Space charge effects in the SSC low energy booster

The SSC linear accelerator

“…Negative hydrogen ions are accelerated so that 4-turn charge changing injection can be used in the Low Energy Booster [4] (LEB) to minimize emittance growth during the injection process. The energy and fundamental rf frequency of 428 MHz are chosen to make emittance growth due to space charge as small as possible in the linac, to make space charge tune shift at the start of the LEB cycle [5] manageable, to maintain the option of bunch-to-bucket transfer into the booster synchrotron by having an integer relationship between the linac rf eequency and that of the LEB at injection, and to allow use of klystrons, rather than gridded tubes in the rf supplies. Sufficient space has been provided in both the tunnel and the rf gallery for the additional equipment needed to increase the linac energy, if that route to higher luminosity is chosen.…”