Demonstration Scheme for a Laser-Plasma-Driven Free-Electron Laser

Abstract

Laser-plasma accelerators are prominent candidates for driving next-generation compact light sources, promising high-brightness, few-femtosecond x-ray pulses intrinsically synchronized to an optical laser, and thus are ideally suited for pump-probe experiments with femtosecond resolution. So far, the large spectral width of laser-plasma-driven beams has been preventing a successful free-electron laser (FEL) demonstration using such sources. In this paper, we study the application of an optimized undulator design and bunch decompression to large-energy-spread beams in order to permit FEL amplification. Numerically, we show a proof-of-principle scenario to demonstrate FEL gain in the vacuum ultraviolet range with electron beams from laser-plasma accelerators as currently available in experiments.

Two-Color Laser-Ionization Injection

“…In the nonlinear laser-driven bubble regime, where the particles are self-trapped, simulations and experiments show that an electron beam with σ x ∼ 0.1 µm, σ px /(m e c) ∼ 1, and n ∼ 0.1 mm mrad can be achieved [3], where σ x is the root-mean-square (rms) beam radius, σ px /(m e c) is the normalized rms transverse momentum, and the normalized transverse emittance can be estimated as n σ x σ px /(m e c). High-quality, laserplasma-accelerated electron beams could be good candidates to drive free-electron lasers, enabling a new generation of low-cost, compact light sources [4,5]. Improved beam phase space characteristics, and, in particular, reduced transverse emittance, is highly desired for light sources and other applications.…”

Diagnostics and controls for spatiotemporal couplings for laser-plasma accelerator drivers

“…Their high accelerating field can provide small footprint, cost-effective electron accelerators for high energy physics [2,3], and their short characteristic wavelength naturally provides fs electron beams, useful for ultrafast science applications [4,5]. Laser plasma accelerators have shown remarkable progress in the past decade, which has coincided with advancement in high power laser technologies.…”

Laser wakefield accelerated electron beam monitoring and control

“…To overcome this difficulty transverse-gradient undulators (TGU) have been investigated as a possibility to achieve a compact XFEL with currently available energy spreads of LWFA electron beams [11,3,12,13,14]. In addition, using conventional accelerator technology phase space rotation of the bunch resulting in decompressed bunches with reduced energy spread [4] and chromatic focusing [5] have also been investigated. In this paper we present our considerations for reducing the energy spread of LWFA electron beams for injection into conventional undulators and electron bunch monitoring.…”

“…This is due to the extremely large electric fields available in plasmas and the resulting drastic reduction of acceleration distance. There has been a lot of interest in using LWFA electron beams for free-electron lasers (FELs) (for example see [2,3,4,5]). Laser acceleration and x-ray FEL (XFEL) demonstration is one of the goals of the Ubiquitous Power Laser for Achieving a Safe, Secure and Longevity Society project within the larger Impulsive Paradigm Change through Disruptive Technologies (ImPACT) program [6].…”