Miniature Biplanar Coils for Alkali-Metal-Vapor Magnetometry

Free-induction-decay magnetic field imaging with a microfabricated Cs vapor cell

“…These devices are already commercially available and have been widely used in the development of magnetoencephalography (MEG) applications; however, they require extensive * d.hunter@strath.ac.uk magnetic shielding in order to function due to their limited dynamic range. Additionally, OPM array density is often constrained by crosstalk between neighbouring sensors, although recent advancements in compact bi-planar coil design and fabrication techniques can aid in alleviating these issues [18]. Therefore, most OPM-based MEG experiments provide centimeter-scale spatial resolution as each module is self-contained and requires field modulation to operate [19,20].…”

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

“…As a final remark, the square-wave NMR signal may in principle be recorded at any magnetic field, given a sufficiently sensitive detector. In this work, the nT bias field was chosen to use a zero-field OPM of sensitivity around 10 fT/√Hz, although the technical noise background (such as mains-hum noise) is much larger, on the order of 1 pT/√Hz. Miniaturized versions of zero-field OPMs are produced on a medium commercial scale , for research use in magnetoencephalography , and other biomagnetic imaging studies.…”

“…The shield presents no additional operating constraints; indeed, it allows the apparatus to be carried freely around the room and placed within a few meters of an MRI scanner in background fields of several tens of mT without any need to compensate for background drifts. For further technical details of the OPM we refer the reader to the Supporting Information, plus past work . The signal shown is processed minimally, where data points during each π-pulse and up to 5 ms afterward are excluded (where the magnetometer output saturates) and mains-hum noise is suppressed by applying a 45–55 Hz band-stop filter.…”

“…For further technical details of the OPM we refer the reader to the Supporting Information, plus past work. 31 The signal shown is processed minimally, where data points during each π-pulse and up to 5 ms afterward are excluded (where the magnetometer output saturates) and mains-hum noise is suppressed by applying a 45−55 Hz band-stop filter. The solid red curve, B z (t) = (190 pT) sgn(sin 20πt) exp(−t/T 1 ), fits to the remaining data The middle panel of Figure 2 shows the OPM signal when the starting magnetic field is much lower, 50 μT or around Earth's field, where there is no major alternation seen above the noise background.…”

Real-time polarimetry of hyperpolarized $^{13}$C nuclear spins using an atomic magnetometer

“…The magnetic shield provides a simple and convenient way to isolate the detector from unknown and/or time-dependent background magnetic fields. For further technical details of the OPM we refer the reader to the Supporting Information, plus past work 31 . The signal shown is processed minimally, where data points during each π pulse and up to 5 ms afterwards are excluded (where the magnetometer output saturates) and mains-hum noise is suppressed by applying a 45-to-55-Hz band-stop filter.…”