Hostname: page-component-848d4c4894-nr4z6 Total loading time: 0 Render date: 2024-05-16T07:05:10.166Z Has data issue: false hasContentIssue false
  • English
  • Français

Kinetic Monte Carlo simulations of the grain-surface back-diffusion effect

Published online by Cambridge University Press:  04 September 2018

Eric R. Willis Open the ORCID record for Eric R. Willis [Opens in a new window]  and
Robin T. Garrod
Eric R. Willis
Affiliation:
Department of Chemistry, University of Virginia Charlottesville, VA 22904-4319 email: ew2zb@virginia.edu
Robin T. Garrod
Affiliation:
Department of Chemistry, University of Virginia Charlottesville, VA 22904-4319 email: ew2zb@virginia.edu Department of Astronomy, University of Virginia Charlottesville, VA 22904-4325
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Back-diffusion is the phenomenon by which random walkers revisit binding sites on a lattice. This phenomenon must occur on interstellar dust particles, slowing down dust-grain reactions, but it is not accounted for by standard rate-equation models. Microscopic kinetic Monte Carlo models have been used to investigate the effect of back-diffusion on reaction rates on interstellar dust grains. Grain morphology, size, and grain-surface coverage were varied and the effects of these variations on the magnitude of the back-diffusion effect were studied for the simple H+H reaction system. This back-diffusion effect is seen to reduce reaction rates by a maximum factor of ∼5 for the canonical grain of 106 binding sites. The resulting data were fit to logarithmic functions that can be used to reproduce the effects of back-diffusion in rate-equation models.

Keywords

astrochemistryISM: moleculesmethods: numerical
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 13 , Symposium S332: Astrochemistry VII: Through the Cosmos from Galaxies to Planets , March 2017 , pp. 370 - 373
Copyright
Copyright © International Astronomical Union 2018 

References

Chang, Q., Cuppen, H. M., & Herbst, E., 2005, A&A, 434, 599Google Scholar
Garrod, R. T., 2008, A&A, 491, 239Google Scholar
Garrod, R. T., 2013, ApJ, 778, 158Google Scholar
Lohmar, I. & Krug, J., 2009, J. Stat. Phys., 134, 307Google Scholar
Pedersen, A., Wikfeldt, K. T., Karssemeijer, L., Cuppen, H., & Jónsson, H., 2014, J. Chem. Phys., 141, 234706Google Scholar