Participants: J. Barranco, G. Burt, R. Corsini, A. Dexter, H. Garcia, L. Gatignon, A. Gerbershagen, A. Grudiev, A. Latina, Y. Levinsen, E. Marin, T. Persson, J. Pfingstner, Y. Renier, D. Schulte, P. Skowronski, J. Snuverink, G. Sterbini, F. Stulle, Y.W. Wang, P. Zisopoulos
via WebEx: J. Jones
D.S. informed that the planning for LCWS2011 has started.
G.B. presented results of Placet simulations of the BDS with integrated crab cavity. He also discussed the impact of wake fields by the crab cavity on the beam. Incoming beam jitter and cavity misalignment will induce wakes leading to luminosity loss. D.S. will provide better input on static and dynamic beam jitter.
J.J. discussed the optimisation of the BDS including the crab cavity.
A.D. presented the crab cavity development and optimisation. He discussed issues and mitigation strategies. After the presentation it was discussed how large the incoming beam offset could become. D.S. said the static offset will be small but dynamic jitter could reach up to 0.4mm.
J.B. discussed possible reasons for the observed luminosity loss when the crab cavity is being used. Since the crab cavity is located in front of strong sextupoles the beam rotation, which is induced by the crab cavity, will lead to slightly differenct focusing of beam head and tail. At the IP this leads to a travelling focus and luminosity loss can occur in case the focusing is wrong, i.e. if the sign of the rotation angle is wrong. This effect should be taken into account for the layout of the BDS and the choice of the crossing angle.
There are minutes attached to this event.
Show them.