Miniature biplanar coils for alkali-metal-vapor magnetometry

Atomic spin sensors offer precision measurements using compact, microfabricated packages, placing them in a competitive position for both market and research applications. Performance of these sensors such as dynamic range may be enhanced through magnetic field control. In this work, we discuss the design of miniature coils for three-dimensional, localized field control by direct placement around the sensor, as a flexible and compact alternative to global approaches used previously. Coils are designed on biplanar surfaces using a stream-function approach and then fabricated using standard printed-circuit techniques. Application to a laboratory-scale optically pumped magnetometer of sensitivity $\sim$20 fT/Hz$^{1/2}$ is shown. We also demonstrate the performance of a coil set measuring $7 \times 17 \times 17$ mm$^3$ that is optimized specifically for magnetoencephalography, where multiple sensors are operated in proximity to one another. Characterization of the field profile using $^{87}$Rb free-induction spectroscopy and other techniques show $>$96% field homogeneity over the target volume of a MEMS vapor cell and a compact stray field contour of $\sim$1% at 20 mm from the center of the cell

Miniature biplanar coils for alkali-metal-vapor Magnetometry

Atomic spin sensors offer precision measurements using compact microfabricated packages, placing them in a competitive position for both market and research applications. The performance of these sensors, such as the dynamic range, may be enhanced through magnetic field control. In this work, we discuss the design of miniature coils for three-dimensional localized field control by direct placement around the sensor, as a flexible and compact alternative to global approaches used previously. Coils are designed on biplanar surfaces using a stream-function approach and then fabricated using standard printed-circuit techniques. Application to a laboratory-scale optically pumped magnetometer of sensitivity approximately 20fT/√Hz is shown. We also demonstrate the performance of a coil set measuring 7×17×17mm3 that is optimized specifically for magnetoencephalography, where multiple sensors are operated in close proximity to one another. Characterization of the field profile using 87Rb free-induction spectroscopy and other techniques show >96% field homogeneity over the target volume of a MEMS vapor cell and a compact stray-field contour of approximately 1% at 20 mm from the center of the cell

Miniature Biplanar Coils for Alkali-Metal-Vapor Magnetometry

| openaire: EC/H2020/820393/EU//macQsimal | openaire: EC/H2020/766402/EU//ZULF | openaire: EC/H2020/754510/EU//PROBIST Funding Information: The work was funded by: the European Union Horizon 2020 research and innovation programme under project macQsimal (Grant Agreement No. 820393); the Horizon H2020 Marie Skłodowska-Curie Actions projects ITN ZULF-NMR (Grant Agreement No. 766402) and PROBIST (Grant Agreement No. 754510); the Spanish MINECO project OCARINA (the PGC2018-097056-B-I00 project funded by MCIN/AEI/10.13039/501100011033/FEDER, “A way to make Europe”); the Severo Ochoa program (Grant No. SEV-2015-0522); the Generalitat de Catalunya through the CERCA program; the Agència de Gestió d’Ajuts Universitaris i de Recerca under Grant No. 2017-SGR-1354; the Secretaria d’Universitats i Recerca del Departament d’Empresa i Coneixement de la Generalitat de Catalunya, cofunded by the European Union Regional Development Fund within the ERDF Operational Program of Catalunya (project QuantumCat, ref. 001-P-001644); the Fundació Privada Cellex; and the Fundació Mir-Puig. M.C.D.T. acknowledges financial support through the Junior Leader Postdoctoral Fellowship Programme from the “La Caixa” Banking Foundation (project LCF/BQ/PI19/11690021). We also thank Jacques Haesler, Sylvain Karlen, and Thomas Overstolz of the Centre Suisse d’Electronique et de Microtechnique SA (CSEM) in Neuchâtel (Switzerland) for supplying the MEMS vapor cells. Publisher Copyright: © 2022 American Physical Society.Atomic spin sensors offer precision measurements using compact microfabricated packages, placing them in a competitive position for both market and research applications. The performance of these sensors, such as the dynamic range, may be enhanced through magnetic field control. In this work, we discuss the design of miniature coils for three-dimensional localized field control by direct placement around the sensor, as a flexible and compact alternative to global approaches used previously. Coils are designed on biplanar surfaces using a stream-function approach and then fabricated using standard printed-circuit techniques. Application to a laboratory-scale optically pumped magnetometer of sensitivity approximately 20fT/Hz is shown. We also demonstrate the performance of a coil set measuring 7×17×17mm3 that is optimized specifically for magnetoencephalography, where multiple sensors are operated in close proximity to one another. Characterization of the field profile using 87Rb free-induction spectroscopy andother techniques show >96% field homogeneity over the target volume of a MEMS vapor cell and a compact stray-field contour of approximately 1% at 20 mm from the center of the cell.Peer reviewe

Real-Time Polarimetry of Hyperpolarized ¹³C Nuclear Spins Using an Atomic Magnetometer

We introduce a method for nondestructive quantification of nuclear spin polarization, of relevance to hyperpolarized spin tracers widely used in magnetic resonance from spectroscopy to in vivo imaging. In a bias field of around 30 nT we use a high-sensitivity miniaturized 87Rb-vapor magnetometer to measure the field generated by the sample, as it is driven by a windowed dynamical decoupling pulse sequence that both maximizes the nuclear spin lifetime and modulates the polarization for easy detection. We demonstrate the procedure applied to a 0.08 M hyperpolarized [1–13C]-pyruvate solution produced by dissolution dynamic nuclear polarization, measuring polarization repeatedly during natural decay at Earth’s field. Application to real-time and continuous quality monitoring of hyperpolarized substances is discussed