Observations of continuum depression in warm dense matter with x-ray Thomson scattering.

Research paper by L B LB Fletcher, A L AL Kritcher, A A Pak, T T Ma, T T Döppner, C C Fortmann, L L Divol, O S OS Jones, O L OL Landen, H A HA Scott, J J Vorberger, D A DA Chapman, D O DO Gericke, B A BA Mattern, G T GT Seidler, et al.

Indexed on: 29 Apr '14Published on: 29 Apr '14Published in: Physical review letters


Detailed measurements of the electron densities, temperatures, and ionization states of compressed CH shells approaching pressures of 50 Mbar are achieved with spectrally resolved x-ray scattering. Laser-produced 9 keV x-rays probe the plasma during the transient state of three-shock coalescence. High signal-to-noise x-ray scattering spectra show direct evidence of continuum depression in highly degenerate warm dense matter states with electron densities ne>1024  cm-3. The measured densities and temperatures agree well with radiation-hydrodynamic modeling when accounting for continuum lowering in calculations that employ detailed configuration accounting.