Highly Charged Ions And Neutral Atomic Spectroscopy,

This paper includes three parts: the experimental and the theoretical studies for intercombination lines in highly charged ions(HCI), and the experimental study on spectra of neutral atoms in florescent light tube.The study on the relevant physics of HCI is a new subject. It is not only very important for the study and test of atomic structure, nuclear structure, theory of relativity, quantum electrodynamics(QED) and elementary interaction but also very crucial for the study of astronomy and plasma diagnostics. Since an intercombination line is directly caused by the mixing of states and theoretical transition probabilities are very sensitive to the quality of the wave functions used, the energy separation between the interacting states must be accurately represented. Calculations of these rates by ab initio methods require careful treatment of several factors, including electron correlation and spin-orbit interactions. Experimental studies of intercombiantion rates thus provide very stringent tests of atomic structure calculations. And the relative strength of many forbidden lines are effected by the plasma temperature and electron density. So the energies of intercombination transitions are needed for the diagnosing astrophysical and laboratory plasmas.The first two parts concentrate on the wavelength for n=3, An=0 intercombination lines. In two recent publications for the 3s²3p²3P₁.2 -3s3p³5 S2 transitions in Si I sequence, quite different iso-electronic developments were reported for these two transitions. Both of these trends were supported by data obtained using similar methods, i.e. beam-foil spectroscopy(BFS). And the two reported trends indicate quite different wavelengths for the above transitions and both of them clearly differ from the newer calculations by Ishikawa. On this background we put our interest in the Si-like RhXXXII ion. Firstly we also used the methods of BFS to obtained the wavelengths of the 3s23p23P1,2 -3s3p35S2 intercombination lines, however, we have used a CCD detector system to greatly improve signal/noise ratios. Secondly we used the Grasp (General purpose Relativistic Atomic Structure Package ) of MCDF method to do some calculations on the 3s23p23P1,2 -3s3p35S2 trantsitions...