skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: High-sensitivity operation of single-beam optically pumped magnetometer in a kHz frequency range

Abstract

Here, optically pumped magnetometers (OPM) can be used in various applications, from magnetoencephalography to magnetic resonance imaging and nuclear quadrupole resonance (NQR). OPMs provide high sensitivity and have the significant advantage of non-cryogenic operation. To date, many magnetometers have been demonstrated with sensitivity close to 1 fT, but most devices are not commercialized. Most recently, QuSpin developed a model of OPM that is low cost, high sensitivity, and convenient for users, which operates in a single-beam configuration. Here we developed a theory of single-beam (or parallel two-beam) magnetometers and showed that it is possible to achieve good sensitivity beyond their usual frequency range by tuning the magnetic field. Experimentally we have tested and optimized a QuSpin OPM for operation in the frequency range from DC to 1.7 kHz, and found that the performance was only slightly inferior despite the expected decrease due to deviation from the spin-exchange relaxation-free regime.

Authors:
ORCiD logo [1];  [1];  [2];  [1]
  1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  2. QuSpin Inc., Louisville, CO (United States)
Publication Date:
Research Org.:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Org.:
USDOE Laboratory Directed Research and Development (LDRD) Program
OSTI Identifier:
1344356
Report Number(s):
LA-UR-16-24444
Journal ID: ISSN 0957-0233; TRN: US1700892
Grant/Contract Number:
AC52-06NA25396
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Measurement Science and Technology
Additional Journal Information:
Journal Volume: 28; Journal Issue: 3; Journal ID: ISSN 0957-0233
Publisher:
IOP Publishing
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; Atomic and Nuclear Physics

Citation Formats

Savukov, Igor Mykhaylovich, Kim, Y. J., Shah, V., and Boshier, M. G.. High-sensitivity operation of single-beam optically pumped magnetometer in a kHz frequency range. United States: N. p., 2017. Web. doi:10.1088/1361-6501/aa58b4.
Savukov, Igor Mykhaylovich, Kim, Y. J., Shah, V., & Boshier, M. G.. High-sensitivity operation of single-beam optically pumped magnetometer in a kHz frequency range. United States. doi:10.1088/1361-6501/aa58b4.
Savukov, Igor Mykhaylovich, Kim, Y. J., Shah, V., and Boshier, M. G.. Thu . "High-sensitivity operation of single-beam optically pumped magnetometer in a kHz frequency range". United States. doi:10.1088/1361-6501/aa58b4. https://www.osti.gov/servlets/purl/1344356.
@article{osti_1344356,
title = {High-sensitivity operation of single-beam optically pumped magnetometer in a kHz frequency range},
author = {Savukov, Igor Mykhaylovich and Kim, Y. J. and Shah, V. and Boshier, M. G.},
abstractNote = {Here, optically pumped magnetometers (OPM) can be used in various applications, from magnetoencephalography to magnetic resonance imaging and nuclear quadrupole resonance (NQR). OPMs provide high sensitivity and have the significant advantage of non-cryogenic operation. To date, many magnetometers have been demonstrated with sensitivity close to 1 fT, but most devices are not commercialized. Most recently, QuSpin developed a model of OPM that is low cost, high sensitivity, and convenient for users, which operates in a single-beam configuration. Here we developed a theory of single-beam (or parallel two-beam) magnetometers and showed that it is possible to achieve good sensitivity beyond their usual frequency range by tuning the magnetic field. Experimentally we have tested and optimized a QuSpin OPM for operation in the frequency range from DC to 1.7 kHz, and found that the performance was only slightly inferior despite the expected decrease due to deviation from the spin-exchange relaxation-free regime.},
doi = {10.1088/1361-6501/aa58b4},
journal = {Measurement Science and Technology},
number = 3,
volume = 28,
place = {United States},
year = {Thu Feb 02 00:00:00 EST 2017},
month = {Thu Feb 02 00:00:00 EST 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 1work
Citation information provided by
Web of Science

Save / Share:
  • In a compact optically pumped atomic magnetometer (OPAM), there is a plateau in the sensitivity where the dependence of the sensitivity on pumping power is small compared with that predicted by the uniform polarization model. The mechanism that generates this plateau was explained by numerical analysis. The distribution of spin polarization in the alkali metal cell of an OPAM was modeled using the Bloch equation incorporating a diffusion term and an equation for the attenuation of the pump beam. The model was well-fitted to the experimental results for a module with a cubic cell with 20 mm sides and pumpmore » and probe beams with 8 mm diameter. On the plateau, strong magnetic response was generated at the regions that were not illuminated directly by the intense pump beam, while at the same time spin polarization as large as 0.5 was maintained due to diffusion of the spin-polarized atoms. Thus, the sensitivity of the magnetometer monitored with a probe beam decreases only slightly with increasing pump beam intensity because the spin polarization under an intense pump beam is saturated. This plateau, which is characteristic of this type of magnetometer using a narrow pump and probe beams, can be used in arrays of magnetometers because it enables stable operation with little sensitivity fluctuation from changes in pump beam power.« less
  • A Kr excimer laser pumped by a relativistic electron beam has generated high-power output by using a cavity composed of a Si mirror and MgF/sub 2/ mirror. The threshold gas pressure for laser oscillation is 10 atm, and the maximum output power achieved so far is 6.6 MW at 15 atm. The maximum power is limited by the surface damages on the mirrors. The laser output oscillating at 145.7 nm has a spectral width of 0.8 nm (FWHM). Efficient spectral narrowing down to 0.1 nm has been achieved with a 32/sup 0/ appex angle MgF/sub 2/ prism inserted in themore » cavity giving 3.5 MW peak power at 15 atm of Kr gas pressure. Wavelength conversion by stimulated Raman scattering in high-pressure H/sub 2/ gas has been demonstrated for efficient extension of the laser wavelength.« less
  • In several low-field Nuclear Magnetic Resonance (LF-NMR) and surface nuclear magnetic resonance applications, i.e., in the frequency range of kHz, high sensitivity magnetic field detectors are needed. Usually, low-T{sub c} superconducting quantum interference devices (SQUIDs) with a high field sensitivity of about 1 fT/Hz{sup 1/2} are employed as detectors. Considering the flux trapping and operational difficulties associated with low-T{sub c} SQUIDs, we designed and fabricated liquid-nitrogen-cooled Cu coils for NMR detection in the kHz range. A cooled coil system consisting of a 9-cm diameter Cu coil and a low noise preamplifier was systematically investigated and reached a sensitivity of 2more » fT/Hz{sup 1/2} at 77 K, which is 3 times better compared to the sensitivity at 300 K. A Q-switch circuit as an essential element for damping the ringing effects of the pickup coil was developed to acquire free induction decay signals of a water sample with minimum loss of signal. Our studies demonstrate that cooled Cu coils, if designed properly, can provide a comparable sensitivity to low-T{sub c} SQUIDs.« less
  • A new method for rapid approximation of electromagnetic (EM) fields for high-frequency sounding (HFS) over a layered earth is presented in this paper. The essence of this method uses a Q-factor correction for extending a closed-form, half-space analytic solution to a layered earth model. Use of the Q-factor in this context was first studied by Wait (1953, 1962). Kraichman (1976) also discusses the problem of when the Q-factor method can be used to provide a good approximation to an exact layered earth solution. According to Wait (1962) and Kraichman (1976), the Q-factor approach may be used if the dipole fieldsmore » can be approximated by a single, normally incident plane wave at the receiver in the top layer. Fortunately, for the high-frequency range of interest (300 kHz to 30 MHz) and with moderately conductive and dielectric earth models, the Q-factor method (also called the HFS Q-method) is usually a good approximation to the exact solution for a layered earth. Examples of computing layered-earth responses using the HFS Q-method, an image theory method, and an exact numerical integration method are given for several typical models encountered in shallow HFS studies. Because the Q-factor method does not require any numerical integrations, the layered-earth HFS Q-method algorithm is fast (even on PCs). In general, the computations require only elementally complex functions, and in one case, modified Bessel functions of a complex argument.« less
  • We have achieved single-mode operation in a pulsed hybrid optically pumped D{sub 2}O far-infrared laser. The active volume of the resonator was divided into two sections separated by a thin plastic foil. The larger section served as the main gain medium and the shorter section as the mode selective element. The vapor pressure in the smaller volume was either very low or alternatively about three times higher than the pressure in the main part. In both cases single-mode operation was achieved without any reduction of the total output energy.