Funneling with the two-beam RFQ

Abstract

By ion beam funneling the beam current can be multiplied without changing the emittance, which is proposed for new high current accelerator facilities like HIDIF or ESS. There the required beam current can not be produced by a single pass rf-linac. The increase in brightness in such a driver linac is done by several funneling stages at low energies, in which two identically funneling studies, are not necessary [1,2,3]. A short r.f. funneling deflector is placed at the beam crossing position behind the RFQ. The HIDIF linac starts with 16 times 3 ion sources for three different ion species to allow socalled "telescoping" at the final focus [5]. With four funneling stages the frequency has been increased from 12.5 MHz to 200 MHz accordingly [6]. bunched-ion beams are combined into a single beam with twice the frequency, current and brightness.Our funneling experiment is a setup of two ion sources, a two beam RFQ, a funnel deflector and beam diagnostic equipment to demonstrate funneling of ion beams as a model for the first hneling stage of a HIIF driver. The progress of the funneling experiment and results of simulations will be presented.

The Frankfurt Funneling Experiment

“…The emittance from the beamline with the matching section reduces the beam radius. The measurements are in good agreement with our simulations shown in figure 8 shown that funneling can be done [7,9], but the beams…”

“…For beam bending to a common axis we use two types of deflectors, the single and the multi cell funnel deflector [7]. The multi cell deflector allows beam bending at lower voltages in the bending gap.…”

Simulations for the Frankfurt Funneling Experiment

“…The Frankfurt Funneling Experiment consists of two multicusp ion sources, a Two-Beam RFQ accelerator and a funneling deflector to bend both beam lines to a common beam axis [1,2]. The principle of funneling is displayed in fig.…”