2022 IEEE International Conference on Plasma Science (ICOPS)最新文献_第4页

Microgravity Dusty Plasmas Exhibit Properties Of Liquid Crystals 微重力尘埃等离子体表现出液晶的特性

2022 IEEE International Conference on Plasma Science (ICOPS) Pub Date : 2022-05-22 DOI: 10.1109/ICOPS45751.2022.9813252

E. Kostadinova, E. Gehr, E. Guay, L. S. Matthews, T. Hyde

{"title":"Microgravity Dusty Plasmas Exhibit Properties Of Liquid Crystals","authors":"E. Kostadinova, E. Gehr, E. Guay, L. S. Matthews, T. Hyde","doi":"10.1109/ICOPS45751.2022.9813252","DOIUrl":"https://doi.org/10.1109/ICOPS45751.2022.9813252","url":null,"abstract":"This study examines structure and stability of filamentary dusty plasmas using data from the Plasmakristall-4 (PK-4) facility on board the International Space Station. Microgravity dusty plasmas have been observed to form extended field-aligned filaments in the DC discharge of the PK-4 experiments, which have been compared to the filamentary state in electrorheological (ER) fluids. Here we show that analysis of the filamentary state of dusty plasma suggests that meaningful comparisons can be made between these microgravity structures and liquid crystals (LCs) with rod-shaped molecules. Specifically, we demonstrate that the coupling between dust particles within filaments is crystal-like, while the coupling across filaments is liquid-like. In addition to a common orientation along a director axis (nematic behavior), the dust filaments also appear to align in large-scale nested structures, or shells (smectic behavior). Finally, the dust filaments are found to arrange in hexagonal patterns in the plane perpendicular to their director axis, suggesting the possibility of a smectic-B or smectic-C state. Based on these observations, we will argue that microgravity filamentary dusty plasmas can be used to study universality of phase transitions and pattern formation in liquid crystals.","PeriodicalId":175964,"journal":{"name":"2022 IEEE International Conference on Plasma Science (ICOPS)","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127580770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Modeling Burn Physics in a Magnetized ICF Plasma 磁化ICF等离子体中的燃烧物理建模

2022 IEEE International Conference on Plasma Science (ICOPS) Pub Date : 2022-05-22 DOI: 10.1109/ICOPS45751.2022.9813321

S. O'Neill, B. Appelbe, J. Chittenden

{"title":"Modeling Burn Physics in a Magnetized ICF Plasma","authors":"S. O'Neill, B. Appelbe, J. Chittenden","doi":"10.1109/ICOPS45751.2022.9813321","DOIUrl":"https://doi.org/10.1109/ICOPS45751.2022.9813321","url":null,"abstract":"The pre-magnetization of inertial confinement fusion capsules is a promising avenue for reaching hotspot ignition, as the magnetic field reduces electron thermal conduction losses during hotspot formation. However, in order to reach high yields, efficient burn-up of the cold fuel is vital. Suppression of heat flows out of the hotspot due to magnetization can restrict the propagation of burn and has been observed to reduce yields in previous studies [1] . This work investigates the potential suppression of burn in a magnetized plasma utilizing the radiation-MHD code ‘Chimera’ in a planar geometry.. This code includes extended-MHD effects, such as the Nernst term, and a Monte-Carlo model for magnetized alpha particle transport and heating. We observe 3 distinct regimes of magnetized burn in 1D as initial magnetization is increased: thermal conduction driven; alpha driven; and suppressed burn. Field transport due to extended-MHD is also observed to be important, enhancing magnetization near the burn front. In higher dimensions, burn front instabilities have the potential to degrade burn even more severely. Magneto-thermal type instabilities (previously observed in laser-heated plasmas [2] ) are of particular interest in this problem.","PeriodicalId":175964,"journal":{"name":"2022 IEEE International Conference on Plasma Science (ICOPS)","volume":"90 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130967577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Particle-in-Cell Simulations of Nonlinear Plasma Sheath Effects on Impedance of VLF Antenna Operating in the Magnetosphere 非线性等离子体鞘层对VLF天线磁层阻抗影响的粒子胞内模拟

2022 IEEE International Conference on Plasma Science (ICOPS) Pub Date : 2022-05-22 DOI: 10.1109/ICOPS45751.2022.9813221

K. Shipman, P. Colestock, D. Svyatsky, M. Gilmore, Q. Marksteiner, G. Delzanno

{"title":"Particle-in-Cell Simulations of Nonlinear Plasma Sheath Effects on Impedance of VLF Antenna Operating in the Magnetosphere","authors":"K. Shipman, P. Colestock, D. Svyatsky, M. Gilmore, Q. Marksteiner, G. Delzanno","doi":"10.1109/ICOPS45751.2022.9813221","DOIUrl":"https://doi.org/10.1109/ICOPS45751.2022.9813221","url":null,"abstract":"A powerful coronal mass ejection or a high-altitude nuclear explosion (HANE) can produce an artificial radiation belt containing high-energy electrons (~1MeV) in the earth’s upper atmosphere that would populate its magnetosphere. Some of these high-energy electrons become trapped along the Earth’s magnetic field lines and would severely damage or destroy nearly all lower-earth orbit (LEO) satellites in just a few days. Over the years, it has been of much interest to devise a scheme that remediates these MeV electrons from the magnetosphere and reduces the amount of damage caused by them. A proposed technique is to use a space-borne high-voltage dipole antenna to inject very low frequency (VLF) whistler waves (3-30kHz) along the earth’s magnetic field lines to precipitate the electrons through pitch angle scattering. Because the magnetosphere is composed of plasma, a charged antenna will form a nonlinear plasma sheath around its surface. This sheath changes the input impedance of the antenna, reducing efficiency. This research uses a three-dimensional electrostatic curvilinear particle-in-cell (CPIC) code to simulate the antenna-sheath interaction to calculate the impedance induced by the sheath. We compare the numerical results to an existing analytical developed by Balmain et al. and Song et al. [1] [2] .","PeriodicalId":175964,"journal":{"name":"2022 IEEE International Conference on Plasma Science (ICOPS)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133601399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Production of Methyl Radicals in Atmospheric Pressure Microreactors for Up-Conversion to High Values Hydrocarbons 常压微反应器上转化高值烃甲基自由基的产生

2022 IEEE International Conference on Plasma Science (ICOPS) Pub Date : 2022-05-22 DOI: 10.1109/ICOPS45751.2022.9813290

S. Kerketta, K. Wolf, R. Hartman, M. Kushner

{"title":"Production of Methyl Radicals in Atmospheric Pressure Microreactors for Up-Conversion to High Values Hydrocarbons","authors":"S. Kerketta, K. Wolf, R. Hartman, M. Kushner","doi":"10.1109/ICOPS45751.2022.9813290","DOIUrl":"https://doi.org/10.1109/ICOPS45751.2022.9813290","url":null,"abstract":"The on-site up-conversion of methane (CH 4 ) to higher value hydrocarbons is being investigated as a means to minimize the emission of global warming methane during oil production. One proposed method is production of methyl (CH 3 ) radials by a low temperature plasma, followed by reaction with organic metallic complexes in solution. Production of CH 3 radicals using dielectric barrier discharge (DBD) plasma microreactors is being computationally and experimentally investigated. A typical microreactor consists of a 500 μm gap etched on a Si substrate and covered with borosilicate glass as the dielectric. Nanosecond high voltage pulses of up to 10 kV operating at frequencies of 1-10 kHz were used to generate atmospheric pressure plasma in the feed gas consisting of mixtures of Ar and CH 4 . nonPDPSIM , a 2D plasma hydrodynamics model was used to simulate the plasma generation and subsequent plasma chemistry initiated by electron impact dissociation of CH 4 . The spatial and temporal evolution of CH 3 radicals will be discussed as a function of reactor geometry, gas mixture, and solvent location (e.g., along walls or in droplets). Although methyl radicals can be efficiently produced, there is also rapid formation of ethylene (C 2 H 6 ) in the gas phase. The location of CH 3 formation with respect to the solvent is therefore important in maximizing the solvation of the CH 3 radicals for further up-conversion.","PeriodicalId":175964,"journal":{"name":"2022 IEEE International Conference on Plasma Science (ICOPS)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132742234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Absence of Space-Charge-Limited Current from Abnormal Field Emission in Collisional Diode 碰撞二极管异常场发射中空间电荷限制电流的缺失

2022 IEEE International Conference on Plasma Science (ICOPS) Pub Date : 2022-05-22 DOI: 10.1109/ICOPS45751.2022.9813168

L. Ang, C. Chua, Y. Ang

{"title":"Absence of Space-Charge-Limited Current from Abnormal Field Emission in Collisional Diode","authors":"L. Ang, C. Chua, Y. Ang","doi":"10.1109/ICOPS45751.2022.9813168","DOIUrl":"https://doi.org/10.1109/ICOPS45751.2022.9813168","url":null,"abstract":"For field emission in a vacuum or solid diode, its current density is expected to be governed by the Child-Langmuir [1] or Mott-Gurney laws [2] law at sufficiently high voltage. Recently, we reported that for field emission not obeying the classical Fowler-Nordheim (FN) law [3] , the two-stage transition from source-limited field emission (FE) to space-charge-limited current (SCLC) is no longer valid [4] . Using a generalized FN scaling of ln(J/F k ) □ 1/F, where J is the current density and F is the applied field, we study the effects of different k to the current density-voltage (J-V) transition characteristic. For a vacuum diode, if the value of k is smaller than k crit =1.5, we will have pure FE with absolute absence of SCLC or 3-stage FE-to-SCLC-to-FE, depending on the size of the diode D. We extend the model to a solid diode (collisional transport), and the corresponding critical value becomes k crit =2. The transition behavior is more complicated, which depends not only on D, but also the electron mobility μ in the solid. Our findings provide a theoretical foundation for modelling unconventional field emission injection in both ballistic and collisional regimes, which is significant for various applications [5] in vacuum electronics, beam physics, gas-based diode, plasma, and dielectric.","PeriodicalId":175964,"journal":{"name":"2022 IEEE International Conference on Plasma Science (ICOPS)","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128881435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Power Calculations for Overmoded High Power Millimeter-Wave Devices 超模高功率毫米波器件的功率计算

2022 IEEE International Conference on Plasma Science (ICOPS) Pub Date : 2022-05-22 DOI: 10.1109/icops45751.2022.9812957

A. Elfrgani, J. Vijayamohanan, J. Giese, A. Kuskov, N. Burt, E. Schamiloglu

引用次数: 0

Modeling a VLF Antenna In Space Plasma Using Nascap-2k 利用Nascap-2k对空间等离子体中VLF天线进行建模

2022 IEEE International Conference on Plasma Science (ICOPS) Pub Date : 2022-05-22 DOI: 10.1109/ICOPS45751.2022.9813024

D. Cooke, M. Mandell, V. Davis, M. Starks, D. Ferguson

引用次数: 0

Flat Wave-Cutoff Sensor for Real-Time Industrial Plasma Process Monitoring 用于工业等离子体过程实时监测的平面波截止传感器

2022 IEEE International Conference on Plasma Science (ICOPS) Pub Date : 2022-05-22 DOI: 10.1109/ICOPS45751.2022.9813199

H.-C. Lee, J. Kim

引用次数: 0

Particle-In-Cell Simulations of Two Cylindrical Reflex Triodes in Parallel 两个平行圆柱形反射三极管的细胞内粒子模拟

2022 IEEE International Conference on Plasma Science (ICOPS) Pub Date : 2022-05-22 DOI: 10.1109/icops45751.2022.9813171

I. Rittersdorf, B. Weber, S. Swanekamp, P. Adamson

{"title":"Particle-In-Cell Simulations of Two Cylindrical Reflex Triodes in Parallel","authors":"I. Rittersdorf, B. Weber, S. Swanekamp, P. Adamson","doi":"10.1109/icops45751.2022.9813171","DOIUrl":"https://doi.org/10.1109/icops45751.2022.9813171","url":null,"abstract":"Pulsed power diodes that generate bremsstrahlung x-rays are of interest as sources for radiation-matter interaction studies. The cylindrical reflex triode (CRT) is one such diode that is notable for its ability to produce low-endpoint x-ray spectra and its design is favorable to combine multiple CRTs to increase x-ray output, in either series or parallel configurations [1] . CRTs in various configurations are fielded on NRL’s Gamble II generator. This work marks the first particle-in-cell (PIC) simulations of a CRT and will focus on two CRTs in parallel in support of recent Gamble II experiments. The PIC simulations will be used to predict current measurements for the inner and outer triodes as well as report direct voltage measurements near the anode-cathode gap. Radiation production calculations based on the PIC simulation particle outputs will be made to make predictions of the time dependent x-ray production, near field radial dose distribution, and x-ray source distribution. These calculations will be validated against Gamble II experiments. Successful confidence in predictive capability with the model will allow for the development of synthetic x-ray spectra diagnostics.","PeriodicalId":175964,"journal":{"name":"2022 IEEE International Conference on Plasma Science (ICOPS)","volume":"180 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114855824","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Field Emission Model with Diminishing Thickness from Bulk to 2D materials 从块状到二维材料厚度递减的场发射模型

2022 IEEE International Conference on Plasma Science (ICOPS) Pub Date : 2022-05-22 DOI: 10.1109/ICOPS45751.2022.9813353

W. J. Chan, Y. Ang, L. Ang

{"title":"Field Emission Model with Diminishing Thickness from Bulk to 2D materials","authors":"W. J. Chan, Y. Ang, L. Ang","doi":"10.1109/ICOPS45751.2022.9813353","DOIUrl":"https://doi.org/10.1109/ICOPS45751.2022.9813353","url":null,"abstract":"Two-dimensional (2D) materials-based field emitters, such as graphene and 2D topological materials, have attracted enormous attention due to their excellent field emission properties and performance. However, the modelling of the out-of-plane electron emission still poses a serious physics challenge. The lack of crystal periodicity and the confinement of electrons within the 2D material atomic plane have challenged the conventional physical picture of field emission from 3D metals developed in the past century. To resolve this problem for field emission, a quasi-2D model two-barrier model has been developed to study the behaviour of field emission when the material geometry is continuously shrunken from 3D bulk emitters to 2D emitters using a phenomenological quantum well method. The predicted findings agree well with the respective limits of large and thin materials, corresponding to the field emission by 3D (or bulk) and 2D materials, respectively. The model provides a comprehensive understanding of the field emission for finite layers of 2D materials in addition to the well-studied 2D thermionic electron emission. These recent works have suggested that the classical scaling laws developed decades ago for field and thermal-field emission may not be valid in the 2D flatland.","PeriodicalId":175964,"journal":{"name":"2022 IEEE International Conference on Plasma Science (ICOPS)","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114705584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0