Plasma accelerators (Esary et al 2009 Rev. Mod. Phys. 81 1229) are a potentially important source of high energy, low emittance electron beams with high peak currents generated within a relatively short distance. As such, they may have an important application in the driving of coherent light sources such as the Free Electron Laser (FEL) which operate into the x-ray region (McNeil and Thompson 2010 Nat. Photon. 4 814-21). While novel plasma photocathodes (Hidding et al 2012 Phys. Rev. Lett. 108 035001) may offer orders of magnitude improvement to the normalized emittance and brightness of electron beams compared to Radio Frequency-driven accelerators, a substantial challenge is the energy spread and chirp of beams, which can make FEL operation impossible. In this paper it is shown that such an energy-chirped, ultrahigh brightness electron beam, with dynamically evolving current profile due to ballistic bunching at moderate energies, can generate significant coherent radiation output via the process of Coherent Spontaneous Emission (CSE) (Campbell and McNeil 2012 Proc. FEL2012 (Nara, Japan)). While this CSE is seen to cause some FEL-induced electron bunching at the radiation wavelength, the dynamic evolution of the energy chirped pulse dampens out any high-gain FEL interaction. This work may offer the prospect of a future plasma driven FEL operating in the high-gain Self Amplified CSE mode.
Bibliographical noteKAUST Repository Item: Exported on 2022-06-14
Acknowledgements: The authors wish to thanks to (i) King Abdullah University of Science and Technology (KAUST), http://kaust.edu.sa, and (ii) KAUST Supercomputing Laboratory (KSL) Thuwal, Saudi Arabia, for their help in offering access to SHAHEEN HPC facilities. We gratefully acknowledge the support of STFC's ASTeC department for HPC access, using the STFC Hartree Centre; The Science and Technology Facilities Council Agreement Number 4163192 Release #3; and the John von Neumann Institute for Computing (NIC) on JUROPA at Jülich Supercomputing Centre (JSC), under project HHH20. This work used computational resources of the National Energy Research Scientific Computing Center (NERSC), which is supported by DOE DE-AC02-05CH11231.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.
ASJC Scopus subject areas
- Physics and Astronomy(all)