On Refining the Criterion for a Single Avalanche-tо-Streamer Transition in Air in Strong Uniform Electric Fields

Vestnik MEI ◽  
2020 ◽  
Vol 6 (6) ◽  
pp. 29-38
Author(s):  
Andrey A. Beloglovsky ◽  
Keyword(s):  
Electric Fields ◽  
Impact Ionization ◽  
Plasma Channel ◽  
Atmospheric Conditions ◽  
Streamer Channel ◽  
The Moment ◽  
Discharge Gap ◽  
Effective Ionization ◽  
Plasma Streamer ◽  
Air Discharge

The article presents the results from mathematical modeling of avalanche-to-streamer transitions in an air discharge gap. The electric field is uniform with the strength E0=50--70 kV/cm, and the atmospheric conditions are standard. The consideration is limited to single avalanche-to-streamer (SATS) transitions. The moment of time corresponding to the plasma streamer channel incipience is taken as the transition moment. As a result of the SATS transition, a two-headed streamer is generated. First, its negative anode-directed head is formed from the avalanche. After that, its positive cathode-directed head emerges from the avalanche track. Behind it, the field strength decreases to a critical value at which effective impact ionization is impossible. The streamer plasma channel occurs earlier, in the negative head incipience process. When it appears, effective ionization still continues between the avalanche and its track. The critical number of electrons in the avalanche, which is determined by the time the channel appears, depends weakly on the E0 value if the avalanche-streamer transition occurs far from the electrodes. In this case, it is about 30 million. If the transition occurs near the electrodes, this number lies in the range from 40 to 50 million particles.

Dendritic Growth Failure of a Mesa Diode

1997 ◽  
Author(s):  
P. Singh ◽  
V. Cozzolino ◽  
G. Galyon ◽  
R. Logan ◽  
K. Troccia ◽  
...  
Keyword(s):  
Electric Fields ◽  
Dendritic Growth ◽  
Silicon Oxide ◽  
Impact Ionization ◽  
Electron Tunneling ◽  
Growth Failure ◽  
Side Wall ◽  
Oxide Interface ◽  
Band Bending ◽  
Cross Section Area

Abstract The time delayed failure of a mesa diode is explained on the basis of dendritic growth on the oxide passivated diode side walls. Lead dendrites nucleated at the p+ side Pb-Sn solder metallization and grew towards the n side metallization. The infinitesimal cross section area of the dendrites was not sufficient to allow them to directly affect the electrical behavior of the high voltage power diodes. However, the electric fields associated with the dendrites caused sharp band bending near the silicon-oxide interface leading to electron tunneling across the band gap at velocities high enough to cause impact ionization and ultimately the avalanche breakdown of the diode. Damage was confined to a narrow path on the diode side wall because of the limited influence of the electric field associated with the dendrite. The paper presents experimental details that led to the discovery of the dendrites. The observed failures are explained in the context of classical semiconductor physics and electrochemistry.

Impact ionization in AIIIBV semiconductors in high electric fields

1987 ◽  
Vol 140 (1) ◽  
pp. 9-37 ◽  
Author(s):  
A. P. Dmitriev ◽  
M. P. Mikhailova ◽  
I. N. Yassievich
Keyword(s):  
Electric Fields ◽  
Impact Ionization ◽  
High Electric Fields

scholarly journals Experimental investigation of ion beam transport in laser initiated plasma channels

2002 ◽  
Vol 20 (4) ◽  
pp. 559-563 ◽  
Author(s):  
D. PENACHE ◽  
C. NIEMANN ◽  
A. TAUSCHWITZ ◽  
R. KNOBLOCH ◽  
S. NEFF ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Heavy Ions ◽  
Plasma Channel ◽  
Ion Beam ◽  
Heavy Ion ◽  
High Current ◽  
Beam Transport ◽  
Electrode Gap ◽  
Discharge Gap ◽  
The Magnetic Field

The aim of the presented experiments is to study the transport of a heavy ion beam in a high-current plasma channel. The discharge is initiated in NH3 gas at pressures between 2 and 20 mbar by a line-tuned CO2 laser. A stable discharge over the entire electrode gap (0.5 m) was achieved for currents up to 60 kA. Concerning the ion beam transport, the magnetic field distribution inside the plasma channel has to be known. The ion-optical properties of the plasma channel have been investigated using different species of heavy ions (C, Ni, Au, U) with 11.4 MeV/u during six runs at the Gesellschaft für Schwerionenforschungs-UNILAC linear accelerator. The high magnetic field allowed the accomplishment of one complete betatron oscillation along the discharge channel. The results obtained up to now are very promising and suggest that, by scaling the discharge gap to longer distances, the beam transport over several meters is possible with negligible losses.

scholarly journals Ionization Waves Enhance the Production of X-rays during Streamer Collisions

Atmosphere ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1101
Author(s):  
Vernon Cooray ◽  
Gerald Cooray ◽  
Marcos Rubinstein ◽  
Farhad Rachidi
Keyword(s):  
Experimental Data ◽  
Electric Field ◽  
Electric Fields ◽  
Time Synchronization ◽  
Field Enhancement ◽  
Opposite Polarity ◽  
X Rays ◽  
Weakly Conducting ◽  
Ionization Waves ◽  
Discharge Gap

Experimental data show that in laboratory sparks, X-rays are produced in time synchronization with the meeting of streamers of opposite polarity just before the final breakdown of the discharge gap. It has been suggested that the electric field enhancement created during the collision of streamers could provide the necessary conditions for electron acceleration, even though some of the theoretical studies show that the duration of the electric field is not long enough to do so. The experimental data on laboratory discharges show that. when streamers of opposite polarity meet each other, a potential or ionization wave that renders the streamer channels conducting is initiated. This paper shows that these ionization waves that convert the discharge channels from weakly conducting to highly conducting are associated with electric fields large enough to accelerate electrons to relativistic energies.

Numerical modeling of cathode-directed streamers branching in strong electric fields

2016 ◽  
Author(s):  
Белогловский ◽  
Andrey Beloglovskiy ◽  
Федорова ◽  
A. Fedorova
Keyword(s):  
Numerical Modeling ◽  
Numerical Model ◽  
Electric Fields ◽  
Strong Field ◽  
Strong Electric Field ◽  
Three Dimensional ◽  
Strong Electric Fields ◽  
Electron Avalanches ◽  
Discharge Gap ◽  
Positive Streamer

A research of conditions of the branching of positive streamer in air in a strong electric field by the use a three-dimensional numerical model is presented. This model is based on the assumption that the development of large electron avalanches in the strong field in front of the streamer head leads to branching. Tendency for branching has been observed, if the ratio of the diameters of the streamer heads to the distance between them is not greater than 0.55. If this ratio is more than 0,55, merger of originally formed streamer heads has been observed, and then only one streamer develops in the discharge gap.

scholarly journals The Barkhausen Method to Investigate Powerful Processes during Action of Piezoelectric Igniters

2020 ◽  
Vol 26 (3) ◽  
pp. 358-362
Author(s):  
Linas ARDARAVIČIUS ◽  
Skirmantas KERŠULIS ◽  
Oleg KIPRIJANOVIČ ◽  
Česlovas ŠIMKEVIČIUS ◽  
Steponas AŠMONTAS
Keyword(s):  
Electric Fields ◽  
High Voltage ◽  
Impact Ionization ◽  
Domain Switching ◽  
Practical Importance ◽  
Total Duration ◽  
High Amplitude ◽  
High Voltage Pulse ◽  
Pulse Generation ◽  
The Impact

The Barkhausen method is proposed to clarify the cause of radiation of electromagnetic (EM) pulses during high voltage pulse generation by piezoelectric igniters (PIs). Wide bandwidth of the experimental setup was narrowed for a simultaneous registration of electric and detected EM pulses by a two-channel oscilloscope. The PI was loaded on a high ohmic resistance and high voltage pulses of 8 – 17 kV amplitude and up to 150 ms in total duration were registered. These pulses contained a series of short pulses called Barkhausen type pulses. Duration of these pulses having the relatively high amplitude was 30 – 40 ns. The registration revealed that the radiating EM pulse series corresponded to Barkhausen type pulse series. Short non-radiating negative pulses appearing during the saturated voltage growth were also observed and they had relaxation tails. The analysis showed that the EM pulses are caused as a result of domain switching with high voltage spikes at the PZT cylinders bases, where high electric fields are created. The activity of these switchings weakens when the “age” of PIs increases. The non-radiated pulses resulted from fast internal screening processes in the volume of the cylinders, accompanied by the impact ionization. The increase of the saturation and PI’s “age” causes lengthening of the relaxation tails. The results of practical importance for PIs in monitoring systems are placed. It is concluded that the Barkhausen method in wideband configuration is a convenient experimental arrangement for investigation of powerful processes in ferro-piezoelectric ceramics.

Tunneling and impact ionization at high electric fields in abrupt GaAs p-i-n structures

1997 ◽  
Vol 81 (7) ◽  
pp. 3181-3185 ◽  
Author(s):  
C. Benz ◽  
M. Claassen ◽  
D. Liebig
Keyword(s):  
Electric Fields ◽  
Impact Ionization ◽  
High Electric Fields
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