A semi-automatic brazing apparatus having a brazing wire feeding apparatus containing a brazing wire feed mechanism, a controller, and a user input device. More specifically, an ablation lesion is formed which electrically isolates the located source of the atrial premature contraction in the pulmonary vein from connection with the left atrium and blocks passage of the atrial premature contraction originating from the located source. These robust and non-corrosive fluorosurfactants 42, which consists of a hydrophilic chain 40 attached to a hydrophobic fluorocarbon tail 41, are applied by nebulization and replace the more complex lubricating systems, including highly reactive PFDA lubricants stored in polymer getters, to keep the parts from sticking. The amplifier has a secondary resonator that includes the gain-medium and a selectively variable attenuator, but not the optical switch. The working medium collected via the collection mechanism is stored in an open tank, and the thus-stored liquid-phase working medium is returned to a condenser by means of a return pump.