A glow discharge cell includes an electrically conductive cylindrical vessel, a hollow electrode, a cylindrical screen, a first insulator, a second insulator and a non-conductive granular material. The hollow electrode is aligned with a longitudinal axis of the cylindrical vessel and extends at least from the first end to the second end of the cylindrical vessel. The hollow electrode has an inlet, an outlet, and a plurality of slots or holes. The cylindrical screen is aligned with the longitudinal axis of the cylindrical vessel and disposed between the hollow electrode and the cylindrical vessel to form a substantially equidistant gap between the cylindrical screen and the hollow electrode. The first insulator seals the first end of the cylindrical vessel around the hollow electrode. The second insulator seals the second end of the cylindrical vessel around the hollow electrode. The non-conductive granular material is disposed within the substantially equidistant gap.