Pulse Sequences and Experiments

However, some aspects of the spin dynamics are better described using functions other than Fourier series. For example, the magnetization decay in a CPMG [28] experiment follows an exponential form, 

In the following sections, we will discuss several examples of the 2D NMR pulse sequences to illustrate the essential aspects required to obtain the correlation functions of relaxation and diffusion. 

During the Xi and x2 periods, the spin system experiences spin relaxation along the direction of and transverse to the magnetic field, respectively. 

Diffusion-relaxation correlation has been utilized to study biological tissues, e.g., compartmentalization in tissues [32-35]. In many reports, a sequence that combines a stimulated echo-type sequence with a pulsed field gradient and a CPMG as a detection has been described [35]. Other pulses sequences have also been used to study the diffusion-relaxation correlation, e.g., Ref. [36]. 

For the case of the spin-echo for diffusion weighting, the full kernel can be written as 

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