The Researcn About Spectral Characteristics Of Highly Charged Aluminum Ions Produced By Laser Ablation

To research the spectra characteristic of highly charged ions have a very important influence in the theoretical study on the atomic structure, as well as make a solid foundation of theoretical and experimental for the research and diagnosis on kinds of plasmas in astrophysics and fusion.The laser produced plasma technique is a important, unique and effective diagnostic tool for highly charged ions spectroscopy and has been successfully used for the study of of low, intermediate and high ion stages.In this thesis, the main work is divided into two parts:(1) The highly charged Al ion widely present in the atmosphere, solar spectra and stellar spectra.The emission spectrum of Al plasma in wavelength range of 23-35 nm is obtained using the double-pulse laser produced plasma method, it’s found that the emission lines in the experimental spectrum arise from the 2s-2p transitions of A15+-A18+ions. Based on a steady-state collision radiation model and the assumption of a normalized Boltzmann distribution among the excited states, the populations of aluminium ions mentioned above have been estimated by choosing the different plasma parameters, such as plasma temperature and electron density. Finally, the optimum plasma parameters have been obtained by comparing the experimental spectra with simulated ones under the different plasma temperature.(2) Based on the local thermal balance radiation transport equation, a computer program have been completed, and the theoretical computed results have been simulated by using the program. Furthermore, in order to make this program is more reliable to the laser produced plasma spectrum in a vacuum, especially for the high charge state, these codes have also re-optimized according to the theory methods. At the same time, the plasma emission spectra of Al ions have been simulated with use of these codes, and the expansion speed of the plasma boundary, the temperature, the electron number density and the variation trend of spectral radiance have been identified at the different spatial-temporal.