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Status update of n- 3 He experiment DOE FnPB Review, ORNL 2009-04-23

Status update of n- 3 He experiment DOE FnPB Review, ORNL 2009-04-23. D. Bowman, S. Penttila Oak Ridge National Laboratory M. Gericke University of Manitoba C. Crawford, Y. Shin University of Kentucky. Executive summary Scientific motivation theory calculations statistical sensitivity

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Status update of n- 3 He experiment DOE FnPB Review, ORNL 2009-04-23

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  1. Status update of n-3He experimentDOE FnPB Review, ORNL 2009-04-23 D. Bowman, S. Penttila Oak Ridge National Laboratory M. Gericke University of Manitoba C. Crawford, Y. Shin University of Kentucky

  2. Executive summary Scientific motivation theory calculations statistical sensitivity systematics negligible Experimental design experimental layout solenoid design spin flipper design 3He target / drift chamber R&D at LANL Experimental team Projected schedule Funding profile FnPB infrastructure needed Summary Outline

  3. Executive summary • n-3He experiment approved by the FnPB PRAC, 2008-01-07 • first measurement of PV in the n-3He reaction • recent progress in experimental design • full 4-body calculation of PV observable • R&D projects on target/detector design at LANL • new spin flipper design permitting compact / less expensive layout • preliminary holding field design • leverage existing hardware / technology • major components based on similar NPDGamma instrumentation • can reuse NPDGamma electronics / power supplies • capable experimental team • experience on hadronic PV experiments at LANL • funding profile • University of Manitoba $100k target / drift chamber NSERC funded • University of Kentucky $ 57k DAQ / electronics DOE-OJI proposal • ORNL operation $120k solenoid, spin flipper, shielding, alignment, design • FnPB infrastructure • no safety hazards, no LH2 target, new power or cooling requirements • minimal modification of FnPB cave – stand for n-3He solenoid • technician support for readiness review preparation, setup of experiment

  4. Hadronic Weak Interaction (HWI) p-p and nuclei N N STRONG (PC) WEAK (PV) Meson exchange N N Meson Exchange model (DDH) Effective Field Theory (EFT)

  5. n-3He PV Asymmetry • 4He J =0+ resonance • sensitive to EFT couplingor DDH couplings • ~10% I=1 contribution(Gerry Hale, qualitative) 20.578 19.815 PV observables: ~ kn very small for low-energy neutrons S(I): - essentially the same asym. - must discriminate between back-to-back proton-triton Tilley, Weller, Hale, Nucl. Phys. A541, 1 (1992)

  6. Theoretical calculations – progress • Vladimir Gudkov (USC) PV A = 3£10-7 • PV reaction theory • Gerry Hale (LANL) PC Ay(90±) = -1.7±0.3£10-6 • R matrix calculation of PC asymmetry,nuclear structure , and resonance properties • Anna Hayes (LANL) • No-core shell model calculation with AV18 potential, etc. • Michele Viviani et al. (INFN Pisa) PV A = 3£10-7 • full 4-body calculation of scattering wave function • calculation of asymmetry within DDH framework • progress on calculation of EFT low energy coefficients • preliminary – still improving convergence of 0+ wave functions

  7. Experimental sensitivity to DDH couplings Viviani et al. preliminary Az cont. n+3Het+p (ppm) -0.1821 -0.830 -0.1447 2.373 0.0267 -0.074 0.0012 -0.016 -0.1269 -0.410 0.0495 0.096

  8. Experimental setup -metal shield 10 Gauss solenoid 1010 steel flux return • longitudinal holding field – suppressed PC asymmetry • RF spin flipper – negligible spin-dependent neutron velocity • 3He ion chamber – both target and detector supermirror bender polarizer (transverse) FnPB cold neutron guide 3He Beam Monitor transition field (not shown) RF spinrotator 3He target / ion chamber FNPB n-3He

  9. Solenoid holding field 10 Gauss solenoid 1010 steel flux return • uniformity requirements • B~ 0.3 G ¢B/2En=10-10 < Az • z ~ 0.1± + alignment of wires • preliminary design • solenoid with compensation coils at end for uniformity • -metal shield for residual earth’s field • 1010 steel flux return to prevent saturation of -metal • design parameters • 3 m length x 50 cm diameter • B =10 G for spin flipper • j = 9 A/cm winding density • I0 = 1560 A (or end-cap windings) • simulation using COMSOL 3 m £ 50 cm diam. 4 m £ 55 cm diam. I0=1500+60 A turns I0 j = 8+1 A/cm

  10. Radio frequency spin rotator Magnetostatic calculation with COMSOL • extension of design for NPDGamma • P-N Seo et al., Phys. Rev. ST Accel. Beam, vol 11, 084701 (2008) • new resonator for n-3He experiment • transverse horizontal RF B-field • longitudinal / transverse flipping • no fringe field - 100% efficiency • compact geometry - efficient • small diameter solenoid • matched to driver electronicsfor NPDGamma spin flipper • prototype design • parasitic with similar design for nEDM guide field near cryostat • fabrication and testing at UKy – 2009 red - transverse field lines blue - end-cap windings NPDGamma windings n-3He windings

  11. MC simulations of sensitivity to proton asymmetry including wire correlations  A ~ 6 /pN tests at LANSCE FP12 fission chamber flux calibration prototype drift chamber R&D new beam monitors for SNS design of new ion chamber for NPDGamma, test at LANL 3He target / ion chamber

  12. LANSCE FP12 absolute neutron flux

  13. LANSCE FP12 3He chamber R&D

  14. LANSCE FP12: test of NPDGamma monitors Left: LANL FP12 beam line with new beam monitor Below: new beam monitor signal at 100 mA proton beam current and neutron beam cross-section. Inverted Signal

  15. Comparison of beam monitors (same gain) RMS New monitors for SNS RMS Old monitors used for NPDGamma at FP12

  16. n-3He collaboration • J.D. Bowman (PI), S.I. Penttilä Oak Ridge National Laboratory • M.T. Gericke (PI), S.A. Page, Mark McCrea University of Manitoba • C.B. Crawford (PI), Y. Shin, E. Martin University of Kentucky • C. Gillis, J. Mei Indiana University • J. Martin University of Winnipeg • V. Gudkov University of South Carolina • M. Viviani INFN, Sezione di Pisa • A. Klein, A. Salas-Bacci, A. Hayes, G. Hale Los Alamos National Lab • R. Mahurin University of Tennessee • P.-N. Seo Triangle Universities Nuclear Lab • L. Barron Universidad Nacional Autónoma de México

  17. Jan 2010 – Jan 2011 NPDGamma data-taking Aug 2010 – Dec 2010 Construction of solenoid Test of field uniformity, alignment procedures Feb 2011 – Mar 2011 Installation at FnPB Commissioning Apr 2011 – Sept 2011 3He data-taking June 2009 – Aug 2010 Construction of new RFSF resonator at ORNL Construction of 3He ion chamber at Univ. Manitoba DAQ electronics and software production at Univ. Kentucky Sept 2010 – Nov 2010 test RFSF, 3He chamber, and DAQ at LANL FP12 Projected schedule ORNL Offsite, LANL window of opportunity for the n-3He experiment between NPDGamma and Nab (2011)

  18. Funding Profile • University of Manitoba $100k NSERC funded • target / drift chamber • $500k for FnPB-related activities in last 2 years • University of Kentucky $ 57k DOE-OJI proposal • DAQ / electronics • $40k university funding for R&D • ORNL operations $120k • solenoid, spin flipper • neutron, gamma shielding • design, stands, alignment • technician support

  19. Requirement of FnPB infrastructure • modification of FnPB • retained equipment: • polarizer, beam monitor, spin flipper electronics • computer interface to chopper and TOF from SNS • DC holding field supply • beam collimation and shielding, beam stop • support stand for solenoid • possible reuse of NPDGamma detector motion stand • power & cooling requirements • same as NPDGamma • manpower • shielding calculations, preparation for readiness review • 1 month technician support for setup of experiment • safety hazards – none • 3He target – 1 atm inert gas; n+3Het+p (no  radiation) • radiation shielding: polarizer is still the major background

  20. Conclusion • by doing NPDGamma, n-3He experiments along with existing p-p, p-, n- (few body systems) we can significantly improve statistical uncertainties in DDH couplings and eliminate nuclear structure uncertainties • EFT calculations are in progress for few-body systems • n-3He is on-track to run after NPDGamma

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