2016 IEEE International Conference on Plasma Science (ICOPS)最新文献

{"title":"Non-conventional diagnostics of energy and momentum transfer at particle-surface interactions","authors":"T. Trottenberg, A. Spethmann, H. Kersten","doi":"10.1109/PLASMA.2016.7533974","DOIUrl":"https://doi.org/10.1109/PLASMA.2016.7533974","url":null,"abstract":"Summary form only given. The forces that low-temperature plasmas exert on limiting walls and electrodes have not received much attention so far. The reason might be the smallness of such forces and the expected difficulties in their measurement. Therefore, only in cases of special plasmas which were designed for the generation of directed momentum (electric space propulsion), measurements of the force exerted by the plasma on a surface have been reported, e.g. Recently, our group demonstrated that the forces related to plasma-wall interactions are experimentally accessible with some effort. This presentation overviews our experimental approaches in the design of force measuring probes* and reports on recent measurements with probes that have been integrated into a plane wall. The observations are discussed in the light of plasma sheath models as well as prospects for an application as novel plasma diagnostic. The energy, on the other hand, that a plasma transfers to solid surfaces, has already been subject of several investigations for a long time and calorimetric probes have increasingly been applied for plasma diagnostics. Calorimetric and force probes, which are alike in some aspects, are discussed from the viewpoint of momenta of velocity distribution functions.","PeriodicalId":424336,"journal":{"name":"2016 IEEE International Conference on Plasma Science (ICOPS)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114388087","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":"Revisiting the relativistic A6 magnetron","authors":"A. Shlapakovski, J. Leopold, A. Sayapin, Y. Krasik","doi":"10.1109/PLASMA.2016.7534380","DOIUrl":"https://doi.org/10.1109/PLASMA.2016.7534380","url":null,"abstract":"We have recently been studying the relativistic A6 magnetron with a single radial output by 3D-PIC simulations. It was found that a delicate electro-dynamic imbalance, resulting in an impedance mismatching between the magnetron and the generator supplying its power, is responsible for microwave pulse-shortening prior to beginning of cathode plasma expansion.1 Also, it was shown that pulse shortening can be eliminated by affecting the relevant impedances through changes in the emitted cathode electron current.","PeriodicalId":424336,"journal":{"name":"2016 IEEE International Conference on Plasma Science (ICOPS)","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123910356","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":"Modeling the chemical kinetics of dual pulsed plasma sources for reduction of NOx emission","authors":"H. Kim, H. Lee","doi":"10.1109/PLASMA.2016.7534127","DOIUrl":"https://doi.org/10.1109/PLASMA.2016.7534127","url":null,"abstract":"Summary form only given. The remediation of NOx emission from diesel exhaust or gas turbines has been widely studied for atmospheric pollution and human health. In order to reduce exhaust gases, non-thermal atmospheric plasmas, Selective Catalytic Reduction(SCR), and SCR with plasma technology have been use. SCR with plasma technology has the highest efficiency to remove NOx emission. However, because of the high maintenance cost and frequent replacement of catalysts, plasma technology not in combination with a catalyst has been interesting. We investigate the efficiency of NOx reduction by dual pulsed atmospheric air plasma sources. NOx concentration is controlled by the variation of high frequency and low frequency of dual pulsed plasma. In Global simulation, a detailed reaction mechanism about NO, NO2, N2O remediation is proposed with single pulse and dual pulses. Main reactions are use d to develop 1-D fluid and hybrid simulation. In these simulations, spatial distribution of radicals and electron densities is investigated. Major pathway of NOx concentration is presented in different spatial position. In this research, simulation results show that dual pulsed plasma can reduce NOx emission more than single pulsed plasma. It can be a new solution for NOx reduction.","PeriodicalId":424336,"journal":{"name":"2016 IEEE International Conference on Plasma Science (ICOPS)","volume":"22 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121281387","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":"MAGIC3D simulations on overmoded W-band coupled-cavity traveling-wave tube","authors":"Yongjun Hong, J. So, Hae-Gun Kim, R. Temkin","doi":"10.1109/PLASMA.2016.7533989","DOIUrl":"https://doi.org/10.1109/PLASMA.2016.7533989","url":null,"abstract":"In this paper MAGIC3D Particle-in-cell (PIC) simulations of overmoded W-band coupled-cavity traveling-wave tube (CCTWT) are shown. The computational analysis of W-band coupled-cavity slow-wave structure was conducted using an electromagnetic CST-MWS, HFSS, and PIC code MAGIC3D. We investigated the large-signal and nonlinear beam dynamics of the W-band CCTWT using MAGIC3D. Simulations predict that the 86-cavity overmoded W-band CCTWT produces 290 W of saturated power with an input power of 0.5 W and a gain of 27.6 dB at 95 GHz when the beam voltage and current are set to 30 kV and 330 mA, respectively, under flat magnetic field of 2.5 kG along total 86 cavities. The saturated bandwidth is calculated to be 600 MHz from 94.6 GHz to 95.2 GHz. The overmoded TWT is a promising approach for high power operation at W-band TWT and higher frequencies TWTs application1.","PeriodicalId":424336,"journal":{"name":"2016 IEEE International Conference on Plasma Science (ICOPS)","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134315159","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":"Development of high step-up converter based on electric double-layer capacitors for DC plasma power supply","authors":"Jong-Hong Hwang, Ji-Eun Baek, K. Ko","doi":"10.1109/PLASMA.2016.7534143","DOIUrl":"https://doi.org/10.1109/PLASMA.2016.7534143","url":null,"abstract":"Summary form only given. A various power supplies for generating the plasma have been studied for decades. DC supply based on electric double-layer capacitor (EDLC) banks was studied and developed in this paper. EDLC has many advantages such as high power density, high speed charging/discharging characteristics1. Although EDLC is suitable for pulsed power applications as prime power, voltage rating of EDLC is so low that it has been rarely used. We proposed the high step-up converter to generate the high voltage DC-pulse from prime power using EDLCs. Supplying the stable voltage and current is an important part in DC plasma process. In previous pulsed power system, intermediate energy storage and pulse forming line are required for compression and shaping of the pulse2. Proposed converter is able to perform the compression and shaping without them. This idea needs two important abilities; one is that the converter should have a high voltage gain. Another is that the converter could cope with rapidly decreasing input voltage. In this paper, we proposed the idea and defined the system using high step-up converter. Also, the converter was verified with simulation. Proposed system and idea will promote the fusion works combining pulsed power and power electronics. Also, the developed power supplies are able to provide proper power to various plasma applications3.","PeriodicalId":424336,"journal":{"name":"2016 IEEE International Conference on Plasma Science (ICOPS)","volume":"41 10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131106217","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":"Microwave plasma-assisted deposition of boron doped single crystal diamond","authors":"T. Grotjohn, A. Bhattacharya, S. Zajac","doi":"10.1109/PLASMA.2016.7534222","DOIUrl":"https://doi.org/10.1109/PLASMA.2016.7534222","url":null,"abstract":"The homoepitaxial growth of diamond on single crystal substrates is done using microwave plasma-assisted chemical vapor deposition with a hydrogen-methane plasma. The doping of the deposited diamond with boron makes it a p-type semiconductor and with phosphorus makes it an n-type semiconductor. The doping of diamond is done to make diamond electronic devices. Diamond is of interest for electronics as it has a wide bandgap (5.4 eV), the highest thermal conductivity of all solid materials at room temperature, a high electric field breakdown strength (10 MV/cm), and high hole and electron carrier mobilities. This presentation will describe the boron doping of diamond by adding diborane into the feedgas of the plasma discharge. For electronic devices controlled doping levels of the boron in the diamond from 1015 cm-3 up to above 1020 cm-3 are desired. The primary control of the doping level is the amount of diborane added to the feedgas. Levels of diborane concentrations in the feedgas as measured by the [B]/[C] ratio in the feedgas range from 0.3 ppm to over 1000 ppm in our study. While the diborane concentration in the feedgas is of primary importance many other factors are also important to the boron concentration in the diamond including residual boron in the deposition system from previous runs, temperature of the substrate, preparation of the substrate, and conditions of the plasma discharge including its power density and pressure. An additional consideration in the doping of diamond is keeping unwanted impurities out of the deposition process. This is especially true of nitrogen impurities which are easily incorporated into the diamond during deposition and which compensates the boron doping, especially at low boron doping concentrations. This presentation will discuss measures taken in the design and operation of a microwave plasma diamond deposition system to control the boron doping and reduce the unwanted impurities.","PeriodicalId":424336,"journal":{"name":"2016 IEEE International Conference on Plasma Science (ICOPS)","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133603821","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":"Numerical investigations of radially converging electron beam generated in cylindrical GESA IV facility","authors":"R. Fetzer, W. An, A. Weisenburger, G. Mueller","doi":"10.1109/PLASMA.2016.7534093","DOIUrl":"https://doi.org/10.1109/PLASMA.2016.7534093","url":null,"abstract":"The cylindrical triode-type electron accelerator GESA IV was developed for treatment of metallic rods, specifically cladding tubes for nuclear reactors. The target (anode) diameter is therefore fixed at about 10 mm by the application, which leads to problems of homogeneity and stability of the radially converging beam. Due to the large difference between cathode diameter (about 150 mm) and anode diameter, a virtual cathode may form between grid and anode, electrons may miss the target and start to circulate around the anode, and the self-induced magnetic field may lead to large distortion of the electron trajectories. In this study, we investigate the influence of various crucial effects on the beam performance by PIC code simulations using the software package MAGIC. In particular, we consider monopolar and bipolar flow (i.e., the influence of ions generated at the target and moving towards the cathode), the effects of scattering at the grid and of backscattering at the target, the angular velocity spread of the electrons at emission, and the influence of the grid potential. The numerical results are compared with experiments performed at the GESA IV facility, where the influence of the target material and of the self-induced magnetic field on the beam performance are investigated.","PeriodicalId":424336,"journal":{"name":"2016 IEEE International Conference on Plasma Science (ICOPS)","volume":"283 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124245602","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":"The self-breakdown characteristics of the magnetic delayed pseudospark switch","authors":"Jiaqi Yan, W. Ding, Yanan Wang, Yongsheng Wang, Y. Gou, K. Qian","doi":"10.1109/PLASMA.2016.7534035","DOIUrl":"https://doi.org/10.1109/PLASMA.2016.7534035","url":null,"abstract":"Summary form only given. Pseudospark switches and magnetic switches have developed respectively for decades. But rare effort has been devoted to the combination of them and further, the coupling performances. This paper deals with the self-breakdown characteristics of a magnetic delayed pseudospark switch (MDPSS), which is a pseudospark switch being in series with a magnetic switch. By incorporating the advantages of pseudospark switches and magnetic switches, MDPSS shows great potential in the application o f repetitive pulsed power system. Furthermore, the commutation loss of pseudospark switches and the size o f magnetic switches are significantly reduced. A repetitive pulsed platform, which can generate voltage pulses with the amplitude of 15 kV at the frequency of 50 Hz, was set up. A MDPSS prototype was elaborately designed, o f which the maximum hold-off voltage is ~30kV. With this platform, the operating and conducting characteristics o f the prototype under repetitive pulses were studied. The results showed that, firstly, the conduction delay of the pseduospark switches is hundreds o f microseconds in the first discharge, and about 1μs in subsequent discharges without triggering under 10kV, 50Hz repetitive voltage pulses. The delay and jitter o f the first discharge is much worse than those of the subsequent discharges. Secondly, magnetic switches with suitable volt-second product have great \"magnetic delayed\" effect which delay the rise of the current flowing through the pseudospark switch, leading to the fact that the hold-off voltage across the pseudospark switch dropped to a pretty low value before the current rose rapidly. This resulted in a great reduction of commutation loss during the switching period o f pseudospark switches. The loss was reduced to 7.5 times lower than before, and could further be reduced in future studies. Meanwhile, magnetic delayed effect was enhanced with the increase o f the volt-second product. Finally, its future applications are discussed. Self-breakdown characteristics o f MDPSS not only are the preliminary researches for the triggered ones, but also have significant applications, like the synchronization o f multistage Marx generators. MDPSS shows great repetitive performances and have substantial potential to become the main switches in pulsed power technology.","PeriodicalId":424336,"journal":{"name":"2016 IEEE International Conference on Plasma Science (ICOPS)","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125760648","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":"Diagnostics of non-equilibrium atmosperic plasma jets for cancer therapy","authors":"M. Keidar","doi":"10.1109/PLASMA.2016.7534180","DOIUrl":"https://doi.org/10.1109/PLASMA.2016.7534180","url":null,"abstract":"Summary form only given. Plasma medicine is a relatively new field that outgrew from research in application of low-temperature (or cold) non-equilibrium atmospheric plasmas in bioengineering. One of the most promising applications of cold atmospheric plasma (CAP) is the cancer therapy. Convincing evidence of CAP selectivity towards the cancel cells has been accumulated. This presentation will review recent research efforts in developing various diagnostics of non-equilibrium atmospheric plasma jets. In particular, we will focus on kHz frequency range discharges. Variety of experimental diagnostic approaches was developed including Rayleigh microwave scattering, Thomson laser scattering, electrostatic streamer scatterers, optical emission spectroscopy, and fast imaging. We will address phenomena related to atmospheric nonequilibrium jets including ionization mechanism, process of ionization front propagation, electrical coupling of the ionization front with the discharge electrodes, distributions of excited and ionized species etc. In general, it was found that there is good electric conductivity of the streamer channel and electrodes potential is transferred to the streamer tip without significant potential. Air content in the helium flow governs streamer propagation along the straight path, its cross-sectional structure, and maximal streamer length. Excitation of the streamer with low frequency high voltage is associated with the streamer initiation at the moment when minimal breakdown conditions are reached.","PeriodicalId":424336,"journal":{"name":"2016 IEEE International Conference on Plasma Science (ICOPS)","volume":"144 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130021266","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":"Dynamics of nanosecond laser produced plasma","authors":"Jian Wu, Xingwen Li, Zefeng Yang, S. Jia, A. Qiu","doi":"10.1109/PLASMA.2016.7534061","DOIUrl":"https://doi.org/10.1109/PLASMA.2016.7534061","url":null,"abstract":"Summary form only given. Laser produced plasmas (LPP) have various applications including laser induced breakdown spectroscopy, superconducting films fabrication, and nanoparticles formation. Although massive efforts have been made, Understanding dynamics of nanosecond laser produced plasma still requires a long-term effort due to the complicated interactions among the laser, the target, the ambient environment, and the plasma. New achievements are obtained due to the improvements of the plasma diagnostics, the developments of numerical codes, and expansions of the application fields.","PeriodicalId":424336,"journal":{"name":"2016 IEEE International Conference on Plasma Science (ICOPS)","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134499911","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}