Evolution of indirect-drive-implosion core electron temperature determined by time-resolved X-ray Ar K-shell spectroscopy

Time-resolved X-ray spectroscopy has been used to study the implosion physics of indirectly driven inertial confinement fusion experiments on the SG Ⅱ laser facility. Through the use of high-Z dopants (Ar) in D2 gas, K-shell emissions, which provide information on core conditions, were recorded by streaked X-ray crystal spectrometer. Evolution of core electron temperatures was then deduced by comparing the line intensity ratio of the Heα to Lyα resonance lines inferred from experiments with that obtained by theoretical calculations, and self-absorption effects are corrected by the escape factor. The results show that this method for electron temperature diagnosis is not sensitive to the variation of electron density, and the Heα and Lyα lines are optically thin in current experiments.