Figure 2:

Calculated magnetization versus time in the low-$B_1$ regime. Simulation details: resonance parameters from Table 1; field intensity $B_1=6.3\mu \text{T}$; and, from bottom to top, 20 different sweep rates $d\Delta B_0/dt$ logarithmically distributed between $0.001\text{mT}\mu {\text{s}}^{-1}$ (bottom) to $1\text{mT}\mu {\text{s}}^{-1}$ (top).