H-Beam Operation of TrdE IUCF Stripper Loop

The design and development using a 0.62 MeV molecular hydrogen beam for injection of a low energy proton storage ring to enhance the brightness and vary the rf microstructure of the beams from the IUCF cyclotrons were previously reported.1,2 The performance of the device, called a "stripper loop", is limited by the stripping properties of the H2+ ion and by the resulting low energy (0.31 MeV) of the circulating proton beam. However, peak bean intensity gains of nearly 6 were obtained. Larger beam intensity gains are predicted when the stripper loop is injected with 0.62 MeV H- ions. In recent development studies using an H- beam for injection, brightness gains of nearly 11 were obtained for proton beam energies of 180 and 200 MeV with pulse periods of about 2 μS. The modifications required to inject H- ions into the stripper loop and the results of the beam development studies are presented and compared with theoretical predictions.