Aromatic molecules revisited under H+ and He2+ collision: theory and experiment

W. WOLF; A. M. P. MENDEZ; S. LOPEZ; C.C. MONTANARI

Congreso; 20th International Conference on the Physics of Highly Charged Ions; 2022

INTERNATIONAL ADVISORY BOARD of the HCI Conference

Aromatic molecules are of multidisciplinary interest such as in bio-, atmospheric-, and astrochemistry, and are considered resistant to fragmentation to ion-impact in the intermediate energy range. Pyrimidine (C4H4N2), pyridine (C5H5N), and benzonitrile (C6H5CN) were selected respectively as representative molecules in the related fields. The importance of measuring the ionization and subsequent fragmentation of such molecules has been stressed in many works associated with hadron-therapy1, cloud formation2, and aromatic hydrocarbon formation in the interstellar medium3. Here, we report the ionization and fragmentation of aromatic molecules under H+ and He2+ collision over a large range of impact energies, from 40 to 150 keV and 700 up to 6000 keV, respectively, using pulsed ion beams and extraction fields combined with a high-resolution time-of-flight spectrometer. Previously, fragmentation cross sections were measured for pyrimidine under proton impact for energies from 300 keV to 16000 keV1. We present theoretical results for the single ionization and electron capture of these species by combining the atomic cross section of its constituents with a stoichiometric approach4. These atomic values were obtained within CTMC and CDW-EIS methods and are examined to probe the importance of the electron capture phenomena at impact energies ranging from 25 keV to 250 keV. Theoretical results and experiments data were revisited searching for collisional and charge state effects on the ionization and break-up channels.