Abstract

The interest towards developing intense and compact ultrashort x-ray sources is motivated both by scientific applications like time-resolved X-ray diffraction or X-ray absorption spectroscopy[1] and societal applications such as phase contrast imaging for biology and medicine[2]. At LP3 laboratory, such objectives are today achievable thanks to development of hard Kα X-ray pulsed laser plasma source generated by interaction of an ultrahigh intensity femtosecond laser delivering by ASUR laser platform with a solid target. We first determined the absolute yield of the K_α X-ray source (at 17.48 keV) and the X-ray spot size for a wide range of laser intensity (I ~ 10¹⁷ - 2.8×10¹⁹ W/cm²) and for four values of the temporal contrast ratio (6.7×10⁷ < CR < 3.3×10¹⁰). In particular, we measured the highest molybdenum K_α photon production reported to date at 100 Hz[3,4] with a K_α photon flux of 1 × 10¹¹ph/(sr.s) with an X-ray source size less than 90 µm at the driving laser intensity of ~ 10¹⁹ W/cm².

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