Laser Laboratory (-ies) Peter Müller

2 Search for EDM of 225 Ra Transverse cooling Oven: 225 Ra (+Ba) Zeeman Slower Optical dipole trap EDM probe Advantages: Large enhancement: EDM(Ra) / EDM(Hg) ~ 200 – 2000 Efficient use of 225 Ra atoms High electric field (> 100 kV/cm) Long coherence times (~ 100 s) Negligible “v x E” systematic effect

3 Search for EDM of 225 Ra Status: Trapped 225 Ra and 226 Ra EDM probing region constructed Torr, 100 kV/cm, 10 mG Next steps: Dipole trap transfer Optical pumping and detection 2 mm gap > 100 kV/cm ~ 1x Ra atoms

4 81 Kr / 39 Ar Atom Trap Trace Analysis Argon-39 : cosmogenic half-life = 270 a 39 Ar/Ar = 8 x Radio-Argon Dating : 50 – 1000 year range study ocean and groundwater previously with LLC and AMS Dark Matter Searches : LAr detectors (WARP, DEAP/CLEAN) 39 Ar major background search for old / depleted Argon WIMP Argon Programme Krypton-81 : cosmogenic half-life = 230 ka 81 Kr/Kr = 1 x

5 Atom Trapping & Nuclear Charge Radii of 6,8 He He-6: L.-B. Wang et al., PRL 93, (2004) He-8: P. Mueller et al., PRL 99, (2007) 389 nm 1083 nm Atom Trap Setup Single atom signal 8 He Spectroscopy

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7 Beta-Decay Study with Laser Trapped 6 He 6 He trapping rate: 1  10 4 s -1, 2  10 5 coincidence events in 15 min:  a = ± week:  a/a = 0.1% Simulated time-of-flight signal Standard Model New Physics 6 He yields: ATLAS: 1  10 7 s -1 CENPA: ~1  10 9 s -1 SARAF / SPIRAL2: ~1  s -1

8 Isotopic Menu for Laser Spectroscopy Low-energy yield, s -1 > < 1 Isotope shifts ->charge radii, deformations Hyperfine structure -> moments (dipole,…) ->spin

9 Laser Lab CARIBU AC HEPA Laser Enclosure (~ 6’ x 10’) Laser Table (~ 3’ x 7’) Ion Trap Collinear Beamline Tape Station Cf-252 source 80 mCi -> 1Ci High-resolution mass separator  m/m > 1/20000 Gas catcher RF Cooler & Buncher … starting in fall 2010

10 Linear Paul Trap for Spectroscopy PMT / EMCCD open geometry, linear Paul trap -> large light collection efficiency buffer gas w. LN 2 cooling, -> good spectroscopic resolution, quenching of dark states -> few (single ?) ion detection sensitivity ITO coated optics Ba + black, conductive coated electrodes

11 Ion Trap Spectroscopy at CARIBU Linear Paul trap for spectroscopy –Initially with neutron-rich Ba + –Isotope shift + moments (HFS) –Use RF cooler / buncher & transfer line To investigate: –optimized trap geometry and detection system –Buffer gas cooling + quenching (with H 2 ) –Cooling of trap with LN 2 Future: –other CARIBU beams High mass: Pr, Nd, Eu, … Low mass: Y, Zr, Nb, Sr, … –Yb + -> No + with ATLAS Upgrade Ba Isotopes

12 Collinear Laser Spectroscopy High spectroscopic resolution High sensitivity through bunched beams Neutral atoms w/charge-exchange Measure for the first time: Rh, Ru, … Extend isotopic chains on: Sn, Mo, Nb, … Other opportunities: Laser polarized beams, e.g., Kr, Xe … Laser polarization in matrix (solid noble gasses) Resonance ionization to suppress isobars/isomers … … 2011

13 Isotopic Menu – “Low Mass” Wavelengths, nmLaser SpectroscopyCARIBU IIILSMethodRange > 100/s 30Zn Ga Ge* As Se Br* Kr* CS Rb CS Sr CS Y414.4 JYFL.. 102CS Zr … 102CS Nb CS Mo … 108 CS Tc Ru Rh Pd Ag … 110CS Cd … 120CS In CS Sn CS, RIMS N = 50 Refractory elements N = 82 MOT Collinear

14 Menu of Isotopes – “High Mass” Wavelengths, nmLaser SpectroscopyCARIBU IIILSMethodRange > 100/s 51Sb Te I Xe* … 146CS Cs CS Ba – 146,148CS La TRIUMFCS JYFLCS Pr Nd … 150RIS Pm? Sm RIS Eu RIS Gd RIS Tb RIS Dy … 165RIS Ho … 165RIS Er … 167RIS N = 82 MOT Collinear

15 Ion beam Line for Laser Spec Setup PDT 90  3/10 kV -5 kV Post Accel. 50 kV 15 kV 3 kV kV Charge X Fluor. Det. 9 ft Stable +10/3 kV Lens X/Y Defl.

16 Discussion Points Need 1+ charge state for “heavy” isotopes –Operate buncher with neon

17 Laser Spectroscopy of Refractory Elements Measured 96–102 Zr with yields > 500 s -1 CARIBU: 106 Zr ~ 1x10 4 s -1 N=60 shape transition for higher Z: Nb, Mo … -> 109 Mo, 112 Nb 101 Zr I = 3/2 Laser Spectroscopy of Cooled Zirconium Fission Fragments, P. Campbell et al., PRL 89, (2002) Charge radius vs. deformation:

18 Beta-Neutrino Correlation in the Decay of 6 He 6 He 6 Li t 1/2 =0.808 sec 100%  E 0 = MeV Johnson et al., Phys. Rev. (1963) Best experimental limit: a = ± Na

19 Thank You! 8 He Collaboration K. Bailey, R. J. Holt, R. V. F. Janssens, Z.-T. Lu, P.M., T. P. O'Connor, I. Sulai Physics Division, Argonne National Laboratory, USA M.-G. Saint Laurent, J.-Ch. Thomas, A.C.C. Villari, J.A. Alcantara-Nunez, R. Alvez-Conde, M. Dubois, C. Eleon, G. Gaubert, N. Lecesne GANIL, Caen, France G. W. F. Drake - University of Windsor, Windsor, Canada L.-B. Wang – Los Alamos National Laboratory, USA Argon Atom Trappers

20 Barium Ion Spectroscopy for EXO With He as buffer gas and repumping EXO Collaboration

21 Collinear Laser Spectroscopy Well adapted to on-line mass separators Reduction of Doppler width: -> high resolution, high efficiency Need >1000 ions/s for “good cases” with fluorescence detection Higher efficiency with ion detection or decay counting Charge exchange: neutral atoms + metastable states Ion beam ~ 50 keV HV

22 Barium Quench Rate PRA 41, 2621 (1990)

23 GFMC – Binding Energy vs. Charge Radius

24 Atomic Energy Levels of Helium 2 3 S S eV 389 nm 1.2 eV 1083 nm 2 3 P 0,1, eV, e-collision in discharge 3 3 P 0,1,2 He discharge metastable He energy level diagram

25 CARIBU Layout Cf-252 source 80 mCi -> 1Ci High-resolution mass separator  m/m > 1/20000 Gas catcher Charge breeder Low Energy Experiments RF Cooler & Buncher

26 Laser Cooling and Trapping Magneto-Optical Trap (MOT) Cooling: Temperature~ 1 mK,  avoid Doppler shift / width Long observation time: 100 ms Spatial confinement: trap size < 1 mm  single atom sensitivity Selectivity:  no isotopic / isobaric interference Technical challenges: Short lifetime, small samples (<10 6 atoms/s available) Low metastable population efficiency (~ one in ) Precision requirement (100 kHz = Doppler 4 cm/s )

27 GFMC – What happens to the  -core? AV18 + IL2 GFMC proton-proton distributions

Hf Collinear Laser Spectroscopy with Cold & Bunched Beams A. Nieminen et al., PRL 88, (2002) gate on ion bunch reduce ion energy spread increase S/N by ~ 10 2 Voltage, V

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30 Laser Spectroscopy in Linear Paul Trap

31 Laser Spectroscopy of Hf in Spherical Paul Trap W.Z. Zhao et al., Hyperf.Int.108,483 (1997) H 2 buffer gas RF syncronized excitation and detection -> 1 GHz resolution 340 nm