| 摘要 |
<p>A method and apparatus for nuclear magnetic resonance for taking a picture of cross section relying upon the scan sequence of the Fourier method to obtain data without being affected by the static magnetic field that changes with the lapse of time. View data G(k, t) for a sample is measured where the spin phase in the sample is twisted in one direction by a given amount, and other view data G(-k, t) of a sample is measured where the spin phase in the sample is twisted in the opposite direction by the same amount within a period of time in which the intensity of static magnetic field changes neglibibly with the lapse of time. From these view data G(k, t) and G(-k, t) are taken data G(k, t0) and G(-k, -t0) at moments t0 and -t0 that are symmetrically relative to each other with respect to the origin of time of these view data. As for the data G(-k, -t0), a complex conjugate G(-k, -t0) is found, and a ratio A = G(k, t0) G(-k, -t0) of the data G(k, t0) to G(-k, -t0) is also found. The measured data is corrected by a signal which varies in proportion to an argument arg (A) of the ratio A.</p> |
