The signal is observed at the end of two consecutive pulses with quadrature phases.
References containing data and graphs that can be simulated with the spin-locking applets, in order to determine the quadrupole coupling from a featureless NMR lineshape, are provided:
S. Z. Ageev, P. P. Man, and B. C. Sanctuary
Detection of double and four quantum coherences for spin 7/2 excited by spin lock pulse sequences (PDF article, 160 Kb),
J. Magn. Reson. 128, 12-20 (1997).
P. P. Man
Detection of double-quantum coherences in a spin-5/2 system excited by spin-lock sequences (PDF article, 428 Kb),
J. Magn. Reson. A 113, 40-46 (1995).
P. P. Man
Double-quantum coherence detection in a spin-3/2 system excited by two consecutive pulses (PDF article, 491 Kb),
Mol. Phys. 76, 1119-1129 (1992).
SIMPSON scripts and Mathematica-5 notebooks
Use Wolfram CDF Player to read Mathematica notebook in modern web browser.
- Effet of offset on spinlock 90°(X)90°(Y) pulse for positive gyromagnetic ratio nucleus:
magnetization x component,
magnetization y component,
magnetization z component,
corresponding Mathematica 5 notebook.
- Composite rotation matrices in Mathematica-5 notebook:
passive rotation about rotated axes,
active rotation about rotated axes.