Method of and apparatus for treating or coating a surface

A method of treating or coating a surface, the method comprising the steps of:

• creating a plasma jet by discharging electricity between two electrodes in the presence of a process gas;
• feeding the plasma jet in a predetermined jet direction into a generally closed reaction chamber;
• preventing oxygen-containing ambient air from entering the chamber while feeding a carrier gas into the chamber through an inlet port in a direction transverse to the jet direction;
• swirling together and thoroughly mixing the plasma jet with the carrier gas in the chamber to activate the carrier gas or form a particle beam;
• flowing the carrier gas or particle beam out of the chamber through an outlet port in a direction transverse to the jet direction while confining the plasma jet in the chamber;
• and
• impinging the carrier gas or particle beam outside the chamber on the surface to be treated or coated.

An apparatus for treating or coating a surface, the apparatus comprising:

• a closed reaction chamber having a plasma-jet inlet port, a separate carrier-gas inlet port, and an outlet port, the carrier-gas inlet port and the outlet port opening into the chamber toward each other along a common axis of the chamber, the plasma-jet inlet port opening into the chamber transversely of the axis, the chamber being closed across from the plasma-jet inlet port;
• a generator having two electrodes and a supply of process gas for forming a plasma jet and feeding it through the plasma-jet inlet port into the chamber transversely of the axis;
• and
• means for
• feeding a carrier gas into the chamber through the carrier-gas inlet port parallel to the axis and thereby swirling together and thoroughly mixing the plasma jet with the carrier gas to activate the carrier gas or form a particle beam,
• flowing the carrier gas or particle beam out of the chamber through the outlet port in a direction parallel to the axis while confining the plasma jet in the chamber, and
• impinging the carrier gas or particle beam outside the chamber on the surface to be treated or coated.