Patent ID: 7967945

Claim:
An antenna assembly for treatment of an inner surface of a tube with the use of inductively coupled plasma and by means of a chemical plasma reaction comprising: a first supporting element which has outer dimensions slidingly fitted into the tube to be treated; a second supporting element spaced from the first supporting element and having outer dimensions slidingly fitted into the tube to be treated; a spacer between the first supporting element and the second supporting element that rigidly interconnects the first and second supporting elements and has outer dimensions smaller than the outer dimensions of the first and second supporting elements for forming a gap with the tube when the antenna assembly is inserted into the tube, the spacer being made from a material penetrable to RF energy; a transversal RF antenna unit supported by the first supporting element and inserted into the spacer, the antenna unit having means for generating a transversal magnetic field penetrable through the spacer into the gap between the spacer and the tube when the antenna assembly is inserted into the tube for treatment of the inner surface of the tube; an RF generator unit connected to the transversal antenna unit for supply of RF energy to the transversal antenna unit; means for supply of a precursor gas into the gap through the first supporting element; and means for evacuation of products of the plasma reaction through the second supporting element.