Experience Gained in the SPS for the Future LHC Abort Gap Cleaning

Abort gap cleaning using a transverse damper (feedback) has been previously shown in the RHIC accelerator [1]. We report on experimental results in the SPS [2], where the transverse damper was used to excite transverse oscillations on part of an LHC test beam and, by the induced losses, to create a practically particle free zone. It is proposed to use the same principle for abort gap cleaning in the LHC. For the LHC accelerator, abort gap cleaning may be required at injection energy, during the ramp and at top energy [3]. The transverse excitation can be optimized taking into account the actual bandwidth of the damper systems and the possibility to fully modulate their input signal to match the beam betatron tune distribution.