Rajib Mahamud

Suppression of self-pulsing regime of direct current driven microplasma discharges

An instability suppressor circuit for self-pulsing direct current (DC) driven microplasma discharge is proposed and experimentally tested over a range of pd values for helium feed gas. The external circuit configuration suppresses self-pulsing of the discharge, extending the normal glow regime to lower currents. The negative differential resistance (NDR) region was observed to shift further left in the voltage–current parametric space (i.e., lower current), and the slope of the NDR region was decreased substantially. In addition, the suppressor element decreased the pulsing frequency as well as the static positive resistance of the discharge in the shifted NDR region. Modeling of the discharge configuration indicated that the inductor element of the suppressor circuit increases the time lag of the plasma response, which increases the stable region of operation. A stability map in terms of the external circuit parameters is introduced.