%0 Journal Article %T Nonlinear NMR dynamics in hyperpolarized liquid 3He %A Emmanuel Baudin %A Michael E. Hayden %A Genevi¨¨ve Tastevin %A Pierre-Jean Nacher %J Physics %D 2007 %I arXiv %X In a highly polarized liquid (laser-polarized 3He-4He mixtures in our experiment), dipolar magnetic interactions within the liquid introduce a significant nonlinear and nonlocal contribution to the Bloch equation that leads to instabilities during NMR evolution. We have launched a study of these instabilities using spin echo techniques. At high magnetizations, a simple 180 degree rf pulse fails to refocus magnetization, so we use a standard solid-state NMR pulse sequence: the magic sandwich. We report an experimental and numerical investigation of the effect of this sequence on unstable NMR evolution. Using a series of repeated magic sandwich sequences, the transverse magnetization lifetime can be increased by up to three orders of magnitude. %U http://arxiv.org/abs/0710.3567v2