Compact, high-repetition rate, ultrashort hard-x-ray source driven by femtosecond laser pulses

Summary form only given. An alternative way to generate ultrashort hard-x-rays is to use low-intensity femtosecond laser pulses in combination with a specially designed "x-ray tube". The femtosecond laser pulses induce photoemission of electrons from a photocathode. The electron bunch is then accelerated towards a high-Z target material by applying an external high-voltage electric field. Hard-x-rays are produced by bremsstrahlung of accelerated electrons and characteristic line emission. In contrast to the existing laser-plasma x-ray sources which require high-power laser systems, for the realization of this novel x-ray source, low-energy, compact, high-repetition rate, commercially available femtosecond lasers can be used. In this presentation we report on our progress in the development and investigation of a femtosecond laser-driven x-ray tube. We demonstrate the influence of relevant parameters (e.g. laser fluence, wavelength, accelerating voltage) on the electron and hard-x-ray generation efficiency using different photocathode and x-ray target materials. The laser-driven hard-x-ray source is characterized in terms of brilliance, spectral properties, and pulse duration. The latter is performed using an ultrafast x-ray streak camera in combination with a laser-triggered accumulation system.