Quasistationary magnetization in pulsed spin-locking experiments in dipolar solids

Abstract

The quasistationary magnetization in dipolar solids for pulsed spin-locking experiments is calculated. A temporary equilibrium after several pulses is assumed to develop under a Hamiltonian obtained with average Hamiltonian theory from the terms for the rf field and the dipolar interaction. The effect of finite pulse width is discussed. Experimental data from a Ca${\mathrm{F}}_{2}$ sample support the theoretical results. It is shown that pulse flip angles ${\ensuremath{\varphi}}_{x}=180\ifmmode^\circ\else\textdegree\fi{}\ifmmode\pm\else\textpm\fi{}\ensuremath{\epsilon}$ have the same effect as the flip angle $\ensuremath{\epsilon}$.