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A generalized inductively coupled plasma (ICP) efficiency model is derived, which may be used to predict plasma generation efficiency with many types of radio frequency (RF) electric propulsion system. The analytical ICP discharge model is used to examine device scaling, and investigate trends in ICP performance as a function of geometry and system inputs. The ICP efficiency model is applied to an analytical RF cathode model to predict device behavior. Results from the updated RF cathode model show improvements in agreement with experimental data. [ABSTRACT FROM AUTHOR]

All human beings need healthy nutrition to grow, so the lack or excess of low-amount elements causes diseases in humans, for this reason, it is essential to know the presence of elements in food. Arak aluminum production factory is located next to Chogha village, so it is necessary to study the effects of this factory and other industries in the region on its agricultural products. In this study, the content of 11 elements was determined: aluminum, bromine, calcium, chlorine, iron, magnesium, manganese, potassium, sodium, scandium, and zinc in crops as wheat, barley, peas, beans and alfalfa prepared from the village of Chogha in the Arak region by neutron activation analysis, as well as 3 other elements, including arsenic, lead, and cadmium were determined by inductively coupled plasma analysis. Magnesium concentration from 1310 to 3970, manganese from 15.2 to 66.3, sodium from 14.2 to 1490, aluminum from 5.72 to 914, chlorine from 364 to 12000, calcium from 413 to 29600, bromine from 0.23 to 14.50, potassium from 4740 to 14700, iron from 10.1 to 1310.0, scandium from 0.033 to 4.02, zinc from 27.7 to 96.7, arsenic from 0.000 to 0.021, lead from 0.000 to 0.003 and cadmium from 0.00 to 0.02 mg/kg. The results show that the concentration of chlorine, manganese, magnesium, iron, sodium, aluminum, bromine, calcium, scandium, zinc, and lead in alfalfa, the concentration of potassium in pinto beans, the concentration of cadmium in barley, and the concentration of arsenic in wheat are higher than another analyzed sample.

This research examines the impact of the coefficient of secondary electron emission (SEE) on various discharge features of plasma to improve the performance of deposited thin films. Unlike previous studies, we employed two-dimensional numerical modeling (2D) of an ICP reactor at a radiofrequency of 13.56 MHz and a low pressure of 1 Torr, using a finite element approach. This detailed investigation into parameters such as ionization rate, electric field, electron temperature, and electron density provides new insights into plasma interactions. Our findings reveal a significant correlation between the SEE coefficient and key plasma attributes. Notably, increased secondary electrons lead to a substantial rise in electron density and a reduction in sheath thickness, indicating an impactful change in the spatial distribution of plasma particles. Additionally, electron temperature increases exclusively in sheath regions, a novel observation not reported in earlier studies. Furthermore, higher SEE coefficients correlate with increased ionization rates within each sheath, suggesting a crucial role in maintaining discharge processes. This comprehensive analysis uncovers complex interdependencies within the plasma discharge system, offering valuable advancements for thin film deposition techniques.

Ultrafine semiconductor fabrication by lithography has undergone a significant transition from deep ultraviolet (DUV) to extreme ultraviolet (EUV) processes, which presents new challenges. Specifically, the damage caused to components utilized in an EUV system, such as multilayer mirrors, reticles, and pellicles within lithography equipment, owing to EUV-induced H2 plasma, is a critical issue that directly affects the process yield and equipment lifespan. To address these issues, it is crucial to establish an environment similar to that of EUV-induced plasma and develop a method to evaluate the resulting damage. Accordingly, an evaluation method is developed for assessing the material damage caused by hydrogen radicals and ions in inductively coupled H2 plasma. In these systems, the electron density ranged from 5 × 108 to 3.5 × 1010 cm−3, the electron temperature ranged from 1 to 4 eV, and the ion energy ranged from several to tens of eV; these conditions closely align with the environment of an EUV-induced H2 plasma. The damage to Mo2C, a potential EUV pellicle material, is quantitatively analyzed by measuring the fraction of the pore area and examining the chemical characteristics after exposing the samples to various plasma conditions, including electron density, gas pressure, and exposure time. [ABSTRACT FROM AUTHOR]

This article analyzes the approaches to macro- and mesoscale computational modeling of the dynamics of metal powder particles motion in the condensation chamber of a plasma reactor, spheroidization, coagulation, and phase transitions in particles. The features of different regimes of vaporization and condensation were described. The influence of phenomena such as Brownian motion and thermophoresis on the process was explored. The parameters of the process at which the formation of core-shell particles occurs were determined. The model can be used to optimize and select the effective regimes for the processing and synthesis of powder materials in inductively coupled plasma.

The effect of plasma activation of reactive gas on the process of reactive magnetron synthesis of oxide coatings was theoretically and experimentally investigated using a radio-frequency inductively coupled plasma source, which creates a flow of activated reactive gas directed towards the surface on which the oxide coating is deposited. The reactive gas passes through a dense inductively coupled plasma located inside the plasma source, while argon is supplied through a separate channel near the magnetron. A theoretical model has been built allowing the calculation of spatial distributions of fluxes of metal atoms and molecules of activated reaction gas, as well as the stoichiometry area of the synthesized coatings. Calculations were performed on the example of aluminum oxide. It was found that the plasma activation of the reactive gas allows to increase the sticking coefficient of oxygen to the surface of the growing coating from values less than 0.1 for non-activated molecular oxygen to 0.9 when 500 W of RF power is introduced into the inductive discharge. In order to verify the developed model, experiments were conducted on depositing an aluminum oxide film on glass substrates located at different distances from the magnetron target, followed by measuring the distribution of film transparency along the substrate length and comparing it with the calculated distribution. A comparison of the calculation results with the experimental data shows a good agreement in the entire studied range of parameters. Based on the generalization of the obtained results, an empirical rule was formulated that the power ratio of the magnetron discharge and the plasma activator should be approximately 8:1.

A developed technological reactor for the formation of a diamond-like carbon coating on substrates up to 200 mm in diameter by chemical vapor deposition in high-density inductively coupled plasma at an operating pressure below 5 Pa is described. The results of experimental studies on obtaining a diamond-like carbon coating in the developed reactor are presented. The dependences of the rate of deposition of a diamond-like carbon coating on the power of the RF discharge, the operating pressure, and the consumption of the film-forming gaseous reagent have been established. Also, for the developed technological reactor, the modes for obtaining diamond-like carbon coatings with the best mechanical properties were established with the following process parameters: RF power 600–900 W, precursor gas flow rate 15–50 cm3/min, the ratio of plasma-forming gas volumes to film-forming gas volume 3:1 at a residual pressure in the working chamber of not more than 4 Pa. It has been shown by Raman spectroscopy that the coatings obtained under efficient conditions contain a significant amount of a diamond-like phase.

A multielement inductively coupled plasma atomic emission spectrometry (ICP-AES) technique has been proposed for high-speed monitoring of the preparation of pure antimony, and analytical lines of analytes with the weakest spectral effects have been chosen. We have studied the effect of matrix component concentration (5 to 40 g/L) on the analytical signals of impurity elements. Changes in excitation conditions in the plasma at a varied antimony concentration in solution and varied ICP power have been assessed using the ICP robustness. The robustness was evaluated from the intensity ratio of the magnesium ionic and atomic lines. The presence of 40 g/L of antimony in solution has been shown to reduce the ICP robustness by up to 5%. The adequacy of the proposed technique has been confirmed by the standard addition method and comparison with results obtained by an independent method. The proposed technique for analysis of antimony allows one to determine 56 impurity elements with detection limits from n × 10–7 to n × 10–4 wt %. [ABSTRACT FROM AUTHOR]

Agriculture has high requirements for both the quality and quantity of water resources. However, the traditional monitoring methods used in the field of water quality monitoring for agricultural irrigation suffer from issues such as complex operation, low automation, and low efficiency. To address these problems, this study proposes an agricultural irrigation water quality monitoring system based on an inductively coupled plasma optical emission spectrometer and designs the usage process and strategies of the spectrometer according to the characteristics of agricultural irrigation water. The water quality monitoring system can precisely monitor heavy metal elements that may contaminate agricultural irrigation water and eliminate the interference of other impurities. Experimental results show that the system achieves a correlation above 0.999 for the standard curves of five major heavy metal elements, and the signal-to-noise ratio of heavy metal elements reaches 12.56 when the system carrier gas flow rate is 0.8 L/min. Compared to traditional detection methods, the system exhibits higher detection speed, automation, and comparable accuracy, thus demonstrating potential for practical application in the field of water quality monitoring for agricultural irrigation. [ABSTRACT FROM AUTHOR]

The generation of a low-frequency low-pressure inductive discharge with ferromagnetic enhancement of the magnetic coupling between the coil and the plasma is investigated. The main features and advantages of this plasma generation method for surface processing technologies are considered. New experimental data on the electrophysical and dynamic characteristics of ferromagnetic-enhanced low-pressure inductive discharge in argon with the addition of oxygen are presented. It is shown that the radial distribution of plasma parameters in a gas-discharge chamber can be controlled using distributed discharge generation. Significant fluctuations in the electron temperature during the discharge electric field period are found, and the mechanism of their occurrence is analyzed. [ABSTRACT FROM AUTHOR]

For decades, the Buriganga River in Dhaka, Bangladesh, has suffered from persistent pollution, leading to heavy metal contamination in fish samples that poses significant risks to human health. This study conducted an analysis of the whole bodies of various fish species, including Heteropnuestes fossilis, Channa punctatus, Notopterus notopterus Channa striata and Colisa fasciata to examine the concentrations of Chromium, Manganese, Nickel, Copper, Zinc, Arsenic, Cadmium, Barium, and Lead. The analysis was performed using inductively coupled plasma mass spectrometry, revealing notable concentrations of Pb, Ni, Cd, and Zn, with average levels of 6.85, 156.77, 0.41, and 3.37 mg/kg, respectively.Assessment of target hazard quotients for Pb, against recommended benchmark doses of observable effects, indicated levels 2 to 6 times higher than the recommended safety thresholds. The cumulative totals of target hazard quotients across multiple specimens exceeded 2 and, in some cases, reached up to 7, surpassing the safety cutoff of 1. The risk of cancer from Ni and Pb was calculated to be 1 in 10,000 on average for each, classifying it as a moderate risk. Quantitative analysis revealed that heavy metal concentrations of Pb, Ni, Cd, and Zn in most fish samples exceeded reference safety values.Simultaneously, hazard analysis identified critical concerns regarding Pb content in one sample, and cumulative toxin loads in almost every sample were deemed unsafe for regular consumption. In addition to quantitative assessments, a qualitative survey employed observation techniques, focus group discussions, and key informant interviews to investigate consumption behaviors and viewpoints on fish contamination. The results revealed that consumers generally held an enthusiastic attitude towards consuming these fish and were largely unaware of the associated health hazards.

A graphitic digestion method linked with inductive coupled plasma optical emission spectroscopy (ICP OES) instrument was used to determine the levels of trace elements in frozen and chilled chicken samples collected from markets in Jouf city, Saudi Arabia. The current method is innovative because samples are digested using a graphitic digestion system, which is safer, facile sample handling, short time for assessment, and more environmentally friendly than existing procedures. The results revealed that the chilled chicken samples contained higher concentrations of Na, Fe, Cr, and Mn than the frozen samples, which were below detection limit. Furthermore, the Cu, Al, Zn, and Cr contents in some of the analyzed chicken samples were over the maximum permissible limit of international standards, indicating a serious risk to consumers. The estimation of health-risk indicated that trace metal contamination causes health risks to the consumers, but the effect decreases with decreasing the target hazard quotient value in the rank of Cr > Al > Zn > Cu > Mn > Fe, with all values less than 1 except for Cr in chilled chicken. Moreover, the tolerable limit (1 × 10−6) for the carcinogenic risk for Cr in chilled chicken was observed to be exceeded.

Lung cancer (LC) is the leading cause of cancer deaths, and chronic obstructive pulmonary disease (COPD) can increase LC risk. Metallomics may provide insights into both of these tobacco-related diseases and their shared etiology. We conducted an observational study of 191 human serum samples, including those of healthy controls, LC patients, COPD patients, and patients with both COPD and LC. We found 18 elements (V, Al, As, Mn, Co, Cu, Zn, Cd, Se, W, Mo, Sb, Pb, Tl, Cr, Mg, Ni, and U) in these samples. In addition, we evaluated the elemental profiles of COPD cases of varying severity. The ratios and associations between the elements were also studied as possible signatures of the diseases. COPD severity and LC have a significant impact on the elemental composition of human serum. The severity of COPD was found to reduce the serum concentrations of As, Cd, and Tl and increased the serum concentrations of Mn and Sb compared with healthy control samples, while LC was found to increase Al, As, Mn, and Pb concentrations. This study provides new insights into the effects of LC and COPD on the human serum elemental profile that will pave the way for the potential use of elements as biomarkers for diagnosis and prognosis. It also sheds light on the potential link between the two diseases, i.e., the evolution of COPD to LC. [ABSTRACT FROM AUTHOR]

Ion thrusters have acquired extensive applications in the space industry with their advantages of high efficiency, high specific impulse, and long lifetime. To operate a radio-frequency (RF) ion thruster successfully, a high-frequency current must be generated to facilitate the discharge of inductively coupled plasma. In this study, with support of trial and error, it is discovered that the thrust performance of an RF ion thruster depends on not only the RF power but also on other critical parameters, such as the propellant flow rate, ion grids voltages, and RF input power. A surrogate model, namely – the Kriging model, is employed to simplify the estimation and optimization of thrust performance. The thrust and specific impulse are selected to be the crucial metrics for used Kriging models for categorizing all types of propulsions. On the basis of Kriging model simulations, the designed RF ion thruster can achieve a thrust of 1.9 mN, a specific impulse of 1649.5 s, and a thrust efficiency of 48% under a propellant flow rate of 4 sccm, grids' voltage difference of 2500 V, and an RF input power of 40 W. • Kriging model was to simplify the optimization of radio-frequency ion thrust performance. • Thrust performance of RIT depends on the radio-frequency power and other parameters. • The optimal RIT can achieve a thrust of 1.9 mN and a specific impulse of 1649.5 s. • The resulting thrust efficiency fulfills 48% under a propellant flow rate of 4 sccm. [ABSTRACT FROM AUTHOR]

A novel dual-antenna micro plasma thruster (DMPT) driven by radio-frequency (rf) power supply is proposed and characterized experimentally. The Langmuir probe (LP) and the retarding potential analyzer (RPA) are applied to measure the plasma parameters. The results show that compared to the single-antenna, the dual-antenna yields higher electron density, electron temperature, and ion energy. The measurements from the rf I–V probe indicate that the power coupling efficiency for the dual-antenna is about 2.6 times higher than that for the single-antenna. The plasma potential drop in the plume of the DMPT is the reason for the formation of ion beam. The neutral gas temperature is measured by rovibrational ban matching of the first negative band system of ionic nitrogen (N 2 +) for operating powers of 20 W up to 100 W. The total thrust of the DMPT has been calculated by the sum of the ion thrust and the neutral gas thrust. The total thrust at 100 sccm argon flow rate and 100 W rf power is ∼2.23 mN, which indicates an up to 168% thrust gain compared to the cold gas thrust, and a significant 11% total thrust is attributed to the ions' electrostatic acceleration. The specific impulse and thruster efficiency at the above experimental conditions are ∼76 s and ∼0.8%, respectively. These initial results show that the dual-antenna scheme has better performance and is more promising than the traditional single-antenna design for electrodeless micro-electric propulsion. This novel and efficient micro plasma thruster is particularly useful for cubic satellites and scientific experiments in space (such as gravitational wave detection) which require gesture and orbit control of great precision. • The dual-antenna scheme can generate higher plasma density and electron temperature. • The significant phenomenon of higher energy ions was observed in DMPT. • Higher power coupling efficiency in DMPT than that in SMPT. [ABSTRACT FROM AUTHOR]

Regularities of the reflected signal intensity changing in time, recorded by the detector of the laser interferometer with the operating frequency of 670 nm during the inductively coupled plasma reactive ion etching in a Cl2/N2/O2 atmosphere of GaN, p-GaN and AlGaN in AlGaN/GaN and p-GaN/AlGaN/GaN heterostructures has been established by laser interferometry and scanning electron microscopy methods due to the changes in refractive indices and etching rates. During inductively coupled plasma reactive ion etching of GaN and p-GaN layers, the intensity of the reflected signal changes according to a periodic law with the thickness change period of about 144 nm, and for AlGaN layers about 148 nm, which is due to differences in their refractive indices and etching rates. During the crossing of the p-GaN/AlGaN and AlGaN/GaN interface, there is an abrupt change in the intensity of the reflected signal within 2.7–9.5 % for 20–40 s, due to changes in the aluminum concentration, refractive indices, and etching rate at the interfaces. The change in the periodicity of the interferogram, which is accompanied by a jump in intensity when passing through the etching front through the p-GaN/AlGaN and AlGaN/GaN interface, makes it possible to determine the end time of the inductively coupled plasma reactive ion etching of the AlGaN and p-GaN layers using laser interferometry in real time in AlGaN/GaN and p-GaN/AlGaN/GaN heterostructures with two-dimensional electron gas. The obtained results can be used to form microwave and power electronics devices elements which are based on the AlGaN/GaN heterostructures.

Hybrid plasmas have been reported in various areas of research over the last 40 years. However, a general overview of hybrid plasmas has never been presented or reported. In the present work, a survey of the literature and patents is carried out to provide the reader with a broad view of hybrid plasmas. The term refers to several different configurations of plasmas, including but not limited to: plasmas driven by several power sources simultaneously or sequentially, plasmas that have the properties of both thermal and nonthermal plasmas, plasmas that are enhanced by additional energy, and plasmas that are operated in a unique medium. In addition, a way of evaluating hybrid plasmas in terms of the improvement of processes is discussed, as well as the negative impacts that follow the employment of hybrid plasmas. Regardless of what the hybrid plasma in question is composed of, it often poses a unique advantage to its nonhybrid counterpart, whether it be used for welding, surface treatment, materials synthesis, coating deposition, gas phase reactions, or medicine. [ABSTRACT FROM AUTHOR]

This work reports on the (zero-dimensional) global model study of argon plasma chemistry for a cylindrical thruster based on inductively coupled plasma (ICP) whose output has a system of two grids polarized with each other with direct current potential. The global model developed is based on particle and energy balance equations, where the latter considers both charged and neutral species. Thus, the model allows the determination of the neutral gas temperature. Finally, this study also investigated the role of excited species in plasma chemistry especially in the ions production and its implications for propulsion parameters, such as thrust. For this, the study was carried out in two different scenarios: (1) one taking into account the metastable species Arr and Arp (multi-step ionization), and (2) the other without these species (single-step ionization). Results indicates a distinct behavior of electron temperature with radiofrequency (RF) power for the investigated cases. On the other hand, the gas temperature is almost the same for investigated power range of up to 900 W. Concern propulsion analysis, a thrust of 40 mN at 450 W was verified for case (1), which represents a remarkable thrust value for electric thrusters.

A method is proposed for the analysis of trace element concentrates by a thin layer method in combination with inductively coupled plasma mass spectrometry (ICP-MS) and laser ablation (LA). Trace elements concentrates were evaporated on preliminarily prepared areas of a high-purity silicon substrate, after which an LA-ICP-MS analysis was performed. The influence of the LA parameters and the conditions for recording the spectra on the signal of the analytes and the substrate material was studied. The analytical capabilities of the thin layer method in combination with LA-ICP-MS for the analysis of high-purity substances with the preconcentration of trace elements were evaluated. Using an analysis of high-purity nitric acid as an example, it was shown that the limits of detection for analytes in the LA-ICP-MS analysis of trace element concentrates using the thin layer method are in the range from n × 10–11 to n × 10–8 wt %. Thus, the development of combined procedures of analysis, including the preconcentration of trace elements and an analysis of concentrates by LA-ICP-MS, makes it possible to reduce the limits of detection for most analytes by one order of magnitude compared to instrumental ICP-MS analysis. [ABSTRACT FROM AUTHOR]

A graphitic digestion method linked with inductive coupled plasma optical emission spectroscopy (ICP OES) instrument was used to determine the levels of trace elements in frozen and chilled chicken samples collected from markets in Jouf city, Saudi Arabia. The current method is innovative because samples are digested using a graphitic digestion system, which is safer, facile sample handling, short time for assessment, and more environmentally friendly than existing procedures. The results revealed that the chilled chicken samples contained higher concentrations of Na, Fe, Cr, and Mn than the frozen samples, which were below detection limit. Furthermore, the Cu, Al, Zn, and Cr contents in some of the analyzed chicken samples were over the maximum permissible limit of international standards, indicating a serious risk to consumers. The estimation of health-risk indicated that trace metal contamination causes health risks to the consumers, but the effect decreases with decreasing the target hazard quotient value in the rank of Cr > Al > Zn > Cu > Mn > Fe, with all values less than 1 except for Cr in chilled chicken. Moreover, the tolerable limit (1 × 10−6) for the carcinogenic risk for Cr in chilled chicken was observed to be exceeded. [ABSTRACT FROM AUTHOR]

At RF plasma reactors operated at high power, internal Faraday shields are required to shield dielectric vessel or windows from erosion due to isotropic heat and particle fluxes. By utilizing a flexible and diagnostically well-equipped laboratory setup, crucial effects that accompany the application of internal Faraday shields at low-pressure hydrogen (and deuterium) RF discharges are identified and quantified in this contribution. Both an inductively coupled plasma (ICP) utilizing a helical coil and a low-field helicon discharge applying a Nagoya-type III antenna at magnetic fields of up to 12 mT are investigated. Discharges are driven at 4 MHz and in the pressure range between 0.3 and 10 Pa while the impact of the Faraday shields on both the RF power transfer efficiency and spectroscopically determined bulk plasma parameters (electron density and temperature, atomic density) is investigated. Three main effects are identified and discussed: (i) due to the Faraday shield, the measured RF power transfer efficiency is globally reduced. This is mainly caused by increased power losses due to induced eddy currents within the electrostatic shield, as accompanying numerical simulations by a self-consistent fluid model demonstrate. (ii) The Faraday shield reduces the atomic hydrogen density in the plasma by one order of magnitude, as the recombination rate of atoms on the metallic (copper) surfaces of the shield is considerably higher compared to the dielectric quartz walls. (iii) The Faraday shield suppresses the transition of the low-field helicon setup to a wave heated regime at the present conditions. This is attributed to a change of boundary conditions for wave propagation, as the plasma is in direct contact with the conductive surfaces of the Faraday shield rather than being operated in a laterally fully dielectric vessel.

Measurements of ion flux-energy distribution functions at the high sheath potential of the driven electrode in a classical low-pressure asymmetric capacitively coupled plasma are technically difficult as the diagnostic device needs to float with the applied radio frequency voltage. Otherwise, the ion sampling is disturbed by the varying electric field between the grounded device and the driven electrode. To circumvent such distortions, a low-pressure plasma chamber with inverted electrode geometry, where the larger electrode is driven and the smaller electrode is grounded, has been constructed and characterized. Measurements of the ion flux-energy distribution functions with an energy-selective mass spectrometer at the high sheath potential of the grounded electrode are presented for a variety of conditions and ions. The potential for suppressing low-energy ions from resonant charge transfer collisions in the sheath by the dilution of the working gas is demonstrated. Additionally, the setup is supplemented by an inductively coupled plasma that controls the plasma density and consequently the ion flux to the substrate while the radio frequency bias controls the ion energy. At high ion energies, metal ions are detected as a consequence of the ionization of sputtered electrode material. The proposed setup opens a way to study precisely the effects of ion treatment for a variety of substrates such as catalysts, polymers, or thin films.

Aiming at the discharge problem of inductively coupled plasma (ICP), a closed wave-transmitting cavi-ty configuration is designed, the fluid mechanics model of ICP is established, and the multi physical simulation software COMSOL is used for three-dimensional simulation research. The variation laws of typical parameters such as electron density, electron temperature and plasma potential with time in the discharge process are analyzed. On this basis, the power of radio frequency power supply, the air pressure in the cavity and other conditions are changed to obtain the parameter range and spatial gradient distribution of ICP. The results show that the discharge power mainly affects the numerical range of plasma parameters, and the change of air pressure has an effect on the numerical value and spatial distribution of plasma parameters. When the power of radio frequency power supply increases from 100 W to 300 W, the peak electron density increases from 2.54×1017 m-3 to 5.68×1017 m-3, and the electric potential induced in the heating zone and the corresponding electron temperature decrease slightly after the reaction is stable. Increasing the air pressure in the cavity within a certain range will significantly increase the electron density. The air pressure increases from 10 Pa to 30 Pa, and the electron density increases from 9.12×1017 m-3 to 3.62×1018 m-3. However, the uniformity of plasma parameter distribution will deteriorate if the air pressure is too high.

Inductively coupled plasma or ICP sources form a basis for multiple applications ranging from semiconductor fabrication to reliable heating systems for tokamak machines. To meet the functional requirements, ICP sources need efficient plasma formation utilizing the various input parameters. Operation of ICP sources is a complex and challenging task since it involves scanning a wide multi-dimensional parameter space involving filament bias, radio frequency (RF) power, gas pressure, matching parameters, and other system configurations. The foremost challenge is to maximize the coupling of RF power in the ion source for efficient plasma formation. Standard ICP sources use a matching network that consists of variable capacitors to compensate for plasma inductance to enable maximum power coupling. Identification of an accurate set of matching parameters for high power sources is a complex task and is generally driven by operator experience which is established after years of operations. Due to these challenges, recent developments in the area of machine learning can be utilized for identifying the underlying model function to make accurate predictions and explore an alternative approach to the existing Physics-electrical models developed for the estimation of matching parameters for plasma sources. The present work attempts to perform a data-driven model discovery for the identification of appropriate matching parameters utilizing machine learning algorithms. In this work, ROBIN, a high-power ICP source that operates with a 1MHz, 100 kW RF generator is considered which has been operational since 2011 and has generated a considerable database. This database can be utilized for training/developing data-driven models for the estimation of matching parameters for ensuring better power coupling. The paper describes the development of two data-driven regression models for predicting the coupling efficiency in terms of power factor (denoted by Cos ϕ) and the capacitor values based on input parameters utilizing well known algorithms such as support vector machine, random forest and neural networks. Emphasis has been laid on developing the models using parameters that are tuneable externally. Also, the effect of system configurations on parameter prediction is investigated. The developed machine learning-based models have achieved test accuracy scores of 0.93 and 0.91 for predicting Cos ϕ and capacitor values respectively. The paper presents the training and optimization process for various machine and deep learning algorithms in detail. • Estimation of matching parameters for RF plasma in an ICP source using ML is explored. • Various ML algorithms are compared for predictive modelling of parameters. • Optimization techniques for tuning ML and Neural network-based model are presented. • Mode based performance is explored for trained models. [ABSTRACT FROM AUTHOR]

Plasma anisotropic etching polishing (plasma-AEP), a non-contact polishing method, is proposed to achieve highly efficient planarization of polycrystalline diamond (PCD) films. Inductively coupled plasma, with a high concentration of reactive radicals, serves as the source of plasma-AEP. In-situ observation confirms that the planarization effect of plasma-AEP is realized through the preferential removal of the top areas of the pyramid-shaped protrusions, despite the entire surface being uniformly irradiated by the plasma. The material removal rate in plasma-AEP for PCD achieves 127 μm/min. Plasma-AEP is proven effective for PCD films with thicknesses of 0.5, 1, and 2 mm, demonstrating a generic semi-finishing approach for PCD regardless of thickness. Atomic-scale nudged elastic band calculations revealed that the energy barriers for CO and CO 2 desorption from 1- and 2-coordinated C atoms are significantly lower than those for 3- and 4-coordinated ones. ReaxFF molecular dynamics simulations showed that at the top areas of the pyramid-shaped protrusions, 1- and 2-coordinated C atoms with a higher etching priority remained dominant during plasma-AEP, leading to the preferential removal of C atoms forming these protrusions. Furthermore, contact polishing was added to complete the finishing of the PCD film, followed by plasma-AEP, resulting in a nanoscale smooth surface with a roughness of 3.4 nm. Transmission electron microscopy confirmed that the crystal structures on the surface and subsurface of the PCD film were well ordered. Overall, this paper displays that plasma-AEP is a promising approach for highly efficient semi-finishing of PCD films. [Display omitted] • Plasma anisotropic etching polishing (plasma-AEP) is developed. • Preferential removal of protrusions on polycrystalline diamond (PCD) is confirmed. • The anisotropic etching characteristic is revealed by multi-scale simulations. • Plasma-PAE is generic for semi-finishing PCD with various thicknesses. • Contact polishing is added to achieve nanoscale finishing of PCD. [ABSTRACT FROM AUTHOR]

Global modeling of inductively coupled plasma (ICP) reactors is a powerful tool to investigate plasma parameters. In this article, the argon ICP global model is revisited to explore the effect of excited species on collisional energy through the study of different approaches to particle and energy balance equations. The collisional energy loss is much more sensitive to modifications in the balance equations than the electron temperature. According to the simulations, the multistep ionization reduces the collisional energy loss in all investigated reaction sets and the inclusion of heavy species reactions has negligible influence. The plasma parameters obtained, such as total energy loss and electron temperature, were compared with experimental results from the literature. The simulated cases that have more excited species and reactions in the energy balance are in better agreement with the experimental measurements.

With the growing demands for transferring large amounts of data between components in a package, it is required for advanced packaging technologies to form smaller vertical vias in the insulators. Plasma etching is one of the most widely used micro-vias formation processes. This paper has developed a fabrication process for 5–10 µm residue-free micro-vias with 70° tapered angle in polyimide film based on O2/CHF3 inductively coupled plasma (ICP). The etch rate would monotonically increase with the ICP power, RF power, and gas flow rate. As for the gas ratio, there is an optimum range of CHF3 ratio, which could obtain the highest etch rate. The results have clearly shown that the enhancement of ion bombardment and prolongation of etching time would be beneficial to grass-like residue removal. In addition, during the etching of partially cured polyimide, the lateral etch rate would significantly increase in the region near the metal hard mask. [ABSTRACT FROM AUTHOR]

This paper presents a physics-based 0-D steady-state model of a radiofrequency ion thruster (RIT) that is valid for any propellant blend, and hence, any plasma mixture, and the model is used to predict the drag compensation capability and plasma composition of an air-breathing RIT operating in very-low Earth orbit (VLEO). This study fills a gap in the modeling of air-breathing electric propulsion with an air-breathing RIT model that is validated with experimental data of a RIT operating with an N 2 / O 2 mixture. The model expands upon current 0-D RIT models by accounting for the dissociation of neutral molecules and molecular ions and by applying particle conservation for each ion and neutral species. Atomic oxygen in the atmosphere is assumed to completely recombine into O 2 in the collector, and the model is used to calculate an air-breathing RIT's thrust, discharge efficiency, mass utilization efficiency, and discharge plasma composition at altitudes between 80 and 150 km. At 1 kW of total input power and an optimal flow rate of 0.17 mg/s, the net thrust was limited to 3 mN at all altitudes considered. At these same operating conditions, the mass utilization efficiency and discharge efficiency were approximately 0.15 and 870 eV/ion, respectively. To increase the performance of the thruster, the magnetic field should be increased in order to increase the beam current. The mole fraction of atomic oxygen in the discharge chamber was found to be between 0.19 and 0.27 depending on the altitude, indicating that grid erosion should be a focus of future studies. [ABSTRACT FROM AUTHOR]

For use in additive manufacturing (AM), powders that have a spherical shape, high fluidity, and packing density are required. One of the methods for producing spherical powders is spheroidization using inductively coupled plasma. In this work, the powder of steel grade EI961 was used. To obtain the powder for subsequent use in 3D printing, the selection of modes was carried out with the change in various parameters of the unit: different power, powder feed rate to the plasma as well as the height of feed rate. The optimal spheroidization mode is as follows: power of 15 kW, pressure of 1 atm, feed rate height of 0 mm, and powder feed rate of 28 g·min−1. The temperature distribution over the plasma torch cross section was calculated and the maximum plasma temperature was also determined. In addition, the effect of plasma treatment on the granulometric composition, phase composition, and chemical composition was studied.

Abstract In this study, seven pretreatment methods for chromium speciation in tanned leather were evaluated: acidic mineralization, ethylenediaminetetraacetic acid (EDTA) extraction, diethylenetriaminepentaacetic acid (DTPA) extraction, alkaline extraction (NH4OH), ammonium nitrate extraction (NH4NO3), water extraction, and phosphate buffer extraction. Acidic mineralization permitted the decomposition of the organic matter and ensured the complete digestion of leathers, giving access to the total content of chromium in each sample using inductively coupled plasma-atomic emission spectrometry (ICP-AES). From all the extractant media tested, EDTA proved to be the most efficient, allowing the extraction of Cr(VI) and Cr(III) as a Cr(III)-EDTA complex, quantitatively. Method validation is presented for EDTA extraction and direct mineralization. For the EDTA extraction, method detection limit (MDL) and method quantification limit (MQL) for total Cr in leather were 3.4 ppb and 11.2 ppb (µg of total Cr per L of extraction solution), respectively. Due to the lack of leather certified reference materials (CRMs) for Cr(VI), accuracy was evaluated by spiking leather samples with a Cr(VI) solution. The spike recovery of EDTA microwave assisted extraction ranged from 91.0 to 108.6%. Interday precision was also evaluated and all variation coefficients were below 5%, for both mineralization and EDTA extraction. This article provides an efficient procedure to extract quantitatively chromium from leather, while maintaining the speciation, which can be further followed by ion chromatography-inductively coupled plasma-mass spectrometry (IC-ICP-MS).

A novel home-made H2SO4-Nafion (HN) tube sampling system coupled to a line ion trap mass spectrometer (LTQ-MS) with a versatile ambient ionization source, hectowatt microwave plasma torch (HMPT), has manifested unique advantages for picking directly metal elements in aqueous samples and acquiring the fully characteristic MPT mass spectra of copper and zinc composite ions. Here, we report the development of a novel HN-HMPT-LTQ-MS for metal elements assay based on environmental water to analyze samples of Poyang Lake, China. Detailed multi-stage tandem mass spectra show that the general structural form of target ions is [M(NO3)x(H2O)y(OH)z]+ for the positive ion mode. Under the optimized conditions, the proposed method provided low limits of detection (LODs) of 0.23 μg.L−1 for 63Cu+ and 1.1 μg.L−1 for 66Zn+, with relative standard deviations (RSDs) of less than 12.7% by MPT-LTQ-MS. This new result has met the requirements of national standards (GB 5750.6–2006) and is only about one magnitude order larger than the LOD of ICP-MS method. A wide linear response range of about 4 orders of magnitude for the method with linear coefficients (R2) of 0.99709 – 0.99962 for copper and zinc tested was in accordance with that of ICP-MS. Except for the recovery of 79% for the third sample and 123.8% for the seventh sample, the present method also provided good recoveries (84 – 119.3%) in spiked 10 batches of drinking water samples. Furthermore, it is envisioned that the developed approach might build a powerful hectowatt-MPT-MS platform for food security detection, drug analysis, and origin traceability. [ABSTRACT FROM AUTHOR]

A plasma system attached with one internal coil (for generating inductively coupled plasma) and two sputtering carbon targets was set up to deposit PP-MMA (plasma polymerized methyl methacrylate) thin films. PP-MMA was used as a model material in the present study. In the experiment, the working pressure and Ar/MMA flow ratio were varied, which resulted in the change in plasma conditions as well as the deposition rates. The optical emission spectroscopy (OES) method was applied to identify the presence of the excited species related to the fragmented monomer. In addition, the electron temperature and electron density were determined using the modified Boltzmann plot and line-ratio method, according to the measured OES spectra. The deposition rate of the PMMA film was then correlated with the determined plasma characteristics. To determine the vibrational modes of the deposited PP-MMA films, Fourier transformed infrared spectrometry (FTIR) was used. The highest deposition rate of PP-MMA could be obtained with the optimized working pressure and Ar/MMA volume ratio. This could be related to the plasma characteristics that contribute to the fragmentation of the monomer in the plasma. [ABSTRACT FROM AUTHOR]

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BackgroundThe ion source is one of the key components of the neutral beam injection system. Radio frequency (RF) ion source has the advantages of long life time, easy maintenance and long pules operation, which make it the main alternative source for the neutral beam ion source in the future.PurposeThis study aims to analyze equivalent impedance characteristics of a high power RF ion source driver with emphasis on the impedance matching network and effective tuning of matching network to achieve high-power and stable plasma discharge.MethodsFirst of all, the analytical model was established on the basis of transformer model. The plasma conductivity was obtained by estimating the ohmic heating frequency and stochastic heating frequency in the plasma. Then, the equivalent impedance of the plasma was coupled to the excitation coils with the transformer model, and the equivalent impedance of the driver was obtained. Finally, parameters of the single drive RF ion source of negative ion based neutral beam injection (NNBI) system of Comprehensive Research Facility For Fusion Technology (CRAFT) were taken as example to calculate variation of equivalent impedance of actuator with plasma electron density by MATLAB code.Results & ConclusionsComputation results show that the analytical model proposed in this study can be used to quickly and accurately calculate the electron temperature in the driver under different gas pressures, and the equivalent impedance under different gas pressures and electron densities, which provides a reference for the reasonable design and tuning of impedance matching network.

A method for determining the mass concentration of phosphorus in a water-oil emulsion used for wire drawing by inductively coupled plasma optical emission spectrometry has been developed. Phosphorus enters the emulsion after etching the wire in a solution of orthophosphoric acid, which removes oxides that have appeared in the process of forming brass. It is one of the determined indicators that additionally characterizes the state of the emulsion during operation.This creates an insoluble phosphate film. The resulting phosphate film layer should not be too thick, as it has a negative effect on further processing (an additional factor of contamination of the emulsion on thin drawing).The most promising method for determining harmful impurities in an emulsion, including phosphorus, is optical emission spectrometry with inductively coupled plasma. The method is based on the sputtering of the analyzed sample in an argon plasma excited by a high-frequency electromagnetic field. To determine the mass concentration of phosphorus, it is necessary to perform calibration of the inductively coupled plasma spectrometer. To check the correctness of the calibration, a control sample is used, which is prepared from the state standard sample (SSS) of the composition of an aqueous solution of phosphate ions. Next, it is necessary to prepare working samples of solutions of water-oil emulsion. Then, the mass concentration of phosphorus in the analyzed sample is measured using an inductively coupled plasma optical emission spectrometer Ultima Expert (HORIBA, France).Accuracy indicators, extended uncertainty of measurement results for the method are calculated in accordance with STB ISO 5725-2.

Conventional methods to measure the metallic content of particles by size are time consuming and expensive, requiring collection of particles with a cascade impactor and subsequent metals analysis by inductively coupled plasma mass spectrometry (ICP-MS). In this work, we describe a rapid way to measure the size distribution of metal-containing particles from 10 nm to 20 μm, using a nano micro-orifice uniform-deposit impactor (nano-MOUDI) to size-selective and collect particles that are then analyzed with a field portable X-ray fluorescence (FP-XRF) to determine metal composition and concentration. The nano-MOUDI was used to sample a stainless-steel aerosol produced by a spark discharge system. The particle-laden substrates were then analyzed directly with FP-XRF and then with ICP-MS. Results from FP-XRF were linearly correlated with results from ICP-MS (R2 = 0.91 for Fe and R2 = 0.84 for Cr). Although the FP-XRF was unable to detect Fe particles at mass per substrate loadings less than 2.5 μg effectively, it produced results similar to those using the ICP-MS at a mass per substrate loading greater than 2.5 μg.

In this work, we studied the effect of power variation ​​on inductively coupled plasma parameters using numerical simulation. Different values ​​were used for input power (750 W-1500 W), gas temperature 300K, gas pressure (0.02torr), 5 tourns of the copper coil and the plasma was produced at radio frequency (RF) 13.56 MHZ on the coil above the quartz chamber. For the previous purpose, a computer simulation in two dimensions axisymmetric, based on finite element method, was implemented for argon plasma. Based on the results we were able to obtain plasma with a higher density, which was represented by obtaining the plasma parameters (electron density, electric potential, total power, number density of argon ions, electron temperature, number density of excited argon atoms) where the high density in the generated plasma provides a greater degree in material processing, which increases the efficiency of the system. These results may aid in future research towards the development of more efficient optimization of plasma parameters which are (electron density, electric potential, total power, number density of argon ions, electron temperature, and number density of excited argon atoms).

This article reports results of the design and experimental investigation of a high-flow and high-concentration NOx production system based on a radio-frequency plasma torch for a variety of applications. The system includes a commercial APT-100 plasma torch with plume power from 25 to 35 kW, a double-stage quenching reactor with “fast” first stage and “slow” second stage, measuring unit, and auxiliary systems. The first stage allows quenching by any gas, such as air, air-based blends, and the products of recirculation. [ABSTRACT FROM AUTHOR]

To study the characteristics of radio frequency (RF) power coupling, RF plasma diagnostics, actively cooled tube, and negative ion production, a plasma source was designed as a small-scale test facility. The matching network was carefully designed and successfully applied to the 2-MHz RF plasma source. In this article, the design method of the matching unit will be presented; with the assistance of this matching unit, the RF plasma source was successfully lit and the reflected power was reduced to a very low level. A $V\!\!-\!\!I$ probe was installed in front of or in the rear of the matching network, respectively, to in situ measure the RF voltage, current, and phase angle. The equivalent resistance of the RF plasma source was analyzed in detail. The RF power coupling efficiency was derived in two different methods, and the relationship between the coupling efficiency and the equivalent resistance of the plasma source is verified. At the same time, the equivalent resistance of the plasma source was also collected to optimize the matching unit. [ABSTRACT FROM AUTHOR]

Nanopatterning of GaN/AlN layers on Silicon-On-Insulator (SOI) substrates is discussed with the aim of fabricating nanopillar arrays that can be used for subsequent GaN pendeo-epitaxy. The principle of the developed epitaxy process is that GaN crystallites are grown on deformable nano-pedestals able to rotate at GaN growth temperature. The objective is to control the complete pattern profile of GaN/AlN/Si/SiO2 pillars, both in lateral and vertical directions. Since a smaller pillar diameter should enhance the pillar rotation at growth temperature, special emphasis will be given to nanometer-scale pillars. In this context, the control of GaN/AlN vertical sidewalls is still an issue for high-resolution nanopillars. In this paper, we report on the optimization of the plasma etching processes of GaN/AlN/Si/SiO2 stacks to reduce the slope that widens the pillar base. Overall, we achieve near perfect arrays of 100 nm diameter nanopillars obtained by combining NanoImprint Lithography (NIL) and plasma etching, with bases of 150 nm in diameter.

Background: Ion and metal homeostasis are critical to red blood cell physiology and Inductively Coupled Plasma (ICP) is a decades old approach to pursue elemental analysis. Recent evolution of ICP has resulted in its coupling to mass spectrometry (MS) instead of atomic absorption/emission. Methods: Here we performed Inductively-coupled plasma mass spectrometry (ICP-MS) measurements of intra- and extra-cellular Na, K, Ca, Mg, Fe, and Cu in red blood cells undergoing ionic, heat, or starvation stress. Results were correlated with Ca measurements from other common platforms (e.g., fluorescence-based approaches) and extensive measurements of red blood cell metabolism. Results: All stresses induced significant intra- and extracellular alterations of all measured elements. In particular, ionomycin treatment or hypertonic stress significantly impacted intracellular sodium and extracellular potassium and magnesium levels. Iron efflux was observed as a function of temperatures, with ionic and heat stress at 40°C causing the maximum decrease in intracellular iron pools and increases in the supernatants. Strong positive correlation was observed between calcium measurements via ICP-MS and fluorescence-based approaches. Correlation analyses with metabolomics data showed a strong positive association between extracellular calcium and intracellular sodium or magnesium levels and intracellular glycolysis. Extracellular potassium or iron were positively correlated with free fatty acids (especially mono-, poly-, and highly-unsaturated or odd-chain fatty acid products of lipid peroxidation). Intracellular iron was instead positively correlated with saturated fatty acids (palmitate, stearate) and negatively with methionine metabolism (methionine, S-adenosylmethionine), phosphatidylserine exposure and glycolysis. Conclusion: In the era of omics approaches, ICP-MS affords a comprehensive characterization of intracellular elements that provide direct insights on red blood cell physiology and represent meaningful covariates for data generated via other omics platforms such as metabolomics. [ABSTRACT FROM AUTHOR]

The pre-treatment condition affects on the element analysis of inductively coupled plasma (ICP). In this study the pre-treatment condition of ICP has been studied to quantify elements in dog’s hair. The hair samples were collected from twelve female Beagles by clipping them into 1 or 2 cm at the back neck. The qualitative and quantitative analysis of elements in hairs were performed by using ICP. By ICP nine elements were qualitatively detected and quantitatively analyzed (Ca, Cu, Fe, K, Mg, Na, P, Se, Zn). The measured amounts of elements were compared between 3 step and 2 step procedures which were with and without the acetone based washing step. The quantitative analysis showed that the concentrations of K, Na, P, and Se were significantly decreased in hair samples with acetone-based washing (p < 0.005 or 0.001) unlike those without the acetone-based washing. It implied that some minerals are lost by the acetone based washing during the sample preparation step. Therefore, the acetone based washing process is not suitable for quantifying elements in dog’s hair. In addition, the results of qualitative and quantitative analysis were compared. Although there was a difference in absolute values of elemental contents in hair, the results of qualitative and quantitative analysis were significantly correlated each other. This finding suggested that the results of qualitative analysis can be used to monitor elemental contents in dog’s hair.

BackgroundIon and metal homeostasis are critical to red blood cell physiology and Inductively Coupled Plasma (ICP) is a decades old approach to pursue elemental analysis. Recent evolution of ICP has resulted in its coupling to mass spectrometry (MS) instead of atomic absorption/emission.MethodsHere we performed Inductively-coupled plasma mass spectrometry (ICP-MS) measurements of intra- and extra-cellular Na, K, Ca, Mg, Fe, and Cu in red blood cells undergoing ionic, heat, or starvation stress. Results were correlated with Ca measurements from other common platforms (e.g., fluorescence-based approaches) and extensive measurements of red blood cell metabolism.ResultsAll stresses induced significant intra- and extracellular alterations of all measured elements. In particular, ionomycin treatment or hypertonic stress significantly impacted intracellular sodium and extracellular potassium and magnesium levels. Iron efflux was observed as a function of temperatures, with ionic and heat stress at 40°C causing the maximum decrease in intracellular iron pools and increases in the supernatants. Strong positive correlation was observed between calcium measurements via ICP-MS and fluorescence-based approaches. Correlation analyses with metabolomics data showed a strong positive association between extracellular calcium and intracellular sodium or magnesium levels and intracellular glycolysis. Extracellular potassium or iron were positively correlated with free fatty acids (especially mono-, poly-, and highly-unsaturated or odd-chain fatty acid products of lipid peroxidation). Intracellular iron was instead positively correlated with saturated fatty acids (palmitate, stearate) and negatively with methionine metabolism (methionine, S-adenosylmethionine), phosphatidylserine exposure and glycolysis.ConclusionIn the era of omics approaches, ICP-MS affords a comprehensive characterization of intracellular elements that provide direct insights on red blood cell physiology and represent meaningful covariates for data generated via other omics platforms such as metabolomics.

In this study, seven pretreatment methods for chromium speciation in tanned leather were evaluated: acidic mineralization, ethylenediaminetetraacetic acid (EDTA) extraction, diethylenetriaminepentaacetic acid (DTPA) extraction, alkaline extraction (NH4OH), ammonium nitrate extraction (NH4NO3), water extraction, and phosphate buffer extraction. Acidic mineralization permitted the decomposition of the organic matter and ensured the complete digestion of leathers, giving access to the total content of chromium in each sample using inductively coupled plasma-atomic emission spectrometry (ICP-AES). From all the extractant media tested, EDTA proved to be the most efficient, allowing the extraction of Cr(VI) and Cr(III) as a Cr(III)-EDTA complex, quantitatively. Method validation is presented for EDTA extraction and direct mineralization. For the EDTA extraction, method detection limit (MDL) and method quantification limit (MQL) for total Cr in leather were 3.4 ppb and 11.2 ppb (µg of total Cr per L of extraction solution), respectively. Due to the lack of leather certified reference materials (CRMs) for Cr(VI), accuracy was evaluated by spiking leather samples with a Cr(VI) solution. The spike recovery of EDTA microwave assisted extraction ranged from 91.0 to 108.6%. Interday precision was also evaluated and all variation coefficients were below 5%, for both mineralization and EDTA extraction. This article provides an efficient procedure to extract quantitatively chromium from leather, while maintaining the speciation, which can be further followed by ion chromatography-inductively coupled plasma-mass spectrometry (IC-ICP-MS). [ABSTRACT FROM AUTHOR]

An atmosphere-breathing electric propulsion system (ABEP) uses the rarefied atmospheric molecules as the propellant for the electric thruster. In the best case, it can allow spacecraft (S/C) complete a long-time mission in very low Earth orbit (VLEO) without carrying any propellant. However, previous studies have shown that the thruster lifetime is limited by electrode erosion due to the aggressive gases, such as the atomic oxygen in VLEO. This paper design and analyse an inductively coupled plasma generator (ICPG) for ABEP system, and it is electrodeless to avoid electrode erosion. Based on the COMSOL Multiphysics, the simulation model of ICPG is established and analyzed. Multiple physical fields are coupled in this model including plasma, magnetic field, and flow field. The simulation model is verified by the experimental results of the literature. Driving by the radio frequency power, the plasma power distribution and thrust estimation of the ICPG under different input conditions (different drive powers and different operation gases) can be obtained. The results show that the ICPG may have a better performance under the condition of low mass flow and high drive power to compensate the drag. The gas species and their proportions have also great influence on the behaviours of ICPG. This paper can provide a convenient and efficient method to study the ICPG products for ABEP. • Inductive plasma source: contactless device, avoids electrode erosion. • Collects and uses planet's atmosphere as propellant. • Compensates drag of satellites at very low altitudes. • A Simulation model verified to analyse the performance of plasma and thrust, accurately and quickly. • The results of plasma power and thrust help to improve the performance of ICPG for ABEP system. [ABSTRACT FROM AUTHOR]

With the growing demands for transferring large amounts of data between components in a package, it is required for advanced packaging technologies to form smaller vertical vias in the insulators. Plasma etching is one of the most widely used micro-vias formation processes. This paper has developed a fabrication process for 5–10 µm residue-free micro-vias with 70° tapered angle in polyimide film based on O2/CHF3 inductively coupled plasma (ICP). The etch rate would monotonically increase with the ICP power, RF power, and gas flow rate. As for the gas ratio, there is an optimum range of CHF3 ratio, which could obtain the highest etch rate. The results have clearly shown that the enhancement of ion bombardment and prolongation of etching time would be beneficial to grass-like residue removal. In addition, during the etching of partially cured polyimide, the lateral etch rate would significantly increase in the region near the metal hard mask.

Background: We investigated the human risk due to radon and heavy metals (HM) in soil. Methods: Samples were collected in 2017 from 10 representative geographical locations at Jazan region of southwestern Saudi Arabia and analyzed for elements (Al, Ca, Cu, Ni, Sr Fe, Mg, B, Co, Cr, V, Zn, Mn, Ba, Cd, and Pb). Elements were measured using inductively coupled plasma optical emission spectrometer (ICP-OES). Radon (Rn) was measured using solid-state nuclear detector (SSNTDs). Results: The maximum human risk was due to Al, which had the highest concentration, where the lowest human risk was due to Cd. The maximum radon concentration was obtained at El-Mazab area with value of 381.05 Bq/m3which leads to 6.55 mSv/y and 78.94 Bq/m2d annual effective doses and radon exhalant rate respectively. Average equivalent and effective dose to different organs due to radon concentration was estimated. Hazard Index due to both carcinogenic and non-cancer hazards were calculated it exceeds permissible level for child due to Nickel and Chromium hence there is a significant risk on children in the study area. Conclusion: HM concentrations were over limits in some places according to the human activities, municipal waste disposal, fertilizers and pesticides in agriculture. In addition, soil is porous permit dispersion of radon to the atmosphere.

This paper describes an inductive discharge with ferromagnetic enhancement of magnetic coupling between an inductor and a discharge, generated at atmospheric pressure of plasma forming gas. It is shown that amplifying a magnetic flux that connects the inductor and the plasma makes it possible to efficiently generate an electrodeless discharge in a low-frequency (10–100 kHz) range and greatly simplifies the use of the inductively coupled plasma. This study also presents new experimental data on the dependence of the electric field strength and the thermal efficiency of a low-frequency induction discharge of atmospheric pressure on the discharge current strength and the flow rate of a plasma-forming gas (argon or air). It is shown how a low-frequency inductive discharge maintenance criterion is related to its thermal efficiency, and methods for reducing the heat losses of a low-frequency inductive discharge of atmospheric pressure are analyzed. [ABSTRACT FROM AUTHOR]