Collisional-radiative modeling and radiative emission of tungsten in tokamak plasmas in the temperature range (800–5000) eV

Abstract

We present new collisional-modeling calculations of tungsten plasmas at electron density of about 5 × 1013 cm−3 and for electron temperatures in the range 0.8–5 keV. These conditions are relevant to current tokamaks. In this temperature range, the modeling of the ionization balance and of spectra is a long-standing problem. Addressing this problem is also useful for plasmas that will be produced in the future tokamak ITER. In particular, we discuss the problem of ensuring completeness of the list of configurations included in the calculations. We also discuss comparisons of experimental measurements in the EUV range performed in the WEST tokamak with synthetized spectra based on the use of the unresolved transition array and of the spin–orbit split array formalisms. While this work does not rely on a precise identification of detailed lines, modeled spectra display emission features that looks quite similar to the experimental spectra. A conclusion is that standard calculation methods used for the evaluation of the configuration average collisional and radiative rates, are fine provided that a convenient list of configurations is used in the calculations.