Simple two-pulse time-reversal sequence for dipolar and quadrupolar-coupled spin systems.

Abstract We demonstrate, both theoretically and experimentally, that two-pulse sequence (2 n +1)·90 Y °−90 X °− Acq ( t ) without delay between pulses, yields the reverse of time evolution of spin system with dipolar and quadrupole interactions. This process results in refocusing of the spin magnetization into magic echo at t e = t 1 /2 after the second pulse, where t 1 is the length of the first pulse.