JLEIC - An Electron-Ion Collider Proposal at Jefferson Lab Andrew - - PowerPoint PPT Presentation

JLEIC - An Electron-Ion Collider Proposal at Jefferson Lab

Andrew Hutton On behalf of the JLEIC Design Team

Overview of Jefferson Lab

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• 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
• f the structure of matter
• Through advances in fundamental

research in nuclear physics

• Through advances in accelerator

science and technology

• CEBAF has been in operation since 1995
• 12 GeV Upgrade fully completed in 2017

and delivering beam to all four Halls

• Managed for DOE by Jefferson Science

Associates, LLC (JSA)

Jefferson Lab by the numbers:

– ~725 employees – FY2016 Costs: $184.1M – FY2017 Costs: $162.1M – 169 acre site – 72 buildings/trailers; 880k SF – 1,530 Active Users – 26 Joint faculty – 562 PhDs granted to-date (200 in progress)

Jefferson Lab FY2017 Budget ($162.1M)

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LCLS II

4

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 10th arc of magnets for 5.5 pass machine
• Add 4th experimental Hall D
• New experimental equipment in Halls B, C, D

12 GeV CEBAF Upgrade Project is Complete!

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CD-4 Project Completion Approved September 27, 2017

• 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

Nuclear Physics at Jefferson Lab

Atom Consists of a nucleus surrounded by electrons A scientific mystery: No quark is ever found alone – If you try to pull two quarks apart – the energy used will transform into a quark- antiquark pair

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 Nucleus Contains protons and neutrons and is 1000 times smaller than an atom. Nucleon Three quarks bound by gluons.

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Nuclear Physics at Jefferson Lab

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Complex particle detectors Polarized electron source

GlueX in Hall D

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• New experiment to study quark confinement
• Commissioning complete
• Detector functioning well
• Production data-taking started
• Poised to discover exotic hybrid mesons

Searching for the rules that govern hadron construction

• M. R. Shepherd, J. J. Dudek, R. E. Mitchell

Co-authored by Indiana University experimenters and a JLab Scientist

Jefferson Electron-Ion Collider

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JLEIC

NSAC 2015 Long Range Plan

Recommendation I

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

Federal Advisory Committee

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Realization of an Electron-Ion Collider

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• 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

JLEIC Overview 2015

arXiv:1504.07961

• Electron complex
• CEBAF
• Electron collider ring
• Ion complex
• Ion source
• SRF linac
• Booster
• Ion collider ring
• Fully integrated IR and

detector

• DC and bunched beam

coolers Energy range: Ee: 3 to 12 GeV Ep: 40 to 100−400 GeV √s: 20 to 65−140 GeV

(upper limit depends on magnet technology choice)

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Design Fundamentals

High Luminosity

• Based on high bunch-repetition-rate and

small bunch-charge of colliding beams

• KEK-B reached > 2x1034 /cm2/s
• CEBAF provides 1.5 GHz bunch repetition

rate as electron injector

• New ion complex is also designed to deliver

high bunch repetition rate

Beam Design

• High repetition rate
• Low bunch intensity
• Short bunch length
• Small emittance

IR Design

• Very small β*
• Crab crossing

Damping

• Synchrotron radiation
• Electron cooling

High Polarization due to Figure-8

All rings are in a figure-8 shape critical advantages for both beams

• Spin precession in the left & right arcs 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

• Deuteron polarization can also be maintained

(unique feature of Figure-8)

Detection Capability

Interaction region is design to support

• Full acceptance detection (including forward

tagging)

• Low background

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Design improvements in the last year

• 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
• >1 A current in the cooling channel
• 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,
• Bunched cooling needs further study
• Smaller beta-star: β*y= 2 cm ➔ 1.2 cm
• ~60% luminosity increase
• Both detectors achieve “Full-Acceptance” and “High-Luminosity”

Enabled by significant progress in ERL cooler design and harmonic fast kicker development

Enabled by development of ion beam formation scheme Enabled by very good results of dynamic aperture studies

Fundamental design has been stable for more than a decade

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Ion Injector Complex

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Length (m)

• Max. energy (GeV/c)

SRF linac ~121 0.2 booster ~300 8 collider ring ~2150 100 (400)

• Generate, accumulate & accelerate ion beams
• Covers all required varieties of ion species
• Delivers required time and phase space

structure for matching with electron beam Half-Wave Resonator Quarter Wave Resonator

ion sources SRF linac booster collider ring cooling cooling

Ion linac (ANL) QWR HWR

Crossing: 79.8 deg. extraction injection

RF cavity kicker

booster

JLEIC Collider Rings

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• Rings have same footprint, stacked vertically with horizontal crossing angle

Arc, 261.7 IP ions 81.7 future 2nd IP

Ion ring

p e 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 Maxi dipole field T 3 ~1.5 SR power density kW/m 10 Transition tr 12.5 21.6 Natural chromaticity

• 101/-112
• 149/-123

e- Arc, 261.7 81.7 Forward e- detection IP Future 2nd IP

Super-ferric magnets Electron ring

High Luminosity: Electron Cooling

Booster (0.285 to 8 GeV) ion sources ion linac collider ring (8 to 100 GeV) Bunched and DC cooler DC cooler

Ring Cooler Function Ion energy Electron energy GeV/u MeV Booster DC Injection/accumulation

• f positive ions

0.11 ~ 0.19 (injection) 0.062 ~ 0.1 Emittance reduction 2 1.1 Collider DC Bunched Beam Maintain emittance during stacking 7.9 (injection) 4.3 Maintain emittance Up to 100 Up to 55

• DC cooling for emittance reduction and maintenance during stacking
• BBC cooling for emittance preservation against intra-beam scattering

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Strong Cooling: Circulator Ring

Electron energy MeV 20−55 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 Cooling solenoid field T 1

Fast kicker Magnetized source Enabling technologies : Fast kickers, rise time<1 ns Magnetized source ~140mA

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ion beam

ion beam magnetization flip

top ring: circulator cooling ring

Magnetized injector beam dump linac

fast extraction kicker fast injection kicker De-chirper Re-chirper circulating bunches septum vertical bend

magnetization flip

B < 0 B < 0 B > 0 B > 0 septum

bottom ring: energy recovery linac

JLEIC Parameters (3T magnets)

Center-of-Mass energy GeV 21.9 (low) 44.7 (medium) 63.3 (high) p e p e p e Beam energy GeV 40 3 100 5 100 10 Collision frequency MHz 476 476 476/4=119 Particles per bunch 1010 0.98 3.7 0.98 3.7 3.9 3.7 Beam current A 0.75 2.8 0.75 2.8 0.75 0.71 Polarization % 80 80 80 80 80 75 Bunch length, RMS cm 3 1 1 1 2.2 1

• Norm. emittance, hor./vert.

μm 0.3/0.3 24/24 0.5/0.1 54/10.8 0.9/0.18 432/86.4 Horizontal & vertical β* cm 8/8 13.5/13.5 6/1.2 5.1/1 10.5/2.1 4/0.8 Vertical beam-beam parameter 0.015 0.092 0.015 0.068 0.008 0.034 Laslett tune-shift 0.06 7x10-4 0.055 6x10-4 0.056 7x10-5 Detector space, upstream/downstream m 3.6/7 3.2/3 3.6/7 3.2/3 3.6/7 3.2/3 Hourglass(HG) reduction 1 0.87 0.75 Luminosity/IP, w/HG, 1033 cm-2s-1 2.5 21.4 5.9

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JLEIC Luminosity for Different Ion Dipoles

LHC Upgrade technology LHC technology

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JLEIC R&D Areas: Jones Panel (February 2017)

• Adopt mature technology where applicable
• Focus R&D on CTEs (critical technology elements), e.g. electron cooling
• Look at 4-5 year timeline
• Move technical readiness from “low” to “medium” in critical areas
• Properly identify high priority R&D (judgment call based on technology

readiness and impact on performance and cost)

R&D activities Higher priority topical areas for EIC R&D funding Electron Cooling ECL 8 CTE Magnets MAG 6 CTE SRF R&D SRF 3 CTE Bridge design and R&D Executed on base, LDRD and selected EIC R&D funding Injectors R&D INJ 6 CTE Interaction Regions IRS 3 CTE Beam dynamics and diagnostics BDD 8 CTE

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Planned FY18 JLEIC R&D (1)

• Strong hadron cooling using a high-current ERL
• Magnetized electron source for strong hadron cooling

Riad Suleiman

• Electron cooling simulation development

Yves Roblin

• Development of a harmonic kicker to enable use of a

circulator ring for strong hadron cooling Haipeng Wang

• SRF systems for an electron cooler

Bob Rimmer

• Design of critical technologies for ERL-based electron cooler

Steve Benson

• Validation of magnet designs by prototyping
• Complete and test a full scale suitable super-ferric magnet

Tim Michalski Support of TAMU R&D

• IR magnet design verification

Tim Michalski

• Development of IR magnet specifications for a prototype

Tim Michalski

• IR FFQ prototype design

Tim Michalski

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Planned FY18 JLEIC R&D (2)

• Crab cavity operation in a hadron ring
• Design and simulations of crab crossing and development of

crab cavity specifications Vasiliy Morozov

• Participate in the first test of crab cavity operation in a hadron ring,

SPS, at CERN Geoff Krafft

• Benchmarking of realistic EIC simulations
• Electron cooling experiment to benchmark continuous and

bunched beam electron cooling simulations Yuhong Zhang

• Further develop the design of the gear change synchronization

and assess its impact on beam dynamics Yves Roblin

• Benchmarking of ion spin tracking simulation tools

Vasiliy Morozov

• Electron complex
• High-power fast kickers for high bandwidth (2 ns bunch spacing)

feedback Bob Rimmer

• Operate the JLab CEBAF in the JLEIC injector mode

Jiquan Guo

• Benchmarking of electron spin tracking simulations

Vasiliy Morozov

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JLEIC Collaborators

• ANL & Northern Illinois University
• Ion injector design: linac, booster, electron ring as a large booster
• DESY, University of New Mexico & Cornell University
• Electron spin matching & electron spin tracking code
• Muons, Inc. & Cornell University
• Polarized ion source
• Old Dominion University
• Crab cavity design and crab crossing simulations
• Beam-beam code development
• Science and Technology Laboratory Zaryad & Moscow Institute of Physics and Technology
• Electron & ion polarization design and spin tracking
• SLAC
• Electron & ion chromaticity compensation, nonlinear dynamics optimization
• Detector region design, detector background
• Texas A&M University & LBNL
• Magnet design
• Prototype 3T super-ferric
• Collaboration with BNL strengthening
• Reaching out nationally and internationally

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JLEIC R&D Progress

• e-cooling simulation, beta-cool and new code development
• Bunched beam electron cooling at IMP
• Cooler design, preliminary design single-turn cooler
• Magnetized source, first magnetized beam in spring 2017
• Fast harmonic kicker – prototype tested successfully
• Short super-ferric prototype, mock up winding for 1.2m
• IR magnets, initial designs started
• ERL cavity, design done, prototype in progress
• Crab cavity, design started
• Spin tracking, p and e simulations validating Figure-8
• Beam beam, GHOST code development progressing

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JLEIC R&D Highlights: Electron Cooling

Institute of Modern Physics (IMP), CAS, China

DC cooler

Collaboration between JLab and IMP (China)

Thermionic gun cathode electrode

• Electron cooling to date used a DC electron beam
• Cooling by a bunched electron beam is critical for JLEIC
• Proof-of-Principle Experiment: use an existing DC cooler,

modulating the grid voltage of the thermionic gun to generate a pulsed electron beam (pulse length as short as ~100 ns)

• IMP has two storage rings, each has a DC cooler

Pulser

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JLEIC R&D Highlights: Electron Cooling

• First experiment: May 2016, bunched beam electron cooling
• bserved for the first time
• Second experiment: November 2016, machine development

(improving the beam diagnostics)

• Third experiment: April 2017, with improved electron pulses,

data still being analyzed

Experimental data observed on BPMs

cooled ion bunches uncooled ion bunches Electron pulses

Ring circumference

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Beamline Gun Solenoid Photocathode Preparation Chamber Gun HV Chamber Slit Viewer Screen Shield Tube

Magnetized Beam R&D

0 G 1511 G Measuring beam mechanical angular momentum (beam magnetization) using slit and viewer screen method with 1511 G at photocathode 1511 G

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Harmonic Fast Kicker R&D

344kV kick voltage (2.5mrad@55MeV) Baseline cavity design:

• six odd harmonics of 86.6MHz up to

952.6MHz + DC, one cavity design for all harmonics, one-pair for CCR

• High shunt impedance, <1kW @344kV per

cavity

• Asymmetric inner conductor design for the

952.6MHz mode to minimize the beam loading effect

Vz=0 on beam axis for the 952.6MHz mode

5-harmonics, copper prototype kicker Cavity, Yulu Huang, IMP/JLab PhD Thesis, 2016 Improved symmetry in gap, Sarah Overstreet summer student project 2017

New! ÷11 scheme

(Andrew Hutton/Dotson)

Ex & Ez vs z

New!

end stub preliminary Adams Institute, 18 January 2018 29

JLEIC R&D Highlights: Super-Ferric Magnet

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Fabrication of 1.2 mockup winding at Texas A&M

Peter McIntyre

JLEIC R&D highlights: CIC cable

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Fabrication of long-length Cable-In-Conduit cable on perforated center tube

Developed a custom cabler that maintains constant tension and twist pitch Completed 12 m cable

• Extensible to 125 m

JLEIC R&D Highlights: Ion Polarization

• Figure-8 concept: Spin precession in one arc is exactly cancelled in the other
• Spin stabilization by small fields: ~3 Tm versus < 400 Tm for deuterons at 100 GeV
• Criterion: induced spin rotation >> spin rotation due to orbit errors
• Polarized deuterons are only feasible with Figure-8 design
• 3D 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
• Frequent adiabatic spin flips
• Simulations in progress

n = 0

Start-to-end Zgoubi simulation of proton acceleration

𝜁𝑦,𝑧

𝑂 = 1 𝜈𝑛

𝜏𝑦,𝑧

𝑑𝑝 = 100 𝜈m

𝜉𝑡𝑞 = 0.01 𝑒𝐶 𝑒𝑢 = ~3 T/min

Zgoubi simulation of proton spin flip Adams Institute, 18 January 2018 32

JLEIC R&D Highlights: Electron Polarization

• Universal spin rotator
• Sequence of solenoids and dipoles
• Makes the spin longitudinal at IP
• Has longitudinal spin matching
• Ensures the same lifetimes for both

polarization states

• Two highly polarized bunch trains maintained by top-off injection
• Spin tracking simulations were performed, benchmarking in progress

~ 7x,y

ns=0.027 ns=0.038

Spin tracking using ZGOUBI Spin tune scan using SLICKTRACK

ns=0.027 ns=0.038

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EIC Final State Particles

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Electron beamline

Beam Elements Beam Elements

Beam elements limit forward acceptance Central Solenoid not effective for forward particles

IR & Detector Concept

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• Integrated detector region design developed, satisfying the requirements of

– Detection – Beam dynamics – Geometric match

• GEANT4 detector model developed, simulations in progress

Forward hadron spectrometer low-Q2 electron detection and Compton polarimeter

Ions

(top view in GEANT4)

electrons

ZDC

IP electrons ions

forward electron detection

Compton polarimetry

dispersion suppressor/ geometric match spectrometers forward ion detection

Detector Region

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Ion Interaction Region

limit x and y D’ ~ 0 ~14.4 m 4 m x , y < ~0.6 m middle of straight D = 0, D’ = 0

• *x,y = 10 / 2 cm, D* = D* = 0
• Three spectrometer dipoles (SD)
• Large-aperture final focusing quadrupoles (FFQ)
• Secondary focus with large D and small D
• Dispersion suppressor geometric match

IP SD1 SD2 SD3

geometric match/

• disp. suppression

FFQ

forward detection

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• Assuming beam momentum of 100 GeV/c, ultimate normalized x/y emittances

xN/yN of 0.35/0.07 m, and ultimate momentum spread p/p of 310-4

• The horizontal size includes both betatron and dispersive components

2nd focus IP

Ion Beam Envelope & Trajectory for Δp/p = -1%

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Ion Beam Dynamics

• Linear optics
• Chromaticity compensation
• Dynamic aperture

±50

with errors and correction 10 seeds collaboration with SLAC

• Momentum acceptance

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Crab Crossing in Ion Ring

• Crab cavity locations near chromatic sextupoles seem adequate

Crab 1 Crab 2 (2n+1)/(/2) 8.9995 18.9995 𝛦𝜔𝑦

(𝑑𝑠𝑏𝑐,𝐽𝑄)

4.5 π 9.5 π Bunched Beam parameters # of particles 500 εnx 0.35 m p/p 3∙10-4 σs 1 cm Gaussian distribution 3 - sigma

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Electron IR Optics

IP e- forward e- detection region FFQs FFQs Compton polarimetry region

• IR region

– Final focusing quads with maximum field gradient ~63 T/m – Four 3m-long dipoles (chicane) with 0.44 T @ 10 GeV for low-Q2 tagging with small momentum resolution, suppression of dispersion and Compton polarimeter

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Forward e- Detection & Polarization Measurement

nc

Laser + Fabry Perot cavity e- beam from IP Low-Q2 tagger for low-energy electrons Low-Q2 tagger for high-energy electrons Compton electron tracking detector Compton photon calorimeter Compton- and low-Q2 electrons are kinematically separated! Photons from IP e- beam to spin rotator Luminosity monitor

• Dipole chicane for high-resolution detection of low-Q2 electrons
• Compton polarimetry is integrated into interaction region design

– same polarization at laser as at IP due to zero net bending in between – non-invasive monitoring of electron polarization

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Detector Solenoid Effects

Effects e ring ion ring

• Coherent orbit distortion

N Y

• Coupling

Y Y

• Rotates crabbed beam planes at IP

Y Y

• Generates vertical dispersion

N Y

• Linear and non-linear optics perturbation

Y Y

• Violation of figure-8 spin symmetry

Y Y

JLEIC Detector solenoid Length 4 m (1.6 m-IP-2.4 m) Strength < 3 T Crossing Angle 50 mrad Ions electrons

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Collaborations and Plans

Collaborations

• Existing core JLEIC collaborations: SLAC, ANL, LBL, ODU, Texas A&M
• Collaboration with BNL strengthening: identified common R&D elements
• Held a joint collaboration meeting in October 2017 at BNL, to be followed by
• ne at JLAB in October 2018
• Outreach in Europe and worldwide

JLEIC Plans

• Pre-CDR ready for CD0
• CDR ready for down-select and CD1

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JLEIC Working Groups and Collaborations

• Ion injector complex / parameter development

Todd Satogata

• Ion linac

Brahim Mustapha (ANL)

• Ion and electron polarization

Fanglei Lin / Vasiliy Morozov

• Electron cooler design

Steve Benson

• Cooler magnetized electron source

Riad Suleiman

• Simulations / Instability

Yves Roblin / Rui Li

• IR / non-linear studies

Vasiliy Morozov

• Crab crossing / Crab cavity

Vasiliy Morozov / Jean Delayen (ODU)

• MDI / detector / Backgrounds

Mike Sullivan (SLAC) / Rik Yoshida

• SRF / Fast kicker

Bob Rimmer

• Engineering

Tim Michalski

• Super-ferric magnets

Peter McIntyre (Texas A&M)

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Conclusions

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• The JLEIC fundamental design has not changed in more than 10 years
• The design is optimized to maximize initial performance and minimize

technical risk

• The magnet technology to reach sqrt(s) of 140 GeV has been essentially

demonstrated at LHC

• A rich collaborative and project specific accelerator R&D program is in

progress with very encouraging results

• The EIC accelerator programs are encouraging international collaboration on

accelerator R&D