DMX: An absolutely calibrated time-resolved broadband soft x-ray spectrometer designed for MJ class laser-produced plasmas (invited)

In high flux (1013–15 W/cm2) laser-plasma interaction, a large part of the incoming laser energy is radiated into soft x-rays. To determine both the shape of this spectrum and the conversion efficiency, we have designed and tested an absolutely calibrated broadband soft x-ray spectrometer with a high temporal resolution (100 ps). The detector in this spectrometer is a new coaxial x-ray diode coupled with a fast single shot oscilloscope (French IN7100 with 7 GHz frequency response cutoff). Both absolute calibrations (x-ray response of diodes) and relative calibrations (filters and mirrors) have used the French synchrotron beam lines at Laboratoire pour l’utilisation du Rayonnement Electromagnetique (LURE) in Orsay. The initial version of this instrument was first successfully implemented on laser plasmas experiments at the Phebus facility in France and an improved version is now operating at the Omega laser facility in Rochester, New York. The emitted x-ray spectrum is absolutely measured in 18 broad bands...

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