Fig. 3: Highly accelerated observation of spin order transfer in EP-d6 during PHIP at 0.55 T.
In-phase PHIP signal simulated for 45o out-of-phase spin echo sequence with n refocusing elements and τ intervals (45o-sOPE(n,τ), a, b) and experimentally measured signals (c, d) using a 45o-CPMG sequence as a function of \(\tau\) and a number of echoes \(n\) (a, c), or as a function of \(\tau\) and \(2n\tau\) (b, d). The simulations were well reproduced by the experiments and helped to identify parameters suited for the spin order transfer. Here, each line in the polarization transfer map (c) was measured using one sample, while 100 would be necessary with conventional 45o-OPE. Simulations: only two protons were considered; chemical shifts and J-coupling constants are given in methods; relaxation and magnetic field inhomogeneity were not considered; duration of the 90o and 180o pulses were 30 μs and 60 μs, respectively. Experiments: samples were prepared by mixing [Rh] = 3 mM with 50 mM of vinyl pyruvate-d6 (VP-d6) in acetone-d6; the pH2 pressure was 15 bar; the signal decayed due to relaxation, imperfect refocusing RF pulses, diffusion, and oscillation of the external magnetic field; the durations of the 90o and 180o pulses were 33 μs and 66 μs, respectively. Analogous maps were measured for EA-d6 and EC (Supplementary Figs. 2 and 3). The 45o-CPMG values shown in Fig. 2b are taken from (c) for n = 3.
