Abstract: In a method for treatment of a dispersed material in a plasma, in which a plasma-forming gas is introduced into a reaction chamber and ionized and a dispersed material is introduced into the reaction chamber and into the area of the plasma, treated under the action of the plasma, and subsequently removed from the area of the plasma, the introduction of the plasma-forming gas and the introduction of the dispersed material are performed independently of one another and from different directions. In an apparatus for treatment of a dispersed material in a plasma, which comprises a reaction chamber having a plasma generator, a first inlet for a plasma-forming gas, and a second inlet for the dispersed material, the second inlet is situated spatially separated in relation to the first inlet so that the dispersed material is conducted from the outside into the plasma.

Abstract: A method and apparatus for making an optical fiber preform, including injecting a plasma gas source into the first end of a tubular member; generating a ring plasma flame with the plasma gas source flowing through a plasma gas feeder nozzle, the plasma gas feeder nozzle including: an inner tube, an outer tube, wherein the plasma gas source is injected between the inner tube and the outer tube to produce the ring plasma flame, such that at least a portion of the ring plasma flame is directed radially toward the inner surface of the tubular member; traversing the tubular member along the longitudinal axis relative to the plasma flame; depositing at least one soot layer on the interior surface of the tubular member by introducing reagent chemicals into the plasma flame; and fusing all of the soot layers into a glass material on the interior surface of the tubular member.

Abstract: The improved plasma torch for making synthetic silica includes use of nitrogen screen gas from outer quartz tubing to provide active environment isolation. In addition, the present induction plasma torch includes a ring disk for more compact but complete environmental protection (360 degree coverage). It also includes offsetting and switching the position of the chemical injection nozzles for allowing improved deposition in both directions, when operated in a horizontal mode. Further, the present induction plasma torch maintains laminar flow for the injected chemicals and the middle quartz tube is provided with a concave section for increasing the average enthalpy of plasma jet, thus improving the efficiency of the plasma torch. In addition, it may utilize more plasma gas inlets. It also includes chemical injection nozzles having a downward angular inclination.