Hall D Overview E.Chudakov JLab Presented at Workshop GlueX-PANDA 2019 George Washington University, 3-5 May 2019 E.Chudakov GlueX-PANDA 2019, GWU Hall D Overview 1 / 20
Outline JLab - Accelerator Facility 1 Accelerator and beam extraction Experimental halls Physics program Schedule Hall D 2 Layout and main parameters Planned upgrades Manpower E.Chudakov GlueX-PANDA 2019, GWU Hall D Overview 2 / 20
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Jefferson Lab E.Chudakov GlueX-PANDA 2019, GWU Hall D Overview 3 / 20
Jefferson Lab Staff: ∼ 700 ENP scientists: ∼ 60 Users: ∼ 1600 E.Chudakov GlueX-PANDA 2019, GWU Hall D Overview 3 / 20
CEBAF at 12 GeV D CHL • Accelerator: ≤ 2.2 GeV/pass • Accelerator: full current < 80 µ A • Halls A,B,C: e − 1-5 passes ≤ 11 GeV • Hall D: e − 5.5 passes ≤ 12 GeV A B C γ -beam • Beam extraction to 4 halls in parallel E.Chudakov GlueX-PANDA 2019, GWU Hall D Overview 4 / 20
CEBAF , adaptation 3 ⇒ 4 beams • Polarized electron beam (P>85%) • Four 249.5 (or 499) MHz interleaved beams, generating a 1497 MHz CW beam D GaAs crystal P e − ∼ 85 % • CW SRF linacs • • …5 RF Structure Beam current adjustment • • • Laser light: attenuation • Linacs: 1500 MHz • • Lasers: 500 MHz or 250 MHz • Electron beam: chopper slit E.Chudakov GlueX-PANDA 2019, GWU Hall D Overview 5 / 20
Chopper B Period: 2 ns C A Beam Beam Beam Beam Beam Beam Beam Beam Beam Beam Beam Beam Beam Beam Beam Beam Beam Beam Beam Beam Beam Beam Beam 4-Hall Operations Hall D shares a slit Chopper #1 Lens Master Slit Lens Chopper #2 • Slit size not flexible RF Cavity RF Cavity ⇒ limits the beam current (499 MHz) (499 MHz) • Sharing at 250 MHz E.Chudakov GlueX-PANDA 2019, GWU Hall D Overview 6 / 20
Beam circulation and extraction E.Chudakov GlueX-PANDA 2019, GWU Hall D Overview 7 / 20
Beam separation to 1 hall, passes 1-4 E.Chudakov GlueX-PANDA 2019, GWU Hall D Overview 8 / 20
Beam separation to 3 old halls, pass 5 E.Chudakov GlueX-PANDA 2019, GWU Hall D Overview 9 / 20
Beam separation to 4 halls, pass 5 Feature of the extraction: current leakage from other beams ∼ 0.5 nA E.Chudakov GlueX-PANDA 2019, GWU Hall D Overview 10 / 20
Accelerator Running Experience Runs Typically 2 runs per year (spring and fall) 2016 spring: first run at the full energy 12 GeV 2017 fall: 4 hall operations Hall D accumulated 330 calendar days with beam Accelerator Issues Breaks and long repairs (CHL, magnets, a transformer) Efficiency of beam delivery 50–70% due to linac trips, beam loss Gradual deterioration of the accelerator gradient ∼ 40 MeV/pass/Y: Energy for Hall D dropped to 11.2 GeV in spring 2019, expected to be 11.5 GeV in fall 2019 E.Chudakov GlueX-PANDA 2019, GWU Hall D Overview 11 / 20
CEBAF Performance Plan Target: 34 weeks/year operations at > 80% efficiency and 1090 MeV/linac Plan: refurbish the cavities - increase the energy reach, get more spares E.Chudakov GlueX-PANDA 2019, GWU Hall D Overview 12 / 20
JLab Experimental Halls Hall D Hall B Hall C Hall A forward calorimeter barrel time-of calorimeter -flight target on beam forward drift chambers central drift Diverse program Nucleon Structure chamber Nucleon Structure Spectroscopy Formfactors, PDF Valence quarks GPD, TMD Search for: SM tests (PV) exotic hybrid mesons Future installations large custom hermeticity high resolution acceptance installations e − 2.2–11 GeV 12 GeV e − ⇒ γ e − longitudinal polarization γ linear polariz. GlueX spectrometer CLAS12 HMS, SHMS HRS, SBS any, polar. 3 He � , ⊥ any, polar. 3 He � , ⊥ target LH LH, LD; ammon. � , ⊥ 10 38 cm − 2 s − 1 10 35 cm − 2 s − 1 <100 MHz/GeV σ ( p ) / p ∼ 1 − 3 % σ ( p ) / p ∼ 0 . 5 % σ ( p ) / p ∼ 0 . 1 % σ ( p ) / p ∼ 0 . 02 % E.Chudakov GlueX-PANDA 2019, GWU Hall D Overview 13 / 20
Approval and Scheduling of Experiments Program Advisory Committee (PAC) appointed by the Lab, 1 gives recommendations to the Lab’s management Meets yearly (typically in July) to consider the submitted proposals Verdicts: approved with rating / deferred / rejected Experiment preparations 2 Budget for new equipment: ENP or/and outside grants Readiness review (ENP) Scheduling Committee (Accelerator and Physics (ENP) Department 3 management) Assigns beam time E.Chudakov GlueX-PANDA 2019, GWU Hall D Overview 14 / 20
12 GeV Approved Experiments by Physics Topic Topic Hall A Hall B Hall C Hall D Other Total The Hadron spectra as probes of QCD 0 2 1 3 0 6 The transverse structure of the hadrons 6 3 3 1 0 13 The longitudinal structure of the hadrons 2 3 6 0 0 11 The 3D structure of the hadrons 5 9 6 0 0 20 Hadrons and cold nuclear matter 8 5 7 0 1 21 Low-energy tests of the Standard Model and 3 1 0 1 2 7 Fundamental Symmetries Total 24 23 23 5 3 78 Total Experiments Completed 4.6 2.7 2.1 1.0 0 10.4 Total Experiments Remaining 19.4 20.3 20.9 4.0 3.0 67.8 Remaining: ∼ 2500 PAC days left: about 10 years of running E.Chudakov GlueX-PANDA 2019, GWU Hall D Overview 15 / 20
Hall D Approved Experiments Proposal/ PAC Title PAC PAC experiment days # rating � E12-06-102 A 120 30 Mapping the Spectrum of Light Quark Mesons and Gluonic Excitations with Linearly Polarized Photons E12-10-011 A- A Precision Measurement of the eta Radia- 79 35 tive Decay Width via the Primakoff Effect E12-13-003 A 200 40 An initial study of hadron decays to strange final states with GlueX in Hall D E12-13-008 A- 25 40 Measuring the Charged Pion Polarizability in the γγ → π + π − Reaction E12-12-002 A A study of meson and baryon decays to 220 42 strange final states with GlueX in Hall D E12-12-002A A Grp 45 Eta Decays with Emphasis on Rare Neutral Modes: The JLab Eta Factory(JEF) Experi- ment E.Chudakov GlueX-PANDA 2019, GWU Hall D Overview 16 / 20
Program Advisory Committee PAC46 New Proposals Proposal/ Contact Title Days PAC PAC experiment person prop. rating decision PR12-18-001 A. Somov Photoproduction of vector 28 deferred mesons on nuclei with GlueX PR12-18-002 M. Amaryan Strange Hadron Spectroscopy 200 deferred with a Secondary K L Beam at GlueX Issues/Recommendations • PR12-18-001 improve the physics case, consider more topics • PR12-18-002 demonstrate a full analysis, a credible schedule etc. • Oral recommendation to the community from PAC and JLab : Produce a short “White Paper” expressing the intentions and interest in potential experiments beyond the approved ones ( Done! ). Jeopardy reminder Rule for Jeopardy: 4 years since (re)approval, not yet scheduled to finish ◮ 2020 PAC: Halls B/D: those not scheduled to finish in 2020 E.Chudakov GlueX-PANDA 2019, GWU Hall D Overview 17 / 20
Accelerator schedule till May 2020 May-December 2020: scheduled CHL-2K cold box installation E.Chudakov GlueX-PANDA 2019, GWU Hall D Overview 18 / 20
Hall D Project A part of 12 GeV Upgrade funded by the DOE Main motivation: experiment GlueX Construction: 2008-2014 by JLab and GlueX collaboration First beam for commissioning: December 2014 GlueX engineering run: spring 2016 GlueX-I data taking: spring 2017 - fall 2018 First PRIMEX- η run: spring 2019 Jan 2012 Tagger Hall Hall D E.Chudakov GlueX-PANDA 2019, GWU Hall D Overview 19 / 20
Photon beam and Hall D Facility • 12 GeV e − beam 0 . 001 − 5 µ A Diamond 20 µ m Collim. 3.4 mm • Coherent Bremsstrahlung • 3.4/5 mm collimator 8.4-9.0 GeV • In peak P ∼ 40 % < 100 MHz P ∼ 40 % tagged • Flux < 100 MHz in 7 - 12 GeV • Energy/polarization measured: collimated • Tagger spectrometer ∼ 0.2% • Polarimeter γ e − → e − e + e − σ P / P ∼ 2% E γ GeV E.Chudakov GlueX-PANDA 2019, GWU Hall D Overview 20 / 20
Hall D/GlueX Beam: Coherent Bremsstrahlung Tagger Scin. Hodoscopes Pair Spectrometer • TAGH: ∆ E ∼ 20 MeV • Range: 6-12 GeV • TAGM: ∆ E ∼ 5 MeV • Resolution: ∼ 1% Radiators Rate in Pair Spectrometer Photon Flux (Arb. Units) 7000 (a) Diamond: PARA • 20-50 µ m diamonds, 6000 Diamond: PERP Aluminum 5000 Aluminum 4000 • Alignment 3000 2000 1000 Polarization 7.5 8 8.5 9 9.5 10 10.5 11 11.5 P ≈ 40 % (b) 0.5 PARA 0.4 PERP 0.3 0.2 0.1 0 1.5% Syst. Uncert. 7.5 8 8.5 9 9.5 10 10.5 11 11.5 Photon Beam Energy (GeV) E.Chudakov GlueX-PANDA 2019, GWU Hall D Overview 21 / 20
Hall D/GlueX Beam: Coherent Bremsstrahlung Integrated Beam spectrum in 2016-2017 × 9 10 1000 Photon Flux / 20 MeV 900 800 700 600 500 400 300 200 100 0 8.5 9 9.5 10 10.5 11 11.5 12 E [GeV] γ E.Chudakov GlueX-PANDA 2019, GWU Hall D Overview 22 / 20
Hall D E.Chudakov GlueX-PANDA 2019, GWU Hall D Overview 23 / 20
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