Application of X-ray Lasers as Imaging and Plasma Diagnostics

Abstract

Since the first demonstration of a soft x-ray laser (XRL) at the Lawrence Livermore National Laboratory1, XRLs have been considered for applications in the fields of microscopy, holography, material science, and plasma physics. With its short wavelength, controllable short pulse duration, high brightness and coherence, the XRL is ideally suited as a plasma diagnostic to image rapidly evolving (< 1 ns) laser-driven plasmas with high electron density (1021 cm-3 < ne< 1024 cm-3). Over the past 2 years, we have made significant progress in the development of short-wavelength multilayer mirrors and beam splitters in the soft x-ray regime and are pioneering the development of XRLs as an imaging diagnostic for laser plasmas. We have used XRLs as high fluency monochromatic radiographic sources2. We have also used XRLs to measure 1-D density gradients of laser plasmas using the Moiré deflectometry technique2. We have began testing a 2-D XRL interferometer, in the Mach-Zehnder configuration, which will allow us to measure absolute 2-D plasma density profiles. The demonstration of the 2-D interferometer and the application of this interferometer to understand the physics of laser plasmas will be our primary focus for the near future. We are also working on the development of enhanced-coherence, high-brightness XRLs. During the past year we have experimentally and theoretically characterized shaped XRLs3 as part of our research on adaptive spatially filtered XRLs to develop a single-mode oscillator which has application beyond the 2-D interferometer and can yield a 3-D hologram of an imploding inertial confinement fusion (ICF) capsule.