Effects of intense ultraviolet radiation on electrostatic energy analyzers

Intense ultraviolet radiation from the plasma poses a significant problem for the implementation of heavy ion beam probe diagnostic systems on fusion-oriented confinement devices. The radiation enters the electrostatic energy analyzer used to detect secondary ions, resulting in both a distortion of the electric field inside the analyzer and noise generation in the detector channels. Data-acquisition procedures and mechanical design techniques have been developed to significantly reduce these effects. We have also been successful in modeling the electric field distortion and have developed a data correction procedure based on this model. Methods for approaching the problems anticipated in future devices are also suggested.