G01R33/26

MAGNETIC FIELD MEASUREMENT APPARATUS AND MAGNETIC FIELD MEASUREMENT METHOD

A magnetic resonance member 1 includes a crystal structure and is capable of electron spin quantum operations with microwaves of different frequencies corresponding to arrangement orientations of a vacancy and an impurity in a crystal lattice. A magnetic field transmission unit 4 senses a measurement target magnetic field at plural measurement positions different from each other, and applies application magnetic fields corresponding to the measurement target magnetic field sensed at the plural measurement positions to the magnetic resonance member 1 along respective different directions corresponding to the aforementioned arrangement orientations. A measurement control unit 21 controls a high frequency power supply 12, and determines detection values detected by a detecting device (an irradiating device 5 and a light receiving device 6) of the physical phenomena corresponding to the plural measurement positions. A calculation unit 22 calculates the measurement target magnetic field at the plural measurement positions on the basis of the detection values.

ARRAY OF MAGNETOMETERS OPERATING IN ZERO FIELD AND ASSOCIATED METHOD FOR CALIBRATING INTER-MAGNETOMETER COUPLINGS

The invention relates to a method for determining a coupling between magnetometers of an array of N magnetometers, for example with optical pumping, where each magnetometer comprises a field cancellation system capable of being activated to operate the magnetometer in zero field. This method comprises a first phase (P1) during which the N magnetometers are separated into N−1 magnetometers whose field cancellation system is deactivated and a measuring magnetometer whose field cancellation system is activated. This first phase comprises: the generation (GENj), by the magnetometers, of a plurality of reference magnetic fields of known amplitudes and distinct directions, the measurement (MESi), by the measuring magnetometer, of the ambient magnetic field on a plurality of measurement axes determination (CALCij) of coupling coefficients between the measuring magnetometer and each of the N magnetometers from said measurement and said known amplitudes.

Elliptical polarisation magnetometer with two radiofrequency field components for parametric resonance detection in absorption

A parametric resonance magnetometer is provided comprising a cell filled with an atomic gas; an optical pumping source arranged to emit a light beam in a direction of the cell; a polarization device configured so that by the effect of the light beam, the atomic gas simultaneously acquires a state aligned according to an alignment direction and a state oriented according to an orientation direction; a parametric resonance excitation source configured to generate a radiofrequency magnetic field in the cell; and a device to detect parametric resonances and to measure an absorption of the light beam by the atomic gas. The parametric resonance excitation source is configured so that the radiofrequency magnetic field consists of two components orthogonal to one another, each oscillating at its natural oscillation frequency. The two components include a component longitudinal to the orientation direction and a component longitudinal to the alignment direction.

Elliptical polarisation magnetometer with two radiofrequency field components for parametric resonance detection in absorption

A parametric resonance magnetometer is provided comprising a cell filled with an atomic gas; an optical pumping source arranged to emit a light beam in a direction of the cell; a polarization device configured so that by the effect of the light beam, the atomic gas simultaneously acquires a state aligned according to an alignment direction and a state oriented according to an orientation direction; a parametric resonance excitation source configured to generate a radiofrequency magnetic field in the cell; and a device to detect parametric resonances and to measure an absorption of the light beam by the atomic gas. The parametric resonance excitation source is configured so that the radiofrequency magnetic field consists of two components orthogonal to one another, each oscillating at its natural oscillation frequency. The two components include a component longitudinal to the orientation direction and a component longitudinal to the alignment direction.

MULTI-FREQUENCY EXCITATION SCHEMES FOR HIGH SENSITIVITY MAGNETOMETRY MEASUREMENT WITH DRIFT ERROR COMPENSATION

A system for magnetic detection includes a nitrogen vacancy (NV) diamond material, a radio frequency (RF) excitation source that provides RF excitation to the NV diamond material, an optical excitation source that provides optical excitation to the NV diamond material, an optical detector that receives an optical signal emitted by the NV diamond material, a magnetic field generator that generates a magnetic field applied to the NV diamond material, and a controller. The controller controls the RF excitation source to apply a first RF excitation having a first frequency and a second RF excitation having a second frequency. The first frequency is associated with a first slope point of a fluorescence intensity response of an NV center orientation of a first spin state, and the second frequency is associated with a second slope point of the fluorescence intensity response of the NV center orientation of the first spin state.

MULTI-FREQUENCY EXCITATION SCHEMES FOR HIGH SENSITIVITY MAGNETOMETRY MEASUREMENT WITH DRIFT ERROR COMPENSATION

A system for magnetic detection includes a nitrogen vacancy (NV) diamond material, a radio frequency (RF) excitation source that provides RF excitation to the NV diamond material, an optical excitation source that provides optical excitation to the NV diamond material, an optical detector that receives an optical signal emitted by the NV diamond material, a magnetic field generator that generates a magnetic field applied to the NV diamond material, and a controller. The controller controls the RF excitation source to apply a first RF excitation having a first frequency and a second RF excitation having a second frequency. The first frequency is associated with a first slope point of a fluorescence intensity response of an NV center orientation of a first spin state, and the second frequency is associated with a second slope point of the fluorescence intensity response of the NV center orientation of the first spin state.

Geolocation of Magnetic Sources Using Vector Magnetometer Sensors

System and methods for determining an angle and/or geolocation of a dipole magnetic source relative to one or more DNV sensors. The system may include one or more DNV sensors, and a controller. The controller is configured to activate the DNV sensors, receive a set of vector measurements from the DNV sensors, and determine an angle of a magnetic source relative to the one or more DNV sensors based on the received set of vector measurements from the DNV sensors.

Geolocation of Magnetic Sources Using Vector Magnetometer Sensors

System and methods for determining an angle and/or geolocation of a dipole magnetic source relative to one or more DNV sensors. The system may include one or more DNV sensors, and a controller. The controller is configured to activate the DNV sensors, receive a set of vector measurements from the DNV sensors, and determine an angle of a magnetic source relative to the one or more DNV sensors based on the received set of vector measurements from the DNV sensors.

TIME-MULTIPLEXED DUAL ATOMIC MAGNETOMETRY
20230236270 · 2023-07-27 ·

Time-multiplexed atomic magnetometry uses first and second atomic vapor cells to measure an external magnetic field. Each vapor cell operates according to a sequence of alternating pumping and probing stages. However, the sequences are temporally offset from each other such that the second vapor cell is pumped while the first vapor cell is probed, and the first vapor cell is pumped while the second vapor cell is probed. With this time-multiplexed operation, the external magnetic field can be measured without any time gaps. The Hilbert transform of the signals may be taken to obtain their instantaneous phases, which may then be interleaved to form a single gapless time sequence that represents the external magnetic field over a time window that lasts for several continuous pumping/probing stages.

TIME-MULTIPLEXED DUAL ATOMIC MAGNETOMETRY
20230236270 · 2023-07-27 ·

Time-multiplexed atomic magnetometry uses first and second atomic vapor cells to measure an external magnetic field. Each vapor cell operates according to a sequence of alternating pumping and probing stages. However, the sequences are temporally offset from each other such that the second vapor cell is pumped while the first vapor cell is probed, and the first vapor cell is pumped while the second vapor cell is probed. With this time-multiplexed operation, the external magnetic field can be measured without any time gaps. The Hilbert transform of the signals may be taken to obtain their instantaneous phases, which may then be interleaved to form a single gapless time sequence that represents the external magnetic field over a time window that lasts for several continuous pumping/probing stages.