Experimental evidence for two decay channels in electron impact ionization and fragmentation of argon dimer

We study the dissociative ionization of Ar dimer (Ar2) by electron impact with the multiple particles coincidence (electrons and ions) method using a reaction microscope. From the measured kinetic energies of final state electrons and ions, we identify two decay channels which can contribute to the double peak structure in the observed kinetic energy release (KER) spectrum of argon Ar2 dissociating into Ar+- Ar+.