PURPOSE: To securely perform lock-on operation in a short period by measuring a spectrum for control regarding a nucleus and setting the oscillation frequency of a locking oscillator according to the result.
CONSTITUTION: A sample to be measured in a sample tube 2 and a control sample which contains a nucleus for magnetic field locking are irradiated with an impulsive high-frequency magnetic field which has the resonance frequency of the control nucleus from the oscillator 16 through a transmitting and receiving coil 4. An FID (free inductive decay) signal induced at the transmitting and receiving coil 4 after this pulse irradiation is sampled by an A-D converter 13 through a gate 19, a demodulator 21, and a switch 12, sent to a computer 14, and processed by Fourier transform to obtain a spectrum. The computer 14 performs peak search processing for the spectrum to find the accurate resonance frequency of the control nucleus and set the oscillation frequency of the oscillator 16 to it, thereby controlling the intensity of a polarizing magnetic field.
| JPS63203145 | MAGNETIC RESONANCE IMAGING APPARATUS |
| JPS5998507 | ELECTROMAGNETIC DEVICE |
| JP3339880 | [Title of Invention] Magnetic Resonance Imaging Device |
KAMO OSAMU
HIOKA KATSUYA
IIJIMA MICHIO
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