Downloads

Disclaimer

The pulse sequences/pulse shapes provided in Bruker format on this site were tested on Bruker AVANCE spectrometers at the Bavarian NMR Center, Munich. However, the sequences are made available without any expressed warranty. We are not liable for any potential damage that might me caused in connection with the pulse programs.

Optimal control pulse sequences for homonuclear three-spin systems (J. Neves et al., 2006)

Theoretical control amplitudes shown in Fig. 1 in the idealized setting described in the paper (c.f. Eqs. 6 and 7) for polarization transfer I1z to I2z. For the isotropic coupling constants J12=1Hz and J13= J23= - 2.4 Hz the optimized local control amplitudes u1x(t), u1y(t), u2x(t), u2y(t), u3x(t), and u3y(t) are given (in Matlab format) for a total transfer time of 0.32 s. The pulse sequence is digitized in 200 time steps of duration 0.016 s. The control amplitudes are given in units of Hz.

Optimized practical phase-modulated pulse shapes (in Bruker format) with a constant rf amplitude of 10.125 kHz and durations of 19.9 ms (c.f. Fig. 7A), 26.7 ms, 28.4 ms, 39.8 ms, and56.8 ms optimized for offset variations of +/- 170 Hz around the offsets of 13C spins of alanine at a 13C transmitter frequency of 62.5 MHz. The corresponding simulated and experimental polarization transfer amplitudes crom C_beta to C' are represented in Fig. 6 by solid and open circles, respectively. (It should be noted that all pulse phases phi have been replaced by (360 - phi) in order to be consistent with Bruker conventions). The time increment is 30 micro seconds.