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Atom Trap, Krypton-81, and Saharan Water
Western Desert, EgyptMay, 2002
• 81Kr dating
• Earlier Methods
• Atom Trap Trace Analysis (ATTA)
• Nubian Aquifer, Egypt
Supported by DOE, Office of Nuclear Physics NSF, Earth Science Division
• Widely applied
• Limited to 50 kyr or younger
14N
14C14CO2
14CO
Cosmicneutrons
Radio-Carbon DatingRadio-Carbon Dating
Willard Frank LibbyUniversity of Chicago
1960 Nobel Prize in ChemistryArnold&Libby, Science 110, 678 (1949)
14C (t1/2 = 5730yr, I.A.= 110-12)
• Polar Ice as a natural archive temperature precipitation gas composition volcanic eruption solar variability...
• Number of 81Kr atoms in 1 liter of : Air 20,000 Water 1,000 Ice 1,000
83Kr, 82Kr...
81Kr
Cosmicp, n
81Kr
Radio-Krypton DatingRadio-Krypton Dating81Kr ((t1/2 = 230kyr, I.A.= 610-13)
Low-Level Decay Counting Low-Level Decay Counting (LLC)(LLC)
83 10Count Time 100 hr
EfficiencyLifetime 330 kyr
81Kr (230 kyr) activity: 0.1 dpm/l Kr 85Kr (10.7 yr) activity: 3104 dpm/l Kr
X-ray @ 13.5 keV2 liters of krypton, 100 hours
Loosli and OeschgerEPSL 7, 67 (1969)
Proportionalcounter
Low-levellead
8585Kr in the AtmosphereKr in the Atmosphere
• Nuclear non-proliferation – Monitor fuel re-processing activities;• Nuclear safety – Monitor leaks from nuclear fuel containers.
F. Von Hippel, D.H. Albright, B.G. Levi, Scientific American 253, 40 (Sept., 1985)
(t1/2 = 11 yr, I.A.= 110-11)
Charge and mass measurements• Particle identification based on energy loss• Stripping eliminates molecular isobars• Negative ion tricks eliminates atomic isobars
Accelerator Mass Spectrometry Accelerator Mass Spectrometry (AMS)(AMS)
14N vs. 14C
R.A. Muller, Science 196, 489 (1977)D.E. Nelson et al., Science 198, 507 (1977)C.L. Bennett et al., Science 198, 508 (1977)
R.A. Muller, Physics Today Advantages of atom counting:• Fast, Sensitive; AMS / LLC = 105 (14C)• Not bothered by decay background
- -
National Superconducting Cyclotron LaboratoryMichigan State University
Full stripping at high energy (~ 4 GeV) for isobar separation: 81Kr36+ vs. 81Br35+.
Accelerator Mass Spectrometry of Kr-81Accelerator Mass Spectrometry of Kr-81W. Kutschera et al., NIM B29, 241 (1994); P. Collon et al., NIM B123, 122 (1997)
Laser Methods Based on Isotope ShiftsLaser Methods Based on Isotope Shifts
1s5--2p9 811nm Laser Frequency (MHz)0-713-997 -130 87
82 84 86 Kr-81 83 8580Kr-78Isotope shift due to the change in nuclear mass, charge radii and moments
12
10
8
6
4
2
0Ph
oto
n S
catte
rin
g R
ate
(re
l.)
-150 -100 -50 0 50 100 150
Laser Frequency (MHz)
Kr-81 Kr-83 Kr-85Hypothetical
10-16
10-14
10-12
10-10
10-8
10-6
10-4
10-2
100
Ph
oto
n S
catte
rin
g R
ate
(re
l.)
-150 -100 -50 0 50 100 150
Laser Frequency (MHz)
Kr-83
Kr-81Kr-85
Reality
Resonance Ionization Spectroscopy Resonance Ionization Spectroscopy (RIS)(RIS)
116 nm
558 nm
1064 nm
4p6
4p55s
4p56p
Kr
81Kr: Efficiency: >50% Isotope Selectivity: 103-104
S.D. Kramer et al., Nucl. Instr. Meth. B17, 395(1986)
V.S. Letokhov (Russia), G.S. Hurst (ORNL) 1970’s
10-16
10-14
10-12
10-10
10-8
10-6
10-4
10-2
100
Ph
oto
n S
ca
tte
rin
g R
ate
(re
l.)
-150 -100 -50 0 50 100 150
Laser Frequency (MHz)
Kr-83
Kr-81Kr-85
Photon Burst SpectroscopyPhoton Burst Spectroscopy
10-25
10-20
10-15
10-10
10-5
Ph
oto
n S
ca
tte
rin
g R
ate
(re
l.)
-150 -100 -50 0 50 100 150
Laser Frequency (MHz)
Kr-81Kr-83
Kr-85
One-photon probability
Four-photon probability
G.W. Greenlees et al., Opt. Commun. 23, 236 (1977); V.I. Balykin et al., JETP Lett. 26, 357 (1977)
Magneto-Optical Trap (MOT)Magneto-Optical Trap (MOT)
MOT Advantages• Long observation time -- 100 ms;
• High capture rate -- 109-1012 s-1;
• Narrow linewidth -- Doppler broadening negligible;
• Spatial confinement -- trap size < 1 mm;
• Storage -- separation of loading and detection.
E.L. Raab, M. Prentiss, A. Cable, S. Chu and D. Pritchard, Phys. Rev. Lett. 59, 2631 (1987)
Atom Trappers at Argonne
Krypton Atom Level DiagramKrypton Atom Level Diagram
5p[5/2]3
5s[3/2]2
4p6Ground-level
Metastable 40 sec
811 nm
10 eVelectron collision
0.0 0.5 1.0 1.5 2.0 2.5
0
5
10
15
20
25
Background
One Atom 81Kr
Photon S
cattering R
ate (
kH
z)
Time (sec)
<Single atom signal> = 1600 counts<Background> = 340 30 counts
0 1 2 3 4 5
0
5
10
15
2081
Kr
Photo
n S
catt
. R
ate
(kH
z)
Time (min.)
0 5 10 15 20 25
0
5
10
15
20
25
One Atom
Background
83Kr
Flu
orescence (
kH
z)
Time (sec)
Single Atom DetectionSingle Atom Detection
-1000 -800 -600 -400 -200 0 2000.0
0.1
0.2
0.3
84Kr
81Kr85Kr
86Kr82Kr
78Kr
80Kr83Kr
T
rap F
luo. (arb. unit)
0.0
0.2
0.4
0.6
0.8
1.0
83Kr
Trap F
luo.(
arb. units)
-150 -120 -90 -60 -30 0 30 60 90
05
101520253035
(0.5 hrs.)
85Kr
81Kr (3 hrs.)
Atom
Counts
Frequency Offset (MHz)
Counting Counting 8181Kr and Kr and 8585KrKr
Present Status of ATTA-2:
• Selectivity requirement: Done;
• Efficiency requirements: Practical, but far from perfection.
ATTA-1: C.Y. Chen et al., Science 286, 1139 (1999)
ATTA-2: X. Du et al., Geophys. Res. Lett. 30, 2068 (2003)
Atom Trap Trace Analysis (ATTA)Atom Trap Trace Analysis (ATTA)
10-8 10-7 10-6 10-5 10-4 10-3 10-2 10-1 1Efficiency
107 106 105 104 103 102 10 1
Water or IceSample Size (L)
Groundwater
Polar Ice
ATTA-11999
ATTA-22003
LLC1969
AMS1997
Calibration: ATTA vs. Low-Level CountingCalibration: ATTA vs. Low-Level CountingX. Du et al., Geophys. Res. Lett. 30, 2068 (2003)
ATTA at Argonne, LLC at Bern
8181Kr Abundance MeasurementsKr Abundance Measurements• Assumed identical trapping efficiency for 81Kr and 85Kr;• Need to calibrate ATTA efficiency with a 81Kr standard;• Atmospheric 81Kr is an integrator of cosmic-ray flux.
(6.46 0.72) 10-13, LLC, H.H. Loosli and H. Oeschger, Ear Plan Sci Lett 7, 67 (1969)(4.33 0.29) 10-13, LLC, V.V. Kuzminov & A.A. Pomanski, Radiocarbon 22, 311 (1980)(5.3 1.2) 10-13, AMS, P. Collon et al., NIM B123, 122 (1997)(10 4) 10-13, ATTA, C.-Y. Chen et al., Science 286, 1139 (1999)(11.0 0.5) 10-13, ATTA, X. Du et al., Geophys Rev Lett 30, 2068 (2003)(4.8 1.0) 10-13, Theory, J. Masarik, private communication (2003)
Nubian Aquifer
• Area ~ 2 x 106 km2
• Volume ~ 5 x 104 km3
• 500 years of Nile discharge
• Age ~ 105 years
First Applications: Nubian Aquifer, EgyptFirst Applications: Nubian Aquifer, Egypt
Expedition Team
Argonne National Laboratory: Z.-T. Lu, M. SultanUniversity of Bern: R. Purtschert, R. LorenzoUniversity of Illinois: N. Sturchio
Ain Shams University: A. El Bedawy, Y. Dawood, B. El Kaliouby, A. Mohammed Egyptian Geological Survey: Z. El Alfy, Radwan
Well
Outgassing
Work at night
Sheesha
Sand Dune
One Million Years of Nubian Aquifer Groundwater HistoryOne Million Years of Nubian Aquifer Groundwater History
33344 kyr
21242 kyr
39146 kyr
48845 kyr
67875 kyr
0.60.21.0 Myr
N. C. Sturchio et al., Geophys. Res. Lett. 31, 05503 (2004)
• Groundwater at six sites dated;• Flow direction and speed measured;• Source determined.
Uweinat Uplift
ATTA CoveredATTA Covered
8181Kr Dating: From Dream to PracticeKr Dating: From Dream to Practice
10-8 10-7 10-6 10-5 10-4 10-3 10-2 10-1 1Efficiency
107 106 105 104 103 102 10 1
Water or IceSample Size (L)
Groundwater
Polar Ice
LLC1969
AMS1997
ATTA-I1999
ATTA-II2003
ATTA-III?
Kr-ATTA version 3.0
Incremental improvements: Cool Kr* source to 100-200 K; More laser power; Fancier techniques.
Kr-ATTA version 4.0
Optical production of Kr* 124 nm + 819 nm L. Young et al., J. Phys. B 35 (2002) Kapteyn et al.
215 nm + 215 nm
5s[3/2]02
4p6
Ground
Metastable
5p[3/2]2
124 nm
5s[3/2]01
819 nm
215 nm
215 nm
ATTA-IV?
Halo Nucleus Halo Nucleus 66HeHe
Isotope Half-life Spin Isospin Core + Valence
He-6 807 ms 0+ 1 + 2n
Borromean Rings
Search for EDM of Search for EDM of 225225RaRaAdvantages of an EDM measurement on 225Ra atoms in a trap• In 225Ra the EDM effect is enhanced by ~102 due to nuclear deformation.• Trap allows a long coherence time (~ 300 s).• Cold atoms results in a negligible “v x E” systematic effect.• Trap allows the efficient use of the rare and radioactive 225Ra atoms.• Small sample in an UHV allows a high electric field (> 100 kV/cm).
225Ra
Nuclear Spin = ½
Electronic Spin = 0
t1/2 = 15 days
Proposed setupAtomic Beam
Magneto-OpticalTrap
TransverseCooling
Oven
10 mCi225Ra sample
CO2-Laser Optical Dipole Trap
EDM-probing region
Transition Requirements: Cycling transition High transition rate (107 sec-1, allowed E1) Practical wavelength ( > 200 nm)
Excite
DecayForbidden
48Cd
20Ca
1H
3Li
11Na
37Rb
55Cs
87Fr
4Be
12Mg
38Sr
56Ba
88Ra
21Sc
39Y
57La
89Ac
22Ti
40Zr
72Hf
104Rf
23V
41Nb
73Ta
105Db
24Cr
42Mo
74W
106Sg
25Mn
43Tc
75Re
107Bh
26Fe
44Ru
76Os
108Hs
27Co
45Rh
77Ir
109Mt
28Ni
46Pd
78Pt
110Uun
29Cu
47Ag
79Au
111Uuu
30Zn
80Hg
112Uub
5B
13Al
31Ga
49In
81Tl
6C
14Si
32Ge
50Sn
82Pb
114Uuq
7N
15P
33As
51Sb
83Bi
8O
16S
34Se
52Te
84Po
116Uuh
9F
17Cl
35Br
53I
85At
2He
10Ne
18Ar
36Kr
54Xe
86Rn
118Uuo
58Ce
90Th
59Pr
91Pa
60Nd
92U
61Pm
93Np
62Sm
94Pu
63Eu
95Am
64Gd
96Cm
65Tb
97Bk
66Dy
98Cf
67Ho
99Es
68Er
100Fm
69Tm
101Md
70Yb
102No
71Lu
103Lr
19K
36Kr Demonstrated
86Rn Trappable
Trappable AtomsTrappable Atoms
Applicable Age Ranges (~ 0.1-10 tApplicable Age Ranges (~ 0.1-10 t1/21/2) of Radionuclides) of Radionuclides
Age Range (year)
Tra
cers
100 101 102 103 104 105 106
14C
81Kr, 36Cl
39Ar
85Kr, 3H/3He
107
10Be
Noble gas tracers: advantages and disadvantages Simple production, transport, and deposition processes. Long residence time in atmosphere uniform and constant abundance. percentages in atmosphere: Ar, 99%; Kr, 97.5%; 14C, 2% Easy to extract from large environmental samples. Low concentration in samples. Extremely difficult to analyze.
A New Tool for Nuclear Physics Research and BeyondA New Tool for Nuclear Physics Research and Beyond
A tool for studying exotic nuclear structure
Determined the charge radius of the lightest halo nucleus 6He
A tool for testing time-reversal symmetry
Search for T-violating EDM in octupole deformed 225Ra
A tool for studying Earth climate history
Realized radio-krypton dating of old groundwater
A tool for nuclear safety and security
Monitor environmental 85Kr gas produced by nuclear fission
A tool for medical diagnostics
Monitor bone-loss rate with 41Ca
ATTA Analysis of ATTA Analysis of 4141Ca in Biomedical SamplesCa in Biomedical Samples
41Ca is an ideal tracer for
studying calcium
transport in bio-systems
and for measuring bone-
loss rates.GI tract
ECF Plasma
Soft tissue
Bone pools
Dietary calcium
UrineFeces
41Calabeled
I. D. Moore et al., Phys. Rev. Lett. 92, 153002 (2004)
• First demonstration of ATTA for 41Ca analysis;• Analyzed 41Ca/Ca ratios in biomedical samples.
2.12.01.91.81.7
Point-Proton Radius of 6He (fm)
Tanihata et al 92
Alkhazov et al 97
Csoto 93
Funada et al 94
Varga et al 94
Wurzer et al 97
Esbensen et al 97
Pieper&Wiringa 01 (AV18 + IL2)
This work 04
Navratil et al 01
(AV18 + UIX)
(AV18)
Reaction collision
Elastic collision
Atomic isotope shift
Cluster models
No-core shell model
Quantum MC
Exp
erim
ents
The
orie
s
A Proving Ground for Nuclear Structure TheoriesA Proving Ground for Nuclear Structure TheoriesL.-B. Wang et al., Phys. Rev. Lett. 93, 142501 (2004)
First model-independent determination
P. Collon et al., Earth Planet Sci. Lett. 182, 103 (2000)
Watson Creek (4.02 0.51) 105 yrOodnadatta (3.54 0.50) 105 yrDuck Hole (2.87 0.38) 105 yrRaspberry Creek (2.25 0.42) 105 yr
The Great Artesian Basin
First First 8181Kr-Dating of Old GroundwaterKr-Dating of Old Groundwater
16,000 litersof water
0.5 ccSTP Kr~ 2 106 81Kr
56 81Kr countsin 9 hours
Chemitry AMS
AMS Counting Efficiency ~ 3 10-5
8181Kr vs. Kr vs. 3636ClCl
0
50
100
150
0 500 1000 1500 200081Kr age (kyr)
36 C
l/Cl (
x 1
0-15 )
Bauti 1
Sherka 36
Baris(Aden)
El Zayat 12Farafra 6
Gum Horia
Systematic effect in 36Cl dating
• Variations in deposition rates
~ factor of 5
• Nucleogenic 36Cl 35Cl(n,)36Cl, = 44 barn
• Dissolved mineral Cl
N. C. Sturchio et al., Geophys. Res. Lett. 31, 05503 (2004)
Krypton ATTA SetupKrypton ATTA Setup
2.5 metersOne Yao long
