Exploring LHC Long-Range Beam-Beam Compensation in the SPS

by Frank Zimmermann (CERN)

Thursday 29 Apr 2004, 11:00 → 12:00 Europe/Zurich

864-AB Auditorium- (CERN)

The ultimate performance of the LHC will likely be limited by long-range collisions between the two counter-propagating proton beams. Up to 120 such collisions will occur in the common beam pipes around the 4 primary interaction points. Both simulations and experience from Tevatron Run-II predict that the long-range collisions can degrade the beam stability and reduce the so-called 'dynamic aperture'. As a countermeasure for the LHC, a compensation scheme based on electro-magnetic lenses ('wires') was proposed. Since 2002 a first prototype wire in the SPS mimics the effect of LHC long-collisions. A dynamic shaving of the SPS beam was observed, consistent with expectation. Its dependence on beam-wire (or beam-beam) distance and wire (or beam) current was explored. In the 2004 SPS run, two additional and novel wire devices will address the practicality of the proposed compensation, and, in particular, reveal the pertinent tolerances. This presentation will describe the experimental set up in the SPS, highlights from the 2002-2003 SPS machine studies, and the plan for 2004.

Organiser(s): Werner Herr (AB/ABP)
More information: http://cern.ch/AB-seminar/

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