[1] This paper presents an overview of the recent modeling efforts directed to the interpretation of observed features of transient luminous events termed sprites, blue jets, and gigantic jets. The primary emphasis is placed on interpretation of various emissions documented to date from sprites and comparison of exiting models with recent high‐speed video and satellite‐based observations of spr...

In this thesis I investigate the possibility of electrically detecting partial discharges in high voltage equipment. Partial discharges are small events that occur in insulation in the presence of high electric field intensity and manifest themselves as pulses of current superimposed on the high voltage lines. They carry important information about the condition and operation of such equipment....

A critical analysis of photoionization as the major process for seed electron production ahead of the cathode-directed streamer has been made. The accumulation of O2 ions between pulses and fast electron detachment in an electric field could be an effective source of seed electrons for repetitively pulsed discharges in electronegative gases. Measurements and two-dimensional calculations in the ...

This Letter reports a modeling study on the formation of streamer discharges from an isolated ionization column under subbreakdown condition. Numerical simulations show that positive streamers are able to form from the tip of an ionization column in a uniform applied electric field well below the breakdown threshold field. However, even when the applied field approaches the breakdown threshold ...

The electric field in streamer discharges in air can be easily determined by the ratio of luminous intensities emitted by N2(C 3 u) and N2(B 2 + u ) if the steady-state assumption of the emitting states is fully justified. At ground pressure, the steady-state condition is not fulfilled and it is demonstrated that its direct use to determine the local and instantaneous peak electric field in the...

[1] In this study, we identify and examine electric field pulse trains that are characteristic of preliminary breakdown in negative cloud-to-ground discharges but are not followed by return stroke waveforms. We assume that such trains are manifestations of the initiation of downward negative stepped leaders that fail to propagate all the way to the ground and refer to these events as ‘‘attempte...

Discharges in hydrogen, ignited by wire explosion, with current amplitude up to 1.5 MA were investigated. Channel diameter oscillations were observed on the photostreaks. Voltage and current curves correlated with the photostreaks. At initial gas pressure of 5-35 MPa the oscillation period was proportional to square root of atomic number of the initiating wire material. These oscillations were ...

Multi-atmospheric pressure, pulsed electric discharge excited lasers require pre-ionization to produce spatially uniform glows. Many such systems use corona bars to produce ultraviolet (UV) and vacuum ultraviolet (VUV) light as photo-ionization sources for this purpose. Corona bars are transient surface discharges, typically in a cylindrical geometry, that sustain high electron temperatures and...

Life defined as a chemical system capable of transferring its molecular information via self-reproduction and of evolving probably originated from the reaction of reduced carbon-based organic matter on the primitive Earth. Primitive carbon was available as gaseous compounds, either oxidized (carbon dioxide, carbon monoxide) or reduced (methane). More complex organic molecules might have been fo...