Fulvia Pilat VCU Workshop, October Overview of Jefferson Laboratory

Transcription

1 Fulvia Pilat VCU Workshop, October Overview of Jefferson Laboratory

2 Outline Introduction to Jefferson Lab 12 GeV Project & Commissioning SRF production and R&D Participation to LCLS-II Future of US nuclear physics: the Electron Ion Collider

3 Jefferson Lab Overview Core Competencies Nuclear Physics Research SRF Technology Polarized Electron Sources Cryogenics Research and Development FEL, accelerator physics

4 Jefferson Lab At-A-Glance Created to build and Operate the Continuous Electron Beam Accelerator Facility (CEBAF), worldunique user facility for Nuclear Physics: Mission is to gain a deeper understanding of the structure of matter and advance technology Established in 1986 by a collaboration of U.Va and W&M that gave birth to SURA In operation since ,261 Active Users 178 Completed Experiments to-date Produces ~1/3 of US PhDs in Nuclear Physics (478 PhDs granted to-date; 193 in progress) Managed for DOE by Jefferson Science Associates, LLC (JSA) Human Capital: 729 FTEs 22 Joint faculty; 20 Post docs; 6 Undergraduate, 34 Graduate students K-12 Science Education program serves as national model Site is 169 Acres, and includes: 81 Buildings & Trailers; 890K SF Replacement Plant Value: $389M FY 2013: Total Lab Operating Costs: $169M Non-DOE Costs: $9M

5 Outline Intro to JLAB 12 GeV Project & Commissioning Participation to LCLS-II Future of US nuclear physics: the Electron Ion Collider

6 Scope of the 12 GeV Upgrade Add 5 high performance cryomdules in each linac and their associated LLRF Systems Double the capacity of the Central Helium Liquefier Upgrade magnets and power supplies for recirculation arcs Upgrade Extraction, Instrumentation and Diagnostics, and Safety Systems Add new beamlines for Arc 10 and Hall D Add new experimental Hall D and upgrade existing Halls

7 12 GeV Upgrade Project Highlights 12 GeV Upgrade progress on many fronts Accelerator 100% complete: cryomods, cryogenics, beam transport done Hall B 73% complete: PCAL/FTOF installed ; Torus coil winding Hall D 97% complete: on track for beam commissioning Fall 2014 Hall C 73% complete: shield house installed ; Dipole coil winding

8 Commissioning Milestones Three main goals for the November 2013 May 2014 run period: Deliver 2.2 GeV Beam to the 2R dump. Deliver greater than 6 GeV beam to Hall A and run first CW beam of the 12 GeV era to an experimental Hall. Deliver greater than 10 GeV in 5.5 passes to Hall D.

9 Timeline of Commissioning Progress

10 Commissioning Milestones 2.2 GeV Beam on ARC 2 Viewer First data from Scattered Electrons in Hall A 10.5 GeV Beam to Hall D Ramp 8 Hour Availability for 2.2 GeV Run Six Beams in the NL for the First Time 10.5 GeV Beam to Hall D Tagger Dump

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12 Outline Intro to JLAB 12 GeV Project & Commissioning SRF production and R&D Participation to LCLS-II Future of US nuclear physics: the Electron Ion Collider

13 SRF R&D

14 R&D areas CEBAF LCLS-II CLS (4K) Efficiency (High Q 0 ) ILC XFELs υ Factory Energy µ Collider (High E acc ) FCC e.g. ISOTOPES C therapy UV FELs EIC/FCC FELs PIPII ESS ADS Intensity (High I b )

15 SRF infrastructure

16 Ingot/Large Grain/Single Crystal Cavities Ingot with large central grain 19 disk made by 650 MHz Project X enlarging smaller slice ANL crab cavity Formed cup HZDR gun cavity LG Upgrade cavities W. + X.Singer Single Crystal Cavit ILC 9-cell cavities LG Ichiro 9-cells 2.45 GHz magnetron

17 Doe Site Visit July 9, Ingot and Low RRR Niobium Three 650 MHz single cell cavities have been fabricated from enlarged high RRR material (1) and reactor grade Nb ( 2) Three CEBAF type single cell cavities were also fabricated: one large grain with RRR~140; one fine grain from RG niobium, one stitched RG. All reached mt (~20 25 MV/m) Candidates for further process development Preliminary FE limited Three 650 MHz test cavities 19 disk made by enlarging smaller slice First test of 650 MHz cavity made from enlarged ingot slice

18 JLab high-current cavities Ideal for ADS! Two 1.5 GHz, one 750 MHz prototypes built and tested Results exceed requirements High power RF window demonstrated to > 60 kw CW 1.5 GHz ERL cavities 1.5 GHz ERL cavity Shape optimization for BBU/HOM power HOM load concept 1.5 GHz window Module concept 750 MHz ERL cavity BBU simulations for 1.5 GHz ERL

19 Double spoke cavity Ideal for ADS! Key is to maximize G*Ra/Q to minimize dynamic heat load Thesis of Feisi He, PKU JLAB 352 MHz Cavity Design Spoke Elliptical Frequency [MHz] Aperture diameter[mm] Lcavity (end-to-end) [mm] Cavity inner diameter [mm] Cavity weight (3mm wall) [kg] Ep/Ea 4.3 ± ± 0.1 Bp/Ea [mt/(mv/m)] 7.6 ± ± 0.1 Geometry factor [Ω] Ra/Q [Ω] Ra*Rs (=G*Ra/Q) [Ω 2 ] 1.40 x x 10 5 At Vacc = 8.5 MV and 4.5K. So Rbcs=48nΩ, and assume Rres=20nΩ Ep [MV/m] 28.6 ± ± 0.5 Bp [mt] 50.3 ± ± 0.7 Max heat flux [mw/cm^2] Q x x 10 9 Power loss [W] Leff=1.5*β 0 *λ [m]

20 A New LCLS-II Project Redesigned in Response to BESAC Accelerator Undulators in existing LCLS-I Tunnel Superconducting linac: 4 GeV New variable gap (north) New variable gap (south), replaces existing fixed-gap und. Instruments Total Project Cost $895M Re-purpose existing instruments (instrument and detector upgrades needed to fully exploit) 4 GeV SC Linac In sectors GeV LCLS linac still used for x-rays up to 25 kev North side source: kev ( 100kHz) NEH FEH South side source: kev (120 Hz, copper linac ) kev ( 100 khz, SC Linac) LCLS-II Director s Review, August 19-21,

21 Project Collaboration 50% of cryomodules: 1.3 GHz Cryomodules: 3.9 GHz Cryomodule engineering/design Helium distribution Processing for high Q (FNAL-invented gas doping) 50% of cryomodules: 1.3 GHz Cryoplant selection/design Processing for high Q Undulators e - gun & associated injector systems Undulator Vacuum Chamber Also supports FNAL w/ SCRF cleaning facility Undulator R&D: vertical polarization R&D planning, prototype support processing for high-q (high Q gas doping) e - gun option LCLS-II Director s Review, August 19-21,

22 LCLS-II Linac Thirty-five 1.3 GHz 8-cavity cryomodules Two 3.9 GHz 8-cavity cryomodules Four cold segments (L0, L1, L2 and L3) which are separated by warm beamline sections. 2 2

23 Cryo Current Full Plant Design Single 2K Cryogenic Plant ~110 kpa ~1.54 kpa CC5 CC4 CC3 CC2 CC1 2.0 K Cold Box 4.5 K Cold Box Liquid Helium Temperature Capacity 2 K 4.0 kw 5K to 8K 1.2 kw 40K to 80K 13.4 kw Cryo Distribution Cryomodules Typical 2K System JLab CHL-2 does not have an intermediate-temperature cryogen intercept circuit 2 3

24 Outline Intro to JLAB 12 GeV Project & Commissioning Participation to LCLS-II Future of US nuclear physics: the Electron Ion Collider

25 Luminosity cm. -2 sec E E E E E E E E E+30 EIC HERA (no p pol.) COMPASS EMC JLab 12 HERMES x The Reach of EIC High Luminosity cm -2 s -1 Low x regime x High Polarization 70% Discovery Potential!

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27 MEIC Design Report Released Table of Contents Executive Summary 1. Introduction 2. Nuclear Physics with MEIC 3. Baseline Design and Luminosity Concept 4. Electron Complex 5. Ion Complex 6. Electron Cooling 7. Interaction Regions 8. Outlook arxiv:

28 MEIC Design Goals Energy Full coverage of s from 15 to 70 GeV Electrons 3-12 GeV, protons GeV, ions GeV/u Ion species Polarized light ions: p, d, 3 He, and possibly Li Un-polarized light to heavy ions up to A above 200 (Au, Pb) At least 2 detectors Full acceptance is critical for the primary detector Luminosity Above cm -2 s -1 per IP in a broad CM energy range Maximum luminosity >10 34 optimized to be around s=45 GeV Polarization At IP: longitudinal for both beams, transverse for ions only All polarizations >70% Upgrade to higher energies and luminosity possible 20 GeV electron, 250 GeV proton, and 100 GeV/u ion Design goals consistent with the White Paper requirements 28

29 MEIC Layout Pre-booster Linac Ion Sourc e MEIC collider rings IP IP Full Energy EIC Collider rings 11 GeV 12 GeV CEBAF 12 GeV Warm large booster (3 to 25 GeV/c) Three compact rings: 3 to 12 GeV electron Up to 25 GeV/c proton (warm) Up to 100 GeV/c proton (cold) Three Figure-8 rings stacked vertically Ion source SRF linac Pre-booster Warm electron collider ring (3-12 GeV) Medium-energy IPs with horizontal beam crossing Cold ion collider ring ( GeV) Injector 12 GeV CEBAF 29

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31 Design Strategy for: High Luminosity The MEIC design concept for high luminosity is based on high bunch repetition rate CW colliding beams Beam Design High repetition rate Low bunch charge Short bunch length Small emittance IR Design Small β* Crab crossing Damping Synchrotron radiation Electron cooling KEK-B already reached above 2x10 34 /cm 2 /s n n n n 4π σ ε β L = f ~ f * * * x y y Traditional hadrons colliders Small number of bunches Small collision frequency f Large bunch charge n 1 and n 2 Long bunch length Large beta-star Linac-Ring colliders Large beam-beam parameter for the electron beam Need to maintain high polarized electron current High energy/current ERL 31

32 Design strategy for High Polarization All rings have a figure-8 shape with critical advantages for both ion and electron beam Spin precessions in the left & right parts of the ring are exactly cancelled Net spin precession (spin tune) is zero, thus energy independent Spin is easily controlled and stabilized by small solenoids or other compact spin rotators Advantage 1: Ion spin preservation during acceleration Ensures spin preservation Avoids energy-dependent spin sensitivity for all species of ions Allows a high polarization for all light ion beams Advantage 2: Ease of spin manipulation Delivering desired polarization at multiple collision points Advantage 3: The only practical way to accommodate polarized deuterons (ultra small g-2) Advantage 4: Strong reduction of quantum depolarization thanks to the energy independent spin tune This helps to preserve polarization of the electron beam continuously injected from CEBAF 32

33 Nominal Design Parameters Detector Full Acceptance Large Acceptance Proton Electron Proton Electron Beam energy GeV Collision frequency MHz Particles per bunch Beam Current A Polarization > 70% ~ 80% > 70% ~ 80% Energy spread 10-4 ~ ~ RMS bunch length cm Horizontal emittance, normalized µm rad Vertical emittance, normalized µm rad Horizontal and vertical β* cm 10 and 2 10 and 2 4 and and 0.8 Vertical beam-beam tune shift Laslett tune shift 0.06 Very small 0.06 Very small Distance from IP to 1 st FF quad m 7 (down) 3.5 (up) (down) 3.5 (up) Luminosity per IP, cm -2 s

34 MEIC/EIC e-a luminosity MEIC EIC 34

35 MEIC systems Ion injector Ion pre-booster Ion large booster Overview of MEIC design and R&D Conventional technology, detailed simulations needed should not present an issue Ion collider ring Optimization of non-linear dynamics correction started Electron collider ring Encouraging initial simulation results New collaborations on Correction and DA Interaction regions initiated Polarization Preliminary spin tracking of figure 8 OK Cooling Circulator design Transfer lines, synchronization Critical MEIC R&D High current ERL and circulator High charge/current magnetized e-source Ultra fast kicker Crab cavity E ring RF system Status Conceptual design, e-cooling simulations done 2 options (thermionic gun or RF photo-cathode gun) RF harmonic kicker concept (JLAB LDRD) New cavity design developed at ODU R&D in progress at JLAB SRF 35

36 Multi-Staged e-cooling Scheme pre-booster (3 GeV) (accumulation) large booster (25 GeV) medium energy collider ring ion sources SRF Linac DC cooling High Energy cooling Pre-booster Collider ring Stage Ion (GeV/u) Electron (MeV) Assisting accumulation of positive ions Initial cooling to reduce emittance Initial cooling for emittance reduction Final cooling for emittance reduction During collision (suppress IBS) 0.1 (injection) long bunches 3 (extraction) long bunches 25 (injection) long bunches Up to 100 bunched beam Up to 100 bunched beam, 1 cm Cooling beam /Cooler state-of-the-art 0.59 DC 2.1 DC Bunched /ERL Bunched /ERL Bunched /ERL 36

37 Luminosity at different cooling stages Luminosity ( /cm 2 /s) Luminosity Low energy DC cooling only at prebooster injection ~0.41 Add weak electron cooling & stochastic cooling (heavy ions) during collision ~1.1 Based on existing technologies ~3.3 Add 3 GeV DC cooling at prebooster 5.6 Full capacity electron cooling (ERL-circulator cooler)

38 MEIC present goals Support the LRP process (12-18 months) Optimize design for cost, performance and potential for upgrades Produce a cost estimate by end of CY2014 Plan towards a MEIC Design Report and deliverables for down-select (~ 3 years) Collaborate with/respond to Physics Division on MEIC Collaborate with BNL and MIT on generic EIC R&D

39 EIC Realization Imagined Activity Name GeV Upgrade FRIB EIC Physics Case NSAC LRP EIC CD0 EIC Machine Design/R&D EIC CD1/Downsel EIC CD2/CD3 EIC Construction Assumes endorsement for an EIC at the next NSAC Long Range Assumes relevant accelerator R&D for down-select process done

40 Conclusions and outlook JLAB is commissioning and preparing to deliver 12 GeV physics We leveraged lab core competencies (SRF cryomodule production, cryogenics) towards LCLS-II We are proposing a novel design to realize the Electron-Ion collider for the future of nuclear physics We are welcoming and fostering collaboration with national and international institutions 40