Abstract: A method for nuclear magnetic resonance (NMR) spectroscopy of a sample comprises preparation of the sample and carrying out an NMR spectroscopy measurement. Preparation includes excitation of long lived coherences (LLC) between the singlet state S0 and the central triplet state T0 of nuclei of the sample. The thermal equilibrium Boltzmann distribution (Iz+Sz) is thereby transformed into a difference (Iz?Sz), which is flipped to the transverse plane, and irradiation of the sample with an rf-field is initiated. The LLC is sustained by maintaining the rf-irradiation during an interval t1 and the LLC is converted into observable magnetisation by interrupting the rf-irradiation. The method allows nuclear magnetic resonance spectroscopy measurements with improved spectral resolution.

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 sample frame (30; 81) for preparing a plurality of sample vessels (41, 42), in particular sample tubes, having a plurality of retainers, in each of which a sample vessel (41, 42) is situated, is characterized in that the sample vessels (41, 42) each have a cap (43, 44), which is put over the open end of the sample vessel (41, 42), the cap (41, 42) having a drilled hole (53, 54), through which the interior of the sample vessel (41, 42) is accessible, the sample frame (30; 81) has a removable cover plate (8), whose bottom side faces toward the caps (43, 44) of the sample vessels (41, 42) in the put-on state of the cover plate (8), and the cover plate (8) has an approximately funnel-shaped depression (11, 71) on the top side for each retainer, in whose center a through opening (57) through the cover plate (8) is provided, the through opening (57) aligning with the drilled hole (53, 54) of a cap (43, 44) of a sample vessel (41, 42) retained underneath when the cover plate (8) is put on.

Abstract: A device for monitoring a living object during a magnetic resonance (MRI) experiment in an MRI tomograph, wherein the device comprises one or more individual electrodes which are connected in an electrically conducting fashion to the living object to be examined, and are connected to a monitoring device via signal lines, wherein each signal line comprises individual parts that are electrically connected to each other via impedances. The eigenfrequencies of these parts are higher than the NMR measuring frequency, preferably more than twice as high, and the parts are electrically connected to each other via frequency-dependent impedances Zn. The electro-magnetic coupling from the RF antenna and the gradient coils to the signal lines can thereby also be minimized in a simple fashion.

Abstract: A method for determining the spatial distribution of the magnitude of the radio frequency transmission field B1 in a magnetic resonance imaging apparatus, wherein the method comprises performing an MRI experiment in which a B1-sensitive complex image (SI) of a sample is obtained, wherein the phase distribution within the B1-sensitive complex image (SI) depends on the spatial distribution of the magnitude of the field B1. For establishing the dependency of the phase distribution within the B1-sensitive complex image (SI) on the spatial distribution of the field B1, one or more adiabatic RF pulses are applied. The method provides a simple procedure for mapping the B1 field of a magnetic resonance imaging apparatus with an improved accuracy and a wider measurement range.

Abstract: A cryostat (1) with a magnet coil system including superconductors for the production of a magnet field B0 in a measuring volume (3) has a plurality of radially nested solenoid-shaped coil sections (4, 5, 6) and which are electrically connected in series, at least one of which being an LTS section (5, 6) with a conventional low temperature superconductor (LTS) and at least one of which being an HTS section (4) including a high temperature superconductor (HTS), wherein the magnet coil system is located in a helium tank (9) of the cryostat (1) along with liquid helium at a helium temperature TL. The apparatus is characterized in that a chamber (11) is provided within which the HTS sections (4) are held having an internal portion with a sufficiently low pressure such that helium located therein at a temperature of TL is gaseous. The cryostat in accordance with the invention can be utilized to maintain HTS coil sections over a long period of time in a reliable fashion.

Abstract: A cryostat (1) with a magnet coil system including superconductors for the production of a magnet field B0 in a measuring volume (3) has a plurality of radially nested solenoid-shaped coil sections (4, 5, 6) which are electrically connected in series, at least one of which being an LTS section (5, 6) with a conventional low temperature superconductor (LTS) and at least one of which being an HTS section (4) including a high temperature superconductor (HTS), wherein the LTS section (5, 6) is located in a first helium tank (9) of the cryostat (1) along with liquid helium at a helium temperature TL<4 K. The apparatus is characterized in that the HTS section (4) is disposed radially within the LTS section (5, 6) in a separate helium tank (19) of the cryostat (1) having normal liquid helium and is separated from the LTS section (5, 6) by means of at least one wall disposed between the two helium tanks.

Abstract: A fully automatic, parameter free MR interpretation system is based on human logic emulation. Information is derived mainly from an MR spectrum with maximum confidence and in a similar way as a human expert. This is achieved by the combination of different expert systems that interpret certain MR spectral features as well as features from a proposed structure. The expert systems are dynamically linked to each other and the analysis is performed iteratively in all directions in a way that the expert systems can utilize all of the interpretations of all expert systems at all times. The expert system may generate not just a single result but rather lists of probability weighted hypotheses.

Abstract: An automated screening device that performs standardized system suitability tests and evaluations and measures components of a submitted sample to assist in the quality control screening of raw materials, ingredients, pharmaceuticals, chemicals, polymers, food products, petroleum and many other materials. After determining the performance suitability of an NMR spectrometer, the system permits samples to be submitted for screening. An NMR spectrum of a sample is acquired and a qualitative analysis unit identifies at least one reference NMR spectrum corresponding a compound present in the sample and a quantitative analysis unit integrates relative signal intensity signals of the sample spectrum in regions of peak intensity in the one reference NMR spectrum and compares integration results to a number of atoms in each region in order to confirm identification of the compound.

Abstract: A magnetic field gradient generating system for a NMR system, includes at least one set of gradient coils, preferably arranged according to three axes of a spatial referential system, and a controlled power supplying unit for the gradient coils, the power supplying unit including, for each gradient coil, a converter/amplifier module, the modules being fed with pulse sequences of digital gradient data provided as word streams by an adapted gradient data generator according to a pulse program, each arrangement of a gradient coil and a converter/amplifier module forming a gradient channel. The power supplying unit also includes an automatic blanking system which scans the gradient data words sent to the [converter/amplifier] modules and, according to sensed values, selectively delivers blanking signals to be applied to the modules in order to disable the power stages of their respective amplifiers connected to the gradient coils, when no current is to be fed to the coils.

Abstract: A superconducting magnet configuration (4; 14) for generating a homogeneous magnetic field B0 in an examination volume (4b), has an interior radial superconducting main field coil (1) which is disposed rotationally symmetrically about an axis (z-axis) and an oppositely driven coaxial radially exterior superconducting shielding coil (2) is characterized in that the magnet configuration (4; 14) consists of the main field coil (1), the shielding coil (2), a ferromagnetic field formation device (3; 18) and a ferromagnetic shielding body (AK), wherein the ferromagnetic field formation device (3; 18) is located at the radially inside of the main field coil (1) and the ferromagnetic shielding device (AK) surrounds the main field coil (1) and the shielding coil (2) in a radial and axial direction, the main field coil (1) consisting of an unstructured solenoid coil or of several radially nested unstructured solenoid coils (15, 16) which are driven in the same direction, the axial extent Labs of the shielding coil (2)

Abstract: A transport device for conveying an object to be transported (18) between an input point (A) and a supply point (Z), where the object to be transported (18) can be supplied to an RT tube (4) of a cryostat (1), wherein the input point (A) is both horizontally and also vertically spaced apart from the supply point (Z), wherein a transport tube (14) is provided for pneumatically conveying the object to be transported within the transport tube (14) from a first transfer point (B) to a second transfer point (C), is characterized in that the transport tube (14) is vertically arranged, a first transport container (TB1) and a second transport container (TB2) are provided for receiving the object to be transported (18), a first transfer device is disposed between the input point (A) and the first transfer point (B), and a second transfer device is provided between the second transfer point (C) and the supply point (Z).

Abstract: Each NMR rotor bearing in an NMR magic angle spinning assembly is constructed of a porous ceramic material and has no inlet channels or nozzles. Instead, pressurized gas is forced through pores in the bearing ceramic material from an annular groove at the bearing periphery to the central aperture. Since the pores are small and very numerous, the gas pressure is effectively balanced around the periphery of the central aperture. In addition, if contaminants block one or more pores during operation, the pores are so numerous that the balanced pressure can still be maintained in the central aperture, thereby preventing an imbalance that could destroy the rotor.

Abstract: A nuclear magnetic resonance (NMR) magic angle spinning (MAS) probe head (1; 61) for measuring a measuring substance in an MAS rotor (21a-21c), comprises a bottom box (3) and a tube (2) mounted to the bottom box (3) and projecting from the bottom box, wherein, in the area of the end (5) of the tube (2) facing away from the bottom box (3), an MAS stator (7; 62) is disposed within the tube (2) for receiving an MAS rotor (21a-21c), and with a pneumatic sample changing system for supplying and discharging an MAS rotor (21a-21c) to/from the MAS stator (7; 62). A transport conduit (10) is provided for pneumatically transferring an MAS rotor (21a-21c) within the transport conduit (10), wherein the transport conduit (10) extends in the inside of the tube (2) from the bottom box (3) to the MAS stator (7; 62). The probe head realizes fast change between different MAS rotors and facilitates RF shielding and keeping of defined extreme temperature conditions.

Abstract: A monitoring cell, used to perform a measurement in an NMR spectrometer of a reaction fluid produced by a reaction vessel, has a body having inlet and outlet transport coaxial capillaries for transporting the reaction fluid between the body and the reaction vessel. Cooling lines are also positioned coaxially with the transport capillaries to transport cooling liquid between the body and the reaction vessel. The cell further has a hollow sample probe for insertion into the NMR spectrometer and a coupler section that removably connects the sample probe to the body so that the inlet transport capillary extends through the body into the interior of the sample probe and the outlet transport capillary is sealed to the sample probe to allow reaction fluid that enters the sample probe via the inlet transport capillary to exit the sample probe via the outlet transport capillary.

Abstract: A sample tube for an NMR probe head, which extends along a z axis and has an internal cavity that extends in an axial direction of the z axis, is open to the outside at the axially upper end, is closed at the axially lower end and contains a liquid NMR sample substance during operation, wherein the cross-sectional surface of this cavity extending perpendicularly to the z axis and parallel to the xy coordinate plane has an elongated shape in the direction of the x axis with maximum dimensions a in the y direction and b in the x direction, wherein a<b, is characterized in that the cross-sectional surface of the sample tube, which extends perpendicularly to the z axis and is parallel to the xy coordinate plane has a circular outer shape. Sample tubes of this type provide a particularly large signal-to-noise ratio, can be easily inserted into a conventional cryogenic probe head and be axially and radially positioned therein by existing precision centering devices.

Abstract: An actively shielded superconducting magnet configuration (M1; M2; M3; 14) for generating a homogeneous magnetic field B0 in a volume under investigation (4b) has a radially inner superconducting main field coil (1) which is disposed rotationally symmetrically about an axis (z axis) and a coaxial radially outer superconducting shielding coil (2) which is operated in an opposite direction. The magnet configuration consists of the main field coil, the shielding coil and a ferromagnetic field-shaping device (3; 18), wherein the ferromagnetic field-shaping device is disposed radially inside the main field coil. The main field coil consists of an unstructured solenoid coil or of several radially nested unstructured solenoid coils (15, 16) which are operated in the same direction. An extension Labs of the shielding coil in the axial direction is smaller than the extension Lhaupt of the main field coil in the axial direction.

Abstract: An apparatus for DNP-NMR measurement on a sample, with a magnet configuration for producing a magnetic field in a first working volume and in, a second working volume with a magnetic field gradient in the direction of an axis (z) which extends through the second working volume, with a device for measuring MR signals, with a DNP excitation device, and with a positioning mechanism for transferring the sample, is characterized in that, near the second working volume, a compensation configuration made of magnetic material is mounted that, in the operating condition of the magnet configuration, produces a magnetic field gradient in the direction of the axis (z) in the second working volume that is between ?90% and ?110% of the magnetic field gradient of the same order of the stray field of the magnet configuration.

Abstract: A method and device have an electrode rod (1; 21) for a pH meter. The electrode rod (1; 21) has a measuring end (2; 22) for immersion into a liquid test sample (31), wherein the measuring end (2; 22) has a pH measuring element, and wherein electrical feed lines (5) in the electrode rod (1; 21) extend towards the pH measuring element. A plurality of capillaries (8, 9, 10; 23) for feeding liquids and gas into the test sample (31) extend in the electrode rod (1; 21) and have outlet openings (11, 12, 13; 24) in the area of the measuring end (2; 22). The method and device facilitate and accelerate preparation of liquid test samples and adjustment of a pH value for small amounts of test samples or narrow sample containers in NMR spectroscopy applications.

Abstract: A nuclear magnetic resonance (NMR) apparatus (10) comprises a superconducting main field magnet coil system (14) which generates a homogeneous magnetic field of at least 3T, and a gradient coil system (15) which generates a gradient strength of at least 10 mTm?1, with a slew rate of at least 100 Tm?1s?1, wherein the main field magnet coil system (14) is arranged in a cryostat (12) with liquid helium and a refrigerator (16) in the form of a pulse tube cooler or a Gifford-McMahon cooler, and wherein an evaporation line (17a, 27a, 37a) is provided for helium that might evaporate from the cryostat. In all states of operation of the NMR apparatus (10) without gradient switching, the refrigerator provides a cooling capacity which is at least 0.