Atomic Spectroscopy for Applications in Energy Technology

Sammanfattning: This thesis intends to provide spectroscopic information which may be of use in the investigation of low-density plasmas. Developed since the 19th century, the spectroscopic approach has proven to be a versatile method for measuring properties in hot gases, such as electron and ion temperatures and densities, the abundance of various elements in the gas, etc. However, such investigations rely on knowledge in the atomic structure of the various constituents of the plasma, and the mechanisms behind the interaction between atoms and ions, and radiation. Thus, the papers discussed in this thesis focused on different areas where parameters obtained by atomic spectroscopy might prove useful. The applications, so to say, have been in the field of energy production and consumption. The first project involved time-resolved spectroscopy of the cathode region of a fluorescent lamp. The information may be useful to understand population processes in low-density plasmas in general, and plasmas in fluorescent lamps especially. The second and third projects have investigated tungsten ions. Tungsten is planned to be used as plasma facing wall material in the fusion reactor ITER, currently under construction in France. The material is expected to be injected into the plasma due to sputtering, where it is later ionized. Project 2 measured the spectrum of W II, which is likely to exist in the outer, colder parts of the ITER plasma. The ions were created and excited by a Penning discharge lamp and recorded by a Fourier Transform Spectrometer at Lund Observatory. The line intensities gave, through the method of branching fractions and lifetimes, absolute transition probabilities for 95 transitions in the ultraviolet and the visible part of the spectrum. Project 3 measured the wavelengths in the EUV for Co- through Mg-like W, i.e. highly charged ions expected to occur in the inner parts of the ITER plasma. The ions were generated and excited through an electron beam ion trap at the Lawrence Livermore National Laboratory.