X-RAY AND VUV OBSERVATIONS OF MO23-MO33+ BRIGHTNESS PROFILES FROM ALCATOR C-MOD PLASMAS()

Brightness profiles of x-ray and vuv lines from eight molybdenum charg e states between Mo23+ and Mo33(+) have been measured in Alcator C-Mod plasmas. These spatial profiles agree very well with those predicted by a model which includes ionization, recombination, excitation and tr ansport. Comparison with the profiles of many different charge states provides severe constraints upon the rates used in the model. The char ge state density profiles are calculated using measured impurity trans port coefficients, measured electron density and temperature profiles and newly calculated ionization and recombination rate coefficients. T hese new rate coefficients include direct collisional ionization, exci tation-autoionization, dielectronic and radiative recombination. Excit ation-autoionization is shown to be an important process, since the ex cellent agreement between the measurements and predictions is obtained only with its inclusion. Fits to newly calculated excitation rate coe fficients for the transitions are also presented.