ABSTRACT
This chapter considers the complementary phenomena of overtones and partial signals that are present in technological low-pressure and atmospheric-pressure plasma jets. The physical origin of these plasma harmonic arises from the rapid oscillatory momentum of electrons and ions within the imposed electric field of the plasma ion sheaths that separates the plasma bulk from the reactor walls. The chapter provides an insight into the interaction of electrically generated harmonics and sound-pressure generated acoustic overtones that have been recently presented for linear-field atmospheric-pressure plasma jet that is electrically driven in the kilohertz frequency range. An alternative electromagnetic theory to the transmission-line model would be that second-order mixing is responsible for the harmonic dropout. Historically, the counting of the overtone number differs from the harmonic number as the first overtone is considered to be twice the frequency of the fundamental or one octave higher.
