Ozone is generated by injecting a flow of oxygen or oxygen enriched air into a corona discharge zone formed between concentric inner tubular electrode/dielectric and outer tubular electrode. The dielectric of the tubular electrode/dielectric has a sealed end. The feed stream of oxygen or oxygen enriched air is injected by a tubular gas injector having an inlet end to accept the oxygen or oxygen enriched air and outlet end to inject the oxygen or oxygen enriched air within the inner concentric electrode/dielectric in proximity to the sealed end to flow the length of the inner concentric electrode/dielectric to the corona discharge zone for conversion of oxygen to ozone.