Unveiling ion-impact-induced fragmentation dynamics of atoms, molecules, and clusters using the COLTRIMS reaction microscope

Over the past 30 years, cold target recoil ion momentum spectroscopy (COLTRIMS) has emerged as a pivotal technique for investigating atomic and molecular interactions under charged particle impacts. By enabling the coincident detection of all correlated fragments with high momentum resolution, COLTRIMS has expedited detailed investigations of atomic and molecular collision processes such as electron capture, ionization, fragmentation, and energy transfer in various few-body systems. This technique has significantly advanced our understanding of quantum correlations, wavefunction entanglement, and reaction-pathway dynamics in various atomic, molecular, and cluster targets. Further technological advances-such as reaction microscopes, which enable the simultaneous detection of both electrons and ions; high-speed position-sensitive detectors; and sophisticated data analysis methods-have broadened the range of COLTRIMS-based experiments to include more complex systems, such as biomolecules and condensed-phase targets. This review offers a comprehensive overview of the significant discoveries made possible by COLTRIMS in studies involving ion beam impacts, highlights recent technical innovations, and discusses emerging research directions in this field.