Abstract: An NMR/ESR antenna is inserted into a magnet device for generating a static magnetic field, and irradiates a sample with an electromagnetic wave to detect a signal generated from the sample. The NMR/ESR antenna comprises a sample tube, an NMR solenoid coil, an ESR microwave cavity, and a microwave guide. The solenoid coil has a central axis coaxial with a central axis of the ESR microwave cavity, and orthogonal to a direction of a main magnetic field generated by the magnetic device.

Abstract: There is providesd a nuclear magnetic resonance spectrometer having a high sensitiveness by simultaneously realizing a high uniformity of a static magnetic field and a high measuring sensitiveness. A sample tube used in the nuclear magnetic resonance spectrometer is constructed in a structure in which the shape of a sample placed in a measuring space can be changed. The change in shape of the sample can be achieved by controlling the pressure applied to the sample. There is at least one surface of contact between the sample placed in the measuring space and a gas existing around the sample, and the shape of such surface is maintained by the surface tension of the sample. In this case, a central portion of a magnet, into which the sample tube is inserted, filled with a sterilizing gas having a pressure higher than the atmospheric pressure, and the sample having a surface of contact with the gas is maintained in a sterile state.

Abstract: An NMR apparatus has a circuit adapted to improve the degree freedom of design and generate an excitation radiofrequency wave pulse suited for a sample to be measured. The radiofrequency wave transmission circuit includes a local oscillator, an IQ modulator having two mixers and two arbitrary waveform generators connected to the IQ modulator. Fourier inverse transform is applied to data inputted to the arbitrary waveform generators.

Abstract: In an NMR measurement method using an NMR apparatus which converts a received signal to digital data using an analog/digital converter and performs a spectral analysis, a folding and aliasing count is decided from a variation in a peak frequency and frequency discrimination is performed. More specifically, a Nyquist frequency is changed to cause a variation of the peak frequency. Since the Nyquist frequency is inversely proportional to an increment of an evolution time t1 which is a feature of multi-dimensional NMR, the Nyquist frequency can be changed by changing the increment of the evolution time. Furthermore, the Nyquist frequency is changed in such a way that a ratio between different Nyquist frequencies is not a ratio between natural numbers n1 and n2 which are greater than 0 and smaller than or equal to the maximum folding and aliasing count.

Abstract: An electromagnetic transceiver apparatus for a NMR apparatus has an intermediate frequency generator for preparing an intermediate wave, a transmission frequency converter for preparing, on the basis of an intermediate frequency of the intermediate wave, an electromagnetic wave to be radiated from a transmitter coil, a reception frequency converter for processing a signal received by the NMR probe, an analog-digital converter for converting an output of the reception frequency converter into a digital signal, an IQ detector for performing detection on the basis of an output of the analog-digital converter, a phase locked loop and a switch inserted between the analog-digital converter and the reception frequency converter to select either an input from the intermediate frequency generator or an input from the reception frequency converter.

Abstract: An NMR apparatus provided with a lock device having improved monotonicity without reducing a control range. In a lock device including a lock transmitter, a lock receiver, a lock detector, a lock corrector, a lock power supply and a lock coil, the lock detector performs complex detection of a detection signal and outputs to the lock corrector an absorption signal SA which is a real number component of the detection signal and a dispersion signal SD which is an imaginary number component of the detection signal; the lock corrector obtains a value SC by multiplying together SD/(SD2+SA2) and a value G, and the lock power supply performs adjustment so that a current flowing through the lock coil is proportional to SC. Different constants G are selectively used according to the value of SD/(SD2+SA2).

Abstract: An NMR apparatus has a circuit adapted to improve the degree freedom of design and generate an excitation radiofrequency wave pulse suited for a sample to be measured. The radiofrequency wave transmission circuit includes a local oscillator, an IQ modulator having two mixers and two arbitrary waveform generators connected to the IQ modulator. Fourier inverse transform is applied to data inputted to the arbitrary waveform generators.

Abstract: There is providesd a nuclear magnetic resonance spectrometer having a high sensitiveness by simultaneously realizing a high uniformity of a static magnetic field and a high measuring sensitiveness. A sample tube used in the nuclear magnetic resonance spectrometer is constructed in a structure in which the shape of a sample placed in a measuring space can be changed. The change in shape of the sample can be achieved by controlling the pressure applied to the sample. There is at least one surface of contact between the sample placed in the measuring space and a gas existing around the sample, and the shape of such surface is maintained by the surface tension of the sample. In this case, a central portion of a magnet, into which the sample tube is inserted, filled with a sterilizing gas having a pressure higher than the atmospheric pressure, and the sample having a surface of contact with the gas is maintained in a sterile state.