Certain embodiments described herein are directed to generators that can be used to sustain a plasma. In some embodiments, the generator comprises an oscillation circuit configured to electrically couple to an induction device and provide power to the induction device in an oscillation mode to sustain the inductively coupled plasma in a torch body, the circuit configured to provide harmonic emission control during sustaining of the inductively coupled plasma in the torch body in the oscillation mode of the generator.