Abstract: In order to measure the temperature parameters of magnetic materials, in a process and an apparatus for measuring the characteristics of variation of magnetic induction of magnetic material with respect to temperature, a probe is provided at any one point A within the effective imaging range of an MR apparatus, the magnetic material to be tested also being provided at point A. The material is contacted directly with a heating unit, and a temperature sensor is attached to said magnetic material to be tested. The temperature control unit adjusts and controls the heating unit to heat the magnetic material to be tested based on the information collected by the temperature sensor. A processing unit of the MR system controls the probe at A in real-time and receiving the MR signals for feeding into the processing unit of the MR system, and the magnetic induction at A being obtained after the analysis of the system.

Abstract: The present invention relates generally to nuclear magnetic resonance (NMR) techniques for both spectroscopy and imaging. More particularly, the present invention relates to methods in which hyperpolarized noble gases (e.g., Xe and He) are used to enhance and improve NMR and MRI. Additionally, the hyperpolarized gas solutions of the invention are useful both in vitro and in vivo to study the dynamics or structure of a system. When used with biological systems, either in vivo or in vitro, it is within the scope of the invention to target the hyperpolarized gas and deliver it to specific regions within the system.

Abstract: A ferromagnetic detection pillar having one or more applied magnetic field sources and one or more magnetic field sensors, with the magnets and sensors arranged and adapted to detect a ferromagnetic threat object on one side of the pillar. A detection device, such as a motion detector or infrared detector, is also provided, to detect the presence of an object on a selected side of the pillar. A single free-standing pillar can be used, or two or more free-standing pillars can be arranged to constitute a variable aperture detection portal. Single sensors or multiple-sensor configurations can be used.

Abstract: The reversible transverse susceptibility of magnetic nanoparticles is used to achieve magnetic flux amplification in magnetic resonance settings. Nanoparticles having substantially uniaxial or unidirectional magnetic anisotropy and a reversible transverse susceptibility in the presence of the high DC magnetic field provide either or both of an amplification of the generated signal of an inductive coil or the detected signal of an inductive coil.

Abstract: An apparatus for generating a stabilized frequency signal is disclosed. The apparatus includes a quantum absorber having first, second, and third energy states. The quantum absorber is irradiated by a first radiation source that generates electromagnetic radiation having a frequency, ?L, that induces transitions between the first and third energy states. The quantum absorber is also irradiated by a second radiation source that generates electromagnetic radiation having a frequency, ?M, that induces transitions between the first and second energy states. A detector that generates a detector signal indicative of the level of radiation leaving the quantum absorber in a frequency range including ?L is used by a number of servo loops. One of the servo loops determines the value of ?L that minimizes or maximizes the detector signal and a second servo loop determines an offset signal that reduces the dependence of ?M on the intensity of the first radiation source.

Abstract: Embodiments of the invention relate to a system and method for non-destructively inspecting a component that is at least partially made of a composite material. In one embodiment, the composite component can be a ceramic matrix composite vane or a liner for a turbine engine. Aspects of the invention involve imaging the component using a magnetic resonance imaging (MRI) apparatus. To enhance the image, the component can be infiltrated with at least one contrast media, which can be in liquid or gas form. By imaging the component using the MRI apparatus, internal and/or external defects of the component can be revealed. In addition, internal and/or external features of interest can examined for dimensional accuracy, among other things.

Abstract: The present invention provides a high sensitivity atomic magnetometer and methods of measuring low intensity magnetic fields that relate to the use of an alkali metal vapor and a buffer gas; increasing the magnetic polarization of the alkali metal vapor thereby increasing the sensitivity of the alkali metal vapor to a low intensity magnetic field; probing the magnetic polarization of the alkali metal vapor, the probing means providing an output from the alkali metal vapor, the output including characteristics related to the low intensity magnetic field; and measuring means that receives the output, determines the characteristics of the low intensity magnetic field, and provides a representation of the low intensity magnetic field. In addition, the invention relates to a magnetometer and methods that provide a representation of a first magnetic field originating within a sample volume. The sample volume may be part or all of a subject, such as a human subject.

Abstract: A technique for eliminating edge artifacts in magnetic microscopy includes the steps of scanning a SQUID over an object under study to acquire values of magnetic fields produced by currents running in the object to create a first data set having N data points. At the end of the first data set, N zero data points are added to create a second data set having 2N data points. Fast Fourier Transform (FFT) is further applied to the 2N data set to obtain k-space having b(k) values. The b(k) values of the k-space are averaged, and the averaged b(k) values corresponding to k exceeding a predetermined k value are filtered off. A set of current density representations i(k) in the k-space are obtained to which inverse FFT is applied to obtain a map of current densities I(x,y) of the object. A system for performing the method of the present invention includes a software designed to suppress (or eliminate) edge artifacts present in the obtained images.

Abstract: The subject invention pertains to a method and apparatus for enhanced multiple coil imaging. The subject invention is advantageous for use in imaging devices, such as MRIs where multiple images can be combined to form a single composite image. In one specific embodiment, the subject method and apparatus utilize a novel process of converting from the original signal vector in the time domain to allow the subject invention to be installed in-line with current MRI devices.

Abstract: The present invention provides a high sensitivity atomic magnetometer and methods of measuring low intensity magnetic fields that relate to the use of an alkali metal vapor and a buffer gas; increasing the magnetic polarization of the alkali metal vapor thereby increasing the sensitivity of the alkali metal vapor to a low intensity magnetic field; probing the magnetic polarization of the alkali metal vapor, the probing means providing an output from the alkali metal vapor, the output including characteristics related to the low intensity magnetic field; and measuring means that receives the output, determines the characteristics of the low intensity magnetic field, and provides a representation of the low intensity magnetic field. In addition, the invention relates to a magnetometer and methods that provide a representation of a first magnetic field originating within a sample volume. The sample volume may be part or all of a subject, such as a human subject.

Abstract: A method for improving the magnetic resonance imaging contrast of a selected portion of a sample. A selected ferrimagnetic constituent is associated with the sample portion, by molecular or biological attachment or by some other means, so that the sample portion is distinguished from other adjacent portions of the sample that do not have the selected ferrimagnetic constituent associated therewith. Alternatively, the sample portion is suspected, but not yet confirmed, to have the selected ferrimagnetic constituent associated with it. Ferromagnetic resonance imaging is performed on the sample portion, and at least one resonance frequency ?0 of the sample portion is provided. At least one material parameter of the sample portion is measured at or near the frequency ?0, with enhanced imaging contrast relative to adjacent portions of the sample that do not have the selected ferrimagnetic constituent in association.

Abstract: The present invention provides a method and system to simultaneously use the microwave and Zeeman end resonances associated with the same sublevel of maximum (or minimum) azimuthal quantum number m to lock both the atomic clock frequency and the magnetic field to definite values. This eliminates the concern about the field dependence of the end-resonance frequency. In an embodiment of the system of the present invention, alkali metal vapor is pumped with circularly-polarized D1 laser light that is intensity-modulated at appropriate resonance frequencies, thereby providing coherent population trapping (CPT) resonances. In another embodiment, pumping with constant-intensity circularly-polarized D1 laser light enhances magnetic resonances that are excited by alternating magnetic fields oscillating at appropriate resonance frequencies.

Abstract: The present invention provides a high sensitivity atomic magnetometer and methods of measuring low intensity magnetic fields that relate to the use of an alkali metal vapor and a buffer gas; increasing the magnetic polarization of the alkali metal vapor thereby increasing the sensitivity of the alkali metal vapor to a low intensity magnetic field; probing the magnetic polarization of the alkali metal vapor, the probing means providing an output from the alkali metal vapor, the output including characteristics related to the low intensity magnetic field; and measuring means that receives the output, determines the characteristics of the low intensity magnetic field, and provides a representation of the low intensity magnetic field. In addition, the invention relates to a magnetometer and methods that provide a representation of a first magnetic field originating within a sample volume. The sample volume may be part or all of a subject, such as a human subject.

Abstract: A detector to detect metal fragments (especially in pre MRI scanning) comprising: a first loop of conducting material, means to feed an rf signal to the first loop, a second loop of conducting material, and means to detect an induced rf signal consequent to said rf signal in said first loop, said second loop being geometrically symmetrically arranged with said first loop such that the rf signal, induced is therein is substantially zero when there are no metal fragments in the close proximity of the sensor. Preferably the second loop comprises two halves arranged in anti-phase, such in the form of a figure of eight. The loops are arranged to be substantially co-planar, such as on a PCB.

Abstract: A method and facility for handling data regarding web activity of a population of users includes recording a selected web activity by a user and determining a cookie associated with the web activity. A plurality of different storage devices are provided. Each storage device is assigned a unique range of cookie values. A data set associated with the selected web activity is stored in the storage device that has an assigned range into which the cookie falls. The data sets are indexed by cookie for retrieval.

Abstract: Microcoils can be used in medical devices to enhance RF response signals and to create fields to enhance imaging capability in MRI imaging systems. An improved microcoil design includes a device to be inserted into a patient comprising a solid body having at least one pair of radially opposed microcoils physically associated with the solid body, each microcoil having an outside microcoil diameter of 6 mm or less, individual windings of each microcoil together defining a geometric plane for each microcoil, and the plane of each microcoil being parallel to the plane of another microcoil in the pair of radially opposed microcoils.

Abstract: A system for and method of determining and compensating for the effect of a field influencing object on a field sensor, preferably a coil, that is within a navigational domain. The navigational domain contains navigational magnetic energy and disturbing magnetic energy, and the field influencing object produces the disturbing magnetic energy in response to the navigational magnetic energy. The correction system includes a first transmitter for projecting into the navigational domain field energy in a first waveform sufficient to induce a first signal value in the sensing coil. The system also includes a second transmitter for projecting into the navigational domain field energy in a second waveform sufficient to induce a second signal value in the sensing coil. The system further includes a signal processor for receiving the first signal value and for receiving the second signal value to determine the effect of the electrically conductive object on the field sensor.

Abstract: A method of, an and apparatus for, creating an image of currents flowing through current paths in a microelectronic circuit such that the image of the currents has improved spatial resolution using filters. The filters increase the spatial resolution and eliminate noise and edge artifacts in magnetic field and electric field images of electronic circuits. In accordance with the method, a magnetic field image is created with a scanning SQUID microscope. A magnetic inversion technique is then used to convert the magnetic field image into a current density image. The current density image is filtered based upon known restrictions on the wiring geometry of the microelectronic circuit being imaged. The technique can also be applied to convert electric fields of a circuit from a scanning single electron transistor microscope into images of the voltage levels on the wires in the circuit.

Abstract: Microcoil designs are provided that enable unique RF response Field profiles that are particularly useful in MRI imaging procedures, particularly where fields of view outside of the medical device are desirable. These devices are particulatly for use within an organism, the device comprising an element having at least one RF receiver, the coils of said microcoils defining a cross-section that lies in a plane oriented at 0 to 90 (or 0 to 80) degrees to the longest axis of the device. Another way of describing the device is as a device for use in an organism, the device comprising an element having at least one wound microcoil with at least three windings on the microcoil. Each winding has an aspect ratio of greater than one. The aspect ratio of each winding is measured as the ratio of longest to shortest dimension in a cross section situated approximately transverse to the winding axis of the coil windings, the winding axis also being transverse to the longest axis of said device.

Abstract: The systems and methods of the present invention provide for MRI probes adapted for insertion into a plurality of body orifices, in order to evaluate the anatomy of proximate anatomic structures, to diagnose abnormalities thereof and to treat the diagnosed abnormalities. MRI probes are described that are suitable for use in the mediastinum, in the pancreaticohepaticobiliary system, in the tracheobronchopulmonary system, in the head and neck, in the genitourinary system, the gastrointestinal system, the vascular system, and in the evaluation, diagnosis and treatment of internal fluid collections.

Abstract: Method of detecting cracks in an object of an electrically conducting material that is covered by a non-conductive layer using a probe comprising a transmitter coil for inducing eddy currents in the object and a receiver coil comprising selecting a set of points of the object which are to be inspected; and which method further comprises for each point positioning the probe at the point, activating the transmitter coil to induce eddy currents in the object; creating a record of the signal provided by the receiver coil over a period of time; and examining the record and comparing it to reference records, wherein the presence or absence of a crack can be inferred from the comparison.

Abstract: A magnetometer for, among other things, measuring a magnetic field, associated with nuclear magnetic spins or electron spins received a specimen of a material that exhibits nuclear magnetic resonance or electron spin resonance at a resonant frequency &ggr;·Bm that is dependent on a magnetic flux density Bm of the magnetic field to be measured. The magnetometer has a transmission device for emitting a transmission signal into the specimen at at least one prescribable transmission frequency &ohgr;1 that has a frequency spacing from the resonant frequency &ggr;·Bm, and a reception device for receiving a mixed signal with mixed frequencies containing the resonant frequency &ggr;·Bm and the transmission frequency &ohgr;1 and for filtering out the resonant frequency &ggr;·Bm from at least one of the mixed frequencies as an indicator for the magnetic flux density Bm.

Abstract: A system for and method of determining and compensating for the effect of a field influencing object on a field sensor, preferably a coil, that is within a navigational domain. The navigational domain contains navigational magnetic energy and disturbing magnetic energy, and the field influencing object produces the disturbing magnetic energy in response to the navigational magnetic energy. The correction system includes a first transmitter for projecting into the navigational domain field energy in a first waveform sufficient to induce a first signal value in the sensing coil. The system also includes a second transmitter for projecting into the navigational domain field energy in a second waveform sufficient to induce a second signal value in the sensing coil. The system further includes a signal processor for receiving the first signal value and for receiving the second signal value to determine the effect of the electrically conductive object on the field senior.

Abstract: A diode laser-pumped magnetometer includes a diode laser that emits a polarized pumping laser beam with resonant optical radiation; and a K-cell through which a magnetic field is manifested from an independent source, the K-cell containing atoms with a dipole experiencing a torque due to the magnetic field. The atoms are excited by the resonant optical radiation of the pumping laser beam and periodically emitting a response radiation as they return to ground state such that the response radiation includes photons that indicate one unit of angular momentum indicative of the torque due to the magnetic field. Finally, a photodetector serves as a means for measuring the response radiation of the K-cell to indicate thereby a measure of the magnetic field in the K-cell from the independent magnetic source.

Abstract: A system and method are disclosed using continuous table motion while acquiring data to reconstruct MR images across a large FOV without significant slab-boundary artifacts that reduces acquisition time. At each table position, full z-encoding data are acquired for a subset of the transverse k-space data. The table is moved through a number of positions over the desired FOV and MR data are acquired over the plurality of table positions. Since full z-data are acquired for each slab, the data can be Fourier transformed in z, interpolated, sorted, and aligned to match anatomic z locations. The fully sampled and aligned data is then Fourier transformed in remaining dimension(s) to reconstruct the final image that is free of slab-boundary artifacts.

Abstract: A method of measuring a strength of a capillary-porous chemically active material while hardening, the capillary-porous chemically active material including therein a liquid which undergoes metamorphosis and which is present in the capillary-porous chemically active material in different stages during curing, the method is effected by performing a high frequency, spin-echo nuclear magnetic resonance measurement of each stage of the liquid; and correlating the high frequency, spin-echo nuclear magnetic resonance measurement with a predetermined relationship between the strength and the high frequency, spin-echo nuclear magnetic resonance measurement.

Abstract: A method for use during a procedure on a body. The method generates a display representing relative positions of two structure during the procedure.

Abstract: A method of performing synthetic aperture magnetometery on the signals from a target organ using an array of biomagnetic sensors positioned in a predetermined manner around the target organ, each sensor in the array having a position vector and an orientation vector relative to a common coordinate system encompassing the target organ.

Abstract: A magnetometer for, among other things, measuring a magnetic field, associated with nuclear magnetic spins or electron spins receives a specimen of a material that exhibits nuclear magnetic resonance or electron spin resonance at a resonant frequency &ggr;·Bm that is dependent on a magnetic flux density Bm of the magnetic field to be measured. The magnetometer has a transmission device for emitting a transmission signal into the specimen at at least one prescribable transmission frequency &ohgr;1 that has a frequency spacing from the resonant frequency &ggr;·Bm, and a reception device for receiving a mixed signal with mixed frequencies containing the resonant frequency &ggr;·Bm and the transmission frequency &ohgr;1 and for filtering out the resonant frequency &ggr;·Bm from at least one of the mixed frequencies as an indicator for the magnetic flux density Bm.

Abstract: A device for examining by nuclear magnetic resonance a volume having small depth, including means for creating a static homogeneous magnetic field B.sub.0 in which a volume to be examine is positioned, a system for creating magnetic field gradients in three directions of space, and a radio frequency transmission/reception system. The means for creating the static magnetic field B.sub.0, the field gradient system, and the radio frequency transmission/reception system are situated on a same side of an open surface, while the volume to be examined is situated on the other side of the surface. The device can be applied to magnetic resonance imaging.

Abstract: Magnetic resonance scanner has a radio-frequency system with transmission/reception antennas, and possibly a radio-frequency shield as well, and guides for a movable patient bed arranged in a basic field system and in a gradient system, with the electrical components of the radio-frequency system being embedded in a cylindrical, rigid carrier tube that penetrates the basic field system and the gradient system in the axial direction and which simultaneously serves as a carrier for the guides for the patient bed. The carrier tube is introducible as structural unit into the basic field and gradient system.

Abstract: This invention relates to a radical solution for nuclear magnetic resonance magnetometry, having resistance to magnetic field gradients over a wide temperature range. This solution consists of a nitroxide radical with the formula: ##STR1## in which R.sup.1, R.sup.2, R.sup.3 and R.sup.4, which may be identical or different, represent an alkyl group or an alkoxy group which may be deuterated, or in which the R.sup.1 -R.sup.2 and/or R.sup.3 -R.sup.4 couples together form a cycloalklyl or polycycloalkyl group which may be deuterated, and N represents .sup.14 N or .sup.15 N,dissolved in a solvent consisting of a dimethyl ether with the formula:CH.sub.3 O(CH.sub.2 CH.sub.2 O)n CH.sub.3 (II)in which n equals 3 or 4.

Abstract: A magnetic resonance imaging method comprises exciting spins in an investigation volume via a radio frequency pulse and the signal produced thereby is subsequently read-out after appropriate spatial encoding following a short echo time te. Repetition of the sequence required for spatial encoding occurs in a time interval tr under appropriate variation of the spatially encoding gradient. The radio frequency pulse utilized for excitation has a short time duration and therefore a large excitation band width so that a projection image through a thick projection slice is produced under application of no slice selection gradient or with only a weak slice selection gradient. The time interval tr is sufficiently minimized that the image recording time required for recording of an image lies in the range of one EKG cycle or below. This process of recording a projection image is continuously repeated and a contrast medium bolus administered during the course of this sequential recording.

Abstract: Apparatus for Nuclear Quadrupole Resonance testing a sample comprises: means for applying excitation to the sample to excite NQR resonance, the excitation comprising at least one excitation pulse, the or each pulse covering a selected excitation frequency range, for the or each pulse the phase of the excitation varying generally non-linearly with the excitation frequency over the selected range; and means for detecting the NQR response signal.

Abstract: The invention relates to a solution containing a nitroxide radical for magnetometry by nuclear magnetic resonance. This solution is constituted by a nitroxide radical of formula: ##STR1## in which R.sup.1, R.sup.2, R.sup.3 and R.sup.4, which can be the same or different, represent an alkyl group or an alkoxy group which may be deuterated, or in which the pairs R.sup.1 -R.sup.2 and/or R.sup.3 -R.sup.4 together form an optionally deuterated cycloalkyl or polycycloalkyl group, and N represent .sup.14 N or .sup.15 N, dissolved in a solvent having an oxidizing power and an appropriate viscosity.The solvent can be constituted by a mixture of water and two compounds respectively playing the part of the oxidizing agent and viscosity modifying agent, e.g. water, ethylene glycol and NalO.sub.4, or can be solely constituted by a mixture of water and an oxidizing agent able to modify the viscosity, such as acetic acid.

Abstract: A single-mode semiconductor laser for optical pumping in H.sup.e and .sup.4 He and high-sensitivity magnetometers based upon these systems. A distributed Bragg reflection (DBR) or distributed feedback (DFB) single mode, preferably InGaAs laser diode (1) which obviates the need for optomechanical arrangements and their inherent instabilities as required by the prior art laser pumped magnetometers. By constructing a DBR or DFB region (28) within the laser diode structure, the laser is forced to operate within a single-mode at a wavelength that is jointly determined by the gain of the laser medium and feedback from the Bragg grating. This wavelength is controllable in one of three ways: (1) temperature control (13) of the laser diode junction and grating, (2) injection current control (12) within the gain region, (3) current control (11) of the Bragg grating region or any combination of the three.

Abstract: In an apparatus having at least one detection coil (1) for the detection of nuclear magnetic resonance (NMR) from a sensitivity region of the detection coil (1) in the ground, whereby nuclear spins within the sensitivity region are excited by repeated coherent excitation, in each case, to precess in the earth's field and produce a small NMR induction voltage in the detection coil (1) which is introduced to a first amplifier (7), the detection coil (1) consists of at least two oppositely wound partial coils (2, 3) having parallel coil axes which are connected electrically in series and at least one compensation coil (8, 9, 10) is provided for additional compensation of spatially inhomogeneous interfering fields whose induction signal is introduced to a second amplifier (18, 19, 20) having adjustable amplification. In this fashion, in addition to the homogeneous portion, an inhomogeneous portion due to distant disturbances can be eliminated from the measured signal.

Abstract: A magnetic resonance monitor measures static and extremely low frequency magnetic fields in order to determine the degree of magnetic resonance with the magnetic moments of a biological substrate, more particularly resonance with the magnetic moments of a human body. A digital bandpass filter varies in response to the magnitude of the static magnetic field so that it selects frequencies of the oscillating magnetic field in accordance with the gyromagnetic equation. A spatial analyzer determines the three spatial components of the filtered signals representing the magnetic field oscillating parallel to the static magnetic field vector and the two circularly-polarized components rotating perpendicular to the static field with helicities opposite to each other. A resonance analyzer evaluates accurately the resonance yield which is the change in biochemical processes due to magnetic field exposures.

Abstract: A coupled radio frequency field and light polarization magnetometer. The polarization direction P and the direction of the radio frequency field B.sub.1 are kept parallel to one another and perpendicular to the field B.sub.0 which is to be measured. The polarizer is connected to the coil, which produces B.sub.1, and the assembly is rotated by a piezoelectric motor.

Abstract: A magnetometer is provided for detecting the intensity of a present magnetic field. The magnetometer includes a sample having a known resonance frequency response. A first source is provided for applying a first oscillating magnetic field having a first frequency to the sample. A second source is provided for applying a second oscillating magnetic field having a second frequency to the sample in a direction substantially transverse to the first oscillating magnetic field. A receiver is provided for detecting a frequency response output from the sample which is dependent upon the intensity of a present magnetic field so as to measure the intensity of the present magnetic field.

Abstract: A nuclear magnetic resonance probe is provided comprising a high frequency resonator (14, 16) having a resonant frequency, a first coaxial conductor (20) connected to the high frequency resonator, and a high frequency supply which supplies the first coaxial conductor (20) the resonant frequency of the high frequency resonator (14, 16). The high frequency supply includes a conductive sampling loop (40) at least partly placed in the high frequency resonator (14, 16) and a broad band, high frequency, amplifier (56) having an input (E) connected to the sampling loop (40) by a second coaxial conductor (50) and an output (S) connected to the first coaxial conductor (20). The assembly forming a high frequency loop oscillator locked to the resonant frequency of the high frequency resonator (14, 16).

Abstract: Resonance magnetometer with optical pumping using a monolithic laser. The laser (30) includes a single element (32) (crystal or fiber) whose length is modulated to provide both a wavelength and amplitude control.

Abstract: A differential resonance magnetometer, which includes a reference assembly and at least one measurement assembly. A polarization current is produced by the reference assembly is the same as a polarization current used in the measurement assembly. A feedback signal produced by the measurement assembly directly gives a difference between fields in the reference and measurement assemblies. Such a device may find particular application to magnetometry.

Abstract: A method for detecting the presence within a larger article of a specific substance containing quadrupolar atomic nuclei includes performing tests of parts of the article by placing the article adjacent to an array of coils (10), energizing with an rf source (20) the coils (10) in periods within a cyclic sequence to irradiate parts of the article with rf pulses of one or more frequencies at or close to a resonant frequency of quadrupolar atomic nuclei within the substance to be detected, connecting the coils (10) in other periods within the cyclic sequence to a phase-sensitive detecting and measuring circuit (15, 24-26) to measure response signals due to nuclear quadrupole resonances, and summing the response signals detected at corresponding instants over a number of cyclic sequences. Apparatus for detecting the presence of a specific substance analogous to the above method is also disclosed.

Abstract: The magnetometer according to the invention comprises a logic unit (50) receiving a resonance detection signal, a digital processor (60) supplying a number N, a digital-analog converter converting said number into current for establishing a feedback. The measurement of the field is directly digitally given by the processor.Use in magnetometry.

Abstract: Resonance magnetometer with optical pumping using a monolithic laser. The laser (30) includes a single element (32) (crystal or fiber) ensuring whose length is modulated to provide both a wavelength and amplitude control.

Abstract: A NMR magnetometer probe having a single resonator and a single radical solution. A single bottle contains the single radical solution. Further, a single resonator is tuned to one of the electric resonance frequencies of the solution. Such an NMR magnetometer probe may find particular application to the measurement of magnetic fields.

Abstract: Multiaxial resonance magnetometer. The magnetometer according to the invention incorporates means (40, 50, 60, Wx, Wy, Wz) for the sequential application of polarization fields having different directions. It then supplies (70) the components (Hmx, Hmy, Hmz) of the ambient field in accordance with these directions. Application in magnetometry.

Abstract: Slaved radio frequency field and light polarization magnetometer. The polarization direction (P) is slaved perpendicular to the field (Bo) to be measured, as well as the radio frequency field (Brf). Application to the measurement of weak magnetic fields such as the geomagnetic field.

Abstract: The invention relates to an organic material (5) usable in an electron paramagnetic resonance (EPR) magnetometer, as well as to a probe (3) using said material.The object of the invention is to provide a material simultaneously having a limited line width (EPR), good temperature characteristics and which does not react in the presence of water.This object is achieved with the aid of a radical cation salt of formula(Ar).sub.2..sup.+ X.sup.-in which Ar represents an aromatic hydrocarbon, which is either unsubstituted or substituted by at least one element chosen from within the group constituted by halogen atoms or alkyl and alkoxy radicals and X.sup.- is an anion chosen from among TeOF.sub.5.sup.- or SeOF.sub.5.sup.-.