Linear colliders based on laser-plasma accelerators

Abstract

Laser-plasma accelerators are capable of sustaining accelerating fields of 10–100 GeV/m, 100–1000 times that of conventional technology and the highest fields produced by any of the widely researched advanced accelerator concepts. Laser-plasma accelerators also intrinsically accelerate short particle bunches, several orders of magnitude shorter than that of conventional technology, which leads to reductions in beamstrahlung and, hence, savings in the overall power consumption to reach a desired luminosity. These properties make laser-plasma accelerators a promising accelerator technology for a more compact, less expensive high-energy linear collider providing multi-TeV polarized leptons. In this submission to the Snowmass 2021 Accelerator Frontier, we discuss the motivation for a laser-plasma-accelerator-based linear collider, the status of the field, and potential linear collider concepts up to 15 TeV. We outline the research and development path toward a collider based on laser-plasma accelerator technology, and highlight near-term and mid-term applications of this technology on the collider development path. The required experimental facilities to carry out this research are described. We conclude with community recommendations developed during Snowmass.

The science case for an intermediate energy advanced and novel accelerator linear collider facility

“…These recommendations are parts of the timeline (see figure 4 and [6] for a TeV collider timeline), which envisions the development of the science case and collider demo design by 2030, which will feed into the technical design report.…”

“…With sufficient science motivation, one possible IEF that could be considered is a 20-100 GeV center-of-mass energy ANA-based linear lepton collider. In what follows we focus on the science case for an IEF since the necessary R&D effort as well as potential near term applications of ANAs are outlined in other white papers submitted to Snowmass21 [6][7][8]. The goal of the proposed IEF is to both carry out particle physics measurements in the 20-100 GeV ranges, as well as to serve as a ANA demonstrator facility.…”

“…Electron beams have been accelerated up to 8 GeV over 20 cm at the Lawrence Berkeley National Laboratory using a PW laser pulse propagating in a plasma channel [5]. A discussion of the status of ANA research as well as the necessary avenues for achieving progress in this field may be found in the whitepapers "Linear collider based on laser-plasma accelerators", "AWAKE, Plasma Wakefield Acceleration of Electron Bunches for Near and Long Term Particle Physics Applications", and "Near Term Applications driven by Advanced Accelerator Concepts" submitted to Snowmass21 [6][7][8].…”

Plasma-based particle sources

“…In particular, laser-wakefield accelerators (LWFAs), which are based on laser-plasma interactions, can produce high-brightness femtosecond electron bunches with low transverse emittance from a compact setup (for current state-of-the art parameters see table 1). However, some parameters of LWFA electron beams, such as transverse emittance, energy spread, laser-to-beam conversion efficiency or pulse repetition rate can be even further improved and more specifically tailored to their application, such as for future particle colliders [1] or laser-driven free-electron lasers (FELs) [2]. The specific properties of future particle colliders are determined by the requirements of future high-energy physics experiments, which are currently being evaluated.…”

“…The beam energies can only be achieved by combining numerous acceleration stages. Considerations of power requirements and feasibility of plasma-based concepts indicate a demand for beams with high charge per bunch, low normalized emittances of < 0.1 μm and a relative energy spreads of < 1% [1]. FELs driven by plasma-based accelerators can be considered an intermediate step toward this goal as, depending on the wavelength of the FEL emission, the electron beam requirements are somewhat relaxed and the required beam energy can be achieved in a single accelerator stage.…”