review of FCC-hh optics & beam dynamics IPNO, Orsay, Paris November 2015 Reviewers: S. Fartoukh (CERN), O. Napoly (CEA), E. Todesco (CERN), F. Zimmermann (CERN, chair ) Work supported by the European Commission under the HORIZON 2020 project EuroCirCol, grant agreement

review agenda Time (19.11)lengthtitlespeaker 14:00Welcome and review goalsMichael Benedikt 14:00-14:2020 min.Arc lattice, lattice integrationAntoine Chance 14:20-14:4020 min.IR latticeAndrei Seryi 14:40-14:5010 min.Minimum separation of detectorsRob Appleby 14:50-15:0515 min.Collimation system requirementsStefano Redaelli 15:05-15:2015 min.Betatron& momentum coll. latticesAntoine Lachaize 15:20-15:4020 min.Collimation tracking & evaluationJames Molson 15:40-16:1030 min.Discussion 16:10-16:3020 min.Coffee break 16:30-16:4515 min.Injection lattice sectionFlorian Burkart 16:45-16:5510 min.Integration of RFBernhard Holzer 16:55-17:1015 min.Extraction/dump lattice sectionFlorian Burkart 17:10-17:3020 min.Errors,tolerances,corrections DABarbara Dalena 17:30-18:0030 min.Overall layout & optimizationDaniel Schulte 18:00-18:3030 min.Discussion Time (20.11)lengthtitleSpeaker 09:00-11:00120 min.Executive session (closed)reviewers Additional invitees: WP2 and WP3 participants, R. Aleksan (ECB chair)

1.review the design status and performance of all dedicated insertions 2.review the overall lattice integration and space allocation/optimization 3.review the performance of the integrated lattice in terms of dynamic aperture, error tolerances etc. 4.identify any areas with optimization potential and propose high-priority actions towards the next milestone, FCC week Rome in April review goals

general remarks enormous progress after only half a year of EuroCirCol project ultimate optics parameters appear within reach tools and algorithms ready (IR debris, collimation efficiency, magnet errors,…) now it is time to focus on the design details

arc lattice, DS, integration comments: choice of magnet aperture is a good starting point, but looks tight recommendations: study implications of aperture on minimum injection energy further optimization of the filling factor (cell length [aperture!], phase advance per cell [60 o instead of 90 o ?], length of insertions, …) make a second iteration on interconnection length examine necessity of TSS’s and, if necessary, optimize their location to avoid constraints on phase advance add (and evaluate the need for) lattice and spool piece correctors, define number of families and correction algorithms

IR design comments: not all parameters were presented recommendations: look at chromatic properties with low-  optics, assess the need for correction, and develop solution together with MDI team determine target value for l*; eventually reassess magnitude of the crossing angle assess optics flexibility at low  *; why is the optics no longer antisymmetric from Q4? demonstrate injection optics with  *~10 m (peak-  < 1 km in the triplet) continue effort to reduce peak radiation dose

collimation comments: simulation tools are on good track length of collimation insertions scales quadratically with gap size recommendations: assess length of the secondary collimator jaws confirm and possibly revise gap size with help of shower simulations attempt to introduce dispersion between primary and secondary collimators

injection lattice comments: several 100 beam transfers to fill the FCC recommendations: insertions like these should be kept flexible enough to be used as phase trombone station

RF integration comments: the dogleg may need substantial space (several 100 m) recommendations: develop a baseline optics and layout for the RF system

extraction lattice comments: this is a challenging system recommendations and questions: does the present optics solution fulfil the basic constraints for an extraction insertion? E.g.  /2 phase advance between MKD and TCDQ large  function (>5 km) at the dump

errors, alignment, DA comments: tools are on good track a lot of experience from HL-LHC recommendations: study effect of random errors and specify maximum tolerable systematics at injection develop correction schemes and mitigation measures (e.g. x/y phase advance split) 2 nd iteration on magnet table together with magnet experts

overall layout & optimization comments: on good track for the arcs and the two main experimental IRs more work and details needed for other IRs recommendations: continue the excellent work