MEIC/ELIC Meeting 03/23/2012

1. MEIC/ELIC Meeting 03/23/2012 • Updates • JLab User Town Meeting • Accelerator R&D Call for Proposals - Cooling • JLab Science & Technology Review • Ongoing work: design, cost estimate • More? • JLab user proposals for generic detector R&D call • Update on MEIC detector and interaction region • Update on science impact plots/discussion

2. Users Town Meeting Friday March 16, 2012 Agenda

3. Workshop to discuss science drivers of such an idea organized by GWU at Ashburn, VA Physics with Secondary Hadron Beams in the 21st Century (April 7th 2012)

4. Draft text Strategic Plan Physics In the longer-term vision, an Electron-Ion Collider is the ultimate tool to study the role of sea quarks and gluons to nucleon structure. Over the previous two decades, it was found that both sea quarks and gluons play an unexpected prominent role in nucleon structure, with 99% of the proton’s mass due to the self-generating gluon field and the proton sea having a non-trivial structure. The nucleon appears to be far more than its simple three-quark valence structure studied with the 12-GeV Upgrade. A collider environment provides, beyond its energy reach, tremendous advantages in terms of for instance polarization flexibility and purity, and access to spectator quarks, as compared to fixed-target facilities. The Electron-Ion Collider would be the world’s first polarized electron-proton collider and the world’s first e-A collider, and shed light on the dynamical basis of the structure of hadrons and nuclei in terms of the fundamental quarks and gluons of QCD. In particular, the main science themes of an Electron-Ion Collider are to i) map the spin and spatial structure of quarks and gluons in nucleons; ii) discover the collective effects of gluons in atomic nuclei; and iii) understand the emergence of hadronic matter from color charge. In addition, there are opportunities for fundamental symmetry measurements using the electroweak probe. JLab has concentrated on a competitive Electron-Ion Collider design with fully integrated detector and interaction region, maximized acceptance, and achievable technical parameters. The ion accelerator complex and pre-booster could also provide a facility for secondary hadron beams, either to complement nucleon structure studies or to fulfill the industrial request for accuracy of fission cross sections in the energy range up to 20 MeV.

6. ERL Based Circulator Electron Cooler solenoid 20 m • Design Choice • to meet design challenges • RF power (up to 50 MW) • Cathode lifetime (130 kC/day) • Required technology • High bunch charge gun ERL (50 MeV, 15 mA) (Ultra) fast kicker/RF separator Solenoid (15 m) ion bunch F injector v≈c electron bunch surface charge density h D SRF kicking beam Cooling section σc v0 L energy recovery Fast kicker circulator ring Fast kicker dumper Electron bunches circulate 10-100 times, leads to a factor of 10-100 reduction of the current from a photo-injector/ERL Cooling at the center of Figure-8 Beam-beam fast kicker dump injector SRF Linac Vladimir Shiltsev • Eliminating a long return path could • cut cooling time by half, or • reduce the cooling electron current by half, or • reduce the number of circulations by half

7. Proposal of MEIC e-Cooler Test Facility 20 m Solenoid (15 m) Baseline Design Concept • Energy recovery linac (for solving high RF power problem) • Circulator ring (for solving short e-source life-time problem) injector SRF 75 MHz ERL, tossing 1/10 bunches to reduce beam-beam interaction seems moderate risk for source and beam transfer Idea: use JLab FEL as test facility • Cover the right energy range, need to add a circulator ring • Much major hardware (e-source, ERL, magnets) exists  cost-effective • JLab FEL team helped to develop concept Dechirper Rechirper dumper

8. Developing a Cost Estimate • Internal cost estimate is conducted by two external consultants and JLab engineers, supported by the MEIC accelerator design teams • Two-step process • Step 1: the consultants provide an itemized cost estimate, and also identify top three cost drivers • Ion linac (SRF modules) • Refrigeration system • SC magnets and SRF cooling in the ring • Step 2: JLab engineers perform a detailed cost studies on the top three cost drivers • This will allow us to develop a cost estimate where the cost drivers are accurately known and the error bar on the rest can be reasonably estimated • Expected completion date for internal evaluation: end of Feb. 12

9. Generic Detector R&D for an EIC • Approved Detector R&D items after 1st call/meeting • (see also https://wiki.bnl.gov/conferences/index.php/EIC_R%25D) • DIRC-based PID for the EIC Central Detector • Catholic U A, Old Dominion U, GSI/Darmstadt, JLab • 2) Proposal to test improved radiation tolerant Silicon PMTs • JLab Radiation Detector & Imaging (RDI) Group • Letter-of-Intent for detector R&D towards an EIC detector • BNL-based collaboration, includes UVa (+Temple for 2nd call) • Submitted in response to 2nd call for proposals • DIRC-based PID for the EIC Central Detector • Includes SiPMT, augmented with USC & JLab RDI Group • 2) Micro-Pattern Gaseous Detectors for a Vertex Tracker in EIC Saclay, MIT, Temple • 3) Development of a Spin-Light Polarimeter for the EIC • Mississippi State U, ANL, Mainz, Stony Brook U, UVa, W&M • First two approved, third was well received but got homework assignment to “further develop this very interesting proposal”

10. Generic Detector R&D for an EIC • (see https://wiki.bnl.gov/conferences/index.php/EIC_R%25D) • Approved and to be submitted in response to 3rd call for proposals • DIRC-based PID for the EIC Central Detector • Includes SiPMT, CUA, ODU, GSI/Darmstadt, USC & JLab • Micro-Pattern Gaseous Detectors for a Vertex Tracker in EIC • Saclay, MIT, Temple • (requested to return with proposal(s)) • Letter-of-Intent for detector R&D towards an EIC detector • BNL-based collaboration, includes UVa (+Temple for 2nd call) • (resubmitted) • 4) Development of a Spin-Light Polarimeter for the EIC • Mississippi State U, ANL, Mainz, Stony Brook U, UVa, W&M • (to be submitted) • RICH-based PID for EIC • INFN, JLab, … • (maybe?) • 6) Incorporate tracking info in pipelined trigger electronics/DAQ • JLab Fast Electronics Group

11. MEIC Detector & Interaction Region • GEANT4 model of extended IR exists • Optimized integrated detector/IR • detect down to 0.005 dp/p with zero angle • detect down to 2 mr angle at any dp/p • other combinations possible • resolutions consistent with exp. needs • Truly fully integrated detector/IR with • FULL acceptance detector All achievable magnets! n p e

12. Acceptance of Downstream Electron Final Focus • 5 GeV/c e-, uniform spreads: -0.5/0in p/pand25 mradin horizontal/vertical angle • Apertures: Quads = 6, 6, 3 T / (By /x @ 11 GeV/c), Dipoles = 2020 cm ion beam  |p/p| > 0.01 @ x,y = 0 |x| > 0.4-4 mrad @ p/p = 0

13. Image the Transverse Momentum of the Quarks Prokudin, Qian, Huang Only a small subset of the (x,Q2) landscape has been mapped here: terra incognita Gray band: present “knowledge” Red band: EIC (1s) (dark gray band: EIC (2s)) Prokudin Exact kT distribution unknown! “Knowledge” of kT distribution at large kT is artificial! (but also perturbative calculable limit at large kT) An EIC with good luminosity & high transverse polarization is the optimal tool to to study this!

14. F2p & F2d @ high x still needed from EIC • Similar improvement in F2p at large x • F2n tagging measurements relatively straightforward in EIC designs • EIC will have excellent kinematics to further measure/constrain n/p at large x! F2 Similar reduction with neural networks (Rojo + Accardi) Q2 (GeV2) • s = 1000 • One year of running (26 weeks) at 50% efficiency, or 35 fb-1 Sensible reduction in PDF error, likely larger reduction if also energy scan