This work deals with the experimental study of a surface dielectric-barrier discharge,as a part of the ongoing interest in the control of plasma induced electro-fluid dynamic effects(e.g.plasma actuators).The discharg...This work deals with the experimental study of a surface dielectric-barrier discharge,as a part of the ongoing interest in the control of plasma induced electro-fluid dynamic effects(e.g.plasma actuators).The discharge is generated using a plasma reactor consisting of a fused silica plate which is sandwiched between two printed circuit boards where the electrodes are developed.The reactor is driven by narrow high voltage square pulses of asymmetric rising(25 ns)and falling(2.5μs)parts,while the discharge evolution is considered in a temporarily and spatially resolved manner over these pulses.That is,conventional electrical and optical emission analyzes are combined with high resolution optical emission spectroscopy and ns-resolved imaging,unveiling main characteristics of the discharge with a special focus on its propagation along the dielectric-barrier surface.The voltage rising part leads to cathode-directed ionization waves,which propagate with a speed up to 105m s~(-1).The voltage falling part leads to cathode sheath formation on the driven electrode.Τhe polarization of the dielectric barrier appears critical for the discharge dynamics.展开更多
Optical emission spectroscopy parallel to the axis of a low-pressure radio-frequency discharge in nitrogen was realized, i. e. end-on instead of customary side-on measurements. A specially designed optical feedthrough...Optical emission spectroscopy parallel to the axis of a low-pressure radio-frequency discharge in nitrogen was realized, i. e. end-on instead of customary side-on measurements. A specially designed optical feedthrough was fabricated and installed co-planar with the anode elec- trode, allowing non-invasive observations perpendicular to the plasma sheath. The principal ex- cited species flowing towards the grounded electrode were identified and, by assuming Boltzmann distributions, the vibrational temperature of the molecules on the X1 ∑＋/g and C3Ⅱu levels was estimated under various operating conditions.展开更多
文摘This work deals with the experimental study of a surface dielectric-barrier discharge,as a part of the ongoing interest in the control of plasma induced electro-fluid dynamic effects(e.g.plasma actuators).The discharge is generated using a plasma reactor consisting of a fused silica plate which is sandwiched between two printed circuit boards where the electrodes are developed.The reactor is driven by narrow high voltage square pulses of asymmetric rising(25 ns)and falling(2.5μs)parts,while the discharge evolution is considered in a temporarily and spatially resolved manner over these pulses.That is,conventional electrical and optical emission analyzes are combined with high resolution optical emission spectroscopy and ns-resolved imaging,unveiling main characteristics of the discharge with a special focus on its propagation along the dielectric-barrier surface.The voltage rising part leads to cathode-directed ionization waves,which propagate with a speed up to 105m s~(-1).The voltage falling part leads to cathode sheath formation on the driven electrode.Τhe polarization of the dielectric barrier appears critical for the discharge dynamics.
文摘Optical emission spectroscopy parallel to the axis of a low-pressure radio-frequency discharge in nitrogen was realized, i. e. end-on instead of customary side-on measurements. A specially designed optical feedthrough was fabricated and installed co-planar with the anode elec- trode, allowing non-invasive observations perpendicular to the plasma sheath. The principal ex- cited species flowing towards the grounded electrode were identified and, by assuming Boltzmann distributions, the vibrational temperature of the molecules on the X1 ∑＋/g and C3Ⅱu levels was estimated under various operating conditions.
