First EIRENE modelling of a He plasma. Simulation of emission profiles in a TJ-II ECRH plasma

Introduction The emission profiles of the three neutral He lines typically used in the supersonic He beam diagnostic were recently recorded in ECRH helium plasmas of the TJ-II stellarator, with minor contamination from H [1]. In the present investigation the Eirene code [2], which we had previously adapted to the fully 3D TJ-II geometry, has been used for the first time to obtain He emission profiles, and its predictions have been compared with the line integrated values measured at the plasma edge. While the central values of the density and temperature profiles corresponding to the Thomson Scattering data for the analysed discharges have been used in the simulation, some freedom on the corresponding values at the edge has been allowed, and the values measured in similar H plasmas by the supersonic He beam have been used as starting guess. For these simulations the original Eirene default set of reactions has been completed with the He emissivities at the selected wavelengths and with CX processes for He.