Better Dynamic Closed Loop Control of the PSB RF Accelerating System

The introduction of pulse-to-pulse modulation1) (PPM) in the Proton Synchrotron Booster (PSB) requires that a large number of settings be changed on a pulse-to-pulse basis, imposing a very heavy load on the control system and the operators. Many systems, originally not designed for this type of operation, have to be modified either to accept new settings every cycle (values to be adjusted by the operators, switching to be performed by the control system), or to be self-adaptive, i.e. automatically adjusting to the required conditions. The second approach seems preferable, if feasible without excessive increase in complexity or decrease in reliability. In some cases it was actually possible to reduce the complexity and increase the reliability. This paper deals with the modifications in the beam control system. While reviewing the system´s design, additional improvements were found to be possible at moderate cost: they were also, or will be, introduced, and are mentioned accordingly. Mention is made also of a relatively simple method of longitudinal stabilization which has been tested at the PSB.