PROPOSAL FOR A NOVEL 2-BEAM ACCELERATOR

A new configuration is proposed wherein a low-current beam is accelera ted to high energies (tens of amps, tens of MeV) by a driver beam of h igh current and low energy (a few kiloamps, < 1 MeV). The annular driv er beam excites the TM020 cavity mode of an accelerating structure whi ch transfers its rf power to the on-axis secondary beam. Systematic va riation of the driver beam radius provides the secondary beam with pha se focusing and adjustable acceleration gradient. A proof-of-principle experiment is suggested.