Abstract: A nuclear magnetic resonance (NMR) method for singlet-state exchange NMR-spectroscopy comprises steps of excitation of single-quantum in-phase coherences, generation of single-quantum anti-phase coherences, excitation of zero-quantum coherences ZQx and/or longitudinal two-spin order 2IzSz (=“ZZ order”) using a ?/4 pulse, reversal of the sign of the zero-quantum coherences ZQx under the effect of the difference of the chemical shifts of the examined spins, transformation of the zero-quantum coherences ZQx and/or longitudinal two-spin ZZ order into singlet-state populations by means of RF irradiation during a mixing period ?m, reconversion of the singlet-state populations remaining at the end of the mixing period ?m into zero-quantum coherences ZQx and/or ZZ order, reversal of the sign of the zero-quantum coherences ZQx under the effect of the difference of the chemical shifts of the examined spins, and reconversion of zero-quantum coherences ZQx and/or ZZ order into single-quantum anti-phase coherences.

Abstract: A flow-through microfluidic NMR-chip comprising a substrate (5) which is planar in an yz-plane with a sample chamber (2) within the substrate (5), the sample chamber (2) being elongated and having walls which run parallel to the z-direction, the substrate (5) having a thickness in x-direction of a Cartesian xyz-coordinate system between 100 ?m and 2 mm, and at least one planar receiving and/or transmission coil (1, 1?) with conductor sections (11) the coil (1, 1?) being arranged at least on one planar surface of the substrate (5), wherein the extension of the sample chamber (2) along the z-direction exceeds the extension of the coil (1) along the z-direction is characterized in that the extension of the coil (1, 1?) along the z-direction is larger than its extension along the y-direction. The inventive NMR-chip facilitated NMR-spectroscopic measurements with improved resolution, sensitivity as well as B1 homogeneity.

Abstract: A method for homogenizing a static magnetic field with a magnetic field distribution B0(r) for nuclear magnetic resonance spectroscopy by adjusting the currents Ci through the shim coils, thus creating spatial field distributions Ci·Si(r), where r stands for one, two, or three of the spatial dimensions x, y, and z, and said magnetic field distribution B0(r) has only a field component along z, in a working volume of a magnetic resonance apparatus with one or more radio frequency (=RF) coils (5) for inducing RF pulses and receiving RF signals within a working volume, said RF coils having a spatial sensitivity distribution of magnitudes B1k(r), and with shim coils (6) for homogenizing the magnetic field within the working volume, said shim coils (6) being characterized by their magnetic field distributions per unit current Si(r) and having components only along z, includes the following steps: (a) Mapping the magnetic field distribution B0(r) of the main magnetic field, (b) calculating a simulated spectrum IS

Abstract: A magnet coil system (2) which is at least partially superconducting at a cryogenic temperature, comprising at least two partial coils (3, 4, 5) which are connected in series and are each bridged by a superconducting switch (6, 7, 8), such that the partial coils form independent electric loops (11, 12, 13) when the superconducting switches (6, 7, 8) are closed, is characterized in that two electric loops (11, 12) have a common section and a flux pump (10) is provided which is circuited in the common section (14) of the electric loops (11, 12) of two partial coils (3, 4), wherein the sum of the currents of the two partial coils (3, 4) flows through the flux pump (10) in the operating state. In this fashion, the drifts of two independent electric loops can be compensated for with a few devices.

Abstract: A magnet arrangement (M, M?, M?, M??) for generating a magnetic field in the direction of a z-axis in a working volume (V) disposed on the z-axis about z=0, with a magnet coil system (A, A?, A?, A??) which comprises one or more superconducting magnet partial coil systems (A1, A1?, A1?, A1??, A2??, . . ., An??), each forming superconductingly short-circuited current paths in the operating state, and with a further coil system (C, C?, C?, C??) which can be charged or discharged independently of the magnet coil system (A, A?, A?, A??) and comprises a first and a second partial coil system (C1, C2, C1? C2?, C1?, C2?, C1??, C2??), wherein the first partial coil system (C1, C1?, C1?, C1??) and the second partial coil system (C2, C2?, C2?, C2??) each comprise at least one coil, wherein all coils of the further coil system (C, C?, C?, C??) are connected in series, wherein gCeff,diamag>0.1 mT/A, is characterized in that gC1eff,diamag>0.1 mT/A, gC2eff,diamag>0.

Abstract: A radio-frequency (RF) resonator system, in particular, for a magnetic resonance (MR) probe, comprising at least one RF resonator with a substrate, on which a conductive structure is applied, wherein the conductive structure comprises regions of capacitive and inductive elements, is characterized in that the conductive structure is coated at least in the regions of the capacitive elements with at least one dielectric layer that covers the regions of the capacitive elements at least partially, wherein the local thickness of at least one of the dielectric layers is set in dependence on the resonance frequency of the uncoated RF resonator, on a defined resonance frequency of the resonator once it is coated, on the dielectric constant of the substrate and on the dielectric constant of the materials of the dielectric layers.

Abstract: A magnetic resonance probe head (40) comprises a vacuum container (43) in which several RF resonator coils (31, 32; 51-54, 61-64) are disposed that can be cryogenically cooled and which are each designed as planar coils disposed parallel to a z direction. All of the RF resonator coils (31, 32; 51-54, 61-64) have a larger extension in an x direction (RSx) than in a y direction (RSy), wherein the x, y, z directions form a rectangular coordinate system. A central tube block (33; 81; 111; 121; 171; 181) is disposed between the RF resonator coils (31, 32; 51-54, 61-64) and has a recess (34, 112, 122) for a test sample (35), which is elongated in the z direction. The central tube block (33; 81; 111; 121; 171; 181) partially delimits the vacuum container and the recess (34, 112, 122) is disposed outside of the vacuum container (43).

Abstract: A superconductive element containing Nb3Sn, in particular a multifilament wire, comprising at least one superconductive filament (8) which is obtained by a solid state diffusion reaction from a preliminary filament structure (1), said preliminary filament structure (1) containing an elongated hollow pipe (2) having an inner surface (3) and an outer surface (4), wherein said hollow pipe (2) consists of Nb or an Nb alloy, in particular NbTa, wherein the outer surface (4) is in close contact with a surrounding bronze matrix (5) containing Cu and Sn, and wherein the inner surface (3) is in close contact with an inner bronze matrix (5) also containing Cu and Sn, is characterized in that the inner bronze matrix (5) of the preliminary filament structure (1) encloses in its central region an elongated core (6) consisting of a metallic material, said metallic material having at room temperature (=RT) a thermal expansion coefficient ?core<17*10?6K?1, preferably ?core?8*10?6 K?1, said metallic material having at RT a

Abstract: A cryostat configuration comprising an outer shell and a cryocontainer (2) for cryogenic fluid installed therein, wherein the cryocontainer (2) is connected to the outer shell via at least two suspension tubes (16), and with a neck tube (1) whose upper warm end is connected to the outer shell and whose lower cold end is connected to the cryocontainer (2) and into which a cold head (3) of a multi-stage cryocooler is installed, wherein the outer shell, the cryocontainer (2), the suspension tubes (16) and the neck tube (1) delimit an evacuated space, and wherein the cryocontainer (2) is moreover surrounded by at least one radiation shield which is connected to the suspension tubes (16) and optionally to the neck tube (1) of the cryocontainer (2) in a thermally conducting fashion, is characterized by a seal which can be manually and/or automatically actuated to separate the cold end of the neck tube (1) from the cryocontainer (2) in such a manner that fluid flow between the cryocontainer (2) and the neck tube (1)

Abstract: A magnetic resonance (MR) probe head comprises a detecting device with at least one antenna system which is cryogenically cooled by a cooling device, and a cooled preamplifier in a preamplifier housing which is spatially separated from the detecting device, and a thermally insulating connecting means via which the detecting device and the preamplifier housing are connected, wherein the connecting means comprises at least one cooling line for supplying and/or returning a cooling fluid, and with at least one RF line for transmitting the electric signals. The connecting means is implemented as a mechanically flexible connecting line with mechanically flexible RF lines and cooling lines disposed therein. The MR probe head is easy to handle and can be highly sensitive, wherein the detecting device can be quickly installed, removed and put into operation.

Abstract: A method for producing a superconductive element, in particular a multifilament wire, starting from a composite (1) comprising a bronze matrix containing Cu and Sn, in which at least one elongated structure containing Nb or an Nb alloy, in particular NbTa, is embedded, whereby in a first step the composite is extruded at a temperature between 300° C. and 750° C.

Abstract: A method for producing a superconductive element, in particular a multifilament wire, starting from a composite (1) comprising a bronze matrix containing Cu and Sn, in which at least one elongated structure containing Nb or an Nb alloy, in particular NbTa, is embedded, whereby in a first step the composite is extruded at a temperature between 300° C. and 750° C.

Abstract: An NMR apparatus comprising an NMR magnet system disposed in a first cryocontainer (2) of a cryostat (9), and an NMR probe head (1), wherein the first cryocontainer (2) is installed in an evacuated outer jacket and is surrounded by a radiation shield (24) and/or a further cryocontainer (3), wherein a cooling device is provided for cooling the NMR probe head (1) and a cryocontainer (2, 3), which comprises a cold head (4, 4a, 4b, 4c) with several cold stages (12a, 12b, 12c, 18a, 18b, 18c, 19a), wherein one cold stage (12a, 12b, 12c, 18a, 18b, 18c, 19a) is connected to a heat-transferring device, and wherein a cooling circuit is provided between the cooling device and the NMR probe head (1), is characterized in that the cooling device is disposed in a separate, evacuated housing (6) which is positioned directly above the cryostat (9), wherein the heat-transferring device is inserted directly into suspension tubes (29a, 29c) of the cryocontainer (2, 3) and/or is in contact with the radiation shield (24).

Abstract: A device for compensating field disruptions in magnetic fields of electromagnets with high field homogeneity, in particular, for stabilizing the H0 field of an MR measuring system, comprising at least one field detector (31) for detecting interfering signals (Uin), at least one control loop for processing the detected interfering signals (Uin), and at least one compensation coil (34) to which the detected and processed interfering output signals (Uout) are transferred and which generates a correction field for compensating the interfering signals (Uin), is characterized in that at least one of the control loops comprises a multi-selective filter system (35) which comprises one or more parallel connected selective filter elements whose center frequencies can be tuned either once or in an adaptive fashion to the frequency values of the interfering signals (Uin) to be compensated for, wherein the outputs of these filter elements are connected to at least one of the compensation coils (34).

Abstract: A method of 2-dimensional nuclear magnetic resonance (2D-NMR) correlation spectroscopy, comprises a pulse sequence with the following steps: excitation of double quantum coherence; immediate reconversion to single transition single quantum coherence; evolution of the set of single transitions; mixing with zero quantum mixing Hamiltonian; and signal detection. The method can achieve an improved sensitivity, has a transition selectivity and suppresses diagonal peaks.

Abstract: A nuclear magnetic resonance (NMR) probe component, comprising a microfabricated planar gradient chip (1), with a substrate thickness dgc?3 mm, carrying three micromachined planar partial gradient coils (10a-10f) on each of its two outer surfaces (12a, 13a), wherein the partial gradient coils (10a-10f) of the gradient chip (1) form a three-dimensional gradient system, wherein the gradient chip (1) has a central guiding and positioning slot (15) between the two outer surfaces (12a, 13a). The probe component also has a sample chip (2) for carrying an NMR sample at a sample location, with a microfabricated planar RF coil (21), wherein the sample chip (2) fits exactly in the guiding and positioning slot (15) such that in a measurement position, the sample location coincides with the center of the gradient system. The NMR probe component has improved spatial resolution and allows good alignment of the RF coil and the gradient system.

Abstract: A magnetic resonance (MR) probe head comprises a detecting device (3) with at least one antenna system which is cryogenically cooled by a cooling device, a cooled preamplifier (16) in a preamplifier housing (15a, 15b) which is spatially separated from the detecting device (3), and a thermally insulating connecting means via which the detecting device (3) and the preamplifier housing (15a, 15b) are connected, wherein the connecting means (15c) comprises at least one cooling line (9a, 9b, 53a, 53b) for supplying and/or returning a cooling fluid, and at least one RF line (10, 52) for transmitting electric signals. The connecting means (15c), including its RF and cooling lines (10, 52, 9a, 9b, 53a, 53b), can be separated from the preamplifier housing (15a, 15b) by a coupling. The MR probe head is an open system which can be used in a universal fashion through use of different measuring inserts.

Abstract: A magnet configuration comprising a superconducting magnet coil system (M) and a current path (P) which comprises parts of the magnet coil system (M), wherein at least two electric connecting points (A1, A2, A3, A4) are disposed on the current path (P), which define a section (PA1-A2, PA2-A3, PA3-A4) within the current path (P), wherein the section (PA1-A2, PA2-A3, PA3-A4) does not comprise all parts of the magnet coil system (M) contained in the current path (P), and comprising a resistive element (WA1-A2, WA2-A3, WA3-A4) having an electric resistance value ?0, and at least two contacts (K1, K2, K3, K4), wherein the contacts (K1, K2, K3, K4) are disposed between the resistive element (WA1-A2, WA2-A3, WA3-A4) and one connecting point (A1, A2, A3, A4), is characterized in that in the superconducting state of the magnet coil system (M), an electric contact (K1, K2, K3, K4) between an electric connecting point (A1, A2, A3, A4) and a resistive element (WA1-A2, WA2-A3, WA3-A4) can be closed and opened.

Abstract: A nuclear magnetic resonance probe head comprising at least two orthogonal coil/resonator configurations A1 and A2 having different resonance frequencies, wherein at feast one of the coil/resonator configurations A1 has two saddle-shaped coils S1 and S2, wherein each coil has a window about which N windings are disposed which are connected in series, wherein N?2. Each coil S1 and S2 is formed mirror-symmetrically relative to a central plane of the respective coil, which is perpendicular to the window of the respective coil, wherein the central planes of the coils S1 and S2 are identical to minimize the electromagnetic coupling between the two coil/resonator configurations A1 and A2 at the resonance frequency of A2. The NMR probe head reduces coupling between the two coil/resonator configurations.

Abstract: A tubular capacitor with variable capacitance, including a cylindrical tube (3) of dielectric material, a metallic outer electrode (1) which surrounds the cylindrical tube (3), and an inner electrode which can axially move in the inner bore (41) of the cylindrical tube (3) and which abuts the inner bore (41), wherein the inner electrode includes a metallic rod (2; 2a; 2b; 2c), is characterized in that the metallic rod (2; 2a; 2b; 2c) is axially extended at its end (5?), located in the inner bore (41) of the cylindrical tube (3), using a rod (9; 9a; 9b; 9c) of dielectric material. The inventive tubular capacitor has an increased dielectric strength and improves the resolution of NMR spectrometers.