Nanosecond breakdown in a pulsed open discharge

The paper presents the results of studies of open discharge breakdown characteristics at nanosecond supply pulse in helium, neon, argon working medium in a wide pressure range. It is shown that the open discharge exists in the range of p He = 20–100 Torr, pNe = 1.5–25 Torr, p Ar = 0.5–3.7 Torr with used experimental conditions. With increasing pressure, the role of separate elementary processes increases which can lead to a change of the discharge form to a presumably avalanche or streamer discharge. However, in this case, due to the photoemissive nature of the open discharge initiation, the similarity law Ep = f(pι) does not coincide with that for a nanosecond avalanche discharge.

Коммутация высоковольтных импульсов в устройствах на основе открытого разряда в азоте и кислороде

Comparative studies of the switching characteristics of devices based on an open discharge - kivotrons in molecular gases (nitrogen and oxygen), as well as their mixtures with helium - have been carried out. The choice of nitrogen and oxygen is due to the fact that the emission coefficients of electrons under the action of their heavy particles are much higher than for helium. It is shown that for this case, as well as with the predominance of the photoelectronic emission mechanism in helium, it is also possible to create fast switches. Their advantage is significantly lower requirements for the cleanliness of the working environment.

Heat flow from the Earth interior as indicator of deep processes

The energy aspects of the problem of intraterrestrial heat transfer in various forms are discussed. Endogenous causes of conductive heat flow dispersion − radiogenic heat generation, tectonic movements and magmatism (volcanism), including its latent and open discharge in the form of volcanic and hydrothermal activity are considered. The geological ordering of the heat flow in the continental crust is related to convective discharge of the heat and mass flux from the mantle, marked by the isotopic composition of helium in freely circulating underground fluids. The combined transport of heat and helium, as well as the correlation of He isotopic compositions in volcanic and hydrothermal gases and Sr compositions in young lavas, testify to the silicate nature of the heat and mass flow emanating from the mantle reservoirs of different depths.