A NEUTRAL LITHIUM BEAM SOURCE FOR SMALL TOKAMAK DIAGNOSTIC

In this paper a neutral lithium beam source for small Tokamak diagnostic is described. In the source, lithium ions are extracted from a heated emitter (β- Eucryptite), focused by a electrostatic lens, and neutralized in a charge -exchange cell by sodium atoms. Finally passing through an ion deflection system a neutral lithium beam is obtained. The beam can be pulsed from ten to hundred millisecond. The dependence of the beam current on the parameters is investigated at the beam energy of 6keV. The neutral beam equivalent current obtained is typically 20μA/cm², the beam FWHM being about 8-9mm. The source will be used for measuring plasma parameters in the edge-range of HT-6M Tokamak device.