title: Photoemission from sodium on ice: a mechanism for positive and negative charge coexistence in the mesosphere.
abstract: Photoemission from sodium deposited on ice films is described. Deposition of 0.02 ML of sodium is found to dramatically reduce the threshold for photoemission from the ice film to (2.3+/-0.2) eV. Thus, the cross-section for photoemission reaches >10(-18) cm2 in the visible region of the spectrum. It is proposed that the initial state is a solvated electron on the ice surface, which is supported by optical transmission spectroscopy. The potential significance of these results in understanding unexplained charging phenomena in the mesosphere is discussed.
authors.affiliation: School of Environmental Sciences and School of Chemical Sciences and Pharmacy, University of East Anglia, Norwich NR4 7TJ, UK.
authors.forename: Tomas
authors.initials: T
authors.lastname: Vondrak
authors.forename: John M C
authors.initials: JM
authors.lastname: Plane
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Meech
mesh_terms: D001272:Atmosphere / Q000737:chemistry*; D007053:Ice; D008027:Light; D010777:Photochemistry; D017785:Photons; D012964:Sodium / Q000737:chemistry* / Q000528:radiation effects*; D013499:Surface Properties; D013696:Temperature
chemical_list: D007053:Ice; D012964:Sodium