Line emissions from carbon atoms in the divertor plasma

Abstract

We have investigated line emission from carbon atoms in an ionizing plasma for the purpose of diagnosing a divertor plasma in which the electron temperature is high compared to the carbon ionization temperature. We study the temperature and density dependence of the population densities by including the population dynamics of the excited states. The effective line emission and ionization rate coefficients of atomic carbon are computed. The effective ionization rate coefficient increases with density, especially at low temperatures. The radiation power from atomic carbon increases proportionally to the electron density at low densities but saturates for n e > 10 14cm −3. The opacity for the line emission of carbon atoms is estimated.