Introduction to the relaxation process
The relaxation process refers to the process that the system in equilibrium state can be restored to the original equilibrium state after a certain period of time by the external disturbance.
The time to gradually recover from the non-equilibrium state to the equilibrium state is the relaxation time. After the radio frequency pulse stops, the energy released by the nucleus returns to the thermal equilibrium state. This process is called the relaxation process. This process includes two forms: spin-lattice relaxation and spin-spin relaxation; The time required for the spin-lattice relaxation and spin-spin relaxation processes are denoted by T1 and T2, respectively.