Bruker Biospin Ag

Bruker Switzerland Ag

Dirk Wilhelm

Thomas Speck

Oskar Schett

Joerg Hinderer

Markus Mayer

Daniel Schmidig

Beat Grossniklaus

Schimun Denoth

Silvia Buttazzoni

Joost A B Lohman

Hannes Grubinger

Danijela Al Adwan Stojilkovic

Philipp Gisler

Christoph Pfenninger

Federico Raffa

A DNP apparatus includes a cryostat () having an opening () and a loading path for a sample (), the loading path extending from the opening to a sample receptacle (), with a cryomagnet and a microwave source () as well as a configuration for supplying microwave radiation from the microwave source to the sample, which comprises a microwave path extending directly to the sample. The microwave path extends spatially separately from the loading path and the configuration for supplying microwave radiation has at least one microwave feed-through passing through one or more walls of the cryostat. The microwave path is incident on the sample from a direction opposite to the loading path or from a sideward direction at right angles to or at an inclination with respect to the axis of the loading path. This leads to simple and efficient polarization of the electron spins in the sample.

DNP apparatus

An NMR probe head () has a coil system () and a radial centering mechanism for a sample vial () having two centering devices spaced axially from each other to center the sample vial in the radial direction only. The first centering device () is disposed above the receiver coil system and at least one further centering device () is disposed axially above the coil system with an axial spacing (d) above the first centering device. The first and second centering devices restrict the radial scope for movement of the sample vial to such an extent that the sample vial cannot touch an endangered space () during the entire duration of transport of the sample vial to its measuring position, thereby precluding damage to the probe head components in the endangered space by the sample vial.

NMR probe head with improved centering of the sample vial

In a coil arrangement for nuclear magnetic resonance comprising a main coil (), a shielding coil (), and at least one correction coil (), the function of which consists in forming a magnetic field gradient with eddy current properties which are as good as possible, the main coil () and the shielding coil () are electrically connected in series with the correction coil (). The deviations of the residual field from the desired design generated by production tolerances are thereby modified by the correction coil in such a fashion that the long-lasting eddy currents are suppressed. This either reduces the waiting time that must lapse after a gradient pulse before a predetermined field homogeneity is achieved or e.g. the deviations from the desired field are minimized in imaging applications.

Gradient coil with correction windings and method for production thereof

An NMR measuring configuration has a temperature control device for a sample vial (). The temperature control device has a temperature sensor with supply wires which are both surrounded by a sensor tube (). The sensor tube () is connected to a measurement space via a sensor flow inlet () in such a way that a partial flow of a temperature-control fluid flows as a temperature-control flow () into a free space () between the temperature sensor and the inner wall of the sensor tube along the supply wires and flows out of the sensor tube via a sensor flow outlet () at the opposite end of the sensor tube. This minimizes both the temperature penetration factor and the difference between the sensor and sample temperatures (&#x394;Tp).

NMR measuring configuration with temperature control device for a sample vial

A sample container () for NMR measurements defines a volume (V) of sample substance. The sample container () has a first interface (G) towards an environment () and a second interface (G) towards the sample substance (). A susceptibility jump at the second interface Gis sufficiently large that the maximum value of |B'/B| within the volume (V) is at least 0.5 ppm. The geometry of the sample container () is selected in such a fashion that, when a homogeneous magnetic field Bhas been applied, a location-dependent relative field change F is present in the volume (V), which is larger than 20 ppb at least at one point in a center partial volume (V) and a first residual field (R) in the center partial volume (V) is smaller than 1.6 ppb. A second residual field (R) in the lower partial volume (V) is smaller than 30 ppb.

NMR measuring configuration with optimized sample container geometry and method for calculating the shape of the sample container

Temperature control device () for an NMR sample tube (), wherein multiple interleaved, concentric flow channels () for temperature control fluid extending coaxially with respect to a cylindrical interior space () for holding the NMR sample tube are constituted around said interior space (), wherein said temperature control device is constituted such that it is closed toward the interior space in an axial end region () and, an axial end region () at the opposite end thereto, open to the interior space for inserting the NMR sample tube into said interior space (), wherein, in a counter flow region (GB), adjacent flow channels () are interconnected through a fluid passage () at one axial end in such a way that the direction of a fluid flow in the flow channels of the counter flow region is reversed with respect to the corresponding adjacent flow channel in the counter flow region, wherein the outermost flow channel () of the counter flow region has a fluid inlet () at one axial end, and wherein the innermost flow channel () of the counter flow region has a fluid passage () to the interior space at one axial end that faces toward the axial end region that is closed, is characterized in that at least one of the flow channels, in particular, the outermost flow channel () of the temperature control device and/or the next outermost flow channel () of the temperature control device has a fluid outlet () at one axial end, through which at least part (MS) of the temperature-controlling fluid flow that is conveyed along the outermost flow channel () of the temperature control device can escape from the temperature control device without passing through all of the flow channels of the counter-low region. With this invention, temperature control of an NMR sample tube can be ensured with low temperature gradients, while achieving a high temperature control performance.

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Maur, Switzerland

Dirk Wilhelm