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Laser Laboratory (-ies). Peter Müller. Oven: 225 Ra (+Ba). Transverse cooling. Zeeman Slower. EDM probe. Optical dipole trap. Search for EDM of 225 Ra. Advantages: Large enhancement: EDM(Ra) / EDM(Hg) ~ 200 – 2000 Efficient use of 225 Ra atoms
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Laser Laboratory (-ies) Peter Müller
Oven: 225Ra (+Ba) Transverse cooling Zeeman Slower EDM probe Optical dipole trap Search for EDM of 225Ra • Advantages: • Large enhancement: • EDM(Ra) / EDM(Hg) ~ 200 – 2000 • Efficient use of 225Ra atoms • High electric field (> 100 kV/cm) • Long coherence times (~ 100 s) • Negligible “v x E” systematic effect
Search forEDM of 225Ra ~ 1x104 226Ra atoms 2 mm gap > 100 kV/cm • Status: • Trapped 225Ra and 226Ra • EDM probing region constructed • 10-10 Torr, 100 kV/cm, 10 mG • Next steps: • Dipole trap transfer • Optical pumping and detection
81Kr / 39Ar Atom Trap Trace Analysis • Krypton-81 : • cosmogenic • half-life = 230 ka • 81Kr/Kr = 1 x 10-12 • Argon-39 : • cosmogenic • half-life = 270 a • 39Ar/Ar = 8 x 10-16 • Dark Matter Searches : • LAr detectors (WARP, DEAP/CLEAN) • 39Ar major background • search for old / depleted Argon • Radio-Argon Dating : • 50 – 1000 year range • study ocean and groundwater • previously with LLC and AMS WIMP Argon Programme
Atom Trapping & Nuclear Charge Radii of 6,8He Atom Trap Setup 389 nm 1083 nm 8He Spectroscopy Singleatomsignal He-6: L.-B. Wang et al., PRL 93, 142501 (2004)He-8: P. Mueller et al., PRL 99, 252501 (2007)
Simulated time-of-flight signal New Physics Standard Model Beta-Decay Study with Laser Trapped 6He • 6He trapping rate: 1104 s-1, • 2105 coincidence events in 15 min: da = ± 0.008 • 1 week: da/a = 0.1% • 6He yields: • ATLAS: 1107 s-1 • CENPA: ~1109 s-1 • SARAF / SPIRAL2: ~11012 s-1
t1/2=0.808 sec 0+ 6He b- E0=3.5097 MeV 1+ 100% 6Li Beta-Neutrino Correlation in the Decay of 6He Best experimental limit: a = - 0.3343 ± 0.0030 21Na Johnson et al., Phys. Rev. (1963)
He-6 Production @ CENPA < 18 MeV ~ 5 pmA 2H
Isotopic Menu for Laser Spectroscopy Low-energyyield, s-1 > 106 105 - 106 104 - 105 103 - 104 102 - 103 10 - 102 1 - 10 < 1 • Isotope shifts -> charge radii, deformations • Hyperfine structure -> moments (dipole,…) -> spin
AC Laser Enclosure (~ 6’ x 10’) HEPA Laser Table (~ 3’ x 7’) Tape Station Ion Trap Collinear Beamline Laser Lab Layout @ CARIBU Cf-252 source 80 mCi -> 1Ci Gas catcher High-resolution mass separator dm/m > 1/20000 RF Cooler & Buncher … starting in fall 2010
PMT / EMCCD Linear Paul Trap for Spectroscopy black, conductively coated electrodes ITO coated optics Ba+ • open geometry, linear Paul trap -> large light collection efficiency • buffer gas w. LN2 cooling, -> good spectroscopic resolution, quenching of dark states • -> few (single ?) ion detection sensitivity
Ba Isotopes 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 detectionsystem • Buffer gas cooling + quenching (with H2) • Cooling of trap with LN2 Future: • other CARIBU beams • High mass: Pr, Nd, Eu, … • Low mass: Y, Zr, Nb, Sr, … • Yb+ -> No+ with ATLAS Upgrade
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
Isotopic Menu – “Low Mass” MOT Collinear N = 50 Refractoryelements N = 82
Menu of Isotopes – “High Mass” MOT Collinear N = 82
Ion Beam Line for Laser Spec Setup StableSource@ +10/3 kV + 2.9 kV Fluor. Det. 50 kV X/Y Defl. Charge X Lens 90 90 PDT 3 kV StableSource@ 3 kV 3/10 kV -5 kV PostAccel. 15 kV 9 ft
Discussion Points • Need 1+ charge state for “heavy” isotopes • Operate RF cooler & buncher with neon ? • Charge exchange 2+ to 1+ (???) on gas target • Beam energies, extraction voltage etc. • Location and type of stable beam sources • Gas catcher after gas filled separator • Where to put it to have “low energy beams” area? • For heavy elements or, e.g., Sn-100