title: Enhancement of x-ray line emission from plasmas produced by short high-intensity laser double pulses.
abstract: Femtosecond laser-produced plasmas are bright ultrafast line x-ray sources potentially suitable for different applications including material science and biology. The conversion efficiency of the laser energy incident onto a solid target into the x-ray emission is significantly enhanced when a laser prepulse precedes the main pulse. The details of x-ray line emission from solid targets irradiated by a pair of ultrashort laser pulses are investigated both theoretically and experimentally. Insight into spatial and temporal characteristics of the line x-ray source is provided by numerical simulations and a simplified analytical model. Optimal time separation of the laser pulses is searched for in order to reach the maximum conversion of laser energy into the emission of selected x-ray lines. We deduced how the optimal pulse separation scales with laser and target parameters.
authors.affiliation: Institute for Laser Physics, S.C. Vavilov State Optical Institute, Birzhevaya line 12, 193232 St. Petersburg, Russia.
authors.forename: A A
authors.initials: AA
authors.lastname: Andreev
authors.forename: J
authors.initials: J
authors.lastname: Limpouch
authors.forename: A B
authors.initials: AB
authors.lastname: Iskakov
authors.forename: H
authors.initials: H
authors.lastname: Nakano