Study of the effect of space charge on the transport of a 2 MeV proton beam in an accelerator based epithermal neutron source

A neutron source comprised of a vacuum insulated tandem accelerator and a solid lithium target is in operation for development of boron neutron capture therapy and other applications. The size of the proton beam on the target surface depending on the proton beam current was measured using an infrared camera and thermocouples inserted inside the target. The absence of a noticeable influence of the space charge on the transportation of the proton beam from the accelerator to the target at a distance of 5 m has been established, which simplifies the operation of the neutron source.