Sub-femtosecond hard X-ray radiation generated by electron bunches ejected from water jet

Abstract

AbstractA new two-step approach for frequency conversion of laser radiation towards hard X-rays is developed and examined experimentally. Fast electrons are produced in a form of thin jets at the first stage, as an intense femtosecond laser pulses impinges on a micrometer water target. In the second stage the accelerated electrons hit a secondary metal target and generate characteristic K-shell radiation with a duration down to sub-femtosecond. It is shown that counter propagating laser radiation experiences very strong up-shift with up to 6 × 103 times of fundamental frequency by reflection from the electron jets.