Transition from the C-3-dominated discharge to the sooting plasma - art. no. 026408

Mass spectrometry and photoemission spectroscopy of a graphite hollow catho de source identify the parameters of the transition from the C-3-dominated discharge to the sooting plasma. The transition is a function of the shape and profile of a special cusp magnetic field B-z(r, theta), the geometry of the source, the discharge current, and pressure. Characteristic atomic and molecular emission lines and bands in the C-3 discharge transform into bro ad bands emitted by the excited soot. We identify four prominent emission b ands between 300-400 nm to be the hallmark of the sooting plasma.