Initiation and Microbial-Disinfection Characteristics of Wide-Gap Atmospheric-Pressure Glow Discharge Using Soft X-Ray Ionization

A wide-gap (up to 30 mm) radio frequency (RF) glow discharge was realized at atmospheric pressure, using soft X-ray photo-emission, pre-ionization. The RF glow plasma was excited with an automated matching system, at industrial frequencies (13.56 and 27.12 MHz), in helium or helium-diluted oxygen. Antibacterial effects were examined using spore-forming bacteria: Bacillus atrophaeus, Bacillus subtilis, Geobacillus steamthennophilus, Bacillus pumilis, and selected species of bacteria, a mold, and a yeast-like fungus; Pseudomonas aeroginosa, Salmonella enteritidis, Enterobactor aerogenes, Lactobacillus plantarum, Staphylococcus aureus, Candida albicans, and Aspergillus niger.