We have studied the desorption dynamics of OH radicals from the 157 nm photodissociation of amorphous solid water (ASW) as well as H2 O 2 deposited on an ASW surface at 90 K. The translational and internal energy distributions of OH were measured using resonance-enhanced multiphoton ionization methods. These distributions are compared to reported molecular dynamics calculations for the condensed phase photodissociation of water ice and also reported results for the gas phase photodissociation of H2 O at 157 nm. We have confirmed that OH radicals are produced from two different mechanisms: one from primary photolysis of surface H2 O of ASW, and the other being secondary photolysis of H2 O2 photoproducts on the ASW surface after prolonged irradiation at 157 nm.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry