Abstract: A conversion cell for an ozone generator comprises a first electrode that is hollow and has a right cylindrical internal surface, a second electrode that has a right cylindrical external surface of smaller radius than the internal surface of the first electrode, and an insulator sleeve having coaxial right cylindrical internal and external surfaces. The insulator sleeve is disposed coaxially within the first electrode and the second electrode is disposed coaxially within the insulator sleeve, whereby first and second gas spaces are defined between the insulator sleeve and the first and second electrodes respectively. The first and second gas spaced are sealed at opposite respective ends of the conversion cell and are in open communication with each other.