Measurement of Electron Densities and Temperatures in the Plasma Boundary Combining Neutral Beam Probes and Laser-Induced Fluorescence

A new diagnostic method using both techniques of neutral beam probing and laser-induced fluorescence (LIF) is proposed to measure electron density (1011-1013 cm-3) and electron temperature (1-100 eV) of a boundary layer plasma in devices like tokamaks. The local electron density can be obtained by measuring the photon flux of the resonance line produced by electron impact excitation of an injected neutral Li-beam which is produced by laser-induced evaporation (LIE). The density of the neutral Li-beam which is necessary for the determination of the electron density is measured by LIF. The local electron temperature can be obtained by determining the attenuation of two neutral beams (Li, and Al or Ti) produced by LIE, of which the measurements are carried out by means of LIF. The applicability of this method to the TEXTOR tokamak is discussed in detail.