Experimental study of erosion of methane ice by energetic ions and some considerations for astrophysics

Journal Article · Sun Feb 01 00:00:00 EST 1987 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/165031· OSTI ID:6323030

Lanzerotti, L J; Brown, W L; Marcantonio, K J

The rate of erosion and polymerization of methane ice under bombardment by hydrogen and helium ions, relevant to surface processes on Pluto and possibly Charon and Triton, is studied experimentally as a function of ion energy and ice film thickness. For the thinnest films studied, erosion of the entire film is accomplished using MeV energy helium ions. Loss of both carbon and hydrogen is observed from thicker films, with the hydrogen-to-carbon content of the films decreasing with increasing irradiation exposures. The effective cross section for initial hydrogen loss is about 5 x 10 to the -16th sq cm. After a total incident dose of MeV He ions greater than about 10 to the 15th/sq cm, the loss rates decrease significantly and the effective cross section is about 10 to the -17th sq cm. Thus, the state of ultimate polymerization of a pure methane film in an astrophysical particle environment will depend critically on the thickness of the ice layer as well as on the ion composition of the radiation environment. 33 references.

• Research Organization: AT and T Bell Labs., Murray Hill, NJ
• OSTI ID: 6323030
• Journal Information: Astrophys. J.; (United States), Vol. 313
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
NEPTUNE PLANET
SATELLITES
PLUTO PLANET
SURFACES
ABUNDANCE
EROSION
HELIUM IONS
HYDROGEN
ICE
IRRADIATION
METHANE
THIN FILMS
ALKANES
CHARGED PARTICLES
ELEMENTS
FILMS
HYDROCARBONS
IONS
NONMETALS
ORGANIC COMPOUNDS
PLANETS
640107* - Astrophysics & Cosmology- Planetary Phenomena