Spin-Exchange-Pumped NMR Gyros

Walker, Thad; Larsen, Michael

doi:10.1016/bs.aamop.2016.04.002

Cited by 164 publications

(106 citation statements)

References 38 publications

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“…Dx, 06.30.Gv, 39.90.+d Spin comagnetometers first introduced in [1] are used for several types of fundamental physics experiments, such as tests of Lorentz, CP and CPT symmetries [2][3][4][5] and searches for spin-dependent forces [6][7][8][9][10]. They also have practical applications as inertial rotation sensors [11][12][13][14][15][16]. When two different spin ensembles occupy the same volume they experience nearly the same average magnetic field [17].…”

mentioning

confidence: 99%

He3−Xe129 Comagnetometery using
Limes
¹
,
Sheng
²
,
Romalis
³

2018
Phys. Rev. Lett.
129
2
81
0
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We describe a 3 He-129 Xe comagnetometer using 87 Rb atoms for noble-gas spin polarization and detection. We use a train of 87 Rb π pulses and σ + /σ − optical pumping to realize a finite-field Rb magnetometer with suppression of spin-exchange relaxation. We suppress frequency shifts from polarized Rb by measuring the 3 He and 129 Xe spin precession frequencies in the dark, while applying π pulses along two directions to depolarize Rb atoms. The plane of the π pulses is rotated to suppress the Bloch-Siegert shifts for the nuclear spins. We measure the ratio of 3 He to 129 Xe spin precession frequencies with sufficient absolute accuracy to resolve the Earth's rotation without changing the orientation of the comagnetometer. A frequency resolution of 7 nHz is achieved after integration for 8 hours without evidence of significant drift.PACS numbers: 32.30. Dx, 06.30.Gv, 39.90.+d Spin comagnetometers first introduced in [1] are used for several types of fundamental physics experiments, such as tests of Lorentz, CP and CPT symmetries [2][3][4][5] and searches for spin-dependent forces [6][7][8][9][10]. They also have practical applications as inertial rotation sensors [11][12][13][14][15][16]. When two different spin ensembles occupy the same volume they experience nearly the same average magnetic field [17]. The ratio of their spin precession frequencies f r = ω He /ω Xe can then be used to measure the inertial rotation rate Ω or a spin coupling beyond the Standard Model b:( 1) where B 0 is the bias field alongẑ and γ He , γ Xe are the gyromagnetic ratios for 3 He and 129 Xe, which are well known [18]. Since I = 1/2 nuclear spins are free from quadrupolar energy shifts [19], f r provides an absolute measure of non-magnetic spin interactions-this is particularly important in searches for spin-gravity coupling [20] (where the interaction is hard to modulate), and for use as a gyroscope.An alkali-metal magnetometer provides a natural way to detect nuclear-spin signals because Rb atoms are already used to polarize the nuclear spins by spin-exchange collisions; these collisions enhance the classical dipolar field from the nuclear magnetization by a factor κ 0 [21], which is about 5 for Rb-3 He [22] and 500 for Rb-Xe [23]. However, the presence of polarized Rb atoms also causes large noble-gas frequency shifts that affect the accuracy of Eq. (1). In the past, these frequency shifts have been avoided in 3 He-129 Xe comagnetometers by detecting a smaller dipolar field outside of an alkali-free cell using an RF coil [24] or a SQUID magnetometer [25].In this Letter we describe a new method for operating the 3 He-129 Xe comagnetometer using 87 Rb readout with high sensitivity and accuracy. We develop a 87 Rb magnetometer that can operate in a finite magnetic field of about 5 mG while suppressing Rb-Rb spin-exchange relaxation to increase the magnetometer sensitivity. It

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mentioning

confidence: 99%

He3−Xe129 Comagnetometery using
Limes
¹
,
Sheng
²
,
Romalis
³

2018
Phys. Rev. Lett.
129
2
81
0
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“…Therefore, the frequency of the pulse-driven magnetic field should match the Larmor frequency of noble gases, as Larmor frequency partly depends on the value of B 0 and the shift caused by the spin-exchange interaction with alkali atoms. 23 …”

Section: Simulationmentioning

confidence: 99%

“…Taking into account the relaxation mechanism, 23 the spin dynamics of noble gases can be approximated by the Bloch Equation in the rotating frame 24 and be represented as the following,…”

mentioning

confidence: 99%

Effects of the pulse-driven magnetic field detuning on the calibration of coil constants while using noble gases

et al. 2018

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In the calibration of coil constants using the Free Induction Decay (FID) signal of noble gases, we analyse the effects of the pulse-driven magnetic field detuning on the calibration results. This method is based on the inverse relation between the π/2 pulse duration and its amplitude. We confirmed that obtaining a precise frequency is a prerequisite for ensuring the accuracy of research using the initial amplitude of the FID signal. In this paper, the spin dynamics of noble gases and its time-domain solution under the driving pulse have been discussed with regard to different detuning ranges. Experimental results are in good agreement with our theoretical predictions, which indicate the correctness of our theoretical deduction. Therefore, the frequency of the pulse-driven magnetic field is an important factor to the calibration of coil constants, it should be determined with a high degree of accuracy.

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“…Nuclear magnetic resonance gyros based on spin-exchange optical pumping of noble gases have been developed over several decades. 13,15 The basis for the NMR gyro is the stability of the Larmor precession frequency of the nuclear spin when nuclei are exposed to a constant magnetic field. A NMR gyro consists of a noble gases cell, two lasers, a three-dimensional magnetic field coil system, multilayer magnetic shields and other indispensable attachments.…”

Section: B Application Demonstration In a Miniature Nmr Gyromentioning

confidence: 99%

“…The theory and structure of NMR gyro are not the emphasised issues of this paper, and details of them can be found in many papers. 4,13,15 The optimized nested coil with a diameter of 25 mm is manufactured by FPC technology and glued on the surface of a frame. The Lee-Whiting coil is adopted to provide a sufficiently uniform longitudinal magnetic field for NMR gyro.…”

Section: B Application Demonstration In a Miniature Nmr Gyromentioning

confidence: 99%

Novel nested saddle coils used in miniature atomic sensors

Zhou

Liu

et al. 2018

AIP Advances

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A novel uniform magnetic field coil structure with two pairs of saddle coils nested is proposed in order to minish the aspect ratio without losing much field uniformity, which is significant in innovative miniature atomic instruments and sensors. Optimal configuration parameters are obtained from the Taylor expansion of the magnetic field. The remainder terms are used to estimate the field uniformity and optimize the configuration while minishing computation time. Compared with traditional saddle coils, the nested saddle coils have unique advantages in miniature applications where the aspect ratios are strictly limited. The optimized nested saddle coils were manufactured by Flexible Printed Circuit (FPC) technology and the magnetic field uniformities were verified experimentally using a flux-gate magnetometer. Furthermore, the example application of a miniature nuclear magnetic resonance (NMR) gyro demonstrates the practical use of the nested coils.

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Spin-Exchange-Pumped NMR Gyros

Cited by 164 publications

References 38 publications

He3−Xe129 Comagnetometery using
Limes
¹
,
Sheng
²
,
Romalis
³

2018
Phys. Rev. Lett.
129
2
81
0
View full text Add to dashboard Cite

He3−Xe129 Comagnetometery using
Limes
¹
,
Sheng
²
,
Romalis
³

2018
Phys. Rev. Lett.
129
2
81
0
View full text Add to dashboard Cite

Effects of the pulse-driven magnetic field detuning on the calibration of coil constants while using noble gases

Novel nested saddle coils used in miniature atomic sensors

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Spin-Exchange-Pumped NMR Gyros

Cited by 164 publications

References 38 publications

He3−Xe129 Comagnetometery using Limes1, Sheng2, Romalis3 2018Phys. Rev. Lett.1292810View full textAdd to dashboardCite

He3−Xe129 Comagnetometery using Limes1, Sheng2, Romalis3 2018Phys. Rev. Lett.1292810View full textAdd to dashboardCite

Effects of the pulse-driven magnetic field detuning on the calibration of coil constants while using noble gases

Novel nested saddle coils used in miniature atomic sensors

Contact Info

Product

Resources

About

He3−Xe129 Comagnetometery using
Limes
¹
,
Sheng
²
,
Romalis
³

2018
Phys. Rev. Lett.
129
2
81
0
View full text Add to dashboard Cite

He3−Xe129 Comagnetometery using
Limes
¹
,
Sheng
²
,
Romalis
³

2018
Phys. Rev. Lett.
129
2
81
0
View full text Add to dashboard Cite