Rate Constants for Unimolecular Decomposition of SF6-

Published

November 21, 2001

Author(s)

Yicheng Wang, R. Champion, I. V. Dyakov, B. Peko

Abstract

Insulating gas mixtures containing SF₆ have been promoted to serve as replacements for pure SF₆ in order to reduce SF₆ atmospheric emission. It has been argued that some synergism may be achieved by choosing proper buffer gases in mixtures with SF₆ such that the buffer gases efficiently slow down electrons into an energy range where the electron attachment cross section for SF₆ is large. A complete understanding of the dielectric properties of SF₆ mixtures obviously requires information about electron detachment from SF₆- as collisional electron detachment may be the principal source of discharge initiation in SF₆ mixtures. In this paper, we report rate constants for collision-induced decomposition of SF₆- modeled with a two-step mechanism in which collisional excitation of SF₆- to SF₆-* is followed by unimolecular decomposition of SF6-*. Unimolecular decomposition rates are based on recent thermochemical data and a statistical model first proposed by Klots [1]. The model results will be compared with the recently measured total cross sections for electron detachment and collision-induced dissociation for SF₆- + N₂. [1]. C.E. Klots, Chem. Phys. Lett. 38, 61 (1976).

Proceedings Title

Proc., Intl. Symp. on Gaseous Dielectrics

Conference Dates

May 21-25, 2001

Conference Location

Denver, CO, USA

Conference Title

9th International Symposium of Gaseous Dielectrics

Pub Type

Conferences

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Keywords

decomposition, negative ions, SF₆, sulfur hexafluoride

Citation

Wang, Y. , Champion, R. , Dyakov, I. and Peko, B. (2001), Rate Constants for Unimolecular Decomposition of SF₆-, Proc., Intl. Symp. on Gaseous Dielectrics, Denver, CO, USA, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=17369 (Accessed December 8, 2024)