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The objective of this article is to enhance the dc insulation strength of poly- ${m}$ -phenylene isophthalamide (PMIA) paper by surface treatment. CF4/Ar plasma is used to modify the surface of PMIA paper by fluorination, and the effects of fluorination on the microstructure, electrical parameters, and insulation properties of the material are investigated, and the optimized treatment parameters of CF4 concentration and treatment time are obtained, and the mechanism is further explained from the perspective of carrier traps. The results show that the moderate CF4/Ar plasma treatment can improve the surface insulation properties of PMIA paper without damaging its overall insulation properties. [ABSTRACT FROM AUTHOR]

This paper reports on the behavior of red and black ink from a historical printed book, subjected to a plasma discharge treatment, applied for the decontamination and cleaning of naturally aged paper. As some preliminary experiments using high-frequency (HF) plasma showed a slight fading of red ink, the study was focused on the comparison of HF cold plasma and afterglow plasma treatments in order to get conclusive information on the effect of plasma active species on the red ink. Energy Dispersive X-ray Scanning Electron Microscopy SEM-EDX and Attenuated Total Reflection Fourier-Transform Infrared Spectroscopy FTIR-ATR analyses were used for the identification of inks and binder, while the impact of plasma on inks was assessed by SEM analysis and color determinations. The experiments have been performed on an especially designed modular equipment, allowing the samples to be subjected alternately to HF cold plasma or afterglow plasma treatment. The study proved that direct HF plasma could result in a more important deterioration at treatment duration exceeding 5 min, while in afterglow plasma, this discoloration is not observable. The color fading is imputable to the corrosion of pigment crystallites produced by direct plasma discharge. [ABSTRACT FROM AUTHOR]

A low-cost and simple-arranged paper-based microplasma array device made by tape and Xerox paper was presented. Uniform array of discharge can be sustained in Ar, He, and ambient air atmosphere. Stable discharge can be sustained for at least 55 min when plasma is ignited in Ar ambient, based on the examination of time-resolved optical emission spectra. Throughout the conditions investigated, the power consumed by the device was well below 0.3 W. We also demonstrated that stable and uniform discharge can be generated when the device was bent to a radius of curvature of 2.5 mm. [ABSTRACT FROM PUBLISHER]

We report the fabrication of a plasma-generating device on a paper substrate. This device was fabricated using a screen print process. Plasmas were ignited between two parallel electrodes with a plasma gap of 237 to 710 \mu\m using a dc power source. We demonstrated that a stable helium plasma can be sustained when the substrate is flat, rolled, and folded along various orientations. When the plasma was ignited with a 0.2-\mu\L salt solution droplet with 1.4, 4.6, and 7.8 ng of Li, Na, and K respectively applied to the discharge gap, clear metallic emission lines emanated from the plasma. Our result demonstrates that this paper-based plasma device can be used in analytical applications.\hfill[2012-0006] [ABSTRACT FROM AUTHOR]

This letter presents a simple and economical paper-based device that is able to generate an array of stable Ar microdischarges. This is a dielectric-barrier-discharge device that exhibits filamentary-type features. The device is sustained by an ac voltage with a 550-V amplitude and 10-kHz frequency. Optical emission spectra show that Ar lines dominate the emission, with a trace amount of CH and \C2 emissions. Despite slight damage, the electrode lifetime exceeds 20 min. Results demonstrate that this device is flexible and is able to achieve maskless patterning of hydrophilic patterns on flat and curved glass surfaces.\hfill[2012-0361] [ABSTRACT FROM PUBLISHER]

This paper proposes a novel method for Virtual Metrology (VM) in plasma etch processes based on analysis of all time and wavelength samples of Optical Emission Spectroscopy (OES) signals. The new method flattens each OES signal into a single vector, after which Singular Value Decomposition (SVD) is performed on the matrix formed by vectors of flattened OES signals in the training dataset. Low rank SVD projections of flattened and standardized OES recordings served as inputs for Ridge Regression, Artificial Neural Network, and Random Forest based VM models. A VM study is then conducted on a dataset gathered from a major 300 mm wafer fabrication facility, showing that the use of newly proposed SVD-based OES features consistently outperformed benchmark VM model features. Additional analysis of feature importance performed based on the analytically tractable Ridge Regression VM model form demonstrated distinct time-frequency patterns of OES signal portions that were highly informative for prediction of relevant Critical Dimensions, clearly justifying the need to use the entire OES signals for VM. [ABSTRACT FROM AUTHOR]

The 16th version of the Latin American Workshop on Plasma Physics (LAWPP 2017) took place at the main campus of the Universidad Nacional Autónoma de México, Mexico City, Mexico, on September 4, 2017—September 8, 2017, organized by the Sociedad Mexicana de Física Division of Plasma Physics. This was the third time LAWPP was held in Mexico, following those in 1992 and 2005. The main mission of this series of meetings is to promote plasma physics in the region, providing a proper forum, as well as collaborations between scientists within Latin America, and broadly across the world. However, while it is a regional event in nature, it fulfilled its objective of bringing in an important international undertone. Furthermore, a wide range of topics were covered, in the fields of space and astrophysical plasmas, controlled nuclear fusion, laser-produced plasmas, dense magnetized plasmas, and industrial and environmental applications of plasmas. [ABSTRACT FROM AUTHOR]

The IEEE International Conference on Plasma Science (ICOPS) is an annual meeting of the plasma physics community known for the broad range of topics addressed as well as for its varied international locations. The 42nd ICOPS was held in Belek, Antalya, Turkey, on May 24–28, 2015. It was the first time that ICOPS was held in Turkey and the region. The General Chair of ICOPS 2015 was Prof. Lütfi Öksüz from Suleyman Demirel University (Isparta, Turkey), the Technical Program Chair was Dr. Christine Coverdale from Sandia National Laboratories (Albuquerque, NM, USA), and the conference Liaison was Prof. Edl Schamiloglu from the University of New Mexico (Albuquerque, NM, USA). As is traditional, the conference consists of all plasma science topics including 7 technical sessions and 35 subsessions. There were almost 400 registrants at ICOPS 2015, and over 500 abstracts are included in the conference. This ICOPS 2015 meeting especially attracted attendance from the Middle East, China, and Russia. [ABSTRACT FROM PUBLISHER]

Titanium tetrachloride (TiCl4) is a well-known source of titanium (Ti) for the formation of titanium nitride (TiN) barrier material in the semiconductor interconnection process; however, the reaction of by-products with airborne molecules can cause unexpected pump trips and equipment breakdown from the by-product powder build-up. Plasma scrubbers are used to decompose by-products, but hydrogen chloride (HCl) and nitrogen oxides are produced during and after the process. The process mechanisms change when the temperature and applied power of the heat source change. In this paper, we study the influence of the reactor temperature and applied power to the heat source on the decomposition capacity of TiCl4 in a plasma pretreatment system (PPS). We examine the effect of the temperature and heat source power to understand the reaction mechanisms for the composition and decomposition of gaseous species with chemical reactions through simultaneous methods. We analyzed the system with computational fluid dynamics (CFD) and chemical kinetic simulation to investigate the changes of the system mechanism. Subsequently, we achieved results for the correlation between the temperature of the reactor, power applied to the heat source, composition and decomposition of species, and chemical reaction mechanisms. [ABSTRACT FROM AUTHOR]

Semiconductor manufacturing processing can be jeopardized due to process fluctuations, and the degradation of equipment parts can significantly influence process variation. Timely diagnosing equipment faults causing process variations is desired in current high-end product manufacturing. This paper proposes a diagnostic method for the SiH4 gas flow rate drift using N2 vibrational transition in oxide deposition. In this research, optical emission spectroscopy (OES) and quadrupole mass spectrometer (QMS) are employed as condition monitoring sensors serving as a reference model to compare the diagnostic performance for gas flow rate drift. The study observes that the OES model exhibits much higher performance for minor diagnoses of less than 5% drift. The diagnostic model performance can be enhanced by incorporating plasma condition and gas indicators compared to when these indicators are used individually. This suggests that when conducting diagnostics for equipment and processes, it is crucial to consider indirect indicators like plasma indicators along with direct indicators such as gas radical density. The comprehensive use of both types of indicators enhances the diagnostic performance, providing a more accurate assessment of the conditions and potential problem in semiconductor manufacturing. [ABSTRACT FROM AUTHOR]

Welcome to the 27th Symposium On Fusion Engineering (SOFE) Special Edition of the IEEE Transactions on Plasma Science (TPS). [ABSTRACT FROM AUTHOR]

Interfacial bonding is significant in determining the mechanical properties and dielectric loss of polymer composites. In this study, NH3 plasma treatment is used to reinforce the interfacial bonding between polyisophthaloyl metaphenylene diamine (PMTA) and the cellulose matrix. The mechanism of modification is investigated via x-ray photoelectron spectroscopy (XPS) and density functional theory (DFT). Additionally, molecular dynamics (MD) simulations are performed to explore the microscopic mechanism of the performance improvement of the composite insulation paper. The experimental results show that the mechanical property is improved and dielectric loss decreased to a certain extent after treatment. According to the results of XPS and DFT, the treatment introduces a polar group, −NH2, into the C18 position of PMTA. PMTA treated with NH3 plasma (T-PMTA) is conducive to form H-bonds with cellulose. It increases the interaction energy and strengthens the interfacial bonding, causing the T-PMTA molecules to penetrate wider and deeper on the cellulose surface. Thus, the mechanical properties are improved. Additionally, the improved interfacial bonding impedes the rotation and movement of molecules at the interface, which reduces the degree of freedom of the dipole steering and the resulting low dielectric loss. This study reveals the mechanism of NH3 plasma treatment and provides insights into the microscopic mechanism of the improvement of properties of composite insulation paper at the molecular level. [ABSTRACT FROM AUTHOR]

The paper aims at assessing morphological and chemical changes on the surface of the cellulose-based materials, such as paper, induced by high frequency (HF) plasma discharge. The topic is discussed using capacitive coupled plasma discharge at 1.2 MHz, performed in Ar/O2 mixtures, on objects made up of natural polymers, such as lignocellulosic fibers. The preliminary findings indicate the possibility of using HF cold plasma discharge for obtaining the modified properties of the cellulose-based surfaces. Simultaneously, this treatment is well suited for cleaning and decontamination purposes. The improved wettability of the cellulose-based materials after surface activation in low pressure HF Ar/O2 plasma is favorable for a subsequent deposition of protective coating formulas specific in the conservation practices. [ABSTRACT FROM PUBLISHER]

The 2013 IEEE Pulsed Power and Plasma Science Conference (PPPS 2013) was held at the Hyatt Regency in San Francisco, CA, USA in June 2013. The PPPS 2013 combined the 19th IEEE Pulsed Power Conference (PPC) and the 40th IEEE International Conference on Plasma Science (ICOPS). This conference marks the third combined IEEE PPPS meeting, following the very successful PPPS 2001 in Las Vegas, NV, USA, and the PPPS 2007 in Albuquerque, NM, USA. The most recent ICOPS was held in 2012 in Edinburg, Scotland, and the most recent PPC was held in 2011 in Chicago, IL, USA. [ABSTRACT FROM PUBLISHER]

This paper presents the results of mathematical simulation of processes in argon-hydrogen inductively coupled plasma/radio frequency induction plasma torch for plasma chemical reactions. This first part starts a series of papers for simulation and study of plasma properties for a variety of gases and mixtures, which could be used for a number of prospective technologies. The results of mathematical simulation allow further research on the mechanisms of chemical reactions in argon-hydrogen plasma to increase effectiveness of obtaining the target product. [ABSTRACT FROM AUTHOR]

This paper proposes unconventional control techniques for a portable power supply consisting of electric double-layer capacitors (EDLCs), a dc–dc converter, and a low-impedance load such a plasma load. Between the EDLCs and the plasma load consuming high power, a dc–dc converter is required to control the output voltage from the rapidly decreasing voltage of EDLCs. In addition, the dc–dc converter should maintain a set point by responding to arcs occurred in plasma process. This paper proposed hybrid analog and digital controls for a nonideal boost converter which was setup by theoretical analysis. The proposed system is verified with experiment and simulation. As a result, the proposed control method can maintain the constant output voltage longer than a traditional analog pulsewidth modulation control. [ABSTRACT FROM AUTHOR]

This paper presents the development and description of research aimed at investigation of nanosecond surface microdischarge plasma effect on biomaterials. The technique is based on application of a simple discharge device. The device is assembled on a standard microscope slide from inexpensive materials. An optical microscope equipped with a digital camera is used for visualization of the studied samples and microdischarges. Many images of the microdischarges on the biological objects are presented in this paper. Spatial resolution of the images allows studying the discharges along the cellular structure of the tissue. [ABSTRACT FROM PUBLISHER]

The 41st IEEE International Conference on Plasma Science (ICOPS14) and the 20th IEEE International Conference on High-Power Particle Beams (Beams14) combined for the first time in 2014 as the IEEE ICOPS/Beams meeting. This scientific meeting took place from May 25 to May 29, 2014, in Washington, DC, at the historical Marriott Wardman Park hotel in Northwest DC. Participation included a broad range of scientific attendance, with a total of 566 researchers from 36 countries, with scientists from China, Russia, and Japan making the largest contribution to the international contingent. [ABSTRACT FROM PUBLISHER]

In current semiconductor manufacturing, limited raw trace data pertaining to defective wafers make fault detection (FD) assignments extremely difficult due to the data imbalance in wafer classification. To mitigate, this paper proposes using a variational autoencoder (VAE) as a data augmentation strategy for resolving data imbalance of temporal raw trace data. A VAE with few defective samples is first trained. By means of extracting the latent variables that characterize the distribution of the defective samples, we make use of the statistical randomness of the latent variables to generate synthesized defective samples via the decoder scheme in the trained VAE. Two data representations and VAE modeling strategies, concatenation of multiple and individual raw trace data as the input of the VAE during the training stage, are investigated. A real-data plasma enhanced chemical vapor deposition (PECVD) process having only few defective samples is used to illustrate the performance enhancement to wafer classification arising from the proposed data augmentation framework. Based on the computational comparisons between noted classification models, the proposed generative VAE model via the individual strategy enables the adaptive boosting (AdaBoost) classifier to achieve perfect performances in every metrics if the 80% and 100% over-sampling ratios are adopted. [ABSTRACT FROM AUTHOR]

A novel plasma Charge Accumulative Model (pCAM) by calculating time-integrated Fowler–Nordheim (FN) tunneling charges and field of the gate dielectric in plasma processes is proposed in this paper. Our prior studies have developed and presented a quantitative FinFET plasma recording device by an effective fin-shaped field effect transistor (FinFET) contact-to-metal coupling structure to record and quantify plasma ion charges created in FinFET backend processes. In this paper, a precise analytical model is proposed to model the magnitude of plasma ion charges, time-integrated stressing field, and the criteria of the plasma process for optimum FinFET process technology. The new pCAM is highly matching with the measurement result of 16- and 7-nm FinFET wafers. The model can be adapted to practically estimate the plasma damage with different charge types, process parameters, and ion distribution; it can optimize the FinFET process and further understand the plasma damage mechanism in charging processes of 7-nm FinFET and beyond. [ABSTRACT FROM AUTHOR]

This paper presents the results of studies of dust formations in a radio frequency (RF) discharge plasma. In particular, the behavior of dust clouds in various types of traps was investigated. The experiments were carried out in argon plasma with the following discharge parameters: gas pressure of 0.02–0.6 Torr and discharge power of 1–50 W. Two types of the ring were used as a trap—“closed” and “nonclosed.” It was found that by changing the discharge parameters and using a different type of trap, it is possible to control the capture region of dust formations, and therefore, manipulate the extraction of dust particles by mass (size, in the case of monodispersity of particles). It has been observed that at a lower gas pressure the dust cloud is less affected by the traps; moreover, the wider the edge opening of “nonclosed” ring trap, the more efficient the process of extracting dust particles. The results of this paper can be useful for practical application in the processes of separation and extraction of dust particles from a plasma crystal, the study of particle interactions, and the manipulation of individual particles, etc. [ABSTRACT FROM AUTHOR]

This paper presents a simulation study of the dynamics of dust grains around a small asteroid. Plasma-asteroid interactions and asteroid charging are obtained from fully kinetic particle-in-cell simulations. Dust transport simulation takes into account the electrostatic force, solar radiation pressure, and the gravitational force. Both the result derived from laboratory measurements of regolith surface charging and the single dust charging model are considered for dust charging. For the small asteroid considered in this paper, we find that dust transport is mostly determined by the competition between the electrostatic force and the solar pressure and dust distribution is sensitive to both dust charging and dust grain size. For dust grains in the tens of micrometer size range, the solar radiation pressure dominates dust transport at small dust charge-to-mass ratio, whereas the electrostatic force dictates dust transport at large dust charge-to-mass ratio. [ABSTRACT FROM AUTHOR]

As part of the ongoing China Fusion Engineering Test Reactor (CFETR) studies, this work focused on the study of the electromagnetic (EM) loads distribution on inboard (IB) and outboard (OB) blanket vertical segments. In this paper, a major central disruption scenario with a 36-ms linear current quench was performed in the ANSYS finite element software. EM forces and moments, both on the single module and the complete blanket segment, were calculated for the updated helium-cooled ceramic breeder (HCCB) blanket. Furthermore, the effect of EM loads with respect to poloidal segmentations on the back plate (BP) was studied. Results show that the EM forces and moments in the IB blanket barely changed, but in the OB blanket, great changes occurred. With poloidal segmentations increasing, EM forces loads on the BP will be reduced. This paper may provide important data to support subsequent optimization of the BP of CFETR and could also be a technical reference for other fusion organizations. [ABSTRACT FROM AUTHOR]

Iron nanopowders (Fe-NPs) were extracted and downsized by evaporating the iron powders in an atmospheric microwave plasma flame. The microwave plasma, which was generated by a mixture of nitrogen and argon swirl gases, evaporated the iron powders, immediately downsizing them to Fe-NPs. Subsequently, the Fe-NPs samples were collected by using bar magnets inside the collecting chamber. The Fe-NPs were analyzed by X-ray diffraction, Raman spectroscopy, optical emission spectroscopy, and a scanning electron microscopy. The Fe-NPs consisted of only iron phase and no Fe2O3 or Fe3O4 phases were formed during synthesis. The average sizes of the raw iron powders and the Fe-NPs were approximately $20~\mu \text{m}$ and 20 nm, respectively. The proposed method is simple and easily scalable. Thus, it is suitable for the mass production of Fe-NPs, overcoming the limitations of other catalyst-based synthesis methods. This paper provides a potential method for large-scale production of metal nanopowders which have potential applications in various fields owing to their unique properties at the nanoscale. [ABSTRACT FROM AUTHOR]

This paper clearly demonstrates the structure of Experimental Advanced Superconducting Tokamak (EAST) power supply system and analyzes principles of the finite-state machine (FSM) elaborately. Depending on the characteristics of EAST power supply system and the requirements of it, this paper chooses the real-time Linux as system platform and experimental physics and industrial control system (EPICS) as development tool to design a control system of the EAST poloidal field power system supply. This paper utilizes a temporal logic control based on the FSM in order to regulate the operation process of real-time sequence logic control of 12 sets of power controllers. This design is evaluated and tested, and it completely meets the real-time requirement of the poloidal field power supply (PFPS) control system. Several experiments have proved that this design definitely meets the real-time sequence logic control requirement of the PFPS control system in the complex situations under magnetic fields. [ABSTRACT FROM AUTHOR]

This paper is focused on using plasma as element of a frequency selective surface (FSS). FSSs have been used for filtering electromagnetic waves for many years. Conventional FSSs use metal patch pattern as periodic element. This paper takes the plasma tube as a substitution for metal patch. The 3-D finite-difference time-domain method with periodic boundary condition is utilized to simulate the interaction of incident wave and plasma FSS. Numerical calculation results in that electron number density of plasma can dominate the resonance frequency obviously. The resonance frequency increases as the increasing of electron number density of plasma to the limit of that of perfectly electric conductor. Thus, the FSS can be designed to be tunable by changing the ionized electron number density. Both of the noncollision and collisional plasma model are introduced to study the FSS characteristics. The numerical calculation results show that the collision frequency only influences the reflectivity while has no effect on the resonant frequency. The resonant frequency and transmitted power ratio can be tuned by assigning the plasma’s electron number density and collision frequency. Thus, plasma elements offer the possibility of improved shielding effect along with reconfigurability. Plasma FSS can also be made transparent by tuning the plasma off which makes the use of FSS more versatile. [ABSTRACT FROM AUTHOR]

Basic kinetic process of plasmas is studied by a first principle based N-body simulation. By confirming Coulomb collisional relaxation process, this paper is extended to investigate the dynamics of Debye shielding. Some of the key numerical techniques are discussed, including how to avoid singularities at the near encounter of two charged particles. Electron distribution function in Debye shielding is revealed, which deviates from conventional Maxwellian distribution function. [ABSTRACT FROM AUTHOR]

The values of the propagation constants of electromagnetic (EM) waves through the plasma using as the example of a homogeneous plasma layer for different electron distribution functions (EDFs) are the subject of this paper. The Maxwellian, Druyvesteyn, Pipe-line, and Bi-Maxwellian distribution functions were considered in this paper. Using values of the complex dielectric permittivity obtained from using different EDFs, the results for corresponding reflection, transmission, and absorption coefficients can be significantly different. The EDFs sometimes can have a considerable effect on the dielectric properties of plasma. Hence, comparing the results obtained, it is helpful to analyze the interaction between EM waves and plasma and provide a theoretical basis for the experiments. [ABSTRACT FROM AUTHOR]

The past measurements of the plasma density and potential profiles near the exit of the keeper electrode in a hollow cathode device suggested that turbulent ion acoustic fluctuations and ionization instability in the cathode plume significantly increased the energy of the ions that flow from this region. The lifetime of keeper electrode is limited by sputtering or ion bombardment of the Molybdenum surface exposed to the discharge plasma. Increases in the cathode gas flow reduce the amplitude of the fluctuations and the number and energy of the energetic ions, which decreases the erosion rate of the keeper electrodes. However, as the cathode gas flow is raised for a given discharge current, the performance of a 5-kW Annular-Geometry Ion Engine (AGI-Engine) declines. There is a strong relationship between the performance and the lifetime of the ion thruster. To validate whether the 20-A hollow cathode satisfied China’s communication satellite platform’s application requirement for North-South station keeping, this paper analyzed the effect of the cathode gas flow on the performance and the lifetime of the AGI-Engine. Different from the previous methods, this paper first tracked the movement of energetic ions generated in the plume of the hollow cathode, predicted erosion rates, found where they hit the keeper electrode, and then determined the amount of material that they sputtered. A review of past experimental results was presented first. Next, based on the existing experimental data, theoretical analysis and numerical calculations were performed to determine the optimum gas flow range and the performance curve of the 20-A hollow cathode. The results showed that the primary erosion mechanism of the keeper electrode was caused by impact from Charge Exchange Xenon (CEX) ions, which caused the cathode orifice to be widened and attenuated over time. However, heavy double xenon ($\text{X}_{\text{e}}^{++}$) ions, which struck the keeper electrode more severely than CEX ions, were the most crucial factor that limited the lifetime of the 20-A hollow cathode due to their high energy and large mass. [ABSTRACT FROM AUTHOR]

Linearly polarized spectral emission is induced by non-Maxwellian electrons with anisotropic velocity distributions through collisional processes with ions in plasmas. X-ray line polarization is a viable diagnostic tool for the study of these electrons, which has been tested in controlled settings, e.g., the electron beam ion trap, but due to strong depolarization effects, has been relatively unexplored in laboratory-produced high-energy-density plasmas. This paper explores the X-ray line polarization for the study of Ne-like molybdenum X-pinch plasmas. Previous polarization studies have focused mostly on K-shell spectral lines, whereas the current paper expands on these studies by investigating L-shell line polarization. The X-pinch is favorable due to its high-density plasma formation, high radiation yield, fixed hotspot location, and reliable electron beam production. L-shell X-ray line polarization and spectral emission of Mo X-pinches were investigated through dual $\alpha $ -quartz ($2d=6.687$ Å) crystal spectropolarimetry with axial and radial spatial resolution. In particular, line polarization is evaluated through a comparative analysis of relative line intensities observed over a range of Ne-like Mo transitions simultaneously recorded with two spectrometers with different sensitivity to polarization. An appreciable degree of X-ray line polarization (up to 15%) is observed in the Ne-like Mo plasmas and analyzed using depolarization effects. These results are the first polarization measurements in high-Z pulsed power plasmas. [ABSTRACT FROM AUTHOR]

This paper presents the results of the experiment with an overmassed wire-array $Z$ -pinch load that is powered by a current pulse (amplitude ~4.3 MA and rise time $\sim 0.9~\mu \text{s}$) from a multidisk magnetocumulative generator. Interesting feature of the experimentally recorded soft X-ray (SXR) pulse is short (~10 ns) duration at a microsecond current rise time with total energy of several hundreds of kilojoules. Obtained results are the evidence of high-quality implosion of the current-carrying plasma. The 2-D magnetohydrodynamic code FLUX-rz was used for the numerical simulation and analysis of the obtained results. The calculations indicated that only ~30% of the initial load mass took part in the SXR generation. The main peculiarities of the overmassed $Z$ -pinch implosion are discussed in this paper. [ABSTRACT FROM AUTHOR]

The ITER plasma position reflectometry system will be used to estimate the distance between the position of the magnetic separatrix and the first wall at four predefined locations, complementing the magnetic diagnostics system. The antennas of the system studied in this paper are to be installed between the blanket shield modules of rows 3 and 4, on the high-field side of the tokamak. As the antennas and part of the corresponding waveguides will be directly exposed to the plasma, they will be subjected to high radiation doses from neutrons and gammas, which may cause irradiation-induced changes in the material properties and compromise the integrity of the components. In this paper, the Monte Carlo simulation code MCNP6 and the most up-to-date ITER reference neutronics model were used to estimate the thermal loads in the system. The results, complemented with a finite-element analysis performed with ANSYS Mechanical, show that the nuclear heat loads, combined with the thermal radiation coming from the plasma, translate into operation temperatures that reach 480 °C at the tips of the antennas, slightly above the maximum recommended temperature of operation of stainless steel for ITER in-vessel components under irradiation (450 °C). Further, thermal analyses and design iterations are therefore required to improve the thermal and mechanical behavior of the system. [ABSTRACT FROM AUTHOR]

This paper describes an investigation of plasma influence on the germination rate of brown mustard seeds (Brassica juncea L.). It was found that five pulses of a nanosecond microspark have a suppressing action increasing the time of the seeds germination by 5 h; the plasma influence and UV-radiation of the nanosecond surface discharge with the frequency of 1 Hz for the course of 15 min being at a distance of 25 mm from the surface of the seed have a stimulating action on it reducing the germination time by 3 h; a combined treatment using the discharges of both types showed that germination rate may look as two-pulse mode. Repeated experiments confirmed this conclusion. Visual observation of the seeds after the UV-radiation and plasma treatment revealed cracks on the seed coats. The cracks significantly increase moisture penetration into the coat. [ABSTRACT FROM PUBLISHER]

Atmospheric corona discharge plasmas are the most common diversely occurrence in the electric power system. In this paper, four elementary processes occurred in corona discharge are taken into account, including elastic collision, excitation, attachment, and ionization. As one of the most important parameters in corona characteristics analysis, the effective Townsend ionization coefficient is completely calculated by the Boltzmann equation under the consideration of humidity. This paper also derives the electron energy distribution function (EEDF) in water vapor and dry air, respectively. With reference to previous researches and the existing literature, comparisons and validations on ionization and attachment coefficient are conducted. Besides, the effects of humidity, pressure, and temperature on the effective ionization coefficient are also discussed in this paper. It is concluded that humidity can enhance both ionization and attachment. The results show that the ionization coefficient in this paper is well consistent with traditional ones, while there are variations for attachment coefficient. In normal condition, the effective ionization coefficient varies slightly with humidity, but it increases significantly with a decreased pressure or an increased temperature, which cause the change in critical electric field correspondingly. [ABSTRACT FROM PUBLISHER]

Active flow control by means of plasma actuators has potential advantages over conventional strategies, e.g., mechanical or hydraulic components may be replaced by lightweight, compact, fast response plasma actuators. In this paper, several designs of dielectric barrier discharge (DBD) plasma actuators are presented for aerospace applications and the focus is on the associated feedback control implementation. The interdisciplinary nature of aerodynamic feedback control with plasma, however, makes direct experimental demonstrating an outstanding challenge. Here, we propose a realistic experimental control implementation afforded by commercial off-the-shelf electric products and the major achievement is the detailed instruction (in both electricity and aerodynamics) and the successful demonstration of the closed-loop design in controlling the dominant modes from a cylinder flow setup. The essence of our approach is to drive DBD plasma actuations by a downstream sensor and excite aerodynamic velocity perturbations, which are further amplified on the shear flow from the cylinder, leading to airflow structures, such as vortex roll-up and randomization, which are measured by the downstream sensor to complete the whole loop. We benchmark our control approach by comparing to the predicted dominant frequencies of the controlled flow system, which can be achieved by the Barkhausen stability criterion after establishing the corresponding transfer function of the whole flow control system. Overall, this paper shall assist a host of new applications in aerospace applications in the near future. [ABSTRACT FROM AUTHOR]

For the 3D NAND memory, the higher oxide/nitride (ON) stacked dielectric is preferred to enhance the storage capacity, and multi-layer dielectric requirements, such as thickness uniformity and interfacial smoothness between films, gathers more interest for the performance of 3D NAND flash memory. Unsatisfactory thickness uniformity between layers is a challenge not only for the device performance but also the following etch process steps. The thickness uniformity can get worse with a little facility degradation. The degradation of the vacuum system, such as the throttle valve position, has the potential to cause process drift. This can have an impact on the thickness repeatability of each layer in a multiple dielectric stack. To reduce the process variation in multi-layer dielectric deposition for 3D NAND fabrication, process monitoring, and equipment diagnostic study is suggested in this paper. Optical emission spectroscopy (OES) is employed for plasma process monitoring and equipment state variable identification (SVID) data are investigated to find the source of the process variation. From the comparison experiments of 5 and 30 paired oxide/nitride stack deposition, we found equipment and/or facility degradation may induce the minute process drift. Among them, we suggest the potential of process drift due to the throttle valve position. [ABSTRACT FROM AUTHOR]

The fast development of flip-chip (FC) devices has helped to keep ICs on pace for Moore’s law. FC devices have many buried interfaces, the structures of which all need to be investigated in order to optimize them. It is extremely difficult to examine molecular structures of buried interfaces in samples with multiple layers due to the lack of appropriate analytical tools. In this paper, real FC-on-leadframe devices, manufactured by Texas Instruments Incorporated, were investigated using the intrinsically interface-sensitive technique and sum-frequency generation (SFG) vibrational spectroscopy. By milling down the Si wafer, we can probe the polyimide (PI)/mold compound (MC) interface. By milling down further, we can examine the air/MC and the MC/leadframe (LF) interfaces. Methylene and methyl groups were detected from each of the three interfaces, and the orientation of methyl groups was determined at each interface. It was calculated that at the PI/MC interface, the methyl group tilt angle was 20° (from the surface normal). For the air/MC interface, the tilt angle was 43.5°, and for the LF/MC interface, the tilt angle was measured to be 45°. The deduced different methyl orientations at the two buried solid/solid interfaces can be interpreted by the interfacial interactions. The PI surface is more hydrophobic than the LF surface; therefore, it has more favorable interactions with the hydrophobic methyl groups, leading to a more “standing up” (smaller tilt angle) position for the methyl groups at the PI/MC interface. In this paper, SFG was successfully applied to study the buried interfaces in real devices. The SFG method used in this paper is general and can be applied to other real-world, complicated thick systems. [ABSTRACT FROM AUTHOR]

This paper presents a shutdown dose rate (SDR) calculation to estimate a newly developed preliminary concept of the equatorial port model for the Korean fusion demonstration reactor (K-DEMO). The equatorial port model was designed to provide effective radiation shielding abilities adopting the port shielding block and labyrinth structure, which was integrated into the modified K-DEMO neutronic analysis model by the Monte Carlo automatic modeling system. A rigorous two-step method was applied to couple transport (MCNP) and activation (FISPACT) codes according to three steps of calculation procedures. The results of neutron flux and decay gamma transport calculation for the equatorial port area have been indicated in this paper. The SDR calculation result near the equatorial port area reveals that a dose level in the equatorial port interspace was below $100~\mu $ Sv/h after 12 days of the shutdown. Shielding blocks and two labyrinth structures prove that they effectively attenuate neutrons on the current concept of the equatorial port model. [ABSTRACT FROM AUTHOR]

This paper presents a self-consistent model of plasma polarization around an isolated micrometer-sized dust particle being under the action of an external electric field. It describes ion focusing and wake formation for dust particles with different radii and external electric fields. It is shown that despite the formation of wake, plasma maintains a quasi-neutral condition around a negatively charged dust particle, and the volume charge formed as a result screens the dust particle completely. It is also shown that in the external electric field, the dipole moment of the part of the ion nearest to the dust particle is proportional to the dust particle charge. As the external electric field increases and reaches some threshold value, a positive peak appears in plasma potential downstream of the dust particle. It then increases linearly and shows a broad maximum. [ABSTRACT FROM AUTHOR]

Wrinkle patterns, as a simple surface patterning process, have been previously used in triboelectric nanogenerator (TENG) to improve electric performance. However, since lacking an effective way to control the wrinkle pattern in a wide range, the influence of wrinkle pattern to the performance of TENG has not been systematically investigated. This paper proposes a pre-heating process to adjust the modulus of uncured polydimethylsiloxane, resulting in wide-range controllable wrinkle patterns. Quantitative measurements show the wrinkle pattern wavelength ( \lambda ) could be varied from 20.13 to 0.92~\mu \text{m} by pre-heating time from 0 to 10 min. Using this wide-range wrinkle pattern, the performance of TENG was remarkably improved with a higher surface charge density of 537.6~\mu \text{C}/\text{m}^{2}$ . Through simulating the impact of interfacial structures deformation, we found smaller structure leading to higher performance of TENG at low pressure region and smaller surface area resulting in a lower performance, which accounted for the correlation we observed in this paper, and could guide the structure design for a high-charge-density TENG. This paper provides an alternative way for controlling wrinkle pattern as well as increasing surface charge density of TENG from fabrication process, simulated results, theoretical analysis, and quantitative measurements. [2017-0154] [ABSTRACT FROM PUBLISHER]

The pseudospectral analytical time-domain (PSATD) particle-in-cell algorithm solves the vacuum Maxwell's equations exactly, has no Courant time-step limit (as conventionally defined), and offers substantial flexibility in plasma and particle beam simulations. It is, however, not free of the usual numerical instabilities, including the numerical Cherenkov instability, when applied to relativistic beam simulations. This paper presents several approaches that, when combined with digital filtering, almost completely eliminate the numerical Cherenkov instability. This paper also investigates the numerical stability of the PSATD algorithm at low beam energies, drawing in many cases on the pioneering work of Prof. Ned Birdsall, in whose memory this paper is dedicated. [ABSTRACT FROM PUBLISHER]

According to Internationa Thermonuclear Experimental Reactor (ITER) integration procurement arrangements, the installment of diagnostics in a port should not increase the shutdown dose rate (SDDR) in the port interspace area by no more than \sim50~\muSv/h above the baseline, assuming another 50 \muSv/h is attributed to contribution from the port structure and other ITER in-vessel components, such that the upper SDDR limit of 100 \muSv/h is not exceeded 10^6~s after shutdown. It was found that placing the initial design of the motional stark effect (MSE) and the charge exchange recombination spectroscopy (CXRS) in the equatorial port #3 resulted in an increase in the SDDR that far exceeded the limit. When we follow the optimization process discussed in this paper, substantial reduction in the port interspace SDDR was achieved. The results of this paper show that even when we combine the optimized CXRS and MSE diagnostics with a third glow discharge diagnostic, the excess of the SDDR over the baseline value did not exceed the allowed upper limit. This paper is based on utilizing the 3-D CAD-based ATTILA code for assessing the SDDR. [ABSTRACT FROM PUBLISHER]

For an advanced NAND flash memory device, there is a failure mechanism known as “blown gate oxide” that is commonly sourced to the plasma-enhanced chemical vapor deposition (PECVD) amorphous carbon deposition step. It has been observed that specific maintenance events on the PECVD process chambers will trigger this failure mechanism, most significantly when replacing the showerhead, or installing a “poor quality” showerhead. This paper investigates utilizing surface photovoltage measurements to indicate when a chamber has a high probability to cause blown gates. In this expanded edition of this paper, we also investigate issues concerning chamber cleaning cycles and how they were resolved. [ABSTRACT FROM AUTHOR]

The microwave plasma torch (MPT) is an attractive plasma source in both industry and scientific research because of its advantages in electrodeless operation ability, high energy efficiency, and flexibility under different operational conditions. However, relatively few numerical studies have been carried out for the MPT fed by a rectangular waveguide in two or even three dimensions. Therefore, this paper presents a 2-D, axisymmetric, and stationary fluid models to characterize the MPT, with an emphasis on the mechanism of the surface wave formation and the sustentation of the plasma column. Nine partial differential equations are included in this research, coupling microwave radiation, heat transfer, plasma bulk flow, and transport of different species with each other. The obtained results reveal how the traveling surface wave occurs and elucidate the consequent influence of the surface wave formation. Furthermore, this paper demonstrates the extension of the plasma column length and the propagation of the surface wave with an increase in the total plasma-absorbed microwave power. The dependence of the plasma column length on the plasma-absorbed microwave power is found to be motivated by the surface wave propagation. The limitations of the model and the difficulties in its numerical implementation are also discussed in the paper. [ABSTRACT FROM PUBLISHER]

A bond-pad charging protection design for charging-free reference transistor test structures was examined. This paper concludes that truly charging-free reference transistors cannot be realized with the one conventional bond-pad charging protection design of protecting transistor gates only. This, however, can be achieved by simultaneously protecting all terminals of the reference transistors. The simulations, in this paper, reconfirm the earlier important experimental conclusion that placing protection device(s) at transistor gates may inflict severe damage to transistor gate oxides instead of protecting them. The implication of the above suggests that attention may be required in a circuit layout design stage for those transistors which gates begin to connect, at high metal layers, to highly efficient leakage paths, such as protection devices, n-type source/drain diffusion regions, and VSS bus lines, which tend to pull transistor gates to low potentials during a backend integrated-circuit manufacturing process. This paper proposes an optimum bond-pad charging protection design for the truly charging-free reference transistor test structures by considering a minimum usage in a layout space and minimum gate oxide stress in the fuse zap-off process. [ABSTRACT FROM AUTHOR]

Risk of arcing in space plasma environment on satellite solar panel has always been an issue of major concern in the aerospace community. The outcome of round robin tests performed in various laboratories has resulted in finalization of the guidelines for the ground test of satellite solar panel coupons (SSPCs). This is documented as ISO-11221 standards. Authenticity of arc plasma flashover (FO) parameters are still under debate. Some experimental findings that support the perimeter theory of arc FO on geostationary (GEO) satellites are discussed in this paper. It has been observed that characteristics of an the arc are dependent on its location on the solar coupon, bias charge (charge due to bias voltage and external capacitance), and the total charge dissipated during the arc discharge. It is also observed that the duration between the two consecutive arcs is directly proportional to the dissipated charge or energy of the latter arc. A combined dielectric consisting of solar cell, adhesive, Kapton, and Carbon Fiber Reinforced Polymer sheet holds charge during irradiation by the electron gun. This resembles surface FO capacitance. Arc energy is governed by the combined effects of a surface flashover capacitor (C-sf) and an external capacitor. It is observed that if intermittent arc duration is sufficiently longer than the gradual accumulation of charge on the SSPC, body may lead to a major arc. This would increase the probability of secondary arcs when the sustained arc environment is experienced by the satellite. To understand primary arcs on dielectrics, an artificial triple junction is prepared and exposed under adverse GEO-like space conditions. Various signatures identified from the arc current and arc neutralization current waveforms specify the behavior of these arcs at different locations on the coupon surface. In this paper, current waveforms of arcs captured on different types of solar panel coupons and their significance are studied. Information about arc energy, arc velocity, and neutralization velocity are extracted from the measured waveforms. [ABSTRACT FROM PUBLISHER]

This paper considers thermal neutralized charge electron flux moving through immovable static ion background. A 2-D dispersion equation is derived. The equation describes linear waves of space charge (WSC) in the flux. In the result of the dispersion equation analysis, we proved the existence of the backward and sideward WSCs. Maps on the plane $\{{k_{x}; k_{y}} \}$ were calculated and plotted for two values of the electrons drift velocity. The lines on those maps correspond to the direct, sideward, and backward WSCs. Areas of obtuse and acute drift angles are marked out. [ABSTRACT FROM AUTHOR]

In this paper, we report a qualitative model of operation and energy release in pulsed dielectric barrier discharges (DBDs). We demonstrate that pulsed DBDs operate according to the “maximum power principle” and explain the relevant physical processes. Compared to experimental data, the proposed model allows an accurate estimation of the discharge pulse energy as a function of dielectric properties, electrode size, and pulse parameters (shape and voltage amplitude). [ABSTRACT FROM AUTHOR]

The front plates and embedded particle sensor shells that are part of the electric field instrument (EFI) on the Swarm satellites have recently been used as planar Langmuir probes, as an additional diagnostic tool to infer environment parameters. The interpretation of measured currents in terms of the plasma density or incoming flow speed, however, requires a knowledge of the front plate effective cross section $A_{\textrm {eff}}$. Measurements made under various space plasma conditions have led to the conclusion that this cross section is generally larger than the known geometrical cross section $A_{\textrm {geo}}$. Interpretations of measurements have thus been made using fixed relative enhancements of $A_{\textrm {geo}}$ ranging from 8% to 17%. In this paper, results from kinetic simulations are presented, from which the effective cross section can be determined over a range of plasma parameters. These are used to shed light on the physical mechanisms responsible for this enhancement and construct an empirical fit to the relative enhancement $\delta $ , where $A_{\textrm {eff}} = A_{\textrm {geo}}(1 + \delta)$ , and, in turn, enable improvements in the accuracy of inferred plasma parameters. [ABSTRACT FROM AUTHOR]