scholarly journals Влияние вида функции распределения электронов в плазме и дисперсии по энергии электронного пучка на устойчивость низковольтного пучкового разряда

2021 ◽  
Vol 91 (4) ◽  
pp. 579
Author(s):  
В.С. Сухомлинов ◽  
P.М. Матвеев ◽  
А.С. Мустафаев ◽  
В.А. Павлов ◽  
С.В. Гордеев
Keyword(s):  
Electron Beam ◽  
Electron Energy ◽  
Low Voltage ◽  
Mean Free Path ◽  
Inert Gases ◽  
Loss Of Stability ◽  
Average Electron Energy ◽  
Cathode Temperature ◽  
Average Electron ◽  
Electron Mean Free Path

Within the framework of the kinetic approach, the conditions for the loss of stability of a low-voltage beam discharge in inert gases (LVBD) are studied depending on the temperature of the electron beam, the dispersion of the electron beam velocity in the direction of the discharge axis, and the form of the electron energy distribution function (EEDF). Regimes are considered when the interelectrode distance is on the order of the electron mean free path relative to elastic collisions with inert gas atoms. It is shown that the beam temperature Tb, determined in the LVBD by the cathode temperature not exceeding 1500 K, and the dispersion of the beam electron energy, which in the LVBD can be significantly higher than kTb and reaches 1 - 2 eV, have little effect on the conditions for the loss of stability of the LVBD and the magnitude of the growth rate of disturbance amplification at frequencies up to plasma It was found that the form of the EEDF monotonically decreasing with increasing electron energy also does not affect the parameters of the perturbations propagating in the LVBD at the beam energy much higher than the average electron energy in the plasma. The results obtained are applicable not only to LVBD, but also to other types of self-sustained beam discharges.

Measurements of Electron Energy by Emission Spectroscopy in Pulsed Corona and Dielectric Barrier Discharges

2003 ◽  
Vol 6 (1) ◽  
Author(s):  
Yongho Kim ◽  
Sang Hee Hong ◽  
Min Suk Cha ◽  
Young-Hoon Song ◽  
Seock Joon Kim
Keyword(s):  
Electron Energy ◽  
Spectroscopic Method ◽  
Optical Emission ◽  
Dielectric Barrier Discharges ◽  
Time Resolved ◽  
Average Electron Energy ◽  
Dielectric Barrier ◽  
Pulsed Corona ◽  
Average Electron ◽  
Barrier Discharges

AbstractElectric field distributions and average electron energies are measured by an optical emission spectroscopic method to investigate streamer characteristics in a pulsed corona discharge (PCD) and a dielectric barrier discharge (DBD) in atmospheric air. In PCD, average electron energies appear to be in the range of 10 ~ 12 eV along the streamers. Time-resolved measurements show that streamers in DBD have a relatively low value of average electron energy of 9 ~ 10 eV. Enhancement of the electron energy is observed when DBD is operated in a non-uniform geometry, such as dielectric barrier with a hole.

scholarly journals The Influence of Humidity on Electron Transport Parameters and Insulation Performance of Air

2022 ◽  
Vol 9 ◽  
Author(s):  
Yunzhu An ◽  
Menghan Su ◽  
Yuanchao Hu ◽  
Shangmao Hu ◽  
Tao Huang ◽  
...  
Keyword(s):  
Electron Transport ◽  
Relative Humidity ◽  
Electron Energy ◽  
Transport Parameters ◽  
Average Electron Energy ◽  
Electron Diffusion Coefficient ◽  
External Insulation ◽  
Calculation Results ◽  
Average Electron ◽  
Insulation Performance

The environmental conditions affect the external insulation performance of power equipment. In order to study the physical characteristics of air discharge, the microscopic process of electron–molecule collision in the air based on the Boltzmann equation has been studied in this paper. The influence of humidity on the air gap insulation performance was also analyzed. The calculation results show that with the temperature 300 K and the pressure 1.0 atm, the electron energy distribution function and electron transport parameters varied with the air relative humidity. As the air relative humidity is increased by each 30%, the average electron energy decreases by about 0.2 eV, the reduced electron mobility decreases by about 0.25 × 1023 [1/(V·m·s)], the reduced electron diffusion coefficient decreases by about 0.2 × 1024 [1/(m s)], and the effective ionization coefficient decreases by about 4 × 10−24 m2. As the air relative humidity increases from 0% to 60%, the critical breakdown electric field increases by 1.22 kV/cm.

scholarly journals Структура призондового слоя в газоразрядной плазме при произвольной ориентации плоского зонда относительно электрического поля в плазме

2019 ◽  
Vol 89 (10) ◽  
pp. 1545
Author(s):  
O. Мурильо ◽  
А.С. Мустафаев ◽  
В.С. Сухомлинов
Keyword(s):  
Electric Field ◽  
Electron Energy ◽  
Exchange Process ◽  
Mean Free Path ◽  
Ionization Rate ◽  
Inert Gases ◽  
Mutual Orientation ◽  
Mean Velocity ◽  
Charge Exchange Process ◽  
The Mean

AbstractWe investigate the structure of the wall sheath of a gas discharge near a flat surface at a negative potential for high mean electron energy. It is shown that in the conditions where the mean energy of ions in the plasma is much lower than the mean electron energy, the parameters of the wall sheath weakly depend on the mutual orientation of the normal to the surface and the electric field in the plasma for an arbitrary ratio of the Debye radius to the ion mean free path relative to the resonant charge exchange process. It is found that for inert gases (He, Ar) for ratio E / P of the electric field to pressure exceeding 10 V/(cm Torr) in the plasma, the disregard of ionization in the perturbed wall sheath can lead to substantial errors in the calculation of its parameters. It is shown that the ionization leads to an increase in the electric field in the wall sheath and, as a consequence, to an increase in the mean velocity of ions at the boundary between the quasi-neutral presheath and the part of the perturbed wall sheath in which quasi-neutrality is substantially violated. The parameters of the wall sheath where quasi-neutrality is significantly violated depend on the ionization rate much less strongly than the corresponding parameters of the quasi-neutral presheath. We have determined the relation for concentration of charged particles in the unperturbed plasma from the ion saturation current considering the actual ion energy distribution function in the plasma as well as ionization in the presheath and the part of the perturbed wall sheath in which quasi-neutrality is violated significantly.

Energy relaxation for thermal electrons in CO

1968 ◽  
Vol 46 (11) ◽  
pp. 1323-1330 ◽  
Author(s):  
Michael H. Mentzoni ◽  
James Donohoe
Keyword(s):  
Electron Energy ◽  
Cross Sections ◽  
Loss Rate ◽  
Dipole Interaction ◽  
Energy Relaxation ◽  
Average Electron Energy ◽  
Cross Modulation ◽  
Energy Relaxation Time ◽  
Average Electron ◽  
Electron Energy Loss

Using published cross sections for rotational excitation and de-excitation caused by dipole and quadruple interactions in carbon monoxide, the average electron energy loss rate, [Formula: see text], is computed as a function of excess electron temperature, Te − T, for the case of a maxwellian velocity distribution for various gas temperatures, T. It is found that the dipole and quadrupole contributions to the loss rate are in the ratio 3:1 with the composite electron energy relaxation time given by pτ = 338 ns Torr for Tgas = 300 °K. The initial values of [Formula: see text] caused by dipole interaction decrease more rapidly with temperature than T−1/2, which was the temperature variation found in the case of quadrupole interaction. Experimentally, microwave cross-modulation results pertaining to the isothermal afterglow of a d-c. discharge in CO yielded the value pτ = 113 ± 11 ns Torr for T = 300 °K. The apparent discrepancy between theory and experiment is discussed.

scholarly journals A substorm in midnight auroral precipitation

2003 ◽  
Vol 21 (12) ◽  
pp. 2271-2280 ◽  
Author(s):  
V. G. Vorobjev ◽  
O. I. Yagodkina ◽  
G. V. Starkov ◽  
Ya. I. Feldstein
Keyword(s):  
Solar Wind ◽  
Electron Energy ◽  
Energy Flux ◽  
Dynamic Pressure ◽  
Auroral Zone ◽  
Substorm Onset ◽  
Electron Precipitation ◽  
Average Electron Energy ◽  
Central Plasma ◽  
Average Electron

Abstract. DMSP F7 spacecraft observations for the whole of 1986 were used to construct the empirical model of the midnight auroral precipitation during a substorm. The model includes the dynamics of different auroral precipitation boundaries and simultaneous changes in average electron precipitation energy and energy flux in different precipitation regions during all substorm phases, as well as the IMF and solar wind plasma signatures during a substorm. The analysis of the model shows a few important features of precipitation. (1) During the magnetic quietness and just before the beginning of the substorm expansive phase the latitudinal width of the auroral precipitation in the nightside sector is about 5 – 6° CGL, while that of the auroral oval is about 2 – 3° CGL during such periods. (2) For about 5 min before the substorm onset a decrease in the average precipitating electron energy in the equatorward part of auroral zone was observed simultaneously, with an increase in both the average electron energy and energy flux of electron precipitation in the poleward part of the auroral zone. (3) The isotropy boundary position in the beginning of the substorm expansive phase coincides well with the inner edge of the central plasma sheet. The analysis of interplanetary medium parameters shows that, on average, during the substorm development, the solar wind dynamic pressure was about 1.5 times that of the magnetic quietness period. Substorms occurred predominantly during the southward IMF orientation, suggesting that substorm onset often was not associated with the northern turn or decrease in the southward interplanetary Bz . The Northern Hemisphere’s substorms occurred generally during the positive interplanetary By in winter, and they were observed when the interplanetary By was negative in summer.Key words. Ionosphere (auroral ionosphere; particle precipitation) – Magnetospheric physics (storm and substorm; magnetosphere-ionosphere interaction)

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