Influence of strong self-electric fields on the ion resonance instability in a nonneutral plasma column

1977 ◽  
Vol 20 (11) ◽  
pp. 1938 ◽  
Author(s):  
R. C. Davidson ◽  
Hwan-sup Uhm
Keyword(s):  
Electric Fields ◽  
Plasma Column ◽  
Nonneutral Plasma

Radial distribution of the plasma potential in a cylindrical plasma column with a longitudinal magnetic field

2021 ◽  
Vol 87 (4) ◽  
Author(s):  
G. Liziakin ◽  
A. Oiler ◽  
A. Gavrikov ◽  
N. Antonov ◽  
V. Smirnov
Keyword(s):  
Magnetic Field ◽  
Electric Fields ◽  
Radial Distribution ◽  
Plasma Column ◽  
Radial Profile ◽  
Plasma Potential ◽  
Symmetric System ◽  
Axially Symmetric ◽  
Cylindrical Plasma ◽  
Cylindrical Plasma Column

The possibility of controlling the electrostatic field distribution in plasma has yielded wide prospects for modern technologies. As a magnetic field primarily allows for creating electric fields in plasma, it serves as an additional obstacle for the current flow through a medium. In the present paper, an axially symmetric system is considered in which the magnetic field is directed along the axis and concentric electrodes are located at the ends. The electrodes are negatively biased. A model which solves the problem of the radial distribution of the plasma potential inside the cylindrical plasma column supported by the end electrodes is proposed. The most commonly encountered configurations of the electrical connection for the end electrodes are considered, and the particular solutions to the problem of the radial distribution are presented. The contribution of ions and electrons to the transverse conductivity is evaluated in detail. The influence of a thermionic element on the radial profile of the plasma potential is considered. To verify the proposed model, an experimental study of the reflex discharge is carried out with both cold electrodes and a thermionic element on the axis. A comparison of the computational model results with experimental data is given. The presented model makes it possible to solve the problem concerning the plasma potential distribution in the case of an arbitrary number of end electrodes, and also to take into account the inhomogeneity of the distribution of plasma density, neutral gas pressure and electron temperature along the radius.

The effect of radial electric fields on low frequency oscillations in a plasma column

1968 ◽  
Vol 10 (6) ◽  
pp. 641-644 ◽  
Author(s):  
L Enriques ◽  
A M Levine ◽  
G B Righetti
Keyword(s):  
Electric Fields ◽  
Plasma Column ◽  
Low Frequency ◽  
Low Frequency Oscillations

Structure of Bernstein Modes in a Nonneutral Plasma Column

1997 ◽  
Vol 78 (23) ◽  
pp. 4402-4405 ◽  
Author(s):  
S. C. Neu ◽  
G. J. Morales
Keyword(s):  
Plasma Column ◽  
Nonneutral Plasma

rf electric fields in an inhomogeneous magnetized plasma column

1978 ◽  
Vol 49 (8) ◽  
pp. 4366-4368
Author(s):  
C. R. Skipping ◽  
M. E. Oakes
Keyword(s):  
Electric Fields ◽  
Plasma Column ◽  
Magnetized Plasma

scholarly journals Application of Thomson scattering to helicon plasma sources

2020 ◽  
Vol 86 (3) ◽  
Author(s):  
R. Agnello ◽  
Y. Andrebe ◽  
H. Arnichand ◽  
P. Blanchard ◽  
T. De Kerchove ◽  
...  
Keyword(s):  
Electron Density ◽  
Electric Fields ◽  
Plasma Column ◽  
Coherent Scattering ◽  
Thomson Scattering ◽  
High Electron ◽  
Plasma Diagnostic ◽  
Ion Temperature ◽  
Helicon Plasma ◽  
Electron Density And Temperature

The possibility of performing electron density and temperature measurements in a high power helicon plasma is a crucial issue in the framework of the AWAKE (Advanced WAKefield Experiment) project, which demonstrates acceleration of particles using $\text{GeV}~\text{m}^{-1}$ electric fields in plasmas. For AWAKE, a helicon is currently envisaged as a candidate plasma source due to its capability for low electron and ion temperature, high electron density and production of an elongated plasma column. A plasma diagnostic to accurately determine the electron density in AWAKE regimes would be a valuable supporting tool. A demonstration Thomson scattering (TS) diagnostic was installed and successfully tested on the resonant antenna ion device (RAID) at the Swiss Plasma Center of Ecole Polytechnique Fédérale de Lausanne. RAID produces a helicon plasma column with characteristics similar to those of the AWAKE helicon source, and is therefore an optimal testbed for application to the AWAKE device. The spectrometer employed in RAID is based on polychromators which collect the light scattered by plasma electrons in spectrally filtered wavelength regions. Results from TS on RAID demonstrate conditions of electron density and temperature respectively of $n_{e}=1.10\,(\pm 0.19)\times 10^{19}~\text{m}^{-3}$ and $T_{e}=2.3\,(\pm 0.6)~\text{eV}$ in a steady-state discharge in an Ar plasma with 5 kW of RF power. If the same polychromator system is used for AWAKE, where the electron density attained is $2\times 10^{20}~\text{m}^{-3}$ , the contribution to measurement error due to coherent scattering is ${\sim}2.5\,\%$ . Presented here are details of the TS diagnostic and the first tests in RAID, and the expectations for the system when employed on the AWAKE device.

Control of Metal Alloy Oxidation with Electric Fields

1973 ◽  
Vol 31 ◽  
pp. 164-165
Author(s):  
R. R. Dils ◽  
P. S. Follansbee
Keyword(s):  
Electric Fields ◽  
Oxidation Process ◽  
Base Alloy ◽  
Oxide Surface ◽  
Platinum Electrodes ◽  
Insulating Layer ◽  
Iron Base Alloy ◽  
Alloy Oxidation ◽  
Aluminum Oxide Layer ◽  
And Control

Electric fields have been applied across oxides growing on a high temperature alloy and control of the oxidation of the material has been demonstrated. At present, three-fold increases in the oxidation rate have been measured in accelerating fields and the oxidation process has been completely stopped in a retarding field.The experiments have been conducted with an iron-base alloy, Pe 25Cr 5A1 0.1Y, although, in principle, any alloy capable of forming an adherent aluminum oxide layer during oxidation can be used. A specimen is polished and oxidized to produce a thin, uniform insulating layer on one surface. Three platinum electrodes are sputtered on the oxide surface and the specimen is reoxidized.

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