Soft-x-ray harmonic comb from relativistic electron spikes.

  title={Soft-x-ray harmonic comb from relativistic electron spikes.},
  author={A. S. Pirozhkov and Masaki Kando and T. Zh. Esirkepov and Pablo Gallegos and Hamad Ahmed and Eugene N. Ragozin and Anatoly Ya Faenov and T A Pikuz and Tetsuya Kawachi and Akito Sagisaka and James K. Koga and Mireille Coury and J Green and P Foster and Carsten Brenner and Brendan Dromey and Daniel R. Symes and Michiaki Mori and Keigo Kawase and Takashi Kameshima and Yasushi Fukuda and Longquan Chen and Izuru Daito and Koichi Ogura and Yoshiaki Hayashi and Hideyuki Kotaki and Hiromitsu Kiriyama and Hajime Okada and Nobuyuki Nishimori and Takashi Imazono and Ken-ichi Kondo and Tsuyoshi Kimura and Tsuyoshi Tajima and Hiroyuki Daido and Pradhi Rajeev and Paul McKenna and Marco Borghesi and Daniel Neely and Yukako Kato and S. V. Bulanov},
  journal={Physical review letters},
  volume={108 13},
We demonstrate a new high-order harmonic generation mechanism reaching the "water window" spectral region in experiments with multiterawatt femtosecond lasers irradiating gas jets. A few hundred harmonic orders are resolved, giving μJ/sr pulses. Harmonics are collectively emitted by an oscillating electron spike formed at the joint of the boundaries of a… CONTINUE READING