2020 IEEE International Conference on Plasma Science (ICOPS)最新文献

{"title":"Application of Repetitive Nanosecond Pulse Generator Based on Avalanche Transistors in Plasma Jet","authors":"S. Shen, Jiaqi Yan, Guoxiang Sun, W. Ding","doi":"10.1109/ICOPS37625.2020.9717853","DOIUrl":"https://doi.org/10.1109/ICOPS37625.2020.9717853","url":null,"abstract":"Atmospheric pressure plasma jet (APPJ) is a gas discharge phenomenon in which the active particles generated in the discharge space are transmitted to the atmospheric environment under the combined action of electric field and flow field. Its flexibility and maneuverability make it more suitable for dealing with uneven surfaces and complex 3D materials, so that it has been widely used in the fields of material modification, surface sterilization and film deposition[1]. The generating conditions and characteristics of APPJ are closely related to the driving source. Compared with the discharge under conventional AC and DC driving sources, discharge under nanosecond pulse can provide higher power density and higher E / N due to its ultra-fast rise time. It promotes the reactions that cannot be achieved under conventional conditions and is more favorable for the generation of APPJ [2].","PeriodicalId":122132,"journal":{"name":"2020 IEEE International Conference on Plasma Science (ICOPS)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127662839","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}

{"title":"Introduction to Space Environment Experiment Research Facility (SPERF)","authors":"X. Wang","doi":"10.1109/ICOPS37625.2020.9717880","DOIUrl":"https://doi.org/10.1109/ICOPS37625.2020.9717880","url":null,"abstract":"Space Physics Environment Research Facility (SPERF) is a part of the state major fundamental facility for science & technology, Space Environment Simulation Research Infrastructure (SESRI), which has been designed and under construction in Harbin, China. The facility will be run by Harbin Institute of Technology. There are 3 main components of SPERF: Asymmetric Reconnection Experiment (AREX)[1], Dipole Research Experiment (DREX)[2], [3], and Tail Research Experiment (TREX). AREX is for lab simulation of asymmetric reconnection at the dayside magnetopause of the magnetosphere. DREX is for lab simulation of crucial processes in dipole field of radiation belts. And TERX is for lab simulation of magneto tail physics processes.","PeriodicalId":122132,"journal":{"name":"2020 IEEE International Conference on Plasma Science (ICOPS)","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114570518","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}

{"title":"Studies on Hydrogen Plasma in an ECR Based Large Volume Chamber","authors":"Shweta Sharma, D. Sahu, R. Narayanan, S. Kar, R. D. Tarey, A. Ganguli, M. Bandyopadhyay, A. Chakraborty, M.J. Singh","doi":"10.1109/ICOPS37625.2020.9717871","DOIUrl":"https://doi.org/10.1109/ICOPS37625.2020.9717871","url":null,"abstract":"In the present work, hydrogen plasma was investigated in a large volume plasma chamber (dia: 1.0 m and height: 1.0 m). Plasma was produced in an indigenously made compact size ECR plasma source1, 2, (dia: 0.09 m, length: 0.11 m) located coaxially within an NdFeB ring magnet assembly, placed at the center of the top dome of the plasma chamber. The magnetic field inside the source generates the ECR zone to permit absorption of the incoming microwave at 2.45 GHz for plasma heating, and extends as a diverging field into the large chamber. Plasma from the source flows along magnetic field to form a beam–like column near the source. Langmuir probe measurements along the chamber axis ($z$) at pressures 1–3 mTorr and input power 400 W show that the plasma density ($n_{e}$) decays rapidly up to $z=20 text{cm}$ from the source mouth ($mathrm{z}=0$) followed by a slow decay thereafter towards the bottom of the chamber. The initial decay profile tracks the axial magnetic field profile closely confirming the $n/B$ scaling obeyed by hydrogen plasma as observed earlier in a smaller vessel3. Radial measurements taken at different $z$ planes show good radial uniformity away from the source. At $z=70 text{cm}, n_{e}approx 3.5-4.0times 10^{10} text{cm}^{-3}$ and $T_{e}approx 1-2 text{eV}$ over 40 cm radius at ≈ 3 mTorr pressure and 400 W power. Studies showed increase in $n_{e}$ with the pressure, although increasing the microwave power did not alter the density or temperature significantly. The good radial uniformity and the low $T_{e}$ could be useful for extraction of H− beams. Results from these experiments will be presented in this manuscript.","PeriodicalId":122132,"journal":{"name":"2020 IEEE International Conference on Plasma Science (ICOPS)","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121860101","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}

{"title":"PReparation of ZnO Nanowire Field Emitter Arrays and Their Device Applications","authors":"Jun Chen","doi":"10.1109/ICOPS37625.2020.9717952","DOIUrl":"https://doi.org/10.1109/ICOPS37625.2020.9717952","url":null,"abstract":"Large area nanowire field emitter arrays have potential applications in flat panel light source, X-ray source, and photodetector etc. In this invited talk, our recent progresses in the research of ZnO nanowire field emitter arrays and their applications in vacuum microelectronic devices will be presented. Large area ZnO nanowire field emitter arrays up to 8 inch diagonal size with high emission current were prepared. Gate-structured ZnO nanowire field emitter arrays with addressing and focusing capabilities were fabricated. Applications of nanowire field emitter in flat panel x-ray source and imaging detector were explored. Prototype of flat panel X-ray source using ZnO nanowire field emitters was fabricated and high resolution imaging capability was demonstrated. The feasibility of a large area high-sensitive detector using ZnO nanowire field emitters was also verified.","PeriodicalId":122132,"journal":{"name":"2020 IEEE International Conference on Plasma Science (ICOPS)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121884379","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}

{"title":"Machine Learning Controlled Self-Adaptive Plasma Medicine","authors":"Li Lin, M. Keidar","doi":"10.1109/icops37625.2020.9717737","DOIUrl":"https://doi.org/10.1109/icops37625.2020.9717737","url":null,"abstract":"Cold atmospheric plasma (CAP) medicine is a novel technology of drug delivery that potentially has diverse applications including cancer treatment, tissue generation, sterilization, and blood coagulation1. Previously, we proposed an idea of self-adaptive plasma which can automatically optimize the plasma parameters such as reactive oxygen and nitrogen species (RONS) to immune the dynamic environmental disturbance and target status2,3. As the next step of self-adaptive plasma, a machine-learning based plasma control system is required.","PeriodicalId":122132,"journal":{"name":"2020 IEEE International Conference on Plasma Science (ICOPS)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122117582","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}

{"title":"Signal Propagation in Myelin Sheath as Dielectric Waveguide in the Mid-Infrared to Terahertz Spectral Range","authors":"Chao Chang, Z. Qiao, K. Wu, Y. Huang","doi":"10.1109/ICOPS37625.2020.9717635","DOIUrl":"https://doi.org/10.1109/ICOPS37625.2020.9717635","url":null,"abstract":"The myelin sheath enables dramatic speed enhancement for signal propagation in nerves. In this work, myelinated nerve structure is experimentally and theoretically studied using synchrotron-radiation-based Fourier-transform infrared microspectroscopy. We experimentally demonstrated the high contrast of mid-infrared reflectivity/refractivity between the myelin sheath and other structures in nervous tissue [1]. It is found that, with a certain mid-infrared to terahertz spectral range, the myelin sheath possesses $mathrm{a}approx 2$ - fold higher refraction index compared to the outer medium or the inner axon, suggesting that myelin can serve as an infrared dielectric waveguide. By calculating the correlation between the material characteristics of myelin and the radical energy distribution in myelinated nerves, it is demonstrated that the sheath, with a normal thickness $(approx 2mu mathrm{m})$ and dielectric constant in nature, can confine the infrared field energy within the sheath and enable the propagation of an infrared signal at the millimeter scale without dramatic energy loss. The infrared and THz energy concentration in myelin mainly depends on the myelin thickness, the difference of dielectric constant between the myelin and axon fluid, rather than the absolute values of the inner radius and inner dielectric constant of axon. The energy of signal propagation is supplied and amplified when crossing the nodes of Ranvier via periodic relay. These findings provide the first model for explaining the mechanism of infrared and terahertz neurotransmission through myelinated nerves, which may promote the development of biological-tissue label-free detection, biomaterial-based sensors, neural information, and noninvasive brain-machine interfaces.","PeriodicalId":122132,"journal":{"name":"2020 IEEE International Conference on Plasma Science (ICOPS)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123033372","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}

{"title":"Effect of Plasma Input Power and Feeding Speed on the Surface Temperatures of Stainless Steel 316L During Plasma Assisted Milling","authors":"Min-Gyu Choi, S. Chung, In-Mok Yang, J. Nam, Hyo-Jeong Kim, Jeongmo Yoon, J. Seo","doi":"10.1109/ICOPS37625.2020.9717652","DOIUrl":"https://doi.org/10.1109/ICOPS37625.2020.9717652","url":null,"abstract":"By heating up the workpiece metal and softening it thermally in front of conventional cutting tool, plasma assisted milling is expected to improve the cutting performance and tool-life without using cutting oil and coolant [1]. Accordingly, it is essential to understand the effects of the operation condition of milling machine combined with a plasma torch on the surface temperatures of the selected workpiece before applying this technology to the specific materials. For this purpose, the surface temperatures of stainless steel 316L were measured using an IR (Infra-Red) thermometer for three different cutting speed (150,200, 250 mm/min) by varying plasma input powers. In addition, the measured results were compared with the analytic solution, which was derived for moving surface heat source with square shape [2].","PeriodicalId":122132,"journal":{"name":"2020 IEEE International Conference on Plasma Science (ICOPS)","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126673234","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}

{"title":"Mass Separaton by Oscillating Electromagnetic Fields","authors":"A. Fruchtman, G. Makrinich","doi":"10.1109/ICOPS37625.2020.9717861","DOIUrl":"https://doi.org/10.1109/ICOPS37625.2020.9717861","url":null,"abstract":"It is shown that if the phase difference between oscillating electric and magnetic field is judiciously chosen, particles are accelerated along a line that is perpendicular to those fields. Moreover, the direction of acceleration depends on the particle mass, so that species of (even small) mass difference, are accelerated in opposite directions. Two configurations are addressed. One configuration is of a linearly-polarized electric and magnetic fields. In a second configuration, a steady axial magnetic field is added to circularly-polarized oscillating fields. For an appropriate phase difference, charged particles, the cyclotron frequencies of which lie on the two opposite sides of the cyclotron resonance, are accelerated in opposite directions. Ion collisions with neutrals cause the ion acceleration to result in a drift velocity of the ions. Surprisingly, the collisions do not impede the mass separation. The direction of the drift also depends on mass. Mass separation, separation of particles of different mass, is a crucial process in a variety of societal applications [1]–[3]. This phase-induced mass-selective acceleration presented here can be the basis for a novel mass separation scheme.","PeriodicalId":122132,"journal":{"name":"2020 IEEE International Conference on Plasma Science (ICOPS)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129534040","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}

{"title":"Optimization of a Mega-Ampere DPF with Monolithic Beryllium Electrodes for High Neutron Yield","authors":"E. Lerner, S. Hassan, I. Karamitsos, Rudolph Fritsch, J. Varela","doi":"10.1109/ICOPS37625.2020.9717885","DOIUrl":"https://doi.org/10.1109/ICOPS37625.2020.9717885","url":null,"abstract":"The dense plasma focus FF-2B machine with 1.2 MA peak current is designed as a low-impurity fusion device for a high neutron yield. Using for the first time monolithic beryllium electrodes, FF-2B has achieved a forty-fold reduction of impurities by mass with a dramatic reduction in electrode erosion as compared with previous copper1 and tungsten2 electrodes. We observed evenly-spaced filaments initially in the sheath, but the leading portion of the current sheath becomes disordered during run-down, limiting compression and fusion yield. Oscillations in the initial 200 ns of the current pulse are a possible cause of this disordering and we discuss possible mitigations. The impedance of the FF-1 and FF-2B devices at the pinch for both the 10cm and 14cm electrodes was correlated with the fusion yield. To obtain improved neutron yield with beryllium electrodes, we are reducing the inductance of the machine with a doubling of the number of switches.","PeriodicalId":122132,"journal":{"name":"2020 IEEE International Conference on Plasma Science (ICOPS)","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130106362","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}

{"title":"Plasma-Assisted Combustion Above Atmospheric Pressure: Challenges and Opportunities","authors":"D. Lacoste","doi":"10.1109/ICOPS37625.2020.9717741","DOIUrl":"https://doi.org/10.1109/ICOPS37625.2020.9717741","url":null,"abstract":"Over the last decade, combustion enhancement by non-equilibrium plasma discharges has been increasingly investigated. The aim of these studies is to evaluate if electrical discharges can enhance flames by applying an electrical power negligible compared to the thermal power released by the combustion mechanisms. In this context, non-thermal plasmas were successfully used to enhance the flammability limits, increase the burning velocity, improve ignition, facilitate the transition to detonation and control thermo-acoustic instabilities, in various configurations1. However, the vast majority of these studies were carried out at atmospheric pressure, while in real combustion systems, the pressure is usually in the range from 5 to 40 bar. An increase in pressure above atmospheric can impact both the combustion and the discharge processes. The effects of pressure on combustion phenomena are relatively well known, except for the electrical properties of flames. Indeed, while at atmospheric pressure, the concentration of electrons in hydrocarbon flames is known to be about 1010 cm−3, there is no available data at higher pressure. Similarly, the effect of non-equilibrium discharges on combustion properties at pressures above atmospheric are not well documented. In this study, the effect of non-thermal plasmas produced by nanosecond repetitively pulsed (NRP) discharges on the flammability limit of methane-air flames at pressures up to 8 bar is investigated. The NRP discharges are characterized by current and voltage measurements, while the flame stability is assessed by direct visualization performed with a DSLR camera. The results show that NRP discharges can improve the stability of premixed swirl flames at all pressures investigated, even if the ratio of electrical discharge power to flame thermal power is kept as low as 0.7%. It is also observed that the required peak voltage does not increase linearly with increasing the pressure. Based on physical explanations for these results, the challenges and opportunities of plasma-assisted combustion above atmospheric pressure are discussed.","PeriodicalId":122132,"journal":{"name":"2020 IEEE International Conference on Plasma Science (ICOPS)","volume":"510 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127035601","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}