A metal detector includes a balanced coil system with a transmitter coil connected to a transmitter unit, which provides a transmitter signal (s1) with at least one fixed/selectable transmitter frequency or a waveform having at least two different transmitter frequencies. First and a second receiver coils provide output signals to a receiver unit, which can include first and second phase detectors in which the output signals are compared with reference signals that correspond to the at least one transmitter frequency and are offset to each other in phase in order to produce in-phase components and quadrature components, which are forwarded to a signal processing unit to suppress signal components originating from goods or noise, and to process signal components originating from metal contaminants.

A high-precision magnetometer based on a miniature Penning trap is used to measure high magnetic field strengths with very high accuracy. Due to the high precision of the developed miniature charged particle trap, magnetic field strengths can be measured with an accuracy of 1 part per million or greater, including up to and above 1 part per billion. The charged particle trap has been configured to operate with such precision in environments of high radiation, e.g., 1 MGy or above.

A high-precision magnetometer based on a miniature Penning trap is used to measure high magnetic field strengths with very high accuracy. Due to the high precision of the developed miniature charged particle trap, magnetic field strengths can be measured with an accuracy of 1 part per million or greater, including up to and above 1 part per billion. The charged particle trap has been configured to operate with such precision in environments of high radiation, e.g., 1 MGy or above.

A high-precision magnetometer based on a miniature Penning trap is used to measure high magnetic field strengths with very high accuracy. Due to the high precision of the developed miniature charged particle trap, magnetic field strengths can be measured with an accuracy of 1 part per million or greater, including up to and above 1 part per billion. The charged particle trap has been configured to operate with such precision in environments of high radiation, e.g., 1 MGy or above.

A high-precision magnetometer based on a miniature Penning trap is used to measure high magnetic field strengths with very high accuracy. Due to the high precision of the developed miniature charged particle trap, magnetic field strengths can be measured with an accuracy of 1 part per million or greater, including up to and above 1 part per billion. The charged particle trap has been configured to operate with such precision in environments of high radiation, e.g., 1 MGy or above.

A microfabricated sensor includes a sensor cell with a cell body and a window attached to the cell body. A sensor cavity containing sensor fluid material is located in cell body, open to the window. A signal path extends from a signal emitter outside the sensor cell, through the window and sensor cavity, and to a signal detector. The sensor cell may have an asymmetric thermal configuration, conducive to developing a temperature gradient in the sensor cell. One or more heaters are disposed on the sensor cell, possibly in an asymmetric configuration. Power is applied to the heaters, possibly asymmetrically, so as to develop a temperature gradient in the sensor cell with a low temperature region in the sensor cell, sufficient to condense the sensor fluid in the low temperature region, outside of the signal path.

A microfabricated sensor includes a sensor cell with a cell body and a window attached to the cell body. A sensor cavity containing sensor fluid material is located in cell body, open to the window. A signal path extends from a signal emitter outside the sensor cell, through the window and sensor cavity, and to a signal detector. The sensor cell may have an asymmetric thermal configuration, conducive to developing a temperature gradient in the sensor cell. One or more heaters are disposed on the sensor cell, possibly in an asymmetric configuration. Power is applied to the heaters, possibly asymmetrically, so as to develop a temperature gradient in the sensor cell with a low temperature region in the sensor cell, sufficient to condense the sensor fluid in the low temperature region, outside of the signal path.

A method for providing a miniature vector magnetometer includes embedding a micron-sized diamond nitrogen-vacancy (DNV) crystal into a bonding material. The bonding material including the embedded micron-sized DNV crystal is cured to form a micro-DNV sensor. A micro-DNV assembly is formed by integrating the micro-DNV sensor with a micro-radio-frequency (RF) source, a micron-sized light source, a reference bias magnet, and one or more micro-photo detectors. The micro-DNV assembly is operable to perform vector magnetometry when positioned in an external magnetic field.

A method for providing a miniature vector magnetometer includes embedding a micron-sized diamond nitrogen-vacancy (DNV) crystal into a bonding material. The bonding material including the embedded micron-sized DNV crystal is cured to form a micro-DNV sensor. A micro-DNV assembly is formed by integrating the micro-DNV sensor with a micro-radio-frequency (RF) source, a micron-sized light source, a reference bias magnet, and one or more micro-photo detectors. The micro-DNV assembly is operable to perform vector magnetometry when positioned in an external magnetic field.

In a method, device and magnetic resonance (MR) system for determining a system frequency in MR imaging, a frequency spectrum of a region under examination is acquired. A cost function (FOM) is determined that encompasses the difference between a parameterized model function having assigned parameters that is to be optimized, and the acquired frequency spectrum. The cost function is subsequently minimized. Furthermore, the parameters of the optimized parameterized model function assigned to the determined minimum are determined and the system frequency is calculated on the basis of the determined parameters.