A Fast Chopper for Intensity Adjustment of Heavy-Ion Beams

Several heavy-ion accelerators are being developed worldwide. It is desirable to provide simultaneous beam delivery to multiple users that can be efficiently implemented using a combination of rf-sweepers and DC magnets. A fast chopper can be used to modulate cw beam intensity by chopping away individual bunches at low beam energy. The major issue of fast choppers is the excessive power requirements from the voltage pulsers. By providing high wave impedance, ∼ 200 Ohm, of a traveling wave structure one can reduce the power requirements for the fast voltage pulser. Several design options of high-impedance structures are discussed.