Formation mechanisms of oxygen atoms in the O((3)P(J)) state from the 157 nm photoirradiation of amorphous water ice at 90 K.
Desorption of ground state O((3)P(J=2,1,0)) atoms following the vacuum ultraviolet photolysis of water ice in the first absorption band was directly measured with resonance-enhanced multiphoton ionization (REMPI) method. Based on their translational energy distributions and evolution behavior, two different formation mechanisms are proposed: One is exothermic recombination reaction of OH radicals, OH+OH-->H(2)O+O((3)P(J)) and the other is the photodissociation of OH radicals on the surface of amorphous solid water. The translational and internal energy distributions of OH radicals as well as the evolution behavior were also measured by REMPI to elucidate the roles of H(2)O(2) and OH in the O((3)P(J)) formation mechanisms.
Hama
Tetsuya
T
Department of Molecular Engineering, Kyoto University, Kyoto 615-8510, Japan.
Yabushita
Akihiro
A
Yokoyama
Masaaki
M
Kawasaki
Masahiro
M
Watanabe
Naoki
N