The Isotope Effects and the Luminescence Spectra of H2O and D2O Ices Induced by Hydrogen Ions Bombardment
Abstract
We report studies of UV-visible luminescence spectra of amorphous H2O and D2O ices at 30 K irradiated by the H+, $H^{+}_{2}$ and $H^{+}_{3}$ projectiles with a kinetic energy of 15 keV. The observed luminescence features have mainly been attributed to the excited atomic hydrogen, OH radicals, H2O molecules, and possibly O2. The assignments are in line with results reported by other investigators employing low-energy electron impact, ion bombardment, and photon irradiation. The total integrated luminescence intensity between 300 nm and 500 nm from irradiated D2O ices is a factor of four higher than that from irradiated H2O ices. The isotope effects can possibly be due to high predissociation rates in the excitation processes of and effective quenching rates of excited states in the decay processes in H2O. The results obtained are important in our understanding of ice chemistry, chemical evolution, and space weathering in the surfaces of airless objects in our Solar System and beyond.
- Publication:
-
Advances in Geosciences, Volume 15: Planetary Science (PS)
- Pub Date:
- March 2009
- DOI:
- 10.1142/9789812836229_0012
- Bibcode:
- 2009aogs...15..181L