Determination of the reflectivity curve of a spherically bent mica crystal used to diagnose X-ray radiation of relativistic laser plasma

A method for determining the crystal reflectivity curve, based on the use of a broadband X-ray source and an additional spectrometer with preliminarily measured characteristics is proposed. Such a technique does not allow determination of the absolute reflectivity, but makes it possible to measure the dependence of its relative values on the wavelength. Using X-ray radiation of relativistic dense laser plasma, the reflection curve of a spherically bent mica crystal is measured in the range of 6.7–8.7 A. The obtained reflectivity curve is used to correctly interpret X-ray spectra of dense plasma generated during the interaction a petawatt laser pulse with solid targets.