High average power ultrafast laser technologies for driving future advanced accelerators

TL;DR

This paper discusses the development of high average power ultrafast laser technologies crucial for advancing laser plasma accelerators towards future high-energy colliders, highlighting current progress and future challenges.

Contribution

It provides an overview of current laser technologies, their limitations, and the research outlook for achieving the high repetition rates and power levels needed for next-generation accelerators.

Findings

Laser plasma accelerators can produce multi-GeV electron beams in 20 cm.

Current laser technology supports energies suitable for colliders but limited by low repetition rates.

Achieving kHz to tens of kHz repetition rates with high energy is a major challenge.

Abstract

Large scale laser facilities are needed to advance the energy frontier in high energy physics and accelerator physics. Laser plasma accelerators are core to advanced accelerator concepts aimed at reaching TeV electron electron colliders. In these facilities, intense laser pulses drive plasmas and are used to accelerate electrons to high energies in remarkably short distances. A laser plasma accelerator could in principle reach high energies with an accelerating length that is 1000 times shorter than in conventional RF based accelerators. Notionally, laser driven particle beam energies could scale beyond state of the art conventional accelerators. LPAs have produced multi GeV electron beams in about 20 cm with relative energy spread of about 2 percent, supported by highly developed laser technology. This validates key elements of the US DOE strategy for such accelerators to enable future colliders but extending best results to date to a TeV collider will require lasers with higher average power. While the per pulse energies envisioned for laser driven colliders are achievable with current lasers, low laser repetition rates limit potential collider luminosity. Applications will require rates of kHz to tens of kHz at Joules of energy and high efficiency, and a collider would require about 100 such stages, a leap from current Hz class LPAs. This represents a challenging 1000 fold increase in laser repetition rates beyond current state of the art. This whitepaper describes current research and outlook for candidate laser systems as well as the accompanying broadband and high damage threshold optics needed for driving future advanced accelerators.