Control of laser plasma accelerated electrons for light sources

Thomas André ,S Corde,C Évain,F Polack,D Dennetière,F Marteau,S Bielawski,P Rousseau,C Szwaj,J Gautier,M Khojoyan,J Vétéran,C Thaury,F Briquez,B Mahieu,M Labat,Carlos De Oliveira ,Christian Herbeaux ,Charles Bourassin-Bouchet ,Charles Kitégi ,Tarik El Ajjouri ,Patrick Rommeluère ,P Berteaud,Keihan Tavakoli ,Eléonore Roussel ,N Leclercq,Olivier Marcouillé ,K Ta Phuoc,Amin Ghaith ,C Benabderrahmane,Mathieu Valléau ,Jean-Pierre Duval ,Amar Tafzi ,Slava Smartsev ,Nicolas Hubert ,Victor Malka ,Yannick Dietrich ,Mourad Sebdaoui ,Frédéric Blache ,Alexandre Loulergue ,Patrick N'gotta ,Guillaume Lambert ,Igor Andriyash ,Alain Lestrade ,Moussa El Ajjouri ,François Bart ,J P Goddet,L Chapuis,M.e Couprie

doi:10.1038/s41467-018-03776-x

Abstract

With gigaelectron-volts per centimetre energy gains and femtosecond electron beams, laser wakefield acceleration (LWFA) is a promising candidate for applications, such as ultrafast electron diffraction, multistaged colliders and radiation sources (betatron, compton, undulator, free electron laser). However, for some of these applications, the beam performance, for example, energy spread, divergence and shot-to-shot fluctuations, need a drastic improvement. Here, we show that, using a dedicated transport line, we can mitigate these initial weaknesses. We demonstrate that we can manipulate the beam longitudinal and transverse phase-space of the presently available LWFA beams. Indeed, we separately correct orbit mis-steerings and minimise dispersion thanks to specially designed variable strength quadrupoles, and select the useful energy range passing through a slit in a magnetic chicane. Therefore, this matched electron beam leads to the successful observation of undulator synchrotron radiation after an 8 m transport path. These results pave the way to applications demanding in terms of beam quality.

Highlights

The capacity of plasma waves to produce and sustain extremely strong electric fields gave rise to a high interest for plasma-based electron acceleration[1]
Worldwide efforts presently aim at improving laser wakefield acceleration (LWFA) performance, targeting applications, such as undulator synchrotron radiation[5,6], free electron lasers[7,8,9], intrinsic betatron radiation[10], ultrafast electron diffraction sources[11] and even highenergy colliders[12]
While conventional accelerators deliver microradian divergence and per mille of energy spread beams, the quality issues of LWFA require specific electron beam manipulation in order to fit the FEL application requirements, in particular to handle the large initial divergence with conventional permanent magnet quadrupole type[5,6,33,34,35] or plasma-based[36,37,38,39] focusing devices, and to mitigate the energy spread with magnetic chicanes for beam decompression[40,41,42] or transverse gradient undulators[43]

Summary

Introduction

The capacity of plasma waves to produce and sustain extremely strong electric fields gave rise to a high interest for plasma-based electron acceleration[1]. While conventional accelerators deliver microradian divergence and per mille of energy spread beams, the quality issues of LWFA require specific electron beam manipulation in order to fit the FEL application requirements, in particular to handle the large initial divergence with conventional permanent magnet quadrupole type[5,6,33,34,35] or plasma-based[36,37,38,39] focusing devices, and to mitigate the energy spread with magnetic chicanes for beam decompression[40,41,42] or transverse gradient undulators[43]. A slit equipped magnetic chicane decompresses the beam and selects the desired energy range We matched this shaped electron beam to successfully produce undulator radiation

Methods

Results

Conclusion