Algorithm-based modeling of fractional ion abundance and rates of ionization and recombination for tungsten plasmas

Sasaki, Akira; Murakami, Izumi*

The fractional ion abundance and rates of ionization and recombination of multiple charged tungsten ions in magnetic fusion plasmas are investigated using a collisional radiative model. Using a computer algorithm to generate a complete set of atomic states to be included into the collisional radiative model, the level population and ion abundance are calculated taking a sufficient number of dieletronic recombination and excitation autoionization channels into account. The atomic data, such as energy levels and rates of radiative decay as well as autoionization are provided from the ab-initio calculation using the HULLAC. The ion abundance is shown to converge with respect to the size of the model in the temperature range of 100 eV to 5 keV, and the ratio between the abundances of W and W ions agrees well with an experimental result obtained without any artificial adjustment of atomic rates.