Page 1Review 09/2010

MEIC R&D

Yuhong Zhang

Page 2Review 09/2010

Outline

• MEIC R&D Issues• View 1: EIC AC Recommendations• View 2: MEIC Design Status• View 3: Accelerator Technology Challenges

• Present Plan• CASA/JLab Internal Resources• External Collaborations• Research Proposals• Proposed Research Focuses

• Path Forward and Open Questions

Page 3Review 09/2010

EIC Advisory Committee Recommendations• Highest priority

• Design of JLab EIC• High current (e.g., 50 mA) polarized electron gun• Demonstration of high energy-high current recirculation ERL• Beam-beam simulations for EIC• Polarized 3He production and acceleration• Coherent electron cooling

• High priority, but could wait until decision made• Compact loop magnets• Electron cooling for JLab concepts• Traveling focusing scheme

(it is not clear what the loss in performance would be if it doesn’t work; it is not a show stopper if it doesn’t)

• Development of eRHIC-type SRF cavities

• Medium priority• Crab cavities• ERL technology development at JLab

Only for very low ion energy, 12 GeV or less

Most critical

Page 4Review 09/2010

MEIC Machine Design Status• Short term design goal (by next EIC AC meeting, 12/2010)

• We are committed to completing a MEIC design with sufficient technical details• Short term technical Strategy

• Limiting as many MEIC design parameters as we can within or close to the present state-of-art in order to minimize technical uncertainty and required R&D

• Mid-term design goal (by next NSAC Long Range Plan, ~2013)• A complete design supported with solid R&Ds & a zero-th order design report

• Unfinished design tasks (under the short term goal)

Electron complex• RF system• Polarization lifetime by spin tracking• Instability (feedback for multi-bunches)

Ion complex• Polarized and un-polarized ion sources• SRF Linac & pre-booster (cooling, tracking) • Design of big boosters• RF system in boosters and collider ring

• Ion polarization (scheme, tracking)• Electron cooling (cooler design, simulations)• Instabilities, electron cloud

Interaction region• IR design, magnet, background• Tracking studies and dynamics aperture • Crab crossing and cavities• Beam-beam simulations

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Accelerator Technology Challenges

Level of R&D

Low-to-Medium Energy(12x3 GeV/c) & (60x5 GeV/c)

High Energy(up to 250x10 GeV)

Challenging

Semi Challengin

g

Electron coolingTraveling focusing (for ion energies ~12 GeV)

Electron cooling

Likely IR design/chromaticityCrab crossing/crab cavityHigh intensity low energy ion beam

IR Design/chromaticityCrab crossing/crab cavityHigh intensity low energy ion beam

Know-how Spin trackingBeam-Beam

Spin trackingBeam-beam

• Interaction region design and limits with chromatic compensation

• Electron cooling• Crab crossing and crab cavity• Forming high intensity low energy ion beam• Beam-beam effect• Depolarization (including beam-beam) and spin tracking• Traveling focusing for very low energy ion beam

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Three Most Outstanding R&D Issues• Electron cooling of medium energy ions

• Effectiveness/efficiency of electron cooling at medium ion energy • Design of circulator cooler ring, development of fast kicker• High average beam current (ampere class) ERL• Dynamics of electron beam in a circulator ring & long term space charge effect• Dynamics of two coupled beams (cooling electrons and ions)

• Formation of high average current ion beams with high bunch repetition rate, small emittance and short bunch• Negative (H-, D-) ion sources and strip injections• Ion SRF linac• Low energy (~100 keV) long bunch (DC) electron cooling• Space charge effect in pre-booster

• Ion polarization in a Figure-8 ring• Demonstrate advantage of a Figure-8 ring for ion beams • Polarized deuteron beam

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JLab MEIC Accelerator Design Team• CASA (core team members)

• Alex Bogacz, Pavel Chevtsov (leaving), Slava Derbenev, Geoff Krafft, Rui Li, Vasiliy Morozov, Balsa Terzic, Byung Yunn, Yuhong Zhang

one graduate student (Hisham Sayed)• Approximately 4.35 FTE• Expertise: mostly theoretical/computational, some operational (on linac &

ERL)

linear optics, recirculated linac, ERL, instability, collective effects

polarization theory, electron cooling theory, beam-beam simulations

• New postdoc/staffs: up to 2 to 3 in the near future (pending grant applications)

• Within JLab• RF system: Frank Marhauser, Bob Rimmer, Haipeng Wang• Polarized electron source and photo-injector: Matt Poelker

• Expertise critically needed • Proton/ion beams, ion source and linac, storage ring, ring-ring collider• Situation changed significantly after arriving of two ion beam/collider experts:

Fulvia Filat and Todd Satogata

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External Collaborations

• IR/detector design M. Sullivan (SLAC)

• Ion sources V. Dudnikov, R. Johnson (Muons, Inc)

V. Danilov (ORNL)

• SRF Linac/Pre-booster S. Manikonda, P. Ostroumov* (ANL)

B. Erdelyi (NIU)

• Beam-beam simulation J. Qiang (LBNL) (supported by SciDAC)

• Electron cooling simulation D. Bruhwiler (Tech X) (supported by SciDAC)

• Polarization A. Kondratenko (Novosibirsk)

• Electron spin tracking D. Barber (DESY)

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Submitted Research ProposalProposal Title: Advanced Electron Ion Collider Design

Program: Research and Development for Next Generation Nuclear Physics Accelerator Facilities(DOE Financial Assistance Funding Opportunity Announcement LAB 10-339)

Amount request: $4.5M over 3 years

Status: Pending (initial feedback is positive)

Project 1. Collider Ring Design

2. Numerical Simulation of Beam-Beam and Other Beam Dynamics

3. Development of a Spin Manipulation and Stabilization System For a Future Electron-Ion Collider

4. Development of Advanced Electron Cooling Systems

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Present Research Focal PointsWe will concentrate R&D efforts on the most critical tasks

(proposed Feb. 2010)

Focal Point 1: Forming high-intensity short-bunch ion beams & coolingSub tasks: Complete design of the RF linac and pre-booster

Ion bunch dynamics and space charge effects (simulations) Led by Peter Ostroumov (ANL)

Focal Point 2: Electron cooling of medium-energy ion beam

Sub tasks: Electron cooling dynamics (simulations)

Complete design of the ERL-based circulator cooler

Dynamics of cooling electron bunch in an ERL circulator ring

Focal Point 3: Beam-beam interaction

Sub tasks: Include crab crossing and/or space charge

Include multiple bunches and interaction points

Including space charge effect for low ion energy

Page 11Review 09/2010

Path Forward and Strategy • Short term by next EIC AC Meeting ~12/2010

• Complete a conceptual design with sufficient technical details• Plug holes and fill design gaps• Conservative position on accelerator technology

design completeness over technology innovation & collider performance

• Intermediate term by next NSAC RLP ~2013• 1st Half

• Design optimization (still technology conservative)• Type I R&D: issues which will improve creditability of design and save cost

• 2nd Half• Design optimization (modest technology forward looking)• Type II R&D: issues which will improve collider performance and save cost

• Long term by ZDR/CDR ~2016• Design optimization, technology aggressive• Type III R&D: issues for maximum pay-off for best collider performance

Page 12Review 09/2010

Open Questions

• What are the most important R&D issues?

• Given present resources and expertise, how we prioritize these critical R&D topics?

• What are the reasonably achievable goals for• Short term R&D, by next EIC AC meeting, Feb. 2011• Intermediate term R&D, by next NSAC LRP, 2013

• What expertise we should add to the local design team?

• What new external collaborations we should seek to establish?