Operation and upgrade of diagnostic neutral beam injector RUDI at TEXTOR tokamak.

The status and the executing modernization of RUssian Diagnostic Injector (RUDI) are described. The ion source consists of arc plasma emitter and multiaperture four-electrode ion optical system. The present ion optical system with round beamlets is to be replaced by new slit apertures system for the reducing beam angular divergence in one direction. Due to enlarged dimensions and transparency of new ion optical system the extracted ion beam current will be by 50% increased. For the extension of beam pulse duration from 4 s to 8-10 s an optimized metal-ceramic arc-discharge channel is introduced. In the paper, the optical measurements results of beam parameters, including the profile of species distribution, scanned by custom-built multichannel spectroscope, are also presented.