OPTIMIZATION OF THE NEGATIVE HYDROGEN ION BEAM INJECTION INTO THE TANDEM ACCELERATOR WITH VACUUM INSULATION

The beam of negative hydrogen ions is injected into the tandem accelerator with vacuum insulation in order to obtain high-current proton beam. To accurately direct the beam into the accelerator the magnetic focusing lenses are used. In this paper it is described the design of the special beam detector mounted in front of the first accelerating electrode and intended to measure beam profile and the current density. The results of measurements of the dependence of the current density on the power of the magnetic focusing lenses are shown. The parameters of the beam resulting in the best agreement of calculation and experiment are specified. The optimum focusing mode to inject the negative hydrogen ions into the accelerator is determined.