Article
Physics, Fluids & Plasmas
Tanubhav Srivastava, Marien Simeni Simeni, Gaurav Nayak, Peter J. Bruggeman
Summary: This study investigated self-organization at the plasma-liquid anode interface, revealing significant impacts of factors such as electrode gap distance, solute, and gas composition on pattern formation. A key underlying mechanism was proposed to explain all experimentally observed trends.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2022)
Article
Physics, Fluids & Plasmas
Yao E. Kovach, Maria C. Garcia, John E. Foster
Summary: This study aims to elucidate the nature of plasma self-organization through experimental research on the patterns formed on liquid anode surfaces with 13 different electrolytes. The observed pattern characteristic length scales ranged from 2 to 13 mm and typically increased with current, with complex self-organized patterns observed that have not been reported to date. The parameters associated with pattern formation and morphology complexity are discussed and summarized.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2021)
Article
Physics, Fluids & Plasmas
Prashant K. Barnwal, A. Ganguli, R. Narayanan, R. D. Tarey
Summary: This study provides a detailed characterization and analysis of plasma formation in a planar DC discharge system using different anode sizes. It is found that discharge systems with a conducting boundary require lower voltages with little variation, while systems with a small volume insulated boundary require higher voltages with considerable variation.
PHYSICS OF PLASMAS
(2022)
Article
Computer Science, Information Systems
Shixin Zhao, Xingbao Lyu, Yangguo Liu, Chengxun Yuan, Svetlana Avtaeva, Anatoly Kudryavtsev, Xiaoxue Li, Jingfeng Yao, Ying Wang, Zhongxiang Zhou
Summary: The characteristics of post-cathode plasma in a self-made DC short glow-discharge plasma generator with grid electrodes were measured using optical emission spectroscopy. The discharge operated in an abnormal glow discharge mode at a voltage of 250-400 V, a helium pressure of 3-15 Torr, and a discharge gap of 3 mm. The results showed that the intensity distribution of helium atom spectral lines differed between the post-cathode and post-anode spaces, and the temperature of electron excitation in the post-cathode plasma reached a peak of 1500-3000K at a distance of 5-6 mm from the grid cathode.
Article
Chemistry, Analytical
Krzysztof Greda, Maja Welna, Anna Szymczycha-Madeja, Pawel Pohl
Summary: By combining ICP OES with a novel FIGA mode, a more sensitive determination of Hg was achieved. The proposed method showed a much higher analytical signal for Hg compared to conventional PN-ICP OES, resulting in a significantly improved detection limit (0.035 μg/L) and measurement precision (2.5%). It also offered a 4 times lower detection limit compared to CVG-ICP OES (0.15 μg/L).
Article
Nanoscience & Nanotechnology
Sohaib Raza, Chandrakant Kumar Nirala
Summary: A 2D axisymmetric plasma model was developed for micro-electrical discharge machining (μEDM), focusing on the discharge phenomenon. The simulation of plasma properties variations helps to explain the discharge process comprehensively and determine the heat flux. Anode spot responsible for material removal was observed to form much earlier during the discharge initiation.
Article
Physics, Multidisciplinary
Dibyajyoti Bora, Aritra Tarafder, Subir Biswas, Malay B. Chowdhuri, Joydeep Ghosh
Summary: A uniform and quiescent laboratory plasma was produced without using any magnetic field using a filament-assisted DC source. The plasma was generated by accelerating thermionically emitted electrons along the length of the chamber with the help of a biased stainless steel grid. Langmuir Probe measurements confirmed the spatially uniform plasma generation with specific plasma parameters.
Article
Engineering, Environmental
Chengyuan Duan, Manabu Tanaka, Masahiro Kishida, Takayuki Watanabe
Summary: The translation discusses the experimental results and decomposition mechanism of highly-concentrated pyridine treatment using a novel mist-type water thermal plasma torch. The results show efficient decomposition of pyridine, producing valuable gas products and a small amount of liquid by-products. Water plasma demonstrates significant potential in treating non-biodegradable industrial liquid waste.
JOURNAL OF HAZARDOUS MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Ahmad Hamdan, Luc Stafford
Summary: Discharge in liquid is a promising technique for producing nanomaterials through electrode erosion. However, the production of nanoalloys through in-liquid discharges remains challenging. In this study, nanoalloys of Ni-Fe, Ni-Co, Co-Fe, and Ni-Co-Fe were successfully synthesized through spark discharge in liquid cyclohexane. The results offer new pathways for producing a wide range of nanoalloys.
Article
Physics, Applied
Peter J. Bruggeman, Renee R. Frontiera, Uwe R. Kortshagen, Mark J. Kushner, Suljo Linic, George C. Schatz, Himashi Andaraarachchi, Stephen Exarhos, Leighton O. Jones, Chelsea M. Mueller, Christopher C. Rich, Chi Xu, Yuanfu Yue, Yi Zhang
Summary: Plasma interacting with liquids can generate a highly reactive liquid layer, enabling selective, efficient, and green chemical transformations and new material synthesis. PDSE can be seen as replacing a metal electrode in an electrolytic cell with a gas phase plasma, which is crucial for driving transformational advances in PDSE.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Engineering, Chemical
Dmitriy A. Shutov, Kristina Smirnova, Alexander N. Ivanov, Vladimir V. Rybkin
Summary: The formation of precipitation in a copper nitrate solution under the action of direct current atmospheric pressure discharge was investigated. Turbidimetry kinetic measurements revealed the process involves two stages, resulting in the formation of monoclinic CuO crystals.
PLASMA CHEMISTRY AND PLASMA PROCESSING
(2022)
Article
Chemistry, Physical
Jing-Lin Liu, Tong Hui Zhu, Bing Sun
Summary: A novel kinetic model was developed to understand the chemical nature of fuel reforming in liquid phase discharge. The model was verified by experimental results for ethanol reforming in microwave discharge plasma in liquid. The key reactive species in the liquid phase discharge were identified, and the rate determining steps for ethanol conversion were revealed. The kinetic control mechanism for ethanol reforming in liquid phase discharge was determined, and the energy transfer pathway for discharge power to chemical energy was simulated. A competitive energy efficiency of -85% for ethanol reforming was achieved in the liquid phase discharge.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Engineering, Chemical
Mikhail Vasilev, Patrick Conlon, Douglas Bohl, Selma Mededovic Thagard
Summary: This study investigates the effects of discharge frequency on the degradation of organic compounds in a gas-liquid plasma reactor. It is found that the discharge frequency controls the compound degradation via multiple mechanisms. The results of this study have significant implications for the design of chemical reactors in water treatment applications.
PLASMA CHEMISTRY AND PLASMA PROCESSING
(2022)
Article
Engineering, Chemical
Dmitriy A. Shutov, Kristina V. Smirnova, Alexander N. Ivanov, Vladimir V. Rybkin
Summary: The kinetics of the formation of hydrogen peroxide, nitrite and nitrate ions, as well as pH changes, were studied in an aqueous liquid anode under the action of a direct current discharge. A 0-D model consisting of two sub-models was used to describe and analyze the results. The sub-model of the discharge was based on the self-consistent solution of the Boltzmann equation and the equations of chemical kinetics, while the sub-model of the solution included 28 components and 119 reactions. The concentrations of NO2-, NO3-, and pH obtained from calculations agreed with experimental results within the limits of accuracy.
PLASMA CHEMISTRY AND PLASMA PROCESSING
(2023)
Article
Engineering, Aerospace
Aleksandr A. A. Firsov
Summary: This paper presents the testing and optimization results of a plasma-assisted combustion scheme using a fuel injection pylon equipped with a plasma actuator. Experiments were conducted using ethylene as fuel under specific conditions, and two new geometries of the pylon with electrodes were proposed and tested. The results show stable ignition and intense combustion in difficult conditions, as well as a reduction in energy input compared to previous configurations.
Article
Optics
Abdullah Zafar, Elijah Martin, Steve Shannon
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2019)
Article
Physics, Applied
D. J. Peterson, K. Ford, J. Brandon, S. C. Shannon, T. Koh, T. C. Chua, K. Bera, W. Tian, S. Rauf, P. A. Kraus
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2020)
Article
Physics, Applied
Chenhui Qu, Steven J. Lanham, Steven C. Shannon, Sang Ki Nam, Mark J. Kushner
JOURNAL OF APPLIED PHYSICS
(2020)
Correction
Physics, Applied
Chenhui Qu, Steven J. Lanham, Steven C. Shannon, Sang Ki Nam, Mark J. Kushner
JOURNAL OF APPLIED PHYSICS
(2020)
Article
Nuclear Science & Technology
Alexander Lindsay, Roy Stogner, Derek Gaston, Daniel Schwen, Christopher Matthews, Wen Jiang, Larry K. Aagesen, Robert Carlsen, Fande Kong, Andrew Slaughter, Cody Permann, Richard Martineau
Summary: Efficient solution of nonlinear systems of equations using Newton's method requires an accurate representation of the Jacobian, and automatic differentiation (AD) can provide this with guaranteed accuracy at a relatively low cost. This approach is beneficial for complex systems arising from spatial discretization of partial differential equations in multiphysics settings.
NUCLEAR TECHNOLOGY
(2021)
Article
Physics, Fluids & Plasmas
D. Peterson, Y. Xiao, K. Ford, P. Kraus, S. Shannon
Summary: The electron temperature in a pulsed capacitively coupled argon plasma at 400 mTorr is measured using a time resolved hairpin resonator probe. The effective collision frequency is related to the electron energy distribution through the effective conductivity, allowing for the determination of electron temperature. Results generally show good agreement with expected behavior and unfiltered time-resolved optical emission measurements.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2021)
Article
Materials Science, Coatings & Films
Yuhua Xiao, Yao Du, Carl Smith, Sang Ki Nam, Hoki Lee, Jang-Yeob Lee, Steven Shannon
Summary: This article discusses the use of capacitively coupled wafer-bearing cathodes in etching and deposition processes, as well as the importance of focus rings at the edge of the wafer. Experimental results show that the focus ring acts as a voltage divider in high voltage cases, but the sheath voltage drop over the focus ring increases in low voltage cases.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2021)
Article
Physics, Applied
Carl L. Smith, Sang Ki Nam, Kiho Bae, Jang-Yeob Lee, Steven Shannon
Summary: This study presents the development of an integrated global plasma-circuit model that combines transient plasma model with a broader circuit model to capture the behavior of the power delivery system. Experimental data indicate that negative feedback mechanisms in the early power on cycle increase the magnitude of reflected power.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Materials Science, Coatings & Films
Yao Du, Florian Kruger, Sang Ki Nam, Hoki Lee, Suyoung Yoo, Jacob Eapen, Mark J. Kushner, Steven Shannon
Summary: In plasma etching for microelectronics fabrication, the interaction between ions and sidewalls has a significant impact on the shape of features. This study uses molecular dynamics simulations to investigate the glancing-angle scattering of argon ions from different materials. The results reveal that the scattering characteristics are influenced by the angle and energy of the incident ions, with polystyrene showing more diffuse scattering compared to amorphous carbon and SiO2.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2022)
Article
Physics, Applied
Joshua Morsell, Naman Bhatt, Corey Dechant, Steven Shannon
Summary: Surface ionization waves (SIWs) propagating along dielectric covered, grounded surfaces were studied for different dielectric conditions. The propagation velocity of SIWs depends on the dielectric electrical thickness and near surface permittivity profiles. It was found that the approximation relating the SIW velocity to the RC time constant breaks down for dielectric substrates of sufficient thickness, where the wave velocity becomes constant. The thickness dependent behavior of SIW propagation is driven by both the dielectric material near the surface and the bulk material.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Materials Science, Coatings & Films
Yuhua Xiao, Joel Brandon, Joshua Morsell, Sang Ki Nam, KiHo Bae, Jang-Yeob Lee, Steven Shannon
Summary: Capacitively coupled plasmas are widely used in semiconductor processes. However, controlling plasma uniformity near the substrate edge is still a challenge. This study proposes a combination of a focus ring and a tunable external circuit to extend the plasma uniformity to the wafer edge. The adjustable external circuit can control voltage distribution and improve plasma density and edge profiles.
JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A
(2023)
Article
Physics, Fluids & Plasmas
Corey DeChant, Casey Icenhour, Shane Keniley, Alexander Lindsay, Grayson Gall, Kimberly Clein Hizon, Davide Curreli, Steven Shannon
Summary: Compared to other computational physics areas, the verification methods for plasma fluid codes are not well-documented. Current analytical solutions for plasma are limited due to the assumptions needed. This study suggests using the method of manufactured solutions (MMSs) for future verification efforts and highlights the flexibility of MMS in verifying highly coupled systems. The MOOSE framework was utilized to demonstrate the effectiveness of MMS in plasma fluid code verification.
PLASMA SOURCES SCIENCE & TECHNOLOGY
(2023)
Article
Computer Science, Interdisciplinary Applications
Corey DeChant, Casey Icenhour, Shane Keniley, Grayson Gall, Alexander Lindsay, Davide Curreli, Steven Shannon
Summary: This paper presents the verification, benchmarking, and validation efforts of the open-source finite element plasma fluid solver Zapdos based on the MOOSE multiphysics framework. The verification process used the method of manufactured solutions and showed good convergence. Benchmarking against the finite element code LSODI resulted in good agreement. Validation against experimental works showed reasonable agreement at higher pressures. The importance of this work is rated as 8 out of 10.
COMPUTER PHYSICS COMMUNICATIONS
(2023)
Article
Nuclear Science & Technology
Mohammed Shutayfi, Anant Raj, Jacob Eapen, Steven Shannon
Summary: Current pool-type Liquid Metal-Cooled Fast Reactors (LMCFRs) immerse reactor components in sodium coolant and use electromagnetic pumps (EMPs) for coolant circulation. This paper investigates the possibility of using large, outside-vessel annular linear induction pumps (ALIPs) in place of in-vessel ALIPs for LMCFRs. The outside-vessel ALIP design provides the same performance requirements and additional advantages compared to the in-vessel pump with minimal reactor vessel modification and a slight drop in efficiency.
ANNALS OF NUCLEAR ENERGY
(2023)