| 摘要 |
A method of performing an NMR investigation on a sample comprising: (1) applying a magnetic field across the sample; (2) applying an rf excitation pulse to the sample; (3) applying a plurality of plane rotation adiabatic fast passage (AFP) rf refocussing pulses along an axis at right angles to the magnetic field; and (4) monitoring a characteristic of the response of the sample. Typically the pulse sequence comprises a CPMG pulse sequence with a first 90 DEG excitation pulse followed by a string of 180 DEG pulses. The first 180 DEG pulse is applied a time tau after the 90 DEG pulse and all subsequent 180 DEG are separated by a time 2 tau . The pulse sequence is particularly suited to NMR well logging or table top medical applications. |
