The primary application of TPEPICO is the production of internal energy selected ions to study their unimolecular dissociation dynamics as a function of internal energy.  The electrons are extracted by a continuous electric field and are velocity map imaged depending on their initial kinetic energy. Ions are accelerated in the opposite direction and their mass is determined by time-of-flight mass spectrometry. The data analysis yields dissociation thresholds, which can be used to derive new thermochemistry for the sample.
The electron imager side can also be used to record photoionization cross sections, photoelectron energy and angular distributions. With the help of circularly polarized light, photoelectron circular dichroism (PECD) can be studied. A thorough understanding of PECD effects could help explain the homochirality of life. Flash pyrolysis can also be used to produce free radicals or intermediates, which are then characterized to complement e.g. combustion studies. In such cases, the photoion mass analysis is used to confirm the identity of the radical produced.
Photoelectron photoion coincidence spectroscopy can be used to shed light on reaction mechanisms, and can also be generalized to study double ionization in (photoelectron) photoion photoion coincidence ((PE)PIPICO), fluorescence using photoelectron photon coincidence (PEFCO), or photoelectron photoelectron coincidence (PEPECO). Times-of-flight of photoelectrons and photoions can be combined in a form of a map, which visualizes the dynamics of the dissociative ionization process. Ion–electron velocity vector correlation functions can be obtained in double imaging setups, in which the ion detector also delivers position information.