Single-Shot X-Ray Absorption Fine Structure Measurements of Ambient Aluminium Using a Portable X-Pinch Backlighter in Dispersive Geometry Show Affiliations

The energy-dispersive x-ray absorption fine structure spectroscopy (EDXAFS) allows simultaneous measurement of density, temperature, as well as the electronic and geometric structure of dense samples. These measurements are especially applicable to strongly coupled and optically opaque states of matter produced in laser-driven dynamic compression and current heating experiments which are inaccessible to optical methods such as Thompson scattering. Dry Pinch I, a portable X-pinch developed at Imperial College, can produce on-sample photon flux of >10000 photons / eV around the Aluminium K edge within a single ~1 ns long x-ray burst. In the spectral region of interest, the X-pinch has a smooth and continuous spectrum enabling EDXAFS measurements. Using a 15x50mm spherical crystal (r=180mm), the geometry provides a spectral bandwidth of 100 eV around the Aluminium K edge at 1559 eV (sufficient for near-edge structure measurements). As a proof-of-concept, we used the X-pinch to successfully measure the near-edge spectrum of a 2 micrometer thick aluminium foil in a single-shot mode. Currently, we are designing an experiment coupling the X-pinch backlighter to a separate x-ray or laser driver that can isochorically heat thin foil targets.