LIU-SPS Beam Dynamics WG E. Shaposhnikova LIU-SPS coordination meeting

General remarks During year - 9 meetings of the LIU-SPS BD WG + extra ones (isolated flanges, HOMs, …) Main topics: – SPS impedance and instabilities – MDs, space charge, e-cloud Main speakers: H. Bartosik, A. Lasheen, J. Varela Minutes taken by H. Bartosik Contributions to the LIU/HL-LHC Day Help from 2 summer students (~4 months) and 3 stagers (~7 months). Looking for schoolchildren for 2016

Achievements of 2015 Further improvement of the SPS impedance model (TW RF): – simulations and measurements in lab – HOMs in the 200 MHz and 800 MHz RF cavities – isolating flanges Impedance reduction of vacuum flanges: new LIU-SPS baseline Particle simulations and measurements of instabilities during ramp for single and multi-bunch beams. Benchmarking of the impedance model Simulation code BLonD: development & optimization Successful scrubbing – new baseline? Space charge and WP choice understanding Nonlinear optics studies First intensive studies of ion beam Ions: bunch length

Main challenges for 2016 MDs: – High intensity beams (limitations, losses, lifetime…) – 800 MHz RF system (phase and voltage control) – Monitoring of scrubbing, space charge and optics – Synchrotron frequency shift at various energies Simulations: – multi-bunch beam (72 bunches?) + phase-loop SPS impedance – Refinement of the model (1 Ohm inductance?) => search for new contributors – Follow-up of the impedance reduction (prototyping) – HOMs damping: design of the improved HOM couplers (factor 3-4) – end 2016 Studies for ions (2015 data analysis and new p-Pb LHC run): – Space charge, IBS and WP optimization – Slip stacking: simulations with realistic machine parameters, 800 MHz, bunch rotation A. Lasheen

Main challenges for 2016 MDs: – High intensity beams (limitations, losses, lifetime…) – 800 MHz RF system (phase and voltage control) – Monitoring of scrubbing, space charge and optics – Synchrotron frequency shift at various energies Simulations: – multi-bunch beam (72 bunches?) + phase-loop SPS impedance – Refinement of the model (1 Ohm inductance?) => search for new contributors – Follow-up of the impedance reduction (prototyping) – HOMs damping: design of the improved HOM couplers (factor 3-4) – end 2016 Studies for ions (2015 data analysis and new p-Pb LHC run): – Space charge, IBS and WP optimization – Slip stacking: simulations with realistic machine parameters, 800 MHz, bunch rotation A. Lasheen

Merry Christmas! Happy New Year!