X-ray diagnostic developments for laser-matter interaction experiments

The paper reports on progress in the development of new X-ray diagnostic instruments required for laser-matter interaction experiments, with emphasis on the range of soft and hard X-ray emission between 100 eV and 100 keV. For high spatial/temporal X-ray measurements, a soft X-ray streak camera with lamellar electron optics has been developed. This camera is used with a cylindrical mirror for diagnosis in the range 100 eV to a few keV. Recently, a new optimized prototype has been tested and higher spatial/temporal resolution has been measured. For soft X-ray imaging techniques (from 50 eV to a few keV) a Wolter microscope has been developed and tested, and a detection system has been built around a small image converter tube with an X-ray photocathode and a phosphor screen. The image on this screen is read by a charge-coupled device (CCD) working in the visible spectral range. For higher energy X-ray imaging, a simple pinhole camera is used which is connected to an electronic image readout, using a CCD array that provides two-dimensional spatial information in the 2-10 keV spectral range. For spectroscopic measurements, an X-ray spectrometer is used, with a curved TlA phosphate crystal and a linear array of 4096 photodiodes with automatic 12 bit digitization (range 1.3-28 keV). For accurate energy balance measurements in the keV spectral range, a number of quasi-linear adiabatic X-ray calorimeters and bolometers have been built for which absolute electrical calibration is possible. The paper also presents some preliminary results on X-ray calibration with a pulsed soft X-ray source working with various gases. (author). 6 refs, 11 figs