Abstract: A probehead of an NMR-MAS apparatus with a rotation axis (RA), which lies in an xz-plane, titled by an angle ?>0 relative to a z-axis. The angle ? is adjusted by tilting around a tilt axis (DA) parallel to the y-axis relative to a target angle ?target. An angle measurement apparatus (9) has a first sensor element (7), which, together with a second sensor element (8) generates sensor signals dependent on the amplitude B0 of the static magnetic field and the vectorial orientation between the magnetic field B0 and a sensitivity vector. Two sensitivity vectors have an angle 5°<?i<175° to the z-axis and an angle ?>10° to each other. The angle between the rotation axis and the z-axis can be measured precisely and reliably over a large range, providing a feedback signal for regulated adjustment or tracking of the angle ?.

Abstract: A probehead of an NMR-MAS apparatus includes a sample which has a rotation axis tilted by an angle ?>0 with respect to the z-axis. The angle ? can be adjusted about a target angle ?target by tilting around a tilt axis. The rotation axis has a fixed angle with respect to the probehead, and the NMR-MAS apparatus tilts at least part of the probehead to adjust the angle ?. The probehead has a support frame with an outer contour K between an upper end and a lower end. For all z between the upper end and the lower end, a cross-section S(z) of the contour K exists parallel to the xy-plane with a width Q(z) in the x-direction. The width Q(z) is smaller at points away from z=0, such that Q(z1)<Q(0) and Q(z2)<Q(0) for z1<0 and z2>0.

Abstract: A nuclear magnetic resonance coil configuration having at least one flat or cylindrical coil (18), through which current flows in operation, which coil generates a high-frequency magnetic B1 field at the location of a sample (16) which is oriented parallel to an x-axis, and which for the purpose of connection to a tuning network is connected to at least two electrical feed lines (11), through which in-phase currents flow in operation, and which generate a high-frequency magnetic B2 field in the sample (16), the orientation of which encloses an angle ? with the direction of the B1 field, is characterized in that the following applies for the angle ?: ?=180°±??, where ??<90°. In this way, a B1 field profile, which is as rectangular as possible and is particularly steep on both sides, can be generated.

Abstract: An RF resonator has a birdcage resonator with two electrically conducting ring elements (12, 33, 47) and N electrically conducting bars (11). At least one pair of electrically conducting ring segments (32a, 32b, 40, 43) forms an additional electrical connection between precisely two bars (11). The pair of ring segments (32a, 32b, 40, 43) define a current path (41, 42) with these two bars (11) which is capacitively interrupted at at least one point. The ring segments (32a, 32b, 40, 43) and the bars (11) electrically connected to the ring segments (32a, 32b, 40, 43) are disposed symmetrically with respect to the yz-plane. The field homogeneity and efficiency are thereby optimized even with frequencies that are far apart.

Abstract: A gradient coil system has a cylindrical section in a central region, which contains no conductor elements and has a maximum outer radius that is larger than a minimum inner radius of conductor elements of a main gradient coil. An outer radius of this cylindrical section is only insubstantially smaller or equal in size to a minimum inner radius of a shielding coil in this axial range. The free space in the center of the gradient coil system is used to insert a passive RF shield, whose radius in a central region becomes larger over a certain length than its radius in outer regions. The RF shield is constructed from at least three partial sections, which are electrically interconnected. The actively shielded gradient coil system maximizes the volume of the RF region without loss of gradient coil system performance.

Abstract: A method for regulating radio frequency (RF) signals in a nuclear magnetic resonance (NMR) system, comprising a spectrometer, a control loop, and an NMR probe head with RF components (BE, LE, BK), wherein the spectrometer comprises a transmitter that transmits RF signals at measuring frequencies with a transmission power (PS), the NMR probe head contains an RF oscillating circuit, and the RF oscillating circuit comprises an RF coil (LE), is characterized in that the control loop controls the duration and/or the phase and/or the power of the transmitted RF signals. Measurement of a parameter is performed by means of the NMR probe head, via which parameter the current in or the voltage across one of the RF components (BE, LE, BK) can be determined, and the transmission powers (PS) and/or the phases and/or the duration of the RF signals are regulated in dependence on the measured parameter. Any occurring losses can thereby be compensated for without reducing the pulse duration.

Abstract: An RF resonator has a birdcage resonator with two electrically conducting ring elements (12, 33, 47) and N electrically conducting bars (11). At least one pair of electrically conducting ring segments (32a, 32b, 40, 43) forms an additional electrical connection between precisely two bars (11). The pair of ring segments (32a, 32b, 40, 43) define a current path (41, 42) with these two bars (11) which is capacitively interrupted at at least one point. The ring segments (32a, 32b, 40, 43) and the bars (11) electrically connected to the ring segments (32a, 32b, 40, 43) are disposed symmetrically with respect to the yz-plane. The field homogeneity and efficiency are thereby optimized even with frequencies that are far apart.

Abstract: A method for regulating radio frequency (RF) signals in a nuclear magnetic resonance (NMR) system, comprising a spectrometer, a control loop, and an NMR probe head with RF components (BE, LE, BK), wherein the spectrometer comprises a transmitter that transmits RF signals at measuring frequencies with a transmission power (PS), the NMR probe head contains an RF oscillating circuit, and the RF oscillating circuit comprises an RF coil (LE), is characterized in that the control loop controls the duration and/or the phase and/or the power of the transmitted RF signals. Measurement of a parameter is performed by means of the NMR probe head, via which parameter the current in or the voltage across one of the RF components (BE, LE, BK) can be determined, and the transmission powers (PS) and/or the phases and/or the duration of the RF signals are regulated in dependence on the measured parameter. Any occurring losses can thereby be compensated for without reducing the pulse duration.

Abstract: A magnetic resonance (MR) detection configuration comprising at least one RF resonant circuit with an inductance, a preamplifier module and an RF receiver, wherein a reactive transformation circuit is connected between a high-impedance point of the inductance and a low-impedance connecting point of the RF resonant circuit, which acts as an impedance transformer and wherein the low-impedance connecting point is connected to the preamplifier module via an RF line having a characteristic impedance, is characterized in that at least one passive damping impedance is provided in the preamplifier module downstream of the RF line, wherein the passive damping impedance can be connected to the resonant circuit by a switching means during a damping and/or transmitting process, and wherein the respective amount of the complex reflection factor of passive damping impedance relative to the characteristic impedance of the RF line exceeds a value of 0.5.

Abstract: A nuclear magnetic resonance(=NMR) probehead, comprising N basic elements (10a, 10b, 10c), where N?2, wherein each basic element (10a, 10b, 10c) comprises a measurement sample (11) and a resonator system (12a, 12b, 12c), and wherein the N resonator systems (12a, 12b, 12c) of the N basic elements (10a, 10b, 10c) are coupled to each other, is characterized in that a coupling network for the N resonator systems (12a, 12b, 12c) is provided, with which the totality of the N resonator systems (12a, 12b, 12c) can be operated in one identical, coupled mode during transmission and reception, wherein the coupling network comprises a shared receiver circuit for the totality of the N resonator systems (12a, 12b, 12c). With the inventive NMR probehead, a better signal-to-noise ratio can be achieved in the case of lossy samples than with probeheads according to the prior art.

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 nuclear magnetic resonance(=NMR) probehead, comprising N basic elements (10a, 10b, 10c), where N?2, wherein each basic element (10a, 10b, 10c) comprises a measurement sample (11) and a resonator system (12a, 12b, 12c), and wherein the N resonator systems (12a, 12b, 12c) of the N basic elements (10a, 10b, 10c) are coupled to each other, is characterized in that a coupling network for the N resonator systems (12a, 12b, 12c) is provided, with which the totality of the N resonator systems (12a, 12b, 12c) can be operated in one identical, coupled mode during transmission and reception, wherein the coupling network comprises a shared receiver circuit for the totality of the N resonator systems (12a, 12b, 12c). With the inventive NMR probehead, a better signal-to-noise ratio can be achieved in the case of lossy samples than with probeheads according to the prior art.

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 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 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 magnetic resonance (MR) detection configuration comprising at least one RF resonant circuit (1) with an inductance (L), a preamplifier module (2) and an RF receiver (7), wherein a reactive transformation circuit is connected between a high-impedance point (M) of the inductance (L) and a low-impedance connecting point (A) of the RF resonant circuit (1), which acts as an impedance transformer and wherein the low-impedance connecting point (A) is connected to the preamplifier module (2) via an RF line (15) having a characteristic impedance RW), is characterized in that at least one passive damping impedance (ZDV, ZSV, ZDV?, ZSV?) is provided in the preamplifier module (2) downstream of the RF line (15), wherein the passive damping impedance (ZDV, ZSV, ZDV?, ZSV?) can be connected to the resonant circuit (1) by a switching means during a damping and/or transmitting process, and wherein the respective amount of the complex reflection factor of passive damping impedance (ZDV, ZSV, ZDV?, ZSV?) relative to the char

Abstract: A nuclear magnetic resonance apparatus for generating a homogeneous static magnetic field in the z-direction, comprising a coil/resonator system, a gradient system, and a shielding configuration which is positioned radially between the coil/resonator system and the gradient system, wherein the shielding configuration comprises an electrically conducting layer with a slot, wherein the electrically conducting layer is disposed about the center of the shielding configuration to be axially symmetrical with respect to the z-axis, is characterized in that, in an axial section z1<z<z2 with z2?z1>L, containing at least 90% of the magnetic field energy of the coil/resonator system, the shielding configuration comprises at least one pair of regions which have a cylinder envelope shape, wherein the regions of each pair are each defined by two respectively closed limiting lines circulating about the z-axis, and wherein the two limiting lines of each region have a mutual axial separation a ? z ? ? 2 -

Abstract: A nuclear magnetic resonance probe head comprising at least two coil/resonator configurations A1 and A2, wherein at least one of the coil/resonator configurations A1 has two saddle-shaped coils S1 and S2 (1, 2; 21; 41, 42; 53), wherein each coil (1, 2; 21; 41, 42; 53) has a window (9) about which N windings (3, 4; 26, 28, 30) are disposed which are connected in series, wherein N?2, wherein the coil/resonator configurations A1 and A2 are aligned perpendicularly to each other, and wherein the coil/resonator configurations A1 and A2 have different resonance frequencies is characterized in that each coil S1 and S2 (1, 2; 21; 41, 42; 53) is formed mirror-symmetrically relative to a central plane (5) of the respective coil (1, 2; 21; 41, 42; 53), which is perpendicular to the window (9) of the respective coil, and wherein the central planes (5) 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.

Abstract: A resonator system for generating a radio frequency (RF) magnetic field in a volume under investigation of a magnetic resonance (MR) arrangement, comprises a number N of individual resonators (2) which surround the volume under investigation and which are each disposed on a flat dielectric substrate (1) around a z-axis, wherein the individual resonators (2) have windows (8) through each of which one individual RF field is generated in the volume under investigation in single operation of the individual resonators (2) and, through cooperation among the individual resonators (2), a useful RF field (7) is generated in the volume under investigation, wherein a remote RF field (6) is asymptotically generated far outside of the resonator system, and the spatial distribution of the useful RF field (7) is substantially mirror-symmetrical relative to a first plane A which contains the z-axis, and that of the asymptotic remote RF field (6) is substantially mirror-symmetrical relative to a second plane B which contains