Papers by Keyword: Plasma

Abstract: Ionic plasma thruster is advanced propulsion technology utilized for space applications. Scientific research remains focused on the development of efficient and effective thruster technologies for space exploration. The technology of ionic plasma thruster is notable for its ability to achieve high specific impulse and fuel efficiency. This study outlines our study on plasma and endeavours to enhance Ionic Plasma Thruster through the utilization of innovative methodologies and materials. The experimental setup utilizes electrodes energized by a 1000 kV power module and Lithium-Ion batteries. The design of electrodes is to enhance the concentration of flow electrons for a significant ionization, after ionization the discharged particles (ions) causes the thruster to the system. In addition to ameliorate the thruster, neodymium magnets are strategically positioned, and to expedite the movement of ions and improve the ionization processes. This paper arrays our study and development on plasma ionization and ionic plasma thruster thorough examination of our experimental configuration, methods, and initial findings. Our ongoing research and development efforts aim to expand the technology of ionic plasma thruster, with the goal of enabling more efficient, cost effective and sustainable space exploration missions.

Abstract: The Terahertz radiation generation through laser plasma interactions has attracted significant attention due to its wide range of applications in the field of spectroscopy, imaging, communications and medical. This work explores the variation of nonlinear current in the plasma which is the essential driver for Terahertz radiation generation. When intense laser pulses interact with plasma, a nonlinear ponderomotive force is generated, which leads to oscillations of plasma electrons. The oscillating electrons generate a nonlinear current, and their oscillation frequency causes the emission of Terahertz radiation. These nonlinear currents play a crucial role in exciting low-frequency electromagnetic waves in the THz regime. We analyze how the nonlinear current varies with key plasma parameters, including laser intensity, plasma density, magnetic field, and beam width. Theoretical modeling and numerical simulations demonstrate how optimizing these parameters enhances nonlinear current. Our results provide insights into controlling and optimizing nonlinear plasma currents for enhanced THz generation, offering promising advancements in plasma-based THz sources. This paper presents a theoretical model to describe the variation of nonlinear current as a function of these parameters, and investigated how laser beating can modify the plasma response for terahertz radiation generation.

Abstract: This work investigates the radiation pattern of a 5 GHz antenna composed of a metal dipole antenna and surrounded by fluorescent tubes which act as reflectors (plasma medium). The study emphasizes the role of plasma reflectors in improving the antenna’s efficiency by controlling the radiation pattern. The electrical parameters of the plasma medium are modeled by Drude model in Comsol Multyphysics for different voltage discharges. Also, a CST software is used to simulate metallic dipole antenna reconfigurability. The results show that the plasma can be used as a good reflector when its permittivity is negative () and . Moreover, it is shown that with increasing the discharge voltage, the plasma reflectivity increases, this is because the gain increases and the directivity of the antenna considerably changes. Keywords: Reflector, Plasma, COMSOL, CST, Gain, Directivity.

Abstract: Plasma and TIG arc welding they are similar welding processes for the base of plasma welding is tig welding. The main purpose of this paper to come to a detailed conclusion based on a comparative analysis of both welding processes. The analysis is done steel bars each applied with the particular welding technique either plasma or tig welding. The principles of each welding procedure are discussed on how they welding is carried out, the mechanics and the technological functions of the welding devices are also discussed. The time required to complete a weld, the amount of current used. Impact on the steel is investigated caused by each welding processes. The welded joints are tested for bending and how much they elongate when under bending stress. The welded joints are done as butt welds for both of the grouped steel bars. These welding processes are used in industries where precision is of great importance like aerospace, design of industrial machinery, ship construction and Petro chemical industries. The concluded results of this paper will be of great contribution to the manufacturing industries because they would be able to know which welding process is best for which particular case or both must be used in order to achieve an ideal outcome. Keywords: Plasma and Tungsten inert gas TIG welding arc, tensile mild Steel bars, bending, butt weld, Amount of current, elongation.

Abstract: The growing demand for advanced materials with enhanced surface properties has driven significant research into various surface modification techniques. Among these, plasma treatment emerges as a versatile and effective method for improving the characteristics of different materials [1-10]. Plasma technology offers unique benefits, such as the ability to modify surfaces without the need for harsh chemicals or excessive energy inputs. This study focuses on two specific materials: Aluminum alloy 2024, recognized for its high strength-to-weight ratio, excellent corrosion resistance, and widespread application in aerospace and automotive industries, and unvulcanized rubber compounds, which provide flexibility and resilience essential for various applications, including seals and gaskets. Utilizing dielectric barrier discharge (DCSBD) technology for surface modification presents a novel approach to activating and cleaning the surfaces of these materials [11,12]. DCSBD plasma operates at atmospheric pressure, making it a cost-effective alternative to traditional cleaning and activation methods that often rely on corrosive chemicals or mechanical abrasion. The versatility of DCSBD plasma allows for fine-tuning of various parameters, such as voltage, treatment time, and gas composition, enabling tailored modifications to achieve desired surface properties. This research aims to investigate the effects of plasma application on Aluminum alloy 2024, particularly in terms of enhancing surface energy and wettability. Increasing surface energy is critical for improving adhesion properties, particularly for applications that involve coating or bonding processes [13]. The plasma treatment process results in enhanced surface energy, significantly reducing the contact angle of testing liquids on treated surfaces compared to their untreated counterparts. This enhanced wettability can lead to improved adhesive bonding and overall performance of coated or bonded materials [14-17]. The study evaluates how variations in treatment parameters such as voltage, exposure time, and airflow rate affect the surface properties of both materials. Furthermore, the impact of varying distances between the plasma source and the treated surfaces is examined, as this distance significantly influences the efficacy of the surface modification process. Understanding the relationship between these variables is essential for optimizing plasma treatment conditions. Previous studies have highlighted the potential of plasma treatment to improve the adhesion of coatings to Aluminum alloy 2024 [18-20]. This research asserts that atmospheric pressure plasmas provide a compelling alternative to conventional surface preparation techniques, such as acid etching or mechanical abrasion, which can be harmful to both the environment and the materials being treated. Moreover, the comparative surface modification effects on the two distinct materials: shape-stable Aluminum alloy 2024 and shape-unstable unvulcanized rubber offer valuable insights into the plasma treatment process. The findings from this research are expected to elucidate the intricate relationship between plasma treatment parameters and the resulting surface characteristics. By systematically varying the distance between the plasma source and the material surfaces, this study aims to identify optimal conditions for effective surface modification. Ultimately, this research contributes to a better understanding of plasma technology's capabilities, paving the way for enhanced applications across various industries. Experimental data suggest that the plasma process significantly reduces contaminants and enhances the alloy’s wettability. Another study examined how plasma treatment can improve the adhesion of paint films by pre-treating Aluminum 2024 surfaces. To improve adhesive bonding on Aluminum 2024, further research demonstrated that atmospheric-pressure plasmas offer a viable alternative to acid treatments or abrasive techniques for preparing surfaces before bonding [18]. Exposure times for Aluminum 2024 surfaces differ based on the plasma-generating device; one study applied exposure times from 1 to 10 seconds at 330 [W] using a DCSBD system [21]. Another essential factor in plasma-based surface modification is the material-to-plasma distance, as seen in research where wood surfaces were exposed to plasma for 10 seconds with spacers to control the separation distance at 0.15 [mm], 0.45 [mm], and 1 [mm] [22]. Comparable studies using DCSBD plasma technology at 400 W applied exposure times from 5 to 60 seconds, under varying atmospheric gases such as O₂, CO₂, N₂, and Ar, with separation distances from 0.1 to 0.2 [mm] [23]. This work aims to investigate the potential of DCSBD plasma to treat flat materials, specifically Aluminum 2024 alloy and unvulcanized rubber compound (UnRB). The study seeks to compare plasma’s surface modification effects on shape-stable (AA2024) and shape-unstable (UnRB) flat materials. Prior studies have shown that adjusting the distance between the plasma source and the surface significantly impacts surface energy and cleanliness. Here, we focus on evaluating how distance influences the effectiveness of plasma surface modification on AA2024 and UnRB, aiming to determine the maximum distance at which effective surface modification can be achieved. Evidence of plasma efficacy includes a notable increase in surface energy and fluorescence changes, clear indicators of the plasma’s cleaning effect. Given that UnRB is less dimensionally stable than aluminum alloy, comparing these materials at varying distances from the plasma source offers fresh insights into how different surfaces respond to plasma treatment. The findings simulate conditions where materials are at various distances from the plasma-generating ceramic dielectric, providing deeper understanding of plasma’s cleaning and energy effects on different surface types.

Abstract: Transparent conducting glass is a crucial layer of Dye Synthesized Solar Cell (DSSC), due to it allows sunlight penetrating to the solar cell. DSSC has a low efficiency until semiconductor Titanium Dioxide (TiO2) was employed as the anode material. TiO2 has a high photosensitivity, high structure, stability under solar irradiation and in solution, and low cost. In this study TiO2 was deposited on the conductive glass using microwave plasma method. Plasma was generated using electromagnetic wave from microwave magnetron. TiO2 powder was dissolved using pure water and ethanol at different concentration. The coating process was conducted on a 2.5 x 2.5 cm of a conductive glass, and the effect of plasma generation time was observed at 0.5, 1, 2, 3, and 5 minutes. The thickness, roughness, and microstructure of TiO2 coating on the conductive glass was observed using 3D measuring laser OLS4100. The result shows that the fabrication of TiO2 coatings using microwave plasma is feasible. The concentration of solution and plasma generation time plays an important role to the thickness, roughness, and microstructure of TiO2 coatings. An optimum result was obtained at plasma generation time of 0.5 minute with 12.49 μm and 3.398 μm of thickness and roughness respectively using 10 g TiO2 + 50 ml ethanol and 40 ml H2O.

Abstract: The carbon vacancy (V_C) is a lifetime-killer defect that hinders the correct functionality of 4H-SiC bipolar devices. Until now, different methods based on carbon interstitial injection, have been proposed, in order to reduce its concentration. However, if on one hand these methods effectively reduce the V_C concentration in the epilayer, on the other they cannot prevent the re-generation of V_C occurring during the manufacture of a p-i-n diode, e.g., p+ implantation and activation. In the following contribution, we employ PIII of B for the formation of the anode for a p-i-n diode. We show that by PIII, it is possible to simultaneously form a p⁺n junction with a low concentration of V_C in the drift layer.

Abstract: Bilayer graphene has been widely studied in recent years due to its intriguing physical properties and potential engineering applications. Here, we report on the stability measurements of isotope-labeled bilayer graphene with different stacking sequences. The results showed evidence of different defect intensity after the Ar plasma treatment. We found that the AB stacked bilayer graphene shows better stability when compared to twisted bilayer and monolayer graphene. However, for the protection of the under layer graphene, the twisted bilayer graphene showed better results. Our work demonstrates that the stability of bilayer graphene strongly depends on the layer stacking sequence.

Abstract: The work is devoted to the basics of surface modification of structural materials for the effective protection of machine parts and mechanisms operated in extreme conditions from the mechanical impact of aggressive media, by the method of plasma-chemical exposure to concentrated streams of matter and energy by means of plasma generators, which allow for surface renovation and engineering.

Abstract: Surface modification with plasma has been widely applied to polymeric materials. This treatment is intended to improve the surface properties of the polymer including its wettability and adhesiveness. The aim of this paper is to provide a review of the literature on the surface treatment of polymers with plasma, which focuses on the effects of adhesive and surface tribology properties. The related surface properties are also reviewed in order to strengthen the review of adhesive properties and tribology. Various types of plasma treatments that have been reviewed reported that plasma can be effectively used to improve surface properties, especially adhesive and tribological properties. On a small surface treatment has been developed plasma jet treatment which has been widely applied in biomedical applications.