Imaging spectroscopy of microscopic plasmas by means of a mica crystal with a zone-plate surface structure

A method is proposed for obtaining spectra with a high spatial resolution, as high as 0.5 μm. The method involves fabricating a Bragg–Fresnel lens on the surface of a mica crystal. The lens is formed in the direction perpendicular to the dispersion direction. A structure of this sort has been fabricated and has been used to record spectra of the plasmas of Z- and X-pinches. Bragg–Fresnel lenses on crystal surfaces are of much interest for studying the dimensions of the x-ray emission of multiply charged ions formed in plasmas heated by picosecond- and femtosecond-range lasers.