Cold Target Recoil Ion Momentum Spectroscopy: a 'momentum microscope' to view atomic collision dynamics

Cold Target Recoil Ion Momentum Spectroscopy (COLTRIMS) is a novel momentum space imaging technique for the investigation of the dynamics of ionizing ion, electron or photon impact reactions with atoms or molecules. It allows the measurement of the previously undetectable small three dimensional mom entum vector of the recoiling target ion created in those reactions with hi gh resolution and 4 pi solid angle. Combined with novel 4 pi electron momen tum analysers it is a momentum microscope for kinematically complete scatte ring experiments. We review the technical development, outline the kinemati cs of atomic reactions from the perspective of the recoil ion, and give an overview of the studies performed with this technique. These studies yield kinematically complete pictures of the correlated motion of the fragments o f atomic and molecular breakup processes, unprecedented in resolution, deta il and completeness. The multiple-dimensional momentum-space images often d irectly unveil the physical mechanism underlying the many-particle transiti ons investigated. The experiments reviewed here include reactions of single and multiple capture and ionization induced by keV proton to GeV/u U92+ im pact, electron and antiproton impact ionization as well. as single and doub le ionization by photoabsorbtion and Compton scattering from threshold to 1 00 keV. We give an outlook on the exciting future prospects of the method f or atomic physics and other fields of science. (C) 2000 Elsevier Science B. V. All rights reserved.