scholarly journals EVALUATION OF GROWTH AND SEED YIELD OF TWO CULTIVARS OF FLAX

2021 ◽  
Vol 03 (04) ◽  
pp. 17-22
Author(s):  
Hanaa Khudhaier Mohammed Ali AL-HAIDARY ◽  
A.F.Abed AL-KHADER
Keyword(s):  
Aluminum Oxide ◽  
Vacuum Chamber ◽  
Plasma Potential ◽  
Discharge Voltage ◽  
Dust Particles ◽  
Saturation Current ◽  
Air Plasma ◽  
Plasma Region ◽  
Dc System ◽  
Plasma Characteristics

In this research, we have conducted an experimental study of the dusty plasma to the Aluminum oxide (Al2O3) dust material with a grain radius of (0.2) µm to (0.6) µm. In the experiment, we use air in the vacuum chamber system under different low pressure (0.1-0.8) Torr. The results have showed that the existence of dust particles in air plasma is equal to the Paschen minimum which is (0.4) Torr with Al2O3 dusty and without dust. The effect of Al2O3 dust particles on the plasma characteristics like floating potential (Vf), plasma potential (Vp), electron saturation current (Ies), temperature of the electron (Te), density of electron (ne) and density of ion (ni) of the DC system that can be calculated in the glow-discharge region. Parameter measurements are taken by four cylindrical probes which are diagnosed at a distance of (40) mm from the cathode diameter, the Paschen minimum at a pressure of (0.4) Torr. The plasma potential and the probe's floating voltage become more negative when dust is immersed in the plasma region. The features of these parameters show that the current discharge decreases while the discharge voltage increases when the aluminum oxide dust particles that are incorporated. And vice versa was in the absence of dust. Electron density increases in the existence of dust particles which causes the electron temperature to decrease.

scholarly journals LANGMUIR PROBE TO CHARACTERIZE THE DUST PLASMA OF ALUMINUM OXIDE (AL2O3) PRODUCED BY DC PLASMA SYSTEM

2021 ◽  
Vol 03 (04) ◽  
pp. 23-34
Author(s):  
Ala F. AHMED
Keyword(s):  
Aluminum Oxide ◽  
Vacuum Chamber ◽  
Plasma Potential ◽  
Discharge Voltage ◽  
Dust Particles ◽  
Saturation Current ◽  
Air Plasma ◽  
Plasma Region ◽  
Dc System ◽  
Plasma Characteristics

In this research, we have conducted an experimental study of the dusty plasma to the Aluminum oxide (Al2O3) dust material with a grain radius of (0.2) µm to (0.6) µm. In the experiment, we use air in the vacuum chamber system under different low pressure (0.1-0.8) Torr. The results have showed that the existence of dust particles in air plasma is equal to the Paschen minimum which is (0.4) Torr with Al2O3 dusty and without dust. The effect of Al2O3 dust particles on the plasma characteristics like floating potential (Vf), plasma potential (Vp), electron saturation current (Ies), temperature of the electron (Te), density of electron (ne) and density of ion (ni) of the DC system that can be calculated in the glow-discharge region. Parameter measurements are taken by four cylindrical probes which are diagnosed at a distance of (40) mm from the cathode diameter, the Paschen minimum at a pressure of (0.4) Torr. The plasma potential and the probe's floating voltage become more negative when dust is immersed in the plasma region. The features of these parameters show that the current discharge decreases while the discharge voltage increases when the aluminum oxide dust particles that are incorporated. And vice versa was in the absence of dust. Electron density increases in the existence of dust particles which causes the electron temperature to decrease.

scholarly journals Experimental study for the properties of Fe3O4 dusty plasma using the air in vacuum chamber system

2019 ◽  
Vol 13 (26) ◽  
pp. 151-159
Author(s):  
Ala’ Fadhil Ahmed
Keyword(s):  
Experimental Study ◽  
Discharge Current ◽  
Current System ◽  
Debye Length ◽  
Dust Particles ◽  
Floating Potential ◽  
Saturation Current ◽  
Air Plasma ◽  
Plasma Region ◽  
Plasma Parameters

In this work, we carried out an experimental study of thedustyplasma by taking the dust material Fe3O4 with radius of the any grain0.1μm - 0.5μm. In experiment we use air in the vacuum chambersystem under different low pressure (0.1-1) Torr. The resultsillustrated that the present of dust particles in the air plasma did noteffect on Paschen minimum which is 0.5 without dust and with Fe3O4dusty grains.The effect of Fe3O4 dust particles on plasma parameters can benotice in direct current system in glow discharge region. The plasmaparameters which were studied in this work represent plasmapotential, floating potential,electron saturation current, temperatureof the electron, the density of the (electron, ion), and Debye length.The measurements of parameters are taken by four cylindrical probeswhich diagnosed at distance 4cm from the diameter of the cathode inPaschen minimum at pressure 0.5 Torr. The diameter profiles ofplasma parameters in the present of dust are non- uniform. Plasmapotential and the floating potential of probe becomes more negativelywhen the dust immersed into plasma region. The electron densityincreases in the present of dust particle which lead to decrease theelectron temperature and Debye length. The behavior of thoseparameters shows the discharge current and discharge voltageincreases without dust while the discharge current and voltagedecreases when Fe3O4 dust particles embedded.

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.

Effect of discharge voltage on bi-Maxwellian electrons in the diffusion plasma region of a double plasma device

2013 ◽  
Vol 79 (5) ◽  
pp. 913-920
Author(s):  
M. K. MISHRA ◽  
A. PHUKAN ◽  
M. CHAKRABORTY
Keyword(s):  
Probability Function ◽  
Energetic Electron ◽  
Plasma Potential ◽  
Discharge Voltage ◽  
Diffusion Region ◽  
Plasma Region ◽  
Temperature Plasma ◽  
Plasma Device ◽  
Double Plasma Device ◽  
Mesh Grid

AbstractThe effect of discharge voltage on bi-Maxwellian electrons in the diffusion region of a double plasma device has been studied. The increase in discharge voltage enhances the flux of ionizing electrons to the diffusion region separated by a mesh grid. This energetic electron flux in turn affects other important parameters such as density, electron temperature, plasma potential and floating potential in the diffusion region. Furthermore, the dependence of density and temperature of both ionizing and plasma electrons on discharge voltage is investigated. The electron energy probability function obtained from probe data also indicates the bi-Maxwellian nature of electrons.

scholarly journals Electrostatic Fragmentation of Dust Particles in Laboratory

1992 ◽  
Vol 150 ◽  
pp. 17-18
Author(s):  
J. Svestka ◽  
E. Grün
Keyword(s):  
Tensile Strength ◽  
Power Law ◽  
Vacuum Chamber ◽  
Ion Beams ◽  
Dust Particles ◽  
Laboratory Work ◽  
Experimental Laboratory ◽  
Size Of Particles ◽  
Electrically Charged

Experimental laboratory work on simulation of the electrostatic fragmentation was started with loosely bound Al2O3 particles of 1 to 10 micrometers size. These particles were suspended in an electrodynamic quadrupole inside a vacuum chamber and electrically charged by ion beams of energies up to 5 keV. The electrostatic fragmentation was observed and derived tensile strengths of the particles range from 103 to 105 Pa what is compatible with theoretical estimates. A dependence of the tensile strength on the size of particles has been found. This dependence can be well fitted by inverse square power law.

scholarly journals Dynamics of bipolar HiPIMS discharges by plasma potential probe measurements

2022 ◽  
Author(s):  
Michal Zanáška ◽  
Daniel Lundin ◽  
Nils Brenning ◽  
Hao Du ◽  
Pavel Dvorak ◽  
...  
Keyword(s):  
Pulse Length ◽  
Plasma Potential ◽  
Ion Acceleration ◽  
Time Interval ◽  
Saturation Current ◽  
Target Region ◽  
Peak Current ◽  
Positive Pulse ◽  
Positive Voltage ◽  
Substrate Position

Abstract The plasma potential at a typical substrate position is studied during the positive pulse of a bipolar high-power impulse magnetron sputtering (bipolar HiPIMS) discharge with a Cu target. The goal of the study is to identify suitable conditions for achieving ion acceleration independent on substrate grounding. We find that the time-evolution of the plasma potential during the positive pulse can be separated into several distinct phases, which are highly dependent on the discharge conditions. This includes exploring the influence of the working gas pressure (0.3 – 2 Pa), HiPIMS peak current (10 – 70 A corresponding to 0.5 – 3.5 A/cm2), HiPIMS pulse length (5 – 60 μs) and the amplitude of the positive voltage U+ applied during the positive pulse (0 – 150 V). At low enough pressure, high enough HiPIMS peak current and long enough HiPIMS pulse length, the plasma potential at a typical substrate position is seen to be close to 0 V for a certain time interval (denoted phase B) during the positive pulse. At the same time, spatial mapping of the plasma potential inside the magnetic trap region revealed an elevated value of the plasma potential during phase B. These two plasma potential characteristics are identified as suitable for achieving ion acceleration in the target region. Moreover, by investigating the target current and ion saturation current at the chamber walls, we describe a simple theory linking the value of the plasma potential profile to the ratio of the available target electron current and ion saturation current at the wall.

scholarly journals Measurement of Plasma Potential, Ion Saturation Current and Mach number using Retarding Field Energy Analyzer

2021 ◽  
Vol 7 (2) ◽  
pp. 76-80
Author(s):  
L. N. Mishra ◽  
Å. Fredriksen
Keyword(s):  
Mach Number ◽  
Plasma Source ◽  
Diffusion Chamber ◽  
Plasma Potential ◽  
Field Energy ◽  
Saturation Current ◽  
Energy Analyzer ◽  
Temperature Plasma ◽  
Helicon Plasma ◽  
Side Walls

This article deals about the experimental measurement of plasma potential, ion saturation current and Mach number obtained with the variation of power, operating gas pressure and radial position using retarding field energy analyzer. We employed a retarding field energy analyzer by rotating with different angles such as 0° (facing toward source), 90° (facing side walls) and 180° (facing opposite the source). The coil current is varied from 0 to 15 A to produce the magnetic field which is used to confine the plasma. The flow of plasma has been characterized which was found to be subsonic. The low-temperature plasma is produced by means of a 13.56 MHz helicon plasma source at 300-1000 kW radio frequency power. The plasma is expanding from 13.8 cm diameter source into a 150 cm long diffusion chamber of 60 cm diameter.

Dust vortices in a direct current glow discharge plasma: a delicate balance between ion drag and Coulomb force

2019 ◽  
Vol 85 (1) ◽  
Author(s):  
Sayak Bose ◽  
M. Kaur ◽  
P. K. Chattopadhyay ◽  
J. Ghosh ◽  
Edward Thomas ◽  
...  
Keyword(s):  
Glow Discharge ◽  
Discharge Current ◽  
Discharge Plasma ◽  
Coulomb Force ◽  
Plasma Potential ◽  
Glow Discharge Plasma ◽  
Dust Particles ◽  
Charged Dust ◽  
Surface Evolution

Dust vortices with a void at the centre are reported in this paper. The role of the spatial variation of the plasma potential in the rotation of dust particles is studied in a parallel plate glow discharge plasma. Probe measurements reveal the existence of a local potential minimum in the region of formation of the dust vortex. The minimum in the potential well attracts positively charged ions, while it repels the negatively charged dust particles. Dust rotation is caused by the interplay of the two oppositely directed ion drag and Coulomb forces. The balance between these two forces is found to play a major role in the radial confinement of the dust particles above the cathode surface. Evolution of the dust vortex is studied by increasing the discharge current from 15 to 20 mA. The local minimum of the potential profile is found to coincide with the location of the dust vortex for both values of discharge currents. Additionally, it is found that the size of the dust vortex as well as the void at the centre increases with the discharge current.

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