Diagnostic of laser induced Li II plasma

摘要

Spectral line broadening in dense plasmas is investigated for lithium He-like ion based on a microscopic quantum-statistical approach. By using thermodynamic Greens function, perturber-radiator interaction, plasma correlation and screening effects are taken into account. Ions are treated in quasi-static approximation, leading to a Stark effect by the surrounding perturbers microfield. Stark broadening of Li II (2p3P2;1;0?2s3S1) 548 nm line is calculated, plasma parameters such as temperature and free electron density for the expanding Li plasma after 60 ns from laser irradiation are analyzed ( Doria, D., Kavanagh, K.D., Costello, J.T., and Luna, H. (2006) Meas. Sci. Technol., 17, 670-674). The estimated spatial electron density and temperature ranges are ne = (0.25?2)×1024 m ?3 and T ≈ (2?3.5) eV, respectively. The dependence of plasma parameters on the line width is investigated. A good agreement is shown by comparing our calculation with thepublished measured profiles.