The invention relates to an arrangement for transporting radicals. The arrangement includes a plasma generator and a guiding body. The plasma generator includes a chamber (2) in which a plasma may be formed. The chamber has an inlet (5) for receiving an input gas, and one or more outlets (6) for removal of at least one of the plasma and radicals created therein. The guiding body is hollow and is arranged for guiding radicals formed in the plasma towards an area or volume at which contaminant deposition is to be removed. The chamber inlet is coupled to a pressure device (40) for providing a pulsed pressure into the chamber so as to create a flow in the guiding body.