HR: 0800h
AN: P11B-0111    [Abstracts]
TI: Effects of Ion Irradiation on Ice Porosity and Gas Adsorption
AU: * Raut, U
EM: ur5n@virginia.edu
AF: Laboratory for Atomic and Surface Physics University of Virginia, 116 Engineer's Way, Charlottesville, VA 22904 United States
AU: Teolis, B D
EM: bdt4z@virginia.edu
AF: Laboratory for Atomic and Surface Physics University of Virginia, 116 Engineer's Way, Charlottesville, VA 22904 United States
AU: Loeffler, M J
EM: mjl8r@virginia.edu
AF: Laboratory for Atomic and Surface Physics University of Virginia, 116 Engineer's Way, Charlottesville, VA 22904 United States
AU: Baragiola, R A
EM: raul@virginia.edu
AF: Laboratory for Atomic and Surface Physics University of Virginia, 116 Engineer's Way, Charlottesville, VA 22904 United States
AB: We have studied the effects of ion irradiation on the
porosity of amorphous ice using infrared and ultraviolet-
visible (uv-vis)spectroscopy. Our findings indicate that
ion irradiation induces compaction in porous ice.
The density of the ice films rises asymptotically to a
saturation value with increasing ion fluence. Irradiation
also decreases the intensity of the near 2.71 μm
absorption features assigned to O-H stretch in dangling
water molecules present in porous ice films. However, we
find that the ion fluence required for disappearance of the
dangling O-H stretch absorption features can only partially compact the ice films. Low fluence irradiation
(< 10¹³ ions/cm²) can transform pristine ice films
such that it retains significant porosity (~ 50 %)
but lack water molecules with dangling bonds. We also
performed a series of experiments with methane on ice films
to investigate the effects of the dangling water molecules on gas
adsorption and desorption.
DE: 5422 Ices
DE: 5470 Surface materials and properties
DE: 6020 Ices
DE: 6055 Surfaces
SC: Planetary Sciences [P]
MN: Fall Meeting 2005