January 26 th 2015 European Organization for Nuclear Research CLIC WORKSHOP 26/01/2015 CLIC WORKSHOP 2015, Geneva, Switzerland Optics Design and Beam Dynamics Modelling Fabien Plassard, Rogelio Tomas Garcia, Andrea Latina, Hector Garcia Morales 1,3 Université Paris Sud, France Royal Holloway University of London, UK CERN, Switzerland ,3

slide 2/12 OUTLINE 1 1 Conclusions A A B B C C A A B B Current Final Focus System design Final doublet QF1 and QD0 integration Organisation Européenne pour la Recherche Nucléaire Performance optimization forseen for CLIC & ILC Final Focus C C European Organization for Nuclear Research CLIC WORKSHOP 26/01/2015

Current Final Focus System design Organisation Européenne pour la Recherche Nucléaire Conclusions Organisation Européenne pour la Recherche Nucléaire  CLIC and ILC Final Focus systems are based on the local compensation scheme proposed by P. Raimondi and A. Seryi allowing chromatic aberration corrections at the Final Doublet QD0 & QF1 and short FFS Local scheme  Challenging requirements on the final quadrupole QD0 alignment and stabilization slide 3/12 European Organization for Nuclear Research CLIC WORKSHOP 26/01/2015

slide 3/14 Final Doublet QF1 and QD0 integration Organisation Européenne pour la Recherche Nucléaire Conclusions Organisation Européenne pour la Recherche NucléaireEuropean Organization for Nuclear Research CLIC WORKSHOP 26/01/2015  QD0 needs an active magnetic shielding to avoid undesired interactions with magnetic field generated by the main solenoid of the detector  The challenge of the anti-solenoid design is the geometry and field optimization for the field compensation and forces involved (main solenoid, anti-solenoid and QD0) and thus avoid instabilty issues and luminosity loss  Stabilization of QD0 to 0.15 nm for frequencies above 4Hz is the most challenging specification in the BDS  Pre-insulator (green block) using active isolation can mitigate vibrations of QD0 inside the detector but still need to prove it in a detector-like environment  Remove QD0 from the detector on the stable ground of the tunnel allows to avoid this challenge Organisation Européenne pour la Recherche Nucléaire slide 4/12 European Organization for Nuclear Research CLIC WORKSHOP 26/01/2015 Conclusions

slide 3/14 Organisation Européenne pour la Recherche Nucléaire Conclusions Organisation Européenne pour la Recherche NucléaireEuropean Organization for Nuclear Research CLIC WORKSHOP 26/01/2015  Easy for anti-solenoid correction no interaction between QD0 field and main solenoid field  Same optics for both detectors and QD0 Hybrid Magnet (difficult to install in the detector), more stable than SC magnet (vibration <1nm)  Fewer engineering constraints and larger detector acceptance  Increase the tuning difficulty  Challenging FFS design optimization needed to achieve the required performances Organisation Européenne pour la Recherche Nucléaire slide 5/12 European Organization for Nuclear Research CLIC WORKSHOP 26/01/2015 Conclusions

slide 3/14 Organisation Européenne pour la Recherche Nucléaire Conclusions Organisation Européenne pour la Recherche NucléaireEuropean Organization for Nuclear Research CLIC WORKSHOP 26/01/2015 Organisation Européenne pour la Recherche Nucléaire slide 6/12 European Organization for Nuclear Research CLIC WORKSHOP 26/01/ Conclusions ParameterUnitCLIC 500 GeVCLIC 3 TeVILC 500 GeVILC 1 TeV Beam energyGeV Bunches per train Bunch population Repetition rateHz Hor. Norm. emittanceμmμm Vert. Norm. emittancenm Hor. Beta at IPmm 8811 Vert. Beta at IPmm Hor. beam size at IPnm Ver. Beam size at IPnm Bunch lengthμmμm Energy spread (rms)% Luminosity CLIC & ILC parameters

slide 3/14 Organisation Européenne pour la Recherche Nucléaire Conclusions Organisation Européenne pour la Recherche NucléaireEuropean Organization for Nuclear Research CLIC WORKSHOP 26/01/2015 Organisation Européenne pour la Recherche Nucléaire slide 6/12 European Organization for Nuclear Research CLIC WORKSHOP 26/01/ Conclusions

slide 3/14 Organisation Européenne pour la Recherche Nucléaire Conclusions Organisation Européenne pour la Recherche NucléaireEuropean Organization for Nuclear Research CLIC WORKSHOP 26/01/ (BBA + Knobs) Organisation Européenne pour la Recherche Nucléaire slide 6/12 European Organization for Nuclear Research CLIC WORKSHOP 26/01/ Conclusions

slide 3/14 Organisation Européenne pour la Recherche Nucléaire Conclusions Organisation Européenne pour la Recherche NucléaireEuropean Organization for Nuclear Research CLIC WORKSHOP 26/01/2015 Preliminary results Comes from T.Okugi presentation, AWLC14 “large L* option” slide 3/14 Organisation Européenne pour la Recherche Nucléaire European Organization for Nuclear Research CLIC WORKSHOP 26/01/2015 Organisation Européenne pour la Recherche Nucléaire slide 7/12 European Organization for Nuclear Research CLIC WORKSHOP 26/01/ Conclusions

slide 3/14 Organisation Européenne pour la Recherche Nucléaire Conclusions Organisation Européenne pour la Recherche NucléaireEuropean Organization for Nuclear Research CLIC WORKSHOP 26/01/2015 CCS optimization  Comparative studies between traditional and local scheme (H. Garcia Morales) show that traditional design is easier to tune but chromaticity is not locally corrected Original design New design (extra sextupoles)  FFS lattice has been optimized by doubling the number of sextupoles in CCS allowing to increase chromatic aberrations cancellation before the Final Doublet and thus increasing performances slide 3/14 Organisation Européenne pour la Recherche Nucléaire European Organization for Nuclear Research CLIC WORKSHOP 26/01/2015 Organisation Européenne pour la Recherche Nucléaire slide 8/12 European Organization for Nuclear Research CLIC WORKSHOP 26/01/ Conclusions

slide 3/14 Organisation Européenne pour la Recherche Nucléaire Conclusions Organisation Européenne pour la Recherche NucléaireEuropean Organization for Nuclear Research CLIC WORKSHOP 26/01/  FFS performances were significantly improved with the optimized design (with extra sextupoles) slide 3/14 Organisation Européenne pour la Recherche Nucléaire European Organization for Nuclear Research CLIC WORKSHOP 26/01/2015 Organisation Européenne pour la Recherche Nucléaire slide 9/12 European Organization for Nuclear Research CLIC WORKSHOP 26/01/ Conclusions

slide 3/14 Organisation Européenne pour la Recherche Nucléaire Conclusions Organisation Européenne pour la Recherche NucléaireEuropean Organization for Nuclear Research CLIC WORKSHOP 26/01/2015  The large number of sextupoles present in the lattice (16) makes the tuning process more difficult and longer  Beam Based Alignment & sextupole knobs algorithms  Results for the 1st run for optimal and non-optimal weights factors More iterations are needed slide 3/14 Organisation Européenne pour la Recherche Nucléaire European Organization for Nuclear Research CLIC WORKSHOP 26/01/2015 Organisation Européenne pour la Recherche Nucléaire slide 10/12 European Organization for Nuclear Research CLIC WORKSHOP 26/01/ Conclusions

slide 3/14 Performance optimization forseen for ILC & CLIC FFS Organisation Européenne pour la Recherche Nucléaire Conclusions Organisation Européenne pour la Recherche NucléaireEuropean Organization for Nuclear Research CLIC WORKSHOP 26/01/2015  Dispersion optimization can improve chromatic effect corrections and reduces sextupole strenghts. Need to find optimal bending magnet strenght to maximize higher order aberration corrections and minimize synchrotron radiation while keeping the machine in the boundaries of the tunnel  Optimization of the optic configuration or introduction of new optics (sextupoles, octupoles...?)  Tuning simulations: Check alignement performance with more realistic tuning set up (for ILC) Applying Simplex+BBA+Knobs procedure for the different lattices slide 3/14 Organisation Européenne pour la Recherche Nucléaire European Organization for Nuclear Research CLIC WORKSHOP 26/01/2015 Organisation Européenne pour la Recherche Nucléaire slide 11/12 European Organization for Nuclear Research CLIC WORKSHOP 26/01/ Conclusions

slide 3/14 CONCLUSIONS Organisation Européenne pour la Recherche Nucléaire Conclusions Organisation Européenne pour la Recherche NucléaireEuropean Organization for Nuclear Research CLIC WORKSHOP 26/01/2015 slide 3/14 Organisation Européenne pour la Recherche Nucléaire European Organization for Nuclear Research CLIC WORKSHOP 26/01/2015 Organisation Européenne pour la Recherche Nucléaire slide 12/12 European Organization for Nuclear Research CLIC WORKSHOP 26/01/ Conclusions Comparative studies should continue between Local & Traditional design performances (Luminosity and Tuning)