摘要
An instability in the stable operation of microdischarges sustained at microwave frequencies,is investigated by a self-consistent one-dimensional particle-in-cell Monte Carlo collisions model.The instability is caused by the field electron emission from electrodes and is triggered by the high electric fields at the sheaths in a dense microplasma.For an operating frequency of 9 GHz,and electrode gap of 60μm,the field emission(FE)is not active at the breakdown voltage.However,once a stable dense plasma is produced post-breakdown,a strong sheath results in an electrode electric fields that exceed the threshold for FE causing a runaway in the electron generation in the plasma.
基金
the Air Force Office of Scientific Research(AFOSR)through a Multi-University Research Initiative(MURI)grant titled‘Plasma-Based Reconfigurable Photonic Crystals and Metamaterials’with Dr.Mitat Birkan as the program manager.
