Relative partial ionization cross sections of N 2O under 10-25-keV electron impact

Abstract

The relative partial ionization cross sections for the fragment ions produced in direct and dissociative ionization of a N 2O molecule are measured for impact of 10-25-keV electrons by using an electron-ion-coincidence technique with a linear time-of-flight spectrometer. The six ionic fragments of N 2O (N 2O +, NO +, N 2 +, O +, N +, and N2 + + O2 +) are observed and identified. The impact energy dependence of the partial ionization cross sections for these ions is expressed relative to the cross section of N 2O + and is found to be nearly invariant. The relative ionic fractions for the produced ions of N 2O are also obtained and compared with the earlier reported data available at lower energies of electron impact. It is found that the relative ionic fractions for singly charged fragments are almost energy independent. However, for the doubly charged fragment ions (N2 + + O2 +), the present data are found to be higher by almost a factor of four compared to the relative ionic fraction reported earlier at a very low impact energy. © 2012 American Physical Society.