Ionization Relaxation in Shock-Heated Krypton-Argon Mixtures

Abstract

The ionization relaxation processes behind shock waves in pure krypton and krypton-argon mixtures have been investigated using a Mach-Zehnder interferometer technique. The incident shock velocity was fixed in the neighborhood of Us=2800 m/sec, and the initial pressure was fixed at 0.95 Torr. The experimental results were compared with theoretical values based on the two-step collisional ionization model taking into account of the wall boundary-layer effect. The slope constants of excitation cross section against relative kinetic energy between krypton atom-atom collisions, krypton atom-electron collisions, and krypton-argon atom - atom collisions were determined to be 4.2×10⁻¹⁹ cm²/eV, 1.2×10⁻¹⁷ cm²/eV, and 4.2×10⁻¹⁹ cm²/eV, respectively.