Lithium ion sources for investigations of fast ion transport in magnetized plasmas

Abstract

In order to study the interaction of ions of intermediate energies with plasma fluctuations, two plasma immersible lithium ion sources, based on solid-state thermionic emitters (Li aluminosilicate) were developed. Compared to discharge based ion sources, they are compact, have zero gas load, small energy dispersion, and can be operated at any angle with respect to an ambient magnetic field of up to 4.0 kG. Beam energies range from 400 eV to 2.0 keV with typical beam current densities in the 1 mAcm(2) range. Because of the low ion mass, beam velocities of 100-300 kms are in the range of Alfven speeds in typical helium plasmas in the large plasma device.