New nonlinear laser techniques for studies of negative ions on and off an ion storage ring

New nonlinear laser methods, based on sequential double photoionization, ha ve recently been introduced to the study of structural and dynamic properti es of atomic negative ions; the techniques developed can lead to new experi mental approaches aimed at fundamental problems in atomic physics. We brief ly describe the recent developments related to the investigations of dynami c properties of autoionizing negative ions, nonlinear photoabsorption in th e continuum, and the dynamics of the three-body system in the Wannier-ridge region.