De l'ionisation double de l'Ammoniac et du Monoxyde de Carbone. Une comparaison entre les résultats de la photoionisation et de l'impact électronique.

peer reviewedThe double ionization of NH3 and CO2 is investigated by photoionization in the 30-60 eV photon energy range and electron impact from 30-100 eV. The lowest onset for (NH3)2+ formation, measured for the first time by photoionization, is at 34.5+/-0.2 eV. By electron impact this threshold is 34.8+/0.2 eV. For (CO2)2+ this onset is measured at 37.5+/-0.1 eV by photoionization and at 38.0+/-0.1 eV by electron impact. Close to these onsets two double ionization energies are observed: 38.5+/-0.1 eV by photoionization and 39.5+/-0.2 eV by electron impact. These have probably to be ascribed to two different (CO2)2+ states. Higher-lying doubly ionized states of CO2 are detected in the 60-100 eV electron impact energy range