A novel design for heavy ion beam funnelling

In heavy ion inertial fusion (HIIF) injectors the current accumulation is done by beam funnelling. A novel scheme for an r.f. funnelling deflector operating at low voltages has been developed. With the use of convergent incoming beams a short structure placed around the beam crossing position seems to be possible. The design of the multigap deflector geometry and the results of particle simulations together with r.f. structure development will be discussed. The experimental set-up for a combination of a two-beam radio-frequency quadrupole (RFQ) with such a deflector for funnelling of two He + beams at low energies will be presented.