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 670nm, 610nm and 460nm have been chosen. The overall range of ne and Te in ICWC plasmas measured with the Li beam is 1016m−3 to a few 1017m−3 for the electron density and 1.5–15eV for the electron temperature. With the application of oscillating vertical and horizontal magnetic fields in the range of 0.01T the plasma extends towards the bottom of the TEXTOR vessel, providing a wider distribution of particle fluxes to the vessel walls.