g2p/GEp Preparation Overview Jian-ping Chen g 2 p /G ep Readiness Review 5/6/2011

REGION 1 REGION 2REGION 3 REG 4 REGION 5 Slow Raster FZ1 FixedStand FZ2 Telescoping Stand DUMP TARGET Polarized Solid NH 3 Target (Hall C/UVa target) Target material irradiation Beamline (Similar to Hall C) Magnetic Chicane/Beamline modifications. Low beam current BCM/BPMs, Slow Raster Hall A Engineering/Design Local Beam Dump Septum Magnets Hall Infra-structure/Chamber/ Target/magnet mount Simulations/Optics/Spectrometer/Detectors/QAD Polarimetry/3 rd arm BPMs Use existing equipments Hall C beamline/target Keep change minimum modify the existing PREX septa Major equipments for g 2 p /G E p experiments Septa/HRS

Goal is to measure g2p in the low Q2 region with a precision ~ 5-7% by measuring transversely polarized cross section difference = A x Measure both asymmetries and cross sections to 4-5% In addition to statistics, we need to control total systematics to 3-5%, i. e., each system to be below that (1-3%). Main systematics for asymmetries: Target polarization (3-4%) Beam polarization (2-3%) Dilution factor/packing factor (some cancellation) Main systematics for cross sections Acceptance/optics (~3%) Dilution factor/packing factor (some cancellation) Density (2-3%) Beam charge (1-2%) Position and angle determination ( mm, degree) Detector efficiencies (~< 1%) Background (pions, …) (1%) Radiative corrections (including radiative tails) (1-4%) … Experimental Goal/Considerations

Significant Progress in Beam Line System (T. Michalski, weekly meeting) Overview design, Region 1 and Region 2 design completed (B. Dillon-Townes) Region 3 design near completion Existing hardware items (magnets, raster, power supplies) located Most parts are ordered, machined, arriving New items (BPM/BCM electronics, Harps, BD magnets) are being taken care of BPM tests (J. Musson) BCM tests (A. Camsonne/P. Zhu) Silver Calorimeter Installation plan worked out with the 6-month-down master plan Safety/PSS Target Progress (C. Keith, bi-weekly meeting) Magnet repaired and back to JLab Design progressing well Parts are being ordered, manufactured Rotating Seal Target insertion Target material irriadiation at NIST planned (June, D. Crabb) Cold-down test Alignment Cryogenics Full polarization test Safety consderations Overview of Progress (I)

Hall A infrastructure, Beam dump, Septum (A. Gavalya, frequent meeting) Pivot platform layout Septum modification completed (Ed) and tested at low current. Septum field effects on target (Robin Wines) Scattering chamber Beam dump Radiation consideration Simulations/HRS with septa (Jixie Zhang, Min Huang,… weekly meeting ) Target field effect on kinematics Run plan optimization (Karl) Optics/calibrations Polarimetry: Moller (old-style), will work with both straight-through and chicaned beam 3 rd arm detectors (K. Allada, C.Gu) Monitoring (relative) beam and target polarizations Detect protons at 72 degrees Simple DE (thin) & E (thick) scintillators Overview of Progress (II)

3.4 GeV, 12.5 deg 2.3 GeV, 12.5 deg 3.4 GeV, 6 deg 2.3 GeV, 6 deg 1.7 GeV, 6 deg 1.2 GeV, 6 deg Polarized beam: nA up to 1 uA for optics Polarized NH 3 target at 5T, 1K Slow Raster mm diameter G e p configuration is basically g 2 p at the elastic setting Two configurations: with septa (6 degree) (target at 87 cm upstream) and without septa (12.5 degrees) (target at original pivot) G 2 p : target at 90 degrees for all and 0 degree for 3.4 GeV G E p : target at 20 degree Kinematic Settings (target field effect not taken into account)

3.4 GeV, 12.5 deg 2.3 GeV, 12.5 deg 3.4 GeV, 6 deg 2.3 GeV, 6 deg 1.7 GeV, 6 deg 1.2 GeV, 6 deg Polarized beam: nA up to 1 uA for optics Polarized NH 3 target at 5T, 1K Slow Raster mm diameter G e p configuration is basically g 2 p at the elastic setting Two configurations: with septa (6 degrees) (target at 87 cm upstream) and without septa (12.5 degrees) (target at original pivot) G 2 p : target at 90 degrees for all and 0 degree for 3.4 GeV G E p : target at 20 degree Kinematic Settings (WITH target field effect)

3.4 GeV, 12.5 deg 2.3 GeV, 12.5 deg 3.4 GeV, 6 deg 2.3 GeV, 6 deg 1.7 GeV, 6 deg (2.5T) 1.2 GeV, 6 deg (2.5T) Lower target field from 5T to 2.5T for two lowest energy settings (Raise target by 9 cm for the lower 3 settings) Try to minimized impacts 1) 2.5 T leads to lower polarization and time needed for NMR and switch-over. 2) 70 GHz EIO (Don, ok), nose piece (target group). 3) Addition optics settings for beam (Yves, done) and chicane settings (Stephanie, done). 4) Beam dump, scattering chamber (Al). 5) G E p : target at 20 degree, smaller effects. Kinematic Settings (Proposed New Settings)

Target safety: Following all the safety considerations as in SANE experiment in Hall C Additional controls in the target area (Chris/Ed/Tim) Beamline safety: PSS system to include new changes (Chicane/target/dump) (Tim) Ion chambers, viewers, thermal couples (dump) Radiation consideration: LC dump design: worked closely with RADCON group (Al) RADCON group helped with calculations of radiation levels Safety documents: RSAD (draft) already done Will work closely with RADCON group to have other radiation related documents in place ESAD for each sub-systems will reflect new changes Safety Considerations and Documents

Cost: A) Procurement part consistent with initial estimation within expectation Beam line procurement: 14 BMP electronics (absorbed in Hall A cap, ok) B) Manpower Service provider (engineering) significant increase (resolved now, ok) FY11 addition funding from DOE has been confirmed on the way. User groups contribution to procurement/machining : UVa (Don/Donal): target magnet repair, material irradiation Temple (Zein-Eddine): procurement Rutgers (Ron): machining + procurement UVa (Nilanga): machining HUJI (Guy): machining + procurement UNH (Karl): procurement Nice to have these contributions Users will continue to contribute during installation period Users onsite manpower build up nicely (next slide) Budget and User Contributions

Onsite User/Hall A People Power PhD Students: (5-7) Pengjia Zhu (USTC, advisor: Yunxiu Ye), 3 rd year, onsite, (beamline, target) Min Huang (Duke, Haiyan Gao), 3 rd year, onsite, (simulation, optics, HRS)) Chai Gu (UVa, Nilanga Liyanaga), 2 nd year, onsite, (3 rd arm, simulation) Melissa Cummings (W&M, Todd Averett), 2 nd year, onsite from 5/2011, (HRS) Ryan and another (New Hampshire, Karl Slifer), 2nd year, onsite from 5/2011, (run plan) A student from Temple (Zein-Eddine Meziani), 2 nd year, onsite from 5/2011? Postdocs: (3 + a few part time) Kalyan Allada (Hall A), beamline, 3 rd arm Jixie Zhang (Hall A): simulation, optics James (UVa New Hampshire): target, starting in the summer Xiaohui Zhan (Argonne) (onsite now), busy with other tasks (x>2 experiment) Narbe Kalantarians(UVa): part time Hovhannes Baghdasaryan (UVa): part time Sarah Philips (New Hampshire): part time? Physicists: Jian-ping Chen (Hall A): Project manager, overall coordination Alexandre Camsonne (Hall A): Beam line, DAQ Karl Slifer (New Hampershire): Overall consideration, run plan, … Guy Ron (HUJI): GEp consideration Doug Higinbotham (Hall A) (more available after SRC experiments) …

People Power and Tasks Overall coordination: Project manager (Jian-ping Chen, Hall A) Project coordinator for beamline (Tim Michalski, engineering division) Collaboration contacts: Karl Slifer (g2p), Guy Ron (GEp) Beamline Engineering Division/Accelerator Division (Tim Michalski coordinator) Engineer/design (Butch Dillon-Townes) Installation (Neil Wilson) Instrumentation/magnets/vacuum/alignment/software/radcon groups, as identified in 6-month-down schedule/planning Users (Alexandre Camsonne and Pengjia Zhu) on BCM/BPM/Slow raster… Target Target Group (Chirs Keith) UVA(Don Crabb, Donal Day, psotdocs and students) New Hampshire (Karl Slifer, James Maxwell) Other postdocs/students Hall A engineering/design: Septa/LC Dump/Pivot Layout … Hall A engineering/design team (Robin Wines, Al, Gavalya) With input from the collaboration Hall A installation Hall A installation team (Ed Folts) Simulation/optics/HRS/detectors/DAQ/3 rd Arm Users(Physicists/postdocs/students)

Main Items, each has its schedule and milestones (separate talks) Beamline Target Hall infrastructure, beam dump, septa Installation May, 2011, Main design complete. End of May, 2011 Target magnet cool-down in EEL July, 2011, Parts manufactured and arrived Aug 3, 2011, Beamline region 1 installation complete Aug 16, 2011, Beamline region 2 installation complete Mid-late Aug, 2011, Target test in EEL Sept 1, 2011, Septa, LC beam dump, scattering chamber installed. Sept 1, 2011, Target move to Hall A for installation Sept 15, 2011, Beamline region 3 installation complete Oct 1, 2011, Dump/target/magnet/chamber alignment complete Oct 10, 2011, Beamline alignment complete Nov 14, 2011, Target cool-down/polarize Nov 19, 2011, Experiment Commission Starts Jan 23 – March16, 2012, Remove Septa, Move Target back to Pivot May 2012, End of experiment data taking Schedule and Milestones