scholarly journals Influence of an external circuit on the plasma parameters in the channel of the radio-frequency accelerator with a closed electron drift

2021 ◽  
pp. 24-30
Keyword(s):  
Direct Current ◽  
Plasma Source ◽  
Plasma Potential ◽  
Electron Drift ◽  
Axial Distribution ◽  
Plasma Parameters ◽  
Local Maxima ◽  
First Case ◽  
Temperature Of Electrons ◽  
Closed Electron

The axial distribution of the plasma potential, concentration and temperature of electrons in an RF capacitive plasma source with the geometry of an accelerator with a closed electron drift is experimentally investigated in this work. Two cases of the external electrical discharge circuit are considered. In the first case, the electrodes were closed by direct current, in the second, they were opened. It is shown that direct current closure of the electrodes leads to a significant increase in the plasma potential and electron concentration. In a number of cases, local maxima of temperature and plasma density are observed near the electrodes, which can be associated with the occurrence of azimuthal electron drift in crossed electric and magnetic fields.

scholarly journals Influence of an external circuit on the plasma parameters in the channel of the radio-frequency accelerator with a closed electron drift

2021 ◽  
pp. 24-30
Keyword(s):  
Direct Current ◽  
Plasma Source ◽  
Plasma Potential ◽  
Electron Drift ◽  
Axial Distribution ◽  
Plasma Parameters ◽  
Local Maxima ◽  
First Case ◽  
Temperature Of Electrons ◽  
Closed Electron

The axial distribution of the plasma potential, concentration and temperature of electrons in an RF capacitive plasma source with the geometry of an accelerator with a closed electron drift is experimentally investigated in this work. Two cases of the external electrical discharge circuit are considered. In the first case, the electrodes were closed by direct current, in the second, they were opened. It is shown that direct current closure of the electrodes leads to a significant increase in the plasma potential and electron concentration. In a number of cases, local maxima of temperature and plasma density are observed near the electrodes, which can be associated with the occurrence of azimuthal electron drift in crossed electric and magnetic fields.

scholarly journals Prediction of Axial Variation of Plasma Potential in Helicon Plasma Source Using Linear Regression Techniques

2020 ◽  
Vol 5 (6) ◽  
pp. 1284-1299
Author(s):  
Vipin Shukla ◽  
Mainak Bandyopadhyay ◽  
Vivek Pandya ◽  
Arun Pandey
Keyword(s):  
Plasma Source ◽  
Plasma Potential ◽  
Ion Source ◽  
Training Data ◽  
Negative Ion ◽  
Physical Parameters ◽  
Plasma Parameters ◽  
Data Set ◽  
Regression Techniques ◽  
Analytical Expressions

Analytical expressions are used frequently for the determination and analysis of plasma parameters. Instead of relying on analytical expressions, the proposed method uses regression techniques supplemented with experimental data for the selected parameters (plasma potential). In the machine learning domain, this is equivalent to the creation of the training data set, building and training the model, and authenticating the result over a range of desired physical parameters. An experimental dataset is built using two axially movable Triple Langmuir Probe (TLPs) which measure the electron temperature, electron density, and electric potential of a plasma. The presented work is a first step towards developing an inclusive model with detailed kinetic simulations capable of characterizing the HELicon Experiment for Negative ion source (HELEN-I) with a single driver. Plasma potential is measured at different axial locations (z) by keeping pressure fixed at 6 mTorr.

Experimental studies of iodine stationary plasma thruster

2019 ◽  
pp. 81-90
Author(s):  
Boris A. Sokolov ◽  
Pavel A. Shcherbina ◽  
Ivan B. Sishko ◽  
Aleksandr V. Shipovskiy Aleksandr ◽  
Aleksandr A. Lyapin ◽  
...  
Keyword(s):  
Experimental Studies ◽  
Thermal Conditions ◽  
Economic Viability ◽  
Electron Drift ◽  
Experimental Facility ◽  
Operational Mode ◽  
Stationary Plasma Thruster ◽  
Stationary Plasma ◽  
Plasma Thruster ◽  
Closed Electron

The paper demonstrates the feasibility of using iodine as propellant for thrusters with closed electron drift and its economic viability. It describes a test setup for running experiments. It provides the results of experimental studies of the stationary plasma thruster using iodine as its propellant with xenon gas-passage hollow cathode, as well as of the operational mode of the thruster where a mixture of xenon and iodine is used. During tests gas dynamic and electrical properties of the thruster were analyzed. Thermal conditions in the iodine storage and supply system were studied. Conclusions were drawn on how the test object could be improved and upgraded. The paper describes the option to use a thermionic non-flow cathode as the compensator cathode for the operation of the iodine thruster. The paper provides the results of an experimental study of the prototype non-flow compensator cathode in diode mode. Based on the results of the studies an experimental facility was built for testing a thruster with non-flow compensator cathode. Key words: cathode, compensator cathode, thruster with closed electron drift, stationary plasma thruster, iodine.

Long-pulse plasma source for SMOLA helical mirror

2021 ◽  
Vol 87 (2) ◽  
Author(s):  
Ivan A. Ivanov ◽  
V. O. Ustyuzhanin ◽  
A. V. Sudnikov ◽  
A. Inzhevatkina
Keyword(s):  
Magnetic Field ◽  
Gas Flow ◽  
Supply Voltage ◽  
Hydrogen Plasma ◽  
Plasma Source ◽  
Lanthanum Hexaboride ◽  
Plasma Stream ◽  
Plasma Parameters ◽  
Plasma Properties ◽  
Plasma Gun

A plasma gun for forming a plasma stream in the open magnetic mirror trap with additional helicoidal field SMOLA is described. The plasma gun is an axisymmetric system with a planar circular hot cathode based on lanthanum hexaboride and a hollow copper anode. The two planar coils are located around the plasma source and create a magnetic field of up to 200 mT. The magnetic field forms the magnetron configuration of the discharge and provides a radial electric insulation. The source typically operates with a discharge current of up to 350 A in hydrogen. Plasma parameters in the SMOLA device are Ti ~ 5 eV, Te ~ 5–40 eV and ni ~ (0.1–1)  × 1019 m−3. Helium plasma can also be created. The plasma properties depend on the whole group of initial technical parameters: the cathode temperature, the feeding gas flow, the anode-cathode supply voltage and the magnitude of the cathode magnetic insulation.

scholarly journals Studies of non-conventional configuration closed electron drift thrusters

2001 ◽  
Author(s):  
Y. Raitses ◽  
D. Staack ◽  
A. Smirnov ◽  
A. Litvak ◽  
L. Dorf ◽  
...  
Keyword(s):  
Electron Drift ◽  
Closed Electron

Electron drift caused by rf field gradient creates many plasma phenomena: An attempt to distinguish the cause and the effect

2011 ◽  
Vol 78 (2) ◽  
pp. 165-174 ◽  
Author(s):  
C. L. XAPLANTERIS ◽  
E. D. FILIPPAKI ◽  
I. S. MISTAKIDIS ◽  
L. C. XAPLANTERIS
Keyword(s):  
Experimental Data ◽  
Steady State ◽  
Low Temperature ◽  
Mathematical Models ◽  
Field Gradient ◽  
Collision Frequency ◽  
The Other ◽  
Frequency Effect ◽  
Electron Drift ◽  
Plasma Parameters

AbstractMany experimental data along with their theoretical interpretations on the rf low-temperature cylindrical plasma have been issued until today. Our Laboratory has contributed to that research by publishing results and interpretative mathematical models. With the present paper, two issues are being examined; firstly, the estimation of electron drift caused by the rf field gradient, which is the initial reason for the plasma behaviour, and secondly, many new experimental results, especially the electron-neutral collision frequency effect on the other plasma parameters and quantities. Up till now, only the plasma steady state was taken into consideration when a theoretical elaboration was carried out, regardless of the cause and the effect. This indicates the plasma's complicated and chaotic configuration and the need to simplify the problem. In the present work, a classification about the causality of the phenomena is attempted; the rf field gradient electron drift is proved to be the initial cause.

scholarly journals COMPARISON BETWEEN 2D TURBULENCE MODEL ESEL AND EXPERIMENTAL DATA FROM AUG AND COMPASS TOKAMAKS

2015 ◽  
Vol 55 (2) ◽  
pp. 128-135 ◽  
Author(s):  
Peter Ondac ◽  
Jan Horacek ◽  
Jakub Seidl ◽  
Petr Vondrácek ◽  
Hans Werner Müller ◽  
...  
Keyword(s):  
Turbulent Transport ◽  
Plasma Potential ◽  
Density Fluctuations ◽  
Tokamak Plasma ◽  
Plasma Parameters ◽  
Fluid Turbulence ◽  
Radial Profiles ◽  
Parallel Dynamics ◽  
Two Machines ◽  
Probe Measurements

<!-- p, li { white-space: pre-wrap; } --><p style="text-indent: 0px; margin: 0px;">In this article we have used the 2D fluid turbulence numerical model, ESEL, to simulate turbulent transport in edge tokamak plasma. Basic plasma parameters from the ASDEX Upgrade and COMPASS tokamaks are used as input for the model, and the output is compared with experimental observations obtained by reciprocating probe measurements from the two machines. Agreements were found in radial profiles of mean plasma potential and temperature, and in a level of density fluctuations. Disagreements, however, were found in the level of plasma potential and temperature fluctuations. This implicates a need for an extension of the ESEL model from 2D to 3D to fully resolve the parallel dynamics, and the coupling from the plasma to the sheath.</p>

scholarly journals Effect of the gas puff location on the divertor plasma properties in COMPASS tokamak

2020 ◽  
Vol 1492 (1) ◽  
pp. 012003
Author(s):  
M Dimitrova ◽  
M Tomes ◽  
Tsv Popov ◽  
R Dejarnac ◽  
J Stockel ◽  
...  
Keyword(s):  
Electron Temperature ◽  
Vacuum Chamber ◽  
Plasma Potential ◽  
Saturation Current ◽  
Langmuir Probes ◽  
Plasma Parameters ◽  
Plasma Properties ◽  
Low Field ◽  
Saturation Current Density ◽  
Deuterium Gas

Abstract Langmuir probes are used to study the plasma parameters in the divertor during deuterium gas puff injection on the high- (HFS) or low-field sides (LFS). The probe data were processed to evaluate the plasma potential and the electron temperatures and densities. A difference was found in the plasma parameters depending on the gas puff location. In the case of a gas puff on the LFS, the plasma parameters changed vastly, mainly in the inner divertor – the plasma potential, the ion saturation-current density and the electron temperature dropped. After the gas puff, the electron temperature changed from 10-15 eV down to within the 5-9 eV range. As a result, the parallel heat-flux density decreased. At the same time, in the outer divertor the plasma parameters remained the same. We thus concluded that using a gas puff on the LFS will facilitate reaching a detachment regime by increasing the density of puffed neutrals. When the deuterium gas puff was on the HFS, the plasma parameters in the divertor region remained almost the same before and during the puff. The electron temperature decreased with just few eV as a result of the increased amount of gas in the vacuum chamber.

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