A plasma instrument includes an elongated body defining a lumen therethrough, the lumen being in fluid communication with an ionizable media source; and a plasma applicator coupled to a distal portion of the elongated body. The plasma applicator includes: an active electrode configured to couple to an active terminal of a generator; and a corona electrode configured to couple to a return terminal of a generator. The plasma instrument also includes a switching element coupled to the corona electrode, the switching element configured to control at least one of resistivity or connectivity of the corona electrode to a generator.