Determination of the electron temperature profile in a laser plasma from relative populations of the levels of hydrogen-like ions

A method is proposed for determining the electron temperature of a laser plasma from the relative intensities of optically thin Lyman- or Balmer-series spectral lines of hydrogen-like ions. The method involves selecting the electron temperature corresponding to the experimentally observed ratios of the level populations of hydrogen-like ions. Independent measurements of the electron density and plasma ion composition, and also theoretical calculations of the level populations, are used. Measurements are reported of the electron temperature profiles in a laser plasma at distances of 25–1400 μ from the target using spectra of C VI, O VIII, and F IX ions.