The Journal of Technological and Space Plasmas
JTSP is an independent, peer-reviewed open-access online journal.
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The Hamilton-Jacobi Equation and its Application to Nonlinear Beam Dynamics: Comparison of Approaches
The rarely used Hamilton-Jacobi equation has been utilized as an elegant way to find the trajectories of mechanical systems and to derive symplectic maps. Further, the exact solution in kick approximation of Hamilton’s equations of motion in interaction representation is written as a generalized one-turn twist map. One can imagine that the nonlinear kick comes first, followed by the one-period rotation along the machine circumference, or a second alternative in which the one-period rotation occurs before the kick. There is a difference in the result of solving Hamilton’s equations between the two cases, which is expressed in obtaining a standard forward twist map in the first case, or alternatively a backward map in the second one. This nontrivial and intuitively unclear peculiarity is usually ignored/overlooked in practically all specialized references on the topic. Finally, the statistical properties and the behavior of the density distribution of a particle beam in configuration space under the influence of an isolated sextupole have been studied.
Copyright (c) 2026 Stephan Tzenov https://creativecommons.org/licenses/by/4.0
Measured electron energy distribution functions in inverted hydrogen fireballs
Electron energy distribution functions (EEDFs) play an important role in many different types of plasmas. Their shape characterises the degree of thermal equilibrium, while the EEDF mean value is proportional to the electron temperature, if the distribution function is Maxwellian. In this paper we present the first measurements of EEDFs of electrons inside and outside an inverted fireball (IFB) plasma. It turns out that the EEDF inside the IFB plasma shows larger contributions from hot electrons, while on the outside there are two distinguished electron populations, namely cold bulk electrons and hot tail electrons. The measurements were carried out at low pressure of around 5 Pa, which is typical for IFB experiments. The measurements were performed with a movable Langmuir probe system, and the obtained I-V curves were used to calculate the EEDF. The measurements indicate a spread in the EEDF inside the IFB as well as a shift to higher peak values of the electron temperature. It was shown that there are basically two populations of electrons. There are the bulk electrons, which are relatively cold and a smaller number of hot electrons in the tail of the EEDF. Particularly, the electrons close to the wall of the IFB anode show a significantly broader EEDF, which indicates that they deviate from a Maxwellian distribution function and deviate, thus, from thermal equilibrium.
Copyright (c) 2026 Johannes Gruenwald, Jacob Reynvaan https://creativecommons.org/licenses/by/4.0
Environmentally Friendly Sterilization and Enhancement of Cellulose Using RF Plasma Process
Cellulose-based materials are widely used in wound care due to their biocompatibility, biodegradability, and fluid-handling capacity. While chemical functionalisation is commonly employed to impart antimicrobial activity, the role of physical surface modification in regulating bacterial adhesion remains less explored. In this study, low-pressure radiofrequency (RF) oxygen plasma was used as a dry and environmentally friendly approach to modify the surface of medical-grade cellulose without altering its bulk properties. Plasma treatment was performed in both glow and afterglow regions, enabling controlled exposure to reactive oxygen species. Surface modification resulted in pronounced nanoscale roughening and fissured topography of cellulose microfibers, as observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Plasma-induced oxidation of the cellulose surface, characterised previously by X-ray photoelectron spectroscopy (XPS), accompanied the morphological changes. Bacterial adhesion experiments using a non-pathogenic Escherichia coli model strain revealed significantly enhanced bacterial attachment on plasma-treated cellulose compared to untreated controls, with the strongest effect observed for glow-region treatments. The increased adhesion is attributed to the combined effects of surface roughness amplification and plasma-induced chemical functionalisation, which together increase the effective contact area between bacteria and the substrate. Rather than aiming to inhibit bacterial attachment, this work explores a physico-mechanical design concept in which surface topography is intentionally modified to favour bacterial binding to the dressing material itself. The observed behaviour is interpreted qualitatively using concepts from membrane mechanics as a phenomenological framework, without invoking a quantitative predictive model. While the present study does not assess net bacterial load reduction in wound environments, it establishes a materials-level basis for a “capture-and-remove” hypothesis, whereby preferential bacterial adhesion to a removable dressing could contribute to microbial load management during dressing changes. These findings highlight the potential of plasma surface engineering as a versatile tool for tailoring the biointerface of cellulose-based biomedical materials.
Copyright (c) 2025 Kristina Eleršič Filipič, Marija Gorjanc, Ita Junkar https://creativecommons.org/licenses/by/4.0
Frobenius-Perron Operator Approach to the Beam-Beam Interaction in Circular Colliders
Unlike most publications devoted to the application of the self-consistent method of the nonlinear Vlasov-Poisson system to the study of beam-beam interaction, in this article an alternative strategy using the elegant approach of the Frobenius-Perron operator for symplectic twist maps has been developed. A detailed analysis of the establishment of an equilibrium density distribution in phase space, as well as the behavior of the perturbed distribution function with respect to the coherent stability of the two beams, has been carried out. Using the Renormalization Group technique for the reduction of the Frobenius-Perron operator, the case where the unperturbed rotation frequency (unperturbed betatron tune) of the map is far from any structural resonance driven by the beam-beam kick perturbation has been analyzed in detail. It has been shown that up to second order in the beam-beam parameter, the renormalized map propagator with nonlinear stabilization describes a random walk of the angle variable, implying that there exists an equilibrium distribution function depending only on the action variable. The linearized Frobenius-Perron operators for each beam imply a discrete form of the linearized Vlasov equations, which essentially comprises a new method for calculating coherent beam-beam instabilities using a matrix mapping technique. In the special case of an isolated coherent beam-beam resonance, a stability criterion for coherent beam-beam resonances has been found in closed form. An intriguing particular concerning the effect of repeated beam-beam collisions on collider luminosity has been derived explicitly. An addition of luminosity per kick (small though, of the order of the beam-beam parameter) in the course of successive beam-beam collisions could be achieved.
Copyright (c) 2025 STEPHAN Tzenov https://creativecommons.org/licenses/by/4.0
Optimization of Argon Plasma Working Pressure through Parallel PIC Simulations for Enhancement of Material Surface Treatment
In this study, a novel method for simulating plasma dynamics using parallel programming has been developed. The equations based on Particle-in-Cell (PIC) method were utilized and adapted for this purpose. We utilized 35 processors from Sharif High Performance Computing (HPC) center and divided the plasma volume into 35 parts, with each part's PIC equation solved on a separate processor. Once the computations were completed, the results from all processors were combined to form a complete plasma volume. The simulations revealed that there is an optimal pressure for argon, at which the ion flux onto the electrode surface is maximized. Increasing the absolute value of the electrode potential also increases this flux. Therefore, for a given potential, selecting the optimal pressure is crucial for the most effective surface modification using argon plasma. In this work, for applied voltage of -500 V, the optimum pressure was 100 mTorr.
Copyright (c) 2025 H. Barati, A. Torkaman, M. Fardmanesh https://creativecommons.org/licenses/by/4.0
Discharge structure of Ar/Cl2 inductively coupled plasma: A cyclic study of discharge conditions at fixed power
Discharge structure refers to the morphology of different plasma quantities, such as electron temperature, reaction rate, plasma potential, mass flux, net charge and species density, which are determined by plasma transport mechanism and chemical processes. This morphology is rather difficult to refine in complex electronegative plasma for it is contained in a multiple-physics-field coupled system. Regarding this difficulty, the combination of self-consistent simulation, theory analysis and experimental diagnostic of this system is needed. In the scope of present article, the fluid simulation and analytic theory are utilized to investigate the Ar/Cl2 inductively coupled plasma, via a cyclic tuning of discharge pressure and feedstock gas content parameters at fixing the power. Classic discharge structure, e.g., delta, parabola, flat-top, and hollow, and specific discharge mechanisms. e.g., self-coagulation, physics coagulation, de-coagulation, grouping behavior, and the ambi-polar diffusion of mediately electronegative plasma that is tolerant to the self-coagulation, are revealed. Besides, the two types of discharge stratification, i.e., space and species, are presented. Many non-neutralities are generated during the transport process of electronegative plasma when it gives rise to the discharge structure, which are summed and analyzed for better understanding the electronegative plasmas.
Discharge structure, species and space stratification, self-coagulation
Copyright (c) 2025 Shuxia Zhao, Yu Tian https://creativecommons.org/licenses/by/4.0
H-driven degradation of PFAS in the gas/liquid interface using electrochemistry configuration of cold plasma
Plasma water treatment has emerged as a powerful technology capable of abate perfluoroalkyl substances (PFAS) in water matrices. With the electrochemical configuration and cathodic polarity, the electrified plasma/liquid interface (EPLI) not only produces in-situ hydrated electrons ( ) that readily react with PFAS, but also produced radicals in the plasma effluent. This study uses chemical reaction networks (CRN) to investigate the chemical pathways of PFAS degradation by EPLI-induced , allowing for a direct comparison with the bench experiments of Stratton et al. (Environ. Sci. Technol. 2017, 51, 3, 1643) and Alam et al. (Chemical Engineering Journal, 2024, 489, 151349). The computational results indicate that Perfluorooctanoic Acid (PFOA) degradation by EPLI-induced has a Faradaic efficiency of less than 0.01% given the typically low concentration of PFOA in water matrices, meaning that the majority of engages with water reduction, generating gaseous hydrogen. EPLI-induced alone cannot account for the energy efficiency observed in bench experiment of Stratton et al. and Alam et al., suggesting the presence of other plasma-induced radicals. This work evaluates the gas-phase H radical as crucial for degrading PFOA at the gas/liquid interface, which is created by the plasma effluent in contact with the water matrix. This work paves the way for construct effective plasma-based industrial reactors to degrade PFAS, suggesting the formation of radical-H in the plasma effluent as a key parameter to be optimized.
Copyright (c) 2025 Andressa Mota-Lima https://creativecommons.org/licenses/by/4.0
First optimization steps for the Nanocluster Synthesis of Platinum-Yttrium Alloys: Insights from a sputter gas aggregation source
Nanoclusters (NCs) are critical in advanced technologies due to their unique size-dependent properties, offering significant potential in catalysis, energy storage, energy conversion and electronic devices. In this study, the first steps were taken towards optimizing the synthesis of nanoclusters from platinum-yttrium alloys for cost-efficient fuel cell technologies, employing a magnetron sputtering system combined with a gas aggregation source. Copper was used as a benchmark material to investigate the effects of varying gas flow rates, aggregation lengths, and coating times on cluster size. Subsequently, experiments with yttrium and platinum were conducted. NC sizes in the range of 4 to 12 nm could be synthesized. These results provide a comprehensive parameter map for NC synthesis and contribute to the further development of this kind of synthesis for sustainable fuel cell technology by reducing platinum consumption and improving catalytic efficiency.
Copyright (c) 2024 Martin Fenker, Lisa-Marie Weinhold, Joachim Albrecht, Holger Kaßner https://creativecommons.org/licenses/by/4.0
Nonlinear Cnoidal Waves and Formation of Patterns and Coherent Structures in Intense Charged Particle Beams
The longitudinal dynamics of an intense high energy beam moving in a resonator cavity has been studied in some detail. Through the method of separation of variables and its obvious straightforward generalization, a solution of the Vlasov equation for the distribution function of an intense charged particle beam in the longitudinal direction has been obtained. The thus found Bernstein-Greene-Kruskal (BGK) equilibrium has been utilized to construct stationary wave patterns in the special case when the velocity distribution (energy error distribution) is Maxwellian. These are cnoidal wave patterns, showing rather intriguing and in a sense unexpected analogy between the equilibrium wave patterns in an intense charged particle beam and similar wave clusters originally observed in shallow water. Based on the hydrodynamic model, fully equivalent to the coupled nonlinear system of the Vlasov equation for the distribution function of an intense beam in the longitudinal direction and the equation for the resonator cavity potential, an amplitude equation in the most general form has been derived. A very interesting and important property of the nonlinear amplitude equation is the fact that it is of hyperbolic type (nonlinear wave equation with complex coefficients) in the entire interval of admissible values for the wave number except for a single critical point, in which it is of parabolic type (non-linear Schrodinger equation with complex coefficients).
BGK Equilibria, Cnoidal Waves, Nonlinear Evolution Equation
Copyright (c) 2024 Stephan I. Tzenov, Anton A. Volodin https://creativecommons.org/licenses/by/4.0
Technical Report: The Polomac approach to fusion energy
Deutelio is a private initiative promoting an alternative path to fusion energy. The Tokamak research line pursued worldwide since 1970 met several difficulties, heavily jeopardising the objective of commercial energy production from fusion before 2050, as a support to the global effort towards Net Zero Emissions. As a result, new plasma magnetic confinement concepts, such as Stellarators or overlooked alternatives like the poloidal confinement are being pursued to achieve more efficiency and better performance. The Polomac is a poloidal magnetic configuration where the outboard magnetic lines are deviated aside together with the plasma, to open some accesses to the dipole coils located inside the plasma. These accesses, called magnetic tunnels, are used to support, feed and cool the dipole coil. They avoid the impact with plasma which led to abandon past poloidal experiments, despite their good stability and confinement efficiency. The poloidal confinement can achieve Deuterium-Tritium reactor conditions with a magnetic field 3 times weaker than the Tokamak, in steady state rather than pulsed. With the same high field as in the Tokamak the poloidal confinement can achieve Deuterium-Deuterium reaction, thus avoiding the development of the breeding blanket to produce the Tritium. This paper presents the Polomac system, explains the development strategy of Deutelio through a small prototype focused to tune and assess the magnetic tunnels, and describes the possibility of deuterium-deuterium reaction.
Copyright (c) 2024 Filippo Elio, Francesco Elio, Marco Leone, Tiziano Fulceri, Carlo Sborchia https://creativecommons.org/licenses/by/4.0
Experimental Investigation on Compact Current Non Thermal Plasma Assisted Hydrocarbon Reforming Hydrogen Rich Gas
On-board vehicle hydrogen-rich gas extraction of gasoline reforming utilizing for fuel cells and GDI-engine lean burn combustion enhancement NOx trap applications. A non-thermal plasma discharge electrode that produces a reduce current, increased voltage 15kV source arc plasma fuel reformer is designed to operate at an arc frequency of 50 Hz. The operating factors gasoline equivalence ratio between 4 and 6.and electronically control by the fuel injector and eliminating ground spark plug plasma arc generation. The plasma arc non-thermal reformer gasoline converted into gas that contains partial oxidation contains combustible gases like hydrogen (H2), CO, non-combustible gases like CO2, N2, and a small quantity of H2O. The nonthermal plasma technology alternative for on-board hydrogen vehicle applications.
Gasoline, Non thermal plasma, Spark plug, hydrogen rich gas
Copyright (c) 2024 P. Rajkumar https://creativecommons.org/licenses/by/4.0
White Paper: When will fusion energy truly become a reality?
This paper provides up-to-date insights into fusion (thermonuclear) research, detailing ongoing projects and planned devices. The document also explores alternative sources of energy, offering a comprehensive overview of the current landscape. Additionally, notable comments and observations are provided to illuminate key aspects of the discussed topics. Stay informed as we delve into the latest advancements and initiatives in the dynamic 1eld of energy research.
Copyright (c) 2024 Renato Spigler https://creativecommons.org/licenses/by/4.0
Influence of process parameters including the confining magnetic field of a plasma beam source on the deposition of N‐doped hydrogenated carbon films
Electrically conductive nitrogen‐doped hydrogenated carbon films (a‐C:H:N) were deposited using a nitrogenacetylene gas mixture by plasma‐assisted chemical vapor deposition (PACVD). A capacitively coupled plasma beam source was used for the depositions. The plasma is excited by a radio‐frequency (RF) discharge and confined by Helmholtz magnetic coils, resulting in an increase in plasma density. The ion energy, as well as the deposition rate, can be controlled by the choice of the size of the coupling electrode, i.e. the ratio of cathode-to‐anode area, the electric current at the Helmholtz magnet coils, the total gas pressure and the RF power. The interdependence of these process parameters on the ion energy and the deposition rate has been studied in detail in this work. Hardness and electrical resistivity were measured on the deposited a‐C:H:N films.
On the significance of the external circuit, Langmuir and Bohm criterion for the stability of plasma fireballs
This paper is devoted to studying the influence of the external circuit as well as the Langmuir and Bohm criterion on the stability of plasma fireballs. A simple mathematical model is suggested that describes why plasma fireballs can get unstable up to the point where they start pulsating. The predictions of this model are compared to measured experimental data. Furthermore, it is argued that the Bohm criterion in particular determines whether a stable plasma fireball can be formed. This adds to the current understanding that fireballs are preliminarily formed due to a change in the space charge in front of a positively biased electrode in surrounding plasma. It is argued that the space charge distribution near the vicinity of the anode surface might play a role but that the initial stages of fireball formation are dominantly driven by the requirement of the double layer to satisfy Bohm’s sheath criterion and Langmuir’s criterion. The same holds for a collapsing fireball. This paper shows that if the Langmuir and the Bohm criterion are not satisfied simultaneously, a fireball cannot reach a stable state and will start pulsating with a frequency that is proportional to the square root of the mass of the working gas ions.
Numerical studies of a layered lithium-boron target for laser-driven aneutronic fusion reactions
This paper explores a novel target design for laser-driven, aneutronic, proton-boron and proton-lithium fusion reactions consisting of a stack of boron and lithium foils. In contrast to a homogeneous target, this multi-layer setup provides additional fusion channels in the different materials. The composition of the layers is chosen in descending order of the fusion reactions' thresholds, facilitating the fusion of protons that penetrate further into the material despite their energy losses due to electronic and nuclear stopping power. We employ a combination of Fluka simulations and additional numerical computations to evaluate thousands of target configurations. Four different beam energy distributions are considered: two Gaussian distributions with 6~MeV and 10~MeV mean energies, respectively, a Maxwell-Boltzmann distribution and a power law distribution. We explore the production of energy in a range of layer thicknesses motivated by the proton ranges based on ionization losses. The configuration which maximizes the produced energy for each beam type is reported. The production of fusion energy ranges from hundreds to thousands of millijoules for proton bunches of $10^{15}$ having mean energies between 2-10 MeV.
Copyright (c) 2023 Johannes Gruenwald, Leonel Morejon
Derivation of a simple engineering equation for the minimum voltage of inverted fireball onset
This paper describes the derivation of a simple engineering equation to calculate the minimal necessary bias voltage for the onset of an inverted fireball. The calculation uses the electron density in the absence of an inverted fireball as well as the grid constant and the working gas species as input parameters. It will be shown that the interplay between ionsation potential, dissociation potential (for molecular working gases), as well as the electron density in the background plasma, play an important role in the necessary minimum bias on the fireball electrode. Some of the most common working gases and their relevant parameters will also be listed in this paper. This should give experimentalists and engineers a practical equation that can be used to quickly determine the most important electrical properties of the anode that is used to trap the inverted fireball. Thus, the planning and design of experimental setups or technological devices will be made much less time-consuming and, thus, more convenient.
Measurement of inverted n-hexane fireball properties with a Multipole Resonance Probe
In this paper we present for the first time the measurement of inverted fireballs in a low-pressure Ar/n-hexane plasma by using a Multipole Resonance Probe. The basic plasma parameters such as electron density, electron temperature and Debye length as well as the particle collision frequency have been obtained for different experimental settings. These measurements show that inverted fireballs that are created in chemically active plasma offer advantageous properties regarding deposition techniques. Furthermore, the influence of the plasma parameters on grid bias and changes in neutral gas pressure has been studied within this work. It is observed that the plasma density within an inverted fireball configuration can be raised by more than an order of magnitude compared to the background plasma or without biasing the grid electrode, respectively.
Copyright (c) 2022 Gerhard Eichenhofer, Moritz Oberberg, Jörg Eisenlohr, Peter Awakowicz, Johannes Grünwald
A Novel Approach for the Particle-in-Cell Modelling of Gridded Ion Engine Plume Neutralisation
The Particle-in-Cell modelling of gridded ion engine plume neutralisation has been simplified when compared to traditional methods. This results in significantly less computational resources being required. The NSTAR engine was modelled as a reference, where simulated specific impulse values were found to be 5% higher than the real engine. This method will be most suited to rapid prototyping and optimisation studies, where speed of simulations is an important factor.
Copyright (c) 2021 Joseff Ian Parke Sturrock
On fusion chain reactions in 11B targets for laser driven aneutronic fusion
The work presented in this letter suggests that it is possible to enhance the yield in laser driven aneutronic fusion devices by fusion chain reactions. This mechanism will be described using the example of aneutronic fusion between an incoming high-energy proton beam and a 11B target. Such fusion reactions create alphas that can again fuse with a 11B particle in a dense solid state target. An improved target design will be shown that enhances the recycling of fast alpha particles that are created from fusion reactions. It will also be argued that such alpha recycling may have already been observed in experiments, although it was attributed to another, more complex physical mechanism.
Surface Treatment of Handmade Lokta Paper by Atmospheric Pressure Dielectric Barrier Discharge Using 50 Hz Line Frequency
The discharge was generated between two rectangular parallel-plate copper electrodes using a sinusoidal voltage of 12.8 kV (rms) of frequency 50 Hz and characterized using electrical and optical measurements. The effects of the discharge on the wicking property and weight loss of Lokta paper were studied respectively by the wicking test and gravimetric method. The estimated value of electron density and electron temperature in the discharge were 8.47×108 cm-3 and 1.29 eV. The results showed a significant improvement in water absorption ability and considerable weight loss (%) in Lokta paper after the plasma treatment.
Copyright (c) 2021 Rajesh Prakash Guragain, Mr., Ganesh Kuwar Chhetri, Mr., Ujjwal Man Joshi, Associate Professor Dr., Deepak Prasad Subedi, Professor Dr.
Sheaths and Double Layers with Instabilities
The properties of sheaths and associated potential structures and instabilities cover a broad field which even a review cannot cover everything. Thus, the focus will be on about a dozen examples, describe their observations and focus on the basic physical explanations for the effects, while further details are found in the references. Due to familiarity the review focuses mainly on the authors work but compared and referenced related work. The topics start with a high frequency oscillations near the electron plasma frequency. Low frequency instabilities also occur at the ion plasma frequency. The injection of ions into an electron-rich sheath widens the sheath and forms a double layer. Likewise, the injection of electrons into an ion rich sheath widens and establishes a double layer which occurs in free plasma injection into vacuum. The sheath widens and forms a double layer by ionization in an electron rich sheath. When particle fluxes in "fireballs" gets out of balance the double layer performs relaxation instabilities which has been studied extensively. Fireballs inside spherical electrodes create a new instability due to the transit time of trapped electrons. On cylindrical and spherical electrodes the electron rich sheath rotates in magnetized plasmas. Electrons rotate due to $\mathbf E \times \mathbf B_0$ which excites electron drift waves with azimuthal eigenmodes. Conversely a permanent magnetic dipole has been used as a negative electrode. The impact of energetic ions produces secondary electron emission, forming a ring of plasma around the magnetic equator. Such "magnetrons" are subject to various instabilities. Finally, the current to a positively biased electrode in a uniformly magnetized plasma is unstable to relaxation oscillations, which shows an example of global effects. The sheath at the electrode raises the potential in the flux tube of the electrode thereby creating a radial sheath which moves unmagnetized ions radially. The ion motion creates a density perturbation which affects the electrode current. If the electrode draws large currents the current disruptions create large inductive voltages on the electrode, which again produce double layers. This phenomenon has been seen in reconnection currents. Many examples of sheath properties will be explained. Although the focus is on the physics some examples of applications will be suggested such as neutral gas heating and accelerating, sputtering of plasma magnetrons and rf oscillators.
Copyright (c) 2021 Reiner L Stenzel, Johannes Grünwald, Codrina Ionita, Roman Schrittwieser, Manuel Urrutia
Letter from the editor for the first issue of JTSP
Simulation of a high proton temperature plasma toroidal magnetic trap to be used in proton-11B fusion
Several tokamaks structures containing 500 keV protons to be used in P-B11 fusion were simulated. In order to find the optimal confinement configuration, the simulation was helped by an evolutionary algorithm running 145,000 simulations. The results are presented in this paper. According to the simulations the tokamak structure can be operated to reach ignition using the proposed plasma mode that includes the use of low electron temperature and high thermal energy protons in the plasma (500 keV).
Copyright (c) 2019 Javier Lopez Segura, Nicolas Urgoiti Moinot
Utilisation of plasma centrifuges for life support systems on Mars
In this paper the possibility of utilising a plasma centrifuge for oxygen generation in outer space is discussed. It is proposed that a plasma centrifuge can not only create oxygen for human consumption very efficiently but is also able to produce useful by-products. Special emphasis is given to life support systems working in the atmosphere of Mars, where oxygen and carbon raw materials can be obtained directly from the atmosphere. The system under consideration in this work is a plasma centrifuge with axial circulation that contains a fully ionised plasma. Under these conditions the carbon dioxide from the Mars atmosphere will be entirely dissociated. Thus, the atomic oxygen and carbon can easily be separated.
Temperature influence on the diethylamine sensing abilities of CuO nanoparticles deposited by atmospheric pressure plasma
In this work we present a copper oxide nanostructured analysed as a gas sensor but the focus of the paper is on the temperature dependance of the sensor sensing properties. As a case study temperature dependent diethylamine sensing is presented. The CuO nano flakes were deposited and evenly distributed on intercalated electrodes by an atmospheric pressure plasma source. The sensor was electrically connected to ohmmetre and inserted in an oven chamber where it was isolated from atmosphere and heated to desired tempearuteres. The intrinsic resistnace of the sensor was measured in dependence of the temperature and the temperature change rate. Then the possibility to detect diethylamine was investigated and the sensor response studied. Finally, the temperature dependence of the detection of the amine was explored. It was possible to demonstrate reliable sensing of the amine down to temperatures of 100 °C and below.
Copyright (c) 2020 Gregor Filipič, Johannes Gruenwald, Dr.
Characterization Of Dielectric Barrier Discharge (DBD) Produced In Air At Atmospheric Pressure And Its Application In Surface Modification Of High-Density Polyethylene (HDPE)
The low surface energy of HDPE limits its industrial uses as it is not suitable for printing and adhesion. The main aim of this work is to improve the wetting properties of high-density polyethylene (HDPE) using air dielectric barrier discharge (DBD) operating at the line frequency (50 Hz). The estimation of electron temperature and electron density has been done by electrical and optical methods. The surface roughness of the control and plasma treated polymer film is analysed by contact angle (CA) measurement, surface energy measurement and scanning electron microscope (SEM) analysis. The contact angle was found to be suppressed from 93.180±2.00 to 63.750±0.880 after 10s of plasma treatment which implied that the surface property had changed to a hydrophilic state caused by an increase in the surface roughness.
Copyright (c) 2020 Rajesh Prakash Guragain
Spectroscopic diagnostics of a high-frequency dielectric barrier discharge of atmospheric pressure in mixtures of cadmium diiodide vapor with neon and small additions of xenon
Diagnostics of the emission spectra of a gas-discharge plasma of a barrier discharge of atmospheric pressure in mixtures of cadmium diiodide vapor with neon and small additions of xenon is carried out. A gas-discharge plasma was created and the components of the working mixture were excited by a high-frequency barrier discharge at a sinusoidal voltage pulse repetition rate of up to 140 kHz. Emission of exciplex molecules of cadmium monoiodide with a maximum emission at a wavelength of λ = 655 nm and xenon iodide with a maximum of radiation at wavelengths λ = 253 and λ = 320 nm, excimer molecules of iodine, lines of atoms of cadmium, iodine, neon and xenon was revealed. It was found that at temperatures of the mixtures under study above 150 0C, the predominance of radiation from exciplex molecules of cadmium monoiodide is observed. The reason for the increased brightness of the emission of exciplex molecules of cadmium monoiodide in mixtures of cadmium diiodide vapor with neon and xenon additive is established. The regularities in the spectral characteristics of radiation in the mixtures under study are discussed. A high-frequency barrier discharge of atmospheric pressure in mixtures of cadmium diiodide vapor with neon and xenon is of interest for creating a multi-wavelength excilamp in the UV and visible spectral ranges
AC Magnetic sensor to measure mega-amps current and kilo-tesla magnetic fields up to gigahertz frequencies
An AC magnetic sensor is presented for measuring the high speed and high strength magnetic field generated in Z-pinch fusion machines. The proposed magnetic sensor provides the measurement of magnetic fields across a broadband frequency range. The simulation of magnetic probe is presented using a SPICE simulation software LTspice. The magnetic sensors are installed in a Pulsotron-3 Z-pinch machine and measured performance of the sensor are presented. This sensor also can be used to check the ignition conditions of the Z-Pinch by measuring the magnetic field generated by the output streams of large number of reacted alpha particles. The equations for measuring non-stationary magnetic field due to rapidly varying electric currents and a LTspice simulation file are provided to help the engineers to design, build, and install this kind of sensors.
Copyright (c) 2020 Javier Lopez Segura, Nicolas Urgoiti
Large magnetic fields and direct electric energy after P+B11 nuclear fusion measured at the Pulsotron-3 reactor
The measured results of two tests T3073 and T3074 performed in 28 August, 2020 are presented in this paper. Tests are conducted in the z-pinch type nuclear fusion reactor Pulsotron-3 with the target loaded with Hydrogen-Boron (H+B11) thermonuclear fuel. A group of Energy Recovery Coils (ERCs) were mounted to recover the electric energy directly from the plasma for the first time in the world and ERCs stored the energy in several large capacitors. During the test T3073 and T3074 the energy recovery capacitors recovered 22.59% and 17.74% of the injected energy at the target. A magnetic sensor MAG-4 consisting of inductor coils and dipoles were installed in Pulsotron-3 to measure the Time Of Flight (TOF) of the plasma and the magnetic field generated due to nuclear fusion. Magnetic fields more than 4 megateslas are obtained during the two tests. It is also observed that Pulsotron-3 with the target loaded with thermonuclear fuel generated 20-34 times larger peak magnetic fields and 12-18 times larger stabilized magnetic fields compare to the tests done using unloaded target (dummy loads). In this proposed technology Pulsotron-3 utilizes thermonuclear fuel to generate clean electric power without CO2 footprint and reduce the operational cost. This industrial approach is a promising solution that can reduce world emissions to zero in less than 8 years.
Copyright (c) 2021 Javier Lopez Segura, Arpan Pal
Self-oscillations of non-neutral plasma diode
Self-oscillations of non-neutral plasma diode operating in the anode-glow mode are analysed using the self-consistent one-dimensional Particle-in-Cell Monte Carlo collisions model. In order to obtain these states, the current exceeding the space-charge limited current has to be emitted from the cathode, the electron mean free path must be much longer than the cathode-anode gap, and the cathode voltage must be slightly larger than the ionization potential of the background gas. It is obtained that in such a case, immobile ions form the electrostatic trap for the electrons generated in the cathode-anode gap. These electrons oscillate between the cathode and the anode causing the self-oscillations of the plasma potential. It is shown that the increase of the emission current leads to the increase of the frequency of the obtained self-oscillations. Starting at some value of the emission current, a lot of the emitted electrons are got trapped in the electrostatic well, which leads to the transition to chaos.