Dielectronic 3l4l′ Na-like satellites to Ne-like krypton resonance lines

Transitions from the doubly excited 2s22p53l4l′ and 2s2p63l4l′ levels of Na-like Kr25+ were observed in spectra from plasmas produced in laser-irradiated gas-puff targets. These transitions produce satellites to n = 3–2 and n = 4–2 Ne-like Kr26+ resonance lines. High-resolution x-ray spectra were measured with a relative uncertainty of ±0.001 Å by means of a spherical crystal spectrograph. A simple kinetics model was successfully used to model the experimental spectra, to assist the line identification, and to demonstrate the potential of these lines for diagnosing the plasma conditions. In addition, contributions of these lines to x-ray spectra should be taken into account in the analysis of n = 4–2 Ne-like linewidth diagnostics proposed for electron density measurements in compressed inertial confinement fusion plasmas.