Soft X-ray harmonic comb from relativistic electron spikes
Plasma Physics
2012-04-03 v1 Optics
Abstract
We demonstrate a new high-order harmonic generation mechanism reaching the `water window' spectral region in experiments with multi-terawatt femtosecond lasers irradiating gas jets. A few hundred harmonic orders are resolved, giving uJ/sr pulses. Harmonics are collectively emitted by an oscillating electron spike formed at the joint of the boundaries of a cavity and bow wave created by a relativistically self-focusing laser in underdense plasma. The spike sharpness and stability are explained by catastrophe theory. The mechanism is corroborated by particle-in-cell simulations.
Cite
@article{arxiv.1201.0333,
title = {Soft X-ray harmonic comb from relativistic electron spikes},
author = {A. S. Pirozhkov and M. Kando and T. Zh. Esirkepov and P. Gallegos and H. Ahmed and E. N. Ragozin and A. Ya. Faenov and T. A. Pikuz and T. Kawachi and A. Sagisaka and J. K. Koga and M. Coury and J. Green and P. Foster and C. Brenner and B. Dromey and D. R. Symes and M. Mori and K. Kawase and T. Kameshima and Y. Fukuda and L. Chen and I. Daito and K. Ogura and Y. Hayashi and H. Kotaki and H. Kiriyama and H. Okada and N. Nishimori and T. Imazono and K. Kondo and T. Kimura and T. Tajima and H. Daido and P. Rajeev and P. McKenna and M. Borghesi and D. Neely and Y. Kato and S. V. Bulanov},
journal= {arXiv preprint arXiv:1201.0333},
year = {2012}
}