2013 Abstracts IEEE International Conference on Plasma Science (ICOPS)最新文献

{"title":"An overview of research on the “magnetic saw effect”","authors":"F. Stefani, A. Sitzman, T. Watt","doi":"10.1109/PLASMA.2013.6633351","DOIUrl":"https://doi.org/10.1109/PLASMA.2013.6633351","url":null,"abstract":"Summary form only given. The term “magnetic saw effect” was introduced in 1957 by Firth et. al. in [1] to describe an instability observed in high-field pulsed magnets. The instability produces fine, saw-like cuts in solid conductors, often followed by larger openings, which have since been termed “blow holes.” The magnetic saw effect is also been observed in high-current pulsed buswork and more recently in railguns. As instabilities go, magnetic sawing has not been the subject of much research, in part because for most applications it is possible to engineer ones way out of the problem by using larger conductors. It is only within the last 10 years that researchers have sought to better understand the causes of magnetic sawing and the conditions for which magnetic sawing occurs. This paper surveys the literature on magnetic sawing and discusses some of the outstanding research questions, such as the relative importance of melting versus fracture as a driver for magnetic sawing.","PeriodicalId":6313,"journal":{"name":"2013 Abstracts IEEE International Conference on Plasma Science (ICOPS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83605158","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":"Single shot measurements of the E-field vector with pigtailed optical probes","authors":"L. Duvillaret, P. Jarrige, F. Lecoche, G. Gaborit","doi":"10.1109/PLASMA.2013.6635069","DOIUrl":"https://doi.org/10.1109/PLASMA.2013.6635069","url":null,"abstract":"Summary form only given. Over the variety of available sensors dedicated to electric (E)-field characterization, the use of antennas constitutes the most widespread technique. While such probes are convenient and provide a good sensitivity, they remain invasive and bandwidth limited. At the opposite, fibered electro-optic transducers1 are fully dielectric, millimeter sized and allow to perform measurements of the E-field vector from DC to several gigahertz and even up to terahertz frequencies using equivalent-time sampling. Furthermore, recent developments lead to a simultaneous characterization of 2 transverse E-field vector components with a single EO probe2. Based on polarization state modulation, the EO transducer is linked to a remote (up to 30 meters) optoelectronic set-up including a ultra low noise laser feeding the probe and a real time optical set-up to manage the modulation treatment. The automated and servo controlled measurement bench is temperature dependent free. The available measurement dynamics exceeds 100 dB, ranging from less than 1 V. m-1. Hz-1/2 up to the breakdown electric field in air.An exhaustive comparison between BO sensors and other technologies will be firstly given during the conference. This analysis will be based on intrinsic sensor properties, such as sensitivity, frequency bandwidth, vectorial selectivity, spatial resolution and induced perturbation on the field to be measured. After recalling the principles of the BO effect, the optical arrangement of the optical probes will be described. The characterization of the BO system will be presented together with experimental results illustrating the potentialities of BO sensors. Among these examples, measurements of pulsed B-field in air (pulsed power), water (specific absorption rate evaluation in pulsed regime) or in plasma (real time evolution of the electrical discharge associated B-field) will be shown.","PeriodicalId":6313,"journal":{"name":"2013 Abstracts IEEE International Conference on Plasma Science (ICOPS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76284195","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":"Extreme ultraviolet spectroscopy of CU cylindrical wire arrays on zebra at UNR","authors":"E. Petkov, M. Weller, A. Safronova, V. Kantsyrev, A. Esaulov, I. Shrestha, G. Osborne, A. Stafford, V. V. Shlyapsteva, S. Keim, C. Coverdale","doi":"10.1109/PLASMA.2013.6633224","DOIUrl":"https://doi.org/10.1109/PLASMA.2013.6633224","url":null,"abstract":"Extreme ultraviolet (EUV) radiation from z-pinch plasma sources has been shown to play a substantial role in the evolution of z-pinches, contributing significant amounts of radiation in the wire ablation, stagnation, and plasma expansion phases. Recent studies of Cu z-pinch plasmas from cylindrical wire arrays have also shown that high temperatures (up to 450 eV) exist in precursor plasmas, which have applications to inertial confinement fusion. The final expansion phase has shown that substantial EUV radiation continues even after the main x-ray bursts. In this work, EUV data were analyzed with the goal of understanding how the bulk cooler plasma might represent the main contribution to the total radiative output from z-pinch plasmas. In particular, a comparison and analysis of EUV data generated by two plasma sources is shown: the first set of experiments used Cu cylindrical wire arrays on the 1.0 MA Zebra generator at UNR. In addition to EUV data, x-ray data is also analyzed which shows dominant emission of Cu XX ions. The second set used Cu flat targets and was performed at the compact laser-plasma x-ray/EUV facility “Sparky” at UNR, which is used as a unique line calibration source. Moreover, spectral data generated by Sparky generally show more and better resolved lines. Cu L-shell lines in the range of 120-160 Å, specifically CuX to CuXIII ions, are identified. To help with the identification of lines, a non-local thermodynamic equilibrium (non-LTE) kinetic model was utilized and was also used to determine plasma parameters, such as electron temperature and density. Future studies will focus on attaining time-gated EUV spectra in order to better understand its role in the evolution of z-pinch plasmas.","PeriodicalId":6313,"journal":{"name":"2013 Abstracts IEEE International Conference on Plasma Science (ICOPS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73619250","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":"Performance of electrode materials during food processing by pulsed electric fields","authors":"A. Gad, S. Jayaram, M. Pritzker","doi":"10.1109/PLASMA.2013.6635206","DOIUrl":"https://doi.org/10.1109/PLASMA.2013.6635206","url":null,"abstract":"Food processing by pulsed electric fields (PEFs) is a promising non-thermal method for increasing the shelf-life of liquid food products such as milk, juices and beer. Maintaining both the fresh-like taste and the original nutritional value makes PEF processing advantageous over conventional thermal pasteurization1. However, physical contact between the liquid food and the metallic electrodes during the PEF process is unavoidable and causes some metallic ions to be released from the electrodes into the processed food. The released metallic ions represent a challenging problem for this technology because they may affect the taste of the processed food and/or they reduce the life-time of the electrodes.This study is to evaluate the performance of various metals used as the electrodes by comparing the rates of release of metallic ions from chromium, nickel, silver and titanium as well as conventional stainless steel during PEF processing. The concentration of metallic ions in PEF-processed food products are measured using inductively coupled plasma - atomic emission spectrometry (ICP-AES). The first objective of the work is to rank the materials by taking into account both the price and the life-time of each material. This ranking is carried out for a variety of food products having different values of pH and electrical conductivity. Both the rate and price of replacing the electrodes should be considered when assessing the economic feasibility of the PEF process. By investigating the physical and chemical properties of the electrode materials used, the second objective of the work aims to understand more about the mechanism by which the metallic ions are released. Under the extreme conditions of voltage and current applied during typical PEF processing, the classical electrochemical theories may not be sufficient. Understanding more about the mechanism may provide a new basis for better selection of electrode materials.","PeriodicalId":6313,"journal":{"name":"2013 Abstracts IEEE International Conference on Plasma Science (ICOPS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79511030","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":"Weighting schemes for charges and fields to control self-force in unstructured finite element Particle-in-Cell codes","authors":"M. Bettencourt","doi":"10.1109/PLASMA.2013.6633179","DOIUrl":"https://doi.org/10.1109/PLASMA.2013.6633179","url":null,"abstract":"Summary form only given. Particle-in-Cell (PIC) is a powerful technique for simulating physical processes where discrete objects exert forces on each other. In the context of this talk we are examining electrostatic plasmas where the particles represent electrons or ions which are free to move around the system and the electric fields are defined on the mesh. While this talk focuses on electrostatics, the techniques discussed are generalizable to other domains. In traditional structured codes symmetry between the weighting operators which map the particles charge to the mesh and the electric field from the mesh back to the particle results in no self-force. In the unstructured finite element world the traditional approaches result in a self-force which causes a particle to push itself and to violate Newton's laws of motion. This talk focuses on a novel approach in controlling the selfforce of particles in PIC codes. This approach chooses a weighting scheme which closely reproduces the exact potential at grid nodes both near a charged particle and for the long range effects. This potential can then be differenced to compute an electric field at particle locations allowing for a exact cancellation up to the tolerance which the exact solution is reproduced at grid locations. This algorithm can be combined with a particle-particle--particle-mesh (P3M) approach to cancel all local effects and compute the N2 terms directly for a local patch resulting in reduced self-force and superior spatial resolution. This talk will present the details of this algorithm, lower self-force on a single particle, better Coulomb collisions for a few particles, and accurate results for highly under-refined meshes while maintaining the geometric flexibility of unstructured grids.","PeriodicalId":6313,"journal":{"name":"2013 Abstracts IEEE International Conference on Plasma Science (ICOPS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85437651","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":"PPPS-2013: Analysis on circuit-elements-composed-simulator of vircator for electromagnetic pulse emission","authors":"Sung-Gyen Lee, Kun-A Lee, J. Rhee, K. Ko","doi":"10.1109/PPC.2013.6627670","DOIUrl":"https://doi.org/10.1109/PPC.2013.6627670","url":null,"abstract":"Vircator (Virtual Cathode Oscillator), which is one of the microwave sources, has been stuided widely for more than 20 years since it has such advantages as simple structure and high power radiation1. As electromagnetic pulse (EMP) emitted by vircator has been developing, the studies about hazard of the EMP on target have been also increasing2. In these applications it is difficult to build the whole system for EMP protection, because it is costly, dangerous and complex. For this reason, the vircator simulator to be composed circuit elements (R, L, C and etc.) is strongly needed. Numerically, vircator can be analyzed by PIC (Particle In Cell). However it takes too many times in computation. Therefore, the purpose of this paper is to build a vircator simulator via circuit elements, which could have its equivalent behavior with lower computation. In this paper, passive elements and switch are used to model for space-charge limitation, absorptions, oscillation and etc. The number of oscillation between the anode and the virtual cathode is limited. These circuit analysis is simulated by EMTP (Electro Magnetic Transient Program). Through the circuit-elements-composed-simulator, it can be handled with as the whole system for EMP protection. This means that circuit analysis can be carried out from the prime power to vircator. It is expected to help the improvement of EMP system with vircator efficiently.","PeriodicalId":6313,"journal":{"name":"2013 Abstracts IEEE International Conference on Plasma Science (ICOPS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85795625","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":"Study of low-temperature plasma development utilizing a GPU-implemented 3D PIC/MCC simulation","authors":"A. Fierro, G. Laity, S. Beeson, J. Dickens, A. Neuber","doi":"10.1109/PLASMA.2013.6634918","DOIUrl":"https://doi.org/10.1109/PLASMA.2013.6634918","url":null,"abstract":"Summary form only given. A GPU-accelerated 3-dimensional PIC/MCC simulation code was developed using the CUDA environment to study the physical processes involved in the development of a low-temperature plasma. The simulation results aid in quantifying transient plasma development as it is often inaccessible experimentally in detail even with modern noninvasive techniques such as non-linear laser spectroscopy or high-speed electrical diagnostics. Hence, computational methods, such as Particle-in-Cell (PIC) and Monte Carlo Collision (MCC), provide a complementary approach to determining the mechanisms leading to plasma development. However, fully modeling the physics of the plasma development is made difficult by the number of plasma processes that must be tracked simultaneously, and only recently have computing resources provided the capability to track tens of millions of particle interactions. Furthermore, the introduction of graphics processing unit (GPU) computing provides an attractive means for economical and efficient parallelization of scientific codes through a framework such as NVIDIA CUDA. As such, a GPU-accelerated 3-dimensional PIC/MCC simulation was developed using the CUDA environment to provide characteristics during the initial stage of plasma development in atmospheric pressure nitrogen. The simulation was run on a NVIDIA GTX 580 with 3 GB of memory and 512 CUDA cores. The simulated geometry consists of two paraboloid electrodes with a gap distance of 5 millimeters with Dirichlet boundary conditions, and 22 unique electron interactions with molecular nitrogen are considered. The electrodes are excited with a step voltage pulse of several thousand volts also assuming a uniformly distributed initial electron density of 104 cm-3 in the volume. For instance, results from a 5 nanosecond simulation reveal the development of positive ion space charge channels near the anode and cathode regions. These channels appear consistent with high-speed streamer photographs captured during plasma formation. The electron energy distribution function (EEDF) indicates a non-Maxwellian velocity distribution during the application of the high electric field. Furthermore, a typical electron density near the cathode is on the order of 7 × 108 cm-3. The results from numerical simulation will be compared in detail to experimentally accessible parameters such as electron temperature and dissociation degree.","PeriodicalId":6313,"journal":{"name":"2013 Abstracts IEEE International Conference on Plasma Science (ICOPS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85807224","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":"PPPS-2013: Generation, detection and control of ultrafast nonlinear optical processes in high energy density plasmas using spike trains of uneven duration and delay","authors":"B. Afeyan, S. Huller, B. Albright","doi":"10.1109/PLASMA.2013.6633487","DOIUrl":"https://doi.org/10.1109/PLASMA.2013.6633487","url":null,"abstract":"Summary form only given. The success of Inertial Confinement Fusion (ICF) is to achieve controlled thermonuclear burn in the laboratory which will lead to the commercialization of clean, carbon-free and safe Inertial Fusion Energy (IFE). Both ICF and IFE demand a detailed understanding of the rapidly evolving high energy density plasmas (HEDP) as intense lasers create and nonlinearly modify them. We have developed and tested new design tools for novel ultrafast diagnostics that use nonlinear optical (NLO) techniques to ferret out the complex, nonlinear, kinetic, microscopic dynamics of HEDP. Measuring the slope of the velocity distribution function of a plasma electron or ion species in a velocity sector of interest is one such paramount goal. We accomplish this by (i) adopting the appropriate method of generating a pump laser composed of spike trains of uneven duration and delay (STUD pulses)1, 2, (ii) adopting the appropriate method of detecting and diagnosing the amplified transmission of a stimulated Raman or stimulated Brillouin scattered (SRS or SBS) probe beam, and (iii) utilizing the gain variations of the scattered signal to develop a detailed map of background plasma instabilities. This GeDeCo code is being tested using output from state of the art kinetic simulations3 to emulate the microscopic state of an HED plasma. High-repetition-rate, high-average-power future drivers of IFE will use STUD pulses in order to control undesirable instabilities adaptively.","PeriodicalId":6313,"journal":{"name":"2013 Abstracts IEEE International Conference on Plasma Science (ICOPS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85899531","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":"Properties of bipolar DC-pulsed microplasmas at intermediate pressures","authors":"Peng Tian, Sanghun Song, M. Kushner, S. Macheret","doi":"10.1109/PLASMA.2013.6633476","DOIUrl":"https://doi.org/10.1109/PLASMA.2013.6633476","url":null,"abstract":"Summary form only given. Microplasmas generated in spatially confined cavities have applications ranging from electrical switching and radical production to lighting. In these applications, there is often a tradeoff between obtaining a short response time of the plasma and maximizing plasma density, both of which optimize with higher pressure; and obtaining a uniform plasma, which optimizes with lower pressure. These scalings motivate operation at intermediate pressures, tens of Torr to 100 Torr, which by pd scaling corresponds to sizes of the micro-cavity of hundreds of microns. In many cases, the inner surfaces of the microplasma cavities are largely dielectric due to ease of fabrication or to maximize lifetime. These conditions then motivate use of some form of bipolar excitation.In this paper, we discuss results from a computational investigation of scaling of microplasmas excited by pulsed dc-bipolar waveforms with the goal of maximizing the time averaged electron density. The computational platform is the Hybrid Plasma Equipment Model, a 2-dimensional hydrodynamics model in which radiation transport, and electron and ion distributions are addressed using Monte Carlo techniques. We investigated plasmas of 10s-100s Torr excited by short DC bipolar pulses (a few ns) with pulse repetition periods ranging from tens to hundreds of ns using mixtures of rare gases. Cavity sizes are a few hundred microns. Quasi-steady state, time averaged electron densities in excess of 1015 cm-3 in Penning mixtures are predicted. Although ionization by bulk electrons is the major source, the uniformity of the plasma is sensitive to ionization due to sheath accelerated secondary electrons. The behavior of the plasma was asymmetric with respect to the polarity of the voltage pulses, with more ionization occurring on the anodic portion of the cycle, in large part due to the electrically floating dielectric boundaries.","PeriodicalId":6313,"journal":{"name":"2013 Abstracts IEEE International Conference on Plasma Science (ICOPS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78320580","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":"Room temperature direct current air plasma jet for biomedical applications","authors":"S. Wu, Z. Wang, Q. Huang, X. Lu, K. Ostrikov","doi":"10.1109/PLASMA.2013.6633324","DOIUrl":"https://doi.org/10.1109/PLASMA.2013.6633324","url":null,"abstract":"Summary form only given. Atmospheric-pressure room-temperature plasma jets are commonly used in plasma medicine, nanotechnology, as well as surface and materials processing. Most of the applications require room-temperature operation while completely avoiding the glow-to-arc transitions. To meet these requirements, the atmospheric plasma jets are usually sustained in noble gases. However, this is very challenging for the open-air operation. Moreover, the cross-sections of the plasma plumes are typically very small, which make large-area surface processing particularly difficult. One promising way to overcome this shortcoming is by using the plasma jet arrays. However, since the individual plasma plumes generated by the arrayed plasma jets are in most cases independent and do not merge in open air, it is very difficult to achieve uniform plasmas and surface treatment effects. In this paper, we demonstrate a homogenous cold air plasma glow with a large cross-section generated by a direct current power supply. There is no risk of glow-to-arc transitions, and the plasma glow appears uniform regardless of the gap between the nozzle and the surface being processed. Detailed studies show that both the position of the quartz tube and the gas flow rate affect the plasma characteristics. Further investigation indicates that the residual charges trapped on the inner surface of the quartz tube may be responsible for the generation of the air plasma plume with a large cross-section. Moreover, the spatially resolved optical emission spectroscopy reveals that the air plasma plume is uniform as it propagates out of the nozzle. The air plasma plume with remarkable improvement of the plasma uniformity is used to improve the bio-compatibility of a glass coverslip over a reasonably large area. This improvement is demonstrated by a much more uniform and effective attachment and proliferation of human embryonic kidney 293 (HEK 293) cells on the plasma-treated surface.","PeriodicalId":6313,"journal":{"name":"2013 Abstracts IEEE International Conference on Plasma Science (ICOPS)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78367793","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}