Ion beam focusing by radial electron flows

Possibility is studied for use of the radially convergent tape electron beams with a view to neutralizing the volumetric charge and focussing the ion beam in the system formed by the cylindrical grounded spiral and tungsten filaments drawn in parallel with the spiral generator. Upon application of the negative potential the filaments inject the electrons. The metal cylinder kept at the same negative potential precludes radial rejection of the electrons from the system. The deuteron beam with the energy of 50 MeV is fed from the source through a transparent current transducer and collimating diaphragm into the system, after which it is precipitated on the collector. Since the spark-type source has the spreading of the current amplitude, the average value of the current in 100 pulses has been measured. The measurement results indicate the increase of the current flow with the increase of the filament channel current and negative bias