Fourier transform microwave observation of SO (X 3Σ, v=0–2) produced by 193 nm photodissociation of SO2 in a pulsed supersonic jet expansion

SO (X 3Σ) radicals have been produced by 193 nm photodissociation of SO2 in a pulsed supersonic free jet expansion in Ar and detected using a molecular beam–Fourier transform microwave spectrometer with a semi-confocal cavity. The performance of the spectrometer was optimized by recording the SO (X 3Σ) microwave spectrum near 13000 MHz. The J=1←1, N=2←1 transition of 32SO was observed with a signal-to-noise ratio of 10 in a single photolysis laser and microwave shot. The corresponding spectrum of 34SO was recorded with 34S in natural abundance (4.2%).