Furthermore, the DNP transfer ratio of an arbitrary frequency chirp over a given EPR line shape can be calculated by integrating over the EPR line using an approach previously developed by our group . The DNP transfer ratios, 𝐸 ''( and 𝐸 )'( , denote the polarization difference (between electron and nuclear spins) that can be transferred per microwave pulse. As shown in Eq. ( ), the SSE or ASE may reach a DNP transfer ratio greater than 1 when Q is also greater than 1, approaching 𝐸 = 2 for 𝑄 ≫ 1. A large Q value is achieved by applying a strong µw pulse making (ω $& ω !" ⁄ ) large combined with a slow frequency chirp (small 𝜔̇).