Abstract: A cryostat configuration for keeping liquid helium, comprising an outer jacket (2) accommodating a helium container (5), a neck pipe (3) which is filled with gaseous helium during operation, and a refrigerator (1; 1b), wherein the outer jacket (2), the helium container (5) and the neck pipe (3) delimit an evacuated chamber (9) which surrounds the helium container (5); and wherein the refrigerator (1; 1b) has a cooling finger (4) which has a condensation body (15; 15b) in the region of the lower end of the neck pipe (3), is characterized in that the condensation body (15; 15b) is partially surrounded by a condensation chamber (16; 16b) which has a first lower opening (17) to permit draining of liquid helium, and a second opening which communicates with a lower end of a gas supply pipe (18), wherein the upper end of the gas supply pipe (18) terminates in the region of the upper end of the neck pipe (3). This improves the thermal properties of the cryostat configuration.

Abstract: A probehead for an electron spin resonance (ESR) dosimeter comprises a resonator and an insert extending into the resonator. The insert has a guide channel for bringing a sample into the resonator. The sample comprises a dosimeter substance. The guide channel is configured for receiving and guiding a test strip. The insert is provided with a first machine-readable code imprint. The insert is provided with at least one reference sample. A pressurized air unit is provided for blowing the sample out of the resonator after completion of a measurement. The insert has an opening on an upper side of the resonator. The opening is openly accessible for manually inserting dosimeter pills thereinto. The insert, further, is provided on the upper side with a pressurized air connector. The pressurized air connector is connected to an orifice via a pressurized air channel within the insert. The orifice is located within a lower, otherwise closed bottom of the guide channel.

Abstract: A description is given of a method for determining the content of a first component of a sample, which first component provides a first NMR signal and has a first self-diffusion coefficient D1, the sample additionally containing at least one further component which provides a further NMR signal and has a larger self-diffusion coefficient D2, in particular for determining the fat content of a hydrous sample, with the aid of a low-resolution nuclear magnetic resonance (NMR) pulse spectrometer, the sample being excited by a radio-frequency (RF) excitation pulse and being exposed to a magnetic gradient field and to a sequence of further refocusing RF pulses for generating spin echo signals, the spin echo signals being detected and their amplitude values being determined, from which a value for the content of the first component of the sample is determined. The magnetic gradient field is not switched off during the sequence of further refocusing RF pulses.

Abstract: An NMR magnet coil system, comprising superconducting conductor structures, with an inductance L0 for generating a homogeneous magnetic field B0 through which an operating current I0 flows in the persistent mode, and wherein further superconducting switches (S1, S2, . . . Sn−1) are each provided between two points (P1, Q1), (P2, Q2), . . . , (Pn−1, Qn−1) of the winding of the magnet coil system which, during operation, separately superconductingly short-circuit one or more disjoint partial regions (1, 2, . . . , n−1) with the inductances L1, L2, . . . , Ln−1 to generate magnetic field contributions B1, B2, . . .

Abstract: The invention concerns an NMR (nuclear magnetic resonance) high field magnet coil system comprising superconducting conductor structures for generating a homogeneous magnetic field B0 in a measuring volume (23) with several radially nested solenoidal coil sections (12, 13, 31), which is characterized in that the radially innermost coil section (31) is wound with a band-shaped superconductor with an aspect ratio (width to thickness) >3 on a coil support which axially projects, at least at one axial end, past the winding packet of the radially neighboring coil section (12) and the band-shaped superconductor is guided on this side tangentially towards the outside to a region of reduced magnetic field strength and terminates in at least one electrical connecting point (16). This permits use of a brittle band-shaped superconductor for the innermost coil system (31) which cannot be strongly bent at the upper edge.

Abstract: The invention concerns an NMR (nuclear magnetic resonance) high field magnet coil system comprising superconducting conductor structures for generating a homogeneous magnetic field B0 in a measuring volume (23) with several radially nested solenoidal coil sections (12, 13, 31), which is characterized in that the radially innermost coil section (31) is wound with a band-shaped superconductor with an aspect ratio (width to thickness) >3 on a coil support which axially projects, at least at one axial end, past the winding packet of the radially neighboring coil section (12) and the band-shaped superconductor is guided on this side tangentially towards the outside to a region of reduced magnetic field strength and terminates in at least one electrical connecting point (16). This permits use of a brittle band-shaped superconductor for the innermost coil system (31) which cannot be strongly bent at the upper edge.

Abstract: A superconducting high-field magnet coil (1; 27; 38) comprising at least one radially inner (2) and at least one radially outer coil section (3; 32; 33), wherein at least the radially inner coil section (2) is wound in a solenoid-shaped fashion with an HTS (high temperature superconductor) band conductor (14; 20; 36) and wherein at least one superconducting connection is provided between the radially inner coil section and the radially outer coil section is characterized in that the superconducting connection comprises a first superconducting joint (5; 39) between two HTS band conductors at which the HTS band conductor of the radially inner coil section is connected to at least one further HTS band conductor (6; 21, 22; 29; 40), flatly overlapping same, such that the two HTS band conductors mutually subtend an angle of between 30° and 150°, and with a second superconducting joint (7; 41) which is electrically connected in series with the first, and which is geometrically disposed in a region of consid

Abstract: A multiport switching valve for a liquid flow system is described, comprising a first member having a plurality of ports for connecting liquid lines thereto, a second member, connected with a first member and movable relative to the first member, the second member comprising a plurality of channels, wherein the channels are arranged such that, according to a selected relative position between the first and second member, one or more of said channel connect predetermined ones of the ports of the first member with one another in a liquid conducting manner. The first member comprises at least one group of ports arranged in one substantially straight line or at least two adjacent substantially parallel and substantially straight lines, and the second member comprises a plurality of segments, wherein the segments have one or more channels arranged therein, the channel or channels of each segment representing a predetermined connection scheme for connecting predetermined ones of the ports with one another.

Abstract: A superconducting high-field magnet coil (1; 27; 38) comprising at least one radially inner (2) and at least one radially outer coil section (3; 32; 33), wherein at least the radially inner coil section (2) is wound in a solenoid-shaped fashion with an HTS (high temperature superconductor) band conductor (14; 20; 36) and wherein at least one superconducting connection is provided between the radially inner coil section and the radially outer coil section is characterized in that the superconducting connection comprises a first superconducting joint (5; 39) between two HTS band conductors at which the HTS band conductor of the radially inner coil section is connected to at least one further HTS band conductor (6; 21, 22; 29; 40), flatly overlapping same, such that the two HTS band conductors mutually subtend an angle of between 30° and 150°, and with a second superconducting joint (7; 41) which is electrically connected in series with the first, and which is geometrically disposed in a region of consid

Abstract: The invention concerns an NMR sample holder for NMR samples with a short sample tube of constant diameter which is clamped in a largely gas-tight fashion and with a movable plunger and a rotor. The inventive device increases flexibility compared to conventional sample holders, reduces the vapor volume over the sample liquid in the sample tube and prevents deviations from precise orientation. The invention also concerns a method for simple and safe exchange of the sample tube thereby drastically minimizing loss through breakage.

Abstract: The invention concerns a means and a method for stabilizing a magnetic field generated by a superconductingly short-circuited main coil located in a cryostat in the measuring volume of a high-resolution magnetic resonance spectrometer, which comprises compensation coils which are dimensioned and positioned such that they, in their entirety, are suited to largely compensate for field drifts of the superconductingly short-circuited main coil in the measuring volume. The drift compensation coils consist of HTS material and are disposed radially outside of the main coil at a higher temperature level.

Abstract: In a magnetic resonance (MR) apparatus comprising a main field magnet system with a tubular opening for receiving the object to be investigated and at least one tubular mechanically oscillatory component, disposed in this opening, in particular a gradient coil system, and at least one cylindrical element of electrically conducting material surrounded by the main field magnet system, which is rigidly mechanically connected to at least one of the mechanically oscillatory components or forms an integral mechanical component thereof, the sum of the products p of the electric conductivities &sgr;, the cylinder radii R and the wall thicknesses d of the cylindrical element per mechanically oscillatory component is between 1 Am/V and 10,000 Am/V, preferably between 10 Am/V and 1000 Am/V, and particularly preferred between 20 Am/V and 500 Am/V. This produces good noise damping in an inward direction.

Abstract: A cryostat configuration for keeping liquid helium, comprising an outer jacket (2) accommodating a helium container (5), a neck pipe (3) which is filled with gaseous helium during operation, and a refrigerator (1; 1b), wherein the outer jacket (2), the helium container (5) and the neck pipe (3) delimit an evacuated chamber (9) which surrounds the helium container (5); and wherein the refrigerator (1; 1b) has a cooling finger (4) which has a condensation body (15; 15b) in the region of the lower end of the neck pipe (3), is characterized in that the condensation body (15; 15b) is partially surrounded by a condensation chamber (16; 16b) which has a first lower opening (17) to permit draining of liquid helium, and a second opening which communicates with a lower end of a gas supply pipe (18), wherein the upper end of the gas supply pipe (18) terminates in the region of the upper end of the neck pipe (3). This improves the thermal properties of the cryostat configuration.

Abstract: A resonator apparatus and a method for electron spin resonance (ESR) measurements are disclosed. The resonator apparatus comprises a dielectric resonator and a sample vessel extending through the resonator. The sample vessel is configured as one single flexible tube. Means are provided for conveying a liquid sample substance through the flexible tube. According to the method a liquid sample substance is guided through the sample vessel, wherein the sample substance is gated by cyclically conveying and stopping, resp., a flow of the sample substance. A measurement is conducted within the resonator when the flow of sample substance is stopped.

Abstract: A probehead for an electron spin resonance (ESR) dosimeter comprises a resonator and an insert extending into the resonator. The insert has a guide channel for bringing a sample into the resonator. The sample comprises a dosimeter substance. The guide channel is configured for receiving and guiding a test strip. The insert is provided with a first machine-readable code imprint. The insert is provided with at least one reference sample. A pressurized air unit is provided for blowing the sample out of the resonator after completion of a measurement. The insert has an opening on an upper side of the resonator. The opening is openly accessible for manually inserting dosimeter pills thereinto. The insert, further, is provided on the upper side with a pressurized air connector. The pressurized air connector is connected to an orifice via a pressurized air channel within the insert. The orifice is located within a lower, otherwise closed bottom of the guide channel.

Abstract: A superconducting very high field magnet coil with several solenoidal multi-layer coil sections which are wound in layers onto a hollow cylindrical support body (3) about a common central axis a, and which are electrically connected in series to carry a current in excess of 100 A is characterized in that the radially innermost coil section (1) comprises superconducting wire (2) which contains oxidic, high temperature superconductor (HTS) material, wherein the layers of the radially innermost coil section (1) are helically wound such that there is a free axial space between the walls, which is then sealed.

Abstract: An NMR magnet coil system, comprising superconducting conductor structures, with an inductance L0 for generating a homogeneous magnetic field B0 through which an operating current I0 flows in the persistent mode, and wherein further superconducting switches (S1, S2, . . . Sn−1) are each provided between two points (P1, Q1), (P2, Q2), . . . , (Pn−1, Qn−1) of the winding of the magnet coil system which, during operation, separately superconductingly short-circuit one or more disjoint partial regions (1, 2, . . . , n−1) with the inductances L1, L2, . . . , Ln−1 to generate magnetic field contributions B1, B2, . . . , Bn−1 to the homogeneous magnetic field B0, is characterized in that the following is valid: 1 α = &LeftBracketingBar; L 0 ⁢ ∑ j = 1 n ⁢ ( L - 1 ) jn ⁢ B j B 0 &RightBracketingBar; ≤ 0.

Abstract: A main field magnet arrangement for a one-sided magnet resonance device produces a homogeneous magnetic field B in a working volume (4). The working volume (4) and the main field magnet (1) are disposed on different sides of a plane E and the main field magnet (1) has a geometric shape which permits disposal of a radio frequency (RF) receiver coil system and optionally a gradient coil system on the same side of the plane E as the main field magnet (1). Field-generating elements of permanent-magnetic material form a radially outer part (2) and a radially inner part (3) relative to an axis A extending through the center of the working volume (4), wherein the surface, facing the working volume (4), of the radially inner part (3) is axially further spaced apart from the center of the working volume (4) than the surface of the radially outer part (2) facing the working volume (4), such that a depression (5) is formed in the radially inner part (3) in the axial direction.

Abstract: A magnet coil arrangement comprising an actively shielded superconducting primary circuit (21) comprising first and second magnet windings (1,2,3 and 4,5), and being wound e.g. in winding chambers (7,8,9 and 10,11) in a supporting body (6a,6b) for generating a strong magnetic field in a working volume with a small magnetic stray field and a short circuited secondary circuit (22) which is inductively coupled with the primary circuit (21) and contains third and fourth magnet windings (13,14,15 and 16,17) is characterized in that the magnet windings (13,14,15 and 16,17) of the secondary circuit (22) form an actively shielded magnet coil. This permits a simple and robust coil protection for actively shielded superconducting magnets during a quench wherein the superconducting magnet windings are reliably relieved and the magnetic stray field of the entire arrangement remains small.

Abstract: A main field magnet arrangement for a one-sided magnet resonance device produces a homogeneous magnetic field B in a working volume (4). The working volume (4) and the main field magnet (1) are disposed on different sides of a plane E and the main field magnet (1) has a geometric shape which permits disposal of a radio frequency (RF) receiver coil system and optionally a gradient coil system on the same side of the plane E as the main field magnet (1). Field-generating elements of permanent-magnetic material form a radially outer part (2) and a radially inner part (3) relative to an axis A extending through the center of the working volume (4), wherein the surface, facing the working volume (4), of the radially inner part (3) is axially further spaced apart from the center of the working volume (4) than the surface of the radially outer part (2) facing the working volume (4), such that a depression (5) is formed in the radially inner part (3) in the axial direction.