K-shell spectra of a laser-produced carbon plasma have been measured and analyzed. A graphite plate was irradiated by a 2.1ns ultraviolet laser pulse, and the radiated X-rays were measured with a flat-field grating spectrograph. The recorded lines have been identified as hydrogenic Lyman series 1s-np and heliumlike transitions 1s<sup>2</sup> -lsnp (n=2-4). The measured wavelength and the spectral resolution of the flat-field grating spectrograph were calibrated by utilizing those lines. Hydrodynamic simulations and calculations of charge-state distributions in the local thermodynamic equilibrium (LTE) regime were carried out to interpret the K-shell spectra.
Laser drive ramp compression is an important way to achieve extremely high pressure but relatively low temperature material state. This article introduces our progresses in recent years. The main progresses contain theoretical researches and experimental researches. In theoretical part, an analytical model for designing driving pressure pulse was set up, and a new characteristic method based on a Murnaghan-form state equation was developed. What’s more, X-ray preheating in the target and laser pulse design in laser-indirect-driven experiments were studied. In the experimental part, laser-direct driven experiments and laser laser-indirect driven experiments were performed on aluminum and iron, results showing the experimental design methods were feasible, and the compressions were in isentropic ways.