Investigations Of The KeV X-ray Spectroscopy Of Laser-Produced Plasmas

The X-ray spectra emitted from laser-produced plasmas contain plentiful information. It is a powerful tool to carry out plasma diagnosis and to study the formation and evolution of the plasmas as well. It plays a significant role in the field of inertial confinement fusion. In this paper, the atomic physics mechanism, emission , absorbing and the time-dependent evolution of the KeV X-ray spectra are studied in details both experimentally and theoretically.Firstly, the structures of the highly-striped ions that emit or absorb X-ray are investigated, and a method for calculating the relativistic configuration-averaged energies basing on the multiconfigurational Dirac-Fock model and configuration averaging is presented. According to this method, the regular changes of the energy splitting occurred in highly-charged ions are carefully studied, and analytically fitted formulas for calculating the subconfiguration-averaged energies of high Z elments are given.Secondly, a theoretical model for simulating the the emission and absorbing of X-ray are established basing on the stable collisional-radiative equilibrium and the local thermodynamical equilibrium model. Moreover, time-dependent characteristics of the X-ray spectra emitted from laser-produced Al plasma are modeled by coupling an one-dimensional radiative hydrodynamics code with this spectral model.Finally, some issues related to the experimental measurements of the KeV X-ray,such as the diffractional efficiency of crystal, the geometrical factor and the film response, are discussed. Furthermore, time-resolved and space-resolved high spectra resolution measurement systems are set up and used to measure the K-shell emission of the laser-produced Al plasma and the M-band emission of the laser-produced Au plasma respectively. Using the measured spectra, studies on the diagnosis of the electron density and electron temperature of the plasmas are also carried out.