Abstract: In an analytic spectrometer (50) having a central computer (9), permanently installed and exchangeable components (5), such as a radiation source, a detector, a beam splitter, a filter, external measurement probes and the like, each of which exhibiting a readable data carrier (7) with encoded data of parameters characterizing the respective component (5), the data media (7) can be written to and contains changeable time dependent data concerning the history and/or the actual properties of the corresponding component (5) for example length of operation, performance deterioration parameters or calibration curves of the component (5). These data can be continuously adjusted by the central computer (9) to the current state of the component (5) so that the data medium (7) connected to the component (5) can immediately supply information concerning the current actual properties of the component (5) when installing the component (5) in another spectrometer.

Abstract: The invention concerns an optical or infrared Fourier spectrometer with a plurality of entrances and exits for the coupling on of external sources or samples. The entrances can also be used as exits and vice versa.

Abstract: The invention concerns a method for adjusting the desired current values of shim coils of a tesseral harmonic (off axis) shim system in order, in particular in the center of the shim system, to produce as homogeneous a magnetic field as possible. Utilizing a minimal number of measuring points and appropriate linear combinations of the corresponding measurement values with and without switching on the corresponding shim coil, a simple, systematic and reliable measurement method is introduced which does not require any iterative procedure. The method can be used by itself or the desired current values can serve as starting values for a further shimming procedure.

Abstract: A nuclear magnetic resonance spectrometer, in particular a nuclear spin tomograph serving to investigate biological samples, comprising a magnetic coil for generating a substantially homogeneous magnetic field in a volume under examination, and a set of shim coils for eliminating any remaining inhomogeneities of the magnetic field is characterized in that at least one additional electric conductor, preferably an additional shim coil, is provided which may be arranged in the volume under examination, in the direct vicinity of the sample, that the additional conductor is designed in such a way that it will generate an inhomogeneous magnetic field when loaded with current, and that it can be loaded with currents of a type generating inhomogeneous magnetic fields which will eliminate, at least partially, and in a selected area in the sample, local field inhomogeneities resulting from susceptibility variations within the sample, for example. This enables the accuracy of the spectroscopy results to be improved.

Abstract: A sample holder for placing a sample substance for transmission measurements with optical radiation into a spectrometer, in particular, a FTIR spectrometer which is at least partially made from a material transparent to the optical radiation in a intermeshing wavelength region and which exhibits an index of refraction in excess of 1 is configured as a converging lens with a concave surface (11) and a convex surface (12). To take an absorption spectrum of a powder and/or fluid dissolved or suspended sample substance, the sample substance is brought onto the concave surface (11) of the sample holder before the measurement where it, in consequence of the curvature and in contrast to a flat surface, is concentrated in a substantially smaller surface region. The configuration of the sample holder as a converging lens increases the yield of the radiation penetrating through the sample substance onto the detector of the spectrometer configuration.

Abstract: 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.

Abstract: 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 microwave energy in the form of a continuous-wave signal (CW) or in the form of an intermittent signal (P). Measuring signals emitted by the resonator can be supplied to a detector arrangement and a signal evaluation arrangement. In order to be able to carry out individual experiments with continuous-wave signals or intermittent signals of low power or with intermittent signals of high power in arbitrary combination and with an arbitrary succession of microwave pulses, the spectrometer comprises a first channel for supplying a continuous-wave signal or an intermittent signal of small power in the mW range and a second channel for supplying an intermittent signal of high power in the W range. The channels are connected by their inputs to a common microwave source and united at their outputs.

Abstract: 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).

Abstract: A magnet coil (30) comprises at least one first winding made of wire (34) which is superconductive at operating temperature and at least one second winding made of normally conductive wire (36). In addition, means are provided for supplying a current into the second winding, which is completely dead during superconductive operation of the magnet coil (30), when at least certain sections of the superconductive wire (34) assume the normally conductive state.In order to accelerate the spatial propagation of this transition in the magnet coil (30) and at the same time to provide the possibility to use low-cost wires having a relatively small proportion, related to the cross-sectional area, of normally conductive material, the first and the second winding are connected in parallel electrically.

Abstract: A cooling apparatus for a low temperature magnet system includes a superconducting magnet coil (32) which encircles a test space (36). The magnet coil (32) is surrounded by at least one intermediate shield (26, 29) and is contained in an evacuated outer shell (22). On the outer shell (22) is a motor driven refrigerator (11) which actively cools the at least one intermediate shield (26, 29) by means of a cooling arm (18) extending through the outer shell (22). For compensating the disturbing fields emitted by the motorized drive of the refrigerator (11) a sensing device is provided for picking up these magnetic and/or mechanical disturbing signals. The sensor signal controls at least one coil (62) for compensating the disturbing field effective in the test space (36).

Abstract: 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..

Abstract: A test head for electron spin resonance and paramagnetic electron resonance measurements comprises a resonator of circular cylindrical shape adapted to accommodate a coaxially arranged test tube, and a waveguide arrangement for exciting the H.sub.011 wave in the resonator, said waveguide arrangement comprising one section having its one end arranged adjacent one face of the resonator and communicating with the resonator via an opening provided in the face in eccentrical arrangement relative to the resonator. In order to enable the coupling coefficient to be varied and, thus, the resonator to be adapted to the waveguide section, the waveguide section carrying a H.sub.1n wave communicates with the resonator via a coupling slot the angular position (.phi.) of which can be varied relative to the radial plane of the resonator passing through its center. Preferably, the waveguide section exhibits a circular cross-section and can be rotated about its axis. It guides the H.sub.