Guided mode evolution and ionization injection in meter-scale multi-GeV laser wakefield accelerators
Plasma Physics
2023-09-19 v1 Accelerator Physics
Optics
Abstract
We show that laser wakefield electron accelerators in meter-scale, low density hydrodynamic plasma waveguides operate in a new nonlinear propagation regime where sustained beating of lowest order modes of the ponderomotively modified channel plays a significant role, whether or not the injected pulse is linearly matched to the guide. For a continuously doped gas jet, this mode beating effect leads to ionization injection and a striated multi-GeV energy spectrum of multiple quasi-monoenergetic peaks; the same process in a locally doped jet produces single multi-GeV peaks with <10% energy spread. A 3-stage model of drive laser pulse evolution and ionization injection characterizes the beating effect and explains our experimental results.
Cite
@article{arxiv.2309.09930,
title = {Guided mode evolution and ionization injection in meter-scale multi-GeV laser wakefield accelerators},
author = {J. E. Shrock and E. Rockafellow and B. Miao and M. Le and R. C. Hollinger and S. Wang and A. J. Gonsalves and A. Picksley and J. J. Rocca and H. M. Milchberg},
journal= {arXiv preprint arXiv:2309.09930},
year = {2023}
}