Title

Master Equation for Hydrogen Recombination on Grain Surfaces

Author(s)/Creator(s)

Gianfranco Vidali, Department of Physics, Syracuse University, Syracuse, NY
Ofer Biham, Syracuse UniversityFollow
Itay Furman, The Hebrew University of Jerusalem
Valerio Pirronello, Universita di Catania

Document Type

Article

Date

12-12-2000

Keywords

TBD

Language

English

Disciplines

Physics

Description/Abstract

Recent experimental results on the formation of molecular hydrogen on astrophysically relevant surfaces under conditions similar to those encountered in the interstellar medium provided useful quantitative information about these processes. Rate equation analysis of experiments on olivine and amorphous carbon surfaces provided the activation energy barriers for the diffusion and desorption processes relevant to hydrogen recombination on these surfaces. However, the suitability of rate equations for the simulation of hydrogen recombination on interstellar grains, where there might be very few atoms on a grain at any given time, has been questioned. To resolve this problem, we introduce a master equation that takes into account both the discrete nature of the H atoms and the fluctuations in the number of atoms on a grain. The hydrogen recombination rate on microscopic grains, as a function of grain size and temperature, is then calculated using the master equation. The results are compared to those obtained from the rate equations and the conditions under which the master equation is required are identified.

Additional Information

Latex document. 14 pages of text. Four associated figs in in PS format on separate files that are "called-in" the LaTeX document More information at http://arxiv.org/abs/astro-ph/0012267

Recommended Citation

Vidali, Gianfranco; Biham, Ofer; Furman, Itay; and Pirronello, Valerio, "Master Equation for Hydrogen Recombination on Grain Surfaces" (2000). Physics - All Scholarship. 509.
https://surface.syr.edu/phy/509

Source

Harvested from Arxiv.org