The device comprises an outer conductor (7) and an inner conductor (9) arranged approximately coaxial with each other. The outer conductor surrounds the inner conductor. The outer conductor (7) and the inner conductor (9) are arranged and configured to generate an electromagnetic field with lines of force extending from a front surface (9A) of the inner conductor (9) to a front surface (7C) of the outer conductor (7). The device further comprises an energy delivery window (13) arranged in front of the outer conductor and the inner conductor.
