Interpretation of Observed Impurity Radiation in a Discharge of the C-Stellarator

Abstract

Measurements of absolute intensities of the resonance multiplets of oxygen ions in a typical discharge of the C‐Stellarator are employed to deduce the ion concentrations as a function of time. The analysis of the data is based on an idealized model in which electron temperature and density are uniform both radially and axially. Electron temperatures are found from relative intensities of some of these multiplets, and compared with temperature computed from the electrical conductivity. Mean particle confinement times are deduced from the time behavior of the concentrations of highly ionized oxygen. From these confinement times, and the observed electron density changes, the particle influx rates are obtained. The total power loss by radiation is evaluated for the uniform model. The radiation by oxygen ions, which is explicitly nearly independent of temperature, and the ionization and heating of hydrogen influx, which is nearly proportional to temperature, are found to be the dominating mechanisms of power loss.