Future Plans at Jefferson Lab: 12 GeV Upgrade and ELIC Allison Lung - - PowerPoint PPT Presentation

Future Plans at Jefferson Lab: 12 GeV Upgrade and ELIC

Allison Lung Jefferson Lab

DIS 2008 University College London April 8, 2008

OUTLINE

• 12 GeV Upgrade:

– Jefferson Lab Today and Tomorrow – Highlights of Science Program – Project Status

• ELIC:

– Joint EIC Development – Jefferson Lab Science Beyond 12 GeV Upgrade – ELIC Design Approach – Next Steps

• eRHIC talk (B. Surrow)

Jefferson Lab Today

2000 member international user community engaged in exploring quark- gluon structure of matter

A C

Superconducting accelerator provides 100% duty factor beams of unprecedented quality, with energies up to 6 GeV CEBAF’s innovative design allows delivery of beam with unique properties to three experimental halls simultaneously Each of the three halls offers complementary experimental capabilities and allows for large equipment installations to extend scientific reach

B

A B C Jefferson Lab Today

Two high-resolution 4 GeV spectrometers Large acceptance spectrometer electron/photon beams 7 GeV spectrometer, 1.8 GeV spectrometer, large installation experiments

Hall A Hall B Hall C

Page 5

6 GeV CEBAF 11

12

Two 0.6 GV linacs 1.1

CHL CHL-

• 2

2

Upgrade magnets Upgrade magnets and power and power supplies supplies Enhanced capabilities in existing Halls Lower pass beam energies still available

Thomas Jefferson National Accelerator Facility

Hall D Calo Rev Feb 19, 2008

WBS 1.6.3 Hall D Complex (Rendering)

Hall D Counting House Cryo Plant Tagger Area Service Building

N

Photon Beam Dump

Operated by the Southeastern Universities Research Association for the U.S. Department of Energy

Thomas Jefferson National Accelerator Facility

Overview of Upgrade Technical Performance Requirements

Hall D Hall B Hall C Hall A excellent hermeticity luminosity 10 x 1034 energy reach installation space polarized photons hermeticity precision Eγ ∼8.5−9 GeV 11 GeV beamline 108 photons/s target flexibility good momentum/angle resolution excellent momentum resolution high multiplicity reconstruction luminosity up to 1038 particle ID

Hall D Hall D – – exploring origin of exploring origin of confinement confinement by by studying studying exotic mesons exotic mesons Hall B Hall B – – understanding understanding nucleon structure nucleon structure via via generalized generalized parton parton distributions distributions Hall C Hall C – – precision determination of precision determination of valence quark valence quark properties in nucleons and nuclei properties in nucleons and nuclei Hall A Hall A – – short range correlations, form factors, short range correlations, form factors, hyper hyper-

• nuclear physics, future

nuclear physics, future new experiments new experiments

12 GeV Capabilities

International & NSF & State:

Non-DOE Hardware Contributions

• International:

– EU Proposal: Hall B Central Detector – NIKHEF/Armenia: HERMES lead glass blocks – Canada NSERC:

• Hall D Barrel Calorimeter (partial labor)
• Hall C Gas Cerenkov
• National Science Foundation (NSF):

– Hall C Detector System – Hall B Central Time-of-Flight Detector

• Commonwealth of Virginia:

– Hall D Complex: civil construction Red = proposed Green = confirmed

Highlights of the 12 GeV Science Program

• Unlocking secrets of QCD: quark confinement
• New and revolutionary access to the structure of

the proton and neutron

• Discovering the quark structure of nuclei
• High precision tests of the Standard Model

DIS 2008 Talks:

• S. Niccolai (Orsay): GPDs
• P. Souder (Syracuse): Parity Violating DIS

Gluonic Excitations and the Origin

• f

Confinement

QCD predicts a rich spectrum of as yet to be discovered gluonic excitations - whose experimental verification is crucial for our understanding of QCD in the confinement regime. With the upgraded CEBAF, a linearly polarized photon beam, and the GlueX detector, Jefferson Lab will be uniquely poised to:

• discover these states,
• map out their spectrum, and
• measure their properties

New, comprehensive view of hadronic structure

Quark Structure of Nuclei

• (Nucleons and Pions) or (Quarks and Gluons)?
• Not a simple convolution of free nucleon structure with Fermi motion
• In nuclear deep-inelastic scattering, we look directly at the quark structure of nuclei

12 GeV Upgrade Provides Substantially Enhanced Access to the DIS Regime

Counts/hour/ (100 MeV)2 (100 MeV2) for L=1035 cm-2 sec-1

Measuring High-x Structure Functions

REQUIRES:

– High beam polarization – High electron current – High target polarization – Large solid angle spectrometers

12 GeV will access the regime (x > 0.3), where valence quarks dominate

12 GeV - $310M Total TPC - Jul-2007

• 10,000

The 12 GeV Upgrade Project: Status and Schedule

12 GeV PHYSICS FY07 FTEs BY MONTH

• 5

FTEs

Compelling Physics

DOE Generic Project Timeline

We are here

Nov 2007

⎬

1 year

Sept 2008

DOE Project Critical Decisions

• CD-0 Approve Mission Need
• CD-1 Approve Alternative Selection and Cost Range
• Permission to develop a Conceptual Design Report
• Defines a range of cost, scope, and schedule options
• CD-2 Approve Performance Baseline
• Fixes “baseline” for scope, cost, and schedule
• Now develop design to 100%
• Begin monthly Earned Value progress reporting to DOE
• Permission for DOE-NP to request construction funds
• CD-3 Approve Start of Construction
• CD-4 Approve Start of Operations or Project Close-out

Thomas Jefferson National Accelerator Facility

DIS2008 April 8, 2008

DOE CRITICAL DECISION SCHEDULE

CD-0 Mission Need MAR-2004 (A) CD-1 Preliminary Baseline Range FEB-2006 (A) CD-2 Performance Baseline NOV-2007 (A) CD-3 Start of Construction SEP-2008 CD-4A Accelerator Project Completion and Start of Operations DEC-2014 CD-4B Experimental Equipment Project Completion and Start of Operations JUN-2015

(A) = Actual Approval Date

CD-4 split in two to ease transition into operations phase

12 GeV Upgrade

2004-2005 Conceptual Design (CDR) - finished 2004-2008 Research and Development (R&D) - ongoing 2006 Advanced Conceptual Design (ACD) - finished 2006-2009 Project Engineering & Design (PED) - ongoing (based on baseline funding guidance approved by DOE-NP in Nov 2007)

12 GeV Upgrade: Phases and Schedule

2009-2013 Construction – starts in ~ 6-9 months!

Parasitic machine shutdown – May 2011 through Oct 2011 (6 months) Accelerator shutdown start mid-May 2012 Accelerator commissioning mid-May 2013

2013-2015 Pre-Ops (beam commissioning)

Hall A commissioning start ~October 2013 Hall D commissioning start ~April 2014 Halls B and C commissioning start ~October 2014

12 GeV Upgrade: Phases and Schedule

CD-3 September ’08 Construction Start October ‘08

• Requirements
• Finish remaining R&D
• Develop all Designs to 80% to 100% maturity
• July 22nd - 24th : Critical Decision 3 Review
• SC Independent Project Review (IPR): conducted by Dan Lehman (DOE SC

Office of Project Assessment)

• JLab Program Advisory Committee
• Two reviews to date of 12 GeV proposals – “commissioning experiments”
• Key step in identifying the research interests and participation of international

collaborators

12 GeV Upgrade Summary

• Essential to address key questions in hadronic physics
• Broad and diverse scientific program
• Unique and complementary kinematic reach and capabilities
• Strong opportunity for international collaboration
• 12 GeV Project: Construction start in ~6-9 months
• Critical Decision 2 in September 2007 (baseline)
• Critical Decision 3 in September 2008 (construction start)
• We are on track for accomplishing this!

Import v3

• EIC Evolution
• Primary Science Goals
• EIC in the NSAC 2007 Long Range Plan
• Two Designs: ELIC / eRHIC schematics
• Science Motivation
• Expected research highlights
• At turn-on
• (e,p) and (e,A)
• ELIC Accelerator Design
• Design Goals
• Design Features
• Accelerator R&D
• Summary – next steps

JLab Beyond 12 GeV Upgrade

ELIC

Science Motivation

A High Luminosity, High Energy Electron-Ion Collider: A New Experimental Quest to Study the Glue which Binds Us All How do we understand the visible matter in our universe in terms of the fundamental quarks and gluons of QCD?

Explore the new QCD frontier: strong color fields in nuclei

How do the gluons contribute to the structure of the nucleus? What are the properties of high density gluon matter? How do fast quarks or gluons interact as they traverse nuclear matter?

Precisely image the sea-quarks and gluons in the nucleon

How do the gluons and sea-quarks contribute to the spin structure of the nucleon? What is the spatial distribution of the gluons and sea quarks in the nucleon? How do hadronic final-states form in QCD?

Electron Ion Collider (EIC)

• Build a gluon microscope to investigate using the

tools of deep-inelastic scattering:

– precise image of gluons in nucleon and nuclei – spin structure of proton – complete image through GPDs

• Facility Parameters:

– high energy – variable energy – high collision rates – beams of heavy nuclei – light ion beams & spin pol. protons colliding with…. – polarized e - & e +

The EIC Working Group

• 17C. Aidala, 28E. Aschenauer, 10J. Annand, 1J. Arrington, 26R. Averbeck, 3M. Baker, 26K. Boyle,
• 28W. Brooks, 28A. Bruell, 19A. Caldwell, 28J.P. Chen, 2R. Choudhury, 10E. Christy, 8B. Cole, 4D. De

Florian, 3R. Debbe, 26,24-1A. Deshpande, 18K. Dow, 26A. Drees, 3J. Dunlop, 2D. Dutta, 7F. Ellinghaus, 28R. Ent, 18R. Fatemi, 18W. Franklin, 28D. Gaskell, 16G. Garvey, 12,24-1M. Grosse- Perdekamp, 1K. Hafidi, 18D. Hasell, 26T. Hemmick, 1R. Holt, 8E. Hughes, 22C. Hyde-Wright, 5G. Igo,

• 14K. Imai, 10D. Ireland, 26B. Jacak, 15P. Jacobs, 28M. Jones, 10R. Kaiser, 17D. Kawall, 11C. Keppel,
• 7E. Kinney, 18M. Kohl, 9H. Kowalski, 17K. Kumar, 2V. Kumar, 21G. Kyle, 13J. Lajoie, 16M. Leitch,
• 27A. Levy, 27J. Lichtenstadt, 10K. Livingstone, 20W. Lorenzon, 145. Matis, 12N. Makins, 6G. Mallot,
• 18M. Miller, 18R. Milner, 2A. Mohanty, 3D. Morrison, 26Y. Ning,
• 15G. Odyniec, 13C. Ogilvie, 2L. Pant,
• 26V. Pantuyev, 21S. Pate, 26P. Paul, 12J.-C. Peng, 18R. Redwine, 1P. Reimer, 15H.-G. Ritter, 10G.

Rosner, 25A. Sandacz, 7J. Seele,

• 12R. Seidl, 10B. Seitz, 2P. Shukla, 15E. Sichtermann, 18F. Simon,
• 3P. Sorensen, 3P. Steinberg, 24M. Stratmann, 22M. Strikman, 18B. Surrow, 18E. Tsentalovich,

11V.

Tvaskis, 3T. Ullrich, 3R. Venugopalan, 3W. Vogelsang, 28C. Weiss, 15H. Wieman,15N. Xu,3Z. Xu,

• 8W. Zajc.

1Argonne National Laboratory, Argonne, IL; 2Bhabha Atomic Research Centre, Mumbai, India; 3Brookhaven National Laboratory, Upton, NY; 4University of Buenos Aires, Argentina; 5University of California, Los Angeles, CA; 6CERN, Geneva, Switzerland; 7University of Colorado,

Boulder,CO; 8Columbia University, New York, NY; 9DESY, Hamburg, Germany; 10University of Glasgow, Scotland, United Kingdom; 11Hampton University, Hampton, VA; 12University of Illinois, Urbana-Champaign, IL; 13Iowa State University, Ames, IA; 14University of Kyoto, Japan;

15Lawrence Berkeley National Laboratory, Berkeley, CA; 16Los Alamos National Laboratory, Los Alamos, NM; 17University of Massachusetts,

Amherst, MA; 18MIT, Cambridge, MA; 19Max Planck Institüt für Physik, Munich, Germany; 20University of Michigan Ann Arbor, MI; 21New Mexico State University, Las Cruces, NM; 22Old Dominion University, Norfolk, VA; 23Penn State University, PA; 24RIKEN, Wako, Japan; 24-1RIKEN-BNL Research Center, BNL, Upton, NY; 25Soltan Institute for Nuclear Studies, Warsaw, Poland; 26SUNY, Stony Brook, NY; 27Tel Aviv University, Israel;

28Thomas Jefferson National Accelerator Facility, Newport News, VA

95 Scientists, 28 Institutions, 9 countries

27

Available at:

• NSAC LRP2007 home page
• Rutgers Town Meeting page
• http://www.bnl.gov/eic

EIC White Papers 2007

The Electron Ion Collider (EIC)

White Paper

The GPD/DVCS White Paper Position Paper: e+A Physics at an

Electron Ion Collider

The eRHIC machine: Accelerator

Position Paper

ELIC ZDR Draft

• C. Aidala, NSCL, March 12, 2008

2007 Long Range Plan

US Department of Energy Office of Science Office of Nuclear Physics Nuclear Science Advisory Committee (NSAC)

• C. Aidala, NSCL, March 12, 2008

2007 Long Range Plan

Two Machine Designs Under Study

ELIC

JLab ELIC: Add ion beam facility to existing 12 GeV e- facility

• Ee

= 9 GeV

• EA

= 90 GeV (up to Au)

• L ~ 1.6 x 1035

eRHIC

(ERL-based) linac-ring design BNL

PHENIX STAR

e-cooling (RHIC II) Four e-beam passes Main ERL (2 GeV per pass)

eRHIC: Add energy recovery linac to existing RHIC

• Ee

= 10 (20) GeV

• EA

= 100 GeV (up to U)

• L ~ 2.9 x 1033

Sample of Research Highlights of EIC at turn-on

= x/xIP

• Syst. studies of F2

(A,x,Q2):

• precision measurement of

G(x,Q2)

• distinguish between

models of shadowing

Diffractive studies in eA:

• Distinguish between linear

evolution and saturation models

• Insight into the nature of

the pomeron

Initial studies of g1 (x,Q2):

• Constrain unknown low-x

behavior

• Superb sensitivity to Δg

at small x

33

The First 5 Years (e+A only)

• First measurement from scaling violations of nuclear gluon distributions (for Q2

> 2 GeV2 and x < 10-2 down to 5·10-4 in 20+100 configuration). Comparison to (i) DGLAP based shadowing and (ii) saturation models. (20 weeks-year 1 measurement)

• Study of centrality/A dependence of nuclear quark and gluon distributions.

Comparison to model predictions. Extract A dependence of Qs in saturation framework (would require more than 1 species in year 1)

• First measurement of charm distributions in cold nuclear matter - energy loss

(from Au over proton, or better deuteron). Consistency check of extracted gluon distributions to that from scaling violations.

• First measurement of FL in nuclei at small x (will complement e+p PRL on wide

extension of measured range). Extraction of gluon distribution, test of higher twist effects, saturation... (will require energy scan)

• First measurement of diffractive structure function in nuclei F2

D - study of

scaling violations of F2

D with Q2. (year 1-low luminosity measurement)

• Precision measurements of elastic J/ψ production - detailed tests of color

transparency/opacity DIS2008 Talks:

• B. Surrow

(MIT): eRHIC

• J. Bluemlein

(DESY-Zeuthen): polarised pdfs

• A. Sandacz

(Warsaw): GPD program

• M. Lamont (BNL): eA

program

Page 34

Spin Structure of the Nucleon

We know from lepton scattering experiments over the last three decades that:

• quark contribution ΔΣ

≈ 0.3

• gluon contribution ΔG ≈

1 ± 1

• Δu > 0, Δd < 0, Δs ~ 0
• measured anti-quark polarizations are consistent with zero

½ = ½ ΔΣ + ΔG + Lq + Lg

Proton helicity sum rule:

ΔG: a “quotable” property of the proton (like mass, momentum contrib., …)

( However, Q2 dependent: )

Page 35

World Data on F2

p

HERA F2

1 2 3 4 5 1 10 10 2 10 3 10 4 10 5

F2

em

• log10(x)

Q2(GeV2)

ZEUS NLO QCD fit H1 PDF 2000 fit H1 94-00 H1 (prel.) 99/00 ZEUS 96/97 BCDMS E665 NMC x=6.32E-5 x=0.000102 x=0.000161 x=0.000253 x=0.0004 x=0.0005 x=0.000632 x=0.0008 x=0.0013 x=0.0021 x=0.0032 x=0.005 x=0.008 x=0.013 x=0.021 x=0.032 x=0.05 x=0.08 x=0.13 x=0.18 x=0.25 x=0.4 x=0.65

World Data on g1

p

T h e d r e a m i s t

• p

r

• d

u c e a s i m i l a r E I C p l

• t

f

• r

g

1

( x , Q

2

)

• v

e r s i m i l a r x a n d Q

2

r a n g e

Region of existing g1

p

data An EIC makes it possible! See LRP for nice plot of g1

p

vs Q2 w/curves and error bands from global QCD fit by Boetcher & Bluemlein

Page 36

ELIC Accelerator Design Goals ELIC Accelerator Design Goals

Center-of-mass energy between 20 GeV and 90 GeV: with energy asymmetry of ~10, which yields (Ee ~ 3 GeV

• n EA

~ 30 GeV) up to (Ee ~ 9 GeV

• n EA

~ 225 GeV) Average Luminosity from 1033 to 1035 cm-2 sec-1 per Interaction Region Ion Species: Polarized H, D, 3He, possibly Li Ions up to A = 208 Polarization: Longitudinal for both beams in the interaction region Transverse polarization of ions Spin-flip of both beams All polarizations >70% desirable Positron Beam desirable

Page 37

ELIC Study Group & Collaborators ELIC Study Group & Collaborators

• A. Afanasev, E. Aschenauer, J. Benesch, A. Bogacz, P. Brindza, A. Bruell,
• L. Cardman, Y. Chao, S. Chattopadhyay, E. Chudakov, P. Degtiarenko, J.

Delayen, Ya. Derbenev, R. Ent, P. Evtushenko, A. Freyberger, D. Gaskell, J. Grames, A. Hutton, R. Kazimi, G. Krafft, R. Li, L. Merminga, J. Musson, M. Poelker, R. Rimmer, A. Thomas, H. Wang, C. Weiss, B. Wojtsekhowski, B. Yunn, Y. Zhang

• Jefferson Laboratory
• W. Fischer, C. Montag
• Brookhaven National Laboratory
• V. Danilov
• Oak Ridge National Laboratory
• V. Dudnikov
• Brookhaven Technology Group
• P. Ostroumov
• Argonne National Laboratory
• V. Derenchuk
• Indiana University Cyclotron Facility
• A. Belov
• Institute of Nuclear Research, Moscow, Russia
• V. Shemelin
• Cornell University

Page 38

ELIC Conceptual Design

3-9 GeV electrons 3-9 GeV positrons 30-225 GeV protons 15-100 GeV/n ions

Green-field design of ion complex directly aimed at full exploitation of science program.

p r e b

• s

t e r

12 GeV CEBAF Upgrade

Page 39

ELIC Ring-Ring Design Features

Directly aimed at optimizing the science program:

Electron cooling is an essential part of ELIC

Low emittance and short ion bunches

Short ion bunch advantages:

Strong beam focusing at collision point Enables crab crossing colliding beams High rep rate

Four IPs (detector space ± 3 m) for high science productivity “Figure-8” ion and lepton storage rings

Ensure spin preservation and ease of spin manipulation No spin sensitivity to energy for all species

Unprecedented high luminosity

Enabled by short ion bunches, low β*, high rep. rate

Page 40

ELIC Ring-Ring Design Features (cont’d.)

Present CEBAF gun/injector meets storage-ring requirements

True Ring-Ring design where polarized source/injector beam requirements met (state-of-the-art ~0.1 mA)

The 12 GeV CEBAF serves as a full energy injector to electron ring Simultaneous operation of collider and CEBAF fixed target program Experiments with polarized positron beam are possible

Page 41

ELIC R&D Requirements

• To achieve luminosity at 1033

cm-2 sec-1 and up

High energy electron cooling

• To achieve luminosity at ~ 1035

cm-2 sec-1

Crab cavity

Configuration optimization achieved (see next slide)

Stability of intense ion beams

Studying multiphase cooling approach

Beam-beam interactions

Simulations in progress

Detector R&D for high repetition rate (1.5 GHz)

Page 42

IP Configuration Optimization:

• “Lambertson”-type final focusing quad

angle reduction: 100 mrad 22 mrad decrease crab cavity voltage requirement by reducing crossing angle

ELIC R&D: Crab Crossing

magnetic Field in cold yoke around electron pass. Cross section of quad with beam passing through

10 cm 14cm 3cm 1.8m 20.8kG/cm 4.6cm 8.6cm

Electron (9GeV) Proton

(225GeV) 2.4cm 10cm 2.4cm 3cm 4.8cm

1st SC focusing quad for ion

JLab engineer:

• P. Brindza

Page 43

ELIC Summary

• A compelling scientific case has developed for an electron ion

collider to address fundamental questions in hadronic physics

• Complements definitive study of valence region at JLab

12 GeV

• Two machine designs are under study –

ELIC and eRHIC

• JLab

design studies have led to ELIC:

• Ring-Ring approach uses CEBAF as full energy e-

injector and can be integrated with 12 GeV fixed target program

• Includes heavy ions, 20 < ECM

< 90 GeV

• Lp

at or above 1035 cm-2 sec-1 (per nucleon) possible

• Lp

up to 1033 cm-2 sec-1 can be achieved with state-of-the-art technology, except for electron cooling

• JLab

is committed to collaborative approach for developing science case and optimal technical design for a next generation EIC

• NEXT STEPS……

Page 44

EIC: Next Steps

• Pre-R&D Plan:
• Jointly developed (BNL, JLab, EIC Working Group)
• Addresses EIC accelerator physics, technology, and detector

issues

• Requires funding as recommended in NSAC 2007 LRP
• Scientific Case:
• Continue to develop and refine including defining critical

machine parameters

• ELIC: Expand and sharpen case for high luminosity
• 4th

EIC Workshop: jointly sponsored

• Continue EIC presentations -

eRHIC talk by B. Surrow

Page 45

Page 46

The 4th EIC Workshop

Monday, May 19 09:00 – 12:15 Accelerator Physics - Plenary Session I 13:30

• 17:30

Accelerator Physics – Parallel Sessions I and II Tuesday, May 20 09:00

• 12:15

Accelerator Physics – Plenary Session II 13:30

• 15:15

Accelerator Physics – Parallel Session III 15:45

• 17:30

Accelerator Physics – Plenary Session III 18:30

• 20:30

Workshop Reception @ Hampton Museum Wednesday, May 21 08:30 – 12:15 Plenary Session IV 13:30

• 18:00

Parallel Sessions IV and V (ep, eA, detector) 19:30 Collaboration Meeting Thursday, May 22 08:45

• 12:15

Plenary Session V 13:30

• 18:00

Parallel Sessions VI and VII (ep, eA, detector) 19:00 Workshop Dinner Friday, May 23 08:45

• 12:15

Plenary Session VI 13:30

• 16:30 Summary of (ep,eA, detector) Parallel Sessions and Closeout

ELIC BACKUP TRANSPARENCIES

ELIC R&D: Crab Crossing

• High repetition rate requires crab crossing to avoid parasitic beam-beam

interaction

• Crab cavities needed to restore head-on collision & avoid luminosity

reduction

• Minimizing crossing angle reduces crab cavity challenges & required R&D

State-of-art:

KEKB Squashed cell@TM110 Mode Crossing angle = 2 x 11 mrad Vkick=1.4 MV, Esp= 21 MV/m

Optimization

• IP configuration optimization
• “Lambertson”-type final focusing quad

angle reduction: 100 mrad 22 mrad

ELIC R&D: Crab Crossing (cont.)

magnetic Field in cold yoke around electron pass. Cross section of quad with beam passing through

10 cm 14cm 3cm 1.8m 20.8kG/cm 4.6cm 8.6cm

Electron (9GeV) Proton

(225GeV) 2.4cm 10cm 2.4cm 3cm 4.8cm

1st SC focusing quad for ion

Paul Brindza

Crab cavity development Electron: 1.2 MV – within state of art (KEK, single Cell, 1.8 MV) Ion: 24 MV (Integrated B field on axis 180G/4m) Crab Crossing R&D program – Understand gradient limit and packing factor – Multi-cell SRF crab cavity design capable for high current operation. – Phase and amplitude stability requirements – Beam dynamics study with crab crossing

ELIC R&D: Crab Crossing (cont.)

Detector R&D

• High-Speed Data Acquisition System

A high speed data acquisition and trigger system is required to allow for the very small bunch crossing times foreseen by the ELIC

• design. In particular, a trigger, readout electronics and data

acquisition systems need to be developed to pipeline data to handle 0.5 GHz (up to 1.5 GHz) RF frequency, to prove a >2,000 rejection

• f the hadronic

background at trigger level, to develop GHz ultrafast digitization capabilities and verify timing properties, to develop multi-processing data acquisition building on the recent developments for the CLAS detector described above, and simulate data rates in detectors and electronics. Also, "stability of intense ion beams" and "ion space charge" is the same issue.

Numerical Example at High Luminosity

At a luminosity of 1035 cm-2s-1, the total hadronic production rate is about 1 x 107 s-1 Assume a data-acquisition capability of 5,000 s-1

[CLAS @ Moment, at dead times of 15%, has achieved an event rate

• f up to 8,000 s-1, a data rate of 30+ MB/s, using pipeline TDCs,

dual-CPU ROCs, and multiprocessing in Event Builder]

Trigger would need to provide a factor of 2,000 rejection of hadronic events: seems challenging but near reality (CLAS12 assumes >2,000).

Bunch Spacing from Detector Point of View

CLAS operates at a 500 MHz bunch frequency. The e- can be traced back to the specific bunch, which is then used as “RF time tag” to calibrate the detectors for the hadrons.

Question: What are the implications in collider mode?

• 1. For the specific e-ion process, you still have the e-

tag

• 2. Collection times for (fast) detection devices is 10-20 ns

(e.g., silicon, scintillator, and PMT’s, but not for e.g. Ar calorimetry)

• 3. Ultrafast

digitization allows determinination

• f time less than the

resolving time of the specific detector (now, calibration becomes the main

issue, cf. CLAS)

• 4. The multiplicity w.r.t. CLAS increases by a factor of 4-5
• 5. Hence, can one untangle the interactions separated in time by

less than the resolving time of the detector in the face of pileup?

• 6. GHz digitizers with 8-bit accuracy already on the market

(250 MHz flash ADCs (10/12 bit) being developed at JLab)

Issue was/is also relevant for VLHC(<1.8 ns?), SLHC (12.5 ns?)

(pre-)R&D

General: all designs require Electron Cooling

$4M/year Accelerator R&D encompasses:

• Design Studies to Optimize Existing EIC Approaches
• High-Intensity Polarized Electron Source

(eRHIC L-R)

• Energy Recovery Technology for High Energy and High Current Beams

(eRHIC L-R)

• Development of Compact Recirculation Loop Magnets

(eRHIC L-R)

• Design and Prototype of Multi-Cell Crab Cavities

(ELIC) [required for L~1035 cm-2s-1]

• Simulations of Stacking Intense Ion Beams in Pre-Booster

(ELIC) [required for L~1035 cm-2s-1]

• Simulations of Electron Cooling w/circulator ring and GHz kicker prototype (ELIC)
• Precision High-Energy Ion Polarimetry
• Polarized 3He Production (EBIS) and Acceleration

$2M/year Detector R&D encompasses:

• Low-Angle Electron Tagging System
• Multi-Level Triggering System to Include Tracking and Reject Background
• High-Speed Data Acquisition System to Handle Small Bunch Spacing

( ELIC)

• Central Tracker Development
• cost-effective and compact high-rate tracking solution
• cost-effective method for hadron

identification

• tagging systems for recoiling neutrons and heavier nuclei

• A. Lung DIS2008 April 8, 2008

ELIC Recent Developments ELIC Recent Developments

ELIC design evolves

• in response to Science requirements (e.g. Rutgers mtg.)
• towards a more robust and reliable concept which relies increasingly on

proven state-of-the-art technology. Recent developments include:

• Higher center-of-mass energy and inclusion of heavy ions, up to Pb
• Concept of SRF ion linac

for all ions (ANL design)

• The use of stochastic cooling to accumulate intense ion beam
• Reducing crab cavity voltage requirement by decreasing crossing

angle from 100 mrad to 50 mrad and in combination with a new Lambertson-type final focus quadrupole

• Longer [±

3 m] element-free region around the IP’s

Thomas Jefferson National Accelerator Facility

• A. Lung, DIS2007 April 19, 2007

Advantages/Features of ELIC Advantages/Features of ELIC

JLab DC polarized electron gun already meets beam current requirements for filling the storage ring. A conventional kicker already in use in many storage rings would be sufficient. The 12 GeV CEBAF accelerator can serve as an injector to the ring. RF power upgrade might be required later depending on the performance

• f ring.

Physics experiments with polarized positron beam are possible. Possibilities for e+e-, e-e-, e+e+ colliding beams. No spin sensitivity to energy and optics. No orbit change with energy despite spin rotation. Collider operation appears compatible with simultaneous 12 GeV CEBAF operation for fixed target program.

• A. Lung DIS2008 April 8, 2008

World Data on F2

p

HERA F2

1 2 3 4 5 1 10 10 2 10 3 10 4 10 5

F2

em

• log10(x)

Q2(GeV2)

ZEUS NLO QCD fit H1 PDF 2000 fit H1 94-00 H1 (prel.) 99/00 ZEUS 96/97 BCDMS E665 NMC x=6.32E-5 x=0.000102 x=0.000161 x=0.000253 x=0.0004 x=0.0005 x=0.000632 x=0.0008 x=0.0013 x=0.0021 x=0.0032 x=0.005 x=0.008 x=0.013 x=0.021 x=0.032 x=0.05 x=0.08 x=0.13 x=0.18 x=0.25 x=0.4 x=0.65

World Data on g1

p

50% of momentum carried by gluons 20% of proton spin carried by quark spin

T h e d r e a m i s t

• p

r

• d

u c e a s i m i l a r p l

• t

f

• r

x Δ Δ g ( x ) v s x

• A. Lung DIS2008 April 8, 2008

The Quest for ΔG

First approach: use scaling violations

• f world g1

spin structure function measurements Not enough range in x and Q2

12 GeV BACK - UP

Page 60

High-level Parameters

Beam energy 12 GeV Beam power 1 MW Beam current (Hall D) 5 µA Emittance @ 12 GeV 10 nm-rad Energy spread @ 12 GeV 0.02% Simultaneous beam delivery Up to 3 halls

Kinematics for deeply exclusive experiments

unique kinematic range

GPDs via cross sections and asymmetries

EMC Effect - Theoretical Explanations

Quark picture

• Multi-quark cluster models

– Nucleus contains multinucleon clusters (e.g., 6-quark bag)

• Dynamical rescaling

– Confinement radius larger due to proximity to other nucleons

Hadron picture

• Nuclear binding

– Effects due to Fermi motion and nuclear binding energy, including virtual pion exchange

• Short range correlations

– High momentum components in nucleon wave function

• J. Ashman et al., Z. Phys.

C57, 211 (1993)

• J. Gomez et al., Phys. Rev.

D49, 4348 (1994)

x

D A

F F

2 2

• Observation that structure functions are altered in nuclei shocked much of the HEP

community 23 years ago

• ~1000 papers on the topic; models explain the curve by change of nucleon structure,

but more data are needed to uniquely identify the origin

What is it that alters the quark momentum in the nucleus?

Quark Structure of Nuclei:

JLab 12

Origin of the EMC Effect