Negative ions are interesting from a fundamental viewpoint. In such loosely bound systems the normally dominant Coulomb interaction between each electron and the core is supressed and the inter-electronic interaction becomes relatively more important. Under such conditions the independent particle model breaks down. Experimental studies of negative ions can therefore serve as a probe of electron correlation effects and hence be used to test theoretical models in order to get better understanding of atomic and molecular processes.
Studies of atomic and molecular negative ions are very interesting for other fields of physics like astrophysics and chemistry as will be emphasized in the following.
Laser Spectroscopy of negative ions at Göteborgs University/Chalmers University.
Electron impact on negative ions at Manne Siegbahn Laboratory.