Neutral beam injection system for the CAT experiment

In the Budker Institute, the CAT (Compact Axisymmtric Toroid) experiment is being prepared for obtaining a plasmoid with high diamagnetism in axially symmetric magnetic field. Reverse of magnetic field in the plasmoid is also possible in this experiment. The experiment is based on injection of powerful focused neutral beams with extremely large neutral power density in the plasma. Two neutral beam injectors with the energy of hydrogen atoms of 15 keV will be used in the experiment. The neutral beam power of each injector is 2 MW, pulse duration is 5 ms. In the ion source of the injector, plasma emitter is produced by plasma jets from four arc plasma generators. Proton beam with current up to 170 A is formed by multi-slit three-electrode ion-optical system with ballistic focusing. Measured angular divergence of the formed beam along the slits is 10 mrad, divergence in the direction across the slits is 35 mrad. The injector is equipped with a neutralizer, bending magnet, residual ion dump, calorimeter, high speed pumping system with titanium arc evaporation. (author)