Figure 3.
(a) Pulse sequence used for acquisition of DNP enhanced signals. Following saturation of the 1H and 13C magnetization is a long CW microwave pulse that transfers electron polarization to 1H that is subsequently transferred to 13C for observation. (b) Comparison of enhanced 13C signal and the off-signal, recorded with recycle delays of 10 s and 18 s, respectively. We scale both spectra to the amplitude that would be obtained with an infinitely long recycle delay, based on buildup and T1 data.