Attempts to suppress spin diffusion in relaxation measurements

9 Attempts to suppress spin diffusion in relaxation measurements 

We have seen in section 7.8 that these techniques have been widely used in the preparation and detection phases of spin-diffusion experiments, but they have also found application elsewhere. Spin-locking at the magic angle has been used to derive estimates for the lower limits of intrinsic relaxa- 

Proton relaxation under multiple pulse conditions has also been used to characterise phase composition in, for example, PET [95,96], and polyethylene [120]. The technique is particularly useful in the case of PET because the phases present generally do not show large differences in the decay times of their FID components, so FID analysis would be particularly problematic. Although the problem of assessing the extent to which spin diffusion is suppressed also applies to relaxation under multiple pulse conditions, the available experimental evidence suggests that they may be more effective in practice than the corresponding off-resonance spin-locking experiment [96]. This is almost certainly due to practical considerations rather than theoretical ones. 

---