Subnanosecond Chopper-Buncher System for Heavy Ions

A chopper-buncher for a 14UD Pelletron is being assembled and tested. The system was designed to produce heavy ion bursts of approximately 100 ps at 15% transmission. This system will be used for nuclear physics fast timing experiments and can also serve as an injector to a linac. The ion source beam is sliced by a deflector-redeflector chopper operating at 1.68 MHz. The chopper is followed by a 3rd harmonic corrected buncher, which produces bunches of less than 1 ns duration at the target area, for ions up to mass 60. Further bunching, down to 100 ps, is accomplished by a superconducting cavity operating at 430 MHz.