Slide 10 of 12
Notes:
You might note at this point, that this is yet another pulse sequence with three 90 degree pulses. Again, the specific phase cycling is what distinguishes this experiment from previous ones (such as the DQF-COSY), as the phase cycling selects for the desired coherences, and (ideally) supresses all undesired ones, as well as artifacts due to the relaxation of spins during the pulse sequence (axial peak supression).
As we have already explained the phenomenon of the nOe on the basis of population changes and subsequent relaxation events, and the noesy-experiment does not involve any higher order coherences (at least for the observed signals) we can explain the spin behaviour in the vector model.
