COLLISIONAL-RADIATIVE MODELS FOR HYDROGEN-LIKE AND HELIUM-LIKE CARBONAND OXYGEN IONS AND APPLICATIONS TO EXPERIMENTAL-DATA FROM THE TS TOKAMAK AND THE REVERSED-FIELD PINCH RFX

Collisional radiative models (CRM) are needed to simulate experimental line brightnesses and emissivities from fusion devices. CRM are built for H-like and He-like carbon and oxygen ions, following a detailed r eview of the published literature on the required atomic data (includi ng both collision rate coefficients and atomic transition probabilitie s). The impurity ion radial distribution is obtained using a transport code with two radius dependent transport parameters: a diffusion coef ficient D and an inward convection velocity V. Reliable atomic data ar e a prerequisite to these simulations, since they are supposed to be w ell known; adjustement of the simulations to the experimental line and /or continuum brightnesses and emissivities is done by varying only D and V. Examples are given of the quantitative interpretation of experi mental spectroscopic data from two fusion devices: the Tore Supra Toka mak and the Reversed Field Pinch RFX. As a consequence of the order of magnitude difference in the central electron temperatures in the two devices, the sensitivity of the H-like and He-like ion emissions to th e transport parameters is different. These differences are highlighted in the examples given.