Research On SH - PermEBIT Tungsten Spectrum Detection

The increasing demands on energies and deteriorating environment problems necessitate new kinds of clean and efficient energy sources. One promising solution is fusion energy. Tokamak is such a kind of device for people to investigate magnetic confined fusion. Tungsten is one strong candidate as plasma facing material in Tokamak. Recently, experimental investigation on tungsten is a heated research area.For the merits of its tunable and quasi mono-electron beam energy, Electron Beam Ion Trap (EBIT) is a powerful tool for producing and trapping specific-charged ions. It is therefore an excellent tool for studying atomic and molecular and atomic processes in the edge plasma in Tokamak. However, the temperature in edge plasma in Tokamak, especially in the Scrap-Off Layer (SOL), is relatively low. Accordingly, the charge states of ions are not high. For the research purpose of such kinds of plasma, construction of low energy EBIT for producing and trapping low and moderate charged ions is in need. In this doctorate thesis, we mainly focused on3parts of work:1. Construction and adjustment of the low energy SH-PermEBIT. By experiments and adjustment, the beam energy of SH-PermEBIT successfully reaches the250eV, the designed parameter for low energy working-condition. Further improvements extend the beam energy to60eV low, which is a leading effort worldwide. We obtain the spectrums of Ar in experiments with various beam energies.2. Developing the spectroscopic research platform for SH-PermEBIT. By experiments and adjustments, the spectroscopic research platform covering wavelength range from soft X-ray to visible light (5-8000A) is completed. This platform facilitates spectroscopic researches on low and moderate-charged ions.3. Spectroscopic researches on low-and moderate-charged tungsten ions. For the first time, we detected the ground state M1transition (2F7/20→2F5/2) in Ag-like W. The experimental result agrees well with calculated wavelength using MCDF methods. Furthermore, we unprecedentedly detected some M1spectral lines in Cd-like and In-like W. These experimental results also agree well with the theoretical results. Our data complete the spectral database for low-and moderate-charged tungsten ions. Our efforts lay a solid foundation for experimental and theoretical studies on even lower charged tungsten ions. Our work is especially important for investigations on both edge plasma and plasma-wall interaction in Tokamak.