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Searches for Lorentz violation in 3 He/ 129 Xe clock comparison experiments Outline: Features of frequency standards and clocks 3 He/ 129 Xe „spin“-clock Conclusion and outlook 3 He/ 129 Xe clock-comparison experiments W.Heil SSP2012, Groningen
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Current accuracy: Microwave: 6 x 10 -16 Optical : 3 x10 -17 Stable frequency Local oscillator sensitivity (absolute scale): mHz 1 ns / day „nuclear spin -clock“ better: reference transition at f 1 Hz with f /f 10 -14 1 second = 9,192, 631,770 cycles
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detector Clock based on nuclear spin precession „ spin-clock“ (ms ) signal (a.u.) (G. D. Cates, et al., Phys. Rev. A 37, 2877)
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Spin-clock: Detection of free spin precession : long spin coherence times T 2 * > 1 day @ f/f ~ 10 -14 free spin precession: no induced frequency shifts due to feedback phase error, light shift, etc. (Maser, Cs-M ) use of LT c -SQUIDs to detect the spin precession signal - intrinsic noise of SQUID: 1 fT/ Hz no feedback coupling between detector and spin sample
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Accuracy of frequency determination: # data points Fourier width If the noise w[n] is Gaussian distributed, the Cramer-Rao Lower Bound (CRLB) sets the lower limit on the variance example: SNR = 10000:1, = 1 Hz, T= 1 day < > x 0.1 m /day D=10 cm T
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n = -1.913 K He = -2.1276 K J Xe 129 He 3 Xe = -0.7779 K 3 He/ 129 Xe „spin“-clock OP-techniques: MEOP SEOP Schmidt-model:
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BMSR 2, PTB Berlin 6 cm 3 He (4.5 mbar ) J. Bork, et al., Proc. Biomag 2000, 970 (2000). The 7-layered magnetically shielded room (residual field < 2 nT) LT c - SQUID magnetic guiding field 0.4 T (Helmholtz-coils)
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3 He free spin-precession signal R d SQUID parameters: p He = 1-3 mbar ; P = 10-50% R =2.9 cm; d = 6cm B = 10-30 pT Signal: Note: At present, the Xe spin coherence time T 2 * is limited to due to wall relaxation 3 h < T 2 * < 4 h system noise inside BMSR-2 ~ 2 fT/ Hz
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Test of CRLB via Allan Standard Deviation (ASD) Non-gaussian noise: magnetic field drifts intrinsic noise … 2 [s] ii+1
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B [nT] t [h] 406.68 406.67 406.66 drift ~ 1pT/h 3 He / 129 Xe clock comparison to get rid of magnetic field drifts 129 Xe 3 He (4,7 Hz) (13 Hz) ! 10 -5 Hz/h B0B0
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I. Earth‘s rotation II. = He - He / Xe Xe rem = - Earth rem Subtraction of deterministic phase shifts uncertainties in subtraction of Earth chemical shift: BoBo non-ideal spherical cell: Ramsey-Bloch-Siegert shift (self shift) Phase residuals + (t) spin-coupling
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ASD of phase residuals
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The detection of the free precession of co-located 3 He/ 129 Xe sample spins can be used as ultra-sensitive probe for non-magnetic spin interactions of type: Search for a Lorentz violating sidereal modulation of the Larmor frequency Search for spin-dependent short-range interactions Search for EDM of Xenon … Observable:
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Search for a Lorentz violating sidereal modulation preferred direction in space-time
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SM: relativistic quantum field theory electromagnetic force weak force strong force gravitation General relativity is a classical theory, i.e., non-quantum Standard Model (SM) of particle physics Unification theories: string theory, loop quantum gravity,.. Planck scale: energy scale where gravity meets quantum physics M p ~ 10 19 GeV Courtesy of C. Lämmerzahl A closer look…
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Kostelecký, Perry, Pot, Samuel ’89; ’90; ’91; ’95; '00 Spontaneous Lorentz symmetry breaking in string theory e.g. Lorentz vector field makes non zero vacuum expectation value low-energy world Planck scale 10 19 GeV Background fields (tensor fields) give preferred direction e.g. rest frame of CMB D. Colladay and V.A. Kostelecky, Phys. Rev. D 55, 6760 (1997); Phys.Rev. D 58, 116002 (1998) talk of Ralf Lehnert
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Michelson (1881,Potsdam) Michelson&Morley (1887,Cleveland) c( ) = c photon sector: Traditional tests of Lorentz symmetry & special relativity 19 independent parameters Li + - ions C.Novotny et al., PR A 80 (2009) 022107 ESR at GSI relativistic Doppler effect c(v) = c
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Test of constancy of c Kennedy,Thorndike 1932 Hils,Hall 1990 Braxmaier 2002 Wolf 2004 Herrmann 2009 Resonators Interferometers Year
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Topics: searches for CPT and Lorentz violations involving -birefringence and dispersion from cosmological sources -clock-comparison measurements -CMB polarization -collider experiments -electromagnetic resonant cavities -equivalence principle -gauge and Higgs particles -high-energy astrophysical observations -laboratory and gravimetric tests of gravity -matter interferometry -neutrino oscillations -oscillations and decays of K, B, D mesons -particle-antiparticle comparisons -space-based missions -spectroscopy of hydrogen and antihydrogen -spin-polarized matter * Theoretical studies of CPT and Lorentz biviolation involving -physical effects at the level of the SM, General Relativity, and beyond -origins and mechanisms for violations classical and quantum issues in field theory, particle physics, gravity, and strings Modern Tests of Lorentz violation
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Modified Dirac equation for a free spin ½ particle (w=e,p,n) standard DECPT violatingCPT preserving terms A. Kostelecky and C. Lane: Phys. Rev. D 60, 116010 (1999) Lorentz violating terms Standard-Model Extension Experimental access: Cs- fountain Torsion pendulum Antihydrogen spectroscopy Astrophysics Hg/Cs comparison UCN/Hg comparison He/Xe maser K/He co-magnetometer coupling strength clock comparison experiments Wolf et al., B.Heckel et al. PRD 78 (2008) 092006 - matter sector -
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C Coupling of spin to background field: Zeeman LV LAB cosmic microwave background v = 368 km/s T dip 3.3 mK
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Search for a sidereal modulation of the weighted phase difference rem rem = He - He / Xe Xe - Earth s = 2 /T SD = 2 /(23 h :56 m :4.091 s ). expect strong correlated error for total data-taking time: 90 h March 2009 run:
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Results of 2 -fit for the sidereal phase amplitudes a c and a s together with their correlated and uncorrelated 1 -errors. a c mrad a s mrad -0.8820.8140.015-2.0671.0570.019 To demonstrate the strong dependence of the correlated error on s, corresponding fit results are shown for multiples of s : ’ s = g s. -0.0480.1200.016-0.1490.1120.017 -0.1840.0520.019-0.0110.0430.016 -0.0010.0340.0180.0570.0300.016 Phase residuals with fit-results for Phaseamplitude of the sidereal modulation:
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Kostelecky et al., Phys. Rev. D 60, 116010 (1999) 3 He: µ = -2.1276 µ K 129 Xe: µ = -0.7779 µ K n : µ = -1.913 µ K Schmidt-Model free neutron: (X,Y,Z) non-rotating frame with Z along Earth‘s rotation axis Lab-frame with quantization axis z In terms of frequency: (95% C.L.) PTB Berlin: = 52,5164 0 north = 28 0 (north-south) PRD 82 (2010) 111901
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Coefficient Proton Neutron Electron < 10 -32 < 10 -31 < 10 -32 < 10 -31 Torsion pendulum B.R.Heckel et al., PRD 78 (2008) 092006 K- 3 He co-magnetometer J. M. Brown et al. Phys. Rev. Lett., 105, 151604 (2010). Spin maser experiments with 3 He and 129 Xe ( D.Bear et al., PRL 85 (2000) 5038 ) (95% C.L.) = e Tightest constrains on SME parameters on neutron sector: our result:
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March 2012 run at PTB (1) conventional runs with B-field fixed (2) active rotation of B-field (2 h / turn)
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T 2 * - improvements: FID-Amplitude ( fT ) pure 3 He @ p=2.5 mbar : Gas mixture: p He = 2.7 mbar, p Xe = 4.9 mbar, p N2 = 24.8 mbar
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Phase residuals: March 2009 subrun for comparison (shifted by 0.04 rad) gain in SNR: 2-3 gain due to CRLB power law (~1/T 3/2 ) : 2.8 reduction of correlated error: ~ 7 total data taking time: 165 h (90 h March 2009 ) ~1.8 overall gain in sensitivity: ~ 100
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(2) rotation of B-field (quantization axis) 5 subruns (~ 14 h each) BMSR-2 N S expected LV-signal: … field rotation (45 0 ) : 2.5 min measurement (static): 12.5 min … Sequence:
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Change of the absolute field gradient during rotation and its effect on T 2 * data analysis ongoing
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Conclusion and Outlook 3 He, 129 Xe spin clock based on free spin precession long spin coherence times (, March 2012 run ) Search for neutron spin coupling to a Lorentz and CPT-violating background field K- 3 He and 3 He/ 129 Xe co-magnetometer set the tightest limits on SME-parameters K- 3 He co-magnetometer : 3 He- 129 Xe co-magnetometer : PRL 105, 151604 (2010) PRD 82, 111901 (2010) March 2012 run: expected gain in sensitivity ~ 100 to trace LV interactions
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Short range spin-dependent interaction: J.E.Moody, F.Wilczek PRD 30 (1984) 130 September 2010 run 129 Xe electric dipole moment (Groningen-Heidelberg-Mainz collaboration): Proposal: present sensitivity of 3 He/ 129 Xe-comagnetometer: < 0.1 nHz per day Rosenberry and Chupp, PRL 86,22 (2001) ecm Magnetometry ( 3 He)magnetometer for nEDM experiment at PSI high field : > 1 Tesla low field : 1 Tesla 1 3 57 beat signal (a.u.) time (s) @ 1.5 T ultra-high sensitive magnetometer to monitor relative field changes of 10 -12
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Institut für Physik, Universität Mainz: C. Gemmel, W. Heil, H.Hofsetz, S. Karpuk, Y. Sobolev, K. T. Physikalisch-Technische-Bundesanstalt, Berlin: M. Burghoff, W. Kilian, S. Knappe-Grüneberg, W. Müller, A. Schnabel, F. Seifert, L. Trahms Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg: F. Allendinger, U. Schmidt 3 He/ 129 Xe clock comparison probing fundamental symmetries K.Tullney Thank you for your attention
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Search for a new pseudoscalar boson (Axion-like particle) Original proposal for Axion ( R. Peccei, H.Quinn PRL 38(1977),1440) as possible solution to the „Strong CP Problem“ that cancels the CP violating term in the QCD Lagrangian from neutron EDM we get : Modern interest: Dark Matter candidate. All couplings to matter are weak Axions, if they exist, will be very light and will mediate a macroscopic CP- force energy scale P.Q.-symmetry is spontaneously broken Gerardus 't Hooft,: QCD has a non-trivial vacuum structure that in Gerardus 't Hooft principle permits CP-violation
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Galactic axions Tunable resonant cavity in magnetic field coupled to a ultra low noise microwave receiver ADMX, CARRACK 8 Tesla Axions generated in the sun Laboratory axions Polarised laser through vacuum in a strong magnetic field (PVLAS) AXION SEARCHES using the Primakoff Effect ** ** 1GHz: 4 eV E a 4 KeV “Light shines through the wall”
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If axions are dark matter, they are a relic of the early universe. A particular scenario coupled with the requirement that the axion mass density not severely overclose the universe results in a lower bound to the axion mass. CAST Current Axion Search Experiments Solar Axion Telescope – „CAST“ Dark Matter Axion Search – „ADMX“ Vacuum Optical Properties –“PVLAS“ etc. Photon Disappearance Experiments New Force Search – Torsion Pendulums, etc.
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Short range interaction of the axion (Moody and Wilczek PRD 30 130 (1984)) Yukawa-type potential with monopole-dipole coupling: axion gsgs gpgp N N nn nn F axion polarized matter unpolarized matter N n N
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How to measure? 3 He Position: Close unpolarized matter (Pb-glass, BGO) 3 He Position: Far Requirement:
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3 He/ 129 Xe cell Pb-glass (2009 run) BGO crystal (2010 run) Dewar housing the LT c -SQUIDs
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Data processing for extraction of short-range interaction effect: 1.To cancel magnetic field influence we calculate the weighted phase difference: 2. Temporal dependence can be described by: CloseFar t0t0 Earth rotation chemical shift short range Ramsey-Bloch-Siegert-Shift f(t)= c+(a ER +a CS +a SR ) t+a He e -t/T2,He +a Xe e -t/T2,Xe SR =(a SR,close - a SR,far ) He Xe 1 -1 -
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Results Analysis: Average potential was calculated numerically for our cells ( Ø = 6 cm, l = 6 cm), a gap of 2.2 mm between cell inner volume and BGO crystal ( Ø = 57 mm, l = 81 mm). Due to the inequation /h < Δ( ) the sensitivity level of g S g P can be determined by: g S g P ) B0B0 September 2010: 11 measurements (~9 hours) gap = 2.2 mm Mass sample: BGO crystal with density ρ=7.13 g/cm³ => SR = (-0.78 ± 1.22 ± 0.15) nHz SR [nHz] corr. [nHz] uncorr. [nHz] C53-R25.176.190.68 C54-R-7.394.280.56 C55-L-1.874.630.52 C60-L15.195.190.57 C63-L2.343.400.44 C65-L1.104.260.54 C67-R-3.824.090.53 C68-R-7.463.390.43 C71-R8.043.090.40 C80-L18.353.950.51 C82-L-22.004.430.56 LR
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Exclusion Plot for new spin-dependent forces Adelberger 2011 our result 2010 our result 2009 Youdin 1996 Ni 1999 Hammond 1993 gap of 0.5 mm
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Search for a Xe EDM I I I 129 Xe Xe EDM search short range int. CKM-C ̷ P too small to produce observed baryon asymmetry Standard-model: P,T transformation of spin and EDM
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particle EDM hadron EDM nuclear EDM atomic EDM observable EDM 10 -24
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3 10 -26 1.0 10 -27
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Atomic EDM‘s L.I.Schiff ( PR 132 2194,1963): System of non-relativistic charged point particles that interact electrostatically can not have an EDM Heavy atoms (relativistic treatment): d e 0 d atom 0 ~ Z 3 2 d e P,T-odd eN interaction Tensor-Pseudotensor ~Z 2 G F C T Scalar- Pseudoscalar ~Z 3 G F C S Nuclear EDM – finite size Schiff moment induced by P,T-odd N-N interaction ~10 -25 [ecm] Ginges & Flambaum, Phys. Rep. 397 (04) 63. Dzuba, Flambaum, Ginges, Phys. Rev. A 66 (02) 012111. Diamagnetic atoms: [ecm] Parameter 199 HgBest alternate limit d e (e cm) 3.0 10 -27 YbF:1.0 10 -27 d n (e cm) 5.8 10 -26 n: 2.9 10 -26 CSCS 5.2 10 -8 Tl:2.4 10 -7 CTCT 1.5 10 -9 TlF:4.5 10 -7 C PS 5.1 10 -7 TiF: 3 10 -4 8.0 10 -5 Xe: 5 10 -2 6 less sensitive to CP violating interactions E ext E int - ++ E ext +E int =0 PRL 102, 101601 (2009)
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Measurement sensitivity: 129 Xe electric dipole moment EoEo E E BoBo E E Then we will reach … after 100 days of data taking: from 2010 run: = 0.2 nHz @ 1 day assume : E=2 kV/cm Observable: weighted frequency difference sensitivity limit: Rosenberry and Chupp, PRL 86,22 (2001) ecm
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80 396 80 129Xe/3He polarizer Dewar with SQUIDs 5 layer -metal shield eddy current shield 3D field compensation University of Mainz KVI Groningen University of Heidelberg PTB Berlin Collaboration: Proposed setup Lorentz-invariance tests short range interations There is room for improvements: Increase of SNR of Xe (P xe : 10% 70%) Increase of T 2,Xe 5h (at present) 10-20 h d Xe < 10 -31 ecm …new sensitivity levels for
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Optical Pumping LASER absorption … …reemission of fluorescence light …transfer of angular momentum Rb-pumping 5 s 1/2 5 p 1/2 2/3 1/3 m = -1/2m = +1/2 T1T1 P = N( 1/2 ) – N( -1/2 ) N( 1/2 ) + N( -1/2 ) = 1 – (2/3) n rate equation: ++ BoBo
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Optical Pumping of 3 He history : ● Spin exchange with optically pumped Rb-vapour ( SEOP ) ( Bouchiat et al., Phys. Rev. Lett. 5 (1960) 373 ) ● Optical pumping of metastable 3 He * -atoms ( MEOP ) ( Colegrove et al., Phys. Rev. 132 (1963) 2561 ) Rb 3 He p He 1 mbar p He 1-10 bar 3 He * 3 He 3 He *
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MEOP: Metastabilty Exchange Optical Pumping 3 He * 1ppm L.D. Schearer 3 He : 1 mbar
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Kostelecky et al., Phys. Rev. D 60, 116010 (1999) 3 He: µ = -2.1276 µ K 129 Xe: µ = -0.7779 µ K n : µ = -1.913 µ K Schmidt-Model free neutron: (X,Y,Z) non-rotating frame with Z along Earth‘s rotation axis Lab-frame with quantization axis z In terms of frequency: (95% C.L.) PTB Berlin: = 52,5164 0 north = 28 0 (north-south)
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Feedback loop to get long coherence times … ( Cs-Magnetometer, Maser, … ) but … frequency shifts due to feedback phase error light shift …
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TSR (HD) : ß = 0.064 ESR(GSI) : ß = 0.34 Ch.D.Lane, PRD 72 (2005) 016005 β (moving clock) Laser P Laser A metastable 7 Li + - ions Lamb dip
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Clock-comparison experiments Kostelecky et al., arXiv:0801.0287v2
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Antihydrogen Spectroscopy ( J. Walz ) Torsion pendulum B.R.Heckel et al., PRD 78 (2008) 092006 spin-coupled interactions
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Fundamental physics tests using Rb and Cs fountains Observable free of 1st order Zeeman-effect Wolf et al.,
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: Earth‘s rotation frequency : Earth‘s orbital motion
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Relaxation of 129 Xe (measured)
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Magnetic field (measured via the He spin precession signal ) in presence of a conductor ( aluminium cylinder : diameter 56 mm, length 70 mm) removal of aluminium block Johnson noise paramagnetic effects
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(l, b) = (264 o.31±0 o.04±0 o.16, +48 o.05±0 o.02±0 o.09) galactic coordinate system horizon coordinate system (observer's local horizon) PTB-Berlin (52° 31´ north, 13° 25´ east) measurement on 01.10.2007 at CMB dipole v = 368 km/s T dip 3.3 mK
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Prototype of cylindrical -metal shield no elevated system noise inside inner shield made out of metglas (amorphous metal alloy ribbon)
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Lead glass samples Ø 57 mm H = 81 mm Density = 3.9 g/cm 3
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1083 nm MEOP Polarizer Mainz: 3 He SEOP Polarizer PTB: Xe He Xe N2N2
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(Cohen-Tannoudji et al., PRL 22 (1969),758) Detection of magnetic field produced by oriented nuclei Results: 3 He spin precession: T 2 * = 2h 20min sensitivity of Rb-magnetometer: 100fT@ BW 0.3 Hz P He 5% @ 4 mbar Improvement of measurement sensitivity: SQUID-detectors@2 fT/ Hz laser for OP of 3 He @ P> 70% longer T 2 *-times (needed !!!) 10 -11 tesla 10 -13 tesla
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False effects : Barometric formula : assume: S He S Xe x x h B0B0 = ½ ( Δ right sample - Δ left sample ) = (4.8 ± 7.0 ± 0.4) nHz drops out in From the measured value of we get: g S g P )
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1 day Gain in sensitivity compared to measurements with short coherence times: Example „short spin coherence time“: T = 5 min 300 less sensitive ! arbitrary phase
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