Bloch Equation Description with Relaxation Time

In the previous chapter, we considered the Bloch equations without taking into account the relaxation process to provide better visualization of the spin system in the rotating frame. In this chapter, we introduce the foundational concept of NMR, which involves the decay and buildup of net magnetization over time, known as the relaxation term. From the perspective of the Bloch equations, we discuss how the spin-lattice and spin–spin relaxation processes appear in the NMR system.