title: O(-) from amorphous and crystalline CO2 ices.
abstract: O(-) desorbed from amorphous and crystalline films of CO2 at 18 K under low energy electron impact is studied using time of flight mass spectrometry. The nature of the CO2 film is characterized by Fourier transform infrared spectrometry as a function of film thickness. It is found that the desorption rate from amorphous films is considerably larger than that from crystalline films. The desorption signal from the 4 eV resonance is found to be the dominant one as compared to that from the higher energy resonances, notably the one at 8 eV observed in the gas phase. This is explained in terms of the large enhancement in the dissociative electron attachment cross section for the 4 eV resonance in the condensed phase reported earlier using the charge trapping method.
authors.affiliation: Tata Institute of Fundamental Research, Mumbai-400005, India. ekkumar@tifr.res.in.
authors.forename: Daly
authors.initials: D
authors.lastname: Davis
authors.forename: Sramana
authors.initials: S
authors.lastname: Kundu
authors.forename: Vaibhav S
authors.initials: VS
authors.lastname: Prabhudesai
authors.forename: E
authors.initials: E
authors.lastname: Krishnakumar