An integrated anode and activated reactive gas source for use in a magnetron sputtering device , the integrated anode and reactive gas source comprising: a vessel including: a conductive interior surface , adapted to be electrically coupled, in operation, to a positive output of a power supply, such that it serves, in operation, as an anode providing a voltage difference to a cathode and as a primary return path for electrons; a single opening arranged to communicate, in operation, with a coating chamber of the magnetron sputtering device ; an insulated outer surface arranged to electrically isolate, in operation, the vessel from chamber walls of the coating chamber ; and one or more gas inlet ports ; a source of sputtering gas and a source of reactive gas; wherein one of the one or more gas inlet ports is arranged, in operation, to provide a sputtering gas from the source of sputtering gas into the vessel, and the integrated anode and activated reactive gas source is arranged such that, in operation, the sputtering gas is provided through the single opening of the vessel into the coating chamber ; and wherein one of the one or more gas inlet ports is arranged, in operation, to provide a reactive gas from the source of reactive gas into the vessel, and the integrated anode and activated reactive gas source is arranged, in operation, to activate the reactive gas within the vessel and is arranged such that, in operation, the activated reactive gas is provided through the single opening of the vessel into the coating chamber . a vessel including: a conductive interior surface , adapted to be electrically coupled, in operation, to a positive output of a power supply, such that it serves, in operation, as an anode providing a voltage difference to a cathode and as a primary return path for electrons; a single opening arranged to communicate, in operation, with a coating chamber of the magnetron sputtering device ; an insulated outer surface arranged to electrically isolate, in operation, the vessel from chamber walls of the coating chamber ; and one or more gas inlet ports ; a conductive interior surface , adapted to be electrically coupled, in operation, to a positive output of a power supply, such that it serves, in operation, as an anode providing a voltage difference to a cathode and as a primary return path for electrons; a single opening arranged to communicate, in operation, with a coating chamber of the magnetron sputtering device ; an insulated outer surface arranged to electrically isolate, in operation, the vessel from chamber walls of the coating chamber ; and one or more gas inlet ports ; a source of sputtering gas and a source of reactive gas; wherein one of the one or more gas inlet ports is arranged, in operation, to provide a sputtering gas from the source of sputtering gas into the vessel, and the integrated anode and activated reactive gas source is arranged such that, in operation, the sputtering gas is provided through the single opening of the vessel into the coating chamber ; and wherein one of the one or more gas inlet ports is arranged, in operation, to provide a reactive gas from the source of reactive gas into the vessel, and the integrated anode and activated reactive gas source is arranged, in operation, to activate the reactive gas within the vessel and is arranged such that, in operation, the activated reactive gas is provided through the single opening of the vessel into the coating chamber . <EOS>