SEMINARS - Mini-Workshop on SPS Scrubbing Run Results and Implications for the LHC

by (CERN)

Friday 28 Jun 2002, 09:00 → 17:00 Europe/Zurich

LHC Auditorium (CERN)

When operated with LHC-type beams, the SPS machine operation is perturbed by the electron cloud phenomenon which induces beam instabilities and pressure rises. This phenomenon is also a major concern for the LHC as it could induce additional heat load to the cryogenic system and beam perturbations at injection energy. To improve the understanding of the electron cloud mechanism, to crosscheck the simulations made for the SPS and LHC and to validate the scrubbing scenario proposed for the commissioning of the LHC, a 12th days scrubbing Period in the SPS with high intensities and a high duty cycle took place in May. This mini-workshop will present the results obtained with several detectors installed in the SPS machine to measure: the electron cloud build up, the vacuum pressure rises, the in-situ secondary electron yield measurements, the heat load measurements in warm and cold surfaces, the NEG coating behavior. Comparison between the electron cloud simulations and measurements will be made. Regarding to beam dynamics and instabilities, measurements on the emittance preservation, observations in the longitudinal plane and interaction between the electron cloud and the machine impedance will be shown. All these measurements will be compared to the simulations of beam dynamics made for the SPS. Finally, the improvement of the transverse damper system and the set-up and adjustments of the RF system for the high intensity LHC Beam will be addressed.

Organiser(s): SL and LHC Divisions