JLEIC - An Electron-Ion Collider Proposal at Jefferson Lab Andrew Hutton On behalf of the JLEIC Design Team
Overview of Jefferson Lab • Jefferson Lab was created to build and operate the Continuous Electron Beam Accelerator Facility (CEBAF), a unique user facility for Nuclear Physics • Mission is to gain a deeper understanding of the structure of matter • Through advances in fundamental research in nuclear physics • Through advances in accelerator science and technology Jefferson Lab by the numbers: – ~725 employees • CEBAF has been in operation since 1995 – FY2016 Costs: $184.1M – FY2017 Costs: $162.1M • 12 GeV Upgrade fully completed in 2017 – 169 acre site and delivering beam to all four Halls – 72 buildings/trailers; 880k SF – 1,530 Active Users • Managed for DOE by Jefferson Science – 26 Joint faculty Associates, LLC (JSA) – 562 PhDs granted to-date (200 in progress) Adams Institute, 18 January 2018 2
Jefferson Lab FY2017 Budget ($162.1M) LCLS II Adams Institute, 18 January 2018 3
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12 GeV CEBAF Upgrade Project is Complete! Total Project Cost = $338M • Double maximum Accelerator energy to 12 GeV • Ten new high gradient cryomodules • Double Helium refrigerator plant capacity • Civil construction and upgraded utilities • Add 10 th arc of magnets for 5.5 pass machine • Add 4 th experimental Hall D • New experimental equipment in Halls B, C, D • All KPPs (Key Performance Parameters) exceeded technical requirements, and the last KPP was completed 5 months ahead of schedule • Project completed ~$2.4M under budget • Project has been nominated for a DOE Secretary's Excellence Award CD-4 Project Completion Approved September 27, 2017 Adams Institute, 18 January 2018 5
Nuclear Physics at Jefferson Lab Jefferson Lab acts as a large microscope! Probing the nucleus with electrons allows scientists to “see” inside matter. We want to know how ordinary matter is put together Atom Consists of a nucleus surrounded by electrons Nucleus Contains protons and neutrons and is 1000 times smaller than an atom. A scientific mystery: No quark is ever found alone – If Nucleon you try to pull two quarks apart – Three quarks bound by the energy used will transform gluons. into a quark- antiquark pair Adams Institute, 18 January 2018 6
Nuclear Physics at Jefferson Lab Complex particle detectors Polarized electron source Adams Institute, 18 January 2018 7
GlueX in Hall D • New experiment to study quark confinement • Commissioning complete • Detector functioning well Searching for the rules that govern • hadron construction Production data-taking started • M. R. Shepherd, J. J. Dudek, R. E. Mitchell Poised to discover exotic hybrid mesons Co-authored by Indiana University experimenters and a JLab Scientist Adams Institute, 18 January 2018 8
Jefferson Electron-Ion Collider JLEIC Adams Institute, 18 January 2018 9
NSAC 2015 Long Range Plan Recommendation I Federal Advisory Committee The progress achieved under the guidance of the 2007 Long Range Plan has reinforced U.S. world leadership in nuclear science. The highest priority in this 2015 Plan is to capitalize on the investments made Recommendation II We recommend the timely development and deployment of a U.S.-led ton-scale neutrinoless double beta decay experiment Recommendation III We recommend a high-energy high-luminosity polarized EIC as the highest priority for new facility construction following the completion of FRIB Recommendation IV We recommend increasing investment in small-scale and mid-scale projects and initiatives that enable forefront research at universities and laboratories Adams Institute, 18 January 2018 10
Realization of an Electron-Ion Collider • Both Jefferson Lab and Brookhaven National Lab are proposing to build an electron-ion collider • Jefferson Lab wants to add an ion complex to CEBAF • BNL wants to add an electron complex to RHIC • Only one, at most, will be built • The present timeline is as follows: • 2018 National Academy completes evaluation of the physics case • 2018 – 19 ? DOE may consider CD-0, “Approve Mission Need” • 2019 – 21 ? Down-select will/may occur • 2022 ? Construction could start • In the meantime, JLab and BNL are working together on common R&D • Many other laboratories are collaborating • This talk will only address the Jefferson Lab proposal – JLEIC Adams Institute, 18 January 2018 11
JLEIC Overview Energy range: E e : 3 to 12 GeV E p : 40 to 100−400 GeV √s: 20 to 65−140 GeV (upper limit depends on magnet technology choice) • Electron complex • CEBAF • Electron collider ring • Ion complex • Ion source • SRF linac • Booster • Ion collider ring 2015 • Fully integrated IR and detector • DC and bunched beam coolers arXiv:1504.07961 Adams Institute, 18 January 2018 12
Design Fundamentals High Luminosity High Polarization due to Figure-8 • Based on high bunch-repetition-rate and All rings are in a figure-8 shape small bunch-charge of colliding beams critical advantages for both beams Spin precession in the left & right arcs of the ring are exactly cancelled • KEK-B reached > 2x10 34 /cm 2 /s Net spin precession (spin tune) is zero, thus energy independent Beam Design Spin can be controlled & stabilized by small • High repetition rate solenoids or other compact spin rotators • Low bunch intensity • Short bunch length Deuteron polarization can also be maintained • Small emittance (unique feature of Figure-8) Damping IR Design • Very small β * • Synchrotron radiation Detection Capability • Crab crossing • Electron cooling Interaction region is design to support Full acceptance detection (including forward • CEBAF provides 1.5 GHz bunch repetition tagging) rate as electron injector • New ion complex is also designed to deliver Low background high bunch repetition rate Adams Institute, 18 January 2018 13
Design improvements in the last year Fundamental design has been stable for more than a decade • New electron ring: new magnets, same footprint • Reaches 12 GeV ➔ 70 GeV Center-of-Mass • 3 possible optics designs (FODO, TME, multiple bend achromat lattices) • Same synchrotron radiation (10 kW/m, ~10MW) • Strong cooling is back: circulator cooler ring Enabled by significant progress in ERL cooler design and harmonic • >1 A current in the cooling channel fast kicker development • Circulator ring, up to 11 turns, ~100 mA in ERL • Higher stored ion current/bunch intensity: 500 mA ➔ 750 mA • Up to 50% luminosity increase • Seems OK with ion injector/DC cooling, Enabled by development of ion • Bunched cooling needs further study beam formation scheme Enabled by very good results of • Smaller beta-star: β * y = 2 cm ➔ 1.2 cm dynamic aperture studies • ~60% luminosity increase • Both detectors achieve “Full - Acceptance” and “High -Luminosity ” Adams Institute, 18 January 2018 14
Ion Injector Complex • Generate, accumulate & accelerate ion beams cooling • Covers all required varieties of ion species cooling collider SRF ion • Delivers required time and phase space ring linac sources booster structure for matching with electron beam Ion linac (ANL) QWR HWR booster Quarter Wave Resonator Half-Wave Resonator RF cavity kicker Length (m) Max. energy (GeV/c) Crossing: SRF linac ~121 0.2 79.8 deg. booster ~300 8 extraction injection collider ring ~2150 100 (400) Adams Institute, 18 January 2018 15
JLEIC Collider Rings • Rings have same footprint, stacked vertically with horizontal crossing angle Ion ring Super-ferric magnets Arc, 261.7 81.7 future 2 nd IP ions IP p e Electron ring Circumference m 2154 Crossing angle degree 81.7 Lattice FODO FODO Dipole & quad m 8 & 0.8 5.4 & 0.45 Cell length m 22.8 15.2 81.7 e - Future Arc, Maxi dipole field T 3 ~1.5 2 nd IP 261.7 SR power density kW/m 10 IP Transition tr 12.5 21.6 Forward e - detection Natural chromaticity -101/-112 -149/-123 Adams Institute, 18 January 2018 16
High Luminosity: Electron Cooling Bunched ion sources and DC ion linac DC cooler cooler Booster collider ring (0.285 to 8 GeV) (8 to 100 GeV) Ring Cooler Function Ion energy Electron energy GeV/u MeV Injection/accumulation 0.11 ~ 0.19 0.062 ~ 0.1 of positive ions (injection) Booster DC Emittance reduction 2 1.1 Maintain emittance 7.9 DC 4.3 during stacking (injection) Collider Bunched Maintain emittance Up to 100 Up to 55 Beam DC cooling for emittance reduction and maintenance during stacking BBC cooling for emittance preservation against intra-beam scattering Adams Institute, 18 January 2018 17
Strong Cooling: Circulator Ring top ring: circulator cooling ring ion beam magnetization flip magnetization flip ion beam B > 0 B > 0 B < 0 B < 0 linac beam dump Magnetized injector fast extraction kicker fast injection kicker septum septum circulating bunches De-chirper Re-chirper vertical bend bottom ring: energy recovery linac Enabling technologies : Fast kickers, rise time<1 ns 20−55 Electron energy MeV Magnetized source ~140mA Bunch charge nC Up to 3.2 Turns in circulator ring turn ~11 Current in CCR/ERL A 1.5/0.14 Bunch repetition MHz 476 Cooling section length m 4x15 Magnetized Cooling solenoid field T 1 source Fast kicker Adams Institute, 18 January 2018 18
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