An Overview of New Electron-Ion Collider Proposals

Transcription

1 An Overview of New Electron-Ion Collider Proposals Yuhong Zhang Thomas Jefferson National Accelerator Facility (Jefferson Lab) High Energy Physics Program, HKUST Jockey Club Institute of Advanced Study, The Hong Kong University of Science and Technology 9-26 Jan 2017

2 2 Outline Introduction: EIC in A Global Prospect US Proposals: erhic and JLEIC European Proposal: LHeC Emerging Energy Frontier: FCC-he and CEPC-SPPC-he Highlights on Accelerator R&D Summary Electron-ion collider (EIC) = electron-proton collisions (e-p) + electron-(light to heavy) ion collisions (e-a)

3 Electron-Ion Collider: The Next Generation HERA, the only e-p collider ever built and operated, ended its science program in Over the last ten years, 7 next generation electron-ion colliders have been envisioned worldwide for high energy physics and nuclear physics. Five proposals are based on existing or under construction facilities which provide one of two colliding beams. Other two are positioned as an extra capability of new energy frontier e+e- and pp colliders Driven by the science programs, each of the new proposals focuses on a distinct CM energy range from a few tens GeV to above TeV, aims for delivering much higher performances (luminosity, polarization, etc.) than HERA. 3

4 The World 1 st ep Collider 4 A Ring-Ring (polarized) Lepton-Proton collider with 320 GeV CM energy Tunnel: 6.3 km 5.2 m diameter H1 ZEUS

5 The World 1st ep Collider 1981 Proposal 1984 Start construction Milestones over 26+ years 1991 Commissioning, 8 years first Collisions 1992 Start Operations for H1, ZEUS 1 st results w/ low luminosity 1994 Install East Spin Rotators polarized leptons for HERMES 1996 Install 4 th Interaction region for HERA-B 1999 High Luminosity Run with electrons 2000 High efficient luminosity production: 100 /pb/y 13 years 2001 Luminosity upgrade, spin rotators for H1 and ZEUS 2003 Longitudinal polarization in high energy collisions 2007 End of a highly successful program (Waiting for new ideas for reusing the facility) Lepton Proton Energy GeV CM energy GeV 318 Intensities ma 60 Up to 42 e-polarization % 30 to Final luminosity cm -2 s -1 (1.5 to 4)x10 31 HERA 1: ~ HERA 2: ~ 4x pb -1 integrated luminosity delivered Superconducting proton ring Normal conducting ring for e± Ring circumference: 6.3 km Two collision experiments: H1, ZEUS One internal target: HERMES (27.6 GeV e± on gas jet, H, D, Kr ) Longitudinal (self) polarization 5

6 New Electron-Ion Colliders on World Map FAIR ENC RHIC erhic CEBAF JLEIC LHC LHeC HIAF CEPC-SPPC-ep FCC-he 6

7 EIC Science with Deep Inelastic Scatterings The Nuclear Science of and Explore Hadron Structure Map the spin and spatial structure of valence & sea quarks in nucleons The Nuclear Science of ~12 GeV CM energy 20 to 140 GeV CM energy Explore and Understand QCD Map the spin and spatial structures of quarks and gluons in nucleons Discover the collective effects of gluons in atomic nuclei (role of gluons in nuclei & onset of saturation) Understand the emergence of hadronic matter from quarks and gluons & EW The High-Energy Science of LHeC Presently not active ~TeV CM energy lepton-proton at the TeV Scale a very affordable Higgs facility Hunt for quark substructure & high-density matter (saturation) High precision QCD and EW studies and precision Higgs measurements Energy Frontier FCC-he and CEPC-SPPC-he Still under development Higgs potential and exotic Higgs, Beyond standard model (Leptoquarks, heavy neutrinos..) Parton dynamics at high scales and very small xbj Multi-TeV CM energy 7

8 Electron-Nucleon Collider FAIR Facility for Antiproton & Ion Research (FAIR)@GSI P A ring-ring collider Use High Energy Storage Ring (HESR) for storing 15 GeV proton beam Add an electron storage ring for 3 GeV, 2 A beam Share PANDA detector HESR e-ring p-ring Head-on collision Baseline: β*=30 cm 2x10 32 /cm 2 s Aggressive: β*=10 cm 6x10 32 /cm 2 s With traveling focusing /cm 2 s e - PANDA Polarize e-injector Polarized e-source Electron injector 3.3 GeV Vision: Electron Nucleon FAIR Conventional electron cooling 8 PANDA

9 EIC at HIAF, Institute of Modern Physics, China High Intensity Heavy Ion Accelerator Facility Institute of Modern Physics, China 5 Aiming for multi-science program 1 Low energy nuclear structure spectrometer 6 2 Low energy RIBs beam station High precision spectrometer High purity & quality RIBs station Electron-ion recombination resonance spectrometer High energy irradiation terminal 7 High-Energy-Density Matter terminal 2 8 External target station Low energy: 3 GeV e to 12 GeV p 12 GeV CM Polarized beams Figure-8 shape collider rings Peak luminosity: up to 4x10 32 /cm 2 /s 9

10 Outline Introduction: EIC in A Global Prospect US Proposals: erhic and JLEIC European Proposal: LHeC Emerging Energy Frontier: FCC-he and CEPC-SPPC-he Highlights on Accelerator R&D Summary 10

11 Gluons and the EIC: In Media 11 Scientific American May 2015

12 Electron-ion Collider as The Next QCD Frontier A Gluon Microscopy for Understanding the Glue that Binds Us All Nuclei Luminosity (cm -2 sec -1 ) 3D Imaging Integrated Luminosity (fb -1 /yr) An EIC, with a versatile range of beam species, kinematics, polarizations, and high luminosity, is required to precisely image the sea quarks and gluons in nucleons and nuclei, to explore the new QCD frontier of strong color fields in nuclei to resolve outstanding issues in understanding nucleons and nuclei in terms of fundamental building blocks of QCD A. Deshpande, Stony Brook Univ Parton QCD at Extreme Distributions in Parton Densities - Nuclei Saturation Tomography (p/a) Transverse Momentum Distribution and Spatial Imaging Spin and Flavor Structure of the Nucleon and Nuclei Inclusive Semi- Inclusive R. Ent, Jefferson Lab S (GeV)

13 US NSAC Long Range Plan (LRP) NSAC (Nuclear Science Advisory Committee) is commissioned by the US Department of Energy and the National Science Foundation It provides advices on assessment and prioritization of the national program for basic nuclear science research. Presently it has 19 members, all leading scientists in US universities and national laboratories, and international institutions Every 6 to 8 years, NSAC produces a Long Range Plan (LRP), with 3 to 5 recommendations, basically it is a roadmap for large nuclear science facilities in US for the next 10 years LRP 1979, 1983, 1989, 1996, 2002, 2007, 2015 To be selected as one recommendation in LRP 2015 is a Necessary and (Nearly?) Sufficient Step toward the Final Construction of An Electron-Ion Collider in US 13

14 US NSAC Long Range Plan NSAC LRP 1996 RHIC remains our highest construction priority. NSAC LRP 2002 The Rare Isotope Accelerator (RIA) is our highest priority for major new construction We strongly recommend the upgrade of CEBAF at Jefferson Lab to 12 GeV as soon as possible NSAC LRP 2007 We recommend completion of the 12 GeV CEBAF Upgrade at Jefferson Lab. We recommend construction of the Facility for Rare isotope Beams, FRIB NSAC LRP 2015 We recommend a high-energy high-luminosity polarized Electron-Ion Collider for new facility construction following the completion of FRIB Released Oct. 15, 2015 Last Step of the process for approval of EIC: National Academy of Science Review (in progress) 14

15 Science White Paper, Design Requirements and Challenges EIC White Paper General Requirements High polarized (~70%) electron and nucleon beams Ion beams from deuteron to the heaviest nuclei (uranium or lead) Variable center of mass energies from ~1000x ~20 - ~100 higher GeV, than HERA upgradable to ~140 GeV Whole HERA 1 done in High collision luminosity ~ /cm 2 /s one day Possibilities of having more than one interaction Whole HERA 2 done in one week 180 pages Uniqueness and design challenges Asymmetric collider (energy aspect ratio: up to ~50) Collisions of leptons and (wide range of) hadrons Variable energies Large center-of-mass energy range (20 to 100/140 GeV) Polarized beams (electron, and proton/light ions up to Li) Very high luminosity (100 x larger than HERA) Full-acceptance forward detection 15

16 Two Labs Competing for the US EIC BNL JLab erhic JLEIC Needs an electron beam Needs a proton/ion beam Based on RHIC and its injector complex polarized proton and 3He, up to 250 GeV/u other all-stripped ions, up to gold 100 GeV/u Add a polarized electron beam up to 18 GeV A recirculating ERL (linac-ring design) A storage ring (ring-ring design) Based on CEBAF recirculated SRF linac polarized electron beam up to 12 GeV, Add ion injector and two storage rings (ring-ring design) Polarized proton, deuteron and 3He Up to 100 GeV/u 16

17 Relativistic Heavy Ion Collider (RHIC) Electron accelerator to be build Unpolarized & polarized PHENIX e± :00 (30) o clock GeV e - e - e + LINAC 70% e - beam polarization EBIS NSRL Booster BLIP Electron lenses 10:00 o clock Polarized protons p GeV Polarized electrons AGS with E e 30 GeV will collide with either polarized protons with E e 325 GeV or heavy ions E A 130 GeV/u Achieved peak luminosities: Au Au (100 GeV/n) cm -2 s -1 electrons p p (255 GeV) cm -2 s -1 Light ions (d,si,cu) Heavy ions (Au,U) GeV/u STAR Polarized 6:00 o clock light ions He GeV/u protons Other large hadron colliders (scaled to 255 GeV): Tevatron (p pbar) cm -2 s -1 LHC (p p) cm -2 s -1 RHIC Tandems Brief History Polarized Jet Target 12:00 o clock st erhic paper (Electron cooling) 2:00 o clock st White Paper on erhic 2003 appears in DoE s Facilities for the Future Sciences: A Twenty Year Outlook 2004 Zeroth-Order Design Report with cost estimate for Ring-Ring 2007 Operated Linac-ring modes (beam became energies): baseline Au Au U U (~10-fold higher luminosity) 2008 first staging option of erhic Cu Cu p p 2009 completed design, and cost d Au* 100 GeV/n estimate for MeRHIC with 4 GeV ERL Cu Au* Present Planned or - returned possible future to all modes: in tunnel design Au Au with 2.5 staging GeV/n electron energy p A* 100 GeV/n (A = Au, Cu, Al) from 10 to 30 GeV 17 RF 4:00 o clock 3.8/4.6/5.8/10/14/32/65/100 GeV/n 96.4 GeV/n 11/31/100 GeV/n 11/31/100/205/250/255 GeV 100 GeV/n 3 He A* 100 GeV/n (A = Au, Cu, Al) p 3 He * 166 GeV/n (*asymmetric rigidity)

18 erhic Approach for High Luminosity: Linac(ERL)-Ring Ring-ring: æ L = 4pg hg e ö ç x h x e è r h r e ø Linac-ring: ( ) f ( ) s h' s e ' L = g h f N h x h Z h b h * r h RHIC RHIC Electron storage ring x e ~ 0.1 Electron linear accelerator x e >1 Natural staging strategy L x 50(?) In a linac-ring collider, a lepton beam can tolerate much higher beam-beam perturbations since the beam is not stored/reused in a ring, Thus it could (at least theoretically) achieved a much higher luminosity than a ringring collider of same collision frequency and other beam parameters ERL provides a practical way to accelerate high current beam with a low RF power 18

19 erhic Ultimate Design: ERL-Ring Add an recirculating ERL Design has gone several round of major revisions for cost-performance optimization The latest one is Non-Scaling Fixed-Field Alternating Gradient (NS-FFAG) Two FFAG for 16 passes of linac 1 st FFAG: 5 passes # GeV # GeV # GeV # GeV # GeV SRF Linac GeV 2 nd FFAG: 11 passes # GeV # GeV # GeV # GeV # GeV # GeV # GeV # GeV # GeV # GeV # GeV 19

20 Performance of Ultimate Linac-Ring erhic 20

21 Coherent Electron Cooling (CeC) A novel concept proposed by Ya. Derbenev, further developed by V. Litvinenko/Ya. Derbenev Fundamentally a stochastic cooling, with a similarly modulator/pickup & correcter/kicker setup However, using SASE FEL mechanism for signal amplification much wide frequency range orders of magnitude improvement of cooling rate A critical ingredient of the ultimate linac-ring erhic design, one of the most challenging R&D: technology (e-source/beam) and proof-of-concept modulator Amplifier (via High Gain FEL) undulator kicker 21

22 Optimization: Acceptable Technical Risk F. Willeke Achievable Luminosity with proven technology in the range of /cm 2 /s will provide access to compelling initial physics program The reduced luminosity goal makes a storage ring based collider (RR) an interesting alternative to and multi-turn ERL based concept. Strategy towards erhic Design Study simultaneously two solutions, both based on existing technology: multi-turn ERL (LINAC-Ring collider, LR) Low-risk storage ring based collider (Ring-Ring Luminosity Luminosity R&D collider RR) Carry Linac-Ring ~10 common R&D elements (e.g. crab cavity) 33 /cm in 2 /s ~10 34 /cm 2 /s Down parallel Future design Work on experimental verification selection of critical, 1 st yet phase to be demonstrated upgrade Ultimate design elements (polarized electron source, SRF Linac) erhic linac-ring R&D Carry Ring-Ring erhic out Value Engineering and R&D which might lead to cost saving (FFAG lattice with CBETA, design No cooling (coherent electron Gatling electron R&D Gun, Waveguide HOM damper) Performance, cooling, Based Compare on the existing two options in terms of performance, cost and residual risk, and feasibility of Cost, Galting gun) high luminosity upgrade technology Residual risk High lumi upgrade Select a final erhic conceptual design as soon as possible Pursue R&D program addressing CeC, to pave the way for a high luminosity upgrade. 22

23 Features of (Low Risk) erhic Linac-Ring Design Measures for risk reduction Maximum electron energy: 18 GeV 50 ma polarized electron source employing merging electron current produced by multiple photo-cathode guns no galting gun Main ERL SRF linac(s): 647 MHz cavities, 3 GeV/turn Six individual re-circulation beamlines based on electromagnets (like 12 GeV CEBAF), not FFAG No hadron cooling (CeC) required for e-p in initial design. Existing stochastic cooling system can be used for e-au Luminosity upgrade to the Ultimate design: add a cooling (CeC) 3 GeV 6 GeV 9 GeV 12 GeV 15 GeV 18 GeV Conventional CEBAF-like Interaction region design with crab-crossing satisfying detector acceptance requirements Individual photo-cathode guns Traditional multi-gun design 8 individual photo-cathode gun Merged together to form a single gun with 8 time higher current 23

24 Features of the (Low Risk) Ring-Ring erhic Design A new electron complex A storage-collider ring (5 to 18 GeV) o inside the RHIC tunnel o Higher beam current (up to 1.3 A) o SR limited to 10 MW o Flat beam (due to SR) o 3 times more bunches (333 vs. 111) o Robinson wiggler in straight section for emittance controlling (low energy) A full energy polarized e-injector o An electron SRF linac (6 GeV) (SRF enables future upgrade to linac-ring) o 3-pass recirculating beam lines (conventional, like CEBAF, not FFAG) o Inside the RHIC tunnel (cost saving) o Top-off injection Crossing angle collision geometry (22 mrad) requiring crab cavities Bunch-to-bunch spin sign control by full energy injector and frequent electron bunch replacement Injector based on low current polarized gun, small accumulator ring recirculating SRF linac for low beam current (4mA), runs at 1 Hz, doesn t need energy recovery e-gun 0.4 GeV Linac 1 (3 GeV ) 24 Linac 2 (3 GeV)

25 erhic Luminosity Performance Ultimate Linac-Ring Ring-Ring Low-risk Linac-Ring erhic is designed for an ultimate luminosity of L = cm -2 s -1 but it needs Strong Hadron Cooling to reach full luminosity Low risk design started to reduce overall technical risk 25

26 (1 st Phase) erhic Design Parameters About 30 times higher than HERA 26

27 CEBAF Fixed Target Program at JLab 5-pass recirculating SRF linac 12 GeV max energy SRF Linac CEBAF Arc 11 GeV max energy Hall D Hall B 27

28 JLEIC: A Ring-Ring EIC at JLab 3-10 GeV 8 GeV GeV Electron complex CEBAF Electron collider ring Ion complex Ion source and linac Booster Ion collider ring Two detectors 2012 Brief History st paper on JLab EIC proposal: An ERL-Ring design based on CEBAF 2003 ERL based circulator e-cooler 2006 Baseline changed to ring-ring th Order Design Report 2009 Medium energy as the baseline with a future energy upgrade option st Design Report released 2014 Baseline revised for cost optimization 2 nd Design Report released 2015 erhic/jleic Joint Cost Review 2016 erhic/jleic Joint R&D Review

29 Strategy for Achieving High Performance High Luminosity Based on high bunch repetition rate CW colliding beams n n n n L f ~ f * * * x y y KEK-B reached > 2x10 34 /cm 2 /s However new for proton or ion beams Beam Design High repetition rate Low bunch charge Short bunch length Small emittance IR Design Small β* Crab crossing Damping Synchrotron radiation Electron cooling High Polarization w/ Figure-8 All rings are in a figure-8 shape critical advantages for both beams Spin precessions in the left & right parts of the ring are exactly cancelled Net spin precession (spin tune) is zero, thus energy independent Spin can be controlled & stabilized by small solenoids or other compact spin rotators Excellent Detection Capability Interaction region is design to support Full acceptance detection (including forward tagging) Low detector background 29

30 JLEIC Baseline Parameters CM energy GeV 21.9 (low) 44.7 (medium) 63.3 (high) p e p e p e Beam energy GeV Collision frequency MHz /4=119 Particles per bunch Beam current A Polarization % Bunch length, RMS cm Norm. emitt., hor./vert. μm 0.3/0.3 24/24 0.5/0.1 54/ / /86.4 Horizontal & vertical β* cm 8/8 13.5/13.5 6/ /1 10.5/2.1 4/0.8 Vert. beam-beam param Laslett tune-shift x x x10-5 Detector space, up/down m 3.6/7 3.2/3 3.6/7 3.2/3 3.6/7 3.2/3 Hourglass(HG) reduction Luminosity/IP, w/hg, cm -2 s Future Energy Upgrade Options Ion ring magnet to 6 T (Super-ferric): CM energy up to ~100 GeV Ion ring magnet to 8.3 T (LHC): CM energy up to ~118 GeV Ion ring magnet to 12 T (TBD): CM energy up to ~140 GeV 30

31 JLEIC e-p Luminosity 31

32 Achieved JLEIC Design Goals Energy Full coverage of CM energy from 15 to 65 GeV Electrons 3-10 GeV, protons GeV, ions GeV/u Ion species Polarized light ions: p, d, 3 He, and possibly Li Un-polarized light to heavy ions up to A above 200 (Au, Pb) Support 2 detectors Full acceptance capability is critical for the primary detector Luminosity to cm -2 s -1 per IP in a broad CM energy range Polarization At IP: longitudinal for both beams, transverse for ions only All polarizations >70% Upgrade to higher energies and luminosity possible Design goals consistent with the EIC White Paper requirements 32

33 JLEIC Electron Collider Ring 33 D x (m) Layout w/ major machine components IP Ring Optics Arc, Future 2 nd IP e - x (m), y (m) Forward e - detection Cost efficient design Reuse PEP-II high energy collider ring equipment (magnets, vacuum and RF) A figure-8 shape for the same footprint as the ion collider ring & good polarization Support two detectors & all insertions (lowbeta, spin rotators, RF, injection, chromatic compensation, etc.) IP Parameters Unit Value Circumference m 2154 Crossing angle deg 81.7 Lattice type FODO Dipole & quad length m 5.4 / 0.45 Cell length (PEP-II) m 15.2 SR power & density MW, kw/m Up to 10, 10 Transition gamma tr 21.6 Natural chromaticity -149 / -123

34 A New Ion Complex for JLEIC Generate/accumulate & accelerate ion beams Covering all required varieties of ion species Matching time, spatial and phase space structure of the ion beam with electron beam Length (m) Max. energy (GeV/c) SRF linac 0.2 booster ~300 8 collider ring ~ QWR Quarter Wave Resonator (QWR) Ion linac HWR Half-Wave Resonator (HWR) ion sources SRF linac cooling booster (accumulator) cooling collider ring ARC 3 booster ARC 1 RF Cavities Solenoids 34 ARC 2 Beam from LINAC

35 D x (m) 35 JLEIC Ion Complex: Collider Ring Layout w/ major machine components Using super-ferric magnets (up to 3T) A figure-8 shape for high ion polarization ions 81.7 IP future 2 nd IP Arc, Stacked above the electron ring; ions travel to the plane of electron ring in vertical chicanes for collisions Supports two detectors and all insertions (low-beta, spin elements, RF, e-cooling, injection, chromatic compensation) Super-ferric magnets Parameters Values Circumference m 2154 Crossing angle deg 81.7 x (m), y (m) ions Arc 1 Straight 1 IP Arc 2 Straight 2 Arc 1 Optics Lattice type FODO Dipole & quad length m 8 & 0.8 Cell length m 22.8 Maximum field T 3 Transition gamma tr Natural chromaticity -101 / -112

36 JLEIC Multi-Step Cooling Scheme 36 Cooling of the JLEIC protons/ions Achieve a small emittance and a short bunch length of 1 to 2 cm (with strong SRF) Enable ultra strong final focusing and crab crossing Suppress intra-beam scatterings (IBS), maintaining beam emittance & luminosity lifetime JLEIC adopts conventional electron cooling Well established technology (in the low energy DC regime) Needs two coolers for multi-step cooling Low-energy DC cooler: within state-of-the-art, similar to the 2 MeV COSY cooler High-energy BB cooler: using SRF linac & ERL technology, currently under development Ring Cooler Function Ion energy Electron energy Booster Collider DC BBC (Bunched Beam) accumulation of positive ions GeV/u 0.11 ~ 0.19 (injection) MeV ~ 0.1 Emittance reduction Maintain emittance during stacking 7.9 (injection) ~ 2 cool z 4d 4.3 Maintain emittance Up to 100 Up to 55

37 DC Cooler & Bunched Beam ERL Cooler DC cooler (at low energy) Design specifications Magnetized beam Energy: 0.11 to 1.1 MeV Current: 2 A Cooling section: 10 m Within the present state-of-art Well developed and low cost, Recent experience: 2 MeV COSY cooler (built by Budker Institute and successfully commissioned) BB cooler (at high energy) Design challenges Cooling by a bunched beam Magnetized beam High current: ~ 1 A High bunch charge: ~ Choice of technology ERL A technical design of cooler and R&D is underway COSY, IKP, Jülich 36

38 Outline Introduction: EIC in A Global Prospect US Proposals: erhic and JLEIC European Proposal: LHeC Emerging Energy Frontier: FCC-he and CEPC-SPPC-he Highlights on Accelerator R&D Summary 38

39 LHeC Physics Program M. Klein arxiv: , and 5102 Ultra high precision (detector, e-h redundancy) Maximum luminosity and much extended range Deep relation to (HL-) LHC (precision+range) - new insight - rare, new effects - complementarity 39

40 LHeC Options and Down Selection F. Zimmermann RR LHeC: new ring in LHC tunnel, with bypasses around Existing experiments LR LHeC: Recirculating linac w/ energy recovery, or straight linac RR LHeC e-/e+ injector 10 GeV, 10 min. filling time Ring-ring Chavannes LHeC 2012 can workshop: be built, no principal problem fund Integration Decision in tunnel to focus & co-existence future activities with LHC on ERL hardware option are which very allows challenging Installation construction is very challenging and installation Independent of LHC schedule! 40

41 LHeC: Linac(ERL)-Ring 41 recirculating linac Two 10 GeV SRF linacs (944 cavities; 59 modules per linac) 3 accelerating/decelerating passes in CW operation (~4500 magnets) 9 km underground tunnel SRF sees 6*current at the IP 4 ns bunch spacing Why ERL? High energy, high current beams require 0.1 to 1 GW RF system in conventional linacs ERL alleviates extreme RF power demand nearly independent of beam current ERL maintains superior beam quality: emittance, energy spread, short bunches

42 LHeC Parameters CDR Study assumptions: Parallel operation to HL-LHC TeV Scale collision energy GeV Beam Energy Limit power consumption to 100 MW (beam & SR power < 70 MW) 60 GeV beam energy Peak Luminosity > cm -2 s GeV > cm -2 s cm -2 s -1 Luminosity reach cm -2 sprotons -1 Luminosity Electrons reach Protons Electrons Beam Energy [GeV] Beam Energy 7000 [GeV] Luminosity [10 33 cm -2 s -1 ] Luminosity [10 33 cm s -1 ] 1 Normalized emittance ge x,y [mm] Normalized emittance 2.5 ge x,y 20 [mm] Beta Funtion b * x,y [m] Beta Funtion 0.05 b * x,y [m] rms Beam size s * x,y [mm] rms Beam size 4 s * x,y [mm] rms Beam divergence s * x,y [mrad] rms Beam divergence 80 s * x,y 40 [mrad] Beam IP[mA] Beam Current IP [ma] (860) 6.6 Bunch Spacing [ns] Bunch Spacing 25 [ns] (50) 25 (50) Bunch Population Bunch Population 2.2* * *10 11 (1*10 9 ) 2*10 9 Bunch charge [nc] Bunch charge 35 [nc] (0.16)

43 Recirculating ERL Design 43 Vertical separation of arcs y [cm] Spreader 1, 3 and 5 Arc 1 (10 GeV) T 60 GeV 50 0 Arc 3 (30 GeV) Arc 5 (50 GeV) T 40 GeV Multi-pass ER optics: linac 1 & 2 z [cm] T 20 GeV detector A. Bogacz ERL2015, June 9, 2015

44 Outline Introduction: EIC in A Global Prospect US Proposals: erhic and JLEIC European Proposal: LHeC Emerging Energy Frontier: FCC-he and CEPC-SPPC-he Highlights on Accelerator R&D Summary 44

45 EIC at Energy Frontier FCC CepC-SppC Circular e+e- or hh collider Proton: up to 50 TeV Electron: up to 175 GeV Ring circumference: 100 km Circular e+e- or hh collider Proton: up to 35 TeV Electron: up to 120 GeV Ring circumference: 50 km 50 TeV 100 km 50 MW RF power per e± beam 2 interaction points 50 MW RF power per e± beam 2+2 interaction points e-p/a collisions: up to GeV electron x 50 TeV protons up to 120 GeV electron x TeV protons 45

46 FCC-he: General Considerations Infrastructure does not aim for FCC-ee and FCC-hh being in the tunnel at the same time FCC-he: LHeC recirculating ER electron linac FCC-hh collider ring Physically relocate LHeC electron linac (from LHC ring to FCC ring) FCC-he will operate at the same time as the two main FCC experiments and potentially more experiments FCC-hh design Baseline Ultimate CMS energy [TeV] Luminosity [10 34 /cm 2 s] 5 20 Bunch distance [ns] 25 (5) Bunch charge [10 11 ] 1 (0.2) Norm. emitt. [mm] 2.2 (0.44) RMS bunch length [cm] 8 IP beta-function [m] IP beam size [mm] 6.8 (3) 3.5 (1.6) Max ξ for 2 IPs 0.01(0.02) 0.03 ep must not significantly compromise the main experiments Detector concept derived from detailed LHeC detector design Proton equilibrium emittance decreases due to SR damping 46

47 (Preliminary) FCC-he Parameters protons electrons beam energy GeV Luminosity, cm -2 s /13.7->7.3/10.7 normalized emittance mm 2.2 -> /10 IP beta function mm /42 -> 48/52 rms IP beam size mm /1.9 -> 2.9/2.1 Waist shift [mm] mm 0 65/65 -> 60/70 beam current [ma] ma 500-> bunch spacing ns bunch population > Under investigation o What is the electron bunch charge limit? o Is the proton beta-star of 30 cm possible? o Can the electron beta-function be achieved? o Is the impact of the beam-beam effects on both beams acceptable? 47

48 CepC-SppC e-p/a Design Consideration Assumption: NO upgrade of CepC-SppC for realizing e-p/a e-p/a performance is determined by beams from CepC-SppC CepC e+e- collisions and e-p/a collision can t be run simultaneously Each CepC lepton beam has only 50 bunches due to the one-ring design while one proton beam in SppC has 3000 to 6000 bunches CepC lepton beam is extreme flat (aspect ratio ~330) while a SppC proton is basically flat, it is very difficult to have the spot sizes of two beams matched Without the constraint of running e+e- and e-p/a collisions simultaneously, the electron beam in CepC can be reconditioned to match the proton beam for optimizing the e-p/a collision luminosity Increase electron bunches to 3000 Reduce the emittance aspect ratio to make it a round beam Double the beam current (still under 100 MW SR power budget) This early design has not been synchronized with the recent change of CepC-SppC baseline (100 km, double ring) 48

49 (Preliminary) CepC-SppC e-p Parameters Operational scenario e-p and pp e-p only Particle Proton Electron Proton Electron Beam energy TeV CM energy TeV Beam current ma Particles per bunch Number of bunch Bunch spacing ns Bunch repetition rate MHz Normalized emittance, (x/y) μm rad Bunch length, RMS cm Beta-star (x/y) cm Beam spot size at IP (c/y) μm Beam-beam per IP(x/y) Crossing angle mrad ~0.8 ~0.8 Hour-glass (HG) reduction Lumi. per IP, w/ HG reduction /cm 2 /s

50 VHEeP: EIC at Extreme High Energy (9.2 TeV) A. Caldwell, M. Wing, UCLA/DESY/U. Hamburg Science motivation: what science for an e-p collider at ~10 TeV CM energy Can be tests for standard model and QCD? Can explore gluon saturation (with extreme small x)? Accelerator technology: plasma wake-field acceleration One LHC beam for collision, ~up to 7 GeV Another LHC beam as a driven beam for accelerating a electron beam (3 TeV) This will be similar to a linac-linac collider, CM energy ~9 TeV driven beam Colliding beam Plasma wake-field accelerator Accelerator design concept 3000 bunches per beam in LHC LHC beam filling time 30 min Bunch collision frequency: 2 Hz One proton bunch accelerates one electron bunch Bunch intensity: 4x10 11 (p), 1x10 11 (e) Strong final focusing: beam spot size 4 µm Luminosity: ~4x10 28 /cm 2 /s@9.2 TeV cm 1 st VHEeP Workshop this year 50

51 Outline Introduction: EIC in A Global Prospect US Proposals: erhic and JLEIC European Proposal: LHeC Emerging Energy Frontier: FCC-he and CEPC-SPPC-he Highlights on Accelerator R&D Summary 51

52 PERLE: Powerful ERL Orsay Supports LHeC linac-ring A test facility for Demonstration of high current multi-turn energy recovery Up to 3 turns, 200 (400) MeV linac, up to 10 ma Development of ER technologies 802 MHz SRF technology Science programs A collaboration of BINP, CERN, Daresbury, JLab, Liverpool, Orsay (LAL/IPN) TDR during 2017 Parameters Dipoles per arc Dipole length (cm) Max B field (T) Quadrupoles per arc Quadrupoles in straight Dipoles in spreader/combiner Quads in spreader/combiner Value 3/ Dipoles for injection-extraction 6 52

53 High Energy ER Experiment at CEBAF A JLab-BNL collaboration This experiment supports both low-risk and ultimate erhic linac-ring design Will perform energy-recovery up to 7 GeV (limited by SR) 1 pass up (accelerating) and 1 pass down (decelerating) 3 pass up and 3 pass down 5 pass up and 5 pass down Energy recovery is achieved by changing phase of returning pass at entry of the linac (using a dogleg chicane) 53

54 54 CBETA: A Test Facility for FFAG Based ERL A collaboration of BNL and Cornell U. Support the ultimate linac(erl)-ring erhic design (China) It will test the high current (but low energy) FFAG based ERL An ERL with a single 4-pass FFAG-like recirculating arc The test facility is at Cornell, using existing infrastructure 6 MeV low-emittance, high current photo-injection 36 MeV SRF linac New permanent magnets used for recirculating arc The facility can also be used to test HOM damping with high current, replacing linac with erhic linac cryostat $25M funding from NY State has been approved White paper arxiv:

55 CeC Proof-of-Principle Experiment at RHIC This experiment supports the ultimate erhic linacring design (for achieving /cm 2 s) Only one gold bunch in RHIC will be cooled Experiment is in progress since 2012 Phase1 of the equipment and most of infrastructure are installed into RHIC s IP2 Beam from the SRF gun (3 nc, 1.7 MeV) exceeds performance of all operating CW guns Species Au +79 Ion energy GeV/u 40 Ion bunch intensity Electron energy MeV Charge per e-bunch nc 0.5 to 5 Rep rate khz e-beam current ma MeV SRF linac and helical wigglers for FEL amplifier are installed Schedule during RHIC Run 17 (2018) Beam dump CeC 1 20 MeV linac 2 MeV Gun

56 Test Facility for ERL-Circulator Cooler at JLab Demonstrate the ERL-Circulator cooler design concept injector Develop/test key technologies (magnetized gun, fast kickers, etc.) Study dynamics of the cooling bunches in a circulator ring Using the existing ERL without upgrade, adding a new ring Supporting to deliver high luminosity (up to 2x /cm 2 /s), Cooler Test LERF Dump 56

57 57 Experimental Demonstration of Bunched Beam Cooling A collaboration of JLab, IMP (China) All electron cooling to this day were performed using a DC electron beam Cooling by a bunched electron beam is considered one critical R&D for the JLEIC baseline Proof-of-Principle Experiment: using an existing DC cooler, utilizing a method of modulating grid voltage of a thermionic gun to generate a pulsed electron beam (pulse length as short as ~100 ns) Institute of Modern Physics (IMP), CAS, China IMP has two storage rings, each has a DC cooler Thermionic gun cathode DC cooler electrode Pulser

58 Bunched Beam Cooling Was Demonstrated cooled ion bunches uncooled ion bunches Experiment data observation on BPMs Ring circumference Electron bunches The 1st experiment was carried out last May at IMP. The bunched beam electron cooling was observed for the 1 st time The 2 nd experiment was scheduled at the end of Nov. 2016, primarily for machine development (beam diagnostics improvement) The 3 rd experiment is likely at April or May, 2017, for pushing for better electron pulses (including short pulse length and better pulse shape) 58

59 Outline Introduction: EIC in A Global Prospect US Proposals: erhic and JLEIC European Proposal: LHeC Emerging Energy Frontier: FCC-he and CEPC-SPPC-he Highlights on Accelerator R&D Summary 59

60 A New World of Electron-Ion Collider Max Klein, Univ. of Liverpool Updated by Yuhong Zhang HIAF ENC JLEIC 2 JLEIC erhic 2 erhic HERA LHeC-HF FCC-he LHeC CepC- SppC-ep 60 VHEeP

61 61 Envisoned JLEIC Timeline Activity Name GeV Operations 12 GeV Upgrade FRIB EIC Physics Case NSAC LRP NAS Study CD0 EIC Design, R&D Pre-CDR, CDR CD1(Down-select) CD2/CD3 EIC Construction pre-project Pre-CDR on-project CDR CD0 = DOE Mission Need statement; CD1 = design choice and site selection (VA/NY) CD2/CD3 = establish project baseline cost and schedule

62 erhic Possible Timeline F. Willeke 62

63 Summary A class of new electron-ion colliders have been proposed worldwide for future high energy and nuclear physics research. Both the science programs and the accelerator designs are under development. All new EIC accelerator designs aim for high performance, orders of magnitude better than HERA, to meet science needs. In order to deliver the high performance, a class of new technologies have been integrated into the conceptual designs; resulting in high demands on technology R&D. 63

64 Acknowledgement I took slides liberally from many colleagues who were involved in these new EIC proposals: LHeC/FCC-he: Oliver Bruning, Max Klein, Daniel Schulte erhic: ENC: HIAF: VHEeP: Christoph Monteg, Vladimir Litvinenko, Vadim Ptitsyn, Thomas Roser, Ferdinand Willeke Kurt Aulenbacher Jiangchen Yang Allen Caldwell I want to thank these colleagues I also want to thank the Jefferson Lab EIC team and many collaborators. 64