Neutral Particle Spectrometer (NPS) + Compact Photon Source with Longitudinal & Transverse Polarized NH 2 Experiment Exp # Beam Target PAC Days Rating π 0 SIDIS " – E12-13-007 ⃗ L H 2 26 A – " – DVCS and Exclusive π 0 E12-13-010 ⃗ L H 2 53 = (26)+27 A Wide Angle Compton Scattering A – " $ , & (WACS) E12-14-003 L H 2 18 Wide Angle Exclusive p 0 " $ , & photoproduction E12-14-005 L H 2 (18) B Initial State Helicity Correlation in WACS E12-14-006 CPS: ⃗ & '( ) 31 B A LL & A LS Polarization Observables in WACS at large s, t, and u C12-17-008 CPS: ⃗ & '( ) 46 A – Timelike Compton Scattering (TCS) off a Transversely Polarized Proton Hall C Winter Meeting C12-18-005 CPS: ⃗ & 35 C2 [ '( ) ] T Charles Hyde, Hall C Meeting, 28–29 Jan 2019
� NPS Layout on SHMS Carriage g p • WACS H( g , g p), Wide angle H( g , p 0 p) • DVCS H(e,e’ g )p, Deep H(e,e’ p 0 )p NPS cantelevered off SHMS platform NPS on SHMS platform Proton to HMS Magnet Magnet PbWO 4 Detector g - Detector NPS angle range: 5.5 – 30 degrees NPS angle range: 25 – 60 degrees e – to HMS � January 28, 2019 NPS C. Hyde 2
Sweep Magnet replaces SHMS Horizontal Bender • Looking upstream � Vertical bend ~0.3 Tm • 1cm steel septum between 0-field beam pipe and g- aperture (at smallest angle setting) • Ready for power, cooling • Magnetic field mapper constructed at ODU January 28, 2019 NPS C. Hyde 3
PbWO 4 Crystal Procurement 2x2x20 cm 3 • SICCAS (China): 460 received, 160 failed specs, returned for replacement. Additional 52 below spec to be used at edges. • SICCAS: Contract to be signed for 400 more • Crytur (Czech Republic): 100 received, OK • Crytur: 250 crystals on order delivery ≤ October 2019 • Supply limited by PANDA order • Raw material reserve exhausted January 28, 2019 NPS C. Hyde 4
PMTs from HyCal, New Active bases • Gain stabilization at high rates by amplifier fed from last stage of HV divider. • PMT base assembly: Ohio U. • Prototype assembly: IPN-Orsay January 28, 2019 NPS C. Hyde 5
Calorimeter S Assembly i g HV n a l c a b 2 l e 5 s 0 t o M H z F A D C • Carbon fiber alveoli cantilever crystals in place Translation cards LED Ribbon January 28, 2019 NPS C. Hyde 6
Calorimeter Servicing • Access to remove any individual PMT+Base module without disassembly • Module disassembles from calo with a single screw LED fiber Signal + HV ribbon jumper January 28, 2019 NPS C. Hyde 7
Compact Photon Source for Polarized Targets N M R e s o w a v M i c r • Self-contained radiator, u m p s T o P e r a t o r R e r f i g forward collimator, & electron a l a y r S e R o t L N 2 dump L H e n g c a t t e r i o t r S S u p p • Pure photon beam on NH 3 e r h a m b R n i g s C L H e 0 o 1 K 1 0 e a m o t o n B P h g n e t o M a 3 8 � Longer polarization lifetime m 1 on view of the polarized target to be used by t � Higher g p luminosity � Transverse polarization • Dipole magnet, central Cu absorber/dump, W powder and borated plastic radiation absorber. • CPS concept Jlab Internal Review Committee 2018. Feasible and ready for detailed design January 28, 2019 NPS C. Hyde 8
WACS Polarization Observables • UVA n NH 3 target � 100° longitudinal aperture Microwaves NMR � 38° transverse aperture • A LL = K LL To Pumps � Except when it doesn’t. Refrigerator Rotary Seal � Free elementary quark (diluted by polarization) 1.2 0.40 LS LL • Kroll, Miller = LN2 This Proposal (S1 50 hours) JLab 6 GeV (K ) & K = -K LL This Proposal (S4 300 hours) 0.35 handbag 1.0 This Proposal (L1,L3 & L4 500 hours) LHe K-V (2015) JLab 6 GeV (K ) LL LS models 0.30 LS A 0.8 A D-K (2013) (different off- 0.25 K-V (2016) Scattering 0.6 shell) Chamber Miller K Support Kroll (2017) 0.20 LL Rings 0.4 • K-V = SCET 0.15 1K LHe Photon Beam D-K (2013) 0.2 o 100 0.10 Miller A 0.0 LL 0.05 Magnet - o 0.2 38 0.00 Miller (2004) - - 0.4 0.05 40 60 80 100 120 140 160 180 2 4 6 8 10 q 2 1 m [deg] -t [GeV ] cm January 28, 2019 NPS C. Hyde 9
Timelike Compton Scattering • Access to E ( x ,t) Compton Formfactor with 11 GeV Kinematic Coverage transversely polarized target. DVCS TCS • Quark Orbital Angular Momentum - - e (k) e (k) + e (k') e (k') + g g g* g* (q) (q) (q') (q') hard hard TCS TCS soft soft x+ x x- x x+ x x- x N (p) N' (p') N (p) N' (p') t t DVCS - e (k) e + (k’) g (q) g (q) - e + (k’) e (k) BH * * g g (q’) (q’) N (p) N (p) N’ (p’) N’ (p’) January 28, 2019 NPS C. Hyde 10
NPS • Equipment will be ready for beam before 2022 • Rich physics program • Join us! • https://wiki.jlab.org/cuawiki/index.php/Main_Page • Tanja Horn, coordinator January 28, 2019 NPS C. Hyde 11
Magnet Mapper • ODU graduate student Mitch Kerver at the controls • Hall Probe recording now added January 28, 2019 NPS C. Hyde 13
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