Laser%20Laboratory%20(-ies)

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Laser Laboratory (-ies)

• Peter Müller

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Search for EDM of 225Ra

• Advantages
• Large enhancement
• EDM(Ra) / EDM(Hg) 200 2000
• Efficient use of 225Ra atoms
• High electric field (gt 100 kV/cm)
• Long coherence times ( 100 s)
• Negligible v x E systematic effect

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Search forEDM of 225Ra
1x104 226Ra atoms
2 mm gap gt 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

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81Kr / 39Ar Atom Trap Trace Analysis

• Argon-39
• cosmogenic
• half-life 270 a
• 39Ar/Ar 8 x 10-16

• Krypton-81
• cosmogenic
• half-life 230 ka
• 81Kr/Kr 1 x 10-12

• 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
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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)
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Beta-Decay Study with Laser Trapped 6He

• 6He trapping rate 1?104 s-1,
• 2?105 coincidence events in 15 min da
  0.008
• 1 week da/a 0.1

• 6He yields
• ATLAS 1?107 s-1
• CENPA 1?109 s-1
• SARAF / SPIRAL2 1?1012 s-1

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Isotopic Menu for Laser Spectroscopy
Low-energyyield, s-1 gt 106 105 - 106 104 -
105 103 - 104 102 - 103 10 - 102 1 - 10 lt 1

• Isotope shifts -gt charge radii, deformations
• Hyperfine structure -gt moments (dipole,)
  -gt spin

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Laser Lab Layout _at_ CARIBU
Cf-252 source 80 mCi -gt 1Ci
Gas catcher
High-resolution mass separator dm/m gt 1/20000
RF Cooler Buncher
starting in fall 2010
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Linear Paul Trap for Spectroscopy
black, conductive coated electrodes
ITO coated optics
Ba

• open geometry, linear Paul trap -gt large light
  collection efficiency
• buffer gas w. LN2 cooling, -gt good spectroscopic
  resolution, quenching of dark states
• -gt few (single ?) ion detection sensitivity

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Ion Trap Spectroscopy at CARIBU
Ba Isotopes

• 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 -gt No with ATLAS Upgrade

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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
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Isotopic Menu Low Mass
    Wavelengths, nm Wavelengths, nm Laser Spectroscopy Laser Spectroscopy CARIBU CARIBU
    I II LS Method Range gt 100/s Range gt 100/s
30 Zn 589.4       75 79
31 Ga 417.2       76 83
32 Ge 265.16       77 86
33 As 197.2       79 89
34 Se 207.48       80 92
35 Br 827.47       83 94
36 Kr 811.52   72 .. 96 CS 85 97
37 Rb 780.0   76 - 96 CS 87 97
38 Sr 460.86 421.7 77 - 100 CS 89 102
39 Y 414.4   JYFL .. 102 CS 91 104
40 Zr 388.65   87 102 CS 94 106
41 Nb 492.45    .. 103 CS 97 109
42 Mo 390.41   108  CS  100 112
43 Tc 429.82       101 113
44 Ru 392.7       103 115
45 Rh 369.34       105 118
46 Pd 276.39       109 124
47 Ag 328.16   101 110 CS 111 125
48 Cd 326.1 214.5 102 120 CS 112 126
49 In 451.3 236.5 104 - 127 CS 115 133
50 Sn 452.5   108 - 132 CS, RIMS 124 136
MOT Collinear
N 50
Refractoryelements
N 82
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Menu of Isotopes High Mass
MOT Collinear
    Wavelengths, nm Wavelengths, nm Laser Spectroscopy Laser Spectroscopy CARIBU CARIBU
    I II LS Method Range gt 100/s Range gt 100/s
51 Sb 231.22       124 138
52 Te 214.35       129 140
53 I 183.04       131 142
54 Xe 882.18   116 146 CS 133 146
55 Cs 455.65   118 - 146 CS 135 148
56 Ba 553.7 455.4 120 146,148 CS 137 150
57 La 418.84   _at_ TRIUMF CS 139 152
58 Ce 450.64 331 _at_ JYFL CS 141 155
59 Pr 495.14 590     144 157
60 Nd 468.34 590 132 150 RIS 146 159
61 Pm ?       149 161
62 Sm 471.71   138 - 154 RIS 151 164
63 Eu 459.4 604.9 138 - 159 RIS 154 166
64 Gd 432.71   146 - 160 RIS 156 168
65 Tb 432.64   147 ... 159 RIS 159 169
66 Dy 404.71   146 165 RIS 162 171
67 Ho 410.38   151 165 RIS 166 171
68 Er 415.23   150 167 RIS 169 172
N 82
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Ion beam Line for Laser Spec Setup
StableSource_at_ 10/3 kV
2.9 kV
Fluor. Det.
50 kV
X/Y Defl.
Charge X
Lens
PDT
3 kV
3/10 kV
90?
-5 kV PostAccel.
15 kV
9 ft
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Discussion Points

• Need 1 charge state for heavy isotopes
• Operate buncher with neon

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Laser Spectroscopy of Refractory Elements
Laser Spectroscopy of Cooled Zirconium Fission
Fragments, P. Campbell et al., PRL 89, 082501
(2002)
101Zr
I 3/2
Charge radius vs. deformation

• Measured 96102Zr with yields gt 500 s-1 -gt _at_
  CARIBU 106Zr 1x104 s-1
• N60 shape transition for higher Z Nb, Mo -gt
  109Mo, 112Nb

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Beta-Neutrino Correlation in the Decay of 6He
Best experimental limit a - 0.3343
0.0030
21Na
Johnson et al., Phys. Rev. (1963)
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Thank You!
8He CollaborationK. Bailey, R. J. Holt, R. V. F.
Janssens, Z.-T. Lu, P.M., T. P. O'Connor, I.
SulaiPhysics Division, Argonne National
Laboratory, USAM.-G. Saint Laurent, J.-Ch.
Thomas, A.C.C. Villari, J.A. Alcantara-Nunez, R.
Alvez-Conde, M. Dubois, C. Eleon, G. Gaubert, N.
LecesneGANIL, Caen, FranceG. W. F. Drake -
University of Windsor, Windsor, CanadaL.-B. Wang
Los Alamos National Laboratory, USA
Argon Atom Trappers
www.phy.anl.gov/mep/atta/
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Barium Ion Spectroscopy for EXO
EXO Collaboration
With He as buffer gas and repumping
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Collinear Laser Spectroscopy
Ion beam 50 keV
HV

• Well adapted to on-line mass separators
• Reduction of Doppler width -gt high resolution,
  high efficiency
• Need gt1000 ions/s for good cases with
  fluorescence detection
• Higher efficiency with ion detection or decay
  counting
• Charge exchange neutral atoms metastable
  states

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Barium Quench Rate
PRA 41, 2621 (1990)
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GFMC Binding Energy vs. Charge Radius
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Atomic Energy Levels of Helium
He energy level diagram
3 3P0,1,2
He discharge
3.2 eV389 nm
2 3P0,1,2
1.2 eV1083 nm
2 3S1
metastable
19.8 eV,e-collision in discharge
1 1S0
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CARIBU Layout
Cf-252 source 80 mCi -gt 1Ci
Gas catcher
High-resolution mass separator dm/m gt 1/20000
Low Energy Experiments
RF Cooler Buncher
Charge breeder
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Laser Cooling and Trapping

• Technical challenges
• Short lifetime, small samples (lt106 atoms/s
  available)
• Low metastable population efficiency ( one in
  100.000)
• Precision requirement (100 kHz Doppler shift _at_
  4 cm/s )

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GFMC What happens to the a-core?
AV18 IL2 GFMC proton-proton distributions
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Collinear Laser Spectroscopy with Cold Bunched
Beams
A. Nieminen et al., PRL 88, 094801 (2002)
174Hf
Voltage, V

• gate on ion bunch
• reduce ion energy spread
• increase S/N by 102

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Laser Spectroscopy in Linear Paul Trap
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Laser Spectroscopy of Hf in Spherical Paul Trap
340 nm

• H2 buffer gas
• RF syncronized excitation and detection -gt 1
  GHz resolution

W.Z. Zhao et al., Hyperf.Int.108,483 (1997)