Single-gap multi-harmonic buncher for NSC pelletron

A single-gap multi-harmonic buncher, developed in collaboration with Argonn e National Laboratory, has been installed in the pre-acceleration region of NSC Pelletron. This buncher is required for injecting bunched beam into th e booster LINAC, presently under construction. A saw-tooth voltage generate d across a single gap formed by a closely spaced pair of grids is used for bunching the de ion beam produced by the Pelletron accelerator. This saw-to oth voltage is produced by adding a sinewave with its three higher harmonic s in proper phase and amplitude. Si-28 beam has been bunched successfully u sing this buncher. The best FWHM of the bunched beam was 1.5ns and the maxi mum efficiency of bunching was 50%. The bunching voltage had no steering ef fect on the beam.