Figure 10.

Dependence of the average steady-state nuclear spin polarization (n_pol,av, solid symbols) and time constant (t_DNP,av, open symbols) on magnetic field for microwave field strengths (ω₁/2π) of 2 MHz (circles) and 80 kHz (diamonds). Calculations were performed for ¹H NMR frequencies of 400.9, 600.0, and 800.0 MHz, with ω_m/2π equal to 264.0, 395.1, and 526.8 GHz, respectively (corresponding to the maximum positive DNP enhancements). The calculations were run for 2000 × t_r (286 ms). Lines are drawn to guide the eye.