Breakdown, stability and similarity laws of microplasmas

• Applicant: Dr. Ilija Stefanovic
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: from 2009 to 2016
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 74729252

The discharge instabilities in microplasmas could lead to a chaotic behavior of the current and voltage. To understand the basic properties of microdischarges that govern the discharge stability it is necessary to analyze the discharge transient behavior between defined discharge modes, starting from low-current, Townsend-like discharge to the high-current abnormal glow discharge. In particular, the influence of electric circuitry and conditions of wall and electrode surfaces on the discharge stability will be studied. By measuring spectrally resolved or integrated optical emission and absorption, the different discharge regions will be characterized in order to find out how the different volume and surface processes influence the discharge stability. The large metastable densities in microdischarges can influence the gas and surface reactions (secondary emission). The dynamics of metastables is especially important as due to jd2 scaling the current densities may be quite high in microdischarges, even in the Townsend low current regime. To discriminate between different secondary processes on the electrodes we need to separate photon, ion and metastable processes, which should appear on different time scales. The laser assisted discharge breakdown provided by A2 should enable this discrimination.

• DFG Programme: Research Units
• Subproject of: FOR 1123: Physics of Microplasmas