participants : H. Bartosik, C. Carli, Y. Dutheil, G. Nigrelli, T. Mori, P.Raimondi, K. Skoufaris, S. Yue

• BSC and impact on the bump amplitude for conventional injection
• Stay-clear definition is linear sum of beta and disp primary cut, may become larger with errors
• Need to add the distance in stay clear- distance
• Question of the local bump during injection at the collimator,
• could we instead place such collimator closer to the septum
• There will anyway be an absorber there and can be adjustable
• Important to estimate the number of particle that would hit this collimator
• An increase to the bump amplitude should be established to account for margin, which should be coming from collimation
• Also errors should be considered as it may diverge considerably
• Non linearities for instance through non-linear dispersion can be obtained with twiss
• Ttbar mode
• Using a guess on the momentum cut, final numbers need collimation input
• Question of keeping bump height constant for every mode, take the max
• Or keep a lower bump at Z-mode and use the 4 dipoles used for dispersion to adjust the closed orbit. And we don't need to use movable septum
• Should be considering pi bump and minimize the bump amplitude
• Pi bump has optics constraints, and other concerns
• Other concerns about non closure are in vertical due to tilt or optics. Compensated with skew quads in the bump at ESRF
• Still need to see the implication of 2 Vs 4 kickers
• Pi bump also causes non-closed dispersion bump, which is significant at ESRF and would need to be considered carefully
• The consideration on the bump amplitude shouldn't only be about local closure but also back-propagate from the IP
• Make an updated sketch about bump height and share this with the working group for discussion
• Important to establish a TODO list, or priority list
• Question of the failure cases
• What number to share, and highlight the physics that is included
• From Giulia With bare lattice it is 100%, with BB 90% and with collimation reach 87%
• With errors and beam-beam, efficiencies are somewhat lowers but this is a work in progress
• Kyriacos is also working on some aspects which should be discussed