1. 2007/11/02nEDM Meeting @ BOSTON1 Dressing Field Study Pinghan Chu University of Illinois at Urbana-Champaign nEDM Collaboration Meeting @ Boston Dressed Spin in nEDM Study with polarized 3He beam Study with polarized 3He in cell Comparison between experiments and calculations Future Plan

2. 2007/11/02nEDM Meeting @ BOSTON2 Dressed Spin in Neutron EDM Neutrons and 3 He naturally precess at different frequencies (different g factors) Applying a RF field (dressing field), B 1 Sin(  d t), perpendicular to the constant B 0 field, the effective g factors of neutrons and 3 He will be modified (dressed spin effect) At a critical dressing field, the effective g factors of neutron and 3He can be made close!

3. 2007/11/02nEDM Meeting @ BOSTON3 Dress field can modify neutron and 3 He g factors: Critical dressing of neutrons and 3 He 3 He neutron 1.19 3.86 6.77 9.72 Effective dressed g factors: X=  n B 1 /  d X=1.19

4. 2007/11/02nEDM Meeting @ BOSTON4 Measurement using polarized 3 He Beam 1 K cold head Injection nozzle Polarizer quadrupole Spin flip region Analyzer quadrupole 3 He RGA detector B 1 dressing B 0 static Polarizer Analyzer RGA 36 in 3 He Spin dressing experiment Ramsey coils

5. 2007/11/02nEDM Meeting @ BOSTON5 Observation of 3 He dressed-spin effect Esler et al, nucl-ex/0703029, to appear in Phys. Rev.

6. 2007/11/02nEDM Meeting @ BOSTON6 The Goal of the UIUC measurement 1.To explore other dressing field settings (different B 0, B 1 and  d ). 2.To explore the dressed spin effect of polarized 3 He in a cell at room temperature (rather than polarized 3 He beam). 3.Dressing effect for 3 He in superfluid 4 He 4.The effect of the dressing field on the 3 He relaxation.

7. 2007/11/02nEDM Meeting @ BOSTON7 Experimental Setup @ UIUC Z X Dressing Coils  /2 Coils RF discharge 3 He Cell Laser B 0 Coils B0B0 Photo diode B1B1 Pickup Coils

8. 2007/11/02nEDM Meeting @ BOSTON8 Experimental Setup @ UIUC Pickup Coils 3 He Cell  /2 coils Dressing Coils Helmholtz Coil Pair Laser

9. 2007/11/02nEDM Meeting @ BOSTON9 Experimental Setup @ UIUC DAQ

10. 2007/11/02nEDM Meeting @ BOSTON10 Experimental Steps 1.Polarize 3 He nuclear spins. (Metastability exchange with optical pumping) (by Laser and B 0 )  /2 burst to rotate the spin to x-y plane. (by B  /2 Sin(  0 t)) 3.Apply dressing field, B 1 Sin(  d t), and measure precession frequency by the pickup coils and Lock-in amplifier. X Y Z X Y Z X Y Z B0B0 B0B0 B0B0  /2 burst NMR signalPolarize spins B  /2 Sin(  0 t)B 1 Sin(  d t)

11. 2007/11/02nEDM Meeting @ BOSTON11 To Polarize 3 He with metastability exchange C9C9 C8C8 C9C9 Circular Photons RF discharge Metastability Exchange fluorescence light (optical signal) Optical Pumping Laser Frequency Diode signal Deplete m F = -3/2,-1/2 states

12. 2007/11/02nEDM Meeting @ BOSTON12 TbTb Optical Signal 1.Demonstrate 3 He polarization.  /2 coils or dressing coils magnetic field calibration. Applying a continuous rotating field

13. 2007/11/02nEDM Meeting @ BOSTON13 Pickup Coils Signal *Lockin Reference freq = Precession freq

14. 2007/11/02nEDM Meeting @ BOSTON14 Dressed Spin Effect (Measurement) [Volts] Pickup Amplitude (A)

15. 2007/11/02nEDM Meeting @ BOSTON15 Dressed Spin Effect (For Y<1) Y=0.423 Y=0.176  dressed /  Bessel Function J0

16. 2007/11/02nEDM Meeting @ BOSTON16 Dressed Spin Effect (For Y>1) Y=7.153 Y=4.763 Y=2.381 Y=1.43  dressed / 

17. 2007/11/02nEDM Meeting @ BOSTON17 Dressed Spin Effect C. Cohen-Tannoudji and S. Haroche, J. Phys. (Paris) 30, 125, 153 (1969) 6x6 46x46 Jaynes-Cummings Hamiltonian

18. 2007/11/02nEDM Meeting @ BOSTON18 Dependence of effective  in dressing field Without dressing field

19. 2007/11/02nEDM Meeting @ BOSTON19 Dependence of effective  in dressing field With dressing field

20. 2007/11/02nEDM Meeting @ BOSTON20 Dressed Spin Effect (For Y<1) Y=0.423 Y=0.176  dressed /  Bessel Function J0

21. 2007/11/02nEDM Meeting @ BOSTON21 Dressed Spin Effect (For Y>1) Y=7.153 Y=4.763 Y=2.381 Y=1.43  dressed / 

22. 2007/11/02nEDM Meeting @ BOSTON22 Future Plans Study dressing field effect in different situation at room temperature and further in the low temperature, Study of systematic uncertainties, Study the effect of the dressing field on 3 He relaxation time.

23. 2007/11/02nEDM Meeting @ BOSTON23 Acknowledgment D. Beck, S. Clayton, A. Esler, J.-C. Peng, S. Williamson, J. Yoder. J. Blackburn, E. Thorsland B.-Z. Hu, S. Y. Ngan, C. H. Sham, L, H. So (Summer Student) Z. H. Yu, M. H. Yung (Theory)

24. 2007/11/02nEDM Meeting @ BOSTON24 Bloch Equation Simulation Undressed 3He and Neutron Spins Dynamics http://www.youtube.com/watch?v=7V3lUVWFybE Undressed 3He spin and dressed 3He spin http://www.youtube.com/watch?v=L-dF3Vca5PA Dressed 3He and Neutron Spins Dynamics http://www.youtube.com/watch?v=vlPHb-DeCMc