SBS GMn Collaboration Feb 23 2018 GMn Preparation

SBS (GMn) Collaboration Feb. 23, 2018 GMn Preparation Status Overview ERR Update Scheduling Run Plan Hardware Status Brian Quinn -- Carnegie Mellon Univ. 1

Overview E 12 -09 -019 (GMn) Precision Measurement of the Neutron Magnetic Form Factor up to Q 2=13. 5 (Ge. V/c)2 by the Ratio Method B. Quinn, J. Annand, R. Gilman, B. Wojtsekhowski Hall A collab Approved by PAC 34 PAC 35 allocated 25 of requested 31 days. 2

Technique Many systematic effects (experimental and theory) cancel in ratio. Expect very small correction for Electric because small form factor and large kinematic weighting of Magnetic 3

Schematic Experiment Layout Big. Bite as electron arm (Beam left) Identifies q-vector Fiducial cut in Big. Bite selects high, matched acceptance for n and p. 48 D 48 (SBS spectrometer magnet) Deflects protons vertically on HCal-J to distinguish from neutrons HC AL flig h t pa th 6 . 2 - 17 m HCal-J as hadron detector with CDet in front (Beam right) SBS: 1 st Experiments, J. R. M. Annand et al. 4

GMn ERR March 21, 2017 June 15 -16 (July 13 -14 July 18 July 21 July 24 July 27 ERR charge given ERR / recommendations given SBS collaboration meeting) Response to ERR recommendations Many thanks Eric, Andrew, Seamus, and many others Additional questions (minor) Response to additional questions GMn passed ERR Still work to do on OSPs, ESAD… 5

Scheduling GMn not scheduled by last Scheduling Committee mtg. (Not surprising – 2019 not covered) BUT latest planning for Hall A running: 2018 Tritium 2019 APEX, PREX 2, CREX (assumes summer running for PREX 2) 2020 SBS installation 6

proposed configuration Q 2 Run Plan q. BB EBeam (Ge. V/c)2 (Ge. V) (deg. ) q. SBS d. BB d 48 D 48 field Luminosity d. HCal (deg. ) (m) integral (T-m) (1038/A/cm 2/s) (m) 1 3. 5 4. 4 32. 5 31. 1 1. 80 2. 00 1. 40 0. 7 6. 2 2 4. 5 4. 4 41. 9 24. 7 1. 55 2. 25 1. 70 1. 4 6. 2 3 6. 0 4. 4 64. 3 15. 6 1. 55 2. 25 0. 70 2. 8 11 4 8. 5 6. 6 46. 5 16. 2 1. 55 2. 25 1. 20 2. 8 11 5 10. 0 8. 8 33. 3 17. 9 1. 75 2. 25 1. 30 1. 4 13 6 12. 0 8. 8 44. 2 13. 3 1. 55 2. 25 1. 20 2. 8 14 7 13. 5 8. 8 58. 5 9. 8 1. 55 3. 10 0. 70 2. 8 17 8&9 3. 5/6. 0 calibration of HCal using L-HMS at kinematics of config. 1 &3 modified configuration Q 2 EBeam (Ge. V/c)2 (Ge. V) q. BB q. SBS d. BB d 48 D 48 field Luminostiy d. HCal (deg. ) (m) integral (T-m) (1038/A/cm 2/s) (m) 1 3. 5 4. 4 32. 5 31. 1 1. 80 2. 00 1. 71 0. 7 (2. 8? ) 7. 2 2 4. 5 4. 4 41. 9 24. 7 1. 55 2. 25 1. 71 1. 4(2. 8? ) 8. 5 3 5. 7 4. 4 58. 4 17. 5 1. 55 2. 25 1. 71 2. 8 11 4 8. 1 6. 6 43. 0 17. 5 1. 55 2. 25 1. 65 2. 8 11 5 10. 2 8. 8 34. 0 17. 5 1. 75 2. 25 1. 60 6 12. 0 8. 8 44. 2 13. 3 1. 55 2. 25 1. 50 2. 8 14 7 13. 5 11. 0 33. 0 14. 8 1. 55 3. 10 0. 97 2. 8 17 8 9 q. L-HRS 1. 4(2. 8? ) 11 6. 06 4. 4 61. 1, 64. 3 14. 8 3. 10 1. 71 0. 93 17 4. 4 67. 5, 70. 7 4. 4 39. , 42. 25. 5 3. 10 1. 71 0. 93 7 17

Schematic Experiment Layout with GEn 4. 5 (Ge. V/c)2 Kinematic Setting HC AL flig h t pa th 6 . 2 - 17 m Analyzer and GEM trackers for Gen/Gmn Remove analyzer blocks for GMn/GMp In-acceptance GEM may be useful for GMn/GMp SBS: 1 st Experiments, J. R. M. Annand et al. 8 25 th Jan. 2018

config Changes required 1 reposition 48 D 48, HCal, Big. Bite (Insert GEn polarimter, GEn run, remove GEn analyzer) Before Kin 2? ? 2 reposition 48 D 48, HCal, Big. Bite Total Energy change, reposition Big. Bite 1 Beam set-up 4 Energy changes 5 SBS 48 D 48/HCal moves 7 Big. Bite moves 1 Change of beamline 1 Rig out Big. Bite 6 HRS moves 3 4 Energy change, reposition Big. Bite 5 reposition 48 D 48, HCal, Big. Bite 6 reposition 48 D 48, HCal, HRS , Big. Bite change beam pipe Energy change 7 Energy change/rig out Big. Bite 8 3 HRS moves (3 degrees each) reposition 48 D 48, HCal, HRS 9 one HRS move (3 degrees) 9

Hardware Status Big. Bite as electron arm (Beam left) Instrumented for high luminosity (GEMs) 30 u. A on 15 cm LD 2 (or 45 u. A on 10 cm) 1. 4 X 1038 /cm 2/s Good electron ID (preshower/shower & GRINCH) W ~ 55 msr dp/p ~ 0. 5% dq ~ 1 mr dz ~ 2 mm @ target dt ~ 150 ps Identifies q-vector ( ) ~10 mrad resolution needed Single-arm trigger efficiency NOT critical Count event only if BOTH n and p would be in highacceptance region of HCal-J Loading of detector frame expected this summer 10

48 D 48 (SBS spectrometer magnet) Up to 1. 71 T-m ‘kick’ to separate protons from neutrons Field uniformity, accurate map not important – Not used as spectrometer Ready for installation CDET In front of HCal, hanging from HCal frame Positive ID of proton (useful check for proton efficiency calibrations). Vertical hit position, useful for calibrating HCal-J position resolution (not included in original proposal) Construction, testing of submodules in progress.

HCal-J as hadron detector (Beam right) Similar (high) efficiency for neutrons and protons Good position resolution to test whether hit is associated with known q-vector Cuts inelastics. Fermi-motion sets resolution limit. No tracking detectors needed in hadron arm TOF information will improve inelastic rejection (not included in proposal) All modules built, final delivery next week. Sub-assemblies being assembled. Installation of pulser system & PMTs this summer. Start calibration. >93% efficiency for multi-Ge. V p and n Effective suppression Of soft background 12 ~0. 5 ns timing resolution 12

Conclusions In < 2 years we must: complete all detectors assemble all electronics obtain all cables prepare DAQ & analysis for each system test all systems from detector to DAQ to analysis 13

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Backup slides 15

Q 2 3. 5 4. 5 5. 7 8. 1 10. 2 12 13. 5 theta_pq (angle) 2. 5° 2. 3° 2. 0° 1. 1° 0. 9° 0. 7° 0. 6° distance from proton-neutron theta_pq [cm] 31. 42 85. 29 34. 12 86. 52 38. 40 104. 47 21. 12 74. 74 17. 28 59. 34 17. 10 66. 32 17. 80 45. 59 16

Singles QE plus background rates: Q^2 n+p QE xsec design L(per atom) QE rate Total rate Ge. V^2 fb X 10^38/cm^2/s Hz Hz 3. 5 6700 0. 35 2100 4. 5 1015 0. 7 70 1400 5. 7 97. 9 1. 4 13. 5 140 8. 1 47. 4 1. 4 6. 6 390 10. 2 31. 6 0. 7 1. 5 210 12. 0 5. 04 1. 4 0. 7 200 13. 5 6. 25 1. 4 0. 87 100 17

Coincidence rates Q 2 Protons Neutrons [Ge. V^2] [counts/hr] 3. 5 145348 52925 4. 5 77369 27060 5. 7 19510 6615 8. 1 6981 2407 10. 2 1407 503 12 664 246 13. 5 512 196 Q 2 3. 5 4. 5 5. 7 8. 1 10. 2 12 13. 5 Protons Neutrons 40. 37 14. 70 21. 49 7. 52 5. 42 1. 84 1. 94 0. 67 0. 39 0. 14 0. 18 0. 07 0. 14 0. 05 18

Expected workforce availability from outside JLab for installation, testing, calibration 8 months before experiment (person-months) Faculty 47 Postdoc 22. 8 Graduate students 64. 5 Technician 5 undergrad 14 Total 153. 3 Expected workforce availability for running shifts (if over 3 months) Faculty Postdoc Graduate students undergrad 13 9. 2 29 1 Total 52. 2 19

~8 months installation/callibration/tesing undergra faculty postdoc grad stu d tech. Argonne S. Riordan Cal. State L. A. K. Aniol CMU B. Quinn Christopher Newport P. Monaghan Glasgow J. Annand Hampton M. Kohl Idaho State M. Khandaker ? INFN/Bari S. Marrone ? INFN/Catania V. Belini INFN/Genoa P. Musico INFN/Rome E. Cisbani Norfolk State V. Punjabi NC A&T A. Ahmicouch NC Central C. Jackson James Madison G. Niculescu JLab B. Wojtsekhowski N/A U. Conn. A. Puckett U. Va. G. Cates " St. Mary's A. Sarty Stony Brook K. Kumar Yerevan A. Shahinyan 0. 7 3 4 1. 3 4 6 8 1 0. 8 1 4 3 4 1 2 1 1 0. 5 3 1. 75 3 1 2 4 2 0 0 8 2 0 4 16 8 0 0 0. 75 1 1. 5 1 8 6 faculty postdoc grad stu other 0. 7 3 3 6 1 0. 5 1 0. 75 1 1 0 1 1 1 0 0 0 3 0. 5 1. 5 6 3 0 0 0. 5 3 3 1 ? 7 1 1 3 3 1 ? William & Mary T. Averett R. Gilman other ? N. Liyanage Rutgers ~3 months running ? 12 20