A Streaked X-ray Spectroscopy Platform for Rapidly Heated, Near-solid Density Plasmas

Collin Stillman, University of Rochester

A picosecond time-resolved X-ray spectroscopy platform has been developed to study the thermal line emission from rapidly heated solid targets containing buried aluminum or iron layers. The targets are driven by high-contrast 1ω or 2ω laser pulses at focused intensities up to 1 x 1019 W/cm2. The X-ray spectrometers use an elliptical focusing geometry to improve spectral coverage and throughput at the detector. Picosecond time resolution is achieved using an ultrafast X-ray streak camera. Time-integrated spectra are collected on each shot to correct the streaked data for variations in X-ray spectral sensitivity. The time-integrated spectrometer uses three crystals to disperse X-rays with energies between 800 and 2,100 eV with moderate (E/ΔE ~ 450) resolving power. The streaked spectrometers use four crystals at a higher resolving power (E/ΔE ~ 650) to measure the brightest thermal lines in the 1,300-1,700 eV spectral range. The measured spectra are compared to synthetic spectra from a collisional-radiative atomic physics model to infer the average plasma conditions in the buried layer.

Abstract Author(s): C.R. Stillman, P.M. Nilson, S. Ivancic, C. Mileham, I.A. Begishev, R.K. Junquist, D.H. Froula