Publications Details

Revisiting spontaneous Raman scattering for direct oxygen atom quantification

Van De Steeg, A.W.; Vialetto, L.; Silva, A.F.; Peeters, F.J.J.; van den Bekerom, Dirk C.; Gatti, N.; Diomede, P.; Van De Sanden, M.C.M.; Van Rooij, G.J.

In this Letter, the counterintuitive and largely unknown Raman activity of oxygen atoms is evaluated for its capacity to determine absolute densities in gases with significant O-density. The study involves CO2 microwave plasma to generate a self-calibrating mixture and establish accurate cross sections for the 3P2↔3P1 and 3P2↔3P0 transitions. The approach requires conservation of stoichiometry, confirmed within experimental uncertainty by a 1D fluid model. The measurements yield σJ =2→1 = 5.27 ±randsys:0.53:0.17 ×10−31 cm2/sr and σJ =2→0 = 2.11 ±randsys:0.21:0.06 ×10−31 cm2/sr, and the detection limit is estimated to be 1 × 1015 cm−3 for systems without other scattering species.