Abstract: A method for calculating the shape of a band-shaped superconductor (3) of a solenoid-shaped coil section of a high-field magnet coil (1) in a transfer region (5) is characterized in that the band-shaped superconductor (3) is changed in the transfer region from a first orientation (3a) tangentially flatly abutting on the surface of a cylindrical coil body (2) and substantially perpendicular to the longitudinal direction of the cylindrical coil body (2) to a second orientation (3b) with its narrow side seating on the surface of the cylindrical coil body and parallel to the longitudinal direction (or vice versa).

Abstract: A flat multi-layer arrangement (1; 1a–1f) of superconducting wires (4,5) with normally conducting substrate (17) and at least one fiber (16) which is electrically conductingly connected to the substrate (17) and is superconducting under predetermined operating conditions is characterized in that the superconducting wires (4, 5) in a respective layer (2, 3; 22, 23) are substantially disposed such that they do not cross. A resistive electric contact is provided between the superconducting wires (4, 5) of different layers (2,3; 22, 23) and the superconducting wires (4, 5) of at least two neighboring layers (2, 3; 22, 23) do cross, wherein no closed superconducting loops are present in the arrangement (1; 1a–1f). This arrangement permits shielding of the working volume of a magnet coil arrangement against low-frequency stray fields in an efficient and reliable manner.

Abstract: The system describes a means and a method for stabilizing the magnetic field generated in the measuring volume of a high-resolution magnetic resonance spectrometer having an actively shielded magnet coil (4) which is located in a cryostat (2) and which is superconductingly short-circuited. The system comprises a compensation coil (12) which is decoupled from the magnet coil (4), and is disposed on the shielding coil (4b) of the magnet coil (4).

Abstract: A probe head for nuclear magnetic resonance measurements comprises a sample holder having a stator and a rotor. The rotor is journalled for rotation about an axis of rotation within the stator. It is adapted for receiving a sample substance. The axis of rotation is inclined by an angle with respect to a longitudinal axis of the probe head. The stator is configured as a dielectric resonator.

Abstract: A superconducting magnet system with a superconducting magnet coil system disposed in a cryogenic fluid tank (2) of a cryostat (1), and a refrigerator (6) for cooling the cryogenic fluid that cools the magnet, is characterized in that a radiation shield (5; 21; 31; 41; 51) is provided which separates a refrigerator space (4) from the cryogenic fluid tank (2), wherein the entire cooling region (9) of the refrigerator (6) is disposed in the refrigerator space (4), and wherein the radiation shield (5; 21; 31; 41; 51) has openings (11; 22; 44, 45; 53) for gas or fluid exchange between the refrigerator space (4) and the cryogenic fluid tank (2). Should the refrigerator fail, the thermal input into the cryostat is reduced, and the safety of the maintenance staff is improved in case of a quench.

Abstract: A superconducting magnet configuration with a magnet coil (1) of inductance L which is disposed in a cryostat (7) at a cryogenic temperature, for generating a temporally stable magnetic field, in a working volume, which is suitable for NMR measurements, and with current feed lines to an external current source (3) via which a current of a current strength IPS can be supplied, wherein, at a cryogenic temperature, the magnet coil (1) can be exclusively short-circuited via a switch (5), is characterized in that the switch (5) is normally conducting and comprises a mechanically operable bridge (6) with an ohmic resistance R1 which can be predetermined. The inventive magnet configuration ensures straightforward stable permanent operation via a mains supply even at high currents (>1000A) and also effective discharge of the energy released during a quench.

Abstract: A magnetic resonance apparatus comprising a superconducting magnet coil which is disposed in a cryostat, and a refrigerator for cooling the magnet coil, which comprises a compressor for compressing a working gas, and a high-pressure line and a low-pressure line between the compressor and a control valve, which periodically connects the high-pressure line and the low-pressure line to a connecting line from the control valve to a cold head of the refrigerator, thereby generating pressure pulses via the connected working gas, wherein the control valve is mechanically rigidly connected to the cryostat, is characterized in that one pressure reservoir is provided in the high-pressure line and/or in the low pressure line, which is mechanically rigidly connected to the cryostat and which is connected to the compressor via a mechanically flexible line section.

Abstract: An actively shielded superconducting magnet coil system (1) for generating a magnetic field in a working volume (6), which is rotationally symmetric about a z-axis, comprising a radially inner main field winding (5) and a radially outer shielding winding (7), and an electrically highly conductive shielding cylinder (radially inner shielding cylinder) (8a/8b) which is disposed radially inside the main field winding (5) or between main field winding (5) and the shielding winding (7) is characterized in that at least one further electrically highly conductive shielding cylinder (9) is disposed radially outside the shielding winding (7). The inventive magnet coil system prevents generation of a fringe field flash in the outer region of the magnet coil system in case of a quench.

Abstract: A method and an apparatus serve the purpose of determining the fat or oil content of a sample. The sample is dried under the action of a microwave field and is examined under the action of a radio-frequency signal and of a constant magnetic field by means of nuclear magnetic resonance. The sample is exposed to the microwave field, the radio-frequency signal and the magnetic field at the same measuring place in a common measuring chamber. The apparatus has a microwave source for drying the sample, a magnetic system for generating a nuclear magnetic resonance magnetic field in the sample, and a nuclear magnetic resonance measuring arrangement for irradiating radio-frequency signals into the sample and for receiving excited nuclear magnetic resonance signals from the sample. The microwave source, the magnetic system and the nuclear magnetic resonance measuring arrangement are connected to a common measuring chamber in which the sample is located.

Abstract: A superconducting magnet coil configuration comprising at least one section of a superconducting strip conductor, which is continuously wound in a cylindrical winding chamber (1) between two end flanges (2, 3) in several solenoid-like layers is characterized in that the section comprises an axial region of reduced current density (=notch region (10)), and the winding layers (6, 9) have hollow cylindrical blind regions (4a, 4b, 4c) which are filled with filler and which have different axial lengths, and radially sequential blind regions (4a, 4b, 4c) each alternately abut one of the two end flanges (2, 3) and are each radially separated from each other by at least one continuous winding layer (7), wherein the axial overlapping region of the blind regions (4a, 4b, 4c) forms the notch region (10). The inventive device thereby realizes a magnet coil configuration comprising a strip conductor which has a notch region for correcting inhomogeneities, wherein the mechanical load on the strip conductor is minimized.

Abstract: The invention concerns a superconducting high-field magnet system (1) for a high-resolution magnetic resonance spectrometer, comprising a magnet coil (4) which is superconductingly short-circuited during operation, and generates a homogeneous temporally stable magnetic field during operation that meets the requirements for taking a high-resolution magnetic resonance spectrum. The magnet coil (4) comprises an LTS partial coil (4b, 4c) and an HTS partial coil (4a, 4d). The LTS partial coil (4b, 4c) can be separately short-circuited in a pure LTS circuit (14b) via an LTS switch (15b), and the HTS partial coil (4a, 4d) can be separately short-circuited in a pure HTS circuit (14) via an HTS switch (15a) and both partial coils (4a, 4d; 4b, 4c) are connected via an LTS-HTS joint (20) and are charged by the same power supply.

Abstract: A probe head for nuclear magnetic resonance measurements in an area of a surface of a measuring object is disclosed. The probe head comprises first means for generating a static magnetic field extending at least partially parallel to the surface, second means for generating a radio frequency magnetic field having components extending perpendicular to the surface, and third means for amplifying a radio frequency magnetic field effective within the measuring object. The third means are configured as an aperture and are located between the second means and the surface.

Abstract: A magnetic resonance apparatus comprising a superconducting magnet coil disposed in a cryostat, and a refrigerator for cooling same comprising a compressor (1) for compressing a working gas, and a high-pressure line (2) and a low-pressure line (3) disposed between the compressor (1) and a control valve (5), which periodically connects the high-pressure line (2) and the low-pressure line (3) to at least one connecting line (6) between the control valve (5) and a cold head (4) of the refrigerator, thereby producing pressure pulses through the switched working gas, wherein the control valve (5) and/or connecting line (6) and cold head (4) components are rigidly mechanically coupled to the cryostat, is characterized in that at least one of the above-mentioned lines (2, 3, 6) is branched on the compressor side upstream of the rigidly coupled components, and is symmetrically joined at one of the coupled components in such a manner that the pressure pulses through the working gas are vectorially compensated for at t

Abstract: A probe head for nuclear magnetic resonance measurements is disclosed in which at least a first kind of nuclei with a first, higher resonance frequency and a second kind of nuclei with a second, lower resonance frequency are excited within a magnetic field. The probe head comprises a first input/output terminal for the higher resonance frequency and a second input/output terminal for the lower resonance frequency. A measuring coil cooperates with a sample. The measuring coil has a first terminal end and a second terminal end. The first terminal end is coupled to the first input/output terminal and the second terminal end is coupled to the second input/output terminal. A stop circuit tuned to signals of the higher resonance frequency is arranged between the second terminal end and the second input/output terminal. The stop circuit, further, comprises a line having a length equalling a quarter wave length of the higher resonance frequency. The first line is arranged in series with the measuring coil.

Abstract: An apparatus for determining a quantitative property of a sample substance by means of magnetic resonance is disclosed. The apparatus comprises a conveyor for conveying sample containers containing the sample substance through a measuring station. The measuring station comprises a magnet system for generating a constant magnetic field of high homogeneity. The measuring station, further, comprises a probe head adapted for letting sample containers be conveyed therethrough and for generating a high frequency magnetic field. A magnetic resonance measuring unit determines the quantitative property of the sample substance contained in the probe head. The probe head excites and detects, resp., the magnetic resonance essentially only within that section of the sample container which contains the sample substance. The probe head comprises a split-ring resonator which, as seen in a conveying direction of the conveyor, has a passage cross-section for letting run the sample containers therethrough.

Abstract: A superconducting magnet coil configuration has at least one section containing a superconducting strip conductor which is wound in several layers like a solenoid in a cylindrical winding chamber (1) between two end flanges (2, 3), characterized in that the radially innermost layers of the section consist of metallic low-temperature superconductors (LTS) (LTS layers (8)) and radially adjacent layers of the section are formed from high-temperature superconductor (HTS) material (HTS layers (9)). The invention proposes a magnet coil configuration using HTS material which has a notch structure for correcting inhomogeneities and homogenizing a compact high-field magnet, wherein the mechanical load on the HTS strip conductor is minimized.

Abstract: The invention refers to a method of resonance spectroscopy for the analysis of statistical properties of samples, comprising the following steps: a) recording of a complex resonance frequency spectrum of each sample by means of phase sensitive quadrature detection; b) numerical differentiation of the recorded complex resonance frequency spectra versus frequency; c) determination of the absolute value of each differentiated complex resonance frequency spectrum (=fingerprint); d) allocation of each fingerprint to a point of a multidimensional point set; and e) performing a pattern analysis of the generated points for characterizing the statistical properties of the samples. The inventive method tolerates unintended variances of measurement in the recorded resonance frequency spectra, in particular caused by phase errors, and allows reliable automated spectral analysis.

Abstract: An NMR apparatus comprising a superconducting magnet coil system, in particular, an NMR spectrometer, with a cryostat which comprises an outer shell and a helium tank which contains the magnet coil system, and with an NMR probe head which is disposed in a room temperature bore of the cryostat and which contains a cooled RF resonator for receiving NMR signals from a sample to be examined and is cooled, together with the NMR probe head, by a cold head of a common, multi-stage, compressor-operated refrigerator, is characterized in that the cold head of the refrigerator is disposed in a neck tube, the upper end of which is connected to the outer shell of the cryostat and the lower end of which is connected to the helium tank in such a manner that the neck tube and the helium tank delimit a helium space, with at least one cooling circuit with thermally insulated transfer lines being provided between the helium space and the NMR probe head, wherein the cryogenic helium in the helium space is used as coolant for the

Abstract: A NMR method to verify the presence of organic molecular compounds consisting of repetitive occurring individual structures is presented. The method comprises the steps of assigning structure codes to the selected compounds, in accordance with the respective starting compounds used, measuring multi-dimensional NMR spectra from at least some of the compounds, uniquely assigning signal groups of NMR spectra to the individual structures, checking the NMR spectra of the compounds for the presence of all assigned signal groups, and characterizing a particular compound as being TRUE if the check of its particular combination of structures yields the result that the signal groups of structures contained in its total code had been observed. The method permits rapid and accurate verification of the presence of compounds having repetitive structures such as those produced in combinatorial chemistry.

Abstract: An NMR spectrometer comprising a magnet coil system disposed in the helium tank (8) of a cryostat and an NMR probe head (4) which is disposed in a room temperature bore of the cryostat and contains a cooled RF resonator (13) for receiving NMR signals from a sample to be examined, wherein the helium tank (8) and the NMR probe head (4) are cooled by a common, multi-stage, compressor-operated refrigerator, is characterized in that the common refrigerator comprises a cold head (6) and several heat exchangers (21, 24, 25, 28, 31, 33, 34) at different temperature levels, wherein the refrigerator is disposed at a spatial separation from the cryostat in a separate, evacuated and thermally insulated housing (5), and several cooling circuits (1a, 1b, 1c, 1d, 2a, 2b, 3a, 3b) having thermally insulated transfer lines (14a, 14b, 15) are provided between the housing (5) containing the heat exchangers (21, 24, 25, 28, 31, 33, 34) and the cryostat, and also between the housing (5) and the NMR probe head (4).