Characteristics and Transport of a Proton Beam Generated in a Linear Induction Accelerator

A seven Ohm Blumlein has been used to generate a proton beam in an induction linac using a single magnetically insulated accelerating gap. The proton beam generated has an energy of up to 1.3 MeV at 4.0 kA and a pulse duration of 50 nsec. In this paper we report measurements of the beam characteristics and beam transport. Lack of complete neutralization was apparent and a modified system which relies on collective focusing of the ion beam by an electron cloud in an axial magnetic field has been developed. First results obtained using the collective focusing show evidence of improved transport over, at least, short distances. Further measurements are needed to confirm the adequacy of the present system for transport over the scale lengths needed for a multi-gap accelerator.