jleic - an electron-ion collider proposal at jefferson lab · jefferson lab fy2017 budget ($162.1m)...

JLEIC - An Electron-Ion Collider Proposal at Jefferson Lab

Andrew Hutton On behalf of the JLEIC Design Team

Overview of Jefferson Lab

Adams Institute, 18 January 2018 2

• 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

• 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)


LCLS II

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!


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.


Nuclear Physics at Jefferson Lab


Complex particle detectors

Polarized electron source

GlueX in Hall D


• 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


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


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

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)


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


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


Ion Injector Complex


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


• 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

of 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


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


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


JLEIC Luminosity for Different Ion Dipoles

LHC Upgrade

technology

LHC technology


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


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


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


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


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


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


JLEIC R&D Highlights: Electron Cooling

• First experiment: May 2016, bunched beam electron cooling observed 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


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


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


JLEIC R&D Highlights: Super-Ferric Magnet


Fabrication of 1.2 mockup winding at Texas A&M

Peter McIntyre

JLEIC R&D highlights: CIC cable


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

𝜀𝑥,𝑦𝑁 = 1 𝜇𝑚 𝜎𝑥,𝑦𝑐𝑜 = 100 𝜇m

𝜈𝑠𝑝 = 0.01

𝑑𝐵 𝑑𝑡 = ~3 T/min

Zgoubi simulation of proton spin flip


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

~ 7x,y

ns=0.027

ns=0.038

Spin tracking using ZGOUBI

Spin tune scan using SLICKTRACK

ns=0.027

ns=0.038


EIC Final State Particles


Electron beamline

Beam Elements Beam Elements

Beam elements limit forward acceptance

Central Solenoid not effective for forward particles

IR & Detector Concept


• 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


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


• 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 310-4

• The horizontal size includes both betatron and dispersive components

2nd focus

IP

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


Ion Beam Dynamics

• Linear optics • Chromaticity compensation

• Dynamic aperture

±50

with errors and correction

10 seeds

collaboration with SLAC

• Momentum acceptance


Crab Crossing in Ion Ring

• Crab cavity locations near chromatic sextupoles seem adequate

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

𝛥𝜓𝑥(𝑐𝑟𝑎𝑏,𝐼𝑃)

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


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


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


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


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 one at JLAB in October 2018

• Outreach in Europe and worldwide

JLEIC Plans • Pre-CDR ready for CD0

• CDR ready for down-select and CD1


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)


Conclusions


• 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

jleic - an electron-ion collider proposal at jefferson lab · jefferson lab fy2017 budget ($162.1m)...

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