Recovery time of a plasma-wakefield accelerator

Abstract

The interaction of intense particle bunches with plasma can give rise to plasma wakes1,2 capable of sustaining gigavolt-per-metre electric fields3,4, which are orders of magnitude higher than provided by state-of-the-art radio-frequency technology5. Plasma wakefields can, therefore, strongly accelerate charged particles and offer the opportunity to reach higher particle energies with smaller and hence more widely available accelerator facilities. However, the luminosity and brilliance demands of high-energy physics and photon science require particle bunches to be accelerated at repetition rates of thousands or even millions per second, which are orders of magnitude higher than demonstrated with plasma-wakefield technology6,7. Here we investigate the upper limit on repetition rates of beam-driven plasma accelerators by measuring the time it takes for the plasma to recover to its initial state after perturbation by a wakefield. The many-nanosecond-level recovery time measured establishes the in-principle attainability of megahertz rates of acceleration in plasmas. The experimental signatures of the perturbation are well described by simulations of a temporally evolving parabolic ion channel, transferring energy from the collapsing wake to the surrounding media. This result establishes that plasma-wakefield modules could be developed as feasible high-repetition-rate energy boosters at current and future particle-physics and photon-science facilities.

C$^3$ Demonstration Research and Development Plan

“…The possible application of such a technology to C 3 would require experimental investigation with the bunch structure and beam format of C 3 . Experiments targeted at understanding this technology and associated issues such as plasma recovery time [61] could utilize the C 3 demonstrator facility.…”

Detector Simulation Challenges for Future Accelerator Experiments

“…The beam-induced background (BIB) created by beam muons decaying in flight places new and unique demands on simulation [16]. Wakefield acceleration also offers a possibility for reaching high energies more compactly in the further future [17].…”

Preservation of beam quality in a plasma-wakefield accelerator

“…The resulting separation of electrons and ions creates strong electromagnetic fields, or plasma wakefields, which can be used both to accelerate and focus a trailing particle bunch. In beam-driven plasma-wakefield accelerators (PWFAs), experiments have already demonstrated large energy gain 9,10 , high energy-transfer efficiency from the driver to the trailing bunch 11 , acceleration across multi-metre-scale accelerator stages 12 , as well as potential for high repetition rate 13 .…”