Abstract Streamer discharges occur in the early stages of electric breakdown gases lightning, as well plasma and high voltage technology. They are growing filaments characterized by a curved charge layer at their tip that enhances field ahead them. In this study, we analyze effect strong electron attachment on propagation positive streamers. Strong occurs insulating like sulphur hexafluoride (S...

The performance of differential IMS (FAIMS) analyzers is much enhanced by gases comprising He, especially He/N2 mixtures. However, electrical breakdown has limited the He fraction to ~50%-75%, depending on the field strength. By the Paschen law, the threshold field for breakdown increases at shorter distances. This allows FAIMS using chips with microscopic channels to utilize much stronger fiel...

Recent work shows that the range of morphology of anode streamers in liquid dielectric breakdown is predicted when it is represented as stochastic growth of a branching fractal tree. This model may be analogous to the critical volume model of breakdown used in gases. Assuming there is a relationship, leads to a concept of how affecting the electron production and recombination rates in a fluid ...

Concerns about atmospheric emissions of greenhouse gases and operation costs are converging to increase incentives for both the electric utility and magnesium industries to rapidly locate and repair equipment leaks (Irwin, 1997). The primary culprit is sulfur hexafluoride (SF6), an invisible, non-hazardous, inert gas with near-perfect dielectric properties that is used as an insulating gas in h...

In order to understand the performance of photonic bandgap (PBG) structures under realistic high gradient, high power, high repetition rate operation, a PBG accelerator structure was designed and tested at X-Band (11.424 GHz). The structure consisted of a single test cell with matching cells before and after the structure. The design followed principles previously established in testing a serie...

When a swarm of positrons is introduced into a gaseous assembly, there are many processes by which the positrons can arrive at their eventual annihilation fate. Depending on the energy, some positrons form positronium prior to annihilation. However, when the energy is less than the positronium formation threshold, Eth (9 eV for argon, 17.8 eV for helium, etc.), then only elastic collisions are ...

Ion thrusters are being designed for long-term operation at power, specific impulse, and thrust levels of up to 29 kW, 7000 seconds, and 0.64 N, respectively. The total propellant throughput goal of these thrusters is nearly 100 kg/kW, which corresponds to ~100 khr of operation. Carbon-based grids have been chosen as the baseline design to achieve this propellant throughput and life time goal. ...