Plasma lens for high-flux x-ray radiation

In this work we describe new kind of refractive lens for focusing of high flux X-ray radiation of next generation X-ray sources. It is proposed to create such lens driving relatively low electric currents inside evacuated capillary made of low-Z material. The numerical simulations show that during the 0.1 - 3 microsecond(s) , 2-6 kA current pulse, the wall sustained stable capillary discharge plasma forms a concave density profile with almost parabolic index of refraction. Compared to solid materials, the plasma is able to sustain 2-3 order of magnitude larger doze ~100 eV/atom and can operate at larger fluxes and specifically in the relatively long wavelength region 1-4 keV where solid materials have dramatically larger absorption. For radiation sources similar to LCLS, the plasma lens can be placed right at the exit of undulator and deliver 3-4 orders of magnitude larger fluxes in the focal spot.