Fan-shaped microwave plasma for mail decontamination

A microwave torch is designed to produce fan-shaped plasma, which extends about 140 mm laterally. This torch produces an abundance of reactive atomic oxygen in the plasma effluent as evidenced by its emission spectroscopy. The results of the spectral intensity measurements show that the produced atomic oxygen outside the microwave cavity distributes quite uniformly over a width of about 80 mm and reaches out more than 10 mm. An experiment applying this plasma to kill Bacillus cereus contained in an envelope has been performed. The kill rate is presented.