1. The NPD  Experiment David Bowman IScientific goals IIStatus

2. NPD  Collaboration Institutions –Dayton, Dubna, Hamilton, Indiana, Jlab, KEK, LANL, NIST, ORNL, TRIUMF, Berkeley, Manitoba, Michigan, New Hampshire, Tennessee Sponsors –DoE, NSF, NSERC, LANL, collaborating institutions

3. Scientific goal of the experiment

4. Hadronic weak interaction Weak NN force interferes with the strong NN force. Changes parity of the NN pair. Changes I NN by 0, 1, or 2. Produces parity-violating admixtures in nuclear wave functions and PV asymmetries HWI is described by a meson exchange potential

5. The value of is controversial 18 F gamma circular polarization experiments give 0. Haxton interprets result to give =0±1.0 10 -7. 133 Cs anapole moment gives non-zero value. Flambaum interprets result to give =7±3 10 -7. The goal of the NPD  experiment is to measure with an accuracy of 0.5 10 -7. Goal error is 5% of the DDH reasonable range.

6. Status of NPD  experiment 04-5 commissioning run complete 06 production at LANSCE –Measure A  to ±10 -7 Move to SNS in 06-7 –Measure A  to ±10 -8

7. Apparatus to measure A 

8. Neutron Intensity Monitors

9. 3 He neutron polarizer

10. Determine 3 He polarization Stable operation for several weeks 3 He polarization = 46±2%

11. Commissioning the RFSR FP12 neutron guide RF Spin Rotator 3 He Spin Filter M1 M2

12. Spin-flipper efficiency Preliminary

13. Liquid Para-Hydrogen Target 20 liter liquid volume, 30 cm diameter and 30 cm long Absorbs 65% of neutron beam 1% neutron depolarized at 17K (0.05% of LH 2 in ortho-state) due to large scattering cross section No false asymmetries from target material Use 6 Li to shield CsI from neutrons Ortho (total) Para (total) Capture cross section

14. CsI detector 48 (15cm) 3 modules

15. noise/counting statistics Electronic noise << counting statistics Experiment operates close to counting statistics limit

16. Electronic asymmetries (beam off) Time to determine electronic asymmetries << run time False asymmetries are  10 -8 Asymmetry (10 -8 ) Time (hours) Additive-0.1±.35 Multiplicative-0.8 ±.511

17. Measured asymmetries Time to determine background asymmetries << run time False asymmetries ~ asymmetry  f-bkg are  5 10 -8 Material Time (shifts) f-bkg (%) U-D (PV) Asy.(10 -6 ) L-R (PC) Asy.(10 -6 ) Al21.6. 0.0±0.3 0.2±0.3 Cu.52. 1.2±2.5-0.3±2.5 B.50.7 1.3±2.3-4.5±3.3 In.50.4-3.2±2.3-3.0±2.5 Cl1.0.0 19.2±2.0 0.6±2.0

18. Spin interactions

19. Estimated sizes of false asymmetries

20. Apparatus performance All components of the apparatus performed as designed Several physics measurements have been

21. LH target must be finished, tested, and installed We request a thorough-going safety review to insure a safe target.

22. Beam time request The estimate is based on measured performance – 3 He polarization =.55 –Cell diameter = 10 cm Projected FPNB projected intensity 7000 MWh for data and systematics 1000 h at >,14 MW for tuning and systematics

23. Schedule We request that NPD  run after the beam line is commissioned –9/06Move to SNS –9/07Beam line ready –12/07Experiment installed –3/08Commissioning complete –6/08Start production

24. Geoff’s questions Technical issues - hydrogen target Funding $K 2500 already spent for apparatus at LANL –20transport to SNS –160shielding –20supports and stands –20Air conditioning –130target infrastructure –30instrumentation/cabling Safety - hydrogen target Complex installation - one block ~ 40 users 3 PhD’s to date, trained several undergraduate students, Expect several PhD’s from SNS run