Hall C Research Program

Transcription

1 Hall C Research Program Have been running experiments since November PAC Days run, or 29.7 experiments (If 94 days lost in PAC jeopardy process are included ~ 70 PAC days/year) PAC Days in queue, or 13.6 experiments 27 days Conditionally Approved (CA), and 34 additional G0-Backward days included here. (almost all large-scale installation experiments) (Backlog: 4.8 Years) Almost 9 Large Installations to date: t 20, G En -98, HNSS, G En -00, G En -01, G0 (x2), HKS, G0-Backward 78 Ph.D. Subjects, 52 Ph.D. s awarded 44 refereed publications to date (20 PRL), 2 submitted (not including 7 NIM papers) 400+ users representing 20 different countries No collaboration, but steering committee to represent user community involved in diverse Hall C program dominated by largeinstallation experiments. Typical Hall C year (averaged over decade): 70 PAC days + 4 months installation

2 Steering Committee Hall C maintains experiment-specific collaborations, with 400+ users from 20 countries Hall C Steering Committee with as main tasks Provide effective channel of communication Represent the interests of Hall C users and Hall C Organize annual Hall C physics workshop 2003: John Arrington (ANL) Donal Day (UVa) Joerg Reinhold (FIU) Phil Roos (UMd) 2004: Betsy Beise (UMd) Donal Day (UVa) Joerg Reinhold (FIU) Wim Van Oers (Manitoba) 2005: Betsy Beise (UMd) Osamu Hashimoto (Tohoku) Allena Opper (Ohio) Wim Van Oers (Manitoba) 2006: Osamu Hashimoto (Tohoku) Roy Holt (ANL) Garth Huber (Regina) Allena Opper (GWU)

3 Hall C Approved Experiment Summary Base Equipment Experiments (2.6 experiments, 25 days): E Measurements of F 2 and R on Nuclear Targets 3 days (0.6) B+ E Measurement of Two-Photon Exchange in 13 days A- Unpolarized Elastic e-p Scattering E Measurement of R = σ L /σ T on Deuterium in the Nucleon 9 days A- Resonance Region and Beyond Large Installation Experiments beyond HKS (11 experiments, 308 days): E G0 Backward Angle Measurements 70 days A E Measurement of the PV Asymmetry for the N-Δ 0 days B+ E G0 Backward Angle Measurements (II) 34 days A E Measurement of G Ep /G Mp to Q 2 = 9 GeV 2 40 days A E Measurement of the Two-Photon Exchange Contribution 18 days A- in e-p Elastic Scattering Using Recoil Polar. E Spin Asymmetries on the Nucleon Experiment 27 days (CA) A- E Semi-Inclusive Spin Asymmetries on the Nucleon 25 days A- E Helicity Correlations in Wide-Angle Compton Scattering 14 days A- E The Qweak Experiment: A Search for Physics at the TeV 35 days A Scale via a Meas. of the Proton s Weak Charge E The Neutron Electric Form Factor at Q 2 = 4.3 GeV 2 from 25 days A- the D(e,e n) Reaction via Recoil Polarimetry E Spectroscopic Investigation of Hypernuclei in (II) 20 days A- Color coding indicates experiments using similar apparatus

4 Proton Spin Structure in the Resonance Region E01-006, Spokespersons: Oscar Rondon (UVa) + Mark Jones (Jlab) Dedicated experiment to measure both A 1 and A 2 at Q 2 = 1.3, for p and d. Here proton data only.

5 Proton Spin Structure in the Resonance Region E01-006, Spokespersons: Oscar Rondon (UVa) + Mark Jones (Jlab) Dedicated experiment to measure both g 1 and g 2 at Q 2 = 1.3, for p and d. Here proton data only. g 2 WW

6 Precise Measurement of Nuclear Dependence of Structure Functions in Light Nuclei E03-103, Spokespersons: John Arrington (ANL) + Dave Gaskell (Jlab) EMC effect ratios can be parameterized as ln(a)- or as ρ-dependence Solution: precisely measure 2 H, 3 He (new), and 4 He (improved). Add some solid targets for calibrations and improve upon the knowledge of large x region.

7 Precise Measurement of Nuclear Dependence of Structure Functions in Light Nuclei E03-103, Spokespersons: John Arrington (ANL) + Dave Gaskell (Jlab) Ph.D. Students: Aji Daniel (Houston) and Jason Seely (MIT) 12 C/ 2 H Ratio 4 He/ 2 H Ratio Uncertainties will still reduce (~factor of 2), but already clearly improved data quality at largest x values.

8 Measurement of Nuclear Transparency in A(e,e π) Reactions E01-107, Spokespersons: Dipangkar Dutta (Duke/TUNL) + Rolf Ent (Jlab) Analysis by Ben Clasie (MIT) Model dependency of ratios still +/- 10% No smoking gun for color transparency.

9 Hypernuclear spectroscopy (HKS/HES) program Last year: Enge + HKS run Status: Data on 1 H, 12 C : calibration 28 Si : production 7 Li, 9 Be, 51 V: tests >1000 counts in 12 Λ B g.s Final spectroscopy technique established (with tilt of Enge) preliminary spectra produced with resolution of 900 kev (σ) Believe resolution should be reduced to 600 kev (σ), but no spectra to show yet. HES design ongoing, new splitter design now checked by Accelerator Division (has large implications for beam dump line) HES magnets will be shipped to JLab end of 2007

10 Backward-Angle Installation Overview De-installation HKS beam dump line completed Backward-Angle Detectors installed Target installed and successfully test cool-down (LD2) SMS cool down complete, energized to 3000A Started backward-angle shielding, beam line installation Work dumped: more HKS de-installation + preparation for GEp-III (with the separation opportunity, Hall C lost 3 mechanical techs)

11 CED Installation Step 1: Clean Room to Hall C CED s were assembled in EEL clean room (Gary Rutledge, Stephanie Bailey, Michael Gericke, )

12 CED Installation Step 2: Attach jig and lift Lifting jig

13 CED Installation Step 3: Attach to FW Michael Gericke, Larry Lee, Des Ramsay + Hall C Techs + a lot of support from Survey and Alignment

14 Ad P ktt GEp-III Status (G Ep /G Mp up to Q 2 = 9 GeV 2 ) Large Calorimeter: Final stages of cosmics testing (Protvino, W&M,.) FPP: Chambers assembled, resolution & HV testing in final stage (Dubna, NSU) Add dedicated trigger scintillator plane (Tel Aviv) CH2 & Support frame on order, new gas handling system under construction Design of new scattering chamber ongoing: larger opening for BigCal, compatible with Hall A Collaboration work ready this Summer, Hall C work end of year? in GEANT3

15 Spin Asymmetries on the Nucleon Status Now three experiments with similar setup: E SANE (Rondon, Choi, Meziani): g 1 & g 2 at Q 2 = 4 GeV 2 E Semi-SANE (Bosted, Day, Jiang, Jones): Semi-Inclusive Spin Asymm. E WACS (Day, Wojtsekhowski): Helicity correlations in WACS Added: Quartz (NSU, JLab) Status: Plan to build Detector with user funds Gas Cherenkov Lucite Calorimeter (Temple) (NCAT,KSU,...) (Protvino, W&M, ) Frame Cherenkov under construction Quartz prototyping underway Lucite reference design Calorimeter ~ BigCal of GEp-III, augmented with gain monitoring (UVa) Scattering Chamber design near-final (encompasses all three experiments)

16 A Search for New Physics Beyond the Standard Model at the TeV Scale Coils (from France), coil holders (TRIUMF) all at MIT/Bates, support stand under construction (all move to MIT/Bates for assembly/testing) 9.5 ka power supply contract awarded (Synthetic) Quartz detectors coming in, PMTs are in. Electronics design complete: 18-bit ADC s + I-to-V s (LANL/TRIUMF), Preamplifiers: final production (TRIUMF) Irradiation test done: no long-term damage On track for Phase-I at end of 2008

17 A Search for New Physics Beyond the Standard Model at the TeV Scale Tracking Systems: Major Construction effort by university collaborators. LaTech Critical for : Checking optics and alignment Understanding backgrounds that leave tracks Determination of Q 2 Tracking detector status: Region I (small GEM): reading out half-size prototype VPI Region II (medium size pair of HDC s) single-plane prototype now understood, final design phase Region III (2.5 m long VDC) design complete, ordering frames and electronics W&M

18 Ongoing Hall C infrastructure work Electrical: 2MVA transformer in Hall (used for HKS) New DC Power Supply ordered (9.5kA, Qweak) Arc Flash calculations done New HMS Controls delayed but ready by Mechanical: A-can platform going in now (Acc.) 24 concrete shielding blocks made for G0, can be part of any shielding wall. New 4T crane (to drop shielding blocks outside radial crane radius)

19 12 GeV: SHMS design work (ANL/JLab) QD vs coaxial (Combined Function) Combine and lengthen quads Splitter instead of slider Name P m ax L fp FP t ilt Ω δρ δθ δφ δυ GeV meters deg m sr percent m r m r mm SQ-CF-SSA SQ-CF-MSA SQ-CF-LSA LQ-CF-SSA LQ-CF-MSA LQ-CF-LSA LQ-CF-SPLIT SQ-QD-SSA SQ-QD-MSA SQ-QD-LSA LQ-QD-SSA LQ-QD-MSA LQ-QD-LSA LQ-QD-SPLIT (Preliminary) Conclusion: longer quads + co-linear QD works, no slider easier

20 Summary: Good progress with analysis of 2003/4 experiments. Very lively user community with many Ph.D. students in pipeline. Excellent progress on SHMS optics design (special thanks to ANL!). Remaining program is essentially 6 large-installation experiments (or groups of experiments). User-provided equipment for these large installation experiments is on track and (far) ahead of Hall schedule. Most efficient/cost effective way to run Hall C is to adapt schedule such that changeovers are minimized make long-term schedule. The result is that the integration of new/different experiments in the future is nearly impossible. This seems o.k. as the backlog is likely as large as/larger than the time until the anticipated 12-GeV shutdown. Main worry of users with highly-rated experiments not directly compatible with 12 GeV is the looming conflict with 12-GeV down time due to reduced running times. Temporarily down in staff due to engineering redirect to 12-GeV at February 1 st but loss of technicians in February. Searches for one mechanical engineer and one deputy work coordinator will soon start. A temporary solution for technician staffing for FY06 is developed.