EMERGING TRENDS IN WALL-FREE HALL THRUSTERS DEVELOPMENT

2D-hybrid model was created for the proposed new type accelerator with a virtual cathode which allows to avoid sputtering of the cathode surface and to preserve the dynamics of accelerated ions. In the framework of the model, it was shown that ions first form a positive space charge in the system center, and eventually, under an ac-tion of created own electric field, emerge from both ends of the system.

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The structure of the impulse corona in a rod/plane gap I. The positive corona

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1970.0026 ◽

1970 ◽

Vol 315 (1520) ◽

pp. 1-25 ◽

Cited By ~ 34

Keyword(s):

Spatial Distribution ◽

Electric Field ◽

Space Charge ◽

Negative Ions ◽

Corona Discharges ◽

Theoretical Derivation ◽

Plane Electrode ◽

Positive Space Charge ◽

Positive Ion ◽

Positive Space

The dissipation of space charge following the growth of impulse corona discharges in positive rod/earthed plane gaps has been measured with an electrostatic fluxmeter. A method is described to determine the spatial distribution and magnitude of the space charge together with the associated electric field. Initial positive ion densities of up to 100 μC m -3 have been found. The total positive space charge deposited in a 40 cm gap at 160 kV is 500 nC. Electrons emitted from the plane electrode as a result of corona channels crossing the gap are shown to be trapped in the discharge space as negative ions. The recovery of the gap over several seconds is largely due to ionic drift to the electrodes. A theoretical derivation of the rate of deionization agrees with observed values.

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Electrical Breakdown in Air and in SF6

Australian Journal of Physics ◽

10.1071/ph950453 ◽

1995 ◽

Vol 48 (3) ◽

pp. 453 ◽

Cited By ~ 6

Author(s):

R Morrow ◽

JJ Lowke

Keyword(s):

Electric Field ◽

Electric Field Distribution ◽

Electrical Breakdown ◽

Negative Ions ◽

Continuity Equations ◽

Positive Ions ◽

Positive Space Charge ◽

Attachment Coefficient ◽

Positive Space ◽

Positive Point

A theory is presented for the development of streamers from a positive point in atmospheric air. The continuity equations for electrons, positive ions, and negative ions are solved simultaneously with Poisson's equation. For an applied voltage of 20 kV across a 20 mm gap, streamers are predicted to cross the gap in 26 ns, and the calculated streamer velocities are in fair agreement with experiment. When the gap is increased to 50 mm for the same voltage, the streamer is predicted not to reach the cathode. In this case an intense electric field front rapidly propagates about 35 mm into the gap in 200 ns. For a further 9�5 �s the streamer slowly moves into the gap, until the electric field at the head of the streamer collapses, and the streamer front stops moving. Finally, only positive space-charge remains; this moves away from the point, allowing the field near the point to recover, giving rise to a secondary discharge near the anode. The electric field distribution is shown to be quite different from that found previously for SF6; this is explained by the much lower attachment coefficient in air compared with that in SF6. These results show that streamers in air have a far greater range than streamers in SF6. This greater range cannot be explained by comparison of the values of E*, the electric field at which ionisation equals attachment.

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Continuous Positive Space Charge in Silicone Rubber Insulation

2018 IEEE 2nd International Conference on Dielectrics (ICD) ◽

10.1109/icd.2018.8514729 ◽

2018 ◽

Author(s):

Weiwang Wang ◽

Shengtao Li ◽

Dongri Xie ◽

Yasuhiro Tanaka

Keyword(s):

Space Charge ◽

Silicone Rubber ◽

Positive Space Charge ◽

Positive Space

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Thermally Stimulated Currents in the Range of Unity Gain Factor

Zeitschrift für Naturforschung A ◽

10.1515/zna-1971-0507 ◽

1971 ◽

Vol 26 (5) ◽

pp. 819-823

Author(s):

J. A. Bragagnolo ◽

G. Dussel ◽

K. W. Böer ◽

G. A. Dussel

Keyword(s):

Space Charge ◽

Space Charge Region ◽

Thermal Quenching ◽

Gain Factor ◽

Thermally Stimulated Current ◽

Thermally Stimulated Currents ◽

Positive Space Charge ◽

Unity Gain ◽

Positive Space

Abstract Thermally stimulated current-curves in CdS platelets with slit electrodes change their character when the photoelectric gain-factor increases above one. Here the photocurrent remains essentially frozen-in up to temperatures at which marked thermal quenching sets in. A positive space charge region is assumed to be responsible for the frozen-in photocurrent. A reliable TSC-analysis of the trap distribution can be conducted only for gain factors considerably below one.

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