The HiLumi LHC Design Study (a sub-system of HL-LHC) is co-funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement Fermi Research Alliance, LLC operates Fermilab under Contract DE-AC02-07CH11359 with the US Department of Energy. This work was partially supported by the US LHC Accelerator Research Program (LARP). Weak-strong beam-beam simulations for HL-LHC A.Valishev (Fermilab/US LARP) and T.Pieloni (CERN) for WP2 Task th HiLumi WP2 TL Meeting July 8, 2013 Acknowledgments: D.Banfi, J.Barranco, S.Fartoukh, B.Muratori, K.Ohmi, D.Shatilov, S.White, F.Zimmermann

HL-LHC Beam-Beam Study Evaluate beam-beam for HL-LHC scenarios, identify minimum requirements –  *, crossing scheme, compensation Evaluate limitations Evaluate limitations Luminosity leveling techniques Luminosity leveling techniques Develop self-consistent simulations of beam-beam with other dynamical effects Develop self-consistent simulations of beam-beam with other dynamical effects But mostly rely on weak-strong simulations as a well- tested approach But mostly rely on weak-strong simulations as a well- tested approach Support new ideas Support new ideas 8 Jul A.Valishev, Weak-strong simulations2

8 Jul A.Valishev, Weak-strong simulations3 Strategy Use a variety of methods and move from the least time- consuming simulations to more elaborate multiparticle tracking Use a variety of methods and move from the least time- consuming simulations to more elaborate multiparticle tracking FMA – Tune footprint and resonances (very fast) FMA – Tune footprint and resonances (very fast) Dynamic Aperture (fast) Dynamic Aperture (fast) Full-scale multi-particle simulation of intensity and emittance life time (slow) Full-scale multi-particle simulation of intensity and emittance life time (slow) Simplify the simulated system where possible Simplify the simulated system where possible e.g. no long-range for studies of certain aspects of head-on e.g. no long-range for studies of certain aspects of head-on Task members use different codes and tools Task members use different codes and tools Converge on a number of common cases for benchmarking Converge on a number of common cases for benchmarking

8 Jul A.Valishev, Weak-strong simulations4 People and Tools T.Pieloni, D.Banfi, J.Baranco, B.Muratori – SixTrack T.Pieloni, D.Banfi, J.Baranco, B.Muratori – SixTrack D.Shatilov, A.Valishev – Lifetrac D.Shatilov, A.Valishev – Lifetrac K.Ohmi K.Ohmi

Recent Sixtrack development (1/2) Run environment at Run environment at Huge resources – more than 500k jobs Huge resources – more than 500k jobs New post-processing (x200 in performance) New post-processing (x200 in performance) New file infrastructure New file infrastructure Crab Cavity Crab Cavity Strong bunch tilting implemented Strong bunch tilting implemented Frequency Map Analysis Frequency Map Analysis Sussix analysis of Sixtrack tracking data Sussix analysis of Sixtrack tracking data 8 Jul A.Valishev, Weak-strong simulations5

Recent Sixtrack development (2/2) Verification of 6D beam-beam implementation (ongoing) Verification of 6D beam-beam implementation (ongoing) Code logic checked Code logic checked Actual implementation is tested with simulations Actual implementation is tested with simulations Tune shift vs. x-angle Tune shift vs. x-angle Synchrotron side bands Synchrotron side bands 8 Jul A.Valishev, Weak-strong simulations6

Selected Sixtrack results (1/6) 8 Jul A.Valishev, Weak-strong simulations7 Possibility to have with Sixtrack Frequency map analysis Short run modified and ready for release

Selected Sixtrack results (2/6) 8 Jul A.Valishev, Weak-strong simulations8 The 6D BB lens seems working correctly, no problems found. Weighted slices location Synchrotron side bands

Selected Sixtrack results (3/6) 8 Jul A.Valishev, Weak-strong simulations9 Tune shifts versus crossing angle

Selected Sixtrack results (4/6) 8 Jul A.Valishev, Weak-strong simulations10 Preliminary Different types of optics without multipole errors

Selected Sixtrack results (5/6) 8 Jul A.Valishev, Weak-strong simulations11  *=10 cm with multipole errors Preliminary

Selected Sixtrack results (6/6) 8 Jul A.Valishev, Weak-strong simulations12 Tune  *=10 cm with/without multipole errors Preliminary

Sixtrack next steps Verify DA without beam-beam to agree with Task 2.3 results Verify DA without beam-beam to agree with Task 2.3 results Beam-beam + multipole errors Beam-beam + multipole errors Beam-beam + Crab Cavities Beam-beam + Crab Cavities Beam-beam + Crab Cavities + multipoles Beam-beam + Crab Cavities + multipoles Beam-beam + noise Beam-beam + noise … 8 Jul A.Valishev, Weak-strong simulations13

Recent Lifetrac development Element-by-element tracking fully implemented Element-by-element tracking fully implemented Drift-kick with thin multipole, dipole edge, solenoid, orbit corr. Drift-kick with thin multipole, dipole edge, solenoid, orbit corr. Streamlined mad-x mask file -> Lifetrac input file conversion Streamlined mad-x mask file -> Lifetrac input file conversion Implemented closed orbit calculation Implemented closed orbit calculation Checked the agreement of DA without beam- beam with Task 2.3 results on a test case from Massimo Checked the agreement of DA without beam- beam with Task 2.3 results on a test case from Massimo 8 Jul A.Valishev, Weak-strong simulations14

8 Jul A.Valishev, Weak-strong simulations15 Selected Lifetrac results (1/) S.White, A.Valishev HL-LHC lattice without magnetic errors (only chroma sextupoles) DA based on 10 6 tracking turns. N p =2×10 11,  =2.5  m

8 Jul A.Valishev, Weak-strong simulations16 Selected Lifetrac results (2/) D.Banfi, A.Valishev HL-LHC lattice without magnetic errors (only chroma sextupoles) DA based on 10 6 tracking turns.  *=0.15m,  =590  rad,  =2.5  m

8 Jul A.Valishev, Weak-strong simulations17 Selected Lifetrac results (3/)  *=15cm  =590  rad  p/p=0  z =7.5cm  *=33cm  =590  rad  p/p=0  z =4cm D.Shatilov, A.Valishev Linear HL-LHC lattice (no sextupoles) + beam-beam (head-on & long-range) DA based on 10 6 tracking turns, FMA – 2 13 turns

8 Jul A.Valishev, Weak-strong simulations18 Selected Lifetrac results (4/) HL-LHC lattice without magnetic errors (only chroma sextupoles) DA based on 10 6 tracking turns.  *=0.15m,  =590  rad,  =2.5  m DA is ok with BB tune shift of  = at A/  = 12.5 with full crab on, no multipole errors

8 Jul A.Valishev, Weak-strong simulations19 Selected Lifetrac results (5/) Multi-particle simulation  N >500 hr,   =18 hr,  L =150 hr

8 Jul A.Valishev, Weak-strong simulations20 Selected Lifetrac results (6/) Some margin at beginning of fill – can reduce x-angle? Some margin at beginning of fill – can reduce x-angle? 15% margin at end of fill with  =480  rad should allow some emittance growth 15% margin at end of fill with  =480  rad should allow some emittance growth What happens at intermediate steps? What happens at intermediate steps?

Lifetrack next steps Beam-beam + multipole errors Beam-beam + multipole errors Beam-beam + Crab Cavities Beam-beam + Crab Cavities Beam-beam + Crab Cavities + multipoles Beam-beam + Crab Cavities + multipoles Beam-beam + noise Beam-beam + noise … 8 Jul A.Valishev, Weak-strong simulations21

Effects of Noise K. Ohmi 8 Jul A.Valishev, Weak-strong simulations22

8 Jul A.Valishev, Weak-strong simulations23 Summary Both Sixtrack and Lifetrac seem to be ready for physics production Both Sixtrack and Lifetrac seem to be ready for physics production Good agreement between two codes Good agreement between two codes Several cases studied with beam-beam only and simulations with multipoles have begun Several cases studied with beam-beam only and simulations with multipoles have begun 6D kick in Sixtrack checked 6D kick in Sixtrack checked ‘New’ scenario challenging in terms of bb ‘New’ scenario challenging in terms of bb Preliminary results encouraging – DA at  =0.033 is ok but some emittance growth is observed (mitigate by tune adjustment?) Preliminary results encouraging – DA at  =0.033 is ok but some emittance growth is observed (mitigate by tune adjustment?) We should be able to address the ‘New 2 ’ scenario fairly quickly We should be able to address the ‘New 2 ’ scenario fairly quickly The missing piece is wire compensation The missing piece is wire compensation