The present invention relates to a hollow cathode plasma source and to methods for surface treating or coating using such a plasma source, comprising first and second electrodes (1, 2), each electrode comprising an elongated cavity (4), wherein dimensions for at least one of the following parameters is selected so as to ensure high electron density and/or low amount of sputtering of plasma source cavity surfaces, those parameters being cavity cross section shape, cavity cross section area cavity distance (11), and outlet nozzle width (12).

The invention relates to a plasma chemical vapor deposition (PCVD) apparatus for deposition of one or more layers of silica onto an interior wall of an elongated hollow glass substrate tube. The apparatus comprises a microwave generator, a plasma generator receiving microwaves from said generator in use, a cylindrical cavity extending through said generator, and a cylindrical liner positioned in the cavity. The substrate tube passes through the liner in use. The cylindrical liner has at least one section having a reduced inner diameter over a part of the length of the liner, the at least one section providing a contact zone for the substrate tube. The microwave generator is configured to generate microwaves having a wavelength Lw in the range of 40 to 400 millimeters, wherein a length of said at least one section having the reduced inner diameter is at most 0.1?Lw.

A system is provided for generating plasma within narrow diameter tubes, e.g., tubes with an inner diameter of less than 1 millimeter. The system may comprise the tube, a nozzle connected to at least one end of the tube configured to supply a gas into the interior of the tube at atmospheric pressure, at least one ring-shaped anode electrode and configured to surround an outer surface of the tube, at least one ring-shaped cathode electrode spaced apart from the anode electrode along the longitudinal axis and configured to surround the outer surface of the tube, and a voltage source connected to the at least one anode electrode. When activated, the system is configured to generate an electric field between the electrodes which ignites a plasma within the gas in the interior of the tube.

A hollow cathode plasma polymerization process applied to fabric substrates, in particular to methods, to apply a halogen-free, in particular fluorine-free, water repellent polymer coating, in particular durable water repellent coatings, to a fabric substrate as well as the products obtainable by such methods and systems.

Embodiments herein include surface sterilization systems and methods for sterilizing packaged food items. In an embodiment, a surface sterilization system is included. The system can have a conveying mechanism configured to move discrete food packages, the food packages having opposed top and bottom surfaces, opposed right and left surfaces, and opposed front and back surfaces. The system can further include a plurality of dielectric discharge electrodes configured to come into sliding contact with the discrete food packages as they are moved by the conveying mechanism. The system can further include an electrical current source in electrical communication with the plurality of dielectric discharge electrodes, the electrical current source delivering a current to the plurality of electrodes sufficient to generate a plasma inside of the discrete food packages. Other embodiments are also included herein.

The present invention relates to a hollow cathode plasma source and to methods for surface treating or coating using such a plasma source, comprising first and second electrodes (1, 2), each electrode comprising an elongated cavity (4), wherein dimensions for at least one of the following parameters is selected so as to ensure high electron density and/or low amount of sputtering of plasma source cavity surfaces, those parameters being cavity cross section shape, cavity cross section area cavity distance (11), and outlet nozzle width (12).

A method for treating a surface of a material at atmospheric pressure comprises providing an atmospheric pressure argon plasma source capable of delivering a beam comprising a reactive gas from the source outlet, applying radio frequency (RF) power to the atmospheric pressure argon plasma source for generating the reactive gas in the beam from the source outlet, and translating the atmospheric pressure argon plasma source relative to the material at a distance from the source outlet to said surface close enough for the reactive gas from the atmospheric pressure argon plasma source to contact and treat the surface. Importantly, the beam of the reactive gas at the source outlet comprises a power density of at least 100 W/mm.

The present invention concerns a polymer substrate bearing a decorative coating comprising a protective toplayer of boron doped silicon oxide, wherein the boron doped silicon oxide comprises Si, O, B, H and OH groups and wherein the boron content is comprised between 4 and 12 atomic %. The present invention further comprises a process for depositing on a polymer substrate by linear hollow cathode type PECVD a boron doped silicon oxide layer comprising Si, O, B, H and OH groups and wherein the boron content is comprised between 4 and 12 atomic %.

A method treats a reflective optical element for the VUV wavelength range, wherein the optical element has an aluminium surface. Treating the reflective optical element comprises irradiating the reflective optical element with a hydrogen plasma jet for removing an aluminium oxide layer formed on the aluminium surface. A reflective optical element for use in the VUV wavelength range treated by the method can be included in an optical arrangement.

A system is provided for generating plasma within narrow diameter tubes, e.g., tubes with an inner diameter of less than 1 millimeter. The system may comprise the tube, a nozzle connected to at least one end of the tube configured to supply a gas into the interior of the tube at atmospheric pressure, at least one ring-shaped anode electrode and configured to surround an outer surface of the tube, at least one ring-shaped cathode electrode spaced apart from the anode electrode along the longitudinal axis and configured to surround the outer surface of the tube, and a voltage source connected to the at least one anode electrode. When activated, the system is configured to generate an electric field between the electrodes which ignites a plasma within the gas in the interior of the tube.