Precursor feeder for atmospheric pressure plasma jet

A precursor feeder for atmospheric pressure plasma jet includes: a plasma gas nozzle; a feeding passage at a side of the plasma gas nozzle, an annular pressure accumulating chamber having a pressure accumulating region communicated with an outlet of the feeding passage, and having an inner sidewall separating the pressure accumulating region and a plasma region; and a sleeve, adjacent to the annular pressure accumulating chamber and a precursor dissociation region. A truncated conical spout is formed between the sleeve and a edge face of the inner sidewall. An inlet of the truncated conical spout is communicated with the precursor dissociation region at an output end of the plasma gas nozzle. A spout gap of the truncated conical spout of the precursor feeder for atmospheric pressure plasma may be designed as a fixed gap or a movable gap. If the spout gap of the truncated conical spout is the fixed gap, a fixed sleeve may be used. Alternatively, if the spout gap of the truncated conical spout is the movable ga