Eastern-European Journal of Enterprise Technologies
Plasma technology stands at the forefront of numerous industrial applications, offering versatile... more Plasma technology stands at the forefront of numerous industrial applications, offering versatile solutions from materials processing to aerospace engineering. This study employs a single Langmuir probe technique operating at atmospheric pressure to scrutinize the transformative impact of silica seeding on low-temperature arc plasma. The investigation unveils a dynamic interplay of electrons and ions within the plasma, unveiling key electrical properties. The I–V electrical properties of the arcs plasma before seeding, having a floating voltage of –39 V, demonstrate electron and ion currents for varied probe voltages. The electrons’ density is calculated to be 2.11×1013 m–3, and the electrons’ temperature is at 6.25 eV. The I–V characteristics show a floating potential of about –35 V and –37 V after seeding an arc plasma using silica in the presence of aluminum oxide (2 % by weight) powder and grain, respectively. After seeding, it is discovered that the electron temperature falls t...
Due to its numerous health advantages, coriander is one of the most used cooking ingredients. Thi... more Due to its numerous health advantages, coriander is one of the most used cooking ingredients. This paper describes the coriander plant's germination and growth after plasma treatment. The seeds are treated using the gliding arc for periods ranging from one minute to ten minutes. It is discovered that as treatment time is extended, the temperature of the seed rises while its weight continues to fall. The sixth and ninth days are used to calculate the germination rate. The study shows that the treatment time of plasma on seeds increases the hydrophilicity of coriander seeds. It is found that roots and shoots of seeds treated for ten minutes and eight minutes were significantly longer than the other seeds.
Meeting Abstracts of the Physical Society of Japan (Nihon Butsuri Gakkai koen gaiyoshu), 2003
The generation of the plasma by electron cyclotron resonance (ECR), a well known techniques, has ... more The generation of the plasma by electron cyclotron resonance (ECR), a well known techniques, has been increasingly used as an important tools in various purposes. The ECR plasma has high potential due to its wide range of field from nuclear fusion to plasma ...
This article deals about the experimental measurement of plasma potential, ion saturation current... more 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.
Plasma parameters like electron temperature (Te), electron density (ne), Debye length (D) and pl... more Plasma parameters like electron temperature (Te), electron density (ne), Debye length (D) and plasma frequency (fp) were measured using Langmuir probes in air seeded arc-plasma at low pressure range of 0.10 mbar to 0.16 mbar. Double slope method, Dote method and Interception method were used to calculate the electron temperature (Te) and mean value of electron temperatures obtained from these three methods was used to calculate the electron density, Debye length and plasma frequency. To investigate the effect of pressure and discharge voltage on the plasma parameters at low voltage and low pressure is the main objective of the study. It was observed that Te, ne and fp gradually increased respectively but D decreased on increasing the voltage from 500 V to 600 V. It was also observed that on increasing the pressure there was decrease in Te and D but increase in ne and fe.
Arc plasma is generated using low voltage dc power supply for the measurement of plasma parameter... more Arc plasma is generated using low voltage dc power supply for the measurement of plasma parameters such as floating potential and ion-concentration in the plasma seeded with molybdenum. Langmuir moving probe is used in order to measure the probe current at different values of the dc potential applied on the probe. A graph is plotted between the probe current and the probe potential, based on data at the atmospheric pressure, using the experimental set up in the gas discharge chamber for the single probe method. The floating potential is calculated to be 32V, and the average ion-concentration to be 1.43 - 10e16m3.
AbstractExperiments are performed to develop a pulsed corona plasma system for the production of... more AbstractExperiments are performed to develop a pulsed corona plasma system for the production of hydrogen and carbon nanotubes (CNTs), directly by methane decomposition, at atmo-spheric pressure ( 760 torr). The corona discharge is energized by a pulse voltage ( 7 kV) with ...
The importance of an acceptance angle in the plasma diagnostics with ion energy analyzers is inve... more The importance of an acceptance angle in the plasma diagnostics with ion energy analyzers is investigated by means of numerical simulations. It is shown that wide acceptance angles result in low energy tails in measured ion distribution functions (IDFx). For flowing plasmas or plasmas with beams, the orientation of the analyzer’s orifice gives different results due to bending of ion trajectories in the vicinity of the analyzer. It is demonstrated that the maximum in the IDFx is at energies lower than the plasma potential. Simulations are done with DIP3D, a three-dimensional particle-in-cell code.
The Njord device is an inductively coupled plasma device with 13.56 Mhz and 400-900 W RF power in... more The Njord device is an inductively coupled plasma device with 13.56 Mhz and 400-900 W RF power inserted into the working gas by means of a saddle antenna through a 13.8 cm ID pyrex tube. The source plasma expands through a 10 cm long port into a 0.6m diameter and ...
Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 1989
Electron cyclotron resonance plasmas were excited at a frequency of 2.45 GHz in chambers with dia... more Electron cyclotron resonance plasmas were excited at a frequency of 2.45 GHz in chambers with diameters smaller and larger than cutoff ones for fundamental TE and TM modes. Microwaves were introduced in the plasma chambers from the cw generator via a vacuum window and the microwave transmission line. It was found that microwave breakdowns at pressures 10−5–10−1 Torr (argon, nitrogen, oxygen) occurred at sites where the static magnetic field was 875 G (or close). In chambers with diameter smaller than cutoff, the breakdown occurred only near the vacuum window. A high absorption level of microwave power (>95%) was achieved in all explored chambers at microwave power P=300–1000 W. It occurred at areas where the static magnetic field was ∼875 G and the plasma density was Ncr=7.4×1010 cm−3. A high microwave power absorption level resulted in high plasma density up to Ne=1012 cm−3 at P=1000 W. No saturation in Ne=f(P) was observed. The shape and location of the high plasma density area...
Submitted for the GEC10 Meeting of The American Physical Society Numerical simulations of the inf... more Submitted for the GEC10 Meeting of The American Physical Society Numerical simulations of the influence of an ion beam on the plasma analyzer performance in Njord helicon device WOJCIECH MILOCH, LEKHA MISHRA, NJAL GULBRANDSEN, ASHILD FREDRIKSEN, Department of Physics and Technology, University of Tromso, Norway — Recent experiments in Njord helicon plasma device confirmed the presence of an ion beam in a weakly magnetized plasma downstream from the double layer region [1]. The measurements were carried out with the retarding-field energy analyzer (RFEA). Since the housing of RFEA is biased with respect to the plasma, the plasma current to the orifice can depend on the sheath structure in its vicinity, and on its orientation with respect to the flow. Throughout understanding of the problem is needed for the analysis of data from such measurements. Numerical simulations allow to address this problem self-consistently. We simulate weakly magnetized plasmas with an additional ion beam f...
Abstract: Experiments are performed to develop a pulsed corona discharge system for the conversio... more Abstract: Experiments are performed to develop a pulsed corona discharge system for the conversion of methane to hydrogen at atmospheric pressure (≃760 Torr) without using a catalyst. The corona discharge was energized by 1012 µs wide voltage pulses (≤7 kV) at a repetition rate of ...
Experiments are performrd to generate the hydrogen and carbon nanotubes from the decomposition of... more Experiments are performrd to generate the hydrogen and carbon nanotubes from the decomposition of methane using ultra short pulses under the atmospheric pressure. The results of discharge of methane obtained by the Mass Spectrometer are presented. Specially, the spectrum of hydrogen is presented under the different conditions. Carbon nanotube is observed by Scaning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The results of morphology of the carbon nanotubes are also presented. The results from this experiment could be useful for the industry in future.
Eastern-European Journal of Enterprise Technologies
Plasma technology stands at the forefront of numerous industrial applications, offering versatile... more Plasma technology stands at the forefront of numerous industrial applications, offering versatile solutions from materials processing to aerospace engineering. This study employs a single Langmuir probe technique operating at atmospheric pressure to scrutinize the transformative impact of silica seeding on low-temperature arc plasma. The investigation unveils a dynamic interplay of electrons and ions within the plasma, unveiling key electrical properties. The I–V electrical properties of the arcs plasma before seeding, having a floating voltage of –39 V, demonstrate electron and ion currents for varied probe voltages. The electrons’ density is calculated to be 2.11×1013 m–3, and the electrons’ temperature is at 6.25 eV. The I–V characteristics show a floating potential of about –35 V and –37 V after seeding an arc plasma using silica in the presence of aluminum oxide (2 % by weight) powder and grain, respectively. After seeding, it is discovered that the electron temperature falls t...
Due to its numerous health advantages, coriander is one of the most used cooking ingredients. Thi... more Due to its numerous health advantages, coriander is one of the most used cooking ingredients. This paper describes the coriander plant's germination and growth after plasma treatment. The seeds are treated using the gliding arc for periods ranging from one minute to ten minutes. It is discovered that as treatment time is extended, the temperature of the seed rises while its weight continues to fall. The sixth and ninth days are used to calculate the germination rate. The study shows that the treatment time of plasma on seeds increases the hydrophilicity of coriander seeds. It is found that roots and shoots of seeds treated for ten minutes and eight minutes were significantly longer than the other seeds.
Meeting Abstracts of the Physical Society of Japan (Nihon Butsuri Gakkai koen gaiyoshu), 2003
The generation of the plasma by electron cyclotron resonance (ECR), a well known techniques, has ... more The generation of the plasma by electron cyclotron resonance (ECR), a well known techniques, has been increasingly used as an important tools in various purposes. The ECR plasma has high potential due to its wide range of field from nuclear fusion to plasma ...
This article deals about the experimental measurement of plasma potential, ion saturation current... more 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.
Plasma parameters like electron temperature (Te), electron density (ne), Debye length (D) and pl... more Plasma parameters like electron temperature (Te), electron density (ne), Debye length (D) and plasma frequency (fp) were measured using Langmuir probes in air seeded arc-plasma at low pressure range of 0.10 mbar to 0.16 mbar. Double slope method, Dote method and Interception method were used to calculate the electron temperature (Te) and mean value of electron temperatures obtained from these three methods was used to calculate the electron density, Debye length and plasma frequency. To investigate the effect of pressure and discharge voltage on the plasma parameters at low voltage and low pressure is the main objective of the study. It was observed that Te, ne and fp gradually increased respectively but D decreased on increasing the voltage from 500 V to 600 V. It was also observed that on increasing the pressure there was decrease in Te and D but increase in ne and fe.
Arc plasma is generated using low voltage dc power supply for the measurement of plasma parameter... more Arc plasma is generated using low voltage dc power supply for the measurement of plasma parameters such as floating potential and ion-concentration in the plasma seeded with molybdenum. Langmuir moving probe is used in order to measure the probe current at different values of the dc potential applied on the probe. A graph is plotted between the probe current and the probe potential, based on data at the atmospheric pressure, using the experimental set up in the gas discharge chamber for the single probe method. The floating potential is calculated to be 32V, and the average ion-concentration to be 1.43 - 10e16m3.
AbstractExperiments are performed to develop a pulsed corona plasma system for the production of... more AbstractExperiments are performed to develop a pulsed corona plasma system for the production of hydrogen and carbon nanotubes (CNTs), directly by methane decomposition, at atmo-spheric pressure ( 760 torr). The corona discharge is energized by a pulse voltage ( 7 kV) with ...
The importance of an acceptance angle in the plasma diagnostics with ion energy analyzers is inve... more The importance of an acceptance angle in the plasma diagnostics with ion energy analyzers is investigated by means of numerical simulations. It is shown that wide acceptance angles result in low energy tails in measured ion distribution functions (IDFx). For flowing plasmas or plasmas with beams, the orientation of the analyzer’s orifice gives different results due to bending of ion trajectories in the vicinity of the analyzer. It is demonstrated that the maximum in the IDFx is at energies lower than the plasma potential. Simulations are done with DIP3D, a three-dimensional particle-in-cell code.
The Njord device is an inductively coupled plasma device with 13.56 Mhz and 400-900 W RF power in... more The Njord device is an inductively coupled plasma device with 13.56 Mhz and 400-900 W RF power inserted into the working gas by means of a saddle antenna through a 13.8 cm ID pyrex tube. The source plasma expands through a 10 cm long port into a 0.6m diameter and ...
Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 1989
Electron cyclotron resonance plasmas were excited at a frequency of 2.45 GHz in chambers with dia... more Electron cyclotron resonance plasmas were excited at a frequency of 2.45 GHz in chambers with diameters smaller and larger than cutoff ones for fundamental TE and TM modes. Microwaves were introduced in the plasma chambers from the cw generator via a vacuum window and the microwave transmission line. It was found that microwave breakdowns at pressures 10−5–10−1 Torr (argon, nitrogen, oxygen) occurred at sites where the static magnetic field was 875 G (or close). In chambers with diameter smaller than cutoff, the breakdown occurred only near the vacuum window. A high absorption level of microwave power (>95%) was achieved in all explored chambers at microwave power P=300–1000 W. It occurred at areas where the static magnetic field was ∼875 G and the plasma density was Ncr=7.4×1010 cm−3. A high microwave power absorption level resulted in high plasma density up to Ne=1012 cm−3 at P=1000 W. No saturation in Ne=f(P) was observed. The shape and location of the high plasma density area...
Submitted for the GEC10 Meeting of The American Physical Society Numerical simulations of the inf... more Submitted for the GEC10 Meeting of The American Physical Society Numerical simulations of the influence of an ion beam on the plasma analyzer performance in Njord helicon device WOJCIECH MILOCH, LEKHA MISHRA, NJAL GULBRANDSEN, ASHILD FREDRIKSEN, Department of Physics and Technology, University of Tromso, Norway — Recent experiments in Njord helicon plasma device confirmed the presence of an ion beam in a weakly magnetized plasma downstream from the double layer region [1]. The measurements were carried out with the retarding-field energy analyzer (RFEA). Since the housing of RFEA is biased with respect to the plasma, the plasma current to the orifice can depend on the sheath structure in its vicinity, and on its orientation with respect to the flow. Throughout understanding of the problem is needed for the analysis of data from such measurements. Numerical simulations allow to address this problem self-consistently. We simulate weakly magnetized plasmas with an additional ion beam f...
Abstract: Experiments are performed to develop a pulsed corona discharge system for the conversio... more Abstract: Experiments are performed to develop a pulsed corona discharge system for the conversion of methane to hydrogen at atmospheric pressure (≃760 Torr) without using a catalyst. The corona discharge was energized by 1012 µs wide voltage pulses (≤7 kV) at a repetition rate of ...
Experiments are performrd to generate the hydrogen and carbon nanotubes from the decomposition of... more Experiments are performrd to generate the hydrogen and carbon nanotubes from the decomposition of methane using ultra short pulses under the atmospheric pressure. The results of discharge of methane obtained by the Mass Spectrometer are presented. Specially, the spectrum of hydrogen is presented under the different conditions. Carbon nanotube is observed by Scaning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The results of morphology of the carbon nanotubes are also presented. The results from this experiment could be useful for the industry in future.
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Papers by Lekha Nath Mishra