Equivalent circuit analysis of rf discharge plasma and its period doubling behavior due to nonlinear capacitance

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:226868

Chung, T H; Yoon, H J ^[1]; Lee, J K ^[2]

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1. Dong-A Univ., Pusan (Korea, Democratic People`s Republic of)
2. POSTECH, Pohang (Korea, Democratic People`s Republic of)

It has been known that a driven nonlinear RLC circuit can exhibit period doubling (PD) and chaos. The nonlinear element in the circuit is a varacter diode whose capacitance varies as a function of the voltage across it. Capacitively coupled RF Discharge system also displayed a similar characteristic of the nonlinear RLC circuit. In this work, we present computational results obtained using spherical many-particle simulation models. The simulation codes is PDS1 (plasma device spherical one-dimensional) which utilize PIC technique plus Monte Carlo method for the charged particle-neutral collisions. Simulation can reinforce experiment by investigating new parameter regimes and physics associated with new regime outside those seen in the laboratory. When an electrical system with nonlinear impedance characteristics operates periodically with frequency f, higher harmonics will be generated by the nonlinearity at frequencies 2f, 3f, 4f, etc, and subharmonics will also be generated at frequencies f/2, 3f/2, 5f/2, etc. Above a certain power level of the driver, the subharmonics which is indicative of a period-doubling(PD) bifurcation becomes dominant. We plot the PD thresholds for varying pd(where p is the neutral gas pressure, and d is the gap distance). Period doubling bifurcations manifest themselves in driven system by an alternation of state variables between different values on successive cycles of the excitation waveforms. This corresponds to the generation of subharmonics(f/2) and odd-multiples of the half-harmonic frequency.

• OSTI ID: 226868
• Report Number(s): CONF-950749--
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
66 PHYSICS
BREAKDOWN
CAPACITANCE
EQUIVALENT CIRCUITS
HIGH-FREQUENCY DISCHARGES
IMPEDANCE