULATIONS

BEAM DYNAMICS IN THE HOLLOW PLASMA CHANNEL

Findings

DISCUSSION

CONCLUSIONS