Picosecond Time-resolved Observations of Dense Plasma Shifts

Collin Stillman, University of Rochester

Picosecond time-resolved X-ray spectroscopy is used to measure the spectral line shift of the 1s2p-1s2 transition in He-like Al ions as a function of the instantaneous plasma conditions. The plasma temperature and density are inferred from the Al Heα complex using a nonlocal-thermodynamic-equilibrium atomic physics model. The experimental spectra show a linearly increasing red shift for electron densities of 1 to 5 x 1023 cm-3. The measured line shifts are broadly consistent with a generalized analytic line-shift model based on calculations of a self-consistent field ion sphere model.

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