X-ray Diagnostic Development for Electron Beam Driven WDM Experiments

A platform for characterizing the equation-of-state of the warm dense matter (WDM) regime is being developed on an intense, relativistic electron accelerator1,2. DARHT Axis-I generates a 100-ns-long electron pulse with a beam current of 1.7 kA and energy of 19.8 MeV that deposits energy into a thin metal foil heating it to a warm dense plasma. The collisional ionization of the target by the electron beam produces an anisotropic angular distribution of K- and L-shell radiation, in addition to a continuum of both scattered electrons and Bremsstrahlung up to the beam energy of 19.8 MeV. A bolometer3 and an array of diamond photo-conducting detectors will be calibrated on a 1-MA linear transformer driver at the University of Michigan4. These diagnostics will then be fielded on the Axis-I electron linac to characterize the background Bremsstrahlung and scattered electrons. Additionally, a gated X-ray imager is under development to acquire temporal and spatial measurements of X-rays. The goal of these diagnostics is to provide temperature and density measurements of the warm dense plasma for the first time with this heating technique.