Temperature and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mi>K</mml:mi><mml:mi>α</mml:mi></mml:mrow></mml:math>-yield radial distributions in laser-produced solid-density plasmas imaged with ultrahigh-resolution x-ray spectroscopy

Abstract

We study warm dense matter formed by subpicosecond laser irradiation at several ${10}^{19}\text{ }\text{W}/{\text{cm}}^{2}$ of thin Ti foils using x-ray spectroscopy with high spectral $(E/\ensuremath{\Delta}E\ensuremath{\sim}15,000)$ and one-dimensional spatial $(\ensuremath{\Delta}x=13.5\text{ }\ensuremath{\mu}\text{m})$ resolutions. $\text{Ti}\text{ }K\ensuremath{\alpha}$ doublets modeled by line-shape calculations are compared with Abel-inverted single-pulse experimental spectra and provide radial distributions of the bulk-electron temperature and the absolute-photon number $K\ensuremath{\alpha}$ yield in the target interiors. A core with $\ensuremath{\sim}40\text{ }\text{eV}$ extends homogeneously up to ten times the laser-focus size. The spatial distributions of the bulk-electron temperature and $K\ensuremath{\alpha}$ yield are strongly correlated.