Future Accelerators

XLV International Meeting on Fundamental Physics Granada, April 25th. 2017

Sergio Bertolucci University of Bologna and INFN After LHC initial phase :

 We have consolidated the (a wealth of measurements at 7-8 TeV, including the

rare, and very sensitive to New Physics, Bs  μμ decay)

 We have completed the Standard Model: discovery of the messenger of the BEH-field, the discovery

 We have NO evidence of New Physics, although hints are coming (and going)

0 CMS and LHCb B s,d →μμ combination

Fit to full run I data sets of both experiments, sharing parameters

Result demonstrates power of combing data from >1 experiment (an LHC first!)

projection of invariant mass in most sensitive bins

Sept 2014 LHCb 5news Where we stand

 We have exhausted the number of “known unknowns” within the current paradigm.

 Although the SM enjoys an enviable state of health, we know it is incomplete, because it cannot explain several outstanding questions, supported in most cases by experimental observations. Main outstanding questions in today’s particle physics

Higgs boson and EWSB :  mH natural or fine-tuned ?  ν masses and and their origin  if natural: what new physics/symmetry?  what is the role of H(125) ?  does it regularize the divergent VLVL cross-section  Majorana or Dirac ? at high M(VLVL) ? Or is there a new dynamics ?  CP violation  elementary or composite Higgs ?  additional species  sterile ν ?  is it alone or are there other Higgs bosons ?  origin of couplings to fermions Dark :  coupling to ?  composition: WIMP, sterile neutrinos,  does it violate CP ? axions, other hidden sector particles, ..  cosmological EW phase transition  one type or more ? (is it responsible for baryogenesis ?)  only gravitational or other interactions ?

The two epochs of Universe’s accelerated expansion: Quarks and :  primordial: is inflation correct ?  why 3 families ? which (scalar) fields? role of quantum gravity?  masses and mixing  today: dark energy (why is Λ so small?) or  CP violation in the sector gravity modification ?  matter and asymmetry  baryon and charged lepton number violation Physics at the highest E-scales:  how is gravity connected with the other forces ? At what E scale(s)  do forces unify at high energy ? are the answers ? F. Gianotti, LHCP 2014, 6/6/2014 7 Looking for “unknown unknowns” Needs a synergic use of:

 High-Energy experiments (solar, short/long baseline, reactors, 0ββ decays),  cosmic surveys (CMB, Supernovae, BAO, Dark E)  gravitational waves  dark matter direct and indirect detection  precision measurements of rare decays and phenomena  dedicated searches (WIMPS, axions, dark-sector particles)  ….. From the Update of the European Strategy for Particle Physics

The success of the LHC is proof of the effectiveness of the European organizational model for particle physics, founded on the sustained long-term commitment of the CERN Member States and of the national institutes, laboratories and universities closely collaborating with CERN. Europe should preserve this model in order to keep its leading role, sustaining the success of particle physics and the benefits it brings to the wider society.

The scale of the facilities required by particle physics is resulting in the globalization of the field. The European Strategy takes into account the worldwide particle physics landscape and developments in related fields and should continue to do so. From the P5 report

Particle physics is global. The United States and major players in other regions can together address the full breadth of the field’s most urgent scientific questions if each hosts a unique world-class facility at home and partners in high- priority facilities hosted elsewhere. Strong foundations of international cooperation exist, with the Large (LHC) at CERN serving as an example of a successful large international science project. Reliable partnerships are essential for the success of international projects. Building further international cooperation is an important theme of this report, and this perspective is finding worldwide resonance in an intensely competitive field. From Japan HEP Community

The committee makes the following recommendations concerning large-scale projects, which comprise the core of future high energy physics research in Japan.

Should a new particle such as a Higgs boson with a mass below approximately 1 TeV be confirmed at LHC, Japan should take the leadership role in an early realization of an e+e- linear collider. In particular, if the particle is light, experiments at low collision energy should be started at the earliest possible time. In parallel, continuous studies on new physics should be pursued for both LHC and the upgraded LHC version. Should the energy scale of new particles/physics be higher, accelerator R&D should be strengthened in order to realize the necessary collision energy.

Should the neutrino mixing angle θ13 be confirmed as large, Japan should aim to realize a large-scale neutrino detector through international cooperation, accompanied by the necessary reinforcement of accelerator intensity, so allowing studies on CP symmetry through neutrino oscillations. This new large-scale neutrino detector should have sufficient sensitivity to allow the search for proton decays, which would be direct evidence of Grand Unified Theories. The LHC timeline

7-8 TeV 13-14 TeV HL-LHC Run 1 Run 2 Run 3 ~3000 fb-1

Splices Injectors New fixed upgrade low-β* quads

~300 fb-1 ~100 fb-1 Where is New Physics?

The question

 Is the mass scale beyond the LHC reach ?  Is the mass scale within LHC’s reach, but final states are elusive ?

We should be prepared to exploit both scenarios, through:

 Precision  Sensitivity (to elusive signatures)  Extended energy/mass reach Extending the reach…

 Weak boson scattering  Higgs properties  Supersymmetry searches and measurements  Exotics  t properties  Rare decays  CPV  ..etc 13 TeV vs 8 TeV Run2 @13 Tev in 2016

• Exceptional performances of LHC • Experiments in good shape, keeping up with the increased machine performances The HL-LHC Project

• New IR-quads Nb3Sn (inner triplets)

• New 11 T Nb3Sn (short) dipoles • Collimation upgrade • Cryogenics upgrade • Crab Cavities • Cold powering • Machine protection • … Major intervention on more than 1.2 km of the LHC Project leadership: L. Rossi and O. Brüning Higgs couplings fit at HL-LHC

CMS

CMS Projection

Assumption NO invisible/undetectable contribution to GH: - Scenario 1: system./Theory err. unchanged w.r.t. current analysis - Scenario 2: systematics scaled by 1/sqrt(L), theory errors scaled by ½  gg loop at 2-5% level  down-type fermion couplings at 2-10% level  direct top coupling at 4-8% level  gg loop at 3-8% level Coupling Ratios Fit at HL-LHC

 Fit to coupling ratios:

 No assumption BSM contributions to GH  Some theory systematics cancels in the ratios  Loop-induced Couplings gg and gg treated as independent parameter

 kg/kZ tested at 2%  gg loop (BSM) kt/kg at 7-12% nd  2 generation ferm. km/kZ at 8% ATLAS

DG/G = 2 Dk/k Extending the reach…. Luminosity Levelling, a key to success

 High peak luminosity  Minimize pile-up in experiments and provide “constant” luminosity

• Obtain about 3 - 4 fb-1/day (40% stable beams) • About 250 to 300 fb-1/year Baseline parameters of HL for reaching 250 -300 fb-1/year

25 ns 50 ns 25 ns is the option # Bunches 2808 1404 However: p/bunch [1011] 2.0 (1.01 A) 3.3 (0.83 A)

50 ns should be kept as alive and eL [eV.s] 2.5 2.5 possible because we DO NOT have s [cm] 7.5 7.5 enough experience on the actual z s [10-3] 0.1 0.1 limit (e-clouds, Ibeam) dp/p

gex,y [mm] 2.5 3.0 b* [cm] (baseline) 15 15 X-angle [mrad] 590 (12.5 s) 590 (11.4 s) Loss factor 0.30 0.33 Continuous global Peak lumi [1034] 6.0 7.4 optimisation with LIU Virtual lumi [1034] 20.0 22.7

Tleveling [h] @ 5E34 7.8 6.8 #Pile up @5E34 123 247

Courtesy Oliver Brüning The detectors challenge

7 – 11 orders of magnitude between inelastic and “interesting” - “discovery” physics event rate The detectors challenge In order to exploit the LHC potential, experiments have to maintain full sensitivity for discovery, while keeping their capabilities to perform precision measurements at low pT, in the presence of:  Pileup  ≈ 50 events per crossing by LS2  ≈ 60 events per crossing by LS3  ≈ 140 events per crossing by HL-LHC  Radiation damage  Requires work to maintain calibration  Limits performance-lifetime of the detectors • Light loss (calorimeters) • Increased leakage current (silicon detectors) Higher √s in the LHC tunnel ?

Fabiola Gianotti, FCC Week 2016

16 TeV vs 14 TeV 28 TeV vs 14 TeV

WG set up to explore technical feasibility of pushing LHC energy to: 1) design value: 14 TeV Various options, 2) ultimate value: 15 TeV (corresponding to max dipole field of 9 T) with increasing 3) beyond (e.g. by replacing 1/3 of dipoles with 11 T Nb3Sn magnets) amount of HW  Identify open risks, needed tests and technical developments, trade-off changes, technical between energy and machine efficiency/availability challenges, cost,  Report on 1) end 2016, 2) end 2017, 3) end 2018 (in time for ES) and physics reach HE-LHC (part of FCC study): ~16 T magnets in LHC tunnel ( √s~ 30 TeV)  uses existing tunnel and infrastructure; can be built at fixed budget  strong physics case if new physics from LHC/HL-LHC  powerful demonstration of the FCC-hh magnet technology A lepton collider: a decisive asset…

..if  Can be decided/built soon  It might start at 250 Gev, but it should be upgradable at 500 GeV, with a possible extension to 1 TeV c.m. Best candidate: the International Linear Collider:  Mature design  TDR delivered  Japanese community has submitted to the government a request to host it.

ILC: not only a precision machine

 Great impact in exploring the EWK part of Supersimmetry, in a region which might be not accessible at the LHC, because the unfavorable S/B.  A fundamental contribution in the precision studies of the W and Z bosons and the .

The joint information coming from LHC and ILC might be a “conditio sine qua non” to enable the next at the energy frontier International Linear Collider (ILC) Technical Design Report released Total length: 31 km in June 2013

√s=250 (initial), 500 (design), 1000 (upgrade) GeV L ~ 0.75-5 x 1034 (running at √s=90, 160, 350 GeV also envisaged)

Main challenges:  ~ 15000 SCRF cavities (1700 cryomodules), 31.5 MV/m gradient  1 TeV machine requires extension of main Linacs (50 km) and 45 MV/m  Positron source; suppression of electron-cloud in positron damping ring  Final focus: squeeze and collide nm-size beams

 Japan interested to host  decision ~2018 based also on ongoing international discussions Mature technology: 20 years of R&D experience worldwide (e.g. European xFEL at DESY is 5% of ILC, gradient 24 MV/m, some cavities achieved 29.6 MV/m)  Construction could technically start ~2019, duration ~10 years  physics could start ~2030

LHeC, not only PDFs

Continuing activity on Physics 34 -2 -1 Detector Goal: L~10 cm s ERL Five Major Themes of LHeC PHysics

The Cleanest High Resolution Microscope of the World

The Electron Beam Upgrade of the LHC

The First High Precision Higgs Facility

Discovery Beyond the Standard Model

A Unique Nuclear Physics Facility The LHeC PDF Programme

Resolve parton structure of the proton completely: uv,dv,sv?,u,d,s,c,b,t and xg Unprecedented range, sub% precision, free of parameterisation assumptions, Resolve p structure, solve non linear and saturation issues, test QCD, N3LO…

Strong Coupling in inclusive DIS at LHeC to 0.1%

Lattice?? Jets?? BCDMS?? GUTs? Higgs in pp

Note that LHC is about to reach its own limits on PDFs. pp is NOT DIS, cf ATLAS W,Z to 0.5% Top electric charge Top Physics EDM and MDM Pair production Single production Anomalous t-q-y and t-g-Z

Vtb

Top spin

W-t-b FCNC top Higgs CC interaction Top PDF

Top mass

Top-Higgs (1602.04670)

CP nature of ttH (1702.03426)

Just started to fully see the huge potential of top physics in ep at high energies High Precision for the LHC

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Spacelike MW to 10 MeV from ep Predict the Higg cross section in pp to  Electroweak thy test at 0.01% ! 0.2% precision which matches the M H  measurement and removes the PDF error Predict MW in pp to 2.8 MeV Remove PDF uncertainty on MW LHC Search Range Extension - worth the Lumi Upgrade External, reliable input (PDFs, factorisation..) is crucial for range extension + CI interpretation

GLUON QUARKS SUSY, RPC, RPV, LQS.. Exotic+ Extra boson searches at high mass Higgs Physics with ep

κ in % HL LHC LHeC HL LHeC HE FCC-eh H  bb 10 0.5 0.3 0.2 H  cc 50? 4 2.8 1.8

• Higgs is produced via an EW process in ep collisions – No contamination from ggF and no pile-up – Precise theoretical control of the cross-section • Superior sensitivity of ep with respect to pp in various aspects: – h  bb,cc,tautau couplings, unique access to WW-H-WW • Access to h  gg? – Structure of hVV and top Yukawa couplings • Access to hh and invisible decays (dark matter) in ep collisions • Removal of QCD uncertainties to gg  H calculation for LHC • LHC can be transformed into a high precision Higgs facility. Possible Discoveries Beyond SM with LHeC QCD:

Search for Sterile Neutrinos (LHC LHeC) No saturation

BFKL

Instantons

Higher symmetry embedding QCD

Electroweak:

EFTs

Exotic Higgs Decays

Extension of Higgs Sector It is a wasted p that does NOT collide with an e beam (Oliver Fischer - 2017) Sterile Neutrinos … It would be a waste not to exploit the 7 TeV beams for ep and eA physics at some stage during the LHC time (Guido Altarelli – 2008) Electron-Ion Nuclear and Particle Physics

Extension of kinematic range in lA by 4 orders of magnitude: will change QCD view on nuclear structure and parton dynamics

May lead to genuine surprises…

- No saturation of xg (x,Q2) ? - Small fraction of diffraction ? - Broken isospin invariance ? - Flavour dependent shadowing ?

Relates to LHC Heavy Ion Physics - Quark Gluon Plasma - Collectivity of small nuclei (p)? - ..

Saturation: needs large xg at small x ep and eA LHeC ERL Baseline Design

Concurrent operation to pp, LHC becomes a 3 beam faclity. P < 100 MW. CW Luminosity for LHeC, HE-LHeC and FCC Location + Footprint of the electron ERL LHC FCC

A 9km ERL is a small add-on for the FCC Energy – Cost – Physics – Footprint Doubling the energy to 120 GeV hugely are being reinvestigated Increases cost and effort. Powerful ERL for Experiments (ep.yp): PERLE at Orsay PERLE at Orsay: New Collaboration: BINP,title CERN, Daresbury/Liverpool, Jlab, Orsay + CDR publication imminent. 3 turns, 2 Linacs, 15mA, 802 MHz ERL facility -Demonstrator of LHeC -Technology (SCRF) Development Facility -Low E electron and photon beam physics -High intensity: 100 x ELI

See https://indico.lal.in2p3.fr/event/3428/ More Linear Colliders...

Future Circular Collider Study Goal: CDR for European Strategy Update 2018/19 International FCC collaboration (CERN as host lab) to study: • pp-collider (FCC-hh)  main emphasis, defining infrastructure requirements ~16 T  100 TeV pp in 100 km

• 80-100 km tunnel infrastructure in Geneva area, site specific • e+e- collider (FCC-ee), as potential first step • p-e (FCC-he) option, integration one IP, FCC-hh & ERL • HE-LHC with FCC-hh technology

Future Circular Collider Study Michael Benedikt 62 3rd MT Meeting, GSI Darmstadt, 31. Jan. 2017 FCC: physics reach in a nutshell

FCC-hh: 100 TeV  explore directly the 10-50 TeV E-scale  provide conclusive exploration of EWSB dynamics  study nature the Higgs potential and EW phase transition  say final word about heavy WIMP dark matter  etc.

FCC-ee: 90-350 GeV  indirect sensitivity to E scales up to O(100 TeV) by measuring most Higgs couplings to O(0.1%), improving the precision of EW parameters measurements by ~20-200,

ΔMW < 1 MeV, Δmtop ~ 10 MeV, etc.  sensitivity to very-weakly coupled physics (e.g. light, weakly-coupled dark matter)  etc.

FCC-ep: ~ 3.5 TeV

 unprecedented measurements of PDF and αs  new physics: leptoquarks, eeqq contact interactions, etc.  Higgs couplings (e.g. Hbb to ~ 1%)  etc.

Machines are complementary and synergetic, e.g. from measurement of ttH/ttZ ratio, and using ttZ coupling and H branching ratio from FCC-ee, FCC-hh can measure ttH to ~ 1% The challenge is not only the machine…

Detectors R&D :

• Ultra-light, ultra-fast, ultra-granular, rad-hard, low-power Si trackers • 108 channel imaging calorimeters (power consumption and cooling at high-rate machines,..) • big-volume 5-6 T magnets (~2 x magnetic length and bore of ATLAS and CMS, ~50 GJ stored energy) to reach momentum resolutions of ~10% for p~20 TeV muons Theory:

• improved theoretical calculations (higher-order EW and QCD corrections) needed to match present and future experimental precision on EW observables, Higgs mass and branching ratios. • Work together with experiments on model-independent analyses in the framework of Effective Field Theory FCC strategic motivation

• European Strategy for Particle Physics 2013: “…to propose an ambitious post-LHC accelerator project….., CERN should undertake design studies for accelerator projects in a global context,…with emphasis on proton-proton and electron- positron high-energy frontier machines….coupled to a vigorous accelerator R&D programme, including high-field magnets and high- gradient accelerating structures,….”

• U.S. strategy and P5 recommendation 2014: ”….A very high-energy proton-proton collider is the most powerful tool for direct discovery of new particles and interactions under any scenario of physics results that can be acquired in the P5 time window….”

• International Committee on Future Acceelrators statement 2014: ”…. ICFA supports studies of energy frontier circular colliders and encourages global coordination.….”

Future Circular Collider Study Michael Benedikt 65 3rd MT Meeting, GSI Darmstadt, 31. Jan. 2017 FCC Scope: Accelerator and Infrastructure FCC-hh: 100 TeV pp collider as long-term goal  defines infrastructure needs FCC-ee: e+e- collider, potential intermediate step HE-LHC: based on FCC-hh technology Launch R&D on key enabling technologies in dedicated R&D programmes, e.g. 16 Tesla magnet program, cryogenics, SRF technologies and RF power sources

Tunnel infrastructure in Geneva area, linked to CERN accelerator complex; site-specific, as requested by European strategy

Future Circular Collider Study Michael Benedikt 66 3rd MT Meeting, GSI Darmstadt, 31. Jan. 2017 FCC Scope: Physics & Experiments

Elaborate and document - Physics opportunities - Discovery potentials

Experiment concepts for hh, ee and he Machine Detector Interface studies R&D needs for detector technologies

Overall cost model for collider scenarios including infrastructure and injectors Develop realization concepts Forge partnerships with industry

Future Circular Collider Study Michael Benedikt 67 3rd MT Meeting, GSI Darmstadt, 31. Jan. 2017 CERN Circular Colliders & FCC

1980 1985 1990 1995 2000 2005 2010 2015 2020 2025 2030 2035 2040

Constr. Physics LEP

Design Proto Construction Physics LHC – operation run 2

HL-LHC - ongoing project Design Construction Physics

~20 years

FCC – design study Design Proto Construction Physics Must advance fast now to be ready for the period 2035 – 2040 Goal of phase 1: CDR by end 2018 for next update of European Strategy

Future Circular Collider Study Michael Benedikt 68 3rd MT Meeting, GSI Darmstadt, 31. Jan. 2017 Progress on site investigations

Future Circular Collider Study Michael Benedikt 69 3rd MT Meeting, GSI Darmstadt, 31. Jan. 2017 Progress on site investigations

• 90 – 100 km fits geological situation well • LHC suitable as potential injector • The 97.75 km version, intersecting LHC, is now being studied in more detail

Future Circular Collider Study Michael Benedikt 70 3rd MT Meeting, GSI Darmstadt, 31. Jan. 2017 Common layouts for hh & ee

FCC-ee 1, FCC-ee 2, 11.9 m IP 30 mrad

FCC-ee booster (FCC-hh footprint) FCC-hh/ ee Booster 9.4 m 0.6 m Lepton beams must cross over through the common RF to enter the IP from inside. Only a half of each ring is filled with bunches.

FCC-hh Common Common layout RF (tt) RF (tt)

Max. separation of 3(4) rings is about 12 m: wider tunnel or two tunnels are necessary around the IPs, for ±1.2 km. • 2 main IPs in A, G for both machines IP • asymmetric IR optic/geometry for ee to limit to detector

Future Circular Collider Study Michael Benedikt 71 3rd MT Meeting, GSI Darmstadt, 31. Jan. 2017 parameters (pp) parameter FCC-hh HE-LHC (HL) LHC collision energy cms [TeV] 100 25 14 dipole field [T] 16 16 8.3 circumference [km] 100 27 27 # IP 2 main & 2 2 & 2 2 & 2 beam current [A] 0.5 1.27 (1.12) 0.58 bunch intensity [1011] 1 (0.2) 1 (0.2) 2.5 (2.2) 1.15 bunch spacing [ns] 25 (5) 25 (5) 25 (5) 25 * IP b x,y [m] 1.1 0.3 0.25 (0.15) 0.55 luminosity/IP [1034 cm-2s-1] 5 30 34 (5) 1 peak #events/bunch crossing 170 1020 (204) 1070 (214) (135) 27 stored energy/beam [GJ] 8.4 1.4 (0.7) 0.36 synchrotron rad. [W/m/beam] 30 4.1 (0.35) 0.18

Future Circular Collider Study Michael Benedikt 72 3rd MT Meeting, GSI Darmstadt, 31. Jan. 2017 pp/p-pbar in the L-E plane

Future Circular Collider Study Michael Benedikt 73 3rd MT Meeting, GSI Darmstadt, 31. Jan. 2017 FCC-hh MDI status

Design of interaction region • Distance from IP to first machine quadrupole L*=45 m. • Allows integrated spectrometers and compensation dipoles (or fwd solenoids) • Optics and magnet optimization for beam stay clear and collision debris.  Magnet (triplet) lifetime should be collider lifetime (from radiation damage). peak dose profile, per 3000 fb -1, vertical crossing, 15 mm thick shielding 45 L* 36 m 40 L* 45 m, spectrometer off L* 45 m, spectrometer on

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Future Circular Collider Study Michael Benedikt 74 3rd MT Meeting, GSI Darmstadt, 31. Jan. 2017 contributions: beam screen Beam power & machine(BS) & cold bore protection (BS heat radiation) Stored energy 8.4 GJ per beam Damage of a beam with an energy of 2 MJ – Factor 25 higher than for LHC, equivalent to A380 (560 t) at nominal speed (850 km/h). Can melt 12t of .

Hydrodynamic tunneling: beam penetrates ~300 m in Cu

– Collimation, control of beam losses and radiation effects (shielding) are of prime importance. – Injection, beam transfer and beam dump all critical. Machine protection issues to be addressed early on!

Future Circular Collider Study Michael Benedikt 75 3rd MT Meeting, GSI Darmstadt, 31. Jan. 2017 FCC-hh beam dilution system

Huge energy to be extracted and dumped => need large dump section 2m Beam rigidity: 167 T.km => need long way to dilute beam ~2.5km!

2.5 km dump line

1.4 km dump insertion 2.8 km collimation insertion Fluka studies: Kicker Septum 10 mrad Dilution Absorber • Bunch separation >1.8 mm bend • Branch separation: 4 cm • Keeps T<1500°C

Very reliable kickers, high segementation, new methods for triggering (laser) SC septum

Future Circular Collider Study Michael Benedikt 76 3rd MT Meeting, GSI Darmstadt, 31. Jan. 2017 5/2/2017 R&D on Superconducting Septa

Need an extraction system for safely removing the beam from the collider hybrid system: short overall length with high robustness & availability

3 candidate technologies: SuShi concept: (1) NbTi/Nb/Cu multilayer sheet SC shield creates (2) HTS tape/coating

field-free region (3) Bulk MgB2 inside strong dipole field

Future Circular Collider Study Michael Benedikt 77 3rd MT Meeting, GSI Darmstadt, 31. Jan. 2017 Synchrotron radiation beam screen prototype High synchrotron radiation load FCC-hh beam screen prototypes of proton beams @ 50 TeV: Ready for Testing 2017 in ANKA within EuroCirCol study • ~30 W/m/beam (@16 T) (LHC <0.2W/m) • 5 MW total in arcs (@1.9 K!!!) New Beam screen with ante-chamber • absorption of synchrotron radiation at 50 K to reduce cryogenic power • factor 50! reduction of cryo power

Simulation of quench behaviour Photon distribution

Future Circular Collider Study Michael Benedikt 78 3rd MT Meeting, GSI Darmstadt, 31. Jan. 2017 contributions: beam screen Cryo power for (BS)cooling & cold bore of (BSSR heat heat radiation) Overall optimisation of cryo-power, vacuum and impedance Termperature ranges: <20, 40K-60K, 100K-120K 3000 Tcm=1.9 K, 28.4 W/m

2500 Tcm=1.9 K, 44.3 W/m

Tcm=4.5 K, 28.4 W/m 2000 300MW Tcm=4.5 K, 44.3 W/m 1500 200MW 1000

100MW 500

Total power toTotal refrigerator [W/mper beam] 0 0 50 100 150 200

Beam-screen temperature, Tbs [K] Multi-bunch instability growth time: 25 turns 9 turns (DQ=0.5)

Future Circular Collider Study Michael Benedikt 79 3rd MT Meeting, GSI Darmstadt, 31. Jan. 2017 Main SC Magnet system FCC (16 T) vs LHC (8.3 T) FCC Bore diameter: 50 mm Dipoles:

Quads: LHC Bore diameter: 56 mm Dipoles:

Quads:

Future Circular Collider Study Michael Benedikt 80 3rd MT Meeting, GSI Darmstadt, 31. Jan. 2017 Nb3Sn conductor program

Nb3Sn is one of the major cost & performance factors for FCC-hh and is given highest attention Main development goals until 2020:

2 • Jc increase (16T, 4.2K) > 1500 A/mm i.e. 50% increase wrt HL-LHC wire • Reference wire diameter 1 mm • Potentials for large scale production and cost reduction

5400 mm2 3150 mm2

~1.7 times less SC

~10% margin ~10% margin HL-LHC FCC ultimate

Future Circular Collider Study Michael Benedikt 81 3rd MT Meeting, GSI Darmstadt, 31. Jan. 2017 Collaborations FCC Nb3Sn program

Procurement of state-of-the-art conductor for protoyping:  Bruker– European  OST – US Stimulate conductor development with regional industry:  CERN/KEK – Japanese contribution. Japanese industry (JASTEC, Furukawa, SH Copper) and laboratories (Tohoku Univ. and NIMS).  CERN/Bochvar High-technology Research Inst. – Russian contribution. Russian industry (TVEL) and laboratories  CERN/KAT – Korean industrial contribution  CERN/Bruker– European industrial contribution Characterisation of conductor & research with universities:  Europe: Technical Univ. Vienna, Geneva University, University of Twente  Applied Superconductivity Centre at Florida State University New US DOE MDP effort – US activity with industry (OST) and labs

Future Circular Collider Study Michael Benedikt 82 3rd MT Meeting, GSI Darmstadt, 31. Jan. 2017 CERN-EU program ‘EuroCirCol’ on 16 T dipole design European Union Horizon 2020 program • Support for FCC study • Grant agreement 654305 • 3 MEURO co-funding

Scope:

FCC hadron collider • Optics Design • Cryo vacuum design • 16 T dipole design, construction folder for demonstrator magnets

Future Circular Collider Study Michael Benedikt 83 3rd MT Meeting, GSI Darmstadt, 31. Jan. 2017 16 T dipole options and plans

Cos-theta Common coils Swiss contribution via PSI Canted Blocks Cos-theta

• Down-selection of options end 2017 for detailed design work • Model production 2018 – 2022, • Prototype production 2023 - 2025

Future Circular Collider Study Michael Benedikt 84 3rd MT Meeting, GSI Darmstadt, 31. Jan. 2017 US Magnet Development Program

Under Goal 1:

16 T cos theta dipole design

16 T canted cos theta (CCT) design

Future Circular Collider Study Michael Benedikt 85 3rd MT Meeting, GSI Darmstadt, 31. Jan. 2017 FCC magnet technology: learning from LHC/HL-LHC

“Natural” continuation of LHC and HL-LHC programmes. Step-wise approach  each step deployed and operated in a (big) accelerator:  LHC: 8.3 T  push to ultimate field of 9 T ?

 HL-LHC: Nb3Sn technology: -- 11 T dipoles in dispersion suppression collimators -- 12-13 T peak field low-훽 quads for ATLAS and CMS IR’s

December 2015: short (1.8 m)

Nb3Sn two-in-one dipole reached 11.3 T (> nominal) without quenches

March 2016: short (1.5 m) Nb3Sn quadrupole model (final aperture =150 mm) reached current 18 kA (nominal: 16.5 kA). CERN-US LARP Collaboration (2 coils from CERN + 2 coils from US)

Fabiola Gianotti 86 FALC meeting, KEK, 24-2-2016 High-Energy LHC

FCC study continues effort on high-field collider in LHC tunnel 2010 EuCARD Workshop Malta; Yellow Report CERN-2011-1 EuCARD-AccNet- EuroLumi Workshop: The High-Energy - HE-LHC10, E. Todesco and F. Zimmermann (eds.), EuCARD-CON-2011- 001; arXiv:1111.7188; CERN-2011-003 (2011) • based on 16-T dipoles developed for FCC-hh • extrapolation from (HL-)LHC and from FCC developments • Present focus: optics scaling, infrastructure requirements & integration

Future Circular Collider Study Michael Benedikt 87 3rd MT Meeting, GSI Darmstadt, 31. Jan. 2017 lepton collider parameters

parameter FCC-ee (400 MHz) LEP2

Physics working point Z WW ZH ttbar energy/beam [GeV] 45.6 80 120 175 105 bunches/beam 30180 91500 5260 780 81 4 bunch spacing [ns] 7.5 2.5 50 400 4000 22000 bunch population [1011] 1.0 0.33 0.6 0.8 1.7 4.2 beam current [mA] 1450 1450 152 30 6.6 3 luminosity/IP x 1034cm-2s-1 210 90 19 5.1 1.3 0.0012 energy loss/turn [GeV] 0.03 0.03 0.33 1.67 7.55 3.34 synchrotron power [MW] 100 22 RF voltage [GV] 0.4 0.2 0.8 3.0 10 3.5 identical FCC-ee baseline optics for all energies FCC-ee: 2 separate rings, LEP: single beam pipe

Future Circular Collider Study Michael Benedikt 88 3rd MT Meeting, GSI Darmstadt, 31. Jan. 2017 FCC-ee exploits lessons & recipes from past e+e- and pp colliders LEP: FCC-ee high energy SR effects B-factories: KEKB & PEP-II: high beam

DAFNE currents top-up injection

VEPP2000 DAFNE: crab waist combining successful ingredients Super B-factories S-KEKB: low by*

of recent colliders → extremely KEKB: e+ source

high luminosity at high energies HERA, LEP, RHIC: Barry Barish 13 January 2011 spin gymnastics

Future Circular Collider Study Michael Benedikt 89 3rd MT Meeting, GSI Darmstadt, 31. Jan. 2017

FCC-ee optics design

Optics design for all working points achieving baseline performance Interaction region: asymmetric optics design • Synchrotron radiation from upstream dipoles <100 keV up to 450 m from IP • Dynamic aperture & momentum acceptance requirements fulfilled at all WPs

Local chromaticity correction Local chromaticity correction + crab waist sextupoles + crab waist sextupoles

IP Beam

Future Circular Collider Study Michael Benedikt 91 3rd MT Meeting, GSI Darmstadt, 31. Jan. 2017

FCC-ee dynamic aperture

Future Circular Collider Study Michael Benedikt 93 3rd MT Meeting, GSI Darmstadt, 31. Jan. 2017 FCC-ee MDI optimisation

MDI work focused on optimization of cm 20 mask 100 mrad mask

• l*, IR quadrupole design mask mask

10 • compensation & shielding solenoid c 8 d 6 • SR masking and chamber layout 4 1 3 4 5 6 7 8 9 10 QC1 meters

QC2 b QC2 a QC1

mask mask

mask mask

CERN model of BINP prototype IR quadr. CCT IR quadrupole

2 cm aperture, 100 T/m

Future Circular Collider Study Michael Benedikt 94 3rd MT Meeting, GSI Darmstadt, 31. Jan. 2017 Efficient 2-in-1 FCC-ee arc magnets

Dipole: twin aperture yoke single busbars as coils Quadrupole: twin 2-in-1 design

• Novel arrangements allow for considerable savings in Ampere- turns and power consumption

• Less units to manufacture, transport, install, align, remove,…

Future Circular Collider Study Michael Benedikt 95 3rd MT Meeting, GSI Darmstadt, 31. Jan. 2017 RF system requirements

Very large range of operation parameters

“Ampere-class” machines Naive scale up from an hh system

Vtotal nbunches Ibeam DE/turn GV mA GeV hh 0.032 500 x12 Z 0.4/0.2 30000/90000 1450 0.034 x6 W 0.8 5162 152 0.33 H 5.5 770 30 1.67 ≈ 16 x 1 cell t 10 78 6.6 7.55 400MHz, “high gradient” machines

• Voltage and beam current ranges span more than factor > 102 • No well-adapted single RF system solution satisfying requirements

Future Circular Collider Study Michael Benedikt 96 3rd MT Meeting, GSI Darmstadt, 31. Jan. 2017 RF system R&D lines

400 MHz single-cell cavities preferred for hh and ee-Z (few MeV/m) • Baseline Nb/Cu @4.5 K, development with synergies to HL-LHC, HE-LHC • R&D: power coupling 1 MW/cell, HOM power handling (damper, cryomodule)

hh Z W ≈ 16 cells per beam ≈ 100 per beam ≈ 210 per beam (+ 100 for booster ring) (+ 210 for booster ring) 400 or 800 MHz multi-cell cavities preferred for ee-ZH, ee-tt and ee-WW • Baseline options 400 MHz Nb/Cu @4.5 K, ◄▬► 800 MHz bulk Nb system @2K

• R&D: High Q0 cavities, coating, long-term: Nb3Sn like components

W H t

≈ 200 per beam ≈ 800 per beam ≈ common 2600 cells (+ 200 for booster) (+ 800 for booster) for both beams (+ 2600 for booster)

Future Circular Collider Study Michael Benedikt 97 3rd MT Meeting, GSI Darmstadt, 31. Jan. 2017 SRF R&D program topics

400/800 MHz HOM spectrum Q-slope Nb/Cu coated tailoring mitigation

Material & Assembly & cost Efficient manufacturing optimisation power sources

Future Circular Collider Study Michael Benedikt 98 3rd MT Meeting, GSI Darmstadt, 31. Jan. 2017

Muon Accelerator Program (MAP) Mark Muon based facilities and synergies Palmer Neutrino Fac13tory (NuM14AX ) Proton Driver Front End Cool- Accelera on µ Storage Ring n Factory Goal: ~10 -10 m / se 21 + - 10 m & m per year ing µ+ ν within the accelerator 5 GeV acceptance

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MW proton driver Ionization cooling Cost eff. low RF SC Detector/ Key R&D MW class target High field solenoids (30T) Fast pulsed magnet machine NCRF in magnetic field High Temp Superconductor (1kHz) interface

JP.Delahaye Unique properties of muon beams (Nov 18,2015) 3.-PIC, the Parametric Resonance Cooling of muons C. Rubbia  Combining ionization cooling with parametric resonances is expected to lead to muon with much smaller transv. sizes.  A linear magnetic transport channel has been designed by Ya.S. Derbenev et al where a half integer resonance is induced such that the normal elliptical motion of particles in x-x' phase space becomes hyperbolic, with particles moving to smaller x and larger x' at the channel focal points.  Thin absorbers placed at the focal points of the channel then cool the angular divergence by the usual ionization cooling. LEFT ordinary oscillations RIGHT hyperbolic motion x x’ = const induced by perturbations near an (one half integer) resonance of the betatron frequency.

V. S. Morozov et al, AIP 1507, 843 (2012); A Cold Muon Source: e+ on target (i.e. e+ on e- at rest)

• e+ on standard target, including crystals with channeling . Need Positrons of ~45 GeV . g(m)~200 and m laboratory lifetime of about 500 ms

• e+ on Plasma target (first simulation results were not encouraging because of the extreme density of the plasma needed)

M. Boscolo, Valencia, February 13 2017 102 Advantages: 1. Low emittance possible: Pm is tunable with √s in e+e-m+m- Pm can be very small close to the m+m- threshold 2. Low background: Luminosity at low emittance will allow low background and low n radiation (easier experimental conditions, can go up in energy) 3. Reduced losses from decay: muons can be produced with a relatively high boost in asymmetric collisions 4. Energy spread: Muon Energy spread also small at threshold, it gets larger as √s increases, one can use correlation with emission angle (eventually it can be reduced with short bunches) Disadvantages (key challenge!): use e+ ring to • Rate: much smaller cross section wrt protons reduce request on s(e+em+m-) ~ 1 mb at most positron source i.e. Luminosity(e+e-)= 1040M. cm Boscolo,-2 s G1,-1 Catania,gives 3 Dic .m 2015rates 1010 Hz

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More Disruptive Technologies: Wakefield Acceleration In summary An exciting period in front of us:  We have finished the inventory of the “known unknown”…  …but we have a vast space to explore (and a few tantalizing hints to probe)  We have a solid physics program for the next 15 – 20 years  In this time period we have to prepare for the next steps, setting directions, technologies and political frames. In summary

Experimental results will be dictating the agenda of the field. We will need: Flexibility Preparedness Visionary global policies THANK YOU