 Spin–lattice relaxation

Exchange of energy between magnetic spin degrees of freedom and the surrounding lattice, allowing their temperatures to approach thermal equilibrium. It permits adiabatic demagnetization to cool a solid and its attached load.

Spin-lattice relaxation refers to the process by which nuclear spins in a material return to thermal equilibrium with their surrounding lattice after being disturbed, typically by an external magnetic field or radiofrequency pulse. This process is crucial in nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI), as it affects the relaxation times and the overall dynamics of the spin system.