摘要:
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.
摘要:
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).
摘要:
A specimen head for electron spin resonance and paramagnetic electron resonance measurements, having an annularly cylindrical resonator, with a waveguide being coupled to one of its end walls in such a manner as to excite an H.sub.011 wave. The other end wall is formed by a piston capable of being shifted for tuning, the piston being attached at the end of a hollow piston rod (6) mounted in a bearing block (4), which also contains the resonator (16), in such a manner that it is concentric relative to the axis of the resonator and longitudinally shiftable. The waveguide (13) is attached to the bearing block (4) on that side of the resonator (16) which is opposite the piston (7) and extends along the outside of the bearing block parallel to the piston rod (6) after having been deflected 180.degree.. Drive shafts (24, 34) for means for shifting the piston (7) and means for altering the coupling of the waveguide (13) are arranged on that side of the piston rod (6) opposite the waveguide (13) in the plane containing the axes of the waveguide and the piston rod (6) and are mounted in or on the bearing block (4). The bearing block (4) is attached to a head member (1) by means of rods (3) extending parallel to the waveguide (13) and to the drive shafts (24, 34), with the free end of the waveguide (13) being attached thereto and the free ends of the drive shafts (24, 34) being mounted therein, and having a hole (48) which is concentric relative to the piston rod (6).
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
A test head for ENDOR-triple experiments comprising a cylindrical cavity resonator provided with means for exciting the TM.sub.110 mode and a spiral arranged in concentric relation to the cavity axis and connected to the inner conductor of a coaxial line. The walls of the cavity resonator (5) are provided at two diametrically opposite points with projections (4) projecting into the interior of the cavity resonator, consisting preferably of a poorly conductive material and extending over the full height of the cavity resonator. The projections are formed by tubes (14) recessed into the walls of the cavity resonator and enclosing sections (20, 21) of the turns of a modulation coil (19) intended for modulating a D.C. magnetic field (B.sub.0) existing in the cavity resonator in vertical relation to the plane comprising the projections.
摘要:
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.
摘要:
An electron spin resonance spectrometer comprises a resonator containing a sample and arranged in a magnetic field of constant strength and high homogeneity. A microwave bridge can be supplied with microwave energy in the form of an intermittent signal. Measuring signals emitted by the resonator are supplied to a detector and a signal evaluation stage. A line provided between a microwave source and the microwave bridge is subdivided into parallel pulse-shaping channels, one of them containing a phase shifter, an attenuator and a switch for the signal passing through the pulse-shaping channels. In order to be able to set, if possible, an unlimited plurality of pulse sequences for experiments of all kinds, the pulse-shaping channels are supplied in equal proportions from the line by means of a divider. All pulse-shaping channels are provided with a phase shifter and an attenuator. The pulse-shaping channels are re-united by means of a combiner arranged before the input of a common microwave power amplifier.
摘要:
An electron spin resonance spectrometer comprises a resonator arranged in a magnetic field of constant strength and high homogeneity and containing a sample. The resonator can be supplied, via a microwave bridge, with high-power microwave energy in the form of an intermittent signal. Measuring signals emitted by the resonator can be supplied to detector arrangements and signal evaluation arrangements. In order to be able to cut a pulse-shaped output signal of the microwave power amplifier off sharply at its trailing edge, the attenuator is designed as a switching stage comprising a circulator whose input is connected to the output of the microwave power amplifier. A subsequent circulator connection is wired up to a series connection comprising a microwave switching diode that can be switched via a control input and a waveguide termination, and another subsequent circulator connection is connected to the microwave bridge (FIG. 10).