Abstract: An NMR probe head (1) comprising one or more HF coils (2) arranged around a vertical axis of symmetry (z), and an HF network (3) surrounded by an apparatus (4) for shielding from external HF radiation comprising an electrically conductive shielding tube (5) arranged along a z-axis and that can be moved around the HF coils and the HF network in a z direction towards a base disc (6)A shielding disc (7) is provided at an axial distance from the base disc, wherein a tensible HF seal (8) is arranged between the shielding disc and the shielding tube. When the shielding tube is in a mounted state, the HF seal, in a first mounting state, can slide over the shielding disc in an unbraced and force-free manner. When the HF seal is in a second mounting state, the HF seal is mechanically braced between the shielding disc and the shielding tube to ensure an electrically conductive connection.

Abstract: The invention relates to a hybrid medical PET-SPECT/MR imaging device comprising at least one scintillating crystal and at least one module for detecting radiation which contains at least one matrix of photodetectors and an electronics section, such that said module has a mechanical structure, the external, internal or both surfaces of which are divided into at least two sections, of which at least one is coated in graphene, and the rest in non-ferromagnetic conductive material, or all the sections are coated in graphene, and such that the coating forms a Faraday cage. The invention also relates to a shielding against radiofrequency for a medical imaging device, comprising a graphene coating, which is continuous or in bands, on all the faces of the mechanical structure of the detection module of the device, or a graphene coating, continuous or in bands, on at least one face, combined with a coating of non-ferromagnetic conductive materials on the remaining faces, and said shielding forming a Faraday cage.

Abstract: An NMR probe head with an MAS stator (1) supplied with microwave radiation from a microwave guide (9) through an opening in a coil block (2) has a microwave lens (6) and a microwave mirror (8a) on an inner side of the MAS stator. The MAS rotor (3) is surrounded by a solenoid RF coil (5) and the microwave lens is arranged and embodied in the opening of the coil block on the side facing a sample volume (4) such that the cylinder axis of the MAS rotor lies in the focus of the microwave lens. The microwave mirror is arranged on, or in, the inner wall of the MAS stator that lies opposite the microwave guide and has a cylindrical and concave structure, such that the microwave mirror focuses the microwave radiation incident from the sample volume onto the central axis of the MAS rotor.

Abstract: A device for alternating examination of a measurement object (170) by means of MPI and MRI with two magnetic field-generating elements is presented. The device is characterized by a main magnet coil system with two coaxial partial coil systems (100a1, 100a2; 100b2, 100b1) arranged mirror-symmetrically relative to a central plane running perpendicularly to the z-axis through the first volume under investigation (162). The volumes under investigation are superimposed. A polarity reversal device (190) reverses the polarity of the current through a partial coil system and the main magnet coil system generates a homogeneous magnetic field of at least sixth order in the first volume under investigation when the partial coil systems have identical polarity, and a spatially strongly varying magnetic field profile in the second volume under investigation when the polarities are opposite. Repositioning of the measurement object is thereby simplified or can even be eliminated.

Abstract: A magnetic resonance arrangement with a permanent magnet system and having magnet elements, pole piece elements and yoke elements of magnetic material arranged cylinder-symmetrically with respect to the z axis. The yoke elements have a first lid (11?) and a second lid (11?) and also a hollow cylindrical drum (12) arranged axially between the lids. The yoke elements enclose the measuring volume in the axial and radial direction. The magnet elements each include a pair of cylinder-symmetrical axial magnets (13?, 13?) and also radial magnet rings (14?, 14?). The axial magnets are each arranged axially adjoining the lids and are arranged radially within the radial magnet rings and respectively axially further away from the measuring volume than the radial magnet rings. The outer diameter of the axial magnets is less than or equal to the inner diameter of the radial magnet rings.

Abstract: A phantom system has a housing (2) with a lower part (3) having an opening in the z-direction and a cover part (4) for closing the opening of the housing (2). A first plate-shaped insert element (10a) has at least one depression (11a) for receiving a liquid substance. The lower part (3) and the cover part (4) delimit a cavity (5) with an insert area (8), which is constituted to receive the first insert element (10a). A first sealing element (14a) seals the first insert element (10a) against the cavity (5) and a fixing facility fixes the first insert element (10a) in the cavity (4) of the housing (2) in an operating state of the MPI phantom. The phantom permits good contrast in MPI, MRI, or ?CT using liquid contrast media.

Abstract: A superconducting magnet assembly includes a cryostat, a vacuum vessel and a refrigeration stage. An NMR probe using the assembly includes comprises cooled probe components, a two-stage cryocooler, and a counter flow heat exchanger. A cooling circuit guides coolant from one outlet of the counter flow heat exchanger back to an inlet of the counter flow heat exchanger via the second cooling stage, a cooled probe component, and a heat exchanger in the cryostat or a heat exchanger in a helium suspension tube. Both the intake temperature of the coolant flowing into the heat exchanger in the cryostat or in the suspension tube and the return flow temperature of the emerging coolant are at least 5 K lower than the operating temperature of the first cooling stage. Excess cooling capacity of the cryocooler reduces the evaporation rate of liquid helium or cools a superconducting magnet in a cryogen-free cryostat.

Abstract: An MAS stator (7) for an NMR-MAS probe head (1) has a bottom bearing (8) with at least one nozzle and at least one radial bearing (9a, 9b), wherein one substantially circular cylindrical MAS rotor (21c) is provided for receiving a measurement substance. The MAS rotor can be supported by compressed gas in a measurement position within the MAS stator by means of a gas supply device and can be rotated about the cylinder axis of the MAS rotor by means of a pneumatic drive. A suction device (100) is provided in a space below the radial bearing for suctioning-off the gas introduced by the gas supply device, and generates an underpressure in the space below the radial bearing during measurement operation. This provides a stator for NMR-MAS spectroscopy in which the closure at the head end of the stator is omitted.

Abstract: A superconducting magnet coil system with high resistance to quench events includes a first coil portion (1) with a first superconducting material and a second coil portion (2) with a second superconducting material. The first superconducting material has a higher critical temperature than the second superconducting material. The first and the second coil portions are bridged by a common quench protection element (6) and together with the quench protection element form a first loop. The magnet coil system also includes a third coil portion (3) which is part of a second electrical loop with a second quench protection element (8, 8?, 8?)as well as a heating element (9) which is supplied with a heating voltage in response to a quench of the third coil portion. Among the series connected coil portions (1, 2) only the second coil portion is in thermal contact with the first heating element (9).

Abstract: An NMR DNP-MAS probe head (10) has an MAS stator (2) for receiving an MAS rotor (3) having a sample substance in a sample volume (4), and a hollow microwave waveguide (5)? for feeding microwave radiation through an opening (5a) of the microwave waveguide into the sample volume, an axially expanded rod-shaped microwave coupler (6) located in the opening made of dielectric material, characterized in that the microwave waveguide has a conically tapered hollow transition piece for coupling in an HE 11 mode, into which the microwave coupler projects at an all-round radial distance to the opening of the microwave waveguide. It is thus possible, in a surprisingly simple manner and by means of readily available technical means, to irradiate a considerably higher microwave energy in the HE 11 mode into the NMR measuring sample than by means of the known arrangements.

Abstract: A cryostat arrangement (1), with a vacuum container (2) and an object (4) to be cooled, is provided, wherein the object (4) to be cooled is arranged inside the vacuum container (2) comprising a neck tube (8) leading to the object (4) to be cooled. A closed cavity (9) is formed around the cooling arm (10) of a cold head (11), wherein the cavity (9) in normal operation is filled at least partly with a first cryogenic fluid (34), and wherein a first thermal coupling component (15) is provided for the thermal coupling of the first cryogenic fluid (34) in the cavity (9) to the object (4) to be cooled. The cryostat arrangement (1) further comprises a pump device (14), to which the cavity (9) is connected, and with which the cavity (9) is configured to be evacuated upon failure of the cooling function of the cold head (11). Various cryostat configurations are provided.

Abstract: A sample polarization system comprises an input stage that includes a sample input port configured and arranged to receive and to provide a sample molecule carrier, and cool the sample molecule carrier from a first temperature to a second temperature as it travels along a length of the input stage, and provides the sample molecule carrier at a input stage output. A closed volume having an interior receives the sample molecule carrier from the input stage output and holds a plurality of sample molecule carriers in the high magnetic field created by a magnet adjacent to the closed volume, and outputs the sample molecule carrier from a closed volume output port.

Abstract: An arrangement for setting the spatial profile of a magnetic field in a working volume of a main field magnet (2), in particular a superconducting main field magnet, of a magnetic resonance installation. The main field magnet is arranged in a cryostat (1) and the spatial profile is set by a passive shim apparatus (3) with magnetic field forming elements which are arranged within the cryostat during operation and which have cryogenic temperatures. The magnetic resonance installation contains a room temperature tube (4), in which the sample volume is situated during operation. The passive shim apparatus is introduced into or removed from the cold region of the cryostat via a vacuum lock (5), without needing to ventilate the cold region of the cryostat. This provides a relatively simple, cost effective, and time-efficient method to carry out a stable field homogenization using a passive shim apparatus.

Abstract: An NMR spectrometer (131) with an NMR magnet coil (91) having windings of a conductor with a superconducting structure (1), which have a plurality of band-segments (2, 2a, 7a-7e, 8a-8d, 15) made of band-shaped superconductor. Each band-segment (2, 2a, 7a-7e, 8a-8d, 15) has a flexible substrate (3) and a superconducting layer (4) deposited thereon, wherein the band-segments (2, 2a, 7a-7e, 8a-8d, 15) each have a length of 20 m or more. At least one of the band-segments (2, 2a, 7a-7e, 8a-8d, 15) forms a linked band-segment (2, 2a), and each linked band-segment (2, 2a) is connected to at least two further band-segments (7a-7e) in such a way that the combined further band-segments (7a-7e) overlap with at least 95% of the total length (L) of the linked band-segment (2, 2a). The magnet coil generates particularly high magnetic fields in a sample volume and has a low drift.

Abstract: A device for supplying cold gases to an NMR installation or analytical apparatus equipped with a measuring probe, with cold gases ensuring the cooling of the sample contained in the probe, but also its lift and rotation, the device including an insulated tank containing liquid gas at boiling point and in which are arranged exchangers through which gas streams to be cooled pass, these exchangers being connected to transfer lines channeling the cooled gases to the probe. The device also includes at least one additional exchanger that ensures a pre-cooling of the gas stream before it is channeled to the corresponding exchanger, with the or each additional exchanger coming in the form of a double-flow exchanger that is supplied either by the gaseous vapor produced by the boiling of the liquid gas in the tank or by the cold gas that is evacuated or that escapes at the probe.

Abstract: An NMR (nuclear magnetic resonance) probe head has a microwave resonator with at least two elements which are reflective in the microwave range, at least one of which is focusing. The reflective elements at least partly delimit a resonance volume of the microwave resonator. At least one of the reflective elements is a DBR (“Distributed Bragg Reflector”), and the NMR probe head has at least one NMR coil integrated into the DBR. The NMR detection coil can thereby be positioned particularly near to the sample and the distortions of the static field by resonator components are reduced, such that the detection sensitivity and the spectral resolution of the experiment are significantly improved.

Abstract: An MPI method determines calibration and measurement volumes, wherein the calibration volume is larger than the measurement volume and the overall measurement volume is arranged within the calibration volume. Calibration signals are detected and a system matrix S is created. An MPI measuring signal u is recorded, a location-dependent magnetic particle concentration c with magnetic particle concentration values ci within the calibration volume is reconstructed and the magnetic particle concentration values ci are associated with voxels in the calibration volume. Magnetic particle concentration values ci which were associated with voxels outside of the measurement volume are discarded and an MPI image is generated which exclusively contains magnetic particle concentration values ci which were associated with the voxels within the measurement volume. MPI image data are thereby generated with little artifacts within a short time even in case of high magnetic particle densities outside of the measurement volume.

Abstract: A connecting device in a pulse tube cooler system branches such that a first line branch (11) has a first flexible line segment (4a) and a second line branch (12) has a second flexible line segment (4b), the flexible line segments being arranged in parallel with and offset from one another. The flexible line segments each have a front segment end (17, 18) and a rear segment end (19, 20), the front segment end (17) of the first flexible line segment (4a) and the rear segment end (20) of the second flexible line segment (4b) are rigidly connected to one another, the rear segment end (19) of the first flexible line segment (4a) and the front segment end (18) of the second flexible line segment (4b) are rigidly connected to one another, and there is no continuous rigid connection between the control valve and the cold head.

Abstract: A cooling device (20) has a cryostat (23) and a cold head (1), in particular, the cold head (1) of a pulse tube cooler. The cryostat (23) has a vacuum container (4) with a vacuum container wall (4a), wherein the vacuum container wall (4a) seals off a vacuum inside the vacuum container (4) from the environment. A flexible sealing section (6) connects the vacuum container wall (4a) directly or indirectly to the room temperature part (1a) of the cold head (1). The flexible sealing section (6) seals off the inside of the cryocontainer (2) from the environment. The cooling device further reduces mechanical coupling between the cold head and the cryostat, in particular, in order to enable performance of NMR measurements with fewer disturbances due to external vibrations.

Abstract: An NMR spectrometer (1?) has a sample changer (4?) with at least one cylindrical sample holder (7?, 7?) for receiving an elongated NMR sample at a loading position (5) and for transferring the NMR sample into the measurement volume at a transfer position (6). The sample holder is open in an upward direction and the cylinder axis of the cylindrical sample holder is inclined at the loading position by an angle of inclination a of between 30 and 60 degrees with respect to the vertical and it extends vertically at the transfer position. A positioning device is provided, which transfers the NMR sample at or after the transfer position into the measuring position in the measurement volume with a vertically aligned sample axis of the NMR sample. The spectrometer enables a more ergonomically favorable feed of the sample.