JLEIC Accelerator Concept Vasiliy Morozov on behalf of

JLEIC Accelerator Concept Vasiliy Morozov on behalf of JLEIC design team 2019 Jefferson Lab Users Organization Annual Meeting June 26, 2019

Electron Ion Collider • Recommendations in NSAC LRP 2015: 1. 2. 3. Continue existing projects: CEBAF, FRIB, RHIC. 4. “…small-scale and mid-scale projects and initiatives that enable forefront research at universities and laboratories” “…a U. S. -led ton-scale neutrinoless double beta decay experiment” “…a high-energy high-luminosity polarized EIC as the highest priority for new facility construction following the completion of FRIB” • EIC Community White Paper ar. Xiv: 1212. 1701 § Highly polarized (~70%) electron and nucleon beams § Ion beams from deuteron to the heaviest nuclei (U or Pb) § Variable center of mass energies from ~20 – ~100 Ge. V, upgradable to ~140 Ge. V § High collision luminosity ~1033 -34 cm-2 s-1 § Possibilities of having more than one interaction region 2019 Jefferson Lab Users Organization Annual Meeting 2 June 26, 2019

NAS Report • “In summary, the committee finds a compelling scientific case for such a facility. The science questions that an EIC will answer are central to completing an understanding of atoms as well as being integral to the agenda of nuclear physics today. In addition, the development of an EIC would advance accelerator science and technology in nuclear science; it would as well benefit other fields of accelerator based science and society, from medicine through materials science to elementary particle physics. ” • Topics specifically identified in the NAS report as being the main program of research at the EIC are the emergences of 1. mass of the nucleons, 2. spin of the nucleons, 3. properties of dense system of gluons from underlying QCD interactions. 2019 Jefferson Lab Users Organization Annual Meeting 3 June 26, 2019

EIC Integrated Luminosity Requirements • 2019 Jefferson Lab Users Organization Annual Meeting 4 June 26, 2019

EIC Integrated Luminosity Requirements Expanded • 2019 Jefferson Lab Users Organization Annual Meeting 5 June 26, 2019

JLEIC Status • JLEIC 100 Ge. V CM conceptual design is complete • Key features: －Modern technology －High luminosity －High polarization －Full-acceptance detection • Current work －Completion of pre-CDR-100 －Key R&D －Performance and cost optimization 2019 Jefferson Lab Users Organization Annual Meeting 6 June 26, 2019

JLEIC Layout • Electron complex － CEBAF － Electron collider ring: 3 -12 Ge. V/c • Ion complex 13 Ge. V/c High energy Booster － Ion source － SRF linac: 150 Me. V for protons － Low Energy Booster: 8. 9 Ge. V/c － High Energy Booster: 13 Ge. V/c － Ion collider ring: 200 Ge. V/c Interaction point 150 Me. V Ion lin ac Low energy 8. 9 Ge. V/c Booster 3 -12 Ge. V/c Electron collider ring Electron source 12 Ge. V CEBAF • Upgradable to 140 Ge. V CM by doubling ion energy 2012 Interaction point 100 m • Up to two detectors at minimum background locations 200 Ge. V/c Ion collider ring 2015 ar. Xiv: 1209. 0757 ar. Xiv: 1504. 07961 p. CDR August 2019 Jefferson Lab Users Organization Annual Meeting 7 June 26, 2019

Why EIC Should be Built at JLab • Large established user community in the field • CEBAF, the world highest energy CW SRF linac, as a full energy injector － Maintains highly-polarized high-current electron beam in the electron collider ring using demonstrated top-up injection technique • New collider complex －Modern design and technology －No constraints imposed by existing infrastructure －Design driven by experimental requirements • • Novel high luminosity concept Luminosity optimized around the CM range of physics interest Novel figure 8 design for high polarization of any particles including deuterons Deeply integrated detector and machine design for full acceptance －Balance of good performance and low technical risk 2019 Jefferson Lab Users Organization Annual Meeting 8 June 26, 2019

JLEIC: Key Design Concepts • 2019 Jefferson Lab Users Organization Annual Meeting 9 June 26, 2019

JLEIC Parameters and Luminosity Performance CM energy Ge. V Beam energy Collision frequency Particles per bunch Beam current Polarization RMS bunch length Norm. emitt, hori. Norm. emitt, vert. Horizontal β* Vertical β* Ge. V MHz 1010 A cm mm mrad cm cm 21. 9 p 40 e 3 p 100 476 0. 59 0. 45 85% 2. 5 0. 2 8 1. 3 Beam-beam, hori. 0. 015 Beam-beam, vert. 0. 01 Laslett tune-shift Hour-glass (HG) Peak lumi. , w/ HG Average lumi. * 0. 055 1033/cm 2 s 44. 7 3. 9 3 >85% 1 18 3. 6 30 9. 8 0. 12 0. 15 small 0. 85 3. 2 2. 3 e 5 476 0. 98 0. 75 85% 2. 5 0. 65 0. 13 8 1. 3 0. 015 0. 013 0. 018 0. 73 14. 7 10. 6 4. 7 3. 5 >80% 1 83 16. 6 5. 72 0. 93 0. 045 0. 041 small 63. 3 89. 4 98 p e 200 5 476/2=238 1. 97 6. 8 0. 75 2. 58 85% >80% 2. 1 1 0. 96 83 0. 25 16. 6 21 11. 2 1. 6 1. 1 p e 200 10 476/4=119 3. 93 4. 2 0. 75 0. 8 85% ~80% 4 1 3. 1 664 1. 5 133 21 9. 1 1. 65 p E 200 12 476/4=119 3. 93 2. 05 0. 75 0. 39 85% ~80% 4 1 3. 1 1145 1. 5 229 21 6. 6 1. 15 0. 09 0. 003 0. 02 0. 0013 0. 014 0. 008 0. 065 0. 001 0. 02 0. 0005 0. 012 0. 008 Small 0. 82 15. 5 9. 3 0. 0014 Small 0. 73 1. 9 1. 6 0. 0014 Small 0. 67 0. 86 0. 71 * Average luminosity was calculated assuming a one or two hour proton beam store without or with high energy bunched beam electron cooling plus 5 min beam formation time (mainly due to detector overhead), and a 75% duty factor of machine operation. 2019 Jefferson Lab Users Organization Annual Meeting 10 June 26, 2019

JLEIC Luminosity Performance CM Energy Main luminosity limitation low space charge medium beam-beam high synchrotron radiation 2019 Jefferson Lab Users Organization Annual Meeting 11 June 26, 2019

High Luminosity: High-Energy Electron Cooling • Magnetized electron beam for higher cooling efficiency • Cooling electron beam is energy-recovered to minimize power consumption • Circulator ring to relax electron source requirements －Fast harmonic kicker to kick electrons in and out of the circulator ring 2019 Jefferson Lab Users Organization Annual Meeting 12 June 26, 2019

High Luminosity: Beam Crabbing • Beam crossing angle is necessary to avoid parasitic collisions due to short bunch spacing, make space for machine elements, improve detection and reduce detector background Without crabbing Low luminosity Beam dynamics issues With crabbing Effective head-on collision restored Factor of 12 luminosity increase compared to uncorrected case 2019 Jefferson Lab Users Organization Annual Meeting 13 June 26, 2019

High Electron Polarization • Two highly polarized bunch trains maintained by top-off • Universal spin rotator － Minimizes spin diffusion by switching polarization between vertical in arcs and longitudinal in straights － Sequence of solenoid and dipole sections － Geometry independent of energy － Two polarization states with equal lifetimes － Basic spin match Energy (Ge. V) Lifetime (hours) E Spin Rotation Ge. V rad 3 π/2 4. 5 π/4 6 0. 62 9 π/6 12 0. 62 Arc IP • Advantage of figure-8 geometry: minimum depolarization demonstrated by spin tracking 2019 Jefferson Lab Users Organization Annual Meeting Solenoid 1 14 BDL T·m 15. 7 11. 8 12. 3 15. 7 24. 6 3 5 7 9 10 66 8 2. 2 0. 9 0. 3 Dipole Solenoid 2 set 1 set 2 Spin BDL Rotation rad T·m rad π/3 0 0 π/6 π/2 23. 6 π/4 2π/3 1. 91 38. 2 π/3 π 2π/3 62. 8 π/2 4π/3 1. 91 76. 4 2π/3 June 26, 2019

High Ion Polarization • Figure-8 concept: Spin precession in one arc is exactly cancelled in the other • Spin stabilization by small fields: ~3 Tm vs. < 400 Tm for deuterons at 100 Ge. V －Criterion: induced spin rotation >> spin rotation due to orbit errors • 3 D spin rotator: combination of small rotations about different axes provides any polarization orientation at any point in the collider ring • No effect on the orbit • Polarized deuterons • Frequent adiabatic spin flips 2019 Jefferson Lab Users Organization Annual Meeting 15 June 26, 2019

Full Acceptance Detector Concept • Would like to get ~100% acceptance for the whole event Solenoid Central Detector/ Ion bea Scattered Electron mli ne mline Electron bea Dipole d ar rw Fo Dipole n) (Io ct te De 2019 Jefferson Lab Users Organization Annual Meeting or Particles Associated with struck parton Particles Associated with Initial Ion 16 June 26, 2019

Schematic of Full-Acceptance Detector • 50 mrad crossing angle End caps • Forward hadron detection in three stages －Endcap －Small dipole covering angles up to ~3 －Far forward, ~10 mrad, for particles passing through accelerator quads Secondary focus • Low-Q 2 tagger －Small-angle electron detection Central detector 2019 Jefferson Lab Users Organization Annual Meeting Roman pots 17 June 26, 2019

• Dipole chicane for high-resolution detection of low-Q 2 electrons • Compton polarimetry has been integrated to the interaction region design －same polarization at laser as at IP due to zero net bend －non-invasive monitoring of electron polarization 2019 Jefferson Lab Users Organization Annual Meeting 18 June 26, 2019

Multi-lab Joint EIC R&D – Examples • High-Priority EIC R&D topics defined by the Jones review panel • A number of joint R&D funded by NP – FY 17, significant progress achieved in: －Crab system design and experimental test －Electron cooler design －IR magnet design －Simulation software development • Example of awarded FY 18 -19 proposals: －Crab cavity operation in a hadron ring (Lead: ODU, collaborators: JLab, BNL) －Strong hadron cooling • Development of innovative high-energy magnetized electron cooling for an EIC (Lead: JLab, collab. : BNL, FNAL, ODU) • Strong hadron cooling with micro-bunched electron beams (Lead: BNL, collaborators: JLab, SLAC, ANL) －Magnet design • High Gradient Actively Shielded Quadrupole (Lead: BNL, collaborators: JLab, LBNL) • Validation of EIC IR magnet parameters and requirements using existing magnet results (Lead: JLAB, collab. : SLAC, LBNL) －Benchmarking of EIC simulations • Development & test of simulation tools for EIC beam-beam interaction (Lead: BNL, collaborators: JLab, MSU, LBNL) • Experimental verification of spin transparency mode in an EIC (Lead: JLab, collaborator: BNL) －Electron complex • High Bandwidth Beam Feedback Systems for a High Luminosity EIC (Lead: ANL, collaborator: JLab) 2019 Jefferson Lab Users Organization Annual Meeting 19 June 26, 2019

Conclusion Courtesy of R. Yoshida • JLEIC meets or exceeds EIC requirements 2019 Jefferson Lab Users Organization Annual Meeting 20 June 26, 2019