| 摘要 |
PURPOSE:To perform the high speed collection of NMR data, by impressing the gradient magnetic field for satisfying a prescribed condition before and after 180 deg. pulse impression. CONSTITUTION:Current is passed through a coil 1 for static magnetic field from a control circuit 2 to give a static magnetic field H0. Current is passed through a coil 31 for Z gradient magnetic field from a controller 20 through a control circuit 4, 90 deg. X pulse is given while giving Z gradient magnetic field Gz<+> to select and excite a body to be inspected. A magnetic field Gz<-> is impressed successively to G<+> impressing. Next, magnetic fields Gx, Gy are impressed for a prescribed time. Next, the magnetization is turned over by 180 deg. pulse through a gate circuit 30. Above operations are repeated so that the fields Gx, Gy before and after 180 deg. pulse impressing satisfy next equation. gxpXtmp=g'xpXt'mp, gypX tmp=g'ypXt'mp, p=1-n, n is number of 180 deg. pulse, g, g' are intensity, x y are phase of RF pulse, tmp, t'mp are impressing time of gradient magnetic field before and after 180 deg. pulse impressing. Thereby, high speed collection of NMR data is made possible. |
