Electron density and temperature measurements in TEXTOR ion cyclotron wall conditioning plasmas by thermal Li beam spectroscopy

In this contribution, we report on the application of Li beam emission spectroscopy to determine electron density and temperature in ion cyclotron wall conditioning plasmas with the help of a collisional-radiative model. Intensity ratios of atomic line emission at 670 nm, 610 nm and 460 nm have been chosen. The overall range of n_e and T_e in ICWC plasmas measured with the Li beam is 10¹⁶ m^-3 to a few 10¹⁷ m^-3 for the electron density and 1.5-15 eV for the electron temperature. With the application of oscillating vertical and horizontal magnetic fields in the range of 0.01 T the plasma extends towards the bottom of the TEXTOR vessel, providing a wider distribution of particle fluxes to the vessel walls.