Document Type

Article

Publication Date

5-2017

Abstract

Simulations of a pulsed direct current discharge are performed for a 7% argon in helium mixture at a pressure of 270 Torr using both zero- and one-dimensional models. Kinetics of species relevant to the operation of an optically pumped rare-gas laser are analyzed throughout the pulse duration to identify key reaction pathways. Time dependent densities, electron temperatures, current densities, and reduced electric fields in the positive column are analyzed over a single 20 μs pulse, showing temporal agreement between the two models. Through the use of a robust reaction rate package, radiation trapping is determined to play a key role in reducing Ar(1s5) metastable loss rates through the reaction sequence Ar(1s5)+e− → Ar(1s4)+e− followed by Ar(1s4) → Ar + ℏω⁠. Collisions with He are observed to be responsible for Ar(2p9) mixing, with nearly equal rates to Ar(2p10) and Ar(2p8) ⁠. Additionally, dissociative recombination of Ar2+ is determined to be the dominant electron loss mechanism for the simulated discharge conditions and cavity size.

Comments

© 2017 Author(s), published under an exclusive license with American Institute of Physics.

AFIT Scholar, as the repository of the Air Force Institute of Technology, furnishes the published Version of Record for this article in accordance with the sharing policy of the publisher, AIP Publishing. A 12-month embargo was observed.

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Journal of Applied Physics, 121:203301. as fully cited below and may be found at 10.1063/1.4983678.

Funding notes: This work was supported by the High Energy Laser Joint Technology Office.

DOI

10.1063/1.4983678

Source Publication

Journal of Applied Physics

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