A sputtering magnetron (300) insertable in a rotatable target is described. The magnetron is designed around a single piece, multiwalled tube (102, 202) with compartments (316, 316′, 318, 318′) extending over the length of the tube. The multiwalled tube gives a much stiffer magnetron carrier structure compared to prior art magnetrons. As a result, the magnetic field generator can be mounted inside a compartment and the distance between magnets and target surface is easily adjustable as the tube is much stiffer than the generator. Additionally, the coolant channels can be incorporated inside the tube and close to the outer wall of the tube so that coolant can be supplied in the vicinity of the magnetic field generator. The increased stiffness of the magnetron allows the target tube to be carried by the magnetron—not the other way around—at least during part of the useful life of the target. As a result thin target carrier tubes can be used as they don't have to carry the magnetron anymore resulting in a longer use of the target.