The present disclosure is directed to an electrosurgical apparatus for generating plasma in electrosurgical applications. The electrosurgical apparatus includes an end effector disposed on a distal portion of a tube of the electrosurgical apparatus. The end effector mixes ambient air with an inert gas to increase the production of radical species. In one aspect of the present disclosure, the end effector includes a cylindrical augmenter disposed over a distal end of the tube with one or more tilted vanes disposed between the cylindrical augmenter and the tube. In another aspect of the present disclosure, the end effector includes one or more tilted vanes disposed on an inner surface of a wall of the distal end of the tube. In another aspect of the present disclosure, the end effector includes one or more advection apertures on the wall of the distal end of the tube.