Density of O-atoms in an Afterglow Reactor During Treatment of Wool

Density of neutral oxygen atoms in the ground state has been measured during treatment of wool fabric samples. Samples were placed in an afterglow reactor with a volume of about 5 l, which was pumped with a two stage rotary pump with the nominal pumping speed of 28 m³/h. The source of the oxygen atoms was a microwave discharge operating in the surfatron mode at 2.45 GHz and adjustable output power up to 300 W. The density of O-atoms in the afterglow chamber was measured with a fiber-optics catalytic probe. For the empty reactor, the O density depended on discharge parameters and was between 0.8 and 2.8 × 10²¹ m⁻³ at 40 and 50 Pa respectively. During the treatment of wool, the O density depended largely on the exposure time. For untreated samples, the O density was below the detection limit of the probe, while prolonged treatment allowed for recovering the O density. The recovery always occurred after having submitted wool samples to the dose of the order of 10²³ atoms/m². The results were explained by oxidation of the thin lipid layer on the surface of the wool fibres.