Regular Article

Electron impact ionization and cationic fragmentation of the pyridazine molecules^★

¹ Department of Physics of Electronic Phenomena, Faculty of Applied Physics and Mathematics, Gdańsk University of Technology, 80-233 Gdańsk, Poland
² Department of Atomic, Molecular and Optical Physics, Faculty of Applied Physics and Mathematics, Gdańsk University of Technology, 80-233 Gdańsk, Poland
³ Department of Control and Power Engineering, Faculty of Ocean Engineering and Ship Technology, Gdańsk University of Technology, 80-233 Gdańsk, Poland

^a e-mail: paw@pg.edu.pl
^b e-mail: marzubek@pg.edu.pl

Received: 7 September 2018
Received in final form: 27 September 2018
Published online: 18 December 2018

Abstract

Electron impact mass spectroscopy was used to investigate ionization and cationic fragmentation of the pyridazine (1,2 diazine), C₄H₄N₂, molecules in the gas phase. The mass spectra were measured and the observed mass peaks assigned to the corresponding cations. The appearance energies of most of the cationic fragments were determined and the possible fragmentation processes are discussed. The total cross section for electron impact ionization of pyridazine was calculated using the binary-encounter-Bethe (BEB) model. The calculated cross section was applied to normalize the measured cation yield curves and total and partial cross sections for ionization and cationic fragmentation were obtained over the energy range from the respective ionization thresholds to 140 eV.