Electron-impact studies of atomic oxygen: II. Emission cross section measurements of the O<scp>I</scp>³S^<i>o</i>→³P transition (130.4 nm)

Abstract

The optical excitation function of the O I 3So→ 3P transition (130.4 nm), produced by electron-impact excitation of atomic oxygen, has been measured over an extended energy range from threshold to 1.0 keV. Measurements were obtained in a crossed-beam experiment using both magnetically confined and electrostatically focused electrons in collision with atomic oxygen produced by a microwave discharge source. A 0.2 m vacuum ultraviolet monochromator system was used to measure the emitted O I radiation at 130.4 nm. The relative O I (130.4 nm) emission intensity corresponding to the 3So→ 3P transition was then put on the absolute scale by normalization to the O I (130.4 nm) cross section produced by dissociative excitation of O2 at 30 eV (Kanik et al 2000).