Fundamentals of Gas-Surface Interactions


Book Description

Fundamentals of Gas–Surface Interactions presents the study of the surface itself and the study of the gas phase partner of the interaction in which physical or chemical transformation of the gas resulted from that interaction. This book discusses the study of the energy and momentum exchanges resulting from the gas–solid physical interaction in which either gas or solid phase properties can be measured. Organized into three parts encompassing 33 chapters, this book begins with an overview of the different sensitive physical methods for the study of surface topography, surface defects, and surface irregularities to an accuracy of a few Angstroms. This text then reviews the adsorption at very low coverage that has yielded to equilibrium analysis. Other chapters consider the measurement of surface area by adsorption and optical techniques. The final chapter deals with scattering processes including momentum and energy transfer. This book is a valuable resource for engineers.

























Monte Carlo Analysis of Lobular Gas-surface Scattering in Tubes Applied to Thermal Transpiration


Book Description

A model of rarefied gas flow in tubes was developed which combines a lobular distribution with diffuse reflection at the wall. The model with Monte Carlo techniques was used to explain previously observed deviations in the free molecular thermal transpiration ratio which suggest molecules can have a greater tube transmission probability in a hot-to-cold direction than in a cold-to-hot direction. The model yields correct magnitudes of transmission probability ratios for helium in Pyrex tubing (1.09 to 1.14), and some effects of wall-temperature distribution, tube surface roughness, tube dimensions, gas temperature, and gas molecular mass.