Bruker Analytische Messtechnik Gmbh

Bruker Biospin Gmbh

Bruker Analytik Gmbh

Bruker Analytical Mebtechnik Gmbh

Dieter Schmalbein

Reinhard Biehl

Andreas Kamlowski

Ekkehard Gentsch

Karoly Holczer

Diether Maier

Gunther R Laukien

Peter Hoefer

Marian Kloza

Ralph T Weber

Arne Kasten

Arthur H Heiss

Gisela Gauthausen

Viktor Ringeisen

Peter Hofer

Jin Jie Jiang

Thomas Schmidt

JinJie Jiang

A method and an apparatus serve the purpose of determining the fat or oil content of a sample. The sample is dried under the action of a microwave field and is examined under the action of a radio-frequency signal and of a constant magnetic field by means of nuclear magnetic resonance. The sample is exposed to the microwave field, the radio-frequency signal and the magnetic field at the same measuring place in a common measuring chamber. The apparatus has a microwave source for drying the sample, a magnetic system for generating a nuclear magnetic resonance magnetic field in the sample, and a nuclear magnetic resonance measuring arrangement for irradiating radio-frequency signals into the sample and for receiving excited nuclear magnetic resonance signals from the sample. The microwave source, the magnetic system and the nuclear magnetic resonance measuring arrangement are connected to a common measuring chamber in which the sample is located.

Method and apparatus for determining the fat or oil content of a sample

An apparatus for determining a quantitative property of a sample substance by means of magnetic resonance is disclosed. The apparatus comprises a conveyor for conveying sample containers containing the sample substance through a measuring station. The measuring station comprises a magnet system for generating a constant magnetic field of high homogeneity. The measuring station, further, comprises a probe head adapted for letting sample containers be conveyed therethrough and for generating a high frequency magnetic field. A magnetic resonance measuring unit determines the quantitative property of the sample substance contained in the probe head. The probe head excites and detects, resp., the magnetic resonance essentially only within that section of the sample container which contains the sample substance. The probe head comprises a split-ring resonator which, as seen in a conveying direction of the conveyor, has a passage cross-section for letting run the sample containers therethrough. The high frequency magnetic field is generated essentially only in an area of the passage cross-section through which the sample containers run during conveying.

Apparatus and probe head for determining a quantitative property of a sample substance by means of magnetic resonance

A method is described for determination of the content of at least one component of a sample by means of a nuclear magnetic resonance pulse spectrometer, with the magnetization of the sample being influenced by a sequence of radio-frequency pulses such that the signal amplitudes to be observed can be determined. The magnetization of the sample is initially saturated, and the signal amplitudes which are determined at each time by the longitudinal and transverse relaxation times Tand Tand/or T* and/or T, from which a value for the content of the at least one component is determined, are measured at the same time in a cohesive experimental procedure.

Method for determining the content of at least one component of a sample by means of a nuclear magnetic resonance pulse spectrometer

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.

Resonator apparatus for electron spin resonance (ESR) measurements and method for measuring electron spin resonance (ESR) signals

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. The sample substance comprises a chromium-doped magnesium oxide (Cr:MgO). The magnesium oxide is doped with the isotope Cr.

Probehead and a sample substance for an electron spin resonance dosimeter

A method and an apparatus for investigating the imperishability of n liquid foodstuffs using electron spin resonance (ESR) exposes samples of the foodstuffs to an elevated temperature for an extended time-period. At predetermined intervals during the period, the intensity of an ESR signal of each sample is measured and plotted vs. time in a diagram for that sample. The time of a superproportional increase in intensity is detected for each foodstuff. The number n of different foodstuffs is determined by dividing the predetermined interval by the measurement time. The n samples are investigated simultaneously by sequentially cycling the n samples through a common sample vessel. Each time, the intensity of the ESR signal of the sample is measured and then plotted in a diagram unique to that foodstuff. The sequence of foodstuffs are cycled through the sample vessel until a predetermined number m of measuring points per foodstuff has been attained.

Method and apparatus for investigating the imperishability of liquid foodstuffs by means of electron spin resonance

A method and an apparatus are disclosed for detecting an atomic structure of a sample along a surface thereof. The method comprises arranging the sample in a constant magnetic field (B.sub.0) of predetermined field strength and high homogeneity and irradiating a high-frequency magnetic field (B.sub.1) of a predetermined frequency on the sample, wherein the fields (B.sub.0) and (B.sub.1) are oriented perpendicularly to each other. The method further comprises providing a force-sensitive sensor having a paramagnetic tip comprising a paramagnetic material. The sensor is placed in close vicinity to the sample such that the paramagnetic tip is in atomic interaction with the sample surface which means that the distance between the tip and the surface is in the order of between 1 and 10 .ANG.. The predetermined field strength and the predetermined frequency are set such that electron paramagnetic resonance (EPR) is excited within the tip paramagnetic material. The paramagnetic tip is then displaced parallel to the sample surface for mapping predetermined points on the sample surface. During displacing the tip the force exerted on the tip by a local inhomogeneous magnetic field (B.sub.loc) caused by atomic magnetic moments (m.sub.e,k) of the sample is measured.

Magnetic resonance method and apparatus for detecting an atomic

A pulsed electron spin resonance spectrometer is provided with a first microwave oscillator for generating measuring signals of a high microwave frequency of about 80 GHz or above. A second microwave oscillator generates auxiliary signals at a lower microwave frequency of about 12 GHz or below. A first mixer generates mixed signals by mixing a measuring signal with an auxiliary signal. A pulse shaping channel generates pulsed mixed signals having a pulse length sufficient for carrying out pulsed electron spin resonance experiments. Moreover, a measuring resonator is provided to which the pulsed mixed signals are applied. A second mixer generates an output signals of a lower microwave frequency by mixing the mixed signal outputted from the measuring resonator with a signal being derived from the first microwave oscillator. A pulse shaping channel is switched between the second microwave oscillator and the first mixer.

Method of measuring pulsed electron spin resonance signals and pulsed

A method and a device for tuning a HF source, which oscillates at a basic frequency, to a narrow-band component, in particular for tuning a microwave source 61 of an electron spin resonance spectrometer to a resonator 62. In order to mutually tune the resonance frequency F.sub.R of the resonator 62 and the basic frequency f.sub.O of the source 61, the output signal of the source 61 is mixed in a mixer 64 with a sweep signal of an oscillator 65. The behavior of the resonator 62 is observed on a visual display unit 67, via a detector 68, in the form of what is called a 'mode curve', and the source 61 is re-tuned so that two dips in the mode curve are brought into coincidence.

Method and device for tuning a HF source, in particular for tuning a

A resonator arrangement 10 serves for electron spin resonance spectroscopy. It comprises an upper carrier plate 30, a long center portion 32, 33, 40, 41 and a lower resonator section 45, 46, 47. In the area of the center portion 32, 33, 40, 41, there is provided at least one separating plane 50, 51 along which the resonator arrangement 10 can be divided into an upper part 52 and a lower part 52, it being possible to connect a plurality of different lower parts 53 to one and the same upper part 52.

Resonator arrangement for electron spin resonance spectroscopy

A resonator arrangement is provided for electron spin resonance spectroscopy. It comprises an annular, dielectric resonance ring 11 where field lines 13 of the resonance field emerge in the direction of the axis 12 of the resonance ring 11 and close in the outer space 18. There is further provided a coupling means for coupling and decoupling microwave energy into and out of the resonance ring 11. The coupling means comprises a coupling loop 14 which is arranged in the outer space 18 and adapted for being displaced in a direction 16 parallel to the axis 12.

A resonator is provided for electron spin resonance spectroscopy. The resonator comprises a first wall element which delimits a cavity and which is in releasable contact with other wall element delimiting the cavity. The connection between the first wall element and at least one of the additional wall elements is effected only by spring force (single figure).

Resonator for electron spin resonance spectroscopy

A resonator is provided for electron spin resonance spectroscopy. It comprises a resonant element comprising a cavity, and a predetermined oscillation mode is capable of propagating in the cavity. The resonator comprises further a coupling element comprising a waveguide section. Finally, the resonator is equipped with a tuning arrangement for coupling an electromagnetic wave in the waveguide section with the oscillation mode in the cavity. The tuning arrangement comprises at least one conductive wafer, which is arranged at the free end of a tuning rod projecting into the waveguide section and is adapted for displacement in the direction of a longitudinal axis of the tuning rod. The wafer further coacts with a coupling element disposed between the waveguide section and the cavity. Two wafers are arranged on either side of the coupling element, in the direction of the longitudinal axis, and can be displaced in opposite senses relative to the coupling element.

A resonator is provided for electron spin resonance spectroscopy. The resonator comprises walls defining a cavity. In the cavity, a predetermined oscillation mode of a preselectable frequency, in particular in the Q band, is capable of propagating. The walls are provided with an opening for irradiating a radiation, in particular light rays. The cavity has a cylindrical shape. An oscillation mode of the type TE.sub.01n is excited, with n being greater than one. The opening is configured as an annular slot extending substantially all around the cylindrical jacket, which defines the cavity, in a radial plane at a distance of m L/4 from a radial end wall delimiting the cavity, and m is an odd number and greater than one (FIG. 2).

A cavity resonator serves to generate magnetic dipole transitions in a sample, for instance for carrying out electron spin resonance measurements. The natural frequency of the cavity resonator (10) is influenced by a reduction in length of the E flux lines. To this end, conductive areas (20) are arranged at the points where the E flux lines are encountered. This results in an increase of the space factor, related to an unchanged specimen volume, and thus in an improvement of the measuring sensitivity.

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Marxzell-Burbach, Germany

Dieter Schmalbein