Abstract: Certain aspects of the present disclosure provide methods and apparatus for closed-loop control of a system using one or more electron paramagnetic resonance (EPR) sensors located on-site. With such EPR sensors, a change can be applied to the system, the EPR sensors can measure the effect(s) of the change, and then adjustments can be made in real-time. This feedback process may be repeated continuously to control the system.

Abstract: The magnetic field detector includes an x-axis magnetic sensor, a y-axis magnetic sensor, and a z-axis magnetic sensor for detecting magnetic field components in three orthogonal axis directions. Each of the magnetic sensors includes a magnetic impedance element having an impedance that varies in accordance with an ambient magnetic field and an output circuit configured to output a magnetic field detection value that varies in accordance with the impedance of the magnetic impedance element. The magnetic field detector includes an oscillator configured to supply a common drive signal to the magnetic impedance element of each of the magnetic sensors, wherein each of the magnetic sensors outputs, in response to the drive signal, the magnetic field detection value from the output circuit.

Abstract: Devices for determining a state of a magnetic field-generating article are provided. In various embodiments, a device comprises: a single crystal diamond having a plurality of NV centers, the single crystal diamond configured to be disposed adjacent to a magnetic field-generating article, and configured to generate a fluorescent signal in response to being illuminated by a light source; a coherent light source configured to generate a light beam directed at the single crystal diamond; a microwave (MW) radiation source configured to irradiate the single crystal diamond with a MW signal; a magnetic field source configured to apply a bias magnetic field to the single crystal diamond; a photosensor configured to collect the fluorescent signal generated by the single crystal diamond; and a computing node operatively coupled to each of the coherent light source, the MW radiation source, the magnetic field source, and the photosensor.

Abstract: Systems and methods for determining orientations measurements are provided. In one aspect, the method includes receiving a magnetic field state of an object, receiving a magnetic field measurement associated with the object, receiving an inertial measurement unit (IMU) measurement associated with the object, receiving a previous gravitational state term associated with the object, determining a gravitational acceleration state term based on the IMU measurement and the previous gravitational state term, determining a magnetic field state term based on the IMU measurement, the magnetic field measurement, and the gravitational acceleration term, and determining an orientation of the object using the gravitational acceleration state term and the magnetic field state term. The magnetic field measurement may be received from a magnetometer, and the IMU measurement may be received from a gyroscope and an accelerometer.

Abstract: An embodiment of the present utility model relates to a balun assembly, including: an outer conductive tube body disposed around an electrical cable, the outer conductive tube body including a first portion and a second portion detachably connected to each other; a conductive connection member electrically connecting the outer conductive tube body to the electrical cable; and an insulative material disposed between the outer conductive tube body and the electrical cable. An embodiment of the present utility model further relates to a magnetic resonance device including the balun assembly.

Abstract: A sulfurization detection resistor includes: a rectangle-shaped insulating substrate; pair of front electrodes formed at both ends facing each other on a surface of the insulating substrate; plurality of sulfurization detection conductors arranged in parallel between the paired front electrodes; plurality of resistors connected between the ends of each of the sulfurization detection conductors and the paired front electrodes; and sulfide gas impermeable protective film that covers all of the resistors and some of the sulfurization detection conductors, wherein each of the sulfurization detection conductors has a sulfurization detection unit exposed from a window hole in the protective film; and by covering the sulfurization detection units with different types of sulfurization rate adjustment layers formed of an acrylic resin, a silicon resin, and the like, timing of disconnection is set so as to vary in response to a cumulative amount of sulfurization in each of the sulfurization detection units.

Abstract: Methods and systems are provided for clay detection, clay typing, and clay volume quantification using electromagnetic measurements on a porous media sample at a low frequency less than 5000 Hz. The electromagnetic measurements are used to determine and store permittivity data that characterizes permittivity of the porous media sample at the low frequency less than 5000 Hz. The low frequency electromagnetic measurements can be performed in a laboratory, at a wellsite or other surface location. The low frequency electromagnetic measurements are nondestructive, and the results indicate that the methods and systems are highly sensitive to the existence of clays.

Abstract: A method of enhancing the nuclear spin polarization of target molecules (10) uses a hyperpolarized source material (12) that is co-confined with the target molecules (10) in a porous molecular matrix (20). The matrix (20) may be a D4R-polysiloxane copolymer such as polyoligosiloxysilicone number two (PSS-2) that has recesses of an appropriate diameter. A source material (12), such as parahydrogen, is transferred to the matrix (20) together with the target molecules (10), and an external pressure is applied to force them into the recesses of the matrix (20). The nano-confinement of the source material (12) and target molecules (10) together enables or enhances a transfer of spin polarization from the source material (12) to the target molecules (10). When the target molecules (10) are removed from the matrix (20), the enhanced spin polarization greatly enhances the signal strength of the target molecules (10) in any subsequent magnetic resonance measurement.

Abstract: A magnetic resonance imaging apparatus includes a T/R switch. The T/R switch includes a double sided microstripline based hybrid couplers with a top side and a bottom side each including two concentric microstripline based hybrid couplers. Each of the two concentric microstripline based hybrid couplers includes an inner microstripline based hybrid coupler and an outer microstripline based hybrid coupler. The inner microstripline based hybrid coupler forms an inner loop of the two concentric microstripline based hybrid couplers and the outer microstripline based hybrid coupler forms an outer loop. In a transmission mode, the inner microstripline based hybrid coupler and the outer microstripline based hybrid coupler at the top side of the dual-tuned T/R switch are activated. In a receiving mode the inner microstripline based hybrid coupler and the outer microstripline based hybrid coupler at the top side and at the bottom side of the dual-tuned T/R switch are activated.

Abstract: A calibration device comprising: a plurality of magnetic sensors positioned at the calibration device, the plurality of magnetic sensors defining a space; a controller configured to be positioned in the space defined by the plurality of magnetic sensors, wherein the controller includes a magnetic transmitter; and one or more processors configured to: cause the magnetic transmitter to generate magnetic fields; receive signals from the plurality of magnetic sensors that are based on characteristics of the magnetic fields received at the plurality of magnetic sensors; calculate, based on the signals received from the plurality of magnetic sensors, positions and orientations of the plurality of magnetic sensors relative to a position and orientation of the magnetic transmitter; and determine whether the calculated positions and orientations of the plurality of magnetic sensors are within one or more threshold limits of known positions and orientations of the plurality of magnetic sensors.

Abstract: A magnetic sensor device includes a first chip including a first magnetic sensor, a second chip including a second magnetic sensor and a third magnetic sensor, and a support having a reference plane. The first magnetic sensor includes at least one first magnetic detection element, and detects a first component of an external magnetic field. The second magnetic sensor includes at least one second magnetic detection element, and detects a second component of the external magnetic field. The third magnetic sensor includes at least one third magnetic detection element, and detects a third component of the external magnetic field. The first chip and the second chip are mounted on the reference plane.

Abstract: Systems and methods for monitoring a filter in, for example, an immersion cooled system are described. In one embodiment the application pertains to a process comprising employing a filter media to filter fluid wherein one or more electrical properties change depending upon pH of the filter fluid. The one or more electrical properties may be measured to monitor the filter. If desired, the filter media's electrical properties may be modified based on the configuration of the filter to facilitate the measurements.

Abstract: A system for tracking a below-ground transmitter from an aerial receiver. The receiver has an antenna assembly, a processor, and a propulsion system. The antenna assembly detects the magnetic field from an underground transmitter and generates an antenna signal. The processor is programmed to receive the antenna signal and generate a command signal, which moves the receiver to a position above the transmitter. Once in the desired position, which may be a reference plane at a fixed elevation, the antenna assembly measures the magnetic field to determine the location of the drill bit along borepath.

Abstract: A tension measuring method installs a reel having a cylindrical coil forming part on a cable to be measured, forms a coil by winding a conductor around the coil forming part, measures a magnetic hysteresis loop of the cable by supplying a current to the coil to generate a magnetic field, and computes a tension of the cable using a parameter determined from the hysteresis loop. A magnetic field sensor and a magnetic flux sensor are provided inside a through hole in the coil forming part, and the cable is positioned inside the through hole. The magnetic field is varied so that the hysteresis loop includes a near-saturation magnetization region, to measure the hysteresis loop using the sensors. The parameter is selected from a magnetic flux or a magnetic flux density, a remanent magnetization, a coercivity, a magnetic permeability, and a hysteresis loss in the near-saturation magnetization region.

Abstract: An apparatus for producing magnetic field gradients includes (a) a first planar electromagnet coil set configured to produce a first magnetic field gradient with respect to a first axis, (b) a second planar electromagnet coil set configured to produce a second magnetic field gradient with respect to a second axis that is orthogonal to the first axis, (c) a third planar electromagnet coil set configured to produce a third magnetic field gradient with respect to a third axis that is orthogonal to the first and second axes, and (d) a controller configured to selectively provide power to the first, second, and/or third electromagnet coil sets to sequentially produce a localization magnetic field gradient with respect to each of the first, second, and third axes, at least a portion of each localization magnetic field gradient having a monotonically-varying magnetic field magnitude along a respective axis.

Abstract: Disclosed is a multi-channel atomic magnetic detector (100), including at least one detection assembly, with each detection assembly including a plurality of detection air chambers (130) in the same plane and a light-splitting member (110) for allocating polarized beams from a light source (180) to each detection air chamber (130) in the detection assembly, wherein the plurality of detection air chambers (130) of each detection assembly are arranged in a centrally symmetric manner or an axially symmetric manner relative to the light-splitting member (110). The multi-channel atomic magnetic detector (100) has a high detection density and is beneficial for noise reduction.

Abstract: A magnetic field measuring apparatus includes a digital FLL circuit. The digital FLL circuit includes a first amplifier configured to amplify voltage output by a superconducting quantum interference device in accordance with strength of a magnetic field strength, an AD converter configured to, convert analog signals to first digital values, an integrator configured to integrate the first digital values output by the AD converter, a DA converter configured to receive an integral value output by the integrator as a second digital value, convert the second digital value to voltage, and output the converted voltage, a signal switcher configured to connect an output of the first amplifier or an output of the DA converter to an input of the AD converter, and a storage unit configured to store a correction value that corrects the integral value received by the DA converter.

Abstract: A speed detection device includes a comparator module, a sensor lead with a node connected to the comparator module, and a limit set module. The limit set module is connected to the sensor lead node and to the comparator by an upper limit lead and a lower limit lead to provide upper and lower limits to the comparator that vary according to amplitude variation in voltage applied to the sensor lead.

Abstract: A sensor integrated circuit including a regulator for generating a regulated voltage includes a digital load configured to draw a load current from the regulator in response to a clock signal during in situ operation and a comparator configured to determine the absence or presence of a fault during in situ operation. The load current is less than or equal to a predetermined level in the absence of a fault and is greater than the predetermined level in the presence of a fault. The comparator is responsive to the load current and to a threshold level and is configured to generate a comparator output signal having a level indicative of whether the load current is less than or greater than the threshold level in order to thereby determine the absence or presence of a fault during in situ operation, respectively.

Abstract: Systems and methods for providing a visualization capability to map magnetic fields. The system utilizes a high-sensitivity magnetic field sensor (e.g., a magnetometer inside a tube made of magnetic shielding material) disposed on one side of a magnetic field modulation screen to acquire measurement data representing an image of a magnetic field. The magnetic field modulation screen includes a multiplicity of magnetic field-generating pixel elements (e.g., current-carrying loops made of electrically conductive material). Optionally, the system also uses compressive sensing techniques to reduce the amount of measurement data required to reconstruct an image of the original magnetic field. Compressive sensing is enabled by not supplying current to a different selected individual magnetic field-generating pixel element of the magnetic field modulation screen at successive sampling times.