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Hall C Opportunities at 12 GeV

Hall C Opportunities at 12 GeV. Dave Mack (TJNAF) for Steve Wood, Hall C Group Leader Workshop on Hadronic Physics in China and Opportunities with 12 GeV Jlab August 1, 2009 Lanzhou, China.

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Hall C Opportunities at 12 GeV

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  1. Hall C Opportunities at 12 GeV Dave Mack (TJNAF) for Steve Wood, Hall C Group Leader Workshop on Hadronic Physics in China and Opportunities with 12 GeVJlab August 1, 2009 Lanzhou, China

  2. The well understood interactions of point-like electrons, and the high intensity and quality of modern electron beams, make them ideal for studying the charge and magnetization distributions in nuclear matter. Interactions of Electrons Because of the different isospin coupling of the γ and Z0, parity violating electron scattering provides an additional window on flavor. In precision measurements of Standard Model-suppressed observables, the large mass of the Z0 even brings potential new physics at TeV-scales within reach. Hall C at 12 GeV

  3. Jefferson Laboratory is a multi-GeVelectron accelerator located in Newport News, Virginia, USA. Where is Jlab? Exploiting the intensity and precision frontiers, with state of the art spectrometers and targets, has made JLab an incredibly productive facility. Hall C at 12 GeV

  4. Hall C’s 4-6 GeV Base Equipment Since 1995, Hall C has carried out a program of inclusive (e,e’) and coincidence (e,e’h) measurements with the SOS and HMS as base equipment. While the resistive SOS became increasingly obsolete due to increasing beam energy, a rich HMS program with new, user-supplied detectors and targets continued. High Momentum Spectrometer Pmax = 7.5 GeV/c world’s highest energy, movable focusing magnetic spectrometer Short Orbit Spectrometer Pmax = 1.7 GeV/c e- beam Hall C at 12 GeV

  5. BYOD Program (Bring Your Own Detector) Our hypernuclear and parity programs require such specialized apparatus that that often do not use the base equipment. G0 spectrometer for s-quark form factors Hall C at 12 GeV

  6. Pion and nucleon elastic form factors at high momentum transfer Deep inelastic scattering at high Bjorken x Semi-inclusive scattering at high hadron momenta Polarized and unpolarized scattering on nuclei Motivations for Hall C Upgrade • The HMS will remain important in the 12 GeV program, especially for electron detection. What is needed is a new spectrometer better suited for detecting charged hadrons at very high energies: • Higher momentum capability (11 GeV/c) • Smaller angle capability (5.5 degrees) • Very good particle identification (e, π, k, p) • Accurate and reproducible angle and momentum settings • The SHMS (Super High Momentum Spectrometer) meets these requirements. Hall C at 12 GeV

  7. Hall C with SHMS (11 GeV/c) SHMS: dQQQD HMS: QQQD SOS (removed) Hall C at 12 GeV

  8. SHMS Small Angle Challenge Q2 Horizontal bender SHMS 5.50 HB Q1’ target chamber HMS 10.50

  9. Bender Fit to HMS Q1 SHMS Bender HMS Q1 Hall C at 12 GeV

  10. Shield House Fit to Beamline Shield House Dipole Beamline Q3 Q2 Q1 Shield House notch Bender Hall C at 12 GeV

  11. Giant Scissors? Mating Dinosaurs? Top View Bottom View SHMS SHMS … or just an incredible 3-dimensional jigsaw puzzle for our engineers and designers. Hall C at 12 GeV

  12. SHMS All Dressed Up • Key Features: • 3 quadrupole magnets, • 1 dipole magnet • Provides easily calibrated • optics and wide acceptance • Uses magnets very similar • to existing ones • 1 horizontal bend magnet • Allows forward • acceptance • New design, • developed in • collaboration • w/MSU • 6 element detector package • Drift Chambers / Hodoscopes / Cerenkovs / Calorimeter • All derived from existing HMS/SOS detector designs • Rigid Support Structure / Well-Shielded Detector Enclosure • Reproduces Pointing Accuracy & Reproducibility demonstrated in HMS Hall C at 12 GeV

  13. Particle ID: Limitations of TOF • TOF over the short ~2.2m baseline inside the SHMS hut will be of little use for most of the momentum range anticipated for the SHMS. • Even over a 22.5m distance from the target to the SHMS detector stack, TOF is of limited use. Effect of finite timing resolution (±1.5σ with σ=200ps). Separation <3σ to the right of where lines intersect.

  14. SHMS Particle Identification: +hadrons TOF Heavy Gas Cerenkov Aerogels Rejection Power known experiments Momentum (GeV/c) Hall C at 12 GeV

  15. SHMS Detectors Trigger hodoscopes (James Madison University and North Carolina A&T) Lead Glass Calorimeter Yerevan/JLab Heavy gas Cerenkov (University of Regina) Drift chambers (Hampton University) Noble gas Cerenkov (University of Virginia) Hall C at 12 GeV

  16. Approved 12-GeV Experiment Example of an electron-hadron coincidence experiment • Continuation of successful Fπ • program to dramatically higher Q2 • Requires: • small forward angle capability • Kinematic control for L/T separation • resolution to distinguish p(e,e’π+)n events from • p(e,e’π+)n+π Hall C at 12 GeV

  17. Approved 12-GeV Experiment Example of an inclusive electron experiment HMS • Focused on mapping out the distributions of superfast quarks and high momentum nucleons …connected to the short distance structure of nuclei. • Requires: • high momentum • good PID SHMS The black symbols indicated the range with a 6 GeV from E02-019, the red reflect that obtained in the CLAS ratio measurements. The blue symbols and line define the region accessible at 11 GeV. The solid (dashed) blue curve indicates the region where the pro jected statistical uncertainties are 10% (5%) for an x bin of 0.05. Hall C at 12 GeV

  18. Hall C Upgrade Costs By Subsystem… As part of the entire 12GeV upgrade… Does not include NSF contribution to detectors

  19. Proposing Experiments at 12 GeV Hall C Jlab is an open laboratory. By this I mean that, if you have a great idea for one of our end-stations, you can propose it to our Program Advisory Committee (PAC) of mostly outside experts. Your proposal will be judged on the merit of the physics as well as the technical feasibility. An internal co-spokesperson may be helpful but is not required. A tremendous amount of information can be gain from our website at http://www.jlab.org/ and looking under topics such as “Nuclear Physics”, “Experiment Research”, and “12 GeV Upgrade”. Proposals now mostly fall into two categories: standard 12 GeV equipment, or major new detectors. Proponents are expected to help build or commission new apparatus. Of course, funding, manpower (both collaboration and Jlab), and multi-endstation scheduling issues will eventually be looked at carefully. Hall C at 12 GeV

  20. Some Contact Persons The easiest way to get involved is to join an existing collaboration on an experiment you find interesting. With a nominal “beam on” date of October 1, 2014, most Hall C 12 GeV collaborations are still forming and are eager for new people. Hall C at 12 GeV

  21. Summary I’ve tried to introduce some of the standard apparatus for Hall C at 12 GeV. More detailed information on the SHMS can be obtained at http://www.jlab.org/Hall-C/upgrade/index.html Hall C at 12 GeV

  22. Acknowledgements Hall C colleagues Howard Fenker and Paul Brindza whose slides formed the basis of my talk. The organizers of this workshop for their invitation and the countless headaches they must have undergone. The workshop support staff for making it all work. Hall C at 12 GeV

  23. Extras Hall C at 12 GeV

  24. Hall-C 12-GeV Experiments Hall C at 12 GeV

  25. SHMS PID Requirements : negative polarity • PID requirements at negative polarity are dominated by the x>1 experiment Hall C at 12 GeV

  26. SHMS Experiment Resolution Requirements * Not yet submitted to PAC Δp/p (%) Δφ (radians) Δθ (radians) 2x Spec’d Resolution & MCS Spec’d Resolution & MCS Spec’d Resolution +22% -10% Hall C at 12 GeV

  27. SHMS Elements Dipole 18.4 Degree Bend Max Field: 4.76 T EFL: 2.85 m Bender 3 Degree Bend Max Field: 3.11 T EFL: 0.75 m Q2 Q3 Max Gradient: 14.4 T/m EFL: 1.61 m Q1 Max Gradient: 10.63 T/m EFL: 1.86m Hall C at 12 GeV

  28. The SHMS Detector System Noble Gas Cerenkov: e/π (or π /K) separation at high momenta University of Virginia • 2.5 m long gas radiator at atmospheric pressure • Argon: π threshold ~ 6 GeV/c • Adding Neon: threshold may be varied up to 12 GeV/c • Para-Terphynyl PMT window over-coating • Performance 20 photoelectrons • (worst case: pure Neon) • At low momenta: remove mirrors, • insert coupling so that the tank • becomes part of the vacuum • system – reduces MCS Hall C at 12 GeV

  29. The SHMS Detector System Noble Gas Cerenkov Reference Design (HMS Cerenkov) 4 spherical mirrors, 45cm x 45 cm Ray-trace simulation of optics. Hall C at 12 GeV

  30. The SHMS Detector System Trigger Hodoscopes Mechanical Design is a re-scaling of existing HMS/SOS design 0.5cm paddle overlap – all paddles Hall C at 12 GeV

  31. The SHMS Detector System Trigger Hodoscopes - design drawings from JMU group. Hall C at 12 GeV

  32. The SHMS Detector System Optimizing Heavy Gas Cerenkov -- University of Regina Group Hall C at 12 GeV

  33. The SHMS Detector System Yerevan Group’s working drawings for the Calorimetry Hall C at 12 GeV

  34. The SHMS Detector System Calorimeter: e/π separation Yerevan Physics Institute Preshower: Re-use SOS Shower: Gift from HERMES             (NIKHEF, Vr.Univ. Amsterdam, Frascati, Yerevan, DESY) • Lead-Glass Block / PMT / Base Assemblies from HERMES • Low-Exposure modules from HERMES selected • Now On-Hand at JLab • Tests-to-Date indicate the modules are perfectly suitable for SHMS • Glass Transparency • PMT Gain • Stability Plan view Front Elevation Side Elevation Hall C at 12 GeV

  35. The SHMS Detector System • Trigger Hodoscopes: basic trigger; efficiency determination. • 3 Planes Scintillator Paddles + 1 Plane Quartz Bars S1X: 12 bars 8cm x 110 cm x 5mm S1Y: 14 bars 8cm x 90cm x 5mm S2X: 14 bars 8cm x 105cm x 5mm S2Y: 10 quartz bars: 11cm 115cm x 2.5 cm 0.5 cm overlap / 2 PMTs on each bar Hall C at 12 GeV

  36. The SHMS Detector System Heavy Gas Cerenkov: π/K separation for momenta > 3.4 GeV University of Regina • Gas choice now C4F8O (instead of C4F10) • Widely used in semiconductor industry • Many commercial suppliers • Much less expensive than C4F10 • Extensively studied by BTeV • Stable, non-toxic, non-explosive, non-reactive • Does not destroy ozone SLD ECRID Gas System Side Elevation Line Drawing Hall C at 12 GeV

  37. Approved Hall-C 12-GeV Experiments • Contributions: • Heavy Gas Cerenkov effort • SHMS Optics Design & Calculations • HB Magnet Heating R&D • GOALS: • Measurement of the Q2 dependence of the L and T cross sections for exclusive ep -> e’π+ n above the resonance region at fixed values of x and –t. • Does σL tend towards predicted Q-6 scaling? • Needs: • π+/K+ separation over 2.4-8.5 GeV/c • L/T separations require rigid attachment to pivot and frequent angle/momentum changes, as well as well-understood spectrometer acceptance. ep e’ π+ n HMS SHMS Hall C at 12 GeV

  38. SHMS Design Parameters 

  39. SHMS Shield House Electronics Room Cryo Transfer Line Power Supplies Target Bender Q1 Q2 Q3 Dipole Detectors Hall C at 12 GeV

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