Control of longitudinal instabilities in the LEB

The potential longitudinal instabilities and their control in the SSC Low Energy Booster are examined. Coasting beam theory shows there is a chance for microwave instabilities at the end of the acceleration period for the maximum design current of 0.5 Adc. The beam is stable to microwave instabilities for the Collider fill current of 0.1 Adc. Single bunch instabilities driven by the RF cavity accelerating mode will be stabilized by beam phase, voltage amplitude, tuner bias and RF feedback loops. The coupled bunch instabilities driven by the cavities´ higher order modes and ether resonant structures appear to represent the biggest challenge to longitudinal stability. A broadband passive damper on each RF cavity will greatly decrease the chance of any coupled bunch instabilities although other options to aid the damper are investigated. The control of longitudinal instabilities in the LEB appears feasible and should not limit its operation up to the peak design intensities