Negative absolute electron mobility, Joule cooling and the second law
Robson, R.E., Petrovic, Z.Lj., Raspopovic, Z.M., and Loffhagen, D. (2003) Negative absolute electron mobility, Joule cooling and the second law. Journal of Chemical Physics, 119 (21). pp. 11249-11252.
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A number of recent theoretical investigations of electron motion in attaching gases demonstrate the possibility of a steady-state situation in which the electric current opposes the applied field. This phenomenon, which has been called “negative absolute electron mobility”, implies a Joule cooling effect and an associated negative entropy production, suggesting, at first glance, a possible violation of the second law of thermodynamics. In this article we show that the entropy production has in fact two components, the expected negative contribution due to “Joule cooling,” and an additional positive part arising from “attachment heating.” We insist that the total entropy production be positive, in accordance with the second law, and this has the practical implication that the measurable (“bulk”) electron drift velocity must always be positive, even though the actual average (“flux”) velocity may be negative. We discuss the phenomenon physically and take as a numerical example electrons in Ar/F2 mixtures, using Monte Carlo simulation and approximate momentum transfer theory methods to highlight the distinction between the two types of transport coefficient.
|Item Type:||Article (Refereed Research - C1)|
|FoR Codes:||02 PHYSICAL SCIENCES > 0202 Atomic, Molecular, Nuclear, Particle and Plasma Physics > 020201 Atomic and Molecular Physics @ 100%|
|SEO Codes:||97 EXPANDING KNOWLEDGE > 970102 Expanding Knowledge in the Physical Sciences @ 100%|
|Deposited On:||25 Mar 2010 09:26|
|Last Modified:||22 May 2013 01:08|
Last 12 Months: 0
|Citation Counts with External Providers:||Web of Science: 8|
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