Boosted high-harmonics pulse from a double-sided relativistic mirror

Esirkepov, T. Z.; Bulanov, S. V.; Kando, Masaki; Pirozhkov, A. S.; Zhidkov, A.*

An ultra-bright high-power X- and -radiation source is proposed. A high-density thin plasma slab, accelerating in the radiation pressure dominant regime by an ultra-intense electromagnetic wave, reflects a counter-propagating relativistically strong electromagnetic wave, producing extremely time-compressed and intensified radiation. The reflected light contains relativistic harmonics generated at the plasma slab, all upshifted with the same factor as the fundamental mode of the incident light. The theory of an arbitrarily moving thin plasma slab reflectivity is presented.