Bulletin of the American Physical Society
73rd Annual Gaseous Electronics Virtual Conference
Volume 65, Number 10
Monday–Friday, October 5–9, 2020; Time Zone: Central Daylight Time, USA.
Session RW3: Poster Session V (4:30pm - 6:30pm)On Demand
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RW3.00001: Analysis of temperature distribution affected by oblique opening in high-pressure air circuit breaker Shinichiro Kashiwagi, Zhenwei Ren, Yusuke Nemoto, Yoshifumi Maeda, Toru Iwao In recent years, deterioration of the global environment, especially global warming, has been highlighted as an urgent problem. For this reason, environmental measures to prevent global warming are being promoted in each industrial field. Efforts such as reduction of SF6 gas emission are progressing, and environmentally friendly product development is required for each equipment. Focusing on the high-pressure air circuit breaker, it is important to understand the basic characteristics of the arc generated between the electrode contacts in order to achieve miniaturization and higher performance. However, the simulation analysis of oblique opening in the high-pressure air circuit breaker are very few reports. In this paper, we calculated the arc temperature distribution during oblique opening in the high-pressure air circuit breaker using the 3-D electromagnetic thermal fluid simulation. Specifically, we conducted an unsteady analysis in which the movable contact moved diagonally over time. As a result, the asymmetric temperature distribution was calculated by the diagonal opening. [Preview Abstract] |
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RW3.00002: Pulsed plasma ice drilling for Mars' polar layered deposits Xin Tang, Jacob Mallams, Matthew Burnette, Cameron Adkins, Tyler Barnes, David Staack, Fernando Mier-Hicks, Guglielmo Daddi, Gareth Meirion-Griffith Hot-tip melt-probes for accessing Mars' polar layered deposits (PLD) are highly inefficient due to heat conductive losses. A pulsed plasma ice drilling method is utilized to explore the possibility of cracking ice to reduce the heat loss since cracked or granular ice has a lower thermal conductivity. Plasma discharges with different pulse energy under atmospheric pressure with two electrodes embedded on a clear ice plate demonstrates the area-of-influence based on the cracked area. A transient needle probe is employed to quantify the change in thermal conductivity of granular ice created by pulsed plasma. This is compared to various granular ice size distributions separated by a sieve shaker to explore the relationship between the ice granular size and the thermal conductivity of powdered ice, which will then determine the pulsed plasma discharge targeted cracking parameters, such as number of discharges, energy per pulse, input power, etc. Different arrays consisting of spark gaps in parallel and series are tested both in air and in ice for potential hybrid conceptual design. The incorporation of hot-tip probes with this pulsed plasma method will improve the rate of penetration inside ice deposits during interplanetary missions with limited solar power access. [Preview Abstract] |
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RW3.00003: Characterization of a commercial plasma source for plasma etching of substrates Dereth Drake, Bakari Bethea, Arthur Bui, Eric Burns, Zachary Barton, Gabriella Miles, Ashley Raulerson Plasma etching and cleaning is very common in the electronics fields. Since the 1970s, the use of etching has become standard in the development of substrates for microelectronics. Recently a number of commercial plasma etching systems have been introduced to the market. However, the systems are not commonly used in industry or in academia since there effectiveness has not be adequately verified in the literature. In this poster, we present spectroscopic measurements of the plasma produced by a commercial plasma etching system in an effort to start this verification process. [Preview Abstract] |
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RW3.00004: Evaluation of absolute charge density at the bottom of hole pattern using high aspect ratio capillary plate Makoto Moriyama, Naoya Nakahara, Haruka Suzuki, Hirotaka Toyoda In recent years, high aspect ratio hole etching by reactive ion etching (RIE) using capacitively coupled plasma (CCP) has become extremely difficult in the fabrication of 3D NAND memory devices. Particularly, abnormal profiles caused by ion orbital deflection due to positive charge-up inside the hole pattern is a great issue. To solve this, it is important to understand ion behavior inside the hole and the charge-up mechanism. In this study, high frequency voltage at the bottom of the hole patterns on the CCP cathode electrode is measured to evaluate the absolute density of the positive charge accumulated at the hole bottom. A lead-glass capillary plate with an electrode on the bottom, as a model of hole pattern, is placed on the cathode via an insulated alumina plate. Voltage on the plate bottom is measured using a high-voltage probe inserted through an isolated and vacuum-sealed feedthrough. The charge density is evaluated from a one-dimensional equivalent circuit model using the measured voltage, plasma potential and the plate capacitance. [Preview Abstract] |
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RW3.00005: Structure control of self-supporting graphene nanowalls synthesized by plasma enhanced chemical vapor deposition Keigo Takeda, Motoaki Ishikawa, Mineo Hiramatsu, Hiroki Kondo, Masaru Hori Carbon nanowalls (CNWs) composed of few-layer graphenes grown vertically on a substrate form self-supporting network of walls. The large surface area of conductive carbon with high chemical and physical stability is useful for electrochemical applications, such as sensing, rechargeable battery cell, etc. For achieving such applications, the structure control of CNWs is one of crucial issues. The structure of CNWs is considered to depend on the surface density of nucleation on the substrate in the initial growth of CNWs. In this study, the CNWs growth was carried out using two-step plasma CVD process with different conditions for the initial growth of CNWs as a template and the subsequent vertical growth after the initial growth. The CNWs were grown on a Si substrate by an inductively coupled methane/Ar plasma CVD. As results, surface morphology and crystallinity of grown CNWs became denser and lower with increase in the Ar flow rate ratio of methane/Ar mixture. However, by reducing the Ar flow rate ratio after the initial growth under the high Ar flow rate ratio condition, vertical-grown CNWs with relatively large interspace between adjacent nanowalls could be synthesized with high crystallinity. [Preview Abstract] |
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RW3.00006: P2I: A code for modelling Plasma Ion Implantation Michael Bradley, Marcel Risch Plasma Ion Implantation (PII) is a technique in which a solid target immersed in a plasma is implanted with energetic ions via the application of a pulsed kilovolt-level negative bias voltage. PII allows implantation of very high ion fluences across broad-area targets. This makes it an ideal technique for many applications, including semiconductor device fabrication. When using PII, it is important to accurately model the implantation current, to ensure good fluence control for materials applications. This talk will describe the P2I code developed our group for this purpose, as well as some applications. [Preview Abstract] |
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RW3.00007: Influence of applied voltage amplitude on chemical reaction locus in a plasma-enhanced packed bed reactor Zaka-ul-Islam Mujahid, Mohammed Oteef, Ahmed Hala, Xin Tu, Julian Schulze Plasma enhanced packed bed reactors (PE PBR) are promising for VOC abatement applications. Previous studies have reported that applied voltage (or power) is an important parameter with regards to PR PBR's performance. However, the origin of this change in performance is not well understood. PE PBR has multiple micro and mesoscopic voids/cavities where the plasma is generated. The ICCD images showed that the plasma emission position changes with the applied voltage amplitude. The reactants and the products in a PE PBR are typically in gaseous or in liquid form, and therefore the position of the chemical reactions in the cavity could not be studied. In this work, we have tailored operating conditions to enhance the production of solid or liquid products deposited at the location of the chemical reaction. It was found that the chemical reactions happened predominantly at the position of plasma emission in these conditions. Similar to the plasma emission, the reactive species deposition position changes with the applied voltage amplitude.~ The analysis of the expected reactive species life times, reaction products and deposition location indicate that short duration species such as OH and O possibly play an important role in VOC conversion. [Preview Abstract] |
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RW3.00008: Temperature Dependence of Al$_{\mathrm{2}}$O$_{\mathrm{3}}$ Ablation Plume on Ambient Pressure and Laser Intensity by Laser Diode toward Lunar Regolith Utilization Kazune Uesugi, Ryohei Oishi, Makoto Matsui Among the lunar surface regolith, alumina is confirmed to be present in about 10{\%} in the whole moon, especially in the highlands about 23{\%}, which is one of the representative substances. Although alumina itself is not a very versatile material, reduced aluminum has a lot of applications for future lunar activities including a base construction. The laser ablation is one of the promising reduction methods because it does not require reducing agency. In this study, we investigated the temperature dependence of the ablation plume on ambient pressure and the laser intensity using 1 kW class continuous-wave diode laser. As a result, the plume temperature increased with the ambient pressure and the laser intensity in the range of 3500 K to over 5500 K. [Preview Abstract] |
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RW3.00009: Plant growth promotion using radical-activated L-alanine solution Ginji Ito, Naoyuki Iwata, Hiroshi Hashizume, Masaru Hori, Masafumi Ito Recently, biological applications of atmospheric-pressure plasmas have been studied. In particular, the promotion of plant growth using non-equilibrium plasmas has attracted much attention as an inexpensive and safe method without chemicals. Previously, we reported that the radical treatment of phosphate buffer solutions containing L-phenylalanine simultaneously showed bactericidal and plant-growth-promotion effects, and the length of radish sprouts was promoted nearly two times. In this study, L-alanine, which has a very similar structure to L-phenylalanine but without the benzene ring, was treated by radical irradiation to find an important chemical structure in L-phenylalanine for the plant-growth promotion. The experiments were performed in a similar manner to those in the previous study. 20 germinated radish sprouts were cultured in the radical-activated L-alanine solutions for 48 h at a temperature of 22 ${^\circ}$ and a humidity of 60 {\%} using an artificial environmental controller. Subsequently, the lengths of radish sprouts were measured. As a result, there was no significant promotion of sprouts, and therefore the benzene ring structure of L-phenylalanine was found to be an important factor in the plant-growth-promotion effect of radical-activated L-phenylalanine. [Preview Abstract] |
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RW3.00010: Apoptosis-inducing activity through caspase pathway in melanoma cells treated by radical-activated lactate Ringer's solution Yuki Hori, Tomiyasu Murata, Hiromasa Tanaka, Masaru Hori, Masafumi Ito It has been reported that plasma-activated lactate Ringer's solution (PAL) can selectively inactivate various cancer cells. However, it has not been clarified which factor of plasma such as neutral radicals, charged species and optical radiation activates solutions and influences the viability of cancer. To investigate the individual contribution of these species, we have developed an atmospheric-pressure radical source which can selectively expose neutral radicals without other species in the plasma. The radical source was driven with Ar, O$_{\mathrm{2}}$ and N$_{\mathrm{2}}$ whose flow rates were set at 1.40, 0.51 and 0.09 slm. lactate Ringer's solution using the radical source and melanoma cancer cells (B16-F10) were incubated in radical-activated lactate (RAL) solution and the cell viability was measured using MTS assay. As a result, cells were effectively inactivated using RAL. Also, the activity of caspase-3, known as a mediator of apoptotic death, in the treated melanoma cells was measured. The activity of caspase-3 in melanoma treated with RAL was 24 times higher than that treated with radical-untreated lactate solution. These results suggest that neutral radicals are effective factors for the anti-cancer property of PAL and the apoptosis was induced in melanoma cells via caspase pathway. [Preview Abstract] |
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RW3.00011: Operation of a cylindrical Hall thruster with externally driven breathing oscillations Jacob Simmonds, Yevgeny Raitses, Andrei Smolyakov, Oleksandr Chapurin We report results of experimental and numerical studies of the effect of externally-driven voltage modulations on the operation and performance of a low power 2.6cm cylindrical Hall thruster with permanent magnets. For simulations, a one-dimensional hybrid code HALLIS [1] is used. Both experiments and simulations demonstrate that the effect of voltage modulations on the thruster discharge has a resonant-kind behavior. For example, the discharge current and the ion current reach their maximum values when the frequency of modulations approaches the frequency of the breathing oscillations [2]. Thrust measurements revealed a frequency-dependent increase in thrust, with the maximum thrust occurring when modulating at the natural breathing frequency. It follows from plasma measurements in the thruster plume that this thrust increase is due to an increase in average ion energy, as the oscillations of ion energy and ion current were shown to be in phase at the resonance condition. Simulations show these improvements occur when the ionization wave is amplified through increased electron temperature, which were verified by experimental measurements. [1] J. P. Boeuf, J Appl. Phys. 121, 011101 (2017); [2] Romadanov, I. et al., Plasma Sources Sci. Technol. 25, 011604 (2018) [Preview Abstract] |
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RW3.00012: Use of a Reactive ion etch plasma system for conversion of thin salt infiltrated polymer films to metal and metal oxide layers Jim Conway, Matthew Snelgrove, Ross Lundy, Pravind Kumar Yadav, Miles Turner, Stephen Daniels Thin polymer films (< 10 nm) can readily be deposited on substrates. Conversion of the polymer film to metal or metal oxide films can be achieved by infiltrating the polymer with metal salt and exposing the resulting film to plasma. Radicals and reactive ions from the plasma can remove both polymer and anionic groups from the salt leaving a metal layer. In Asymmetric Capacitive Plasma systems RF power controls the radical density and also ion density and energy. Increasing RF power to create more radicals also increases ion interaction at the surface and may completely remove the metal layer. Reductive processes using H2 can result in a metal layer at the surface. O2 plasma on the other hand can convert the metal layer to metal oxide. Al salt and Zr salts were used to infiltrate P2VP-OH polymer films and plasma was used to produce thin films whose nature depended on the plasma. XPS analysis was used to monitor the chemical nature of the resulting films. [Preview Abstract] |
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RW3.00013: Abstract Withdrawn
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RW3.00014: Influence of plasma treatment on seed germination, growth and stress tolerance Taeib Tounekti, Mukul Sharma, Majid Hamad, Zaka ul Islam Mujahid, Habib Khemira The influence of plasma treatment on seed germination properties has been widely studied. However, the response to plasma treatment is not consistent on different species. In this work, we have selected three types of seeds i.e. wheat and sorghum, acacia and grape; to treat them with plasma in comparable conditions. These treatments effects on weight loss, water absorption, germination and stress tolerance were studied. The results show that plasma treatment reduced the weight and improved water absorption in all seeds. The optimum plasma treatment improved the germination of seeds, best in grape seeds, then in acacia and least in wheat and sorghum. In acacia the plasma treatment has comparable improvement to the conventional acid bath. In grape seeds the plasma treatment even increased germination \textasciitilde 50 {\%} compared to chilling. The mechanism of these improvements was discussed in terms of the type of seed dormancy, seed structure, antioxidant systems and stress tolerance. It appears that plasma treatment etches the surface of the seeds thus facilitating imbibition and causes oxidative stress, which significantly improves the germination of grape and acacia seeds. It can be concluded that the response of seeds to plasma treatment depends on their mechanical and physiological properties. [Preview Abstract] |
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RW3.00015: Compact torus plasma experiments for high specific impulse pulse plasma thruster Tao Lan, Chen Chen, Sen Zhang, Ge Zhuang, Defeng Kong, Chijin Xiao, Wandong Liu A new compact torus plasma system (USTC-CT) is developed as a gas pulse plasma thruster (PPT) prototype with very high specific impulse in University of Science and Technology of China (USTC). The USTC-CT is a three-meter long linear device and equipped with two main high voltage power supplies. It is composed of the vacuum vessel, central solenoid, fast gas valves, timing system, pulse power supplies and compact torus (CT) exclusive diagnostics. The CT plasma is generated in the formation region with high voltage up to 10kV and then the self-organized CT plasmoid is axially accelerated to very high speed with strong Lorentz force in the acceleration region. Currently, the single pulse USTC-CT is in the engineering commissioning. The maximum particle number of single CT pulse is 10$^{\mathrm{20}}$ for helium. The maximum electron density and axial speed are 1x10$^{\mathrm{22}}$m$^{\mathrm{-3}}$ and 150 km/sec, respectively. Correspondingly, it provides the high specific impulse of 10$^{\mathrm{4}}$sec and the directional momentum of 0.1 N sec. The remarkable results show the CT PPT has great potential for the space electric propulsion. [Preview Abstract] |
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RW3.00016: Abstract Withdrawn |
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