title: Theoretical analysis of hard x-ray generation by nonperturbative interaction of ultrashort light pulses with a metal.
abstract: The interaction of intense femtosecond pulses with metals allows for generating ultrashort hard x-rays. In contrast to plasma theories, tunneling from the target into vacuum is introduced as electron generation step, followed by vacuum acceleration in the laser field and re-entrance into the target to generate characteristic x-rays and Bremsstrahlung. For negligible space charge in vacuum, the Kα flux is proportional to the incident intensity and the wavelength squared, suggesting a strong enhancement of the x-ray flux by mid-infrared driving pulses. This prediction is in quantitative agreement with experiments on femtosecond Cu Kα generation.
authors.affiliation: Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie , 12489 Berlin, Germany.
authors.forename: Jannick
authors.initials: J
authors.lastname: Weisshaupt
authors.affiliation: Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie , 12489 Berlin, Germany.
authors.forename: Vincent
authors.initials: V
authors.lastname: Juvé
authors.affiliation: Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie , 12489 Berlin, Germany.
authors.forename: Marcel
authors.initials: M
authors.lastname: Holtz
authors.affiliation: Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie , 12489 Berlin, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Woerner
authors.affiliation: Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie , 12489 Berlin, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Elsaesser