Kinetic studies of Ar–N2–SF6 mixtures following proton excitation

Abstract

Time resolved studies h!ve b%en made of both the vacuum ultraviolet (vuv) and the uv-visible radiation due to pulsed proton excitation of Ar–N2, Ar–SF6, and Ar–N2–SF6 mixtures. Photon emissions from Ar and from N2 (due to energy transfer from Ar) were both studied, using time resolved spectroscopic techniques. In the Ar–N2 mixtures the decay of N2(C 3Πu→B 3Πg) is much slower than the natural lifetime of N2(C 3Πu). In the case of the (0–1) band for the transition N2(C 3Πu→B 3Πg), the decay follows Ar(3P2); while the decay of the (3–1) band follows that of Ar(1P1). Decay rates of (1–0) and (2–1) are between the decay of Ar(1P1) and Ar(3P2). From least squares fitting, it was found that 68% of v′=2 of N2(C 3Πu) comes from Ar(1P1) and 32% from Ar(3P2); while 86% of v′=1 comes from Ar(3P2) and 14% from Ar(1P1). Since the energy precursor of N2(C 3Πu)v′=3 is Ar(1P1), it is clear that the Wigner spin conservation rule does not hold rigorously in this energy transfer process. Quenching rates of Ar(1P1), Ar(3P2), Ar(3P1) and Ar2(1u) by SF6 have also been determined. Gas laser applications are discussed briefly.