Participants: 
A. Abramov, K. André, P. Arrutia, M. Boland, C. Bracco, C. Carli, Y. Dutheil, T. Kramer, A. Lechner, P. Martinek, G. Roy, A. Vanel, S. Yue

FCC top-up injection with thick septa (S. Yue)

• A new injection lattice is found to use magnetic septa (thicker)
• Possible optimization for injection
  • Reduce horizontal size of injected beam (emittance H/V exchange or just horizontal optics)
  • Decrease energy spread to fit in the DA longitudinal bucket controur
• Stripline kicker is used to produce a one turn fast bump (304 us),
  • Rises and falls in the abort gap
• New optics needs evaluating
  • optics repo features CI to compute DA, G. Roy can be contacted about this
  • Sen to create a new branch and update the lattice with injection optics
• longitudinal parameters
  • Presently longitudinal parameters matched to the collider equilibirum are not optimal for on-axis injection
  • Booster beam need to fit the collider injection requirements
  • Needs to be discussed with the booster and RF teams
• Machine protection concers
  • Will be oversaw by Chiara
  • Present concept is to split the maximum Booster load into 10 cunks, separated by 100ms
  • 1/10th of maximum Bosster current may be absorbed by a collimator
  • If the booster maximum current was reduced by 10, there could be benefice to the booster design
• The circumference of collider and booster should be same
  • Kevin will check with Frank and Antoine to ensure this is agreed
• Based on present lattice in booster ring, the SR is not considered
  • In tt operation mode, the beam will lose ~ 10% energy in each turn
  • For tapering, the magnet in arc will be ramped up/down at different levels for e+/e-
• PB integration
  • will contain booster->collider transfer
  • Also contains collider dump and investigating beam dynamics and positionning to reuse it for the booster dump
  • Distance beamline-dump needs to be reviewed (S. Yue)

Full energy booster systems timeline (Y. Dutheil)

• The deadline for FCCIS report on booster design is June 2024 
• There are collider/booster dump, collider injection and booster extraction systems in straight section (PB)
  • Need more discussion about integrated systems and related transfer lines
  • The transfer line between booster extraction and collider injection is ~ 200m.
  • Upload the injection lattice to the repository to check the feasibility of system integration

Discussion

• CLS linac upgrade
  • Present schedule aims at beam commisioing in the later part of the summer
  • CERN colleagues are invited to join the beam commissioing of the new linac
• P. Hunchkak continuing PhD on MAD-NG modelling of RDTs for FCC with ABP team