Abstract: An NMR (nuclear magnetic resonance) detection module (such as an NMR probe) mounted in a vacuum vessel permits a transmit/receive coil to be cooled efficiently and to be placed closer to a sample container. The NMR detection module includes a core module (detection module) (54) consisting of a refrigerant block (118) and a transmit/receive coil formed on the inner surface of a detection hole (130). A sleeve (cylindrical partition wall) (122) forming a part of the vacuum vessel is inserted in the detection hole (130). A sample tube (56) is inserted in the sleeve (122). The refrigerant block (118) is connected to a heat exchanger via a support member (82). Since it is not necessary to form a bobbin inside the transmit/receive coil, the distance between the coil and the sample can be set small. The coil is entirely surrounded by the refrigerant block.

Abstract: A cooled NMR detection probe including a detection coil and an internal structure (65) mounted in a vacuum vessel (58) includes a radiation shield assembly (68), a connecting member (74), and a heat exchanger (80). The internal structure (65) is secured to the vacuum vessel (58) by a holding member (66). If the internal structure shrinks during cooling, the position of an upper portion of the first heat exchanger (80) hardly varies, thus suppressing displacement of a core module (54).

Abstract: An NMR probe has a sample tube insertion port for introducing and withdrawing the sample tube into and from the probe, a sample tube support providing support of the sample tube during NMR measurements, a tubular sample tube passage connecting together the sample tube insertion port and the sample tube support and capable of transporting the sample tube between them, and a gas stream generator for producing a gas stream in the sample tube passage to move the sample tube between the sample tube insertion port and the tube support. The gas stream generator is mounted at an intermediate (non-end) position in the sample tube passage.

Abstract: A high-resolution solid-state NMR spectrometer which can measure a disklike sample. The spectrometer includes: a stator having an air bearing disposed within the static magnetic field, the rotor being disposed in the stator; and an engaging mechanism mounted in a one-end portion of the rotor and detachably holding a sample holder that holds the disklike sample.

Abstract: A spectrometer has: Accumulation means to obtain a data set containing N data points, repeating the measurement M times to obtain M spectral data sets or time-domain data sets S1 (d1 to dN) to SM (d1 to dN), and accumulating the M spectral data sets or time-domain data sets. Means for creating sets S1 (dn) to SM (dn) of the data points contained in the M spectral data sets or time-domain data sets S1 (d1 to dN) to SM (d1 to dN). Correlation computing means for finding correlations. Computing means for finding either the product of an accumulated or anticipated spectrum.

Abstract: A method of controlling the static magnetic field in an NMR spectrometer in such a way that the magnetic field can be homogenized even if there is a temperature gradient across a sample tube. A distribution of resonance frequencies and chemical shift differences within the sample tube is found by NMR measurements for each of two peaks of a calibration sample. A temperature distribution is found based on the distribution of the chemical shift differences. A distribution of chemical shifts of a solvent used for the measurements is found, based on the temperature distribution in the sample tube. Shimming is done using magnetic field gradients based on the distribution of the chemical shifts of the solvent.

Abstract: There is disclosed an NMR (nuclear magnetic resonance) spinner having a turbine structure and a rotor whose spinning rate can be increased. A vortical channel (44) is formed around the rotor (12). The vortical channel (44) consists of a chamber (66) and a nozzle array (68) mounted inside the chamber (66). The chamber (66) has a cross-sectional area that decreases in an upstream to downstream direction. The cross-sectional area of each nozzle also decreases in an upstream to downstream direction. Gas is introduced into the chamber (66), creating a rotating flow (76, 78, 80) in the chamber (66). Plural inwardly swirling streams are created from the inside of the rotating flow. The inwardly swirling streams are ejected from the exits of the nozzles. This results in jet streams, which are blown against the impeller of the rotor, spinning the rotor at high speed.

Abstract: A method of NMR measurement which achieves background suppression based on a technique employing differences in RF magnetic field strength while alleviating the problem that less latitude is allowed in setting the number of signal accumulations. This method suppresses a background-derived signal emanating from the material of an NMR probe. The method starts with applying an RF pulse sequence consisting of a 90° pulse and subsequent one or more 180° pulses to a sample to induce an NMR signal and detecting the signal. This application is repeated while varying the RF phases of the pulses to induce NMR signals in accordance with a cogwheel phase-cycling scheme to induce NMR signals. The NMR signals are detected. The detected NMR signals are accumulated.

Abstract: An NMR (nuclear magnetic resonance) detection module (such as an NMR probe) mounted in a vacuum vessel permits a transmit/receive coil to be cooled efficiently and to be placed closer to a sample container. The NMR detection module includes a core module (detection module) (54) consisting of a refrigerant block (118) and a transmit/receive coil formed on the inner surface of a detection hole (130). A sleeve (cylindrical partition wall) (122) forming a part of the vacuum vessel is inserted in the detection hole (130). A sample tube (56) is inserted in the sleeve (122). The refrigerant block (118) is connected to a heat exchanger via a support member (82). Since it is not necessary to form a bobbin inside the transmit/receive coil, the distance between the coil and the sample can be set small. The coil is entirely surrounded by the refrigerant block.

Abstract: A cooled NMR detection probe including a detection coil and an internal structure (65) mounted in a vacuum vessel (58) includes a radiation shield assembly (68), a connecting member (74), and a heat exchanger (80). The internal structure (65) is secured to the vacuum vessel (58) by a holding member (66). If the internal structure shrinks during cooling, the position of an upper portion of the first heat exchanger (80) hardly varies, thus suppressing displacement of a core module (54).

Abstract: An NMR sample tube is offered which can be spun at high speed stably. The NMR sample tube is adapted for use in solid-state NMR spectroscopy and includes a tubular member, spacers, and cover bodies. The spacers are disposed inside the tubular member. Each spacer has first and second surfaces located on opposite sides. The first surfaces of the spacers define a space filled up with a sample. The tubular member has openings which are closed off by the cover bodies.

Abstract: A method is offered which permits NMR measurements of integer spin nuclei to be performed at higher sensitivity than heretofore. In particular, the method enables high-resolution multidimensional correlation NMR measurements on integer spin nucleus S having integer spin S and nucleus I of other spin species. The method starts with applying an RF magnetic field having a frequency that is n times (where n is an integer equal to or greater than 2) the Larmor frequency of the integer spin nucleus S to the spin S. Magnetization transfer is effected between the nucleus I and the integer spin nucleus S.

Abstract: An NMR probe has a sample tube insertion port for introducing and withdrawing the sample tube into and from the probe, a sample tube support providing support of the sample tube during NMR measurements, a tubular sample tube passage connecting together the sample tube insertion port and the sample tube support and capable of transporting the sample tube between them, and a gas stream generator for producing a gas stream in the sample tube passage to move the sample tube between the sample tube insertion port and the tube support. The gas stream generator is mounted at an intermediate (non-end) position in the sample tube passage.

Abstract: An NMR spectrometer and method in the following three steps are performed. (1) An external magnetic field is set to H0+?H (where 4H>0). When the detection coil made of the superconducting material is still in a normal state, a magnetic field stronger than the ultimate target static magnetic field strength H0 by ?H is applied to the detection coil. (2) The detection coil made of the superconducting material is cooled down to T0 lower than its critical temperature Tc to bring the coil into a superconducting state while the external magnetic field H0+?H is applied to the detection coil. (3) The external magnetic field is lowered from H0+?H to H0 such that the applied external magnetic field is decreased by ?H while the detection coil is kept in the superconducting state.

Abstract: A transmit-receive switching circuit is offered which is for use in an NMR spectrometer that employs a solid-state NMR probe using a cooled detection coil. The switching circuit is cryogenically cooled to reduce thermal noise in use. The switching circuit has a first terminal for applying high-power RF pulses sent in from the power amplifier of the NMR spectrometer, a second terminal for sending the RF pulses applied from the first terminal to the NMR detector via crossed-diodes and for receiving and entering a low-power NMR signal detected by the NMR detector, and a third terminal for sending the NMR signal entered from the second terminal toward a preamplifier. Plural stages of shunts are connected to the transmission line connecting the second and third terminals such that one stage of shunt corresponds to a 90° phase shift in the RF radiation.

Abstract: A high-resolution solid-state NMR spectrometer which can measure a disklike sample. The spectrometer includes: a stator having an air bearing disposed within the static magnetic field, the rotor being disposed in the stator; and an engaging mechanism mounted in a one-end portion of the rotor and detachably holding a sample holder that holds the disklike sample.

Abstract: In a nuclear magnetic resonance (NMR) spectrometer, a sample spins about an axis tilted at a magic angle, a corrective magnetic field generating portion produces a corrective magnetic field, and a control portion controls the operation of the corrective magnetic field generating portion. An arithmetic unit included in the control portion uses at least one of BZ(1), B1(1)e, and B1(1)o or the linear sum of at least two of them as the first-order magnetic field component of the corrective magnetic field, uses at least one of B2(2)e, B2(2)o, B2(1)e, and B2(1)o or the linear sum of at least two of them as the second-order magnetic field component of the corrective magnetic field, and uses at least one of BZ(3), B3(1)e, B3(1)o, B3(2)e, B3(2)o, B3(3)e, and B3(3)o or the linear sum of at least two of them as the third-order magnetic field component of the corrective magnetic field.

Abstract: A method of controlling the static magnetic field in an NMR spectrometer in such a way that the magnetic field can be homogenized even if there is a temperature gradient across a sample tube. A distribution of resonance frequencies and chemical shift differences within the sample tube is found by NMR measurements for each of two peaks of a calibration sample. A temperature distribution is found based on the distribution of the chemical shift differences. A distribution of chemical shifts of a solvent used for the measurements is found, based on the temperature distribution in the sample tube. Shimming is done using magnetic field gradients based on the distribution of the chemical shifts of the solvent.

Abstract: An NMR measurement method adapted for measurements on solid mixture samples starts with irradiating a pulse sequence to the sample in order to measure the longitudinal magnetization relaxation times of nuclei possessing homogeneous longitudinal magnetization relaxation times (step 1). After a lapse of a given period of time t, a high-resolution NMR spectrum is acquired by nullifying spin diffusion across the nuclei (step 2). The steps 1 and 2 are repeated while varying the period of time t. The high-resolution NMR spectra are classified according to value of longitudinal magnetization relaxation time by inverse Laplace transform.

Abstract: A spectrometer has: Accumulation means to obtain a data set containing N data points, repeating the measurement M times to obtain M spectral data sets or time-domain data sets S1 (d1 to dN) to SM (d1 to dN), and accumulating the M spectral data sets or time-domain data sets. Means for creating sets S1 (dn) to SM (dn) of the data points contained in the M spectral data sets or time-domain data sets S1 (d1 to dN) to SM (d1 to dN). Correlation computing means for finding correlations. Computing means for finding either the product of an accumulated or anticipated spectrum.