The reactivity of isolated ions in a mass spectrometer, when experimental conditions are precisely controlled, allows access to the elementary act of chemical reactions. This approach is of great interest for practical applications, such as understanding processes in industrial plasmas or developing new selective ionization sources, where an excess ion reacts specifically with trace molecules, enabling highly sensitive detection.

This scientific axis, "Reactivity of Ions," is led by Christian Alcaraz. We focus particularly on:

• • • • • • • • The effects of internal energy and collision, for astrochemistry and industrial plasma chemistry.
              • The ionic pathway that can form peptide bonds in the interstellar medium.
              • The reactivity induced in pollution abatement plasmas through real-time analysis.