Model identification by periodic-orbit analysis for NMR-laser chaos

It is shown that the conventional Bloch-Kirchhoff description of NMR-laser activity needs the inclusion of a nonlinear relaxation term for the transverse magnetization in order to account for the experimental observation. The validity of the modified equations is demonstrated by comparing in a two-parameter space the Poincaré sections and periodic-orbit structures of model and experiment. All unstable orbits up to order nine have been extracted and employed to obtain an approximation to a generating partition.