Energy coupling to the plasma in repetitive nanosecond pulse discharges

International Nuclear Information System (INIS)

Adamovich, Igor V.; Nishihara, Munetake; Choi, Inchul; Uddi, Mruthunjaya; Lempert, Walter R.

2009-01-01

A new analytic quasi-one-dimensional model of energy coupling to nanosecond pulse discharge plasmas in plane-to-plane geometry has been developed. The use of a one-dimensional approach is based on images of repetitively pulsed nanosecond discharge plasmas in dry air demonstrating that the plasma remains diffuse and uniform on a nanosecond time scale over a wide range of pressures. The model provides analytic expressions for the time-dependent electric field and electron density in the plasma, electric field in the sheath, sheath boundary location, and coupled pulse energy. The analytic model predictions are in very good agreement with numerical calculations. The model demonstrates that (i) the energy coupled to the plasma during an individual nanosecond discharge pulse is controlled primarily by the capacitance of the dielectric layers and by the breakdown voltage and (ii) the pulse energy coupled to the plasma during a burst of nanosecond pulses decreases as a function of the pulse number in the burst. This occurs primarily because of plasma temperature rise and resultant reduction in breakdown voltage, such that the coupled pulse energy varies approximately proportionally to the number density. Analytic expression for coupled pulse energy scaling has been incorporated into the air plasma chemistry model, validated previously by comparing with atomic oxygen number density measurements in nanosecond pulse discharges. The results of kinetic modeling using the modified air plasma chemistry model are compared with time-resolved temperature measurements in a repetitively pulsed nanosecond discharge in air, by emission spectroscopy, and purely rotational coherent anti-Stokes Raman spectroscopy showing good agreement.

Coupling of laser energy into plasma channels

International Nuclear Information System (INIS)

Dimitrov, D. A.; Giacone, R. E.; Bruhwiler, D. L.; Busby, R.; Cary, J. R.; Geddes, C. G. R.; Esarey, E.; Leemans, W. P.

2007-01-01

Diffractive spreading of a laser pulse imposes severe limitations on the acceleration length and maximum electron energy in the laser wake field accelerator (LWFA). Optical guiding of a laser pulse via plasma channels can extend the laser-plasma interaction distance over many Rayleigh lengths. Energy efficient coupling of laser pulses into and through plasma channels is very important for optimal LWFA performance. Results from simulation parameter studies on channel guiding using the particle-in-cell (PIC) code VORPAL [C. Nieter and J. R. Cary, J. Comput. Phys. 196, 448 (2004)] are presented and discussed. The effects that density ramp length and the position of the laser pulse focus have on coupling into channels are considered. Moreover, the effect of laser energy leakage out of the channel domain and the effects of tunneling ionization of a neutral gas on the guided laser pulse are also investigated. Power spectral diagnostics were developed and used to separate pump depletion from energy leakage. The results of these simulations show that increasing the density ramp length decreases the efficiency of coupling a laser pulse to a channel and increases the energy loss when the pulse is vacuum focused at the channel entrance. Then, large spot size oscillations result in increased energy leakage. To further analyze the coupling, a differential equation is derived for the laser spot size evolution in the plasma density ramp and channel profiles are simulated. From the numerical solution of this equation, the optimal spot size and location for coupling into a plasma channel with a density ramp are determined. This result is confirmed by the PIC simulations. They show that specifying a vacuum focus location of the pulse in front of the top of the density ramp leads to an actual focus at the top of the ramp due to plasma focusing, resulting in reduced spot size oscillations. In this case, the leakage is significantly reduced and is negligibly affected by ramp length

Mode coupling of electron plasma waves

International Nuclear Information System (INIS)

Harte, J.A.

1975-01-01

The driven coupled mode equations are derived for a two fluid, unequal temperature (T/sub e/ much greater than T/sub i/) plasma in the one-dimensional, electrostatic model and applied to the coupling of electron plasma waves. It is assumed that the electron to ion mass ratio identical with m/sub e/M/sub i// much less than 1 and eta 2 /sub ko/k lambda/sub De/ less than 1 where eta 2 /sub ko/ is the pump wave's power normalized to the plasma thermal energy, k the mode wave number and lambda/sub De/ the electron Debye length. Terms up to quadratic in pump power are retained. The equations describe the linear plasma modes oscillating at the wave number k and at ω/sub ek/, the Bohn Gross frequency, and at Ω/sub k/, the ion acoustic frequency, subject to the damping rates ν/sub ek/ and ν/sub ik/ for electrons and ions and their interactions due to intense high frequency waves E/sub k//sup l/. n/sub o/ is the background density, n/sub ik/ the fluctuating ion density, ω/sub pe/ the plasma frequency

Plasma suPAR is lowered by smoking cessation

DEFF Research Database (Denmark)

Eugen-Olsen, Jesper; Ladelund, Steen; Sørensen, Lars Tue

2016-01-01

BACKGROUND: Soluble urokinase plasminogen activator receptor (suPAR) is a stable inflammatory biomarker. In patients, suPAR is a marker of disease presence, severity and prognosis. In the general population, suPAR is predictive of disease development, such as diabetes and cardiovascular disease a...

Nonlinear charge reduction effect in strongly coupled plasmas

International Nuclear Information System (INIS)

Sarmah, D; Tessarotto, M; Salimullah, M

2006-01-01

The charge reduction effect, produced by the nonlinear Debye screening of high-Z charges occurring in strongly coupled plasmas, is investigated. An analytic asymptotic expression is obtained for the charge reduction factor (f c ) which determines the Debye-Hueckel potential generated by a charged test particle. Its relevant parametric dependencies are analysed and shown to predict a strong charge reduction effect in strongly coupled plasmas

Collisional Thermalization in Strongly Coupled Ultracold Neutral Plasmas

Science.gov (United States)

2017-01-25

calculated collisions rates in a strongly coupled plasma. From Bannasch et al., PRL 109, 185008 (2012). DISTRIBUTION A: Distribution approved for public...applicability to other plasmas.) We use a Green- Kubo relation to extract the diffusion constant from our measurements of the relaxation towards...strongly coupled systems. Our measurements (data symbols) agree with numerical calculations (solid lines) from J. Daligault, PRL 108, 225004 (2012

Training course on inductively coupled plasma spectrometry - Note

Digital Repository Service at National Institute of Oceanography (India)

Valsangkar, A.B.

TRAINING COURSE ON INDUCTIVELY COUPLED PLASMA SPECTROMETRY In the present day geological, chemical, environmental and archaeological research activities, the Inductively Coupled Plasma (ICP) Spectrometry is established as a cost-effective multi... the knowledge and advances in the analytical tools and methodologies for the benefit of the research scholars as well as professionals. National Institute of Oceanography, A.B. VALSANGKAR Dona Paula - 403 004 slip tectonics playing a major role...

Experimental measurements of Helicon wave coupling in KSTAR plasmas

Energy Technology Data Exchange (ETDEWEB)

Kim, H. J.; Wi, H. H.; Wang, S. J.; Park, S. Y.; Jeong, J. H.; Han, J. W.; Kwak, J. G.; Oh, Y. K. [National Fusion Research Institute, Daejeon (Korea, Republic of); Chun, M. H.; Yu, I. H. [Pohang Accelerator Laboratory, Pohang (Korea, Republic of)

2016-05-15

KSTAR tokamak can be a good platform to test this current drive concept because it has adequate machine parameters. Furthermore, KSTAR will have high electron beta plasmas in near future with additional ECH power. In 2015 KSTAR experiments, low-power traveling wave antenna has been designed, fabricated and installed for helicon wave coupling tests in KSTAT plasmas. In 2016 KSTAR campaign, 200 kW klystron power will be combined using three coaxial hybrid couplers and three dummy loads. High power RF will be fed into the traveling wave antenna with two coaxial feeders through two dual disk windows and 6 inch coaxial transmission line system. Current status and plan for high power helicon wave current drive system in KSTAR will be presented. Mock-up TWA antenna installed at the KSTAR reveals high couplings in both L- and H-mode plasmas. The coupling can be easily controlled by radial outer gap without degradation of plasma confinement or local gas puffing with slight decrease of plasma confinement.

Stirring Strongly Coupled Plasma

CERN Document Server

Fadafan, Kazem Bitaghsir; Rajagopal, Krishna; Wiedemann, Urs Achim

2009-01-01

We determine the energy it takes to move a test quark along a circle of radius L with angular frequency w through the strongly coupled plasma of N=4 supersymmetric Yang-Mills (SYM) theory. We find that for most values of L and w the energy deposited by stirring the plasma in this way is governed either by the drag force acting on a test quark moving through the plasma in a straight line with speed v=Lw or by the energy radiated by a quark in circular motion in the absence of any plasma, whichever is larger. There is a continuous crossover from the drag-dominated regime to the radiation-dominated regime. In the crossover regime we find evidence for significant destructive interference between energy loss due to drag and that due to radiation as if in vacuum. The rotating quark thus serves as a model system in which the relative strength of, and interplay between, two different mechanisms of parton energy loss is accessible via a controlled classical gravity calculation. We close by speculating on the implicati...

Study on spatial distribution of plasma parameters in a magnetized inductively coupled plasma

Energy Technology Data Exchange (ETDEWEB)

Cheong, Hee-Woon; Lee, Woohyun; Kim, Ji-Won; Whang, Ki-Woong, E-mail: kwhang@snu.ac.kr [Plasma Laboratory, Inter-University Semiconductor Research Center, Department of Electrical and Computer Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of); Kim, Hyuk [Samsung Electronics Co., Banwol-dong, Hwaseong 445-701 (Korea, Republic of); Park, Wanjae [Tokyo Electron Miyagi Ltd., Taiwa-cho, Kurokawa-gun, Miyagi 981-3629 (Japan)

2015-07-15

Spatial distributions of various plasma parameters such as plasma density, electron temperature, and radical density in an inductively coupled plasma (ICP) and a magnetized inductively coupled plasma (M-ICP) were investigated and compared. Electron temperature in between the rf window and the substrate holder of M-ICP was higher than that of ICP, whereas the one just above the substrate holder of M-ICP was similar to that of ICP when a weak (<8 G) magnetic field was employed. As a result, radical densities in M-ICP were higher than those in ICP and the etch rate of oxide in M-ICP was faster than that in ICP without severe electron charging in 90 nm high aspect ratio contact hole etch.

Radial Distribution Functions of Strongly Coupled Two-Temperature Plasmas

Science.gov (United States)

Shaffer, Nathaniel R.; Tiwari, Sanat Kumar; Baalrud, Scott D.

2017-10-01

We present tests of three theoretical models for the radial distribution functions (RDFs) in two-temperature strongly coupled plasmas. RDFs are useful in extending plasma thermodynamics and kinetic theory to strong coupling, but they are usually known only for thermal equilibrium or for approximate one-component model plasmas. Accurate two-component modeling is necessary to understand the impact of strong coupling on inter-species transport, e.g., ambipolar diffusion and electron-ion temperature relaxation. We demonstrate that the Seuferling-Vogel-Toeppfer (SVT) extension of the hypernetted chain equations not only gives accurate RDFs (as compared with classical molecular dynamics simulations), but also has a simple connection with the Yukawa OCP model. This connection gives a practical means to recover the structure of the electron background from knowledge of the ion-ion RDF alone. Using the model RDFs in Effective Potential Theory, we report the first predictions of inter-species transport coefficients of strongly coupled plasmas far from equilibrium. This work is supported by NSF Grant No. PHY-1453736, AFSOR Award No. FA9550-16-1-0221, and used XSEDE computational resources.

Helicon wave coupling to a chiral-plasma column

International Nuclear Information System (INIS)

Torres-Silva, H.; Reggiani, N.; Sakanaka, P.H.

1995-01-01

Inductive helicon wave coupling to a chiro-plasma column is studied numerically. In our theoretical model, the RF current distribution of the chiro-plasma is taken into account using the constitutive relations of a chiral-plasma. Computational results based on the data of present-day helicon devices are show. In particular, we discuss the role of magnetic-field-aligned electron landau damping for the helicon wave absorption. In many a see, the numerical findings can be understood reasonably in terms of the wavenumber spectra of the helicon wave dispersion relation for slow and fast wave of a chiral-plasma. In general however, the full electromagnetic treatment is necessary in order to describe and to understand the inductive coupling in the helicon wave regime. (author). 9 refs., 1 fig

Effect of single aerosol droplets on plasma impedance in the inductively coupled plasma

Energy Technology Data Exchange (ETDEWEB)

Chan, George C.-Y., E-mail: gcchan@indiana.edu; Zhu, Zhenli; Hieftje, Gary M.

2012-10-15

The impedance of an inductively coupled plasma was indirectly monitored by two different means-through a RF-probe coil placed inside the torch housing and from tapping the phase-detector signal of the impedance-matching network. During single-droplet introduction, temporal spikes in both the RF-probe coil and the phase-detector signals were readily observed, indicating a momentary change in plasma impedance. The changes in plasma impedance were found to be due solely to plasma perturbation by droplet introduction, and not to an artifact caused by imperfect automatic impedance matching. The temporal changes in plasma impedance were found to be directly proportional to the temporally integrated atomic emission of hydrogen, which is assumed in turn to be directly proportional to the volume of the introduced droplet. A small satellite droplet, with an estimated diameter of 27 {mu}m (i.e., {approx} 10 pL in volume), caused a readily measurable change in plasma impedance. By assuming that the change in RF-probe voltage is directly proportional to the variation in RF power delivered by the load coil, the instantaneous power change coupled to the plasma during single-droplet introduction was estimated. Typical increases in peak RF power and total energy coupled to the plasma, for a single 50-{mu}m droplet introduction, were thereby estimated to be around 8 to 11 W and 0.03 to 0.04 J, respectively. This impedance change was also exploited as a trigger to signal the droplet-introduction event into the plasma. This trigger signal was obtained through a combination of the RF-probe and the phase-detector signals and offered typical jitter from 1 to 2 ms. With the proper choice of a trigger threshold, no trigger misfire resulted and the achievable efficiencies of the trigger signal were 99.95, 97.18 and 74.33% for plasma forward power levels of 900, 1200, and 1500 W, respectively. The baseline noise on the RF-probe coil and the phase-detector signals, which increase with plasma

A Method to Construct Plasma with Nonlinear Density Enhancement Effect in Multiple Internal Inductively Coupled Plasmas

International Nuclear Information System (INIS)

Chen Zhipeng; Li Hong; Liu Qiuyan; Luo Chen; Xie Jinlin; Liu Wandong

2011-01-01

A method is proposed to built up plasma based on a nonlinear enhancement phenomenon of plasma density with discharge by multiple internal antennas simultaneously. It turns out that the plasma density under multiple sources is higher than the linear summation of the density under each source. This effect is helpful to reduce the fast exponential decay of plasma density in single internal inductively coupled plasma source and generating a larger-area plasma with multiple internal inductively coupled plasma sources. After a careful study on the balance between the enhancement and the decay of plasma density in experiments, a plasma is built up by four sources, which proves the feasibility of this method. According to the method, more sources and more intensive enhancement effect can be employed to further build up a high-density, large-area plasma for different applications. (low temperature plasma)

Hyperpolarizabilities of one and two electron ions under strongly coupled plasma

International Nuclear Information System (INIS)

Sen, Subhrangsu; Mandal, Puspajit; Kumar Mukherjee, Prasanta; Fricke, Burkhard

2013-01-01

Systematic investigations on the hyperpolarizabilities of hydrogen and helium like ions up to nuclear charge Z = 7 under strongly coupled plasma environment have been performed. Variation perturbation theory has been adopted to evaluate such properties for the one and two electron systems. For the two electron systems coupled Hartree-Fock theory, which takes care of partial electron correlation effects, has been utilised. Ion sphere model of the strongly coupled plasma, valid for ionic systems only, has been adopted for estimating the effect of plasma environment on the hyperpolarizability. The calculated free ion hyperpolarizability for all the systems is in good agreement with the existing data. Under confinement hyperpolarizabilities of one and two electron ions show interesting trend with respect to plasma coupling strength.

Fast Plasma from a Coaxial Gun; Plasma Rapide Produit par un Canon Coaxial; Bystraya plazma iz koaksial'nogo inzhektora; Produccion de Plasma Rapido Mediante un Inyector Coaxial

Energy Technology Data Exchange (ETDEWEB)

Marshall, J.; Henins, I. [Los Alamos Scientific Laboratory, Los Alamos, NM (United States)

1966-04-15

volume around the jet. Fast plasma is emitted in a narrow conical distribution with an open centre. The high voltage which accelerates the fast deuterohs also accelerates wall material ions if the fast plasma bombards a glass wall and evaporates it. (author) [French] Le canon coaxial utilise dans cette experience est une source de deux plasmas differents produits par des mecanismes separes. Un plasma de deuterium abondant et lent ( Tilde-Operator 10{sup 7} cm/s) est produit directement par l'interaction du type j xli ou j est le courant de plasma radial et if le champ magnetique produit par le courant d'alimentation le long de l'electrode centrale. La perturbation de courant se deplace, a travers le gaz injecte, vers l'ouverture du canon, a une vitesse d'environ 2,5 * 10{sup 7} cm/s et emmagasine de l'energie a l'arriere sous forme de champ magnetique et d'energie cinetique de plasma. Par son energie emmagasinee, le canon fonctionne comme un generateur electrique de basse impedence et de grande puissance de maniere a lancer dans le vide au-dela de l'ouverture du canon un jet de courant qui est la source de plasma rapide ( Tilde-Operator 5 x 10{sup 17} deuterons, Tilde-Operator 10{sup 8} cm/s). Le jet de courant ainsi que le plasma qu'il produit font l'objet des experiences decrites dans ce memoire. Le mecanisme de l'acceleration est complique et n'est pas parfaitement connu, mais beaucoup d'enseignements ont ete tires d'un grand nombre d'experiences dans lesquelles ont ete utilises les diagnostics suivants: boucles de captage diamagnetique externes, boucles Rogowsky sous vide, sondes electriques, electrode de captage capacitive externe, analyse de la deflection magnetique et electrostatique de particules, spectroscopic, photographie de la lumiere emise par les cibles, mesure de temps de vol avec ou sans champ de guidage, neutrons emis par le volume,du plasma par suite de la reaction d-d, etc. Il en resulte que le mecanisme d'acceleration consiste en un processus magneto

Analysis of plasma coupling with the prototype DIII-D ICRF antenna

International Nuclear Information System (INIS)

Ryan, P.M.; Hoffman, D.J.; Bigelow, T.S.; Baity, F.W.; Gardner, W.L.; Mayberry, M.J.; Rothe, K.E.

1988-01-01

Coupling to plasma in the H-mode is essential to the success of future ignited machines such as CIT. To ascertain voltage and current requirements for high-power second harmonic heating (2 MW in a 35- by 50-cm port), coupling to the DIII-D tokamak with a prototype compact loop antenna has been measured. The results show good loading for L-mode and limiter plasmas, but coupling 2 MW to an H-mode plasma demands voltages and currents near the limit of present technology. We report the technological analysis and progress that allow coupling of these power densities. 5 refs., 4 figs

Analysis of plasma coupling with the prototype DIII-D ICRF antenna

Energy Technology Data Exchange (ETDEWEB)

Ryan, P.M.; Hoffman, D.J.; Bigelow, T.S.; Baity, F.W.; Gardner, W.L.; Mayberry, M.J.; Rothe, K.E.

1988-01-01

Coupling to plasma in the H-mode is essential to the success of future ignited machines such as CIT. To ascertain voltage and current requirements for high-power second harmonic heating (2 MW in a 35- by 50-cm port), coupling to the DIII-D tokamak with a prototype compact loop antenna has been measured. The results show good loading for L-mode and limiter plasmas, but coupling 2 MW to an H-mode plasma demands voltages and currents near the limit of present technology. We report the technological analysis and progress that allow coupling of these power densities. 5 refs., 4 figs.

Electromagnetic modes in cold magnetized strongly coupled plasmas

OpenAIRE

Tkachenko, I. M.; Ortner, J.; Rylyuk, V. M.

1999-01-01

The spectrum of electromagnetic waves propagating in a strongly coupled magnetized fully ionized hydrogen plasma is found. The ion motion and damping being neglected, the influence of the Coulomb coupling on the electromagnetic spectrum is analyzed.

ICRH antenna S-matrix measurements and plasma coupling characterisation at JET

Science.gov (United States)

Monakhov, I.; Jacquet, P.; Blackman, T.; Bobkov, V.; Dumortier, P.; Helou, W.; Lerche, E.; Kirov, K.; Milanesio, D.; Maggiora, R.; Noble, C.; Contributors, JET

2018-04-01

The paper is dedicated to the characterisation of multi-strap ICRH antenna coupling to plasma. Relevance of traditional concept of coupling resistance to antennas with mutually coupled straps is revised and the importance of antenna port excitation consistency for application of the concept is highlighted. A method of antenna S-matrix measurement in presence of plasma is discussed allowing deeper insight into the problem of antenna-plasma coupling. The method is based entirely on the RF plant hardware and control facilities available at JET and it involves application of variable phasing between the antenna straps during the RF plant operations at  >100 kW. Unlike traditional techniques relying on low-power (~10 mW) network analysers, the applied antenna voltage amplitudes are relevant to practical conditions of ICRH operations; crucially, they are high enough to minimise possible effects of antenna loading non-linearity due to the RF sheath effects and other phenomena which could affect low-power measurements. The method has been successfully applied at JET to conventional 4-port ICRH antennas energised at frequencies of 33 MHz, 42 MHz and 51 MHz during L-mode plasma discharges while different gas injection modules (GIMs) were used to maintain comparable plasma densities during the pulses. The S-matrix assessment and its subsequent processing yielding ‘global’ antenna coupling resistances in conditions of equalised port maximum voltages allowed consistent description of antenna coupling to plasma at different strap phasing, operational frequencies and applied GIMs. Comprehensive experimental characterisation of mutually coupled antenna straps in presence of plasma also provided a unique opportunity for in-depth verification of TOPICA computer simulations.

Study on characteristics of coupled cavity chain filled with plasma

International Nuclear Information System (INIS)

Li Jianqing; Xiao Shu; Mo Yuanlong

2003-01-01

In this paper, by using rigorous field analysis, a coupled-cavity (CC) chain filled with plasma has been analyzed. How the hybrid wave between the cavity mode and plasma mode is formed has been studied. The periodical CC chain filled with plasma demonstrates periodical TG modes with a cutoff frequency of zero. When the plasma density increase to a large scale, the cavity mode of the CC chain overlaps the TG mode, these two modes couple with each other and form the hybrid modes. In the case of hybrid modes, the 'cold' bandwidth and the 'warm' bandwidth expand, and the coupled impedance increases about 5 times larger than that of the vacuum. As a whole, the slow wave characteristics are improved substantially due to the formation of the hybrid mode

Jeans instability of self-gravitating magnetized strongly coupled plasma

International Nuclear Information System (INIS)

Prajapati, R P; Sharma, P K; Sanghvi, R K; Chhajlani, R K

2012-01-01

We investigate the Jeans instability of self-gravitating magnetized strongly coupled plasma. The equations of the problem are formulated using the generalized hydrodynamic model and a general dispersion relation is obtained using the normal mode analysis. This dispersion relation is discussed for transverse and longitudinal mode of propagations. The modified condition of Jeans instability is obtained for magnetized strongly coupled plasma. We find that strong coupling of plasma particles modify the fundamental criterion of Jeans gravitational instability. In transverse mode it is found that Jeans instability criterion gets modified due to the presence of magnetic field, shear viscosity and fluid viscosity but in longitudinal mode it is unaffected due to the presence of magnetic field. From the curves we found that all these parameters have stabilizing influence on the growth rate of Jeans instability.

Coupling of Plasmas and Liquids

Science.gov (United States)

Lindsay, Alexander David

Plasma-liquids have exciting applications to several important socioeconomic areas, including agriculture, water treatment, and medicine. To realize their application potential, the basic physical and chemical phenomena of plasma-liquid systems must be better understood. Additionally, system designs must be optimized in order to maximize fluxes of critical plasma species to the liquid phase. With objectives to increase understanding of these systems and optimize their applications, we have performed both comprehensive modeling and experimental work. To date, models of plasma-liquids have focused on configurations where diffusion is the dominant transport process in both gas and liquid phases. However, convection plays a key role in many popular plasma source designs, including jets, corona discharges, and torches. In this dissertation, we model momentum, heat, and neutral species mass transfer in a convection-dominated system based on a corona discharge. We show that evaporative cooling produced by gas-phase convection can lead to a significant difference between gas and liquid phase bulk temperatures. Additionally, convection induced in the liquid phase by the gas phase flow substantially increases interfacial mass transfer of hydrophobic species like NO and NO2. Finally, liquid kinetic modeling suggests that concentrations of highly reactive species like OH and ONOOH are several orders of magnitude higher at the interface than in the solution bulk. Subsequent modeling has focused on coupling discharge physics with species transport at and through the interface. An assumption commonly seen in the literature is that interfacial loss coefficients of charged species like electrons are equal to unity. However, there is no experimental evidence to either deny or support this assumption. Without knowing the true interfacial behavior of electrons, we have explored the effects on key plasma-liquid variables of varying interfacial parameters like the electron and energy

Plasma edge modelling with ICRF coupling

Directory of Open Access Journals (Sweden)

Zhang Wei

2017-01-01

Full Text Available The physics of Radio-Frequency (RF wave heating in the Ion Cyclotron Range of Frequencies (ICRF in the core plasmas of fusion devices are relatively well understood while those in the Scrape-Off Layer (SOL remain still unresolved. This paper is dedicated to study the ICRF interactions with the plasma edge, mainly from the theoretical and numerical point of view, in particular with the 3D edge plasma fluid and neutral transport code EMC3-EIRENE and various wave codes. Here emphasis is given to the improvement of ICRF coupling with local gas puffing and to the ICRF induced density convection in the SOL.

Theory and simulation of laser plasma coupling

International Nuclear Information System (INIS)

Kruer, W.L.

1979-01-01

The theory and simulation of these coupling processes are considered. Particular emphasis is given to their nonlinear evolution. First a brief introduction to computer simulation of plasmas using particle codes is given. Then the absorption of light via the generation of plasma waves is considered, followed by a discussion of stimulated scattering of intense light. Finally these calculations are compared with experimental results

Modification de la surface du cuivre par implantation ionique par source plasma (IISP): applications à l’érosion cathodique dans les systèmes à arcs

OpenAIRE

Roy, F

2006-01-01

L’érosion cathodique est un phénomène bien connu qui limite la durée de vie de l’électrode négative dans les systèmes à arcs. Dans le présent mémoire, nous avons tenté de voir si la formation de précipités nanométriques d’oxyde de cuivre pouvait réduire l’érosion cathodique nécessaire au maintien de l’arc en mode thermo-champ (T-F). Les dits précipités ont été produits par implantation ionique par source plasma (IISP). Avec l’aide de techniques de caractérisation telle que la microscopie à fo...

Estradiol attenuates EGF-induced rapid uPAR mobilization and cell migration via the G-protein-coupled receptor 30 in ovarian cancer cells

DEFF Research Database (Denmark)

Henic, Emir; Noskova, Vera; Høyer-Hansen, Gunilla

2009-01-01

: rapid mobilization of uPAR from detergent-resistant domains, increased mRNA, and decreased degradation. G-protein-coupled receptor 30 (GPR30) is a newly identified membrane estrogen receptor (ER).The objective of this study was to explore the effects of 17beta-estradiol (E(2)) on uPAR expression...... for ERalpha, and quantitative polymerase chain reaction. Estradiol attenuates the stimulatory effect of EGF on cell migration and uPAR expression. Specifically, E(2) reduces the very rapid increase of detergent extractable uPAR, which occurs within minutes of EGF stimulation and probably represents...... agonist G1, mimicked the effect of E(2) on uPAR expression and cell migration. OVCAR-3 cells express mRNA for GPR30.Estradiol attenuates EGF-induced mobilization of ligated uPAR from detergent-resistant domains and subsequent migration in ovarian cancer cells. The response to various ER ligands indicates...

Effect of antenna capacitance on the plasma characteristics of an internal linear inductively coupled plasma system

International Nuclear Information System (INIS)

Lim, Jong Hyeuk; Kim, Kyong Nam; Park, Jung Kyun; Yeom, Geun Young

2008-01-01

This study examined the effect of the antenna capacitance of an inductively coupled plasma (ICP) source, which was varied using an internal linear antenna, on the electrical and plasma characteristics of the ICP source. The inductive coupling at a given rf current increased with decreasing antenna capacitance. This was caused by a decrease in the inner copper diameter of the antenna made from coaxial copper/quartz tubing, which resulted in a higher plasma density and lower plasma potential. By decreasing the diameter of the copper tube from 25 to 10 mm, the plasma density of a plasma source size of 2750x2350 mm 2 was increased from approximately 8x10 10 /cm 3 to 1.5x10 11 /cm 3 at 15 mTorr Ar and 9 kW of rf power

Collisionless coupling of a high- β expansion to an ambient, magnetized plasma. II. Experimental fields and measured momentum coupling

Science.gov (United States)

Bonde, Jeffrey; Vincena, Stephen; Gekelman, Walter

2018-04-01

The momentum coupled to a magnetized, ambient argon plasma from a high- β, laser-produced carbon plasma is examined in a collisionless, weakly coupled limit. The total electric field was measured by separately examining the induced component associated with the rapidly changing magnetic field of the high- β (kinetic β˜106), expanding plasma and the electrostatic component due to polarization of the expansion. Their temporal and spatial structures are discussed and their effect on the ambient argon plasma (thermal β˜10-2) is confirmed with a laser-induced fluorescence diagnostic, which directly probed the argon ion velocity distribution function. For the given experimental conditions, the electrostatic field is shown to dominate the interaction between the high- β expansion and the ambient plasma. Specifically, the expanding plasma couples energy and momentum into the ambient plasma by pulling ions inward against the flow direction.

Chronological study of beryllium plasma produced by a laser beam; Etude chronologique du plasma de beryllium cree par le faisceau d'un laser

Energy Technology Data Exchange (ETDEWEB)

Langer, Ph; Tonon, G; Durand, Y; Buges, J C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-07-01

We have carried out several investigations (ultrafast cinematography, visible and ultra-violet spectroscopy, interferometry, charged particle detection) on beryllium plasma produced by a ruby laser having a maximum power of 9 x 10{sup 10} watt/cm{sup 2} at the focal point of an objective with a 6,7 cm focal length. The common characteristic of all these investigations is a time resolution which is sufficient to follow changes in the plasma during the entire duration of the laser pulse. The plasma visible from - 60 ns (time zero corresponds to the top of the laser pulse) undergoes an uniform acceleration from - 30 to + 5 nanoseconds; at this moment its velocity reaches a value of 10{sup 7} cm/sec. Be{sup +}, Be{sup 2+} and Be{sup 3+} ions (corresponding to an ionisation potential of 153 eV) are emitted by the plasma as soon as it is formed and have a maximum kinetic energy of 1500 eV. The spectroscopic study of the plasma has shown the appearance of recombination lines of ionized beryllium and of lines of excited beryllium at + 70 nanoseconds and + 120 nanoseconds respectively. These lines are still visible after + 470 and + 720 nanoseconds. Interferometric measurements carried out on this plasma have shown that its electronic density is not uniform and decreases rapidly at increasing distance from the target. For example at 0.3 mm from the surface of the target the density becomes equal to 2.3 x 10{sup 18} e/cm{sup 3} and 5.5 x 10{sup 17} e/cm{sup 3} at + 20 and + 40 nanoseconds respectively. (authors) [French] Nous avons effectue plusieurs diagnostics (cinematographie ultra-rapide, spectroscopie dans le visible et dans l'ultraviolet, interferometrie, detection de particules chargees) sur le plasma de beryllium engendre par un laser a rubis delivrent au foyer d'un objectif de distance focale 6,7 cm un eclairement maximum de 9. 10{sup 10} W/cm{sup 2}. La caracteristique commune a tous ces diagnostics est une resolution temporelle suffisante qui nous permet de suivre

Bright branes for strongly coupled plasmas

International Nuclear Information System (INIS)

Mateos, David; Patino, Leonardo

2007-01-01

We use holographic techniques to study photon production in a class of finite temperature, strongly coupled, large-N c SU(N c ) quark-gluon plasmas with N f c quark flavours. Our results are valid to leading order in the electromagnetic coupling constant but non-perturbatively in the SU(N c ) interactions. The spectral function of electromagnetic currents and other related observables exhibit an interesting structure as a function of the photon frequency and the quark mass. We discuss possible implications for heavy ion collision experiments

The strongly coupled quark-gluon plasma created at RHIC

International Nuclear Information System (INIS)

Heinz, Ulrich

2009-01-01

The relativistic heavy-ion collider (RHIC) was built to re-create and study in the laboratory the extremely hot and dense matter that filled our entire universe during its first few microseconds. Its operation since June 2000 has been extremely successful, and the four large RHIC experiments have produced an impressive body of data which indeed provide compelling evidence for the formation of thermally equilibrated matter at unprecedented temperatures and energy densities-a 'quark-gluon plasma (QGP)'. A surprise has been the discovery that this plasma behaves like an almost perfect fluid, with extremely low viscosity. Theorists had expected a weakly interacting gas of quarks and gluons, but instead we seem to have created a strongly coupled plasma liquid. The experimental evidence strongly relies on a feature called 'elliptic flow' in off-central collisions, with additional support from other observations. This paper explains how we probe the strongly coupled QGP, describes the ideas and measurements which led to the conclusion that the QGP is an almost perfect liquid, and shows how they tie relativistic heavy-ion physics into other burgeoning fields of modern physics, such as strongly coupled Coulomb plasmas, ultracold systems of trapped atoms and superstring theory

Momentum Broadening in Weakly Coupled Quark-Gluon Plasma (with a view to finding the quasiparticles within liquid quark-gluon plasma)

CERN Document Server

D'Eramo, Francesco; Liu, Hong; Rajagopal, Krishna

2013-01-01

We calculate P(k_\\perp), the probability distribution for an energetic parton that propagates for a distance L through a medium without radiating to pick up transverse momentum k_\\perp, for a medium consisting of weakly coupled quark-gluon plasma. We use full or HTL self-energies in appropriate regimes, resumming each in order to find the leading large-L behavior. The jet quenching parameter \\hat q is the second moment of P(k_\\perp), and we compare our results to other determinations of this quantity in the literature, although we emphasize the importance of looking at P(k_\\perp) in its entirety. We compare our results for P(k_\\perp) in weakly coupled quark-gluon plasma to expectations from holographic calculations that assume a plasma that is strongly coupled at all length scales. We find that the shape of P(k_\\perp) at modest k_\\perp may not be very different in weakly coupled and strongly coupled plasmas, but we find that P(k_\\perp) must be parametrically larger in a weakly coupled plasma than in a strongl...

DC plasma ion implantation in an inductively coupled RF plasma

International Nuclear Information System (INIS)

Silawatshananai, C.; Matan, N.; Pakpum, C.; Pussadee, N.; Srisantitam, P.; Davynov, S.; Vilaithong, T.

2004-01-01

Various modes of plasma ion implantation have been investigated in a small inductively coupled 13.6 MHz RF plasma source. Plasma ion implantation with HVDC(up to -10 kV bias) has been investigated in order to incorporate with the conventional implantation of diamond like carbon. In this preliminary work, nitrogen ions are implanted into the stainless steel sample with a dose of 5.5 x 10 -2 cm for a short implanting time of 7 minutes without target cooling. Surface properties such as microhardness, wear rate and the friction coefficient have been improved. X-ray and SEM analyses show distinct structural changes on the surface. A combination of sheath assisted implantation and thermal diffusion may be responsible for improvement in surface properties. (orig.)

Ideal gas behavior of a strongly coupled complex (dusty) plasma.

Science.gov (United States)

Oxtoby, Neil P; Griffith, Elias J; Durniak, Céline; Ralph, Jason F; Samsonov, Dmitry

2013-07-05

In a laboratory, a two-dimensional complex (dusty) plasma consists of a low-density ionized gas containing a confined suspension of Yukawa-coupled plastic microspheres. For an initial crystal-like form, we report ideal gas behavior in this strongly coupled system during shock-wave experiments. This evidence supports the use of the ideal gas law as the equation of state for soft crystals such as those formed by dusty plasmas.

Ideal gas behavior of a strongly-coupled complex (dusty) plasma

OpenAIRE

Oxtoby, Neil P.; Griffith, Elias J.; Durniak, Céline; Ralph, Jason F.; Samsonov, Dmitry

2012-01-01

In a laboratory, a two-dimensional complex (dusty) plasma consists of a low-density ionized gas containing a confined suspension of Yukawa-coupled plastic microspheres. For an initial crystal-like form, we report ideal gas behavior in this strongly-coupled system during shock-wave experiments. This evidence supports the use of the ideal gas law as the equation of state for soft crystals such as those formed by dusty plasmas.

3-Dimensional Modeling of Capacitively and Inductively Coupled Plasma Etching Systems

Science.gov (United States)

Rauf, Shahid

2008-10-01

Low temperature plasmas are widely used for thin film etching during micro and nano-electronic device fabrication. Fluid and hybrid plasma models were developed 15-20 years ago to understand the fundamentals of these plasmas and plasma etching. These models have significantly evolved since then, and are now a major tool used for new plasma hardware design and problem resolution. Plasma etching is a complex physical phenomenon, where inter-coupled plasma, electromagnetic, fluid dynamics, and thermal effects all have a major influence. The next frontier in the evolution of fluid-based plasma models is where these models are able to self-consistently treat the inter-coupling of plasma physics with fluid dynamics, electromagnetics, heat transfer and magnetostatics. We describe one such model in this paper and illustrate its use in solving engineering problems of interest for next generation plasma etcher design. Our 3-dimensional plasma model includes the full set of Maxwell equations, transport equations for all charged and neutral species in the plasma, the Navier-Stokes equation for fluid flow, and Kirchhoff's equations for the lumped external circuit. This model also includes Monte Carlo based kinetic models for secondary electrons and stochastic heating, and can take account of plasma chemistry. This modeling formalism allows us to self-consistently treat the dynamics in commercial inductively and capacitively coupled plasma etching reactors with realistic plasma chemistries, magnetic fields, and reactor geometries. We are also able to investigate the influence of the distributed electromagnetic circuit at very high frequencies (VHF) on the plasma dynamics. The model is used to assess the impact of azimuthal asymmetries in plasma reactor design (e.g., off-center pump, 3D magnetic field, slit valve, flow restrictor) on plasma characteristics at frequencies from 2 -- 180 MHz. With Jason Kenney, Ankur Agarwal, Ajit Balakrishna, Kallol Bera, and Ken Collins.

Development of a low-cost inductively coupled argon plasma

International Nuclear Information System (INIS)

Ripson, P.A.M.

1983-01-01

The aim of this investigation is to drastically reduce running costs of an inductively coupled plasma. This is done by reducing the argon consumption from 20 l/min to about 1 l/min. First, a sample introduction system operating on 0.1 l/min of carrier argon is described. This system ensures a high ratio of plasma argon and carrier argon even at the low total argon consumptions intended. Next, the developed low consumption plasma is presented. In the proposed design, air is blown perpendicularly against the outside of the torch. A different coil has been developed to make air-cooling efficient. Preliminary data on coupling efficiency for the air-cooled plasma are presented. A similarly low argon consumption has been achieved with water as an external coolant medium. It is concluded that a cheaper alternative to the current ICP has become available. (Auth.)

Enhanced laser beam coupling to a plasma

International Nuclear Information System (INIS)

Steiger, A.D.; Woods, C.H.

1976-01-01

Density perturbations are induced in a heated plasma by means of a pair of oppositely directed, polarized laser beams of the same frequency. The wavelength of the density perturbations is equal to one half the wavelength of the laser beams. A third laser beam is linearly polarized and directed at the perturbed plasma along a line that is perpendicular to the direction of the two opposed beams. The electric field of the third beam is oriented to lie in the plane containing the three beams. The frequency of the third beam is chosen to cause it to interact resonantly with the plasma density perturbations, thereby efficiently coupling the energy of the third beam to the plasma. 10 claims, 2 figures

Wavelength scaling of laser plasma coupling

International Nuclear Information System (INIS)

Kruer, W.L.

1983-01-01

The use of shorter wavelength laser light both enhances collisional absorption and reduces deleterious collective plasma effects. Coupling processes which can be important in reactor-size targets are briefly reviewed. Simple estimates are presented for the intensity-wavelength regime in which collisional absorption is high and collective effects are minimized

SU-8 etching in inductively coupled oxygen plasma

DEFF Research Database (Denmark)

Rasmussen, Kristian Hagsted; Keller, Stephan Sylvest; Jensen, Flemming

2013-01-01

Structuring or removal of the epoxy based, photo sensitive polymer SU-8 by inductively coupled plasma reactive ion etching (ICP-RIE) was investigated as a function of plasma chemistry, bias power, temperature, and pressure. In a pure oxygen plasma, surface accumulation of antimony from the photo......-initiator introduced severe roughness and reduced etch rate significantly. Addition of SF6 to the plasma chemistry reduced the antimony surface concentration with lower roughness and higher etch rate as an outcome. Furthermore the etch anisotropy could be tuned by controlling the bias power. Etch rates up to 800 nm...

Effects of Reentry Plasma Sheath on Mutual-Coupling Property of Array Antenna

Directory of Open Access Journals (Sweden)

B. W. Bai

2015-01-01

Full Text Available A plasma sheath enveloping a reentry vehicle would cause the failure of on-board antennas, which is an important effect that contributes to the “blackout” problem. The method of replacing the on-board single antenna with the array antennas and using beamforming technology has been proposed to mitigate “blackout” problem by many other researchers. Because the plasma sheath is a reflective medium, plasma will alter the mutual coupling between array elements and degrade the beamforming performance of array antenna. In this paper, the effects of the plasma sheath on the mutual coupling properties between adjacent array elements are studied utilizing the algorithm of finite integration technique. Results show that mutual coupling coefficients of array elements are deteriorating more seriously with the decrease of collision frequency. Moreover, when electron density and collision frequency are both large, plasma sheath improves the mutual coupling property of array elements; this conclusion suggests that replacing the on-board single antenna with the array antennas and using beamforming technology can be adopted to mitigate the blackout problem in this condition.

Nonlinear wave coupling in a warm plasma in the fluid

International Nuclear Information System (INIS)

Malara, F.; Veltri, P.

1984-01-01

The general expression for nonlinear coupling between plasma modes is obtained. The nonlinear conductivity tensor is then calculated by means of the two-fluid plasma description taking into account the thermal pressure effects

A new class of strongly coupled plasmas inspired by sonoluminescence

Science.gov (United States)

Bataller, Alexander; Plateau, Guillaume; Kappus, Brian; Putterman, Seth

2014-10-01

Sonoluminescence originates in a strongly coupled plasma with a near liquid density and a temperature of ~10,000 K. This plasma is in LTE and therefore, it should be a general thermodynamic state. To test the universality of sonoluminescence, similar plasma conditions were generated using femtosecond laser breakdown in high pressure gases. Calibrated streak spectroscopy reveals both transport and thermodynamic properties of a strongly coupled plasma. A blackbody spectrum, which persists long after the exciting laser has turned off, indicates the presence of a highly ionized LTE microplasma. In parallel with sonoluminescence, this thermodynamic state is achieved via a considerable reduction in the ionization potential. We gratefully acknowledge support from DARPA MTO for research on microplasmas. We thank Brian Naranjo, Keith Weninger, Carlos Camara, Gary Williams, and John Koulakis for valuable discussions.

Effects of assistant anode on planar inductively coupled magnetized argon plasma in plasma immersion ion implantation

International Nuclear Information System (INIS)

Tang, Deli; Chu, Paul K.

2003-01-01

The enhancement of planar radio frequency (RF) inductively coupled argon plasma is studied in the presence of an assistant anode and an external magnetic field at low pressure. The influence of the assistant anode and magnetic field on the efficiency of RF power absorption and plasma parameters is investigated. An external axial magnetic field is coupled into the plasma discharge region by an external electromagnetic coil outside the discharge chamber and an assistant cylindrical anode is inserted into the discharge chamber to enhance the plasma discharge. The plasma parameters and density profile are measured by an electrostatic Langmuir probe at different magnetic fields and anode voltages. The RF power absorption by the plasma can be effectively enhanced by the external magnetic field compared with the nonmagnetized discharge. The plasma density can be further increased by the application of a voltage to the assistant anode. Owing to the effective power absorption and enhanced plasma discharge by the assistant anode in a longitudinal magnetic field, the plasma density can be enhanced by more than a factor of two. Meanwhile, the nonuniformity of the plasma density is less than 10% and it can be achieved in a process chamber with a diameter of 600 mm

High efficiency nebulization for helium inductively coupled plasma mass spectrometry

International Nuclear Information System (INIS)

Jorabchi, Kaveh; McCormick, Ryan; Levine, Jonathan A.; Liu Huiying; Nam, S.-H.; Montaser, Akbar

2006-01-01

A pneumatically-driven, high efficiency nebulizer is explored for helium inductively coupled plasma mass spectrometry. The aerosol characteristics and analyte transport efficiencies of the high efficiency nebulizer for nebulization with helium are measured and compared to the results obtained with argon. Analytical performance indices of the helium inductively coupled plasma mass spectrometry are evaluated in terms of detection limits and precision. The helium inductively coupled plasma mass spectrometry detection limits obtained with the high efficiency nebulizer at 200 μL/min are higher than those achieved with the ultrasonic nebulizer consuming 2 mL/min solution, however, precision is generally better with high efficiency nebulizer (1-4% vs. 3-8% with ultrasonic nebulizer). Detection limits with the high efficiency nebulizer at 200 μL/min solution uptake rate approach those using ultrasonic nebulizer upon efficient desolvation with a heated spray chamber followed by a Peltier-cooled multipass condenser

Impact of plasma tube wall thickness on power coupling in ICP sources

International Nuclear Information System (INIS)

Nawaz, Anuscheh; Herdrich, Georg

2009-01-01

The inductively heated plasma source at the Institute of Space Systems was investigated with respect to the wall thickness of the plasma tube using an air plasma. For this, the wall thickness of the quartz tube was reduced in steps from 2.5 to 1.25 mm. The significance of reducing the wall thickness was analyzed with respect to both the maximum allowable tube cooling power and the coupling efficiency. While the former results from thermal stresses in the tube's wall, the latter results from a minimization of magnetic field losses near the coil turns of the inductively coupled plasma (ICP) source. Analysis of the thermal stress could be validated by experimental data, i.e. the measurement of the tube cooling power when the respective tube structure failed. The coupling efficiency could be assessed qualitatively by simplified models, and the experimental data recorded show that coupling was improved far more than predicted.

Design Considerations in Capacitively Coupled Plasmas

Science.gov (United States)

Song, Sang-Heon; Ventzek, Peter; Ranjan, Alok

2015-11-01

Microelectronics industry has driven transistor feature size scaling from 10-6 m to 10-9 m during the past 50 years, which is often referred to as Moore's law. It cannot be overstated that today's information technology would not have been so successful without plasma material processing. One of the major plasma sources for the microelectronics fabrication is capacitively coupled plasmas (CCPs). The CCP reactor has been intensively studied and developed for the deposition and etching of different films on the silicon wafer. As the feature size gets to around 10 nm, the requirement for the process uniformity is less than 1-2 nm across the wafer (300 mm). In order to achieve the desired uniformity, the hardware design should be as precise as possible before the fine tuning of process condition is applied to make it even better. In doing this procedure, the computer simulation can save a significant amount of resources such as time and money which are critical in the semiconductor business. In this presentation, we compare plasma properties using a 2-dimensional plasma hydrodynamics model for different kinds of design factors that can affect the plasma uniformity. The parameters studied in this presentation include chamber accessing port, pumping port, focus ring around wafer substrate, and the geometry of electrodes of CCP.

Power dissipated - or generated - by the various excited modes in a plasma; Puissance dissipee - ou generee - par les differents modes excites dans un plasma

Energy Technology Data Exchange (ETDEWEB)

Rolland, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-07-01

The energy exchange between a plasma and a source of excitation J(r)sin(w{sub 0}t) is investigated. In order to include the case of growing waves associated with connective instabilities, this problem is treated in the context of the wave-packet theory, by writing the field as a double integral in two complex planes. the paths of the integration are defined after a separation into two classes of the root k(w) of the dispersion equation. We find that - at even in the absence of collisions - there is still a power exchange exchange, due to the spatial dispersion. Thus a connexion can be established with the kinematic theories of growing waves [1][2] and the modes generating power can be found. Moreover, the power dissipated by spatial dispersion is found to be critical with that due to Landau's effect for long waves. This confirms the kinematic character of the latter and bridges a gap between macroscopic and microscopic theories. (author) [French] On etudie les echanges d'energie entre un plasma et une source d'excitation J(r)sin(w{sub 0}t). Pour inclure le cas des ondes croissantes associees aux instabilites convectives, on traite ce probleme dans le cadre de la theorie du paquet d'ondes en definissant le champ par une integrale double dans deux plans complexes; les parcours d'integration sont precises apres avoir separe en deux classes les racines k(w) de l'equation de dispersion. On trouve que meme en l'absence de collisions, la puissance echangee n'est pas nulle, a cause de la dispersion spatiale. Ceci permet d'etablir une connexion avec les theories cinematiques des ondes croissantes [1][2], tout en precisant quels sont les modes generateurs d'energie. Par ailleurs, la puissance dissipee par dispersion spatiale se revele identique a la dissipation par effet Landau pour les grandes ondes, ce qui confirme le caractere cinematique de ce dernier et fait la jonction entre les theories microscopique et macroscopique. (auteur)

Self-organization observed in either fusion or strongly coupled plasmas

International Nuclear Information System (INIS)

Himura, Haruhiko; Sanpei, Akio

2011-01-01

If self-organization happens in the fusion plasma, the plasma alters its shape by weakening the confining magnetic field. The self-organized plasma is stable and robust, so its configuration is conserved even during transport in asymmetric magnetic fields. The self-organization of the plasma is driven by an electrostatic potential. Examples of the plasma that has such strong potential are non-neutral plasmas of pure ions or electrons and dusty plasmas. In the present paper, characteristic phenomena of strongly coupled plasmas such as particle aggregation and formation of the ordered structure are discussed. (T.I.)

Capacity-coupled multidischarge for atmospheric plasma production

International Nuclear Information System (INIS)

Mase, Hiroshi; Fujiwara, Tamiya; Sato, Noriyoshi

2003-01-01

We propose a method of plasma production by capacity-coupled multidischarge (CCMD) at atmospheric pressure. The discharge gaps in the CCMD consist of a common electrode and a number of compact electrodes (CCE) which are directly coupled with small capacitors for quenching the discharge. A simple CCE structure is provided by a cylindrical capacitor, the inner conductor of which is used as a gap electrode. A short pulse discharge is observed to appear homogeneously at each CCE. A charge transfer for the single-pulsed discharge is 10-100 times as large as that of the conventional dielectric barrier discharge. A high efficiency of ozone production has been confirmed in the CCMD using O 2 gas. A device configuration of the CCMD is quite flexible with respect to its geometrical shape and size. The CCMD could be used to produce plasmas for various kinds of industrial applications at atmospheric pressure

Multistage Coupling of Laser-Wakefield Accelerators with Curved Plasma Channels

Science.gov (United States)

Luo, J.; Chen, M.; Wu, W. Y.; Weng, S. M.; Sheng, Z. M.; Schroeder, C. B.; Jaroszynski, D. A.; Esarey, E.; Leemans, W. P.; Mori, W. B.; Zhang, J.

2018-04-01

Multistage coupling of laser-wakefield accelerators is essential to overcome laser energy depletion for high-energy applications such as TeV-level electron-positron colliders. Current staging schemes feed subsequent laser pulses into stages using plasma mirrors while controlling electron beam focusing with plasma lenses. Here a more compact and efficient scheme is proposed to realize the simultaneous coupling of the electron beam and the laser pulse into a second stage. A partly curved channel, integrating a straight acceleration stage with a curved transition segment, is used to guide a fresh laser pulse into a subsequent straight channel, while the electrons continue straight. This scheme benefits from a shorter coupling distance and continuous guiding of the electrons in plasma while suppressing transverse beam dispersion. Particle-in-cell simulations demonstrate that the electron beam from a previous stage can be efficiently injected into a subsequent stage for further acceleration while maintaining high capture efficiency, stability, and beam quality.

Inductively coupled plasma- mass spectrometry. Chapter 13

International Nuclear Information System (INIS)

Mahalingam, T.R.

1997-01-01

Inductively Coupled Plasma - Mass Spectrometry (ICP-MS) is a new technique for elemental and isotopic analysis which is currently attracting a great deal of interest. This relatively new technique has found wide applications in different fields of research viz., nuclear, geological, biological and environmental sciences

LH-power coupling in advanced tokamak plasmas in JET

International Nuclear Information System (INIS)

Joffrin, E.; Erents, K.; Gormezano, C.

2000-02-01

Lower Hybrid Current Drive (LHCD) is the most efficient tool to generate non-inductive current in tokamak plasmas. In JET, significant modifications of the current profile have been recently achieved in coupling up to 3MW of LH power in optimised shear discharges. However, the improved particle confinement during optimised shear plasmas results in a sharp decrease of the electron density in front the launcher close or below the cut-off density (ne=1.7.10 17 m -3 for f LH =37GHz) and makes difficult the coupling of the LH power. Deuterium gas near the launcher can help to improve the coupling, but has also the effect of increasing the ELM activity leading to the erosion of the internal transport barrier (ITB). Future development of lower hybrid launcher should include the constraints imposed by scenario such as the optimised shear. (author)

Diamond deposition using a planar radio frequency inductively coupled plasma

Science.gov (United States)

Bozeman, S. P.; Tucker, D. A.; Stoner, B. R.; Glass, J. T.; Hooke, W. M.

1995-06-01

A planar radio frequency inductively coupled plasma has been used to deposit diamond onto scratched silicon. This plasma source has been developed recently for use in large area semiconductor processing and holds promise as a method for scale up of diamond growth reactors. Deposition occurs in an annulus which coincides with the area of most intense optical emission from the plasma. Well-faceted diamond particles are produced when the substrate is immersed in the plasma.

Ion sampling and transport in Inductively Coupled Plasma Mass Spectrometry

Science.gov (United States)

Farnsworth, Paul B.; Spencer, Ross L.

2017-08-01

Quantitative accuracy and high sensitivity in inductively coupled plasma mass spectrometry (ICP-MS) depend on consistent and efficient extraction and transport of analyte ions from an inductively coupled plasma to a mass analyzer, where they are sorted and detected. In this review we examine the fundamental physical processes that control ion sampling and transport in ICP-MS and compare the results of theory and computerized models with experimental efforts to characterize the flow of ions through plasma mass spectrometers' vacuum interfaces. We trace the flow of ions from their generation in the plasma, into the sampling cone, through the supersonic expansion in the first vacuum stage, through the skimmer, and into the ion optics that deliver the ions to the mass analyzer. At each stage we consider idealized behavior and departures from ideal behavior that affect the performance of ICP-MS as an analytical tool.

Influencia de los parámetros de proyección por plasma atmosférico en recubrimientos de YSZ obtenidos a partir de polvos micro y nanoestructurados

Directory of Open Access Journals (Sweden)

Carpio, P.

2014-08-01

Full Text Available In the present work, the influence of atmospheric plasma spray (APS parameters on the deposition of two commercial YSZ feedstocks, one conventional and one nanostrcutured, has been studied. First the study focused on how the variability of the different parameters affects the particle behaviour during spraying. For this purpose, a sensor which enables to measure the particle temperature and velocity inside the plasma was used. Once the spraying parameters influence was known, both powders were deposited by APS onto stainless steel substrates modifying the higher influencing parameters. These coatings have been characterised and the influence of the particle behaviour on the coating microstructure and properties has been analysed. This work concludes the spraying parameters variation affects on the particle velocity and temperature inside the plasma plume and this behaviour influences, in turn but in a different way, on the final coating characteristics when using different powders (micro- and nanostructured.En el presente trabajo se ha estudiado la influencia de cada uno de los parámetros de la proyección térmica por plasma atmosférico (atmospheric plasma spraying, APS en la deposición de dos polvos comerciales de YSZ, uno convencional y otro nanoestructurado. En primer lugar se ha estudiado cómo afecta la variabilidad de los diferentes parámetros en el comportamiento de las partículas durante la proyección. Para tal fin, se ha utilizado un sensor que permite determinar la temperatura y la velocidad de las partículas en el interior del plasma. Una vez conocido cómo influyen los parámetros de proyección se han depositado ambos polvos sobre sustratos de acero inoxidable mediante APS modificando aquellos parámetros con un mayor impacto en el comportamiento de las partículas. Estos recubrimientos han sido caracterizados y se ha analizado la influencia del comportamiento de las partículas durante la proyección en la microestructura y

Plasma diagnostics using laser-excited coupled and transmission ring resonators

International Nuclear Information System (INIS)

Haas, R.A.

1976-01-01

In this paper a simple two-level laser model is used to investigate the frequency response of coupled-cavity laser interferometers. It is found that under certain circumstances, often satisfied by molecular gas lasers, the frequency response exhibits a resonant behavior. This behavior severely complicates the interpretation of coupled-cavity laser interferometer measurements of rapidly varying plasmas. To circumvent this limitation a new type of laser interferometer plasma diagnostic with significantly improved time response was developed. In this interferometer the plasma is located in one arm of a transmission ring resonator cavity that is excited by an externally positioned laser. Thus, the laser is decoupled from the interferometer cavity and the time response of the interferometer is then limited by the Q of the ring resonator cavity. This improved time response is acquired without loss of spatial resolution, but requires a more sensitive signal detector since the laser is no longer used as a detector as it is in conventional coupled-cavity laser interferometers. Thus, the new technique incorporates the speed of the Mach--Zender interferometer and the sensitivity of the coupled-cavity laser interferometer. The basic operating principles of this type of interferometer have been verified using a CO 2 laser

Equation of state of strongly coupled plasma mixtures

International Nuclear Information System (INIS)

DeWitt, H.E.

1984-01-01

Thermodynamic properties of strongly coupled (high density) plasmas of mixtures of light elements have been obtained by Monte Carlo simulations. For an assumed uniform charge background the equation of state of ionic mixtures is a simple extension of the one-component plasma EOS. More realistic electron screening effects are treated in linear response theory and with an appropriate electron dielectric function. Results have been obtained for the ionic pair distribution functions, and for the electric microfield distribution

Non-Equilibrium Modeling of Inductively Coupled RF Plasmas

Science.gov (United States)

2015-01-01

wall can be approximated with the expression for an infinite solenoid , B(r = R) = µ0NIc, where quan- tities N and Ic are the number of turns per unit...Modeling of non-equilibrium plasmas in an induc- tively coupled plasma facility. AIAA Paper 2014– 2235, 2014. 45th AIAA Plasmadynamics and Lasers ...1993. 24th Plas- madynamics and Laser Conference, Orlando, FL. [22] M. Capitelli, I. Armenise, D. Bruno, M. Caccia- tore, R. Celiberto, G. Colonna, O

Electron screening and kinetic-energy oscillations in a strongly coupled plasma

International Nuclear Information System (INIS)

Chen, Y.C.; Simien, C.E.; Laha, S.; Gupta, P.; Martinez, Y.N.; Mickelson, P.G.; Nagel, S.B.; Killian, T.C.

2004-01-01

We study equilibration of strongly coupled ions in an ultracold neutral plasma produced by photoionizing laser-cooled and trapped atoms. By varying the electron temperature, we show that electron screening modifies the equilibrium ion temperature. Even with few electrons in a Debye sphere, the screening is well described by a model using a Yukawa ion-ion potential. We also observe damped oscillations of the ion kinetic energy that are a unique feature of equilibration of a strongly coupled plasma

The strongly coupled quark-gluon plasma created at RHIC

CERN Document Server

Heinz, Ulrich W

2009-01-01

The Relativistic Heavy Ion Collider (RHIC) was built to re-create and study in the laboratory the extremely hot and dense matter that filled our entire universe during its first few microseconds. Its operation since June 2000 has been extremely successful, and the four large RHIC experiments have produced an impressive body of data which indeed provide compelling evidence for the formation of thermally equilibrated matter at unprecedented temperatures and energy densities -- a "quark-gluon plasma (QGP)". A surprise has been the discovery that this plasma behaves like an almost perfect fluid, with extremely low viscosity. Theorists had expected a weakly interacting gas of quarks and gluons, but instead we seem to have created a strongly coupled plasma liquid. The experimental evidence strongly relies on a feature called "elliptic flow" in off-central collisions, with additional support from other observations. This article explains how we probe the strongly coupled QGP, describes the ideas and measurements whi...

Characterization and modelling of microwave multi dipole plasmas. Application to multi dipolar plasma assisted sputtering; Caracterization et modelisation des plasmas micro-onde multi-dipolaires. Application a la pulverisation assistee par plasma multi-dipolaire

Energy Technology Data Exchange (ETDEWEB)

Tran, Tan Vinh [Universite Joseph Fourier/CNRS-IN2P3, 53 Avenue des Martyrs, F-38026 Grenoble (France)

2006-07-01

The scaling up of plasma processes in the low pressure range remains a question to be solved for their rise at the industrial level. One solution is the uniform distribution of elementary plasma sources where the plasma is produced via electron cyclotron resonance (ECR) coupling. These elementary plasma sources are made up of a cylindrical permanent magnet (magnetic dipole) set at the end of a coaxial microwave line. Although of simple concept, the optimisation of these dipolar plasma sources is in fact a complex problem. It requires the knowledge, on one hand, of the configurations of static magnetic fields and microwave electric fields, and, on the other hand, of the mechanisms of plasma production in the region of high intensity magnetic field (ECR condition), and of plasma diffusion. Therefore, the experimental characterisation of the operating ranges and plasma parameters has been performed by Langmuir probes and optical emission spectroscopy on different configurations of dipolar sources. At the same time, in a first analytical approach, calculations have been made on simple magnetic field configurations, motion and trajectory of electrons in these magnetic fields, and the acceleration of electrons by ECR coupling. Then, the results have been used for the validation of the numerical modelling of the electron trajectories by using a hybrid PIC (particle-in-cell) / MC (Monte Carlo) method. The experimental study has evidenced large operating domains, between 15 and 200 W of microwave power, and from 0.5 to 15 mTorr argon pressure. The analysis of plasma parameters has shown that the region of ECR coupling is localised near the equatorial plane of the magnet and dependent on magnet geometry. These characterizations, applied to a cylindrical reactor using 48 sources, have shown that densities between 10{sup 11} and 10{sup 12} cm{sup -3} could be achieved in the central part of the volume at a few mTorr argon pressures. The modelling of electron trajectories near

Some remarks on coherent nonlinear coupling of waves in plasmas

International Nuclear Information System (INIS)

Wilhelmsson, H.

1976-01-01

The analysis of nonlinear processes in plasma physics has given rise to a basic set of coupled equations. These equations describe the coherent nonlinear evolution of plasma waves. In this paper various possibilities of analysing these equations are discussed and inherent difficulties in the description of nonlinear interactions between different types of waves are pointed out. Specific examples of stimulated excitation of waves are considered. These are the parametric excitation of hybrid resonances in hot magnetized multi-ion component plasma and laser-plasma interactions. (B.D.)

Improved planar radio frequency inductively coupled plasma configuration in plasma immersion ion implantation

International Nuclear Information System (INIS)

Tang, D.L.; Fu, R.K.Y.; Tian, X.B.; Chu, P.K.

2003-01-01

Plasmas with higher density and better uniformity are produced using an improved planar radio frequency (rf) inductively coupled plasma configuration in plasma immersion ion implantation (PIII). An axial magnetic field is produced by external electromagnetic coils outside the discharge chamber. The rf power can be effectively absorbed by the plasma in the vicinity of the electron gyrofrequency due to the enhanced resonant absorption of electromagnetic waves in the whistler wave range, which can propagate nearly along the magnetic field lines thus greatly increases the plasma density. The plasma is confined by a longitudinal multipolar cusp magnetic field made of permanent magnets outside the process chamber. It can improve the plasma uniformity without significantly affecting the ion density. The plasma density can be increased from 3x10 9 to 1x10 10 cm -3 employing an axial magnetic field of several Gauss at 1000 W rf power and 5x10 -4 Torr gas pressure. The nonuniformity of the plasma density is less than 10% and can be achieved in a process chamber with a diameter of 600 mm. Since the plasma generation and process chambers are separate, plasma extinction due to the plasma sheath touching the chamber wall in high-energy PIII can be avoided. Hence, low-pressure, high-energy, and high-uniformity ion implantation can be accomplished using this setup

Approximation scheme for strongly coupled plasmas: Dynamical theory

International Nuclear Information System (INIS)

Golden, K.I.; Kalman, G.

1979-01-01

The authors present a self-consistent approximation scheme for the calculation of the dynamical polarizability α (k, ω) at long wavelengths in strongly coupled one-component plasmas. Development of the scheme is carried out in two stages. The first stage follows the earlier Golden-Kalman-Silevitch (GKS) velocity-average approximation approach, but goes much further in its application of the nonlinear fluctuation-dissipation theorem to dynamical calculations. The result is the simple expression for α (k, ω), αatsub GKSat(k, ω) 4 moment sum rule. In the second stage, the above dynamical expression is made self-consistent at long wavelengths by postulating that a decomposition of the quadratic polarizabilities in terms of linear ones, which prevails in the k → 0 limit for weak coupling, can be relied upon as a paradigm for arbitrary coupling. The result is a relatively simple quadratic integral equation for α. Its evaluation in the weak-coupling limit and its comparison with known exact results in that limit reveal that almost all important correlational and long-time effects are reproduced by our theory with very good numerical accuracy over the entire frequency range; the only significant defect of the approximation seems to be the absence of the ''dominant'' γ ln γ -1 (γ is the plasma parameter) contribution to Im α

Effect of simvastatin and ezetimibe on suPAR levels and outcomes

DEFF Research Database (Denmark)

Hodges, Gethin W; Bang, Casper N; Forman, Julie L

2018-01-01

-lowering therapy also lowers suPAR levels is unknown. METHODS: We investigated whether treatment with Simvastatin 40 mg and Ezetimibe 10 mg lowered plasma suPAR levels in 1838 patients with mild-moderate, asymptomatic aortic stenosis, included in the Simvastatin and Ezetimibe in Aortic Stenosis (SEAS) study, using...... and Ezetimibe treatment impeded the progression of the time-related increase in plasma suPAR levels. Year-1 suPAR was associated with all-cause mortality, MCE, and AVE irrespective of baseline levels (SEAS study: NCT00092677)....... cardiovascular events (MCE) composed of ischemic cardiovascular events (ICE) and aortic valve related events (AVE). RESULTS: After 4.3 years of follow-up, suPAR levels had increased by 9.2% (95% confidence interval [CI]: 7.0%-11.5%) in the placebo group, but only by 4.1% (1.9%-6.2%) in the group with lipid...

Atomic fluorescence spectrometry with the inductively coupled plasma

International Nuclear Information System (INIS)

Omenetto, N.; Winefordner, J.D.

1987-01-01

Atomic fluorescence spectrometry (AFS) is based on the radiational activation of atoms and ions produced in a suitable atomizer (ionizer) and the subsequent measurement of the resulting radiational deactivation, called fluorescence. Atomic fluorescence spectrometry has been of considerable interest to researchers in atomic spectrometry because of its use for both analytical and diagnostic purposes. Unfortunately, the analytical applications of AFS have suffered from the lack of commercial instrumentation until the recent marketing of the Baird multiple-element, hollow cathode lamp-excited inductively coupled plasma system. This chapter is concerned strictly with the use of the inductively coupled plasma (ICP) as a cell and as a source for AFS. Many of the major references concerning the ICP in analytical AFS are categorized in Table 9.1, along with several reviews and diagnostical studies. For more detailed discussions of the fundamental aspects of AFS, the reader is referred to previous reviews

Characterization and modeling of multi-dipolar microwave plasmas: application to multi-dipolar plasma assisted sputtering; Caracterisation et modelisation des plasmas micro-onde multi-dipolaires: application a la pulverisation assistee par plasma multi-dipolaire

Energy Technology Data Exchange (ETDEWEB)

Tran, T.V

2006-12-15

The scaling up of plasma processes in the low pressure range remains a question to be solved for their rise at the industrial level. One solution is the uniform distribution of elementary plasma sources where the plasma is produced via electron cyclotron resonance (ECR) coupling. These elementary plasma sources are made up of a cylindrical permanent magnet (magnetic dipole) set at the end of a coaxial microwave line. Although of simple concept, the optimisation of these dipolar plasma sources is in fact a complex problem. It requires the knowledge, on one hand, of the configurations of static magnetic fields and microwave electric fields, and, on the other hand, of the mechanisms of plasma production in the region of high intensity magnetic field (ECR condition), and of plasma diffusion. Therefore, the experimental characterisation of the operating ranges and plasma parameters has been performed by Langmuir probes and optical emission spectroscopy on different configurations of dipolar sources. At the same time, in a first analytical approach, calculations have been made on simple magnetic field configurations, motion and trajectory of electrons in these magnetic fields, and the acceleration of electrons by ECR coupling. Then, the results have been used for the validation of the numerical modelling of the electron trajectories by using a hybrid PIC (particle-in-cell) / MC (Monte Carlo) method. The experimental study has evidenced large operating domains, between 15 and 200 W of microwave power, and from 0.5 to 15 mtorr argon pressure. The analysis of plasma parameters has shown that the region of ECR coupling is localised near the equatorial plane of the magnet and dependent on magnet geometry. These characterizations, applied to a cylindrical reactor using 48 sources, have shown that densities between 10{sup 11} and 10{sup 12} cm{sup -3} could be achieved in the central part of the volume at a few mtorr argon pressures. The modelling of electron trajectories near

Equilibrium statistical mechanics of strongly coupled plasmas by numerical simulation

International Nuclear Information System (INIS)

DeWitt, H.E.

1977-01-01

Numerical experiments using the Monte Carlo method have led to systematic and accurate results for the thermodynamic properties of strongly coupled one-component plasmas and mixtures of two nuclear components. These talks are intended to summarize the results of Monte Carlo simulations from Paris and from Livermore. Simple analytic expressions for the equation of state and other thermodynamic functions have been obtained in which there is a clear distinction between a lattice-like static portion and a thermal portion. The thermal energy for the one-component plasma has a simple power dependence on temperature, (kT)/sup 3 / 4 /, that is identical to Monte Carlo results obtained for strongly coupled fluids governed by repulsive l/r/sup n/ potentials. For two-component plasmas the ion-sphere model is shown to accurately represent the static portion of the energy. Electron screening is included in the Monte Carlo simulations using linear response theory and the Lindhard dielectric function. Free energy expressions have been constructed for one and two component plasmas that allow easy computation of all thermodynamic functions

Study of optical emission spectroscopy with inductively coupled plasma torch

International Nuclear Information System (INIS)

Bauer, M.

1982-01-01

Inductively coupled plasma optical emission spectroscopy is an excellent tool for quantitative multielement trace analysis. This paper describes the performance of a computer-controlled sequential measurement system. Chemical and ionization interferences are shown to be negligible due to the characteristics of the inductively coupled plasma, spectral interferences are eliminated by using a high-resolution monochromator and computer data handling. Good accuracy is achieved for most of the interesting elements, as is shown from both an interlaboratory test and from comparison of the results of water samples from the rivers Elbe and Weser with those achieved with neutron activation and X-ray fluorescence analysis. (orig.) [de

Linear coupling of electromagnetic and Jeans modes in self-gravitating plasma streams

International Nuclear Information System (INIS)

Yaroshenko, Victoria V.; Voitenko, Yuriy; Goossens, Marcel

2002-01-01

A new mechanism of linear coupling between electromagnetic (nonpotential) and gravitational disturbances is found for oblique propagation relatively to particle streams. The general dispersion law is derived and applied to the case of two countersteaming dust beams of equal strength and quiasiperpendicular propagation. It reveals a strong linear coupling between the low-frequency aperiodically unstable electromagnetic (AEM) and the Jeans (JM) modes. The coupling is of a mode conversion type, resulting in a frequency gap in the dispersion, and thus significantly modifies the instability criteria. It is shown that, in contrast to the electrostatic case, AEM and JM coupling in streaming self-gravitating plasmas can actually appear even if the plasma frequencies of the dust species greatly exceed the corresponding Jeans frequencies

Modeling of Perpendicularly Driven Dual-Frequency Capacitively Coupled Plasma

International Nuclear Information System (INIS)

Wang Hongyu; Sun Peng; Zhao Shuangyun; Li Yang; Jiang Wei

2016-01-01

We analyzed perpendicularly configured dual-frequency (DF) capacitively coupled plasmas (CCP). In this configuration, two pairs of electrodes are arranged oppositely, and the discharging is perpendicularly driven by two radio frequency (RF) sources. Particle-in-cell/Monte Carlo (PIC/MC) simulation showed that the configuration had some advantages as this configuration eliminated some dual frequency coupling effects. Some variation and potential application of the discharging configuration is discussed briefly. (paper)

Control of plasma density distribution via wireless power transfer in an inductively coupled plasma

International Nuclear Information System (INIS)

Lee, Hee-Jin; Lee, Hyo-Chang; Kim, Young-Cheol; Chung, Chin-Wook

2013-01-01

With an enlargement of the wafer size, development of large-area plasma sources and control of plasma density distribution are required. To control the spatial distribution of the plasma density, wireless power transfer is applied to an inductively coupled plasma for the first time. An inner powered antenna and an outer resonant coil connected to a variable capacitor are placed on the top of the chamber. As the self-resonance frequency ω r of the resonant coil is adjusted, the power transfer rate from the inner powered coil to the outer resonant coil is changed and the dramatic evolution of the plasma density profile is measured. As ω r of the outer resonant coil changes from the non-resonant condition (where ω r is not the driving angular frequency ω rf ) to the resonant condition (where ω r = ω rf ), the plasma density profile evolves from a convex shape with maximal plasma density at the radial center into a concave shape with maximal plasma density in the vicinity of the resonant antenna coil. This result shows that the plasma density distribution can be successfully controlled via wireless resonance power transfer. (fast track communication)

Experiment on dust acoustic solitons in strongly coupled dusty plasma

International Nuclear Information System (INIS)

Boruah, Abhijit; Sharma, Sumita Kumari; Bailung, Heremba

2015-01-01

Dusty plasma, which contains nanometer to micrometer sized dust particles along with electrons and ions, supports a low frequency wave called Dust Acoustic wave, analogous to ion acoustic wave in normal plasma. Due to high charge and low temperature of the dust particles, dusty plasma can easily transform into a strongly coupled state when the Coulomb interaction potential energy exceeds the dust kinetic energy. Dust acoustic perturbations are excited in such strongly coupled dusty plasma by applying a short negative pulse (100 ms) of amplitude 5 - 20 V to an exciter. The perturbation steepens due to nonlinear effect and forms a solitary structure by balancing dispersion present in the medium. For specific discharge conditions, excitation amplitude above a critical value, the perturbation is found to evolve into a number of solitons. The experimental results on the excitation of multiple dust acoustic solitons in the strongly coupled regime are presented in this work. The experiment is carried out in radio frequency discharged plasma produced in a glass chamber at a pressure 0.01 - 0.1 mbar. Few layers of dust particles (∼ 5 μm in diameter) are levitated above a grounded electrode inside the chamber. Wave evolution is observed with the help of green laser sheet and recorded in a high resolution camera at high frame rate. The high amplitude soliton propagates ahead followed by smaller amplitude solitons with lower velocity. The separation between the solitons increases as time passes by. The characteristics of the observed dust acoustic solitons such as amplitude-velocity and amplitude- Mach number relationship are compared with the solutions of Korteweg-de Vries (KdV) equation. (author)

Jet quenching in a strongly coupled anisotropic plasma

Science.gov (United States)

Chernicoff, Mariano; Fernández, Daniel; Mateos, David; Trancanelli, Diego

2012-08-01

The jet quenching parameter of an anisotropic plasma depends on the relative orientation between the anisotropic direction, the direction of motion of the parton, and the direction along which the momentum broadening is measured. We calculate the jet quenching parameter of an anisotropic, strongly coupled {N} = 4 plasma by means of its gravity dual. We present the results for arbitrary orientations and arbitrary values of the anisotropy. The anisotropic value can be larger or smaller than the isotropic one, and this depends on whether the comparison is made at equal temperatures or at equal entropy densities. We compare our results to analogous calculations for the real-world quark-gluon plasma and find agreement in some cases and disagreement in others.

suPAR associates to glucose metabolic aberration during glucose stimulation in HIV-infected patients on HAART

DEFF Research Database (Denmark)

Andersen, Ove; Eugen-Olsen, Jesper; Kofoed, Kristian

2008-01-01

extend these findings by investigating the association of suPAR to glucose metabolic insufficiency during an oral glucose challenge (OGTT). METHODS: In 16 HIV-infected patients with lipodystrophy and 15 HIV-infected patients without lipodystrophy, glucose tolerance, insulin sensitivity (ISI......PAR correlated inversely with ISI(composite) and positively with 2h plasma glucose, fasting insulin secretion, fasting intact proinsulin and FFA level during the OGTT (all P...-RNA, duration of HIV infection), and dyslipidemia (plasma total cholesterol, triglyceride and free fatty acid level during the OGTT) were included, suPAR remained a significant marker of glucose tolerance and insulin sensitivity. Plasma suPAR exhibited a small CV (11%) during the 3h OGTT. CONCLUSIONS: su...

Mass spectrometric evidence for suprathermal ionization in an inductively coupled argon plasma

International Nuclear Information System (INIS)

Houk, R.S.; Svec, H.J.; Fassel, V.A.

1981-01-01

Mass spectra have been obtained of species in the axial channel of an inductively coupled argon plasma by extracting ions from the inductively coupled plasma into a vacuum system housing a quadrupole mass spectrometer. Ionization temperatures (T/sub ion/) are obtained from relative count rates of m/z-resolved ions according to two general types of ionization equilibrium considerations: (a) the radio of doubly/singly charged ions of the same element, and (b) the ratio of singly charged ions from two elements of different ionization energy. The T/sub ion/ values derived from measurement of Ar +2 /Ar + , Ba +2 /Ba + , Sr +2 /Sr + , and Cd + /I + are all greater than those expected from excitation temperatures measured by other workers. The latter three values for T/sub ion/ are in reasonable agreement with values obtained by optical spectrometry for a variety of argon inductively coupled plasmas

Capillary electrophoresis - inductively coupled plasma mass spectrometry (CE-ICPMS) coupling to assess pentavalent actinides thermodynamic constants

International Nuclear Information System (INIS)

Topin, S.; Baglan, N.; Aupiais, J.

2009-01-01

Full text: Aiming to investigate plutonium speciation at trace levels, we coupled capillary electrophoresis, a high resolution separation technique with inductively coupled plasma mass spectrometry, a detector with high sensitivity for plutonium. The research work performed to optimize the coupling is discussed based on the following criteria: the migration time, the resolution and the detection limit. The capabilities of the analytical tool are demonstrated by determining thermodynamic constants for pentavalent plutonium, and neptunium as a reference, in the presence of inorganic ligands. (author)

Purification of the gas after pyrolysis in coupled plasma-catalytic system

Directory of Open Access Journals (Sweden)

Młotek Michał

2017-12-01

Full Text Available Gliding discharge and coupled plasma-catalytic system were used for toluene conversion in a gas composition such as the one obtained during pyrolysis of biomass. The chosen catalyst was G-0117, which is an industrial catalyst for methane conversion manufactured by INS Pulawy (Poland. The effects of discharge power, initial concentration of toluene, gas flow rate and the presence of the bed of the G-0117 catalyst on the conversion of C7H8, a model tars compounds were investigated. Conversion of coluene increases with discharge power and the highest one was noted in the coupled plasma-catalytic system. It was higher than that in the homogeneous system of gliding discharge. When applying a reactor with reduced G-0117 and CO (0.15 mol%, CO2 (0.15 mol%, H2 (0.30 mol%, N2 (0.40 mol%, 4000 ppm of toluene and gas flow rate of 1.5 Nm3/h, the conversion of toluene was higher than 99%. In the coupled plasma-catalytic system with G-0117 methanation of carbon oxides was observed.

LLNL large-area inductively coupled plasma (ICP) source: Experiments

International Nuclear Information System (INIS)

Richardson, R.A.; Egan, P.O.; Benjamin, R.D.

1995-05-01

We describe initial experiments with a large (76-cm diameter) plasma source chamber to explore the problems associated with large-area inductively coupled plasma (ICP) sources to produce high density plasmas useful for processing 400-mm semiconductor wafers. Our experiments typically use a 640-nun diameter planar ICP coil driven at 13.56 MHz. Plasma and system data are taken in Ar and N 2 over the pressure range 3-50 mtorr. RF inductive power was run up to 2000W, but typically data were taken over the range 100-1000W. Diagnostics include optical emission spectroscopy, Langmuir probes, and B probes as well as electrical circuit measurements. The B and E-M measurements are compared with models based on commercial E-M codes. Initial indications are that uniform plasmas suitable for 400-mm processing are attainable

Continuum Lowering and Fermi-Surface Rising in Strongly Coupled and Degenerate Plasmas

International Nuclear Information System (INIS)

Hu, S. X.

2017-01-01

Here, continuum lowering is a well-known and important physics concept that describes the ionization potential depression (IPD) in plasmas caused by thermal-/pressure-induced ionization of outer-shell electrons. The existing IPD models are often used to characterize plasma conditions and to gauge opacity calculations. Recent precision measurements have revealed deficits in our understanding of continuum lowering in dense hot plasmas. However, these investigations have so far been limited to IPD in strongly coupled but nondegenerate plasmas. Here, we report a first-principles study of the K-edge shifting in both strongly coupled and fully degenerate carbon plasmas, with quantum molecular dynamics (QMD) calculations based on the all-electron density-functional theory (DFT). The resulted K-edge shifting versus plasma density, as a probe to the continuum lowering and the Fermi-surface rising, is found to be significantly different from predictions of existing IPD models. In contrast, a simple model of “single atom in box” (SAIB), developed in this work, accurately predicts K-edge locations as what ab-initio calculations provide.

Study of the linear and non-linear coupling of the LH wave to the tokamak plasmas

International Nuclear Information System (INIS)

Preynas, M.

2012-10-01

In order to achieve long pulse operation with a tokamak, additional heating and current drive systems are necessary. High frequency antennas, which deliver several megawatts of power to the plasma, are currently used in several tokamaks. Moreover, a good control of the coupling of the wave launched by the antenna to the edge plasma is required to optimize the efficiency of heating and current drive LH systems. However, non-linear effects which depend on the level of injected power in the plasma strongly damage the coupling of the LH wave at particular edge parameters (density and temperature profiles). Results presented in the manuscript deal with the study of the linear and non-linear coupling of the LH wave to the plasma. In the framework of the commissioning of the Passive Active Multijunction antenna in 2009 on the Tore Supra tokamak aiming at validating the LH system suggested for ITER, the characterisation of its coupling properties was realized from low power experiments. The experimental results, which are compared with the linear coupling code ALOHA, have validated the theoretical predictions of good coupling at edge plasma density around the cut-off density. Besides, the ponderomotive effect is clearly identified as responsible for the deterioration in the coupling of the wave, which is measured under particular edge plasma conditions. A theoretical model combining the coupling of the LH wave with the ponderomotive force is suggested to explain the experimental observations. Thus, a new full wave code (named PICCOLO-2D) was developed and results from simulations validate the working hypothesis of the contribution of the ponderomotive effect in the non-linear observations of LHCD coupling on Tore Supra. (author)

Jets in a strongly coupled anisotropic plasma

Energy Technology Data Exchange (ETDEWEB)

Fadafan, Kazem Bitaghsir [Shahrood University of Technology, Faculty of Physics, Shahrood (Iran, Islamic Republic of); University of Southampton, STAG Research Centre Physics and Astronomy, Southampton (United Kingdom); Morad, Razieh [University of Cape Town, Department of Physics, Rondebosch (South Africa)

2018-01-15

In this paper, we study the dynamics of the light quark jet moving through the static, strongly coupled N = 4, anisotropic plasma with and without charge. The light quark is presented by a 2-parameters point-like initial condition falling string in the context of the AdS/CFT. We calculate the stopping distance of the light quark in the anisotropic medium and compare it with its isotropic value. We study the dependency of the stopping distance to the both string initial conditions and background parameters such as anisotropy parameter or chemical potential. Although the typical behavior of the string in the anisotropic medium is similar to the one in the isotropic AdS-Sch background, the string falls faster to the horizon depending on the direction of moving. Particularly, the enhancement of quenching is larger in the beam direction. We find that the suppression of stopping distance is more prominent when the anisotropic plasma have the same temperature as the isotropic plasma. (orig.)

On coupling fluid plasma and kinetic neutral physics models

Directory of Open Access Journals (Sweden)

I. Joseph

2017-08-01

Full Text Available The coupled fluid plasma and kinetic neutral physics equations are analyzed through theory and simulation of benchmark cases. It is shown that coupling methods that do not treat the coupling rates implicitly are restricted to short time steps for stability. Fast charge exchange, ionization and recombination coupling rates exist, even after constraining the solution by requiring that the neutrals are at equilibrium. For explicit coupling, the present implementation of Monte Carlo correlated sampling techniques does not allow for complete convergence in slab geometry. For the benchmark case, residuals decay with particle number and increase with grid size, indicating that they scale in a manner that is similar to the theoretical prediction for nonlinear bias error. Progress is reported on implementation of a fully implicit Jacobian-free Newton–Krylov coupling scheme. The present block Jacobi preconditioning method is still sensitive to time step and methods that better precondition the coupled system are under investigation.

Dispersive liquid-liquid microextraction followed by flow injection-inductively coupled plasma mass spectrometry (FI-ICPMS) determination of 14 lanthanides from ground water

International Nuclear Information System (INIS)

Chandrasekaran, K.; Karunasagar, D.; Arunachalam, J.

2011-01-01

The aim of the present work was to develop a dispersive liquid-liquid microextraction (DLLME) method for the sensitive determination of REEs at a few parts per billion in groundwater by flow injection-inductively coupled plasma mass spectrometry (FI-ICPMS). In the developed method, methanol (500 μl) and chloroform (200μl) were used as the disperser and extractant respectively. The REEs were complexed with 4-(2-pyridylazo resorcinol) (PAR) at a pH of 7. Acetate ion was added as an auxiliary ligand for neutralization of the charge on the lanthanide-PAR complex. The disperser (MeOH) - extraction solvent (CHCl 3 ) mixture was rapidly injected using a disposable syringe, thereby forming a cloudy solution. The lanthanide-PAR complex was extracted into the fine droplets of the chloroform dispersed in the aqueous phase. The solution was centrifuged and the aqueous layer at the top was discarded. The REEs were back extracted from the chloroform layer with nitric acid for determination by ICPMS. Important parameters for complex formation and extraction, such as volume of extraction/disperser solvent, extraction time, pH and concentration of the chelating agent and the auxiliary ligand are being optimized using ICP-MS. The optimization is being carried out at 5 μg L -1 concentration level of REE in the initial water sample. Preliminary studies have shown an extraction recovery of 80-85% for all the 14 lanthanide elements and these will be presented

Measurements of time average series resonance effect in capacitively coupled radio frequency discharge plasma

International Nuclear Information System (INIS)

Bora, B.; Bhuyan, H.; Favre, M.; Wyndham, E.; Chuaqui, H.; Kakati, M.

2011-01-01

Self-excited plasma series resonance is observed in low pressure capacitvely coupled radio frequency discharges as high-frequency oscillations superimposed on the normal radio frequency current. This high-frequency contribution to the radio frequency current is generated by a series resonance between the capacitive sheath and the inductive and resistive bulk plasma. In this report, we present an experimental method to measure the plasma series resonance in a capacitively coupled radio frequency argon plasma by modifying the homogeneous discharge model. The homogeneous discharge model is modified by introducing a correction factor to the plasma resistance. Plasma parameters are also calculated by considering the plasma series resonances effect. Experimental measurements show that the self-excitation of the plasma series resonance, which arises in capacitive discharge due to the nonlinear interaction of plasma bulk and sheath, significantly enhances both the Ohmic and stochastic heating. The experimentally measured total dissipation, which is the sum of the Ohmic and stochastic heating, is found to increase significantly with decreasing pressure.

Effective potential kinetic theory for strongly coupled plasmas

Science.gov (United States)

Baalrud, Scott D.; Daligault, Jérôme

2016-11-01

The effective potential theory (EPT) is a recently proposed method for extending traditional plasma kinetic and transport theory into the strongly coupled regime. Validation from experiments and molecular dynamics simulations have shown it to be accurate up to the onset of liquid-like correlation parameters (corresponding to Γ ≃ 10-50 for the one-component plasma, depending on the process of interest). Here, this theory is briefly reviewed along with comparisons between the theory and molecular dynamics simulations for self-diffusivity and viscosity of the one-component plasma. A number of new results are also provided, including calculations of friction coefficients, energy exchange rates, stopping power, and mobility. The theory is also cast in the Landau and Fokker-Planck kinetic forms, which may prove useful for enabling efficient kinetic computations.

The relationship between levels of plasma-soluble urokinase plasminogen activator receptor (suPAR) and presence of migraine attack and aura.

Science.gov (United States)

Yılmaz, Nigar; Yılmaz, Mustafa; Sirin, Burcu; Yılmaztekin, Sureyya; Kutlu, Gülnihal

2017-10-01

Migraine is one of the most common types of pain associated with sterile inflammatory conditions. Soluble urokinase plasminogen activator receptor (suPAR) is a potential novel inflammatory marker. We aim to determine the association between serum values of suPAR, procalcitonin, fibrinogen, and high-sensitivity C-reactive protein (hs-CRP) and migraine disease characteristics. The study involved a total of 60 migraine patients (33 patients in the interictal period, 27 patients in the attack period) and 30 healthy individuals. The serum values of suPAR were found to be significantly higher in migraine patients in the attack period than in migraine patients in the interictal period, and in healthy individuals (p migraine with aura patients than in migraine without aura patients. When we subdivided migraine patients according to frequency of attack (attacks/month), significant differences were found between the suPAR and procalcitonin levels (measured during the attack period) of those in the frequent-attack group (4-5 or more) versus those in the less frequent attack group (less than 4). Serum levels of procalcitonin were shown to be significantly higher in migraine patients during the attack period compared with migraine patients in the interictal period and in control subjects (p = .001 for both). Significant differences were found between plasma levels of fibrinogen in migraine patients versus control subjects (p migraine patients versus the control group. These findings may show that presenting a high level of suPAR in migraine patients with attack and aura results to predisposition to occurring on the symptoms and that high levels of suPAR, procalcitonin and fibrinogen in patients with migraine result in neurogenic inflammation during migraine headaches.

Powder processing and spheroidizing with thermal inductively coupled plasma

International Nuclear Information System (INIS)

Nutsch, G.; Linke, P.; Zakharian, S.; Dzur, B.; Weiss, K.-H.

2001-01-01

Processing of advanced powder materials for the spraying industry is one of the most promising applications of the thermal RF inductively coupled plasma. By selecting the feedstock carefully and adjusting the RF plasma parameters, unique materials with high quality can be achieved. Powders injected in the hot plasma core emerge with modified shapes, morphology, crystal structure and chemical composition. Ceramic oxide powders such as Al 2 O 3 , ZrO 2 , SiO 2 are spheroidized with a high spheroidization rate. By using the RF induction plasma spheroidizing process tungsten melt carbide powders are obtained with a high spheroidization rate at high feeding rates by densification of agglomerated powders consisting of di-tungsten carbide and monocarbide with a definite composition. This kind of ball-like powders is particularly suited for wear resistant applications. (author)

Vote par sondage uniforme incorruptible

OpenAIRE

Blanchard , Nicolas

2016-01-01

International audience; Introduit en 2012 par David Chaum, le vote par sondage uniforme (random-sample voting) est un protocole de vote basé sur un choix d'une sous-population représentative , permettant de limiter les coûts tout en ayant de nombreux avantages, principalement lorsqu'il est couplé a d'autres techniques comme ThreeBallot. Nous analysons un problème de corruptibilité potentielle où les votants peuvent vendre leur vote au plus offrant et proposons une variation du protocole reméd...

Modelling of plasma-antenna coupling and non-linear radio frequency wave-plasma-wall interactions in the magnetized plasma device under ion cyclotron range of frequencies

International Nuclear Information System (INIS)

Lu, LingFeng

2016-01-01

Ion Cyclotron Resonant Heating (ICRH) by waves in 30-80 MHz range is currently used in magnetic fusion plasmas. Excited by phased arrays of current straps at the plasma periphery, these waves exist under two polarizations. The Fast Wave tunnels through the tenuous plasma edge and propagates to its center where it is absorbed. The parasitically emitted Slow Wave only exists close to the launchers. How much power can be coupled to the center with 1 A current on the straps? How do the emitted radiofrequency (RF) near and far fields interact parasitically with the edge plasma via RF sheath rectification at plasma-wall interfaces? To address these two issues simultaneously, in realistic geometry over the size of ICRH antennas, this thesis upgraded and tested the Self-consistent Sheaths and Waves for ICH (SSWICH) code. SSWICH couples self-consistently RF wave propagation and Direct Current (DC) plasma biasing via non-linear RF and DC sheath boundary conditions (SBCs) at plasma/wall interfaces. Its upgrade is full wave and was implemented in two dimensions (toroidal/radial). New SBCs coupling the two polarizations were derived and implemented along shaped walls tilted with respect to the confinement magnetic field. Using this new tool in the absence of SBCs, we studied the impact of a density decaying continuously inside the antenna box and across the Lower Hybrid (LH) resonance. Up to the memory limits of our workstation, the RF fields below the LH resonance changed with the grid size. However the coupled power spectrum hardly evolved and was only weakly affected by the density inside the box. In presence of SBCs, SSWICH-FW simulations have identified the role of the fast wave on RF sheath excitation and reproduced some key experimental observations. SSWICH-FW was finally adapted to conduct the first electromagnetic and RF-sheath 2D simulations of the cylindrical magnetized plasma device ALINE. (author) [fr

Serum/plasma methylmercury determination by isotope dilution gas chromatography-inductively coupled plasma mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Baxter, Douglas C., E-mail: douglas.baxter@alsglobal.com [ALS Scandinavia AB, Aurorum 10, 977 75 Lulea (Sweden); Faarinen, Mikko [ALS Scandinavia AB, Aurorum 10, 977 75 Lulea (Sweden); Osterlund, Helene; Rodushkin, Ilia [ALS Scandinavia AB, Aurorum 10, 977 75 Lulea (Sweden); Division of Geosciences, Lulea University of Technology, 977 87 Lulea (Sweden); Christensen, Morten [ALS Scandinavia AB, Maskinvaegen 2, 183 53 Taeby (Sweden)

2011-09-09

Highlights: {center_dot} We determine methylmercury in serum and plasma using isotope dilution calibration. {center_dot} Separation by gas chromatography and detection by inductively coupled plasma mass spectrometry. {center_dot} Data for 50 specimens provides first reference range for methylmercury in serum. {center_dot} Serum samples shown to be stable for 11 months in refrigerator. - Abstract: A method for the determination of methylmercury in plasma and serum samples was developed. The method uses isotope dilution with {sup 198}Hg-labeled methylmercury, extraction into dichloromethane, back-extraction into water, aqueous-phase ethylation, purge and trap collection, thermal desorption, separation by gas chromatography, and mercury isotope specific detection by inductively coupled plasma mass spectrometry. By spiking 2 mL sample with 1.2 ng tracer, measurements in a concentration interval of (0.007-2.9) {mu}g L{sup -1} could be performed with uncertainty amplification factors <2. A limit of quantification of 0.03 {mu}g L{sup -1} was estimated at 10 times the standard deviation of concentrations measured in preparation blanks. Within- and between-run relative standard deviations were <10% at added concentration levels of 0.14 {mu}g L{sup -1}, 0.35 {mu}g L{sup -1} and 2.8 {mu}g L{sup -1}, with recoveries in the range 82-110%. Application of the method to 50 plasma/serum samples yielded a median (mean; range) concentration of methylmercury of 0.081 (0.091; <0.03-0.19) {mu}g L{sup -1}. This is the first time methylmercury has been directly measured in this kind of specimen, and is therefore the first estimate of a reference range.

Antenna coupling study for ICWC plasma characterization in TEXTOR

Indian Academy of Sciences (India)

2015-11-27

Home; Journals; Pramana – Journal of Physics; Volume 80; Issue 1. Antenna coupling study for ICWC plasma characterization in ... Proceedings of the International Workshop/Conference on Computational Condensed Matter Physics and Materials Science (IWCCMP-2015). Posted on November 27, 2015. Guest Editors: ...

Numerical experiments on 2D strongly coupled complex plasmas

International Nuclear Information System (INIS)

Hou Lujing; Ivlev, A V; Thomas, H M; Morfill, G E

2010-01-01

The Brownian Dynamics simulation method is briefly reviewed at first and then applied to study some non-equilibrium phenomena in strongly coupled complex plasmas, such as heat transfer processes, shock wave excitation/propagation and particle trapping, by directly mimicking the real experiments.

Slow wave antenna coupling to ion Bernstein waves for plasma heating in ICRF

International Nuclear Information System (INIS)

Sy, W.N-C.; Amano, T.; Ando, R.; Fukuyama, A.; Watari, T.

1984-10-01

The coupling of ICRF power from a slow wave antenna to a plasma with finite temperature is examined theoretically and compared to an independent computer calculation. It is shown that such antennas can be highly efficient in trasferring most of the antenna power directly to ion Bernstein waves, with only a very small fraction going into fast waves. The potentiality of this coupling scheme for plasma heating in ICRF is briefly discussed. (author)

Radiation from nonlinear coupling of plasma waves

International Nuclear Information System (INIS)

Fung, S.F.

1986-01-01

The author examines the generation of electromagnetic radiation by nonlinear resonant interactions of plasma waves in a cold, uniformly magnetized plasma. In particular, he considers the up-conversion of two electrostatic wave packets colliding to produce high frequency electromagnetic radiation. Efficient conversion of electrostatic to electromagnetic wave energy occurs when the pump amplitudes approach and exceed the pump depletion threshold. Results from the inverse scattering transform analysis of the three-wave interaction equations are applied. When the wave packets are initially separated, the fully nonlinear set of coupling equations, which describe the evolution of the wave packets, can be reduced to three separate eigenvalue problems; each can be considered as a scattering problem, analogous to eh Schroedinger equation. In the scattering space, the wave packet profiles act as the scattering potentials. When the wavepacket areas approach (or exceed) π/2, the wave functions are localized (bound states) and the scattering potentials are said to contain solitons. Exchange of solitons occurs during the interaction. The transfer of solitons from the pump waves to the electromagnetic wave leads to pump depletion and the production of strong radiation. The emission of radio waves is considered by the coupling of two upper-hybrid branch wave packets, and an upper-hybrid and a lower hybrid branch wave packet

AETHER: A simulation platform for inductively coupled plasma

Energy Technology Data Exchange (ETDEWEB)

Turkoz, Emre, E-mail: emre.turkoz@boun.edu.tr; Celik, Murat

2015-04-01

An in-house code is developed to simulate the inductively coupled plasma (ICP). The model comprises the fluid, electromagnetic and transformer submodels. Fluid equations are solved to evaluate the plasma flow parameters, including the plasma and neutral densities, ion and neutral velocities, electron flux, electron temperature, and electric potential. The model relies on the ambipolar approximation and offers the evaluation of plasma parameters without solving the sheath region. The electromagnetic model handles the calculation of the electric and magnetic fields using the magnetic vector potential. The transformer model captures the effect of the matching circuit utilized in laboratory experiments for RF power deposition. The continuity and momentum equations are solved using finite volume method. The energy, electric potential, and magnetic vector potential equations are solved using finite difference method. The resulting linear systems of equations are solved with iterative solvers including Jacobi and GMRES. The code is written using the C++ programming language, it works in parallel and has graphical user interface. The model is applied to study ICP characteristics of a plasma confined within a cylindrical chamber with dielectric walls for two different power deposition cases. The results obtained from the developed model are verified using the plasma module of COMSOL Multiphysics. The model is also applied to a plasma source configuration, and it is demonstrated that there is an overall increase in the plasma potential when current is extracted from ICP with a biased wall electrode.

cAMP-secretion coupling is impaired in diabetic GK/Par rat β-cells: a defect counteracted by GLP-1.

Science.gov (United States)

Dolz, Manuel; Movassat, Jamileh; Bailbé, Danielle; Le Stunff, Hervé; Giroix, Marie-Hélène; Fradet, Magali; Kergoat, Micheline; Portha, Bernard

2011-11-01

cAMP-raising agents with glucagon-like peptide-1 (GLP-1) as the first in class, exhibit multiple actions that are beneficial for the treatment of type 2 diabetic (T2D) patients, including improvement of glucose-induced insulin secretion (GIIS). To gain additional insight into the role of cAMP in the disturbed stimulus-secretion coupling within the diabetic β-cell, we examined more thoroughly the relationship between changes in islet cAMP concentration and insulin release in the GK/Par rat model of T2D. Basal cAMP content in GK/Par islets was significantly higher, whereas their basal insulin release was not significantly different from that of Wistar (W) islets. Even in the presence of IBMX or GLP-1, their insulin release did not significantly change despite further enhanced cAMP accumulation in both cases. The high basal cAMP level most likely reflects an increased cAMP generation in GK/Par compared with W islets since 1) forskolin dose-dependently induced an exaggerated cAMP accumulation; 2) adenylyl cyclase (AC)2, AC3, and G(s)α proteins were overexpressed; 3) IBMX-activated cAMP accumulation was less efficient and PDE-3B and PDE-1C mRNA were decreased. Moreover, the GK/Par insulin release apparatus appears less sensitive to cAMP, since GK/Par islets released less insulin at submaximal cAMP levels and required five times more cAMP to reach a maximal secretion rate no longer different from W. GLP-1 was able to reactivate GK/Par insulin secretion so that GIIS became indistinguishable from that of W. The exaggerated cAMP production is instrumental, since GLP-1-induced GIIS reactivation was lost in the presence the AC blocker 2',5'-dideoxyadenosine. This GLP-1 effect takes place in the absence of any improvement of the [Ca(2+)](i) response and correlates with activation of the cAMP-dependent PKA-dependent pathway.

The Integrated Plasma Simulator: A Flexible Python Framework for Coupled Multiphysics Simulation

Energy Technology Data Exchange (ETDEWEB)

Foley, Samantha S [ORNL; Elwasif, Wael R [ORNL; Bernholdt, David E [ORNL

2011-11-01

High-fidelity coupled multiphysics simulations are an increasingly important aspect of computational science. In many domains, however, there has been very limited experience with simulations of this sort, therefore research in coupled multiphysics often requires computational frameworks with significant flexibility to respond to the changing directions of the physics and mathematics. This paper presents the Integrated Plasma Simulator (IPS), a framework designed for loosely coupled simulations of fusion plasmas. The IPS provides users with a simple component architecture into which a wide range of existing plasma physics codes can be inserted as components. Simulations can take advantage of multiple levels of parallelism supported in the IPS, and can be controlled by a high-level ``driver'' component, or by other coordination mechanisms, such as an asynchronous event service. We describe the requirements and design of the framework, and how they were implemented in the Python language. We also illustrate the flexibility of the framework by providing examples of different types of simulations that utilize various features of the IPS.

Functional speciation of metal-dissolved organic matter complexes by size exclusion chromatography coupled to inductively coupled plasma mass spectrometry and deconvolution analysis

International Nuclear Information System (INIS)

Laborda, Francisco; Ruiz-Begueria, Sergio; Bolea, Eduardo; Castillo, Juan R.

2009-01-01

High performance size exclusion chromatography coupled to inductively coupled plasma mass spectrometry (HP-SEC-ICP-MS), in combination with deconvolution analysis, has been used to obtain multielemental qualitative and quantitative information about the distributions of metal complexes with different forms of natural dissolved organic matter (DOM). High performance size exclusion chromatography coupled to inductively coupled plasma mass spectrometry chromatograms only provide continuous distributions of metals with respect to molecular masses, due to the high heterogeneity of dissolved organic matter, which consists of humic substances as well as biomolecules and other organic compounds. A functional speciation approach, based on the determination of the metals associated to different groups of homologous compounds, has been followed. Dissolved organic matter groups of homologous compounds are isolated from the aqueous samples under study and their high performance size exclusion chromatography coupled to inductively coupled plasma mass spectrometry elution profiles fitted to model Gaussian peaks, characterized by their respective retention times and peak widths. High performance size exclusion chromatography coupled to inductively coupled plasma mass spectrometry chromatograms of the samples are deconvoluted with respect to these model Gaussian peaks. This methodology has been applied to the characterization of metal-dissolved organic matter complexes in compost leachates. The most significant groups of homologous compounds involved in the complexation of metals in the compost leachates studied have been hydrophobic acids (humic and fulvic acids) and low molecular mass hydrophilic compounds. The environmental significance of these compounds is related to the higher biodegradability of the low molecular mass hydrophilic compounds and the lower mobility of humic acids. In general, the hydrophilic compounds accounted for the complexation of around 50% of the leached

Si-compatible cleaning process for graphene using low-density inductively coupled plasma.

Science.gov (United States)

Lim, Yeong-Dae; Lee, Dae-Yeong; Shen, Tian-Zi; Ra, Chang-Ho; Choi, Jae-Young; Yoo, Won Jong

2012-05-22

We report a novel cleaning technique for few-layer graphene (FLG) by using inductively coupled plasma (ICP) of Ar with an extremely low plasma density of 3.5 × 10(8) cm(-3). It is known that conventional capacitively coupled plasma (CCP) treatments destroy the planar symmetry of FLG, giving rise to the generation of defects. However, ICP treatment with extremely low plasma density is able to remove polymer resist residues from FLG within 3 min at a room temperature of 300 K while retaining the carbon sp(2)-bonding of FLG. It is found that the carrier mobility and charge neutrality point of FLG are restored to their pristine defect-free state after the ICP treatment. Considering the application of graphene to silicon-based electronic devices, such a cleaning method can replace thermal vacuum annealing, electrical current annealing, and wet-chemical treatment due to its advantages of being a low-temperature, large-area, high-throughput, and Si-compatible process.

Coupling between chip based isotachophoresis and multi-collector inductively coupled plasma mass spectrometry for separation and measurement of lanthanides

International Nuclear Information System (INIS)

Vio, Laurent; Cretier, Gerard; Rocca, Jean-Louis; Chartier, Frederic; Geertsen, Valerie; Gourgiotis, Alkiviadis; Isnard, Helene; Morin, Pierre

2012-01-01

This paper presents the conception and fabrication of a micro-system for lanthanides separation and its coupling with a multi-collector inductively coupled plasma mass spectrometer for isotope ratio measurements. The lanthanides separation is based on the isotachophoresis technique and the micro-system conception has been adapted in order to fit with glove box limitations in view of future spent nuclear fuels analysis. The micro-device was tested by using a mixture of standard solutions of natural elements and the separation of 13 lanthanides was successfully performed. The micro-device was then coupled to a multi-collector inductively coupled plasma mass spectrometer for the on-line measurements of Nd and Sm isotope ratios. The isotopes of Nd and Sm were acquired online in multi-collection mode after separation of the two elements with an injection amount of 5 ng. Results obtained on the Nd and Sm isotope ratio measurements on transient signals are presented and discussed. (authors)

Styrene and methyl methacrylate copolymer synthesized by RF inductively coupled plasma

Energy Technology Data Exchange (ETDEWEB)

Li, Z; Gillon, X; Diallo, M; Houssiau, L; Pireaux, J-J, E-mail: zhiling.li@fundp.ac.be [University of Namur (FUNDP) Research Centre in Physics of Matter and Radiation (PMR), 61, Rue de Bruxelles, 5000 Namur (Belgium)

2011-01-01

A series of random copolymers of styrene and methyl methacrylate was prepared on a silicon substrate by RF pulsed inductively coupled plasma. The plasma gas phase was investigated by optical emission spectroscopy (OES). The physico-chemical characteristics of the deposited copolymer films were analyzed by several surface techniques: X-ray photoelectron spectroscopy (XPS), Fourier-Transform infrared absorption (FT-IR), Time-of-flight secondary ion mass spectrometry (ToF-SIMS), etc. OES of the plasma and FT-IR spectra of the films are predictive: plasma emitting a higher relative benzyl radical signal results in the deposition of a more aromatic plasma polymer. The functional thin films can be deposited by selection of the co-monomers.

Inductively coupled plasma--atomic emission spectroscopy: an evaluation of the use of nitrogen--argon admixtures as plasma discharge atmospheres

International Nuclear Information System (INIS)

Zalewski, J.C.

1979-01-01

The effects of the use of nitrogen in either the plasma coolant or aerosol carrier gas flows on the physical and spectrochemical properties of the inductively coupled plasma (ICP) were examined. While the plasma operated with nitrogen in the coolant flow exhibited a stability comparable to that of the argon plasma, the use of nitrogen in the aerosol carrier gas flow resulted in a plasma that was less stable. The detection limits obtained for the three plasmas exhibited a similar trend. In addition, the use of nitrogen--argon admixtures in the plasma coolant gas flow yielded an increase in both the net analyte and the background emission intensities when the corresponding argon and nitrogen--argon plasmas were operated under various conditions. Furthermore, the effect of aluminum on the Ca II (393.4 nm) spectral line was reported for the 1000/1 Al/Ca molar ratio. At an observation height of 15 mm, the signal depressions were 4 and 14% for the nitrogen--argon and the argon plasmas, respectively. The above experimental evidence suggested that the operation of the ICP with an Ar--N 2 coolant gas might be hotter than the argon plasma currently in use in this laboratory. The demountable plasma torch designed in collaboration with K. Olson yielded detection limits for 15 elements and 19 spectral lines that were approximately within a factor of two of those obtained with the torch of fused quartz design. The design also appeared to offer a more readily initiated plasma discharge. The experimental evidence presented supports the utilization of nitrogen--argon admixtures in the plasma coolant gas flow as alternate discharge atmospheres for inductively coupled plasma--atomic emission spectroscopy. In contrast, the experimental evidence shows that there is a deterioration in both physical and spectrochemical properties of plasmas operated with a nitrogen aerosol carrier gas

Interstellar turbulence model : A self-consistent coupling of plasma and neutral fluids

International Nuclear Information System (INIS)

Shaikh, Dastgeer; Zank, Gary P.; Pogorelov, Nikolai

2006-01-01

We present results of a preliminary investigation of interstellar turbulence based on a self-consistent two-dimensional fluid simulation model. Our model describes a partially ionized magnetofluid interstellar medium (ISM) that couples a neutral hydrogen fluid to a plasma through charge exchange interactions and assumes that the ISM turbulent correlation scales are much bigger than the shock characteristic length-scales, but smaller than the charge exchange mean free path length-scales. The shocks have no influence on the ISM turbulent fluctuations. We find that nonlinear interactions in coupled plasma-neutral ISM turbulence are influenced substantially by charge exchange processes

Removal of focal segmental glomerulosclerosis (FSGS) factor suPAR using CytoSorb.

Science.gov (United States)

Schenk, Heiko; Müller-Deile, Janina; Schmitt, Roland; Bräsen, Jan Hinrich; Haller, Hermann; Schiffer, Mario

2017-12-01

Treatment of primary focal segmental glomerulosclerosis (FSGS) and its recurrence after kidney transplantation associated with rapid deterioration of kidney function remains to be challenging despite advances in immunosuppressive therapy. The presence of circulating factors has been postulated to be a pivotal player in the pathogenesis of FSGS, although suPAR and CLCF-1 have been identified as the most promising causative factors. The potential therapeutic effect of suPAR elimination in an FSGS patient using CytoSorb, a hemoadsorption device that gained attention in the cytokine elimination in septic patients, was studied. Efficiency of total plasma exchange to remove suPAR was determined. CytoSorb hemoadsorption caused a 27.33% reduction of the suPAR level in a single treatment, whereas total plasma exchange showed a suPAR level reduction of 25.12% (n = 3; 95% confidence interval, 0.2777-0.8090; P < 0.01), which may indicate therapeutic potential in the treatment of primary FSGS and its recurrence in a kidney transplant. © 2017 Wiley Periodicals, Inc.

On plasma coupling and turbulence effects in low velocity stopping

Energy Technology Data Exchange (ETDEWEB)

Kurilenkov, Yu K [Unified Institute for High Temperatures of Russian Academy of Sciences, 13/19 Izhorskaya Str., 125412 Moscow (Russian Federation); Maynard, G [Laboratoire de Physique des Gaz et des Plasmas, UMR-8578, Bat. 210, Universite Paris XI, F-91405 Orsay (France); Barriga-Carrasco, M D [Laboratoire de Physique des Gaz et des Plasmas, UMR-8578, Bat. 210, Universite Paris XI, F-91405 Orsay (France); Valuev, A A [Unified Institute for High Temperatures of Russian Academy of Sciences, 13/19 Izhorskaya Str., 125412 Moscow (Russian Federation)

2006-04-28

The problem of stopping power (SP) for projectile ions is analysed in terms of the dielectric function and effective collision frequency for moderately dense and strongly coupled plasmas (SCP). We consider several issues regarding the calculation of stopping power for correlated ensembles of particles and oscillators. In particular, effects of group (few particle) modes, transition from positive to negative dispersion and excitation of collective modes up to suprathermal level at plasma targets are addressed. Linear SP of dense suprathermal (nonlinear) plasma targets at different levels of target plasma turbulence is estimated. The force of suprathermal plasma oscillations on the projectile ions is mostly in the nature of increased frictional drag. The results obtained show the possibility of increasing low velocity stopping (up to 'turbulent' values) in comparison with losses in equilibrium dense plasma targets. Experimental conditions to create specific turbulent targets as well as some connection between stopping phenomena and SCP transport properties are discussed briefly.

On plasma coupling and turbulence effects in low velocity stopping

International Nuclear Information System (INIS)

Kurilenkov, Yu K; Maynard, G; Barriga-Carrasco, M D; Valuev, A A

2006-01-01

The problem of stopping power (SP) for projectile ions is analysed in terms of the dielectric function and effective collision frequency for moderately dense and strongly coupled plasmas (SCP). We consider several issues regarding the calculation of stopping power for correlated ensembles of particles and oscillators. In particular, effects of group (few particle) modes, transition from positive to negative dispersion and excitation of collective modes up to suprathermal level at plasma targets are addressed. Linear SP of dense suprathermal (nonlinear) plasma targets at different levels of target plasma turbulence is estimated. The force of suprathermal plasma oscillations on the projectile ions is mostly in the nature of increased frictional drag. The results obtained show the possibility of increasing low velocity stopping (up to 'turbulent' values) in comparison with losses in equilibrium dense plasma targets. Experimental conditions to create specific turbulent targets as well as some connection between stopping phenomena and SCP transport properties are discussed briefly

HAIFA: A modular, fiber-optic coupled, spectroscopic diagnostic for plasmas

International Nuclear Information System (INIS)

Ramsey, A.T.; Turner, S.L.

1987-01-01

HAIFA is a modular, multichannel, fiber optically coupled spectroscopy diagnostic for tokamak plasmas. It operates in the visible, measuring H/sub α/ radiation, the visible continuum from thermal bremsstrahlung, and selected impurity lines. HAIFA is characterized by high modularity and flexibility, good radiation resistance, high noise immunity, and low cost. Details of design, construction, and calibration are given. The analysis of visible bremsstrahlung radiation measurements to deduce the effective ionic charge in a plasma is discussed

Inductively coupled plasma mass spectrometry (ICP-MS)

International Nuclear Information System (INIS)

Shimamura, Tadashi

1997-01-01

The period of investigation for the previous general remarks on the progress of ICP-MS was from January, 1991 to September, 1993. In the investigation of this time, for the object of the Chemical Abstracts from January, 1994 to September, 1996, retrieval was carried out by using the STN International. As the key words, ICP-MS, Inductively Coupled Plasma Mass Spectrometry or Inductively Coupled Plasma Mass Spectrometer was used. The number of hit was 373 in 1994, 462 in 1995, and 356 as of September, 1996, 1191 in total. The cumulative number of the papers from 1980 to 1996 is shown. It is known how rapidly the ICP-MS has pervaded as the means of analysis. In order to cope with the enormous number of papers, this time, it was decided to do the review by limiting to the papers which were published in the main journals deeply related to analytical chemistry. As to the tendency in the last three years, it is summarized as how to overcome the spectrum interference and matrix effect in the ICP-MS and the trend of using the ICP-MS as the high sensitivity detector for separation techniques. The technical basic research of the ICP-MS on spectrum interference, sample introduction method and others and the analysis of living body samples are reported. (K.I.)

Energy exchange in strongly coupled plasmas with electron drift

International Nuclear Information System (INIS)

Akbari-Moghanjoughi, M.; Ghorbanalilu, M.

2015-01-01

In this paper, the generalized viscoelastic collisional quantum hydrodynamic model is employed in order to investigate the linear dielectric response of a quantum plasma in the presence of strong electron-beam plasma interactions. The generalized Chandrasekhar's relativistic degeneracy pressure together with the electron-exchange and Coulomb interaction effects are taken into account in order to extend current research to a wide range of plasma number density relevant to big planetary cores and astrophysical compact objects. The previously calculated shear viscosity and the electron-ion collision frequencies are used for strongly coupled ion fluid. The effect of the electron-beam velocity on complex linear dielectric function is found to be profound. This effect is clearly interpreted in terms of the wave-particle interactions and their energy-exchange according to the sign of the imaginary dielectric function, which is closely related to the wave attenuation coefficient in plasmas. Such kinetic effect is also shown to be in close connection with the stopping power of a charged-particle beam in a quantum plasma. The effect of many independent plasma parameters, such as the ion charge-state, electron beam-velocity, and relativistic degeneracy, is shown to be significant on the growing/damping of plasma instability or energy loss/gain of the electron-beam

Effect of vapor plasma on the coupling of laser radiation with aluminum targets

Energy Technology Data Exchange (ETDEWEB)

Shui, V H; Kivel, B; Weyl, G M

1978-12-01

The effect of vapor plasma on thermal and impulse coupling of laser radiation with aluminum targets is studied to understand and explain experimental data showing anomalously high coupling to 10.6-micron laser radiation. Heating of vapor by inverse bremsstrahlung absorption of laser radiation, subsequent reradiation in the uv and deep uv by ionized species, and vapor layer growth are modeled. A computer code has been developed to solve the governing equations. Major conclusions include the following: (1) vapor plasma radiative transport can be an important mechanism for laser/target coupling, (2) aluminum vapor (density times thickness) approximately equal to 10 to the 17th power/sq cm (corresponding to about 0.01 micron of target material) can result in thermal coupling coefficients of 20% or more, and (3) too much vapor reduces the net flux at the target.

Laser pulse propagation and enhanced energy coupling to fast electrons in dense plasma gradients

International Nuclear Information System (INIS)

Gray, R J; Carroll, D C; Yuan, X H; Brenner, C M; Coury, M; Quinn, M N; Tresca, O; McKenna, P; Burza, M; Wahlström, C-G; Lancaster, K L; Neely, D; Lin, X X; Li, Y T

2014-01-01

Laser energy absorption to fast electrons during the interaction of an ultra-intense (10 20 W cm −2 ), picosecond laser pulse with a solid is investigated, experimentally and numerically, as a function of the plasma density scale length at the irradiated surface. It is shown that there is an optimum density gradient for efficient energy coupling to electrons and that this arises due to strong self-focusing and channeling driving energy absorption over an extended length in the preformed plasma. At longer density gradients the laser filaments, resulting in significantly lower overall energy coupling. As the scale length is further increased, a transition to a second laser energy absorption process is observed experimentally via multiple diagnostics. The results demonstrate that it is possible to significantly enhance laser energy absorption and coupling to fast electrons by dynamically controlling the plasma density gradient. (paper)

The polarity protein Par6 is coupled to the microtubule network during molluscan early embryogenesis

Energy Technology Data Exchange (ETDEWEB)

Homma, Taihei [Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Shimizu, Miho [Kuroda Chiromorphology Team, ERATO-SORST, JST, Komaba, Meguro-ku, Tokyo 153-8902 (Japan); Kuroda, Reiko, E-mail: ckuroda@mail.ecc.u-tokyo.ac.jp [Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Kuroda Chiromorphology Team, ERATO-SORST, JST, Komaba, Meguro-ku, Tokyo 153-8902 (Japan); Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902 (Japan)

2011-01-07

Research highlights: {yields} The cDNAs encoding Par6 and aPKC homologues were cloned from the snail Lymnaea stagnalis. {yields} L. stagnalis Par6 directly interacts with tubulin and microtubules and localizes to the microtubule cytoskeleton during the early embryogenesis. {yields} Identical sequence and localization of LsPar6 for the dextral and the sinistral snails exclude the possibility of the gene being the primary determinant of body handedness. -- Abstract: Cell polarity, which directs the orientation of asymmetric cell division and segregation of fate determinants, is a fundamental feature of development and differentiation. Regulators of polarity have been extensively studied, and the critical importance of the Par (partitioning-defective) complex as the polarity machinery is now recognized in a wide range of eukaryotic systems. The Par polarity module is evolutionarily conserved, but its mechanism and cooperating factors vary among different systems. Here we describe the cloning and characterization of a pond snail Lymnaea stagnalis homologue of partitioning-defective 6 (Lspar6). The protein product LsPar6 shows high affinity for microtubules and localizes to the mitotic apparatus during embryonic cell division. In vitro assays revealed direct binding of LsPar6 to tubulin and microtubules, which is the first evidence of the direct interaction between the two proteins. The interaction is mediated by two distinct regions of LsPar6 both located in the N-terminal half. Atypical PKC, a functional partner of Par6, was also found to localize to the mitotic spindle. These results suggest that the L. stagnalis Par complex employs the microtubule network in cell polarity processes during the early embryogenesis. Identical sequence and localization of LsPar6 for the dextral and the sinistral snails exclude the possibility of the gene being the primary determinant of handedness.

The polarity protein Par6 is coupled to the microtubule network during molluscan early embryogenesis

International Nuclear Information System (INIS)

Homma, Taihei; Shimizu, Miho; Kuroda, Reiko

2011-01-01

Research highlights: → The cDNAs encoding Par6 and aPKC homologues were cloned from the snail Lymnaea stagnalis. → L. stagnalis Par6 directly interacts with tubulin and microtubules and localizes to the microtubule cytoskeleton during the early embryogenesis. → Identical sequence and localization of LsPar6 for the dextral and the sinistral snails exclude the possibility of the gene being the primary determinant of body handedness. -- Abstract: Cell polarity, which directs the orientation of asymmetric cell division and segregation of fate determinants, is a fundamental feature of development and differentiation. Regulators of polarity have been extensively studied, and the critical importance of the Par (partitioning-defective) complex as the polarity machinery is now recognized in a wide range of eukaryotic systems. The Par polarity module is evolutionarily conserved, but its mechanism and cooperating factors vary among different systems. Here we describe the cloning and characterization of a pond snail Lymnaea stagnalis homologue of partitioning-defective 6 (Lspar6). The protein product LsPar6 shows high affinity for microtubules and localizes to the mitotic apparatus during embryonic cell division. In vitro assays revealed direct binding of LsPar6 to tubulin and microtubules, which is the first evidence of the direct interaction between the two proteins. The interaction is mediated by two distinct regions of LsPar6 both located in the N-terminal half. Atypical PKC, a functional partner of Par6, was also found to localize to the mitotic spindle. These results suggest that the L. stagnalis Par complex employs the microtubule network in cell polarity processes during the early embryogenesis. Identical sequence and localization of LsPar6 for the dextral and the sinistral snails exclude the possibility of the gene being the primary determinant of handedness.

Low-pressure water-cooled inductively coupled plasma torch

Science.gov (United States)

Seliskar, Carl J.; Warner, David K.

1988-12-27

An inductively coupled plasma torch is provided which comprises an inner tube, including a sample injection port to which the sample to be tested is supplied and comprising an enlarged central portion in which the plasma flame is confined; an outer tube surrounding the inner tube and containing water therein for cooling the inner tube, the outer tube including a water inlet port to which water is supplied and a water outlet port spaced from the water inlet port and from which water is removed after flowing through the outer tube; and an r.f. induction coil for inducing the plasma in the gas passing into the tube through the sample injection port. The sample injection port comprises a capillary tube including a reduced diameter orifice, projecting into the lower end of the inner tube. The water inlet is located at the lower end of the outer tube and the r.f. heating coil is disposed around the outer tube above and adjacent to the water inlet.

Detection, in real time, of metallic pollutants present in the industrial atmospheric effluents by inductively coupled plasma torch; Detection, en temps reel, d'elements metalliques presents dans les rejets atmospheriques industriels par torche a plasma a couplage inductif

Energy Technology Data Exchange (ETDEWEB)

Vacher, D.

2001-12-15

This work is devoted to the development of a process of detection in real time of metallic pollutants present in industrial atmospheric effluents. The method of measurement is the atomic spectrometry of emission coupled to an ICP torch (Inductively coupled Plasma). The technology of the fluidized beds is used as system of introduction of the metallic particles into the ICP torch, the interest of the principle of detection resting on the stamping from the usual procedure of calibration of the analytical system. The results are presented in two parts. The first relates to the diagnosis of plasmas formed with various mixtures of N{sub 2}/O{sub 2} which one corresponds to pure air, the second presents the setting process of detection in real time starting from the intensities ratios of the spectral lines of the metallic element with those of the plasma-producing element (argon or pure air) The study of the diagnosis of plasmas made up of mixtures N{sub 2}/O{sub 2} relates to the determination of the atomic excitation temperature from the spectral lines of the copper element and the evaluation of the thermal disequilibrium q Te/Th. This last is obtained by considering the mass enthalpy of various mixtures N{sub 2}/O{sub 2}. The existence of a small thermal disequilibrium is highlighted. The study of detection in real time by ICP torch, without calibration of the system, is based on three points: - spectroscopic data processing to determine the values of the intensities ratios of spectral lines; - the insertion of the intensities ratios and the characteristics of plasma (argon or pure air) into a calculation code of plasma composition; - the comparison of the mass flux values of the metallic pollutants, in real time, obtained by experiments with those resulting from the elutriation calculation, term which defines the phenomenon of entrainment of the particles out of the fluidized bed. The results made it possible to show the similarity of the analytical system response

A tightly coupled non-equilibrium model for inductively coupled radio-frequency plasmas

International Nuclear Information System (INIS)

Munafò, A.; Alfuhaid, S. A.; Panesi, M.; Cambier, J.-L.

2015-01-01

The objective of the present work is the development of a tightly coupled magneto-hydrodynamic model for inductively coupled radio-frequency plasmas. Non Local Thermodynamic Equilibrium (NLTE) effects are described based on a hybrid State-to-State approach. A multi-temperature formulation is used to account for thermal non-equilibrium between translation of heavy-particles and vibration of molecules. Excited electronic states of atoms are instead treated as separate pseudo-species, allowing for non-Boltzmann distributions of their populations. Free-electrons are assumed Maxwellian at their own temperature. The governing equations for the electro-magnetic field and the gas properties (e.g., chemical composition and temperatures) are written as a coupled system of time-dependent conservation laws. Steady-state solutions are obtained by means of an implicit Finite Volume method. The results obtained in both LTE and NLTE conditions over a broad spectrum of operating conditions demonstrate the robustness of the proposed coupled numerical method. The analysis of chemical composition and temperature distributions along the torch radius shows that: (i) the use of the LTE assumption may lead to an inaccurate prediction of the thermo-chemical state of the gas, and (ii) non-equilibrium phenomena play a significant role close the walls, due to the combined effects of Ohmic heating and macroscopic gradients

Coupled two-dimensional edge-plasma and neutral gas modelling of the DIII-D scrape-off-layer

International Nuclear Information System (INIS)

Maingi, R.; Gilligan, J.; Hankins, O.; Rensink, M.; Owen, L.; Klepper, C.; Mioduszewski, P.

1992-01-01

This paper reports that in order to do consistent scrape-off-layer plasma and neutral transport calculations, the 2-D fluid code, B2 has been externally coupled to the neutral transport code, DEGAS, for Dlll-D. The coupling procedure is similar to recent simulations done for TFTR, Tore Supra, and ClT. An averaged source approach is utilized to allow convergence between the two codes. Initial comparison of plasma quantities between the coupled code set and the B2 code alone shows that a colder, denser plasma may exist at the divertor targets than predicted by the B2 code with its internal recycling model

Titanium oxidation by rf inductively coupled plasma

International Nuclear Information System (INIS)

Valencia-Alvarado, R; López-Callejas, R; Barocio, S R; Mercado-Cabrera, A; Peña-Eguiluz, R; Muñoz-Castro, A E; Rodríguez-Méndez, B G; De la Piedad-Beneitez, A; De la Rosa-Vázquez, J M

2014-01-01

The development of titanium dioxide (TiO 2 ) films in the rutile and anatase phases is reported. The films have been obtained from an implantation/diffusion and sputtering process of commercially pure titanium targets, carried out in up to 500 W plasmas. The experimental outcome is of particular interest, in the case of anatase, for atmospheric pollution degradation by photocatalysis and, as to the rutile phase, for the production of biomaterials required by prosthesis and implants. The reactor employed consists in a cylindrical pyrex-like glass vessel inductively coupled to a 13.56 MHz RF source. The process takes place at a 5×10 −2 mbar pressure with the target samples being biased from 0 to -3000 V DC. The anatase phase films were obtained from sputtering the titanium targets over glass and silicon electrically floated substrates placed 2 cm away from the target. The rutile phase was obtained by implantation/diffusion on targets at about 700 °C. The plasma was developed from a 4:1 argon/oxygen mixture for ∼5 hour processing periods. The target temperature was controlled by means of the bias voltage and the plasma source power. The obtained anatase phases did not require annealing after the plasma oxidation process. The characterization of the film samples was conducted by means of x-ray diffraction, scanning electron microscopy, x-ray photoelectron spectroscopy and Raman spectroscopy

Maintenance of the resonance in a cavity filled with a variable density plasma; Entretien de la resonance d'une cavite chargee par un plasma de densite variable

Energy Technology Data Exchange (ETDEWEB)

Melin, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1969-07-01

A study has been made of the possibility of keeping in resonance a cavity filled with a plasma of variable density; only the low HF power zone has been examined (less than a few dozen W). A calculation is first made, for the chosen experimental conditions, of the slipping of the resonance frequency of a cavity as a function of the plasma parameters (density, temperature), with a view to obtaining an idea of its importance. A description is then given of the experimental set-up: the S band cavity (3000 Mc/sec) is supplied by a carcinotron type generator; use is made of the plasma of a positive column whose density ({approx}10{sup 11} cm{sup -3}) can easily be controlled so as to obtain slipping of the cavity frequency ({delta}F{sub max} {approx} 50 Mc/s). The zone of automatic agreement thus obtained for the S band is 3 per cent continuously ({approx}100 Mc/s) and 1 per cent ({approx}30 Mc/s) with a response time of 10 {mu}s (sudden changes in density, {delta}n {approx} 5.10{sup 10} cm{sup 3}). These characteristics already compare very favorably with existing systems, and can easily be improved. (author) [French] On etudie une possibilite de maintenir a la resonance une cavite chargee par un plasma dont la densite varie; on se limite au domaine des puissances HF faibles (< quelques dizaines de W). On calcule tout d'abord, pour les conditions experimentales choisies, le glissement de la frequence de resonance d'une cavite en fonction des parametres du plasma, densite, temperature, pour en evaluer les ordres de grandeur. On decrit ensuite la realisation experimentale: la cavite bande S (3000 Mc/s) est alimentee par un generateur du type carcinotron; on utilise le plasma d'une colonne positive, dont on controle facilement la densite ({approx}10{sup 11} cm{sup -3}) pour faire glisser en frequence la cavite ({delta}F{sub max} {approx} 50 Mc/s). La zone d'accord automatique obtenue ainsi pour la bande S est de 3 pour cent en continu ({approx}100 Mc/s), de 1 pour cent

Ratio of bulk to shear viscosity in a quasigluon plasma: from weak to strong coupling

CERN Document Server

Bluhm, M; Redlich, K

2012-01-01

The ratio of bulk to shear viscosity is expected to exhibit a different behaviour in weakly and in strongly coupled systems. This can be expressed by the dependence of the ratio on the squared sound velocity. In the high temperature QCD plasma at small running coupling, the viscosity ratio is uniquely determined by a quadratic dependence on the conformality measure, whereas in certain strongly coupled and nearly conformal theories this dependence is linear. Employing an effective kinetic theory of quasiparticle excitations with medium-modified dispersion relation, we analyze the ratio of bulk to shear viscosity of the gluon plasma. We show that in this approach the viscosity ratio comprises both dependencies found by means of weak coupling perturbative and strong coupling holographic techniques.

Study of plasma parameters influencing fractionation in laser ablation-inductively coupled plasma-mass spectrometry

Science.gov (United States)

Gäckle, M.; Merten, D.

2010-12-01

Methods permitting to test the influence of the matrix as well as of its local and temporal distribution on the plasma conditions in laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS) are developed. For this purpose, the MS interface is used as plasma probe allowing to investigate the average plasma condition within the ICP zone observed in terms of temporal and spatial distribution of the matrix. Inserted matrix particles, particularly when being atomized and ionized, can cause considerable changes in both electron density and plasma temperature thus influencing the ionization equilibrium of the individual analytes. In this context, the plasma probe covers a region of the plasma for which no local thermodynamic equilibrium can be assumed. The differences in temperature, identified within the region of the plasma observed, amounted up to 3000 K. While in the central region conditions were detected that would not allow efficient atomization and ionization of the matrix, these conditions improve considerably towards the margin of the area observed. Depending on the nature as well as on the temporally and locally variable density of the matrix, this can lead to varying intensity ratios of the analytes and explain fractionation effects. By means of a derived equation it is shown that the deviation of the intensity ratio from the concentration ratio turns out to be more serious the higher the difference of the ionization potential of the analytes observed, the lower the plasma temperature and the higher the matrix concentration within the area observed.

Effect of low-frequency power on dual-frequency capacitively coupled plasmas

International Nuclear Information System (INIS)

Yuan, Q H; Xin, Y; Huang, X J; Sun, K; Ning, Z Y; Yin, G Q

2008-01-01

In low-pressure dual-frequency capacitively coupled plasmas driven with 60/13.56 MHz, the effect of low-frequency power on the plasma characteristics was investigated using a compensated Langmuir electrostatic probe. At lower pressures (about 10 mTorr), it was possible to control the plasma density and the ion bombardment energy independently. As the pressure increased, this independent control could not be achieved. As the low-frequency power increased for the fixed high-frequency power, the electron energy probability function (EEPF) changed from Druyvesteyn-like to Maxwellian-like at pressures of 50 mTorr and higher, along with a drop in electron temperature. The plasma parameters were calculated and compared with simulation results.

''SensArray'' voltage sensor analysis in an inductively coupled plasma

International Nuclear Information System (INIS)

Titus, M. J.; Hsu, C. C.; Graves, D. B.

2010-01-01

A commercially manufactured PlasmaVolt sensor wafer was studied in an inductively coupled plasma reactor in an effort to validate sensor measurements. A pure Ar plasma at various powers (25-420 W), for a range of pressures (10-80 mT), and bias voltages (0-250 V) was utilized. A numerical sheath simulation was simultaneously developed in order to interpret experimental results. It was found that PlasmaVolt sensor measurements are proportional to the rf-current through the sheath. Under conditions such that the sheath impedance is dominantly capacitive, sensor measurements follow a scaling law derived from the inhomogeneous sheath model of Lieberman and Lichtenberg, [Principles of Plasma Discharges and Materials Processing (Wiley, New York, 2005)]. Under these conditions, sensor measurements are proportional to the square root of the plasma density at the plasma-sheath interface, the one-fourth root of the electron temperature, and the one-fourth root of the rf bias voltage. When the sheath impedance becomes increasingly resistive, the sensor measurements deviate from the scaling law and tend to be directly proportional to the plasma density. The measurements and numerical sheath simulation demonstrate the scaling behavior as a function of changing sheath impedance for various plasma conditions.

Collaborative project: research on strongly coupled plasmas. Final technical report for period July 15, 1998--July 14, 2002

International Nuclear Information System (INIS)

Golden, Kenneth I.

2002-01-01

The main research accomplishments/findings of the project were the following: (1) Publication of an in-depth review article in Physics of Plasmas on the quasilocalized charge approximation (QLCA) in strongly coupled plasma physics and its application to a variety of Coulomb systems: the model one-component plasma in three and two dimensions, binary ionic mixtures, charged particle bilayers, and laboratory dusty plasmas. (2) In the strongly coupled Coulomb liquid phase, the physical basis of the QLCA, namely, the caging of particles trapped in slowly fluctuating local potential minima, is supported by molecular dynamics simulation of the classical three-dimensional one-component plasma. (3) The QLCA theory, when applied to the analysis of the collective modes in strongly coupled charged particle bilayers, predicts the existence of a remarkable long-wavelength energy gap in the out-of-phase excitation spectrum. More recent theoretical calculations based on the three principal frequency-moment sum rules reveal that the gap persists for arbitrary coupling strengths and over the entire classical to quantum domain all the way down to zero temperature. The existence of the energy gap has now been confirmed in a molecular dynamics simulation of the charged particle bilayer. (4) New compressibility and third-frequency-moment sum rules for multilayer plasmas were formulated and applied to the analysis of the dynamical structure function of charged particle bilayers and superlattices. (5) An equivalent of the Debye-Huckel weak coupling equilibrium theory for classical charged particle bilayer and superlattice plasmas was formulated. (6) The quadratic fluctuation-dissipation theorem (QFDT) for layered classical plasmas was formulated. (7) The QFDT was applied to a powerful kinetic theory-based description of the density-density response function and long-wavelength plasma mode behavior in strongly coupled two-dimensional Coulomb fluids in the weakly degenerate quantum domain

Plasma kallikrein enhances platelet aggregation response by subthreshold doses of ADP.

Science.gov (United States)

Ottaiano, Tatiana F; Andrade, Sheila S; de Oliveira, Cleide; Silva, Mariana C C; Buri, Marcus V; Juliano, Maria A; Girão, Manoel J B C; Sampaio, Misako U; Schmaier, Alvin H; Wlodawer, Alexander; Maffei, Francisco H A; Oliva, Maria Luiza V

2017-04-01

Human plasma kallikrein (huPK) potentiates platelet responses to subthreshold doses of ADP, although huPK itself, does not induce platelet aggregation. In the present investigation, we observe that huPK pretreatment of platelets potentiates ADP-induced platelet activation by prior proteolysis of the G-protein-coupled receptor PAR-1. The potentiation of ADP-induced platelet activation by huPK is mediated by the integrin α IIb β 3 through interactions with the KGD/KGE sequence motif in huPK. Integrin α IIb β 3 is a cofactor for huPK binding to platelets to support PAR-1 hydrolysis that contributes to activation of the ADP signaling pathway. This activation pathway leads to phosphorylation of Src, AktS 473 , ERK1/2, and p38 MAPK, and to Ca 2+ release. The effect of huPK is blocked by specific antagonists of PAR-1 (SCH 19197) and α IIb β 3 (abciximab) and by synthetic peptides comprising the KGD and KGE sequence motifs of huPK. Further, recombinant plasma kallikrein inhibitor, rBbKI, also blocks this entire mechanism. These results suggest a new function for huPK. Formation of plasma kallikrein lowers the threshold for ADP-induced platelet activation. The present observations are consistent with the notion that plasma kallikrein promotes vascular disease and thrombosis in the intravascular compartment and its inhibition may ameliorate cardiovascular disease and thrombosis. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

Gluon Bremsstrahlung in Weakly-Coupled Plasmas

International Nuclear Information System (INIS)

Arnold, Peter

2009-01-01

I report on some theoretical progress concerning the calculation of gluon bremsstrahlung for very high energy particles crossing a weakly-coupled quark-gluon plasma. (i) I advertise that two of the several formalisms used to study this problem, the BDMPS-Zakharov formalism and the AMY formalism (the latter used only for infinite, uniform media), can be made equivalent when appropriately formulated. (ii) A standard technique to simplify calculations is to expand in inverse powers of logarithms ln(E/T). I give an example where such expansions are found to work well for ω/T≥10 where ω is the bremsstrahlung gluon energy. (iii) Finally, I report on perturbative calculations of q.

Radionuclide determination in environmental samples by inductively coupled plasma mass spectrometry

International Nuclear Information System (INIS)

Lariviere, Dominic; Taylor, Vivien F.; Evans, R. Douglas; Cornett, R. Jack

2006-01-01

The determination of naturally occurring and anthropogenic radionuclides in the environment by inductively coupled plasma mass spectrometry has gained recognition over the last fifteen years, relative to radiometric techniques, as the result of improvement in instrumental performance, sample introduction equipment, and sample preparation. With the increase in instrumental sensitivity, it is now possible to measure ultratrace levels (fg range) of many radioisotopes, including those with half-lives between 1 and 1000 years, without requiring very complex sample pre-concentration schemes. However, the identification and quantification of radioisotopes in environmental matrices is still hampered by a variety of analytical issues such as spectral (both atomic and molecular ions) and non-spectral (matrix effect) interferences and instrumental limitations (e.g., abundance sensitivity). The scope of this review is to highlight recent analytical progress and issues associated with the determination of radionuclides by inductively coupled plasma mass spectrometry. The impact of interferences, instrumental limitations (e.g., degree of ionization, abundance sensitivity, detection limits) and low sample-to-plasma transfer efficiency on the measurement of radionuclides by inductively coupled plasma mass spectrometry will be described. Solutions that overcome these issues will be discussed, highlighting their pros and cons and assessing their impact on the measurement of environmental radioactivity. Among the solutions proposed, mass and chemical resolution through the use of sector-field instruments and chemical reactions/collisions in a pressurized cell, respectively, will be described. Other methods, such as unique sample introduction equipment (e.g., laser ablation, electrothermal vaporisation, high efficiency nebulization) and instrumental modifications/optimizations (e.g., instrumental vacuum, radiofrequency power, guard electrode) that improve sensitivity and performance

Harmonic emission due to the nonlinear coupling of a Gaussian laser and a plasma wave

Energy Technology Data Exchange (ETDEWEB)

Pathak, R; Jain, R K [Department of Mathematics, SSL Jain College, Vidisha, MP, 464001 (India); Parashar, J [Department of Physics, Samrat Ashok Technological Institute, Vidisha, MP, 464001 (India)

2010-04-15

A high-power Gaussian laser propagating through a plasma couples with a large-amplitude plasma wave and undergoes scattering to produce harmonics. The process is sensitive to the phase matching angle between the laser and plasma wave numbers and the plasma wave frequency. For larger harmonics, the phase matching angle is high. The efficiency of the process is comparatively high at higher plasma wave frequencies.

Inductively Coupled Plasma-Induced Etch Damage of GaN p-n Junctions

International Nuclear Information System (INIS)

SHUL, RANDY J.; ZHANG, LEI; BACA, ALBERT G.; WILLISON, CHRISTI LEE; HAN, JUNG; PEARTON, S.J.; REN, F.

1999-01-01

Plasma-induced etch damage can degrade the electrical and optical performance of III-V nitride electronic and photonic devices. We have investigated the etch-induced damage of an Inductively Coupled Plasma (ICP) etch system on the electrical performance of mesa-isolated GaN pn-junction diodes. GaN p-i-n mesa diodes were formed by Cl 2 /BCl 3 /Ar ICP etching under different plasma conditions. The reverse leakage current in the mesa diodes showed a strong relationship to chamber pressure, ion energy, and plasma flux. Plasma induced damage was minimized at moderate flux conditions (≤ 500 W), pressures ≥2 mTorr, and at ion energies below approximately -275 V

Transfer coefficients in ultracold strongly coupled plasma

Science.gov (United States)

Bobrov, A. A.; Vorob'ev, V. S.; Zelener, B. V.

2018-03-01

We use both analytical and molecular dynamic methods for electron transfer coefficients in an ultracold plasma when its temperature is small and the coupling parameter characterizing the interaction of electrons and ions exceeds unity. For these conditions, we use the approach of nearest neighbor to determine the average electron (ion) diffusion coefficient and to calculate other electron transfer coefficients (viscosity and electrical and thermal conductivities). Molecular dynamics simulations produce electronic and ionic diffusion coefficients, confirming the reliability of these results. The results compare favorably with experimental and numerical data from earlier studies.

High-current electron beam coupling to hybrid waveguide and plasma modes in a dielectric Cherenkov maser with a plasma layer

International Nuclear Information System (INIS)

Shlapakovski, Anatoli S.

2002-01-01

The linear theory of a dielectric Cherenkov maser with a plasma layer has been developed. The dispersion relation has been derived for the model of infinitely thin, fully magnetized, monoenergetic hollow electron beam, in the axisymmetric case. The results of the numerical solution of the dispersion relation and the analysis of the beam coupling to hybrid waves, both hybrid waveguide and hybrid plasma modes, are presented. For the hybrid waveguide mode, spatial growth rate dependences on frequency at different plasma densities demonstrate improvement in gain for moderate densities, but strong shifting the amplification band and narrowing the bandwidth. For the hybrid plasma mode, the case of mildly relativistic, 200-250 keV beams is of interest, so that the wave phase velocity is just slightly greater than the speed of light in a dielectric medium. It has been shown that depending on beam and plasma parameters, the hybrid plasma mode can be separated from the hybrid waveguide mode, or be coupled to it through the beam resulting in strong gain increase, or exhibit a flat gain vs frequency dependence over a very broad band. The parameters, at which the -3 dB bandwidth calculated for 30 dB peak gain exceeds an octave, have been found

Matrix effects in inductively coupled plasma mass spectrometry

International Nuclear Information System (INIS)

Chen, Xiaoshan.

1995-01-01

The inductively coupled plasma is an electrodeless discharge in a gas (usually Ar) at atmospheric pressure. Radio frequency energy generated by a RF power source is inductively coupled to the plasma gas through a water cooled load coil. In ICP-MS the open-quotes Fasselclose quotes TAX quartz torch commonly used in emission is mounted horizontally. The sample aerosol is introduced into the central flow, where the gas kinetic temperature is about 5000 K. The aerosol is vaporized, atomized, excited and ionized in the plasma, and the ions are subsequently extracted through two metal apertures (sampler and skimmer) into the mass spectrometer. In ICP-MS, the matrix effects, or non-spectroscopic interferences, can be defined as the type of interferences caused by dissolved concomitant salt ions in the solution. Matrix effects can be divided into two categories: (1) signal drift due to the deposition of solids on the sampling apertures; and/or (2) signal suppression or enhancement by the presence of the dissolved salts. The first category is now reasonably understood. The dissolved salts, especially refractory oxides, tend to deposit on the cool tip of the sampling cone. The clogging of the orifices reduces the ion flow into the ICP-MS, lowers the pressure in the first stage of ICP-MS, and enhances the level of metal oxide ions. Because the extent of the clogging increases with the time, the signal drifts down. Even at the very early stage of the development of ICP-MS, matrix effects had been observed. Houk et al. found out that the ICP-MS was not tolerant to solutions containing significant amounts of dissolved solids

Discontinuity of mode transition and hysteresis in hydrogen inductively coupled plasma via a fluid model

International Nuclear Information System (INIS)

Xu Hui-Jing; Shu-Xia Zhao; Gao Fei; Zhang Yu-Ru; Li Xue-Chun; Wang You-Nian

2015-01-01

A new type of two-dimensional self-consistent fluid model that couples an equivalent circuit module is used to investigate the mode transition characteristics and hysteresis in hydrogen inductively coupled plasmas at different pressures, by varying the series capacitance of the matching box. The variations of the electron density, temperature, and the circuit electrical properties are presented. As cycling the matching capacitance, at high pressure both the discontinuity and hysteresis appear for the plasma parameters and the transferred impedances of both the inductive and capacitive discharge components, while at low pressure only the discontinuity is seen. The simulations predict that the sheath plays a determinative role on the presence of discontinuity and hysteresis at high pressure, by influencing the inductive coupling efficiency of applied power. Moreover, the values of the plasma transferred impedances at different pressures are compared, and the larger plasma inductance at low pressure due to less collision frequency, as analyzed, is the reason why the hysteresis is not seen at low pressure, even with a wider sheath. Besides, the behaviors of the coil voltage and current parameters during the mode transitions are investigated. They both increase (decrease) at the E to H (H to E) mode transition, indicating an improved (worsened) inductive power coupling efficiency. (paper)

Inductively coupled plasma and ion sources: History and state-of-the-art

International Nuclear Information System (INIS)

Hopwood, J.

1994-01-01

Over 100 years ago Hittorf first generated an electrodeless ''ring'' discharge by electromagnetic induction and began a 40 year controversy as to the true physical origin of such a discharge. Even Tesla advocated that these plasmas were merely the result of large electrostatic potential differences rather than electric fields induced by high frequency currents. Through clever experiments using crude spark gaps and leyden jars, the inductive nature of the discharge was confirmed in the late 1920's by MacKinnon, thus supporting the theories and experiments of Sir J.J. Thomson, perhaps the most staunch advocate of the induction mechanism. Today the authors routinely exploit the intense plasmas which are generated by induction. In this talk, the characteristics of inductively coupled plasma (ICP) and ion sources will be reviewed and future applications of intense plasma sources will be discussed. The inductively coupled plasma is Joule heated at moderate gas pressures, but the electromagnetic field penetration of these dense plasmas is limited by the plasma skin depth, typically a few millimeters to a few centimeters. The induction plasma is thus edge heated, a fact that constrains uniformity over large areas if helical induction coils are used. Flat, spiral coils may be used to improve uniformity by driving the plasma using a planar geometry. Issues of dimensional and frequency scaling will be discussed as they apply to large diameter sources. Ion beams extracted from ICPs are used for many applications including space propulsion, high power neutral beams, and materials processing. Broad ion beam (∼10 cm) current densities in excess of 100 mA-cm 2 at 100 keV are obtained in pulsed mode operation. Recently, however, more consumer-oriented applications of less intense ICPs are emerging

Characteristics of dust voids in a strongly coupled laboratory dusty plasma

Science.gov (United States)

Bailung, Yoshiko; Deka, T.; Boruah, A.; Sharma, S. K.; Pal, A. R.; Chutia, Joyanti; Bailung, H.

2018-05-01

A void is produced in a strongly coupled dusty plasma by inserting a cylindrical pin (˜0.1 mm diameter) into a radiofrequency discharge argon plasma. The pin is biased externally below the plasma potential to generate the dust void. The Debye sheath model is used to obtain the sheath potential profile and hence to estimate the electric field around the pin. The electric field force and the ion drag force on the dust particles are estimated and their balance accounts well for the maintenance of the size of the void. The effects of neutral density as well as dust density on the void size are studied.

Calibration of langmuir probes by a microwave method; Etalonnage des sondes de langmuir par une methode hyperfrequence

Energy Technology Data Exchange (ETDEWEB)

Consoli, T [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

Measurements of the electronic density of a plasma between 10{sup 6} and 10{sup 8} e/cm{sup 3}, made by the Langmuir probe and by resonance frequency shift of a cavity are compared. (author) [French] On compare les mesures de la densite electronique d'un plasma peu dense 10{sup 6} < ne < 10{sup 8} e/cm{sup 3}, par sonde de Langmuir et par glissement de la frequence de resonance d'une cavite contenant le plasma. (auteur)

Electrical method for the measurements of volume averaged electron density and effective coupled power to the plasma bulk

Science.gov (United States)

Henault, M.; Wattieaux, G.; Lecas, T.; Renouard, J. P.; Boufendi, L.

2016-02-01

Nanoparticles growing or injected in a low pressure cold plasma generated by a radiofrequency capacitively coupled capacitive discharge induce strong modifications in the electrical parameters of both plasma and discharge. In this paper, a non-intrusive method, based on the measurement of the plasma impedance, is used to determine the volume averaged electron density and effective coupled power to the plasma bulk. Good agreements are found when the results are compared to those given by other well-known and established methods.

Statics and thermodynamics of strongly coupled multicomponent plasmas

International Nuclear Information System (INIS)

Rosenfeld, Y.

1980-01-01

A description of strongly coupled plasmas, in which the direct correlation functions, c/sub i/j(r), are obtained by simple scaling from a universal function, is derived and found to be in full agreement with available computer simulation data, which it thus extends for arbitrary mixtures. It is thermodynamically consistent with the ''ion-sphere'' charge-averaging prediction for the enhancement factors for nuclear reaction rates, the results for which confirm the universality of the bridge functions for mixtures

Experimental benchmark of kinetic simulations of capacitively coupled plasmas in molecular gases

Science.gov (United States)

Donkó, Z.; Derzsi, A.; Korolov, I.; Hartmann, P.; Brandt, S.; Schulze, J.; Berger, B.; Koepke, M.; Bruneau, B.; Johnson, E.; Lafleur, T.; Booth, J.-P.; Gibson, A. R.; O'Connell, D.; Gans, T.

2018-01-01

We discuss the origin of uncertainties in the results of numerical simulations of low-temperature plasma sources, focusing on capacitively coupled plasmas. These sources can be operated in various gases/gas mixtures, over a wide domain of excitation frequency, voltage, and gas pressure. At low pressures, the non-equilibrium character of the charged particle transport prevails and particle-based simulations become the primary tools for their numerical description. The particle-in-cell method, complemented with Monte Carlo type description of collision processes, is a well-established approach for this purpose. Codes based on this technique have been developed by several authors/groups, and have been benchmarked with each other in some cases. Such benchmarking demonstrates the correctness of the codes, but the underlying physical model remains unvalidated. This is a key point, as this model should ideally account for all important plasma chemical reactions as well as for the plasma-surface interaction via including specific surface reaction coefficients (electron yields, sticking coefficients, etc). In order to test the models rigorously, comparison with experimental ‘benchmark data’ is necessary. Examples will be given regarding the studies of electron power absorption modes in O2, and CF4-Ar discharges, as well as on the effect of modifications of the parameters of certain elementary processes on the computed discharge characteristics in O2 capacitively coupled plasmas.

Coupling nanoliter high-performance liquid chromatography to inductively coupled plasma mass spectrometry for arsenic speciation.

Science.gov (United States)

Cheng, Heyong; Shen, Lihuan; Liu, Jinhua; Xu, Zigang; Wang, Yuanchao

2018-04-01

Nanoliter high-performance liquid chromatography shows low consumption of solvents and samples, offering one of the best choices for arsenic speciation in precious samples in combination with inuctively coupled plasma mass spectrometry. A systematic investigation on coupling nanoliter high-performance liquid chromatography to inductively coupled plasma mass spectrometry from instrument design to injected sample volume and mobile phase was performed in this study. Nanoflow mobile phase was delivered by flow splitting using a conventional high-pressure pump with reuse of mobile phase waste. Dead volume was minimized to 60 nL for the sheathless interface based on the previously developed nanonebulizer. Capillary columns for nanoliter high-performance liquid chromatography were found to be sensitive to sample loading volume. An apparent difference was also found between the mobile phases for nanoliter and conventional high-performance liquid chromatography. Baseline separation of arsenite, arsenate, monomethylarsenic, and dimethylarsenic was achieved within 11 min on a 15 cm C 18 capillary column and within 12 min on a 25 cm strong anion exchange column. Detection limits of 0.9-1.8 μg/L were obtained with precisions variable in the range of 1.6-4.2%. A good agreement between determined and certified values of a certified reference material of human urine (GBW 09115) validated its accuracy along with good recoveries (87-102%). © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

ICRF plasma production in Tore Supra: analysis of antenna coupling and plasma properties

International Nuclear Information System (INIS)

Beaumont, B.; Becoulet, A.; Lyssoivan, A.

1999-01-01

A study of RF plasma production frequency range ω. 2ω ci has been undertaken on Tore Supra taking into account antenna coupling predictions of theory and the TEXTOR-94 database. Two scenarios for RF discharges have been tested (fixed frequency of the RF generator): operation with pure toroidal magnetic field, at standard and lower B T and operation in the magnetic configuration with a small vertical (B V ) field superimposed on B T (B V T ). (authors)

Protease-Activated Receptor 4 (PAR4): A Promising Target for Antiplatelet Therapy.

Science.gov (United States)

Rwibasira Rudinga, Gamariel; Khan, Ghulam Jilany; Kong, Yi

2018-02-14

Cardiovascular diseases (CVDs) are currently among the leading causes of death worldwide. Platelet aggregation is a key cellular component of arterial thrombi and major cause of CVDs. Protease-activated receptors (PARs), including PAR1, PAR2, PAR3 and PAR4, fall within a subfamily of seven-transmembrane G-protein-coupled receptors (GPCR). Human platelets express PAR1 and PAR4, which contribute to the signaling transduction processes. In association with CVDs, PAR4 not only contributes to platelet activation but also is a modulator of cellular responses that serve as hallmarks of inflammation. Although several antiplatelet drugs are available on the market, they have many side effects that limit their use. Emerging evidence shows that PAR4 targeting is a safer strategy for preventing thrombosis and consequently may improve the overall cardiac safety profile. Our present review summarizes the PAR4 structural characteristics, activation mechanism, role in the pathophysiology of diseases and understanding the association of PAR4 targeting for improved cardiac protection. Conclusively, this review highlights the importance of PAR4 antagonists and its potential utility in different CVDs.

Diagnostic studies of ion beam formation in inductively coupled plasma

Energy Technology Data Exchange (ETDEWEB)

Jacobs, Jenee L. [Iowa State Univ., Ames, IA (United States)

2015-01-01

This dissertation describes a variety of studies focused on the plasma and the ion beam in inductively coupled plasma mass spectrometry (ICP-MS). The ability to use ICP-MS for measurements of trace elements in samples requires the analytes to be efficiently ionized. Updated ionization efficiency tables are discussed for ionization temperatures of 6500 K and 7000 K with an electron density of 1 x 10¹⁵ cm^-3. These values are reflective of the current operating parameters of ICP-MS instruments. Calculations are also discussed for doubly charged (M²⁺) ion formation, neutral metal oxide (MO) ionization, and metal oxide (MO⁺) ion dissociation for similar plasma temperature values. Ionization efficiency results for neutral MO molecules in the ICP have not been reported previously.

On the possibility of the multiple inductively coupled plasma and helicon plasma sources for large-area processes

Energy Technology Data Exchange (ETDEWEB)

Lee, Jin-Won; Lee, Yun-Seong, E-mail: leeeeys@kaist.ac.kr; Chang, Hong-Young [Low-temperature Plasma Laboratory, Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701 (Korea, Republic of); An, Sang-Hyuk [Agency of Defense Development, Yuseong-gu, Daejeon 305-151 (Korea, Republic of)

2014-08-15

In this study, we attempted to determine the possibility of multiple inductively coupled plasma (ICP) and helicon plasma sources for large-area processes. Experiments were performed with the one and two coils to measure plasma and electrical parameters, and a circuit simulation was performed to measure the current at each coil in the 2-coil experiment. Based on the result, we could determine the possibility of multiple ICP sources due to a direct change of impedance due to current and saturation of impedance due to the skin-depth effect. However, a helicon plasma source is difficult to adapt to the multiple sources due to the consistent change of real impedance due to mode transition and the low uniformity of the B-field confinement. As a result, it is expected that ICP can be adapted to multiple sources for large-area processes.

Effect of antenna size on electron kinetics in inductively coupled plasmas

Energy Technology Data Exchange (ETDEWEB)

Lee, Hyo-Chang; Chung, Chin-Wook [Department of Electrical Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of)

2013-10-15

Spatially resolved measurements of electron energy distribution functions (EEDFs) are investigated in inductively coupled plasmas with two planar antenna coils. When the plasma is sustained by the antenna with a diameter of 18 cm, the nonlocal kinetics is preserved in the argon gas pressure range from 2 mTorr to 20 mTorr. However, electron kinetics transit from nonlocal kinetics to local kinetics in discharge sustained by the antenna coil with diameter 34 cm. The results suggest that antenna size as well as chamber length are important parameters for the transition of the electron kinetics. Spatial variations of plasma potential, effective electron temperature, and EEDF in terms of total electron energy scale are also presented.

Analytical solution for a coaxial plasma gun: Weak coupling limit

International Nuclear Information System (INIS)

Dietz, D.

1987-01-01

The analytical solution of the system of coupled ODE's which describes the time evolution of an ideal (i.e., zero resistance) coaxial plasma gun operating in the snowplow mode is obtained in the weak coupling limit, i.e, when the gun is fully influenced by the driving (RLC) circuit in which it resides but the circuit is negligibly influenced by the gun. Criteria for the validity of this limit are derived and numerical examples are presented. Although others have obtained approximate, asymptotic and numerical solutions of the equations, the present analytical results seem not to have appeared previously in the literature

The determination of transition probabilities with an inductively-coupled plasma discharge

International Nuclear Information System (INIS)

Nieuwoudt, G.

1984-03-01

The 27 MHz inductively-coupled plasma discharge (ICP) is used for the determination of relative transition probabilities of the 451, 459 and 470 nm argon spectral lines. The temperature of the argon plasma is determined with hydrogen as thermometric specie, because of the accurate transition probabilities ( approximately 1% uncertainty) there of. The relative transition probabilities of the specific argon spectral lines were determined by substitution of the measured spectral radiances thereof, together with the hydrogen temperature, in the two-line equation of temperature measurement

Theoretical investigation of phase-controlled bias effect in capacitively coupled plasma discharges

International Nuclear Information System (INIS)

Kwon, Deuk-Chul; Yoon, Jung-Sik

2011-01-01

We theoretically investigated the effect of phase difference between powered electrodes in capacitively coupled plasma (CCP) discharges. Previous experimental result has shown that the plasma potential could be controlled by using a phase-shift controller in CCP discharges. In this work, based on the previously developed radio frequency sheath models, we developed a circuit model to self-consistently determine the bias voltage from the plasma parameters. Results show that the present theoretical model explains the experimental results quite well and there is an optimum value of the phase difference for which the V dc /V pp ratio becomes a minimum.

Energy Conservation Tests of a Coupled Kinetic-kinetic Plasma-neutral Transport Code

Energy Technology Data Exchange (ETDEWEB)

Stotler, D. P.; Chang, C. S.; Ku, S. H.; Lang, J.; Park, G.

2012-08-29

A Monte Carlo neutral transport routine, based on DEGAS2, has been coupled to the guiding center ion-electron-neutral neoclassical PIC code XGC0 to provide a realistic treatment of neutral atoms and molecules in the tokamak edge plasma. The DEGAS2 routine allows detailed atomic physics and plasma-material interaction processes to be incorporated into these simulations. The spatial pro le of the neutral particle source used in the DEGAS2 routine is determined from the uxes of XGC0 ions to the material surfaces. The kinetic-kinetic plasma-neutral transport capability is demonstrated with example pedestal fueling simulations.

State-space modeling of the radio frequency inductively-coupled plasma generator

International Nuclear Information System (INIS)

Dewangan, Rakesh Kumar; Punjabi, Sangeeta B; Mangalvedekar, H A; Lande, B K; Joshi, N K; Barve, D N

2010-01-01

Computational fluid dynamics models of RF-ICP are useful in understanding the basic transport phenomenon in an ICP torch under a wide variety of operating conditions. However, these models lack the ability to evaluate the effects of the plasma condition on the RF generator. In this paper, simulation of an induction plasma generator has been done using state space modelling by considering inductively coupled plasma as a part of RF network .The time dependent response of the RF-ICP generator circuit to given input excitation has been computed by extracting the circuit's state-space variables and their constraint matrices. MATLAB 7.1 software has been used to solve the state equations. The values of RF coil current, frequency and plasma power has been measured experimentally also at different plate bias voltage. The simulated model is able to predict RF coil current, frequency, plasma power, overall efficiency of the generator. The simulated and measured values are in agreement with each other. This model can prove useful as a design tool for the Induction plasma generator.

HEMOFILTRATION AND COUPLED PLASMA FILTRATION ADSORPTION IMPACT ON TACROLIMUS BLOOD CONCENTRATION IN RENAL TRANSPLANT RECIPIENTS

Directory of Open Access Journals (Sweden)

A.V. Vatazin

2014-01-01

Full Text Available Aim. To study the effect of hemofi ltration and coupled plasma fi ltration adsorption on tacrolimus blood concentration in renal transplant recipients.Methods and results. The study included 8 renal transplant recipients. In these patients immediately after the operation was performed the coupled plasma fi ltration adsorption with hemofiltration using a cartridge Mediasorb to reduce the severity of reperfusion injury. We have found that during this extracorporeal blood correction procedure there was statistically not signifi cant decrease of tacrolimus blood concentration. However, concentration of tacrolimus remained in the therapeutic range even after the procedure and it was not signifi cantly different from the control point С0.Conclusion. Coupled plasma fi ltration adsorption is safe in renal transplant recipients and has no signifi cant impact on tacrolimus blood concentration. However, the downward trend in the concentration of tacrolimus in the course of these procedures, especially in continuous or semicontinuous mode, as well as in patients with low hematocrit and hypoalbuminemia, requires individual monitoring.

Multi-chord fiber-coupled interferometry of supersonic plasma jets (invited)

International Nuclear Information System (INIS)

Merritt, Elizabeth C.; Lynn, Alan G.; Gilmore, Mark A.; Thoma, Carsten; Loverich, John; Hsu, Scott C.

2012-01-01

A multi-chord fiber-coupled interferometer is being used to make time-resolved density measurements of supersonic argon plasma jets on the Plasma Liner Experiment. The long coherence length of the laser (>10 m) allows signal and reference path lengths to be mismatched by many meters without signal degradation, making for a greatly simplified optical layout. Measured interferometry phase shifts are consistent with a partially ionized plasma in which both positive and negative phase shift values are observed depending on the ionization fraction. In this case, both free electrons and bound electrons in ions and neutral atoms contribute to the index of refraction. This paper illustrates how the interferometry data, aided by numerical modeling, are used to derive total jet density, jet propagation velocity (∼15–50 km/s), jet length (∼20–100 cm), and 3D expansion.

Inductively coupled hydrogen plasma processing of AZO thin films for heterojunction solar cell applications

International Nuclear Information System (INIS)

Zhou, H.P.; Xu, S.; Zhao, Z.; Xiang, Y.

2014-01-01

Highlights: • A high-density plasma reactor of inductively coupled plasma source is used in this work. • The conductivity and transmittance can be enhanced simultaneously in the hydrogen process. • The formation of additional donors and passivation due to the hydrogen plasma processing. • The photovoltaic improvement due to the improved AZO layer and hetero-interface quality in the solar cells. - Abstract: Al-doped ZnO (AZO) thin films deposited by means of RF magnetron sputtering were processed in a low frequency inductively coupled plasma of H 2 , aiming at heterojunction (HJ) solar cell applications. A variety of characterization results show that the hydrogen plasma processing exerts a significant influence on the microstructures, electrical and optical properties of the AZO films. The incorporation of hydrogen under the optimum treatment simultaneously promoted the transmittance and conductivity due to the hydrogen associated passivation effect on the native defects and the formation of shallow donors in the films, respectively. A p-type c-Si based HJ solar cell with a front AZO contact was also treated in as-generated non-equilibrium hydrogen plasma and the photovoltaic performance of the solar cell was prominently improved. The underlying mechanism was discussed in terms of the beneficial impacts of high-density hydrogen plasma on the properties of AZO itself and the hetero-interfaces involved in the HJ structure (interface defect and energy band configuration)

Influence of driving frequency on oxygen atom density in O2 radio frequency capacitively coupled plasma

International Nuclear Information System (INIS)

Kitajima, Takeshi; Noro, Kouichi; Nakano, Toshiki; Makabe, Toshiaki

2004-01-01

The influence of the driving frequency on the absolute oxygen atom density in an O 2 radio frequency (RF) capacitively coupled plasma (CCP) was investigated using vacuum ultraviolet absorption spectroscopy with pulse modulation of the main plasma. A low-power operation of a compact inductively coupled plasma light source was enabled to avoid the significant measurement errors caused by self-absorption in the light source. The pulse modulation of the main plasma enabled accurate absorption measurement for high plasma density conditions by eliminating background signals due to light emission from the main plasma. As for the effects of the driving frequency, the effect of VHF (100 MHz) drive on oxygen atom production was small because of the modest increase in plasma density of electronegative O 2 in contrast to the significant increase in electron density previously observed for electropositive Ar. The recombination coefficient of oxygen atoms on the electrode surface was obtained from a decay rate in the afterglow by comparison with a diffusion model, and it showed agreement with previously reported values for several electrode materials

Protease-Activated Receptor 4 (PAR4: A Promising Target for Antiplatelet Therapy

Directory of Open Access Journals (Sweden)

Gamariel Rwibasira Rudinga

2018-02-01

Full Text Available Cardiovascular diseases (CVDs are currently among the leading causes of death worldwide. Platelet aggregation is a key cellular component of arterial thrombi and major cause of CVDs. Protease-activated receptors (PARs, including PAR1, PAR2, PAR3 and PAR4, fall within a subfamily of seven-transmembrane G-protein-coupled receptors (GPCR. Human platelets express PAR1 and PAR4, which contribute to the signaling transduction processes. In association with CVDs, PAR4 not only contributes to platelet activation but also is a modulator of cellular responses that serve as hallmarks of inflammation. Although several antiplatelet drugs are available on the market, they have many side effects that limit their use. Emerging evidence shows that PAR4 targeting is a safer strategy for preventing thrombosis and consequently may improve the overall cardiac safety profile. Our present review summarizes the PAR4 structural characteristics, activation mechanism, role in the pathophysiology of diseases and understanding the association of PAR4 targeting for improved cardiac protection. Conclusively, this review highlights the importance of PAR4 antagonists and its potential utility in different CVDs.

Online Coupling of Flow-Field Flow Fractionation and Single Particle Inductively Coupled Plasma-Mass Spectrometry: Characterization of Nanoparticle Surface Coating Thickness and Aggregation State

Science.gov (United States)

Surface coating thickness and aggregation state have strong influence on the environmental fate, transport, and toxicity of engineered nanomaterials. In this study, flow-field flow fractionation coupled on-line with single particle inductively coupled plasma-mass spectrometry i...

Electromagneto-mechanical coupling analysis of a test module in J-TEXT Tokamak during plasma disruption

Energy Technology Data Exchange (ETDEWEB)

Dong, Haijie; Yuan, Zhensheng; Yuan, Hongwei; Pei, Cuixiang [State Key Laboratory for Strength and Vibration of Mechanical Structures, Shanxi Engineering Research Center for NDT and Structural Integrity Evaluation Xi’an Jiaotong University, Xi’an 710049 (China); Chen, Zhenmao, E-mail: chenzm@mail.xjtu.edu.cn [State Key Laboratory for Strength and Vibration of Mechanical Structures, Shanxi Engineering Research Center for NDT and Structural Integrity Evaluation Xi’an Jiaotong University, Xi’an 710049 (China); Yang, Jinhong; Wang, Weihua [Institute of Applied Physics of AOA, Hefei 230031 (China)

2016-11-01

In this paper, the dynamic response during plasma disruption of a test blanket module in vacuum vessel (VV) of the Joint TEXT (J-TEXT), which is an experimental Tokamak device with iron core, was simulated by applying a program developed by authors on the ANSYS platform using its parametric design language (APDL). The moving coordinate method as well as the load transfer and sequential coupling strategy were adopted to cope with the electromagneto-mechanical coupling effect. To establish the numerical model, the influence of the iron core on the eddy current and electromagnetic (EM) force during disruption was numerically investigated at first and the influence was found not significant. Together with the geometrical features of the J-TEXT Tokamak structure, 180° sector models without magnetic core were finally established for the EM field and the structural response simulations. To obtain the source plasma current, the plasma current evolution during disruption was simulated by using the Tokamak Simulation Code (TSC). With the numerical models and the source plasma current, the dynamic response of both the VV structure and the test module were calculated. The numerical results show that the maximum stress of the test module is in safe range, and the magnetic damping effect can weaken vibration of the test module. In addition, simulation without considering the coupling effect was carried out, which shows that the influence of coupling effect is not significant for the peak stress of the J-TEXT disruption problem.

Trace determination of Pu by LIF in an inductively coupled plasma

International Nuclear Information System (INIS)

Mauchien, P.; Briand, A.; Moulin, C.

1989-01-01

Inductively Coupled Plasma/Emission Spectrometry (ICP/ES) technique is largely used in the nuclear industry as an elementary analytical technique. Nevertheless, when the sample to analyse presents elements with a lot of emission spectral lines, spectral interferences lead to limited sensitivity. This is the case for Pu determination in presence of large U concentration. In pure aqueous solution, the limit of detection (LOD) for Pu is 10 μg/1. In presence of U, the LOD is determined by a ratio U/Pu = 1000. Pulsed Laser Induced Fluorescence (LIF) spectrometry is known to be a very selective technique when associated with an Inductively Coupled Plasma source. The absolute sensitivity is better by 2 or 3 orders of magnitude; its principle is based on selective excitation of the ionic species in the plasma followed by fluorescence radiation detection of these species; this radiation being practically free from spectral interferences, it is possible to improve the relative LOD. In this presentation, experimental results performed at Cogema/Marcoule laboratory are presented. After the experimental set-up description, first results of LIF are shown: - very good selectivity is effectively obtained, - a series of analytical results obtained with excitation scanning from the visible to the U.V. show that sensitivity of LIF technique is strictly related to the spectroscopic scheme

Fluid model of inductively coupled plasma etcher based on COMSOL

International Nuclear Information System (INIS)

Cheng Jia; Ji Linhong; Zhu Yu; Shi Yixiang

2010-01-01

Fluid dynamic models are generally appropriate for the investigation of inductively coupled plasmas. A commercial ICP etcher filled with argon plasma is simulated in this study. The simulation is based on a multiphysical software, COMSOL(TM), which is a partial differential equation solver. Just as with other plasma fluid models, there are drift-diffusion approximations for ions, the quasi-neutrality assumption for electrons movements, reduced Maxwell equations for electromagnetic fields, electron energy equations for electron temperatures and the Navier-Stokes equation for neutral background gas. The two-dimensional distribution of plasma parameters are shown at 200 W of power and 1.33 Pa (10 mTorr) of pressure. Then the profile comparison of the electron number density and temperature with respect to power is illustrated. Finally we believe that there might be some disagreement between the predicted values and the real ones, and the reasons for this difference would be the Maxwellian eedf assumption and the lack of the cross sections of collisions and the reaction rates. (semiconductor physics)

Similarity analysis for the high-pressure inductively coupled plasma source

International Nuclear Information System (INIS)

Vanden-Abeele, D; Degrez, G

2004-01-01

It is well known that the optimal operating parameters of an inductively coupled plasma (ICP) torch strongly depend upon its dimensions. To understand this relationship better, we derive a dimensionless form of the equations governing the behaviour of high-pressure ICPs. The requirement of similarity then naturally leads to expressions for the operating parameters as a function of the plasma radius. In addition to the well-known scaling law for frequency, surprising results appear for the dependence of the mass flow rate, dissipated power and operating pressure upon the plasma radius. While the obtained laws do not appear to be in good agreement with empirical results in the literature, their correctness is supported by detailed numerical calculations of ICP sources of varying diameters. The approximations of local thermodynamic equilibrium and negligible radiative losses restrict the validity of our results and can be responsible for the disagreement with empirical data. The derived scaling laws are useful for the design of new plasma torches and may provide explanations for the unsteadiness observed in certain existing ICP sources

Joule Heating of Plasma in the Toroidal Tokamak-3 Device; Chauffage du Plasma par Effet Joule, dans l'Installation Torique; Dzhoulev nagrev plazmy na toroidal'noj ustanovke Tokamak-3; Calentamiento de un Plasma por Efeto Joule en la Instalacion Toroidal Tokamak

Energy Technology Data Exchange (ETDEWEB)

Arcimovich, L. A.; Afrosimov, V. V.; Gladkovskij, I. P.; Mirnov, S. V.; Petrov, M. P.; Strelkov, V. S. [Institut Atomnoj Ehnergii, Im. I.V. Kurchatova, Moskva, SSSR (Russian Federation)

1966-04-15

function increases during the process and reaches 100 to 200 eV. Spectroscopic measurements of the electron temperature give values close to the computed values. The measured energy distributions of the fast neutral-atom flux fit in well with the assumption that the ion distribution of the plasma resembles a Maxwellian distribution of about 100 eV. A significant departure of this distribution from a Maxwellian is observed in the unstable discharge at the same moments as the characteristic plasma column instabilities. In addition, a perceptible difference is observed in the flux of neutrals from the' ''upper'' and the ''lower'' portions of the column, which can be explained by ion drift fluxes inside the column that have large transverse velocities. (author) [French] Dans l'installation Tokamak-3, on cree un plasma d'hydrogene et on le chauffe par un courant electrique annulaire de 40 a 60 kA. Le temps de passage du courant est de 20 a 30 ms. Une grade partie des experiences a ete faite avec un champ magnetique longitudinal stabilisateur de 25 kOe. La composante transversale du champ magnetique parasite etait compensee au moyen de courants passant dans des spires de correction speciales. Dans ces conditions il ne s'est produit aucun deplacement perceptible du centre de la colonne a partir du plan equatorial du tore, au cours de la decharge, et les auteurs ont observe une derive de la colonne de plasma 'vers l'exterieur' (accroissement du grand rayon de la spire). Ce mouvement peut etre cause par une variation du rayon de la colonne de courant, par le chauffage du plasma ou par l'amortissement des courants de Foucault dans la chemise conductrice. Dans ces conditions, ies auteurs ont reussi a obtenir dans l'installation Tokamak-3 une colonne de plasma, stable du point de vue macroscopique; cependant la temperature du plasma etait inferieure a la temperature prevue en cas d'absence de pertes anormales d'energie. Les processus qui apparaissent dans le cas d'une interaction

Ion deposition by inductively coupled plasma mass spectrometry

International Nuclear Information System (INIS)

Hu, K.; Houk, R.S.

1996-01-01

An atmospheric pressure inductively coupled plasma (ICP) is used with a quadrupole mass spectrometer (MS) for ion deposition. The deposited element is introduced as a nebulized aqueous solution. Modifications to the ICP-MS device allow generation and deposition of a mass-resolved beam of 165 Ho + at 5x10 12 ions s -1 . The ICP is a universal, multielement ion source that can potentially be used for applications such as deposition of mixtures of widely varying stoichiometry or of alternating layers of different elements. copyright 1996 American Vacuum Society

Thermodynamics of strongly coupled repulsive Yukawa particles in ambient neutralizing plasma: Thermodynamic instability and the possibility of observation in fine particle plasmas

International Nuclear Information System (INIS)

Totsuji, Hiroo

2008-01-01

The thermodynamics is analyzed for a system composed of particles with hard cores, interacting via the repulsive Yukawa potential (Yukawa particulates), and neutralizing ambient (background) plasma. An approximate equation of state is given with proper account of the contribution of ambient plasma and it is shown that there exists a possibility for the total isothermal compressibility of Yukawa particulates and ambient plasma to diverge when the coupling between Yukawa particulates is sufficiently strong. In this case, the system undergoes a transition into separated phases with different densities and we have a critical point for this phase separation. Examples of approximate phase diagrams related to this transition are given. It is emphasized that the critical point can be in the solid phase and we have the possibility to observe a solid-solid phase separation. The applicability of these results to fine particle plasmas is investigated. It is shown that, though the values of the characteristic parameters are semiquantitative due to the effects not described by this model, these phenomena are expected to be observed in fine particle plasmas, when approximately isotropic bulk systems are realized with a very strong coupling between fine particles.

Thermodynamics of strongly coupled repulsive Yukawa particles in ambient neutralizing plasma: Thermodynamic instability and the possibility of observation in fine particle plasmas

Science.gov (United States)

Totsuji, Hiroo

2008-07-01

The thermodynamics is analyzed for a system composed of particles with hard cores, interacting via the repulsive Yukawa potential (Yukawa particulates), and neutralizing ambient (background) plasma. An approximate equation of state is given with proper account of the contribution of ambient plasma and it is shown that there exists a possibility for the total isothermal compressibility of Yukawa particulates and ambient plasma to diverge when the coupling between Yukawa particulates is sufficiently strong. In this case, the system undergoes a transition into separated phases with different densities and we have a critical point for this phase separation. Examples of approximate phase diagrams related to this transition are given. It is emphasized that the critical point can be in the solid phase and we have the possibility to observe a solid-solid phase separation. The applicability of these results to fine particle plasmas is investigated. It is shown that, though the values of the characteristic parameters are semiquantitative due to the effects not described by this model, these phenomena are expected to be observed in fine particle plasmas, when approximately isotropic bulk systems are realized with a very strong coupling between fine particles.

Nonlinear electromagnetic fields in 0.5 MHz inductively coupled plasmas

DEFF Research Database (Denmark)

Ostrikov, K.N.; Tsakadze, E.L.; Xu, S.

2003-01-01

Radial profiles of magnetic fields in the electrostatic (E) and electromagnetic (H) modes of low-frequency (similar to500 kHz) inductively coupled plasmas have been measured using miniature magnetic probes. In the low-power (similar to170 W) E-mode, the magnetic field pattern is purely linear......, with the fundamental frequency harmonics only. After transition to higher-power (similar to1130 W) H-mode, the second-harmonic nonlinear azimuthal magnetic field B-phi(2omega) that is in 4-6 times larger than the fundamental frequency component B-phi(omega), has been observed. A simplified plasma fluid model...... explaining the generation of the second harmonics of the azimuthal magnetic field in the plasma source is proposed. The nonlinear second harmonic poloidal (r-z) rf current generating the azimuthal magnetic field B-phi(2omega) is attributed to nonlinear interactions between the fundamental frequency radial...

Difference in chemical reactions in bulk plasma and sheath regions during surface modification of graphene oxide film using capacitively coupled NH{sub 3} plasma

Energy Technology Data Exchange (ETDEWEB)

Lee, Sung-Youp; Kim, Chan; Kim, Hong Tak, E-mail: zam89blue@gmail.com [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of)

2015-09-14

Reduced graphene oxide (r-GO) films were obtained from capacitively coupled NH{sub 3} plasma treatment of spin-coated graphene oxide (GO) films at room temperature. Variations were evaluated according to the two plasma treatment regions: the bulk plasma region (R{sub bulk}) and the sheath region (R{sub sheath}). Reduction and nitridation of the GO films began as soon as the NH{sub 3} plasma was exposed to both regions. However, with the increase in treatment time, the reduction and nitridation reactions differed in each region. In the R{sub bulk}, NH{sub 3} plasma ions reacted chemically with oxygen functional groups on the GO films, which was highly effective for reduction and nitridation. While in the R{sub sheath}, physical reactions by ion bombardment were dominant because plasma ions were accelerated by the strong electrical field. The accelerated plasma ions reacted not only with the oxygen functional groups but also with the broken carbon chains, which caused the removal of the GO films by the formation of hydrocarbon gas species. These results showed that reduction and nitridation in the R{sub bulk} using capacitively coupled NH{sub 3} plasma were very effective for modifying the properties of r-GO films for application as transparent conductive films.

A study on improvement of discharge characteristic by using a transformer in a capacitively coupled plasma

Energy Technology Data Exchange (ETDEWEB)

Kim, Young-Cheol [Department of Nanoscale Semiconductor Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Kim, Hyun-Jun; Lee, Hyo-Chang; Chung, Chin-Wook, E-mail: joykang@hanyang.ac.kr [Department of Electrical Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 133-791 (Korea, Republic of)

2015-12-15

In a plasma discharge system, the power loss at powered line, matching network, and other transmission line can affect the discharge characteristics such as the power transfer efficiency, voltage and current at powered electrode, and plasma density. In this paper, we propose a method to reduce power loss by using a step down transformer mounted between the matching network and the powered electrode in a capacitively coupled argon plasma. This step down transformer decreases the power loss by reducing the current flowing through the matching network and transmission line. As a result, the power transfer efficiency was increased about 5%–10% by using a step down transformer. However, the plasma density was dramatically increased compared to no transformer. This can be understood by the increase in ohmic heating and the decrease in dc-self bias. By simply mounting a transformer, improvement of discharge efficiency can be achieved in capacitively coupled plasmas.

Chemical modeling of a high-density inductively-coupled plasma reactor containing silane

NARCIS (Netherlands)

Kovalgin, Alexeij Y.; Boogaard, A.; Brunets, I.; Holleman, J.; Schmitz, Jurriaan

We carried out the modeling of chemical reactions in a silane-containing remote Inductively Coupled Plasma Enhanced Chemical Vapor Deposition (ICPECVD) system, intended for deposition of silicon, silicon oxide, and silicon nitride layers. The required electron densities and Electron Energy

Protease-activated receptor (PAR2, but not PAR1, is involved in collateral formation and anti-inflammatory monocyte polarization in a mouse hind limb ischemia model.

Directory of Open Access Journals (Sweden)

Lisa G van den Hengel

Full Text Available AIMS: In collateral development (i.e. arteriogenesis, mononuclear cells are important and exist as a heterogeneous population consisting of pro-inflammatory and anti-inflammatory/repair-associated cells. Protease-activated receptor (PAR1 and PAR2 are G-protein-coupled receptors that are both expressed by mononuclear cells and are involved in pro-inflammatory reactions, while PAR2 also plays a role in repair-associated responses. Here, we investigated the physiological role of PAR1 and PAR2 in arteriogenesis in a murine hind limb ischemia model. METHODS AND RESULTS: PAR1-deficient (PAR1-/-, PAR2-deficient (PAR2-/- and wild-type (WT mice underwent femoral artery ligation. Laser Doppler measurements revealed reduced post-ischemic blood flow recovery in PAR2-/- hind limbs when compared to WT, while PAR1-/- mice were not affected. Upon ischemia, reduced numbers of smooth muscle actin (SMA-positive collaterals and CD31-positive capillaries were found in PAR2-/- mice when compared to WT mice, whereas these parameters in PAR1-/- mice did not differ from WT mice. The pool of circulating repair-associated (Ly6C-low monocytes and the number of repair-associated (CD206-positive macrophages surrounding collaterals in the hind limbs were increased in WT and PAR1-/- mice, but unaffected in PAR2-/- mice. The number of repair-associated macrophages in PAR2-/- hind limbs correlated with CD11b- and CD115-expression on the circulating monocytes in these animals, suggesting that monocyte extravasation and M-CSF-dependent differentiation into repair-associated cells are hampered. CONCLUSION: PAR2, but not PAR1, is involved in arteriogenesis and promotes the repair-associated response in ischemic tissues. Therefore, PAR2 potentially forms a new pro-arteriogenic target in coronary artery disease (CAD patients.

Global (volume-averaged) model of inductively coupled chlorine plasma : influence of Cl wall recombination and external heating on continuous and pulse-modulated plasmas

NARCIS (Netherlands)

Kemaneci, E.H.; Carbone, E.A.D.; Booth, J.P.; Graef, W.A.A.D.; Dijk, van J.; Kroesen, G.M.W.

An inductively coupled radio-frequency plasma in chlorine is investigated via a global (volume-averaged) model, both in continuous and square wave modulated power input modes. After the power is switched off (in a pulsed mode) an ion–ion plasma appears. In order to model this phenomenon, a novel

New approach to the determination phosphorothioate oligonucleotides by ultra high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry.

Science.gov (United States)

Studzińska, Sylwia; Mounicou, Sandra; Szpunar, Joanna; Łobiński, Ryszard; Buszewski, Bogusław

2015-01-15

This text presents a novel method for the separation and detection of phosphorothioate oligonucleotides with the use of ion pair ultra high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry The research showed that hexafluoroisopropanol/triethylamine based mobile phases may be successfully used when liquid chromatography is coupled with such elemental detection. However, the concentration of both HFIP and TEA influences the final result. The lower concentration of HFIP, the lower the background in ICP-MS and the greater the sensitivity. The method applied for the analysis of serum samples was based on high resolution inductively coupled plasma mass spectrometry. Utilization of this method allows determination of fifty times lower quantity of phosphorothioate oligonucleotides than in the case of quadrupole mass analyzer. Monitoring of (31)P may be used to quantify these compounds at the level of 80 μg L(-1), while simultaneous determination of sulfur is very useful for qualitative analysis. Moreover, the results presented in this paper demonstrate the practical applicability of coupling LC with ICP-MS in determining phosphorothioate oligonucleotides and their metabolites in serum within 7 min with a very good sensitivity. The method was linear in the concentration range between 0.2 and 3 mg L(-1). The limit of detection was in the range of 0.07 and 0.13 mg L(-1). Accuracy varied with concentration, but was in the range of 3%. Copyright © 2014 Elsevier B.V. All rights reserved.

Computer simulations of an oxygen inductively coupled plasma used for plasma-assisted atomic layer deposition

International Nuclear Information System (INIS)

Tinck, S; Bogaerts, A

2011-01-01

In this paper, an O 2 inductively coupled plasma used for plasma enhanced atomic layer deposition of Al 2 O 3 thin films is investigated by means of modeling. This work intends to provide more information about basic plasma properties such as species densities and species fluxes to the substrate as a function of power and pressure, which might be hard to measure experimentally. For this purpose, a hybrid model developed by Kushner et al is applied to calculate the plasma characteristics in the reactor volume for different chamber pressures ranging from 1 to 10 mTorr and different coil powers ranging from 50 to 500 W. Density profiles of the various oxygen containing plasma species are reported as well as fluxes to the substrate under various operating conditions. Furthermore, different orientations of the substrate, which can be placed vertically or horizontally in the reactor, are taken into account. In addition, special attention is paid to the recombination process of atomic oxygen on the different reactor walls under the stated operating conditions. From this work it can be concluded that the plasma properties change significantly in different locations of the reactor. The plasma density near the cylindrical coil is high, while it is almost negligible in the neighborhood of the substrate. Ion and excited species fluxes to the substrate are found to be very low and negligible. Finally, the orientation of the substrate has a minor effect on the flux of O 2 , while it has a significant effect on the flux of O. In the horizontal configuration, the flux of atomic oxygen can be up to one order of magnitude lower than in the vertical configuration.

PET imaging of urokinase-type plasminogen activator receptor (uPAR) in prostate cancer

DEFF Research Database (Denmark)

Skovgaard, Dorthe; Persson, Morten; Kjaer, Andreas

2016-01-01

Overexpression of urokinase-type plasminogen activator receptors (uPAR) represents an important biomarker for aggressiveness in most common malignant diseases, including prostate cancer (PC). Accordingly, uPAR expression either assessed directly in malignant PC tissue or assessed directly in plasma...... and prognostic imaging method. In this review, we will focus on the recent development of uPAR PET and the relevance within prostate cancer imaging. Novel antibody and small-molecule radiotracers-targeting uPAR, including a series of uPAR-targeting PET ligands, based on the high affinity peptide ligand AE105......, have been synthesized and tested in vitro and in vivo in preclinical murine xenograft models and, recently, in a first-ever clinical uPAR PET study in cancer patients, including patients with PC. In this phase I study, a high and specific uptake of the tracer 64Cu-DOTA-AE105 was found in both primary...

Effect of electromagnetic waves and higher harmonics in capacitively coupled plasma phenomena

International Nuclear Information System (INIS)

Upadhyay, R R; Sawada, I; Ventzek, P L G; Raja, L L

2013-01-01

High-resolution self-consistent numerical simulation of electromagnetic wave phenomena in an axisymmetric capacitively coupled plasma reactor is reported. A prominent centre-peaked plasma density profile is observed for driving frequencies of 60 MHz and is consistent with observations in the literature and accompanying experimental studies. A power spectrum of the simulated wave electric field reveals the presence of well-resolved high frequency harmonic content up to the 20th harmonic of the excitation frequency; an observation that has also been reported in experiments. Importantly, the simulation results reveal that the occurrence of higher harmonics is strongly correlated with the occurrence of a centre-peaked plasma density profile. (fast track communication)

Inductively coupled plasma source mass spectrometry

International Nuclear Information System (INIS)

Price Russ, G. III

1993-01-01

Inductively coupled plasma source mass spectrometry (ICP-MS) is a relatively new (5 y commercial availability) technique for simultaneously determining the concentration and isotopic composition of a large number of elements at trace levels. The principle advantages of ICP-MS are the ability to measure essentially all the metallic elements at concentrations as low as 1 part in 10 12 by weight, to analyse aqueous samples directly, to determine the isotopic composition of essentially all the metallic elements, and to analyse samples rapidly (minutes). The history of the development of ICP-MS and discussions of a variety of applications have been discussed in detail in Date and Gray (1988). Koppenaal (1988, 1990) has reviewed the ICP-MS literature. In that ICP-MS is a relatively new and still evolving technique, this chapter will discuss potential capability more than proven performance. (author). 24 refs

Regulator of G protein signaling 2 (RGS2 and RGS4 form distinct G protein-dependent complexes with protease activated-receptor 1 (PAR1 in live cells.

Directory of Open Access Journals (Sweden)

Sungho Ghil

Full Text Available Protease-activated receptor 1 (PAR1 is a G-protein coupled receptor (GPCR that is activated by natural proteases to regulate many physiological actions. We previously reported that PAR1 couples to Gi, Gq and G12 to activate linked signaling pathways. Regulators of G protein signaling (RGS proteins serve as GTPase activating proteins to inhibit GPCR/G protein signaling. Some RGS proteins interact directly with certain GPCRs to modulate their signals, though cellular mechanisms dictating selective RGS/GPCR coupling are poorly understood. Here, using bioluminescence resonance energy transfer (BRET, we tested whether RGS2 and RGS4 bind to PAR1 in live COS-7 cells to regulate PAR1/Gα-mediated signaling. We report that PAR1 selectively interacts with either RGS2 or RGS4 in a G protein-dependent manner. Very little BRET activity is observed between PAR1-Venus (PAR1-Ven and either RGS2-Luciferase (RGS2-Luc or RGS4-Luc in the absence of Gα. However, in the presence of specific Gα subunits, BRET activity was markedly enhanced between PAR1-RGS2 by Gαq/11, and PAR1-RGS4 by Gαo, but not by other Gα subunits. Gαq/11-YFP/RGS2-Luc BRET activity is promoted by PAR1 and is markedly enhanced by agonist (TFLLR stimulation. However, PAR1-Ven/RGS-Luc BRET activity was blocked by a PAR1 mutant (R205A that eliminates PAR1-Gq/11 coupling. The purified intracellular third loop of PAR1 binds directly to purified His-RGS2 or His-RGS4. In cells, RGS2 and RGS4 inhibited PAR1/Gα-mediated calcium and MAPK/ERK signaling, respectively, but not RhoA signaling. Our findings indicate that RGS2 and RGS4 interact directly with PAR1 in Gα-dependent manner to modulate PAR1/Gα-mediated signaling, and highlight a cellular mechanism for selective GPCR/G protein/RGS coupling.

Interfacing capillary electrophoresis with inductively coupled plasma mass spectrometry by direct injection nebulization for selenium speciation

DEFF Research Database (Denmark)

Bendahl, Lars; Gammelgaard, Bente; Jons, O.

2001-01-01

A demountable direct injection high efficiency nebulizer operating at low sample uptake rates was developed and used for coupling of capillary electrophoresis (CE) with inductively coupled plasma mass spectrometry (ICP-MS). When the nebulizer was used for continuous sample introduction, detection...

Improvement of NiMoNb to polyimide adhesion by inductively coupled nitrogen plasma treatment

Energy Technology Data Exchange (ETDEWEB)

Bang, S.-H., E-mail: zxclucy@snu.ac.kr

2016-01-01

Graphical abstract: - Highlights: • NiMoNb was introduced as the adhesion layer for flexible Cu-clad laminate structure. • The effect of sputtering and plasma power on the peel strength was studied. • Plasma pretreatment in inductively coupled plasma greatly affects the peel strength. • FCCL with NiMoNb adhesion layer show outstanding peel strength. - Abstract: In this study, the effect of sputtering power on the peel strength of the flexible copper clad laminate (FCCL) was evaluated before and after heat treatment using 180° peel test. An increase in the sputtering powers from 200 W to 600 W increased film density and improved peel strength. To enhance peel strength much more, an inductively coupled plasma (ICP) was treated on the PI surface using N{sub 2} gas with Ar as a function of RF power. A dramatic enhancement of the peel strength, 923 N/m was achieved, especially after heat treatment by changing ICP power from 200 W to 900 W. The reduction ratio of the peel strength for the 900 W plasma-treated FCCL was only 12%, whereas that for the 200 W plasma-treated FCCL was 43%. The root mean square (RMS) surface roughness with PIs exposed to both 200 W and 900 W plasma treatments was rarely changed, while X-ray photoelectron spectroscopy (XPS) showed the substantial increase of C–N functional groups. To obtain insight the film characteristics, the NiMoNb/PI interfaces were investigated by a high resolution transmission electron microscopy (HR-TEM).

Stable explicit coupling of the Yee scheme with a linear current model in fluctuating magnetized plasmas

International Nuclear Information System (INIS)

Silva, Filipe da; Pinto, Martin Campos; Després, Bruno; Heuraux, Stéphane

2015-01-01

This work analyzes the stability of the Yee scheme for non-stationary Maxwell's equations coupled with a linear current model with density fluctuations. We show that the usual procedure may yield unstable scheme for physical situations that correspond to strongly magnetized plasmas in X-mode (TE) polarization. We propose to use first order clustered discretization of the vectorial product that gives back a stable coupling. We validate the schemes on some test cases representative of direct numerical simulations of X-mode in a magnetic fusion plasma including turbulence

Line photon transport in a non-homogeneous plasma using radiative coupling coefficients

International Nuclear Information System (INIS)

Florido, R.; Gil, J.M.; Rodriguez, R.; Rubiano, J.G.; Martel, P.; Florido, R.; Gil, J.M.; Rodriguez, R.; Rubiano, J.G.; Martel, P.; Minguez, E.

2006-01-01

We present a steady-state collisional-radiative model for the calculation of level populations in non-homogeneous plasmas with planar geometry. The line photon transport is taken into account following an angle- and frequency-averaged escape probability model. Several models where the same approach has been used can be found in the literature, but the main difference between our model and those ones is that the details of geometry are exactly treated in the definition of coupling coefficients and a local profile is taken into account in each plasma cell. (authors)

Sterilization of beehive material with a double inductively coupled low pressure plasma

International Nuclear Information System (INIS)

Priehn, M; Leichert, L I; Denis, B; Awakowicz, P; Aumeier, P; Kirchner, W H

2016-01-01

American Foulbrood is a severe, notifiable disease of the honey bee. It is caused by infection of bee larvae with spores of the gram-positive bacterium Paenibacillus larvae . Spores of this organism are found in high numbers in an infected hive and are highly resistant to physical and chemical inactivation methods. The procedures to rehabilitate affected apiaries often result in the destruction of beehive material. In this study we assess the suitability of a double inductively coupled low pressure plasma as a non-destructive, yet effective alternative inactivation method for bacterial spores of the model organism Bacillus subtilis on beehive material. Plasma treatment was able to effectively remove spores from wax, which, under protocols currently established in veterinary practice, normally is destroyed by ignition or autoclaved for sterilization. Spores were removed from wooden surfaces with efficacies significantly higher than methods currently used in veterinary practice, such as scorching by flame treatment. In addition, we were able to non-destructively remove spores from the highly delicate honeycomb wax structures, potentially making treatment of beehive material with double inductively coupled low pressure plasma part of a fast and reliable method to rehabilitate infected bee colonies with the potential to re-use honeycombs. (paper)

Battery-powered pulsed high density inductively coupled plasma source for pre-ionization in laboratory astrophysics experiments.

Science.gov (United States)

Chaplin, Vernon H; Bellan, Paul M

2015-07-01

An electrically floating radiofrequency (RF) pre-ionization plasma source has been developed to enable neutral gas breakdown at lower pressures and to access new experimental regimes in the Caltech laboratory astrophysics experiments. The source uses a customized 13.56 MHz class D RF power amplifier that is powered by AA batteries, allowing it to safely float at 3-6 kV with the electrodes of the high voltage pulsed power experiments. The amplifier, which is capable of 3 kW output power in pulsed (<1 ms) operation, couples electrical energy to the plasma through an antenna external to the 1.1 cm radius discharge tube. By comparing the predictions of a global equilibrium discharge model with the measured scalings of plasma density with RF power input and axial magnetic field strength, we demonstrate that inductive coupling (rather than capacitive coupling or wave damping) is the dominant energy transfer mechanism. Peak ion densities exceeding 5 × 10(19) m(-3) in argon gas at 30 mTorr have been achieved with and without a background field. Installation of the pre-ionization source on a magnetohydrodynamically driven jet experiment reduced the breakdown time and jitter and allowed for the creation of hotter, faster argon plasma jets than was previously possible.

Initial design for an experimental investigation of strongly coupled plasma behavior in the ATLAS facility

CERN Document Server

Munson, C P; Taylor, A J; Trainor, R J; Wood, B P; Wysocki, F J

1999-01-01

Summary form only given. Atlas is a high current (~30 MA peak, with a current risetime ~4.5 mu sec), high energy (E/sub stored/=24 MJ, E /sub load/=3-6 MJ), pulsed power facility which is being constructed at Los Alamos National Laboratory with a scheduled completion date in the year 2000. When operational, this facility will provide a platform for experiments in high pressure shocks (>20 Mbar), adiabatic compression ( rho / rho /sub 0/>5, P>10 Mbar), high magnetic fields (~2000 T), high strain and strain rates ( epsilon >200, d epsilon /dt~10/sup 4/ to 10/sup 6/ s/sup -1/), hydrodynamic instabilities of materials in turbulent regimes, magnetized target fusion, equation of state, and strongly coupled plasmas. For the strongly coupled plasma experiments, an auxiliary capacitor bank will be used to generate a moderate density (<0.1 solid), relatively cold (~1 eV) plasma by ohmic heating of a conducting material of interest such as titanium. This target plasma will be compressed against a central column conta...

Atlas of atomic spectral lines of plutonium emitted by an inductively coupled plasma

Energy Technology Data Exchange (ETDEWEB)

Edelson, M.C.; DeKalb, E.L.; Winge, R.K.; Fassel, V.A.

1986-09-01

Optical emission spectra from high-purity Pu-242 were generated with a glovebox-enclosed inductively coupled plasma (ICP) source. Spectra covering the 2280 to 7008 Angstrom wavelength range are presented along with general commentary on ICP-Pu spectroscopy.

Separation and analysis of lanthanides by isotachophoresis coupled with inductively coupled plasma mass spectrometry

International Nuclear Information System (INIS)

Vio, Laurent; Cretier, Gerard; Rocca, Jean-Louis; Chartier, Frederic; Geertsen, Valerie; Gourgiotis, Alkiviadis; Isnard, Helene

2012-01-01

This study is a large project initiated by the French Nuclear Agency, and concerns the development of a new electrolyte system for the separation of lanthanides by isotachophoresis. This new system is based on a leading electrolyte that incorporates 2-hydroxy-2-methylbutyric acid as complexing agent. The optimization of separation conditions (complexing agent concentration, pH, capillary dimensions, injection conditions, and current intensity) performed by experiments on a commercial capillary instrument with contactless conductivity detection, which allows to improve the separation of 13 lanthanides (La to Lu, except Pm and Ho). We have also directly coupled the isotachophoresis to an inductively coupled plasma mass spectrometer to visualize the mono-elementary elution bands and demonstrate the potentiality of the method for isotope ratio measurements. The application to a simulated solution representative of a fraction of fission products present in a MOX spent fuel is presented in this paper to demonstrate the possible application in future on nuclear fuel samples. (authors)

Urine suPAR levels compared with plasma suPAR levels as predictors of post-consultation mortality risk among individuals assumed to be TB-negative: a prospective cohort study

DEFF Research Database (Denmark)

Rabna, Paulo; Andersen, Andreas; Wejse, Christian

2010-01-01

-suPAR was measured using a commercial ELISA (suPARnostic®). We found that U-suPAR carried significant prognostic information on mortality for HIV-infected subjects with an area under the ROC curve of 0.75. For HIV-negative individuals, little or no prognostic effect was observed. However, in both HIV positives...... and negatives, the predictive effect of U-suPAR was found to be inferior to that of P-suPAR....

Quantum screening effects on the electron-ion occurrence scattering time advance in strongly coupled semiclassical plasmas

International Nuclear Information System (INIS)

Song, Mi-Young; Jung, Young-Dae

2003-01-01

Quantum screening effects on the occurrence scattering time advance for elastic electron-ion collisions in strongly coupled semiclassical plasmas are investigated using the second-order eikonal analysis. The electron-ion interaction in strongly coupled semiclassical plasmas is obtained by the pseudopotential model taking into account the plasma screening and quantum effects. It is found that the quantum-mechanical effects significantly reduce the occurrence scattering time advance. It is also found that the occurrence scattering time advance increases with increasing Debye length. It is quite interesting to note that the domain of the maximum occurrence time advance is localized for the forward scattering case. The region of the scaled thermal de Broglie wave length (λ-bar) for the maximum occurrence time advance is found to be 0.4≤λ-bar≤1.4

Assessment of high precision, high accuracy Inductively Coupled Plasma-Optical Emission Spectroscopy to obtain concentration uncertainties less than 0.2% with variable matrix concentrations

International Nuclear Information System (INIS)

Rabb, Savelas A.; Olesik, John W.

2008-01-01

The ability to obtain high precision, high accuracy measurements in samples with complex matrices using High Performance Inductively Coupled Plasma-Optical Emission Spectroscopy (HP-ICP-OES) was investigated. The Common Analyte Internal Standard (CAIS) procedure was incorporated into the High Performance Inductively Coupled Plasma-Optical Emission Spectroscopy method to correct for matrix-induced changes in emission intensity ratios. Matrix matching and standard addition approaches to minimize matrix-induced errors when using High Performance Inductively Coupled Plasma-Optical Emission Spectroscopy were also assessed. The High Performance Inductively Coupled Plasma-Optical Emission Spectroscopy method was tested with synthetic solutions in a variety of matrices, alloy standard reference materials and geological reference materials

Inductively coupled plasma emission spectroscopy. Part II: applications and fundamentals. Volume 2

International Nuclear Information System (INIS)

Boumans, P.W.J.M.

1987-01-01

This is the second part of the two-volume treatise by this well-known and respected author. This volume reviews applications of inductively coupled plasma atomic emission spectroscopy (ICP-AES), summarizes fundamental studies, and compares ICP-AES methods with other methods of analysis. The first six chapters are devoted to specific fields of application, including the following: metals and other industrial materials, geology, the environment, agriculture and food, biology and clinical analysis, and organic materials. The chapter on the analysis of organic materials also covers the special instrumental considerations required when organic solvents are introduced into an inductively coupled plasma. A chapter on the direct analysis of solids completes the first part of this volume. Each of the applications chapters begins with a summary of the types of samples that are encountered in that field, and the kinds of problems that an elemental analysis can help to solve. This is followed by a tutorial approach covering applicability, advantages, and limitations of the methods. The coverage is thorough, including sample handling, storage, and preparation, acid, and fusion dissolution, avoiding contamination, methods of preconcentration, the types of interferences that can be expected and ways to reduce them, and the types of ICP plasmas that are used. The second half of the volume covers fundamental studies of ICP-AES: basic processes of aerosol generation, plasma modeling and computer simulation, spectroscopic diagnostics, excitation mechanisms, and discharge characteristics. This section introduces the experimental and modeling methods that have been used to obtain fundamental information about ICPs

Determination of trace elements in petroleum products by inductively coupled plasma techniques: A critical review

International Nuclear Information System (INIS)

Sánchez, Raquel; Todolí, José Luis; Lienemann, Charles-Philippe; Mermet, Jean-Michel

2013-01-01

The fundamentals, applications and latter developments of petroleum products analysis through inductively coupled plasma optical emission spectrometry (ICP-OES) and mass spectrometry (ICP-MS) are revisited in the present bibliographic survey. Sample preparation procedures for the direct analysis of fuels by using liquid sample introduction systems are critically reviewed and compared. The most employed methods are sample dilution, emulsion or micro-emulsion preparation and sample decomposition. The first one is the most widely employed due to its simplicity. Once the sample has been prepared, an organic matrix is usually present. The performance of the sample introduction system (i.e., nebulizer and spray chamber) depends strongly upon the nature and properties of the solution finally obtained. Many different devices have been assayed and the obtained results are shown. Additionally, samples can be introduced into the plasma by using an electrothermal vaporization (ETV) device or a laser ablation system (LA). The recent results published in the literature showing the feasibility, advantages and drawbacks of latter alternatives are also described. Therefore, the main goal of the review is the discussion of the different approaches developed for the analysis of crude oil and its derivates by inductively coupled plasma (ICP) techniques. - Highlights: • Analysis of petroleum products by inductively coupled plasma techniques is revisited. • Fundamental studies are included together with reports dealing with applications. • Conventional and non-conventional sample introduction methods are considered. • Sample preparation methods are critically compared and described

Room temperature inductively coupled plasma etching of InAs/InSb in BCl 3/Cl 2/Ar

KAUST Repository

Sun, Jian; Kosel, Jü rgen

2012-01-01

Inductively coupled plasma (ICP) etching of InAs and InSb at room temperature has been investigated using BCl 3/Cl 2/Ar plasma. Specifically, the etch rate and post-etching surface morphology were investigated as functions of the gas composition

Flow injection analysis in inductively coupled plasma spectrometry

International Nuclear Information System (INIS)

Rosias, Maria F.G.G.

1995-10-01

The main features of flow injection analysis (FIA) as contribution to the inductively coupled plasma (Icp) spectrometry are described. A systematic review of researches using the combined FIA-Icp and the benefits of this association are presented. Flow systems were proposed to perform on-line Icp solution management for multielemental determination by atomic emission spectrometry (Icp-AES) or mass spectrometry. The inclusion of on-line ion exchangers in flow systems for matrix separation and/or analyte preconcentration are presented. Together with those applications the new advent of instruments with facilities for multielement detection on flow injection signals are described. (author). 75 refs., 19 figs

Drag force in a strongly coupled anisotropic plasma

Science.gov (United States)

Chernicoff, Mariano; Fernández, Daniel; Mateos, David; Trancanelli, Diego

2012-08-01

We calculate the drag force experienced by an infinitely massive quark propagating at constant velocity through an anisotropic, strongly coupled {N} = 4 plasma by means of its gravity dual. We find that the gluon cloud trailing behind the quark is generally misaligned with the quark velocity, and that the latter is also misaligned with the force. The drag coefficient μ can be larger or smaller than the corresponding isotropic value depending on the velocity and the direction of motion. In the ultra-relativistic limit we find that generically μ ∝ p. We discuss the conditions under which this behaviour may extend to more general situations.

Modeling of magnetically enhanced capacitively coupled plasma sources: Ar discharges

International Nuclear Information System (INIS)

Kushner, Mark J.

2003-01-01

Magnetically enhanced capacitively coupled plasma sources use transverse static magnetic fields to modify the performance of low pressure radio frequency discharges. Magnetically enhanced reactive ion etching (MERIE) sources typically use magnetic fields of tens to hundreds of Gauss parallel to the substrate to increase the plasma density at a given pressure or to lower the operating pressure. In this article results from a two-dimensional hybrid-fluid computational investigation of MERIE reactors with plasmas sustained in argon are discussed for an industrially relevant geometry. The reduction in electron cross field mobility as the magnetic field increases produces a systematic decrease in the dc bias (becoming more positive). This decrease is accompanied by a decrease in the energy and increase in angular spread of the ion flux to the substrate. Similar trends are observed when decreasing pressure for a constant magnetic field. Although for constant power the magnitudes of ion fluxes to the substrate increase with moderate magnetic fields, the fluxes decreased at larger magnetic fields. These trends are due, in part, to a reduction in the contributions of more efficient multistep ionization

Capacitively coupled radio-frequency plasmas excited by tailored voltage waveforms

International Nuclear Information System (INIS)

Lafleur, T; Delattre, P A; Booth, J P; Johnson, E V

2013-01-01

By applying certain types of ‘tailored’ voltage waveforms (TVWs) to capacitively coupled plasmas, a dc self-bias and an asymmetric plasma response can be produced, even in geometrically symmetric reactors. Furthermore, these arbitrary applied waveforms can produce a number of interesting phenomena that are not present in typical single-frequency sinusoidal discharges. This electrical asymmetry effect presents emerging possibilities for the improved control of the ion energy and ion flux in these systems; parameters of vital importance to both etching and deposition applications for materials processing. With a combined research approach utilizing both experimental measurements, and particle-in-cell simulations, we review and extend recent investigations that study a particular class of TVW. The waveforms used have a pulse-type shape and are composed of a varying number of harmonic frequencies. This allows a strong self-bias to be produced, and causes most of the applied voltage to be dropped across a single sheath. Additionally, decreasing the pulse width (by increasing the number of harmonics), allows the plasma density and ion flux to be increased. Simulation and experimental results both demonstrate that this type of waveform can be used to separately control the ion flux and ion energy, while still producing a uniform plasma over large area (50 cm diameter) rf electrodes. (paper)

A method for studies on interactions between a gold-based drug and plasma proteins based on capillary electrophoresis with inductively coupled plasma mass spectrometry detection

DEFF Research Database (Denmark)

Nguyen, Tam T T N; Østergaard, Jesper; Gammelgaard, Bente

2015-01-01

An analytical method based on capillary electrophoresis (CE) and inductively coupled plasma mass spectrometry (ICP-MS) detection was developed for studies on the interaction of gold-containing drugs and plasma proteins using auranofin as example. A detection limit of 18 ng/mL of auranofin corresp...

Viscosity calculated in simulations of strongly coupled dusty plasmas with gas friction

International Nuclear Information System (INIS)

Feng Yan; Goree, J.; Liu Bin

2011-01-01

A two-dimensional strongly coupled dusty plasma is modeled using Langevin and frictionless molecular dynamical simulations. The static viscosity η and the wave-number-dependent viscosity η(k) are calculated from the microscopic shear in the random motion of particles. A recently developed method of calculating the wave-number-dependent viscosity η(k) is validated by comparing the results of η(k) from the two simulations. It is also verified that the Green-Kubo relation can still yield an accurate measure of the static viscosity η in the presence of a modest level of friction as in dusty plasma experiments.

Characterization of a rotating nanoparticle cloud in an inductively coupled plasma

International Nuclear Information System (INIS)

Schulze, M; Keudell, A von; Awakowicz, P

2006-01-01

Carbon clusters with diameters in the range of 10 to 50 nm are produced by injecting pulses of acetylene into an inductively coupled plasma in argon and helium. The injection causes plasma instability, which becomes visible as an oscillation of the emission intensity. The frequency of this oscillation can be uniquely correlated to the particle diameter. Consequently, the measurement of the oscillation frequency represents a method to determine particle diameters in situ. The oscillation corresponds to the rotation of a localized plasmoid and a particle cloud around the symmetry axis of the reactor. It is assumed that this rotation is driven by the ion wind crossing the interface between the plasmoid and the particle cloud

Aerosol Vacuum-Assisted Plasma Ionization (Aero-VaPI) Coupled to Ion Mobility-Mass Spectrometry

Science.gov (United States)

Blair, Sandra L.; Ng, Nga L.; Zambrzycki, Stephen C.; Li, Anyin; Fernández, Facundo M.

2018-02-01

In this communication, we report on the real-time analysis of organic aerosol particles by Vacuum-assisted Plasma Ionization-Mass Spectrometry (Aero-VaPI-MS) using a home-built VaPI ion source coupled to a Synapt G2-S HDMS ion mobility-mass spectrometry (IM-MS) system. Standards of organic molecules of interest in prebiotic chemistry were used to generate aerosols. Monocaprin and decanoic acid aerosol particles were successfully detected in both the positive and negative ion modes, respectively. A complex aerosol mixture of different sizes of polymers of L-malic acid was also examined through ion mobility (IM) separations, resulting in the detection of polymers of up to eight monomeric units. This noncommercial plasma ion source is proposed as a low cost alternative to other plasma ionization platforms used for aerosol analysis, and a higher-performance alternative to more traditional aerosol mass spectrometers. VaPI provides robust online ionization of organics in aerosols without extensive ion activation, with the coupling to IM-MS providing higher peak capacity and excellent mass accuracy. [Figure not available: see fulltext.

The concept of coupling impedance in the self-consistent plasma wake field excitation

International Nuclear Information System (INIS)

Fedele, R.; Akhter, T.; De Nicola, S.; Migliorati, M.; Marocchino, A.; Massimo, F.; Palumbo, L.

2016-01-01

Within the framework of the Vlasov–Maxwell system of equations, we describe the self-consistent interaction of a relativistic charged-particle beam with the surroundings while propagating through a plasma-based acceleration device. This is done in terms of the concept of coupling (longitudinal) impedance in full analogy with the conventional accelerators. It is shown that also here the coupling impedance is a very useful tool for the Nyquist-type stability analysis. Examples of specific physical situations are finally illustrated.

Influence of the low-frequency source parameters on the plasma characteristics in a dual frequency capacitively coupled plasma reactor: Two dimensional simulations

Institute of Scientific and Technical Information of China (English)

Xiang Xu; Hao Ge; Shuai Wang; Zhongling Dai; Younian Wang; Aimin Zhu

2009-01-01

A two-dimensional (2D) fluid model is presented to study the discharge of argon in a dual frequency capacitively coupled plasma (CCP) reactor. We are interested in the influence of low-frequency (LF) source parameters such as applied voltage amplitudes and low frequencies on the plasma characteristics. In this paper, the high frequency is set to 60 MHz with voltage 50 V. The simulations were carried out for low frequencies of 1, 2 and 6 MHz with LF voltage 100 V, and for LF voltages of 60, 90 and 120 V with low frequency 2 MHz. The results of 2D distributions of electric field and ion density, the ion flux impinging on the substrate and the ion energy on the powered electrode are shown. As the low frequency increases, two sources become from uncoupling to coupling, When two sources are uncoupling, the increase in LF has little impact on the plasma characteristics, but when two sources are coupling, the increase in LF decreases the uniformities of ion density and ion flux noticeably. It is also found that with the increase in LF voltage, the uniformities in the radial direction of ion density distribution and ion flux at the powered electrode decreases significantly, and the energy of ions bombarding on the powered electrode increases significantly.

PAR1 activation affects the neurotrophic properties of Schwann cells.

Science.gov (United States)

Pompili, Elena; Fabrizi, Cinzia; Somma, Francesca; Correani, Virginia; Maras, Bruno; Schininà, Maria Eugenia; Ciraci, Viviana; Artico, Marco; Fornai, Francesco; Fumagalli, Lorenzo

2017-03-01

Protease-activated receptor-1 (PAR1) is the prototypic member of a family of four G-protein-coupled receptors that signal in response to extracellular proteases. In the peripheral nervous system, the expression and/or the role of PARs are still poorly investigated. High PAR1 mRNA expression was found in the rat dorsal root ganglia and the signal intensity of PAR1 mRNA increased in response to sciatic nerve transection. In the sciatic nerve, functional PAR1 receptor was reported at the level of non-compacted Schwann cell myelin microvilli of the nodes of Ranvier. Schwann cells are the principal population of glial cells of the peripheral nervous system which myelinate axons playing an important role during axonal regeneration and remyelination. The present study was undertaken in order to determine if the activation of PAR1 affects the neurotrophic properties of Schwann cells. Our results suggest that the stimulation of PAR1 could potentiate the Schwann cell ability to favour nerve regeneration. In fact, the conditioned medium obtained from Schwann cell cultures challenged with a specific PAR1 activating peptide (PAR1 AP) displays increased neuroprotective and neurotrophic properties with respect to the culture medium from untreated Schwann cells. The proteomic analysis of secreted proteins in untreated and PAR1 AP-treated Schwann cells allowed the identification of factors differentially expressed in the two samples. Some of them (such as macrophage migration inhibitory factor, matrix metalloproteinase-2, decorin, syndecan 4, complement C1r subcomponent, angiogenic factor with G patch and FHA domains 1) appear to be transcriptionally regulated after PAR1 AP treatment as shown by RT-PCR. Copyright © 2017 Elsevier Inc. All rights reserved.

Determination of platinum in human subcellular microsamples by inductively coupled plasma mass spectrometry

DEFF Research Database (Denmark)

Björn, Erik; Nygren, Yvonne; Nguyen, Tam T. T. N.

2007-01-01

A fast and robust method for the determination of platinum in human subcellular microsamples by inductively coupled plasma mass spectrometry was developed, characterized, and validated. Samples of isolated DNA and exosome fractions from human ovarian (2008) and melanoma (T289) cancer cell lines w...

Strongly coupled Coulomb systems with positive dust grains: thermal and UV-induced plasmas

International Nuclear Information System (INIS)

Samarian, A.A.

2000-01-01

Full text: A plasma containing macroscopic dust particles or grains (often referred to as a dusty or colloidal or complex plasma) has the feature that grains may be charged by electron or ion flux or by photo- or thermoelectron emission. Electron emission from a grain surface produces a positive charge; capture of electrons produces the reverse effect making the dust grains negatively charged. Most dusty plasma research is concerned with the ordered dust structures (so-called 'plasma crystal') in glow discharges. The dust grains in these experiments were found to carry a negative charge due to the higher mobility of electrons as compared to ions in the discharge plasma. In recent years, in parallel with the study of the properties of plasma crystals under discharge conditions, attempts to obtain a structure from positively charged dust grains have been made, and structure formation processes for various charging mechanisms, particularly thermoelectron emission and photoemission, have been investigated. In this paper we review the essential features of strongly coupled plasmas with positive dust grains. An ordered structure of CeO 2 grains has been experimentally observed in a combustion products jet. The grains were charged positively and suspended in the plasma flow. Their charge is about 10 3 a and the calculated value of a Coulomb coupling parameter Γ is >10, corresponding to a plasma liquid. The ordered structures of Al 2 O 3 dust grains in propellant combustion products plasma have been observed for the first time. These structures were found in the sheath boundary of condensation region. The obtained data let us estimate the value of parameter Γ =3-40, corresponding to the plasma liquid state. The possibility is studied of the formation of ordered dust grain structures in thermal plasma. The range of the required values of the coupling parameter Γ is calculated using the results of diagnostic measurements carried out in thermal plasma with grains of

Trace metal analysis of road dust by inductively coupled plasma mass spectrometry

International Nuclear Information System (INIS)

Powell, M.J.; Liu, L.; Gnanalingham, N.; Peters, L.

2000-01-01

Dust from roads in an air impingement zone close to anthropogenic sources of air pollutants can be a concern for people living in the immediate vicinity. The Ministry of the Environment (MOE) has conducted a case study to monitor the concentration of uranium, strontium, thorium and arsenic in road dust from one such area. A method for the analysis of road dust by inductively coupled plasma mass spectrometry (ICP-MS) has been developed with detection limits in the ng/1 range. A digestion technique has been developed by conducting experiments using single and combinations of acids in open-vessel wet digestions. Accuracy has been determined by the use of matrix representative certified reference materials (CRMs). Digestion precision was determined by elemental concentration measurements of the most representative CRM through replicates. Spike recovery data were from 95% to 110% for all elements, and inter-method comparison studies between hydride generation atomic absorption spectrometry (AAS) inductively coupled plasma atomic emission spectrometry (ICP-AES) and ICP-MS for arsenic and strontium show good agreement. (author)

Initial design for an experimental investigation of strongly coupled plasma behavior in the Atlas facility

Energy Technology Data Exchange (ETDEWEB)

Munson, C.P.; Benage, J.F. Jr.; Taylor, A.J.; Trainor, R.J. Jr.; Wood, B.P.; Wysocki, F.J.

1999-07-01

Atlas is a high current ({approximately} 30 MA peak, with a current risetime {approximately} 4.5 {micro}sec), high energy (E{sub stored} = 24 MJ, E{sub load} = 3--6 MJ), pulsed power facility which is being constructed at Los Alamos National Laboratory with a scheduled completion date in the year 2000. When operational, this facility will provide a platform for experiments in high pressure shocks (> 20 Mbar), adiabatic compression ({rho}/{rho}{sub 0} > 5, P > 10 Mbar), high magnetic fields ({approximately} 2,000 T), high strain and strain rates ({var_epsilon} > 200%, d{var_epsilon}/dt {approximately} 10{sup 4} to 10{sup 6} s{sup {minus}1}), hydrodynamic instabilities of materials in turbulent regimes, magnetized target fusion, equation of state, and strongly coupled plasmas. For the strongly coupled plasma experiments, an auxiliary capacitor bank will be used to generate a moderate density (< 0.1 solid), relatively cold ({approximately} 1 eV) plasma by ohmic heating of a conducting material of interest such as titanium. This stargate plasma will be compressed against a central column containing diagnostic instrumentation by a cylindrical conducting liner that is driven radially inward by current from the main Atlas capacitor bank. The plasma is predicted to reach densities of {approximately} 1.1 times solid, achieve ion and electron temperatures of {approximately} 10 eV, and pressures of {approximately} 4--5 Mbar. This is a density/temperature regime which is expected to experience strong coupling, but only partial degeneracy. X-ray radiography is planned for measurements of the material density at discrete times during the experiments; diamond Raman measurements are anticipated for determination of the pressure. In addition, a neutron resonance spectroscopic technique is being evaluated for possible determination of the temperature (through low percentage doping of the titanium with a suitable resonant material). Initial target plasma formation experiments are

Initial design for an experimental investigation of strongly coupled plasma behavior in the Atlas facility

International Nuclear Information System (INIS)

Munson, C.P.; Benage, J.F. Jr.; Taylor, A.J.; Trainor, R.J. Jr.; Wood, B.P.; Wysocki, F.J.

1999-01-01

Atlas is a high current (approximately 30 MA peak, with a current risetime approximately 4.5 microsec), high energy (E stored = 24 MJ, E load = 3--6 MJ), pulsed power facility which is being constructed at Los Alamos National Laboratory with a scheduled completion date in the year 2000. When operational, this facility will provide a platform for experiments in high pressure shocks (> 20 Mbar), adiabatic compression (ρ/ρ 0 > 5, P > 10 Mbar), high magnetic fields (approximately 2,000 T), high strain and strain rates (var e psilon > 200%, dvar e psilon/dt approximately 10 4 to 10 6 s -1 ), hydrodynamic instabilities of materials in turbulent regimes, magnetized target fusion, equation of state, and strongly coupled plasmas. For the strongly coupled plasma experiments, an auxiliary capacitor bank will be used to generate a moderate density (< 0.1 solid), relatively cold (approximately 1 eV) plasma by ohmic heating of a conducting material of interest such as titanium. This stargate plasma will be compressed against a central column containing diagnostic instrumentation by a cylindrical conducting liner that is driven radially inward by current from the main Atlas capacitor bank. The plasma is predicted to reach densities of approximately 1.1 times solid, achieve ion and electron temperatures of approximately 10 eV, and pressures of approximately 4--5 Mbar. This is a density/temperature regime which is expected to experience strong coupling, but only partial degeneracy. X-ray radiography is planned for measurements of the material density at discrete times during the experiments; diamond Raman measurements are anticipated for determination of the pressure. In addition, a neutron resonance spectroscopic technique is being evaluated for possible determination of the temperature (through low percentage doping of the titanium with a suitable resonant material). Initial target plasma formation experiments are being planned on an existing pulsed power facility at LANL and

Multiplex bio-assay with inductively coupled plasma mass spectrometry: Towards a massively multivariate single-cell technology

International Nuclear Information System (INIS)

Tanner, Scott D.; Ornatsky, Olga; Bandura, Dmitry R.; Baranov, Vladimir I.

2007-01-01

Recent progress in the development of massively multiplexed bioanalytical assays using element tags with inductively coupled plasma mass spectrometry detection is reviewed. Feasibility results using commercially available secondary immunolabeling reagents for leukemic cell lines are presented. Multiplex analysis of higher order is shown with first generation tag reagents based on functionalized carriers that bind lanthanide ions. DNA quantification using metallointercalation allows for cell enumeration or mitotic state differentiation. In situ hybridization permits the determination of cellular RNA. The results provide a feasibility basis for the development of a multivariate assay tool for individual cell analysis based on inductively coupled plasma mass spectrometry in a cytometer configuration

Multiplex bio-assay with inductively coupled plasma mass spectrometry: Towards a massively multivariate single-cell technology

Energy Technology Data Exchange (ETDEWEB)

Tanner, Scott D. [Institute of Biomaterials and Biomedical Engineering, University of Toronto, Room 407, 164 College Street, Toronto, Ontario, M5S 3G9 (Canada)], E-mail: sd.tanner@utoronto.ca; Ornatsky, Olga; Bandura, Dmitry R.; Baranov, Vladimir I. [Institute of Biomaterials and Biomedical Engineering, University of Toronto, Room 407, 164 College Street, Toronto, Ontario, M5S 3G9 (Canada)

2007-03-15

Recent progress in the development of massively multiplexed bioanalytical assays using element tags with inductively coupled plasma mass spectrometry detection is reviewed. Feasibility results using commercially available secondary immunolabeling reagents for leukemic cell lines are presented. Multiplex analysis of higher order is shown with first generation tag reagents based on functionalized carriers that bind lanthanide ions. DNA quantification using metallointercalation allows for cell enumeration or mitotic state differentiation. In situ hybridization permits the determination of cellular RNA. The results provide a feasibility basis for the development of a multivariate assay tool for individual cell analysis based on inductively coupled plasma mass spectrometry in a cytometer configuration.

Experimental observation of strong coupling effects on the dispersion of dust acoustic waves in a plasma

Energy Technology Data Exchange (ETDEWEB)

Bandyopadhyay, P. [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)], E-mail: pintu@ipr.res.in; Prasad, G.; Sen, A.; Kaw, P.K. [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)

2007-09-03

The dispersion properties of low frequency dust acoustic waves in the strong coupling regime are investigated experimentally in an argon plasma embedded with a mixture of kaolin and MnO{sub 2} dust particles. The neutral pressure is varied over a wide range to change the collisional properties of the dusty plasma. In the low collisional regime the turnover of the dispersion curve at higher wave numbers and the resultant region of {partial_derivative}{omega}/{partial_derivative}k<0 are identified as signatures of dust-dust correlations. In the high collisional regime dust neutral collisions produce a similar effect and prevent an unambiguous identification of strong coupling effects.

Experimental observation of strong coupling effects on the dispersion of dust acoustic waves in a plasma

International Nuclear Information System (INIS)

Bandyopadhyay, P.; Prasad, G.; Sen, A.; Kaw, P.K.

2007-01-01

The dispersion properties of low frequency dust acoustic waves in the strong coupling regime are investigated experimentally in an argon plasma embedded with a mixture of kaolin and MnO 2 dust particles. The neutral pressure is varied over a wide range to change the collisional properties of the dusty plasma. In the low collisional regime the turnover of the dispersion curve at higher wave numbers and the resultant region of ∂ω/∂k<0 are identified as signatures of dust-dust correlations. In the high collisional regime dust neutral collisions produce a similar effect and prevent an unambiguous identification of strong coupling effects

Experimental observation of strong coupling effects on the dispersion of dust acoustic waves in a plasma

Science.gov (United States)

Bandyopadhyay, P.; Prasad, G.; Sen, A.; Kaw, P. K.

2007-09-01

The dispersion properties of low frequency dust acoustic waves in the strong coupling regime are investigated experimentally in an argon plasma embedded with a mixture of kaolin and MnO2 dust particles. The neutral pressure is varied over a wide range to change the collisional properties of the dusty plasma. In the low collisional regime the turnover of the dispersion curve at higher wave numbers and the resultant region of ∂ω/∂k<0 are identified as signatures of dust dust correlations. In the high collisional regime dust neutral collisions produce a similar effect and prevent an unambiguous identification of strong coupling effects.

Comparison of inductively coupled plasma mass spectrometry with inductively coupled plasma atomic emission spectrometry and instrumental neutron activation analysis for the determination of rare earth elements in Greek bauxites

International Nuclear Information System (INIS)

Ochsenkuehn-Petropoulou, Maria; Luck, Joachim

1991-01-01

Fore the determination of rare earth elements (REE) in bauxitic materials the techniques of inductively coupled plasma mass spectrometry (ICP-MS), inductively coupled plasma atomic emission spectrometry (ICP-AES) and instrumental neutron activation analysis (INAA) were compared. In the NIST (National Institute of Standards and Technology) bauxites SRM 697 Dominican, and SRM 69 b Arkansas, the concentration of some REEs were determined. With the reference bauxite BX-N of the ARNT (Association Nationale de la Recherche Technique) the precision and accuracy of ICP-AES for the determination of REEs in bauxites was tested. Furthermore, Greek bauxites of the Parnassos-Giona area were investigated. In a comparison of the three methods it was possible to calculate from the data series the precision of each method, which showed that the tendency found in the deviations for the different REEs is in accordance with published values. Also the limits of detection for REEs in bauxites were calculated and found to be in the same range as those in the literature. (author)

Beam-plasma coupling physics in support of active experiments

Science.gov (United States)

Yakymenko, K.; Delzanno, G. L.; Roytershteyn, V.

2017-12-01

The recent development of compact relativistic accelerators might open up a new era of active experiments in space, driven by important scientific and national security applications. Examples include using electron beams to trace magnetic field lines and establish causality between physical processes occurring in the magnetosphere and those in the ionosphere. Another example is the use of electron beams to trigger waves in the near-Earth environment. Waves could induce pitch-angle scattering and precipitation of energetic electrons, acting as an effective radiation belt remediation scheme. In this work, we revisit the coupling between an electron beam and a magnetized plasma in the framework of linear cold-plasma theory. We show that coupling can occur through two different regimes. In the first, a non-relativistic beam radiates through whistler waves. This is well known, and was in fact the focus of many rockets and space-shuttle campaigns aimed at demonstrating whistler emissions in the eighties. In the second regime, the beam radiates through extraordinary (R-X) modes. Nonlinear simulations with a highly-accurate Vlasov code support the theoretical results qualitatively and demonstrate that the radiated power through R-X modes can be much larger than in the whistler regime. Test-particle simulations in the wave electromagnetic field will also be presented to assess the efficiency of these waves in inducing pitch-angle scattering via wave-particle interactions. Finally, the implications of these results for a rocket active experiment in the ionosphere and for a radiation belt remediation scheme will be discussed.

Polymerization by plasma of trichloroethylene by means of resistive and inductive coupling

International Nuclear Information System (INIS)

Vasquez, M.; Cruz, G.; Olayo, M.G.; Timoshina, T.; Morales, J.; Olayo, R.

2004-01-01

It was carried out the polymerization for plasma of the trichloroethylene by means of two types of coupling, resistive and inductive with the objective of studying the structure, morphology and the electric properties of the polymers obtained under these conditions. The structure and morphology of the polymers were studied by means of EDS and FT-IR spectroscopies. (Author)

Hydrogen atom kinetics in capacitively coupled plasmas

Science.gov (United States)

Nunomura, Shota; Katayama, Hirotaka; Yoshida, Isao

2017-05-01

Hydrogen (H) atom kinetics has been investigated in capacitively coupled very high frequency (VHF) discharges at powers of 16-780 mW cm-2 and H2 gas pressures of 0.1-2 Torr. The H atom density has been measured using vacuum ultra violet absorption spectroscopy (VUVAS) with a micro-discharge hollow cathode lamp as a VUV light source. The measurements have been performed in two different electrode configurations of discharges: conventional parallel-plate diode and triode with an intermediate mesh electrode. We find that in the triode configuration, the H atom density is strongly reduced across the mesh electrode. The H atom density varies from ˜1012 cm-3 to ˜1010 cm-3 by crossing the mesh with 0.2 mm in thickness and 36% in aperture ratio. The fluid model simulations for VHF discharge plasmas have been performed to study the H atom generation, diffusion and recombination kinetics. The simulations suggest that H atoms are generated in the bulk plasma, by the electron impact dissociation (e + H2 \\to e + 2H) and the ion-molecule reaction (H2 + + H2 \\to {{{H}}}3+ + H). The diffusion of H atoms is strongly limited by a mesh electrode, and thus the mesh geometry influences the spatial distribution of the H atoms. The loss of H atoms is dominated by the surface recombination.

Real-time control of electron density in a capacitively coupled plasma

International Nuclear Information System (INIS)

Keville, Bernard; Gaman, Cezar; Turner, Miles M.; Zhang Yang; Daniels, Stephen; Holohan, Anthony M.

2013-01-01

Reactive ion etching (RIE) is sensitive to changes in chamber conditions, such as wall seasoning, which have a deleterious effect on process reproducibility. The application of real time, closed loop control to RIE may reduce this sensitivity and facilitate production with tighter tolerances. The real-time, closed loop control of plasma density with RF power in a capacitively coupled argon plasma using a hairpin resonance probe as a sensor is described. Elementary control analysis shows that an integral controller provides stable and effective set point tracking and disturbance attenuation. The trade off between performance and robustness may be quantified in terms of one parameter, namely the position of the closed loop pole. Experimental results are presented, which are consistent with the theoretical analysis.

Plasma soluble urokinase plasminogen activator receptor in children with urinary tract infection

DEFF Research Database (Denmark)

Wittenhagen, Per; Andersen, Jesper Brandt; Hansen, Anita

2011-01-01

In this prospective study we investigated the role of plasma levels of soluble urokinase plasminogen activator receptor (suPAR) in children with urinary tract infection.......In this prospective study we investigated the role of plasma levels of soluble urokinase plasminogen activator receptor (suPAR) in children with urinary tract infection....

Coupled plasma-neutral transport model for the scrape-off region

International Nuclear Information System (INIS)

Galambos, J.D.; Peng, Y.K.M.; Heifetz, D.

1985-03-01

Analysis of the scrape-off region requires treatment of the plasma transport along and across the field lines and inclusion of the neutral transport effects. A method for modeling the scrape-off region that is presented here uses separate models for each of these aspects that are coupled together through an iteration procedure that requires only minimal numerical effort. The method is applied here to estimate the neutral pumping rates in the pump-limiter and divertor options for a proposed deuterium-tritium (D-T) ignition experiment. High neutral recycling in the vicinity of the neutralizer plate dramatically affects pumping rates for both the pump-limiter and divertor. In both cases, the plasma flow into the channel surrounding the neutralizer plate is greatly reduced by the neutral recycling. The fraction of this flow that is pumped can be large (> 50%), but in general it is dependent on the particular geometry and plasma conditions. It is estimated that pumping speeds approximately greater than 10 5 L/s are adequate for the exhaust requirements in the pump-limiter and the divertor cases. Also, high neutral recycling on the front surface of the limiter tends to increase the neutral pumping rate

Etching of Niobium in an Argon-Chlorine Capacitively Coupled Plasma

Science.gov (United States)

Radovanov, Svetlana; Samolov, Ana; Upadhyay, Janardan; Peshl, Jeremy; Popovic, Svetozar; Vuskovic, Leposava; Applied Materials, Varian Semiconductor Team; Old Dominion University Team

2016-09-01

Ion assisted etching of the inner surfaces of Nb superconducting radio frequency (SRF) cavities requires control of incident ion energies and fluxes to achieve the desired etch rate and smooth surfaces. In this paper, we combine numerical simulation and experiment to investigate Ar /Cl2 capacitively coupled plasma (CCP) in cylindrical reactor geometry. Plasma simulations were done in the CRTRS 2D/3D code that self-consistently solves for CCP power deposition and electrostatic potential. The experimental results are used in combination with simulation predictions to understand the dependence of plasma parameters on the operating conditions. Using the model we were able to determine the ion current and flux at the Nb substrate. Our simulations indicate the relative importance of the current voltage phase shift and displacement current at different pressures and powers. For simulation and the experiment we have used a test structure with a pillbox cavity filled with niobium ring-type samples. The etch rate of these samples was measured. The probe measurements were combined with optical emission spectroscopy in pure Ar for validation of the model. The authors acknowledge Dr Shahid Rauf for developing the CRTRS code. Support DE-SC0014397.

The prognostic value of the suPARnosticTM ELISA assay in HIV-1 infected individuals is not affected by uPAR promoter polymorphisms

DEFF Research Database (Denmark)

Schneider, Uffe; Nielsen, Rikke; Pedersen, Court

2007-01-01

. METHODS: DNA samples were collected retrospectively from 145 Danes infected with HIV-1 with known seroconversion times. In addition, plasma was collected retrospectively from 81 of these participants for use in the suPAR analysis. Survival was analysed using Kaplan Meier analysis. RESULTS: Survival...... to A transition at -118 and an A to G transition at -465 comparative to the transcription start site. These promoter transitions did not influence neither the suPAR levels nor patient survival. CONCLUSION: Plasma suPAR levels, as measured by the suPARnosticTM assay, were strongly predictive of survival in ART...

Review of inductively coupled plasmas: Nano-applications and bistable hysteresis physics

Science.gov (United States)

Lee, Hyo-Chang

2018-03-01

Many different gas discharges and plasmas exhibit bistable states under a given set of conditions, and the history-dependent hysteresis that is manifested by intensive quantities of the system upon variation of an external parameter has been observed in inductively coupled plasmas (ICPs). When the external parameters (such as discharge powers) increase, the plasma density increases suddenly from a low- to high-density mode, whereas decreasing the power maintains the plasma in a relatively high-density mode, resulting in significant hysteresis. To date, a comprehensive description of plasma hysteresis and a physical understanding of the main mechanism underlying their bistability remain elusive, despite many experimental observations of plasma bistability conducted under radio-frequency ICP excitation. This fundamental understanding of mode transitions and hysteresis is essential and highly important in various applied fields owing to the widespread use of ICPs, such as semiconductor/display/solar-cell processing (etching, deposition, and ashing), wireless light lamp, nanostructure fabrication, nuclear-fusion operation, spacecraft propulsion, gas reformation, and the removal of hazardous gases and materials. If, in such applications, plasma undergoes a mode transition and hysteresis occurs in response to external perturbations, the process result will be strongly affected. Due to these reasons, this paper comprehensively reviews both the current knowledge in the context of the various applied fields and the global understanding of the bistability and hysteresis physics in the ICPs. At first, the basic understanding of the ICP is given. After that, applications of ICPs to various applied fields of nano/environmental/energy-science are introduced. Finally, the mode transition and hysteresis in ICPs are studied in detail. This study will show the fundamental understanding of hysteresis physics in plasmas and give open possibilities for applications to various applied

Fast quantification of endogenous carbohydrates in plasma using hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry.

Science.gov (United States)

Zhu, Bangjie; Liu, Feng; Li, Xituo; Wang, Yan; Gu, Xue; Dai, Jieyu; Wang, Guiming; Cheng, Yu; Yan, Chao

2015-01-01

Endogenous carbohydrates in biosamples are frequently highlighted as the most differential metabolites in many metabolomics studies. A simple, fast, simultaneous quantitative method for 16 endogenous carbohydrates in plasma has been developed using hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry. In order to quantify 16 endogenous carbohydrates in plasma, various conditions, including columns, chromatographic conditions, mass spectrometry conditions, and plasma preparation methods, were investigated. Different conditions in this quantified analysis were performed and optimized. The reproducibility, precision, recovery, matrix effect, and stability of the method were verified. The results indicated that a methanol/acetonitrile (50:50, v/v) mixture could effectively and reproducibly precipitate rat plasma proteins. Cold organic solvents coupled with vortex for 1 min and incubated at -20°C for 20 min were the most optimal conditions for protein precipitation and extraction. The results, according to the linearity, recovery, precision, matrix effect, and stability, showed that the method was satisfactory in the quantification of endogenous carbohydrates in rat plasma. The quantified analysis of endogenous carbohydrates in rat plasma performed excellently in terms of sensitivity, high throughput, and simple sample preparation, which met the requirement of quantification in specific expanded metabolomic studies after the global metabolic profiling research. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

MODELISATION DE LA CINETIQUE CHIMIQUE DANS LA REDUCTION DES OXYDES D4AZOTE PAR DECHARGE COURONNE.

OpenAIRE

MEDJAHDI, Sarah ines

2015-01-01

CE TRAVAIL DE recherche rentre dans le cadre général de modélisation de la réduction des oxydes d'azote . l'utilisation des réacteurs a plasma froid non-thermique généré par des décharges couronnes est actuellement l'une des techniques les puis promettre .ses pour la destruction des oxydes d'azote .en effet , le traitement des gaz pollués par les décharges couronnes est notamment rendu possible par la multiplication des décharges Électriques .

A comprehensive study of different gases in inductively coupled plasma torch operating at one atmosphere

International Nuclear Information System (INIS)

Punjabi, Sangeeta B.; Joshi, N. K.; Mangalvedekar, H. A.; Lande, B. K.; Das, A. K.; Kothari, D. C.

2012-01-01

A numerical study is done to understand the possible operating regimes of RF-ICP torch (3 MHz, 50 kW) using different gases for plasma formation at atmospheric pressure. A two dimensional numerical simulation of RF-ICP torch using argon, nitrogen, oxygen, and air as plasma gas has been investigated using computational fluid dynamic (CFD) software fluent (c) . The operating parameters varied here are central gas flow, sheath gas flow, RF-power dissipated in plasma, and plasma gas. The temperature contours, flow field, axial, and radial velocity profiles were investigated under different operating conditions. The plasma resistance, inductance of the torch, and the heat distribution for various plasma gases have also been investigated. The plasma impedance of ICP torch varies with different operating parameters and plays an important role for RF oscillator design and power coupling. These studies will be useful to decide the design criteria for ICP torches required for different material processing applications.

In situ calibration of inductively coupled plasma-atomic emission and mass spectroscopy

Science.gov (United States)

Braymen, Steven D.

1996-06-11

A method and apparatus for in situ addition calibration of an inductively coupled plasma atomic emission spectrometer or mass spectrometer using a precision gas metering valve to introduce a volatile calibration gas of an element of interest directly into an aerosol particle stream. The present situ calibration technique is suitable for various remote, on-site sampling systems such as laser ablation or nebulization.

Plasma inhomogeneities near the electrodes of a capacitively-coupled radio-frequency discharge containing dust particles

Science.gov (United States)

Tawidian, H.; Mikikian, M.; Couëdel, L.; Lecas, T.

2011-11-01

Small plasma spheroids are evidenced and analyzed in front of the electrodes of a capacitively-coupled radio-frequency discharge in which dust particles are growing. These regions are characterized by a spherical shape, a slightly enhanced luminosity and are related to instabilities induced by the presence of dust particles. Several types of behaviors are identified and particularly their chaotic appearance or disappearance and their rotational motion along the electrode periphery. Correlations with the unstable behavior of the global plasma glow are performed. These analyses are obtained thanks to high-speed imaging which is the only diagnostics able to evidence these plasma spheroids.

Inductively coupled plasma as atomization, excitation and ionization sources in analytical atomic spectrometry

International Nuclear Information System (INIS)

Kawaguchi, Hiroshi

1996-01-01

Studies on inductively coupled plasma (ICP) for atomic emission and mass spectrometry accomplished in our laboratory since 1978 are reviewed. In emission spectrometry, the characteristics of the plasma are studied concerning the spatial profiles of spectral line intensity, axial profiles of gas and excitation temperatures, spectral line widths and matrix effect. The studies are particularly emphasized on the instrumentation such as developments of plasma generator, emission spectrometers, water-cooled torches and sample introduction methods. A slew-scan type spectrometer developed in these works represents a predecessor of the current commercial spectrometers. An ICP mass spectrometer was first developed in Japan in this laboratory in 1984. Non-spectroscopic interference of this method was found to have the correlation with the atomic weight of the matrix element. Plasma gases other than argon such as nitrogen and oxygen were used for the ICP to evaluate their performance in mass spectrometry as for the sensitivity and interferences. (author). 63 refs

Spectroanalytical investigations on inductively coupled N2/Ar and Ar/Ar high frequency plasmas

International Nuclear Information System (INIS)

Malinowski, P.; Mazurkiewicz, M.; Nickel, H.

1981-03-01

In order to improve the detection limits of trace elements in corrosion products of metallic materials, the inductively coupled plasma excitation source (ICP) was applied for spectroscopic analysis. Besides optimizing the working conditions for the mentioned materials, the fundamental research clearing the excitation processes in ICP was carried out. Basicly, two plasma systems were investigated: the nitrogen cooled N 2 /Ar- and pure Ar/Ar-plasma. The computed detection limits for 8 chosen elements are between 0.1 and 50 μg ml -1 in both plasmas. The advantage of ion lines was clearly present; in N 2 /Ar-plasma it was larger than in Ar/Ar-plasma. The excitation temperatures measured with help of ArI, FeI and ZnI lines rise with increasing power and decreasing distance from the induction coil. The distribution of Zn excitation temperature in N 2 /Ar-plasma as well as the measured N + 2 rotational and CN vibrational temperatures indicate, that the toroidal structure of Ar/Ar-plasma is not analogue to the N 2 /Ar-plasma. The values of the various excitation temperatures (Ar, Fe, Zn) and the differences between the excitation, vibration, rotation and ionization temperatures (Tsub(i) > Tsub(n) = Tsub(vib) > Tsub(rot)) indicate an absence of thermal equilibrium in the concerned system. (orig.)

The inductively coupled plasma as a source for the measurement of fundamental spectroscopic constants

International Nuclear Information System (INIS)

Farnsworth, P.B.

1993-01-01

Inductively coupled plasmas (ICPs) are stable, robust sources for the generation of spectra from neutral and singly ionized atoms. They are used extensively for analytical spectrometry, but have seen limited use for the measurement of fundamental spectroscopic constants. Several properties of the ICP affect its suitability for such fundamental measurements. They include: spatial structure, spectral background, noise characteristics, electron densities and temperatures, and the state of equilibrium in the plasma. These properties are particularly sensitive to the means by which foreign atoms are introduced into the plasma. With some departures from the operating procedures normally used in analytical measurements, the ICP promise to be a useful source for the measurement of fundamental atomic constants. (orig.)

Methods for detecting and correcting inaccurate results in inductively coupled plasma-atomic emission spectrometry

Science.gov (United States)

Chan, George C. Y. [Bloomington, IN; Hieftje, Gary M [Bloomington, IN

2010-08-03

A method for detecting and correcting inaccurate results in inductively coupled plasma-atomic emission spectrometry (ICP-AES). ICP-AES analysis is performed across a plurality of selected locations in the plasma on an unknown sample, collecting the light intensity at one or more selected wavelengths of one or more sought-for analytes, creating a first dataset. The first dataset is then calibrated with a calibration dataset creating a calibrated first dataset curve. If the calibrated first dataset curve has a variability along the location within the plasma for a selected wavelength, errors are present. Plasma-related errors are then corrected by diluting the unknown sample and performing the same ICP-AES analysis on the diluted unknown sample creating a calibrated second dataset curve (accounting for the dilution) for the one or more sought-for analytes. The cross-over point of the calibrated dataset curves yields the corrected value (free from plasma related errors) for each sought-for analyte.

Determination of trimethyllead reference material using high performance liquid chromatography-inductively coupled plasma mass spectrometry

International Nuclear Information System (INIS)

Lu Hai; Wei Chao; Wang Jun; Chao Jingbo; Zhou Tao; Chen Dazhou

2005-01-01

A high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICPMS) was combined, and the chromatography conditions were optimized. The stability and homogeneity of a trimethyllead reference material were determined using this method. (authors)

Analysis of zirconium alloys using inductively-coupled plasma emission spectrometry

International Nuclear Information System (INIS)

White, G.F.; Pickford, C.J.

1982-06-01

As part of an interlaboratory collaborative exercise, certain trace and minor elements have been determined in a proposed zircaloy reference material using inductively-coupled plasma emission spectrometry. A dissolution procedure involving hydrochloric and hydrofluoric acids was used for determination of Hf, Cr, Fe and Sn. Data have also been obtained for Ni, Cu and Mn. Use of a high resolution monochromator in a scanning mode was found necessary for measurement of the emission intensities in order to resolve the spectral lines of interest from the intense and complex emission from the zirconium matrix. (author)

X-ray spectroscopic characterization of laser produced hot dense plasmas; Caracterisation par spectroscopie X de plasmas chauds et denses crees par lasers de puissance

Energy Technology Data Exchange (ETDEWEB)

Kontogiannopoulos, N

2007-12-15

In this work we performed experiments of emission and absorption spectroscopy of laser produced plasmas, to provide well characterized spectral data which permit to benchmark atomic physics codes. More precisely, we produced xenon and krypton plasmas in NLTE (non local thermodynamic equilibrium) conditions and studied their emission spectra. In a second experiment, we characterized the absorption spectra of zinc sulfide and aluminium plasmas in LTE (local thermodynamic equilibrium) conditions.The first two chapters give an outline of the theory involved in the study of the emission and absorption plasma spectroscopy. Chapter 1 describes the different atomic processes occurring in a plasma. The LTE and the NLTE statistics ruling the equilibrium of the atomic processes are presented. Then, we give a brief description of the different codes of plasma atomic physics used in the analysis of our experimental data, namely HULLAC, SCO and TRANSPEC/AVERROES. In Chapter 2 the macroscopic theory of the radiation transport through a plasma is given. We describe also the self-similar model of Basko and the view factor approach, which permits us to calculate the heating conditions of the absorption foils achieved in the interior of the spherical gold cavity. Chapter 3 gives a description of the instruments used for realizing the two experiments, as well as the technical characteristics of the LULI2000 laser facility used to perform the experiments. Chapter 4 presents the experiment realized to characterize the emission spectra of the xenon and krypton plasmas in NLTE, as well the analysis of the experimental data with TRANSPEC/AVERROES. Finally, the experiment for measuring the absorption spectrum of the ZnS plasma mixture and the analysis of the experimental data with the code SCO are given in Chapter 5.

Magnetohydrodynamic stability of tokamak plasmas with poloidal mode coupling

International Nuclear Information System (INIS)

Shigueoka, H.; Sakanaka, P.H.

1987-01-01

The stability behavior with respect to internal modes is examined for a class of tokamak equilibria with non-circular cross sections. The surfaces of the constant poloidal magnetic flux ψ (R,Z) are obtained numerically by solving the Grad-Shafranov's equation with a specified shape for the outmost plasma surface. The equation of motion for ideal MHD stability is written in a ortogonal coordinate system (ψ, χ, φ). Th e stability analysis is performance numerically in a truncated set of coupled m (poloidal wave number) equations. The calculations involve no approximations, and so all parameters of the equilibrium solution can be arbitrarily varied. (author) [pt

Structure, function and expression on blood and bone marrow cells of the urokinase-type plasminogen activator receptor, uPAR

DEFF Research Database (Denmark)

Plesner, T; Behrendt, N; Ploug, M

1997-01-01

patients with the rare blood disease paroxysmal nocturnal hemoglobinuria (PNH) that fail to express glycosyl-phosphatidylinositol-anchored proteins including uPAR, show a very significantly reduced transmigration over an endothelial barrier. Cell-associated plasminogen activation by PNH......Several important functions have been assigned to the receptor for urokinase-type plasminogen activator, uPAR. As implied by the name, uPAR was first identified as a high affinity cellular receptor for urokinase plasminogen activator (uPA). It mediates the binding of the zymogen, pro......-uPA, to the plasma membrane where trace amounts of plasmin will initiate a series of events referred to as "reciprocal zymogen activation" where plasmin converts pro-uPA to the active enzyme, uPA, which in turn converts plasma membrane-associated plasminogen to plasmin. This is an efficient machinery to generate...

Plasma inhomogeneities near the electrodes of a capacitively-coupled radio-frequency discharge containing dust particles

International Nuclear Information System (INIS)

Tawidian, H; Mikikian, M.; Couedel, L.; Lecas, T.

2011-01-01

Dusty plasmas can be found in fusion devices. In this paper we analyse a new phenomenon occurring during dust particle growth instabilities and consisting of the appearance of small plasma spheroids in the vicinity of discharge electrodes. Small plasma spheroids are evidenced and analyzed in front of the electrodes of a capacitively-coupled radio-frequency discharge in which dust particles are growing. These regions are characterized by a spherical shape, a slightly enhanced luminosity and are related to instabilities induced by the presence of dust particles. Several types of behaviors are identified and particularly their chaotic appearance or disappearance and their rotational motion along the electrode periphery. Correlations with the unstable behavior of the global plasma glow are performed. These analyses are obtained thanks to high-speed imaging which is the only diagnostics able to evidence these plasma spheroids

Inductively coupled plasma-mass spectrometry: an initial assessment of the VG isotopes Plasmaquad

International Nuclear Information System (INIS)

Brown, R.M.; Pickford, C.J.

1985-04-01

The Chemical Analysis Group has been approached by a British Scientific instrument maker regarding the possibility of the group participating in a Department of Trade and Industry sponsored scheme whereby we would have a 12 month period to assess the advantages and disadvantages of a new analytical technique, Inductively Coupled Plasma-Mass Spectrometry. This report details our initial assessment of the instrument, carried out in order to decide whether to participate in the scheme. We have attempted to discover whether the instrument meets the claims made of it in advertising literature, and have attempted to compare the technique with another, proven technique, Inductively Coupled Plasma - Optical Emission Spectroscopy. The Plasmaquad offers excellent sensitivity for almost all of the elements of the periodic table, giving a distinct improvement over the Chemical Analysis Group's present capabilities for many elements. The isotope ratio measuring ability is important, as the Group has no such capability at the moment and a demand for this type of measurement is foreseen. Our conclusions, while inevitably somewhat subjective, form the basis for recommending Harwell to participate in the scheme. (author)

The effect of hydrogen on B4C coatings fabrication in inductively coupled plasma torch

Directory of Open Access Journals (Sweden)

Q. J. Guo

2018-02-01

Full Text Available Boron carbide (B4C coatings are prepared by an RF inductively coupled plasma (ICP torch with different amounts of hydrogen introduced into the sheath gas. The effects of the added hydrogen on the characteristics of the plasma are diagnosed by optical emission spectroscopy and high speed photography. The effects on the melting of B4C particles in the plasma are studied by scanning electron microscopy (SEM. The microstructure of the B4C coatings was determined with SEM imaging and x-ray diffraction analysis. The results show that adding hydrogen to the sheath gas leads to plasma contraction, which results in higher gas temperature of plasma. It also enhances B4C particles spheroidizing and improves the compactness of B4C coatings. Plasma processing does not change the main phase of boron carbide. The obtained results on B4C coatings on Cu substrates allows for improving the B4C coatings fabrication process.

Determination of the physical values of a plasma puff by analysis of the diamagnetic signals. 1. part: expansion model for the puff. 2. part: comparison of experimental results with the expansion model for the plasma puff; Determination des grandeurs physiques d'une bouffee de plasma par l'analyse de signaux diamagnetiques. 1. partie: modele d'expansion de bouffee. 2. partie: confrontation des resultats experimentaux et du modele d'expansion de la bouffee de plasma

Energy Technology Data Exchange (ETDEWEB)

Jacquinot, J; Leloup, Ch; Waelbroeck, F; Poffe, J P [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1964-07-01

The flow of a dense plasma puff, along the axis of a uniform magnetic field is examined, assuming the following hypotheses: the axial distribution of the line density can be described at any time by a gaussian function whose characteristic parameter is independent of the distance from the axis of the system; the {beta} ratio is less than 0,6. An approximate solution of the magnetohydrodynamics equations is obtained. The evolution of the characteristic properties of the plasma (local velocity, temperature and density) can be calculated from a set of equations involving 5 plasma parameters. A method leading to the determination of these parameters is described. It uses 5 informations picked up from the diamagnetic signals induced by the plasma into a set of 4 compensated magnetic loops. (authors) [French] L'ecoulement d'une bouffee dense de plasma le long des lignes de force d'un champ magnetique uniforme est etudie en faisant les hypotheses suivantes : la distribution axiale de la densite lineique est, a chaque instant, une gaussienne dont le parametre caracteristique ne depend pas de la distance a l'axe de revolution du systeme; {beta}(2 {mu}{sub 0} p/B{sup 2}{sub e}) est inferieur a 0,6. Dans ces conditions, une solution approchee des equations magneto-hydrodynamiques a pu etre trouvee. L'evolution des quantites physiques du plasma (vitesse, temperature, densite locale) est alors explicitement donnee par des equations dependant de 5 parametres. On decrit une methode permettant la determination de ces parametres. Elle necessite 5 informations prises sur les signaux diamagnetiques induits par le plasma dans un jeu de quatre boucles magnetiques compensees. (auteurs)

About the EDF formation in a capacitively coupled argon plasma

International Nuclear Information System (INIS)

Tatanova, M; Thieme, G; Basner, R; Hannemann, M; Golubovskii, Yu B; Kersten, H

2006-01-01

The formation of the electron distribution function (EDF) in the bulk plasma of a capacitively coupled radio-frequency (rf) discharge in argon generated in the plasma-chemical reactor PULVA-INP is investigated experimentally and theoretically. Measurements of the EDF and internal plasma parameters were performed by means of a Langmuir probe at pressures of 0.5-100 Pa and discharge powers of 5-100 W. The observed EDFs have revealed a two-temperature behaviour at low pressures and evolved into a Maxwellian distribution at high gas pressures and large discharge powers. Theoretical determination of the EDF is based on the numerical solution of the Boltzmann kinetic equation in the local and non-local approaches under experimental conditions. The model includes elastic and inelastic electron-atom collisions and electron-electron interactions. Low electron temperatures and relatively high ionization degrees are the features of the PULVA-INP rf discharge. This leads to significant influence of the electron-electron collisions on the EDF formation. The modelled and measured distributions show good agreement in a wide range of discharge parameters, except for a range of low gas pressures, where the stochastic electron heating is intense. Additionally, mechanisms of the EDF formation in the dc and rf discharge were compared under similar discharge conditions

About the EDF formation in a capacitively coupled argon plasma

Energy Technology Data Exchange (ETDEWEB)

Tatanova, M [Institute of Physics, Saint-Petersburg State University, ul. Ulianovskaja 1, 198504 Saint-Petersburg (Russian Federation); Thieme, G [Institut fur Niedertemperatur-Plasmaphysik, Friedrich-Ludwig-Jahn-Str 19, D-17489 Greifswald (Germany); Basner, R [Institut fur Niedertemperatur-Plasmaphysik, Friedrich-Ludwig-Jahn-Str 19, D-17489 Greifswald (Germany); Hannemann, M [Institut fur Niedertemperatur-Plasmaphysik, Friedrich-Ludwig-Jahn-Str 19, D-17489 Greifswald (Germany); Golubovskii, Yu B [Institute of Physics, Saint-Petersburg State University, ul. Ulianovskaja 1, 198504 Saint-Petersburg (Russian Federation); Kersten, H [Institut fur Niedertemperatur-Plasmaphysik, Friedrich-Ludwig-Jahn-Str 19, D-17489 Greifswald (Germany)

2006-08-01

The formation of the electron distribution function (EDF) in the bulk plasma of a capacitively coupled radio-frequency (rf) discharge in argon generated in the plasma-chemical reactor PULVA-INP is investigated experimentally and theoretically. Measurements of the EDF and internal plasma parameters were performed by means of a Langmuir probe at pressures of 0.5-100 Pa and discharge powers of 5-100 W. The observed EDFs have revealed a two-temperature behaviour at low pressures and evolved into a Maxwellian distribution at high gas pressures and large discharge powers. Theoretical determination of the EDF is based on the numerical solution of the Boltzmann kinetic equation in the local and non-local approaches under experimental conditions. The model includes elastic and inelastic electron-atom collisions and electron-electron interactions. Low electron temperatures and relatively high ionization degrees are the features of the PULVA-INP rf discharge. This leads to significant influence of the electron-electron collisions on the EDF formation. The modelled and measured distributions show good agreement in a wide range of discharge parameters, except for a range of low gas pressures, where the stochastic electron heating is intense. Additionally, mechanisms of the EDF formation in the dc and rf discharge were compared under similar discharge conditions.

Surface characterization of hydrophobic thin films deposited by inductively coupled and pulsed plasmas

International Nuclear Information System (INIS)

Kim, Youngsoo; Lee, Ji-Hye; Kim, Kang-Jin; Lee, Yeonhee

2009-01-01

Different fluorocarbon thin films were deposited on Si substrates using a plasma-polymerization method. Fluorine-containing hydrophobic thin films were obtained by inductively coupled plasma (ICP) and pulsed plasma (PP) with a mixture of fluorocarbon precursors C 2 F 6 , C 3 F 8 , and c-C 4 F 8 and the unsaturated hydrocarbons of C 2 H 2 . The influence on the fluorocarbon surfaces of the process parameters for plasma polymerization, including the gas ratio and the plasma power, were investigated under two plasma-polymerized techniques with different fluorocarbon gas precursors. The hydrophobic properties, surface morphologies, and chemical compositions were elucidated using water contact angle measurements, field emission-scanning electron microscope, x-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), and time-of-flight secondary ion mass spectrometry (TOF-SIMS). In this study, the ICP technique provides coarser grained films and more hydrophobic surfaces as well as a higher deposition rate compared to the PP technique. XPS, FT-IR, and TOF-SIMS analyses indicated that the ICP technique produced more fluorine-related functional groups, including CF 2 and CF 3 , on the surface. From the curve-fitted XPS results, fluorocarbon films grown under ICP technique exhibited less degree of cross-linking and higher CF 2 concentrations than those grown under PP technique.

Bifurcation analysis for ion acoustic waves in a strongly coupled plasma including trapped electrons

Science.gov (United States)

El-Labany, S. K.; El-Taibany, W. F.; Atteya, A.

2018-02-01

The nonlinear ion acoustic wave propagation in a strongly coupled plasma composed of ions and trapped electrons has been investigated. The reductive perturbation method is employed to derive a modified Korteweg-de Vries-Burgers (mKdV-Burgers) equation. To solve this equation in case of dissipative system, the tangent hyperbolic method is used, and a shock wave solution is obtained. Numerical investigations show that, the ion acoustic waves are significantly modified by the effect of polarization force, the trapped electrons and the viscosity coefficients. Applying the bifurcation theory to the dynamical system of the derived mKdV-Burgers equation, the phase portraits of the traveling wave solutions of both of dissipative and non-dissipative systems are analyzed. The present results could be helpful for a better understanding of the waves nonlinear propagation in a strongly coupled plasma, which can be produced by photoionizing laser-cooled and trapped electrons [1], and also in neutron stars or white dwarfs interior.

An evaluation of inductively coupled plasma optical emission spectrometry using electrothermal atomisation sample introduction and photographic plate detection

International Nuclear Information System (INIS)

Khathing, D.T.; Pickford, C.J.

1984-05-01

A photographic radiation measurement approach has been used with an inductively coupled plasma source to evaluate and tabulate the more prominent optical emission lines of 66 elements. Compared with the more common sample introduction technique using nebulisation, increased sensitivity for multielement analysis of small samples was achieved by using a simple graphite electrothermal atomisation system. This was constructed to serve as a dual purpose atomiser ie both for Atomic Absorption and for Inductively Coupled Plasma Emission spectroscopy. The system offers the advantage of a wide multi-elemental coverage, but sensitivities achieved with photographic detection are poorer than those obtained photoelectrically. (author)

Inductively coupled plasma induced deep levels in epitaxial n-GaAs

Energy Technology Data Exchange (ETDEWEB)

Auret, F.D.; Janse van Rensburg, P.J.; Meyer, W.E.; Coelho, S.M.M. [Department of Physics, University of the Pretoria, Lynnwood Road, Pretoria 0002 (South Africa); Kolkovsky, Vl. [Technische Universitaet, Dresden, 01062 Dresden (Germany); Botha, J.R.; Nyamhere, C. [Department of Physics, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth 6031 (South Africa); Venter, A., E-mail: andre.venter@nmmu.ac.za [Department of Physics, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth 6031 (South Africa)

2012-05-15

The electronic properties of defects introduced by low energy inductively coupled Ar plasma etching of n-type (Si doped) GaAs were investigated by deep level transient spectroscopy (DLTS) and Laplace DLTS. Several prominent electron traps (E{sub c}-0.046 eV, E{sub c}-0.186 eV, E{sub c}-0.314 eV. E{sub c}-0.528 eV and E{sub c}-0.605 eV) were detected. The metastable defect E{sub c}-0.046 eV having a trap signature similar to E1 is observed for the first time. E{sub c}-0.314 eV and E{sub c}-0.605 eV are metastable and appear to be similar to the M3 and M4 defects present in dc H-plasma exposed GaAs.

Inductively coupled plasma induced deep levels in epitaxial n-GaAs

International Nuclear Information System (INIS)

Auret, F.D.; Janse van Rensburg, P.J.; Meyer, W.E.; Coelho, S.M.M.; Kolkovsky, Vl.; Botha, J.R.; Nyamhere, C.; Venter, A.

2012-01-01

The electronic properties of defects introduced by low energy inductively coupled Ar plasma etching of n-type (Si doped) GaAs were investigated by deep level transient spectroscopy (DLTS) and Laplace DLTS. Several prominent electron traps (E c —0.046 eV, E c —0.186 eV, E c —0.314 eV. E c —0.528 eV and E c —0.605 eV) were detected. The metastable defect E c —0.046 eV having a trap signature similar to E1 is observed for the first time. E c —0.314 eV and E c —0.605 eV are metastable and appear to be similar to the M3 and M4 defects present in dc H-plasma exposed GaAs.

Low-frequency, self-sustained oscillations in inductively coupled plasmas used for optical pumping

Energy Technology Data Exchange (ETDEWEB)

Coffer, J.; Encalada, N.; Huang, M.; Camparo, J. [Physical Sciences Laboratories, The Aerospace Corporation 2310, E. El Segundo Blvd., El Segundo, California 90245 (United States)

2014-10-28

We have investigated very low frequency, on the order of one hertz, self-pulsing in alkali-metal inductively-coupled plasmas (i.e., rf-discharge lamps). This self-pulsing has the potential to significantly vary signal-to-noise ratios and (via the ac-Stark shift) resonant frequencies in optically pumped atomic clocks and magnetometers (e.g., the atomic clocks now flying on GPS and Galileo global navigation system satellites). The phenomenon arises from a nonlinear interaction between the atomic physics of radiation trapping and the plasma's electrical nature. To explain the effect, we have developed an evaporation/condensation theory (EC theory) of the self-pulsing phenomenon.

Simulation of Main Plasma Parameters of a Cylindrical Asymmetric Capacitively Coupled Plasma Micro-Thruster using Computational Fluid Dynamics

Directory of Open Access Journals (Sweden)

Amelia eGreig

2015-01-01

Full Text Available Computational fluid dynamics (CFD simulations of a radio-frequency (13.56 MHz electro-thermal capacitively coupled plasma (CCP micro-thruster have been performed using the commercial CFD-ACE+ package. Standard operating conditions of a 10 W, 1.5 Torr argon discharge were used to compare with previously obtained experimental results for validation. Results show that the driving force behind plasma production within the thruster is ion-induced secondary electrons ejected from the surface of the discharge tube, accelerated through the sheath to electron temperatures up to 33.5 eV. The secondary electron coefficient was varied to determine the effect on the discharge, with results showing that full breakdown of the discharge did not occur for coefficients coefficients less than or equal to 0.01.

First-in-human uPAR PET: Imaging of Cancer Aggressiveness

Science.gov (United States)

Persson, Morten; Skovgaard, Dorthe; Brandt-Larsen, Malene; Christensen, Camilla; Madsen, Jacob; Nielsen, Carsten H.; Thurison, Tine; Klausen, Thomas Levin; Holm, Søren; Loft, Annika; Berthelsen, Anne Kiil; Ploug, Michael; Pappot, Helle; Brasso, Klaus; Kroman, Niels; Højgaard, Liselotte; Kjaer, Andreas

2015-01-01

A first-in-human clinical trial with Positron Emission Tomography (PET) imaging of the urokinase-type plasminogen activator receptor (uPAR) in patients with breast, prostate and bladder cancer, is described. uPAR is expressed in many types of human cancers and the expression is predictive of invasion, metastasis and indicates poor prognosis. uPAR PET imaging therefore holds promise to be a new and innovative method for improved cancer diagnosis, staging and individual risk stratification. The uPAR specific peptide AE105 was conjugated to the macrocyclic chelator DOTA and labeled with 64Cu for targeted molecular imaging with PET. The safety, pharmacokinetic, biodistribution profile and radiation dosimetry after a single intravenous dose of 64Cu-DOTA-AE105 were assessed by serial PET and computed tomography (CT) in 4 prostate, 3 breast and 3 bladder cancer patients. Safety assessment with laboratory blood screening tests was performed before and after PET ligand injection. In a subgroup of the patients, the in vivo stability of our targeted PET ligand was determined in collected blood and urine. No adverse or clinically detectable side effects in any of the 10 patients were found. The ligand exhibited good in vivo stability and fast clearance from plasma and tissue compartments by renal excretion. In addition, high uptake in both primary tumor lesions and lymph node metastases was seen and paralleled high uPAR expression in excised tumor tissue. Overall, this first-in-human study therefore provides promising evidence for safe use of 64Cu-DOTA-AE105 for uPAR PET imaging in cancer patients. PMID:26516369

Sum rule and hydrodynamic analyses of the velocity autocorrelation function in strongly coupled plasmas

International Nuclear Information System (INIS)

Nagano, Seido; Ichimaru, Setsuo

1980-01-01

The memory function for the velocity autocorrelation function in a strongly coupled, one-component plasma is analyzed in the short time and long time domains, respectively, with the aid of the frequency-moment sum rules and the hydrodynamic consideration evoking the idea of the generalized Stokes friction. A series of interpolation schemes with successively improved accuracies are then introduced. Numerical investigations of those interpolation schemes clarify the physical origin of the three different types of the velocity autocorrelation function observed in the molecular dynamics simulation at different regimes of the coupling constant. (author)

Inductively coupled plasma for atomic emission spectroscopy at the Savannah River Plant

International Nuclear Information System (INIS)

Coleman, J.T.

1986-01-01

The Savannah River Plant atomic emission spectroscopy laboratory has been in operation for over 30 years. Routine analytical methods and instrumentation are being replaced with current technology. Laboratory renovation will include the installation of contained dual excitation sources (inductively coupled plasma and d-c arc) with a direct reading spectrometer. The instrument will be used to provide impurity analyses of plutonium, uranium, and other nuclear fuel cycle materials

Phosphorus doped graphene by inductively coupled plasma and triphenylphosphine treatments

Energy Technology Data Exchange (ETDEWEB)

Shin, Dong-Wook, E-mail: shindong37@skku.edu; Kim, Tae Sung; Yoo, Ji-Beom, E-mail: jbyoo@skku.edu

2016-10-15

Highlights: • Substitution doping is a promising method for opening the energy band gap of graphene. • Substitution doping with phosphorus in the graphene lattice has numerous advantage such as high band gap, low formation energy, and high net charge density compared to nitrogen. • V{sub dirac} of Inductively coupled plasma (ICP) and triphenylphosphine (TPP) treated graphene was −57 V, which provided clear evidence of n-type doping. • Substitutional doping of graphene with phosphorus is verified by the XPS spectra of P 2p core level and EELS mapping of phosphorus. • The chemical bonding between P and graphene is very stable for a long time in air (2 months). - Abstract: Graphene is considered a host material for various applications in next-generation electronic devices. However, despite its excellent properties, one of the most important issues to be solved as an electronic material is the creation of an energy band gap. Substitution doping is a promising method for opening the energy band gap of graphene. Herein, we demonstrate the substitutional doping of graphene with phosphorus using inductively coupled plasma (ICP) and triphenylphosphine (TPP) treatments. The electrical transfer characteristics of the phosphorus doped graphene field effect transistor (GFET) have a V{sub dirac} of ∼ − 54 V. The chemical bonding between P and C was clearly observed in XPS spectra, and uniform distribution of phosphorus within graphene domains was confirmed by EELS mapping. The capability for substitutional doping of graphene with phosphorus can significantly promote the development of graphene based electronic devices.

Electron temperatures of inductively coupled Cl2-Ar plasmas

International Nuclear Information System (INIS)

Fuller, N.C.M.; Donnelly, Vincent M.; Herman, Irving P.

2002-01-01

Trace rare gases optical emission spectroscopy has been used to measure the electron temperature, T e , in a high-density inductively coupled Cl 2 -Ar plasma at 18 mTorr as function of the 13.56 MHz radio frequency power and Ar fraction. Only the Kr and Xe emission lines were used to determine T e , because of evidence of radiation trapping when the Ar emission lines were also used for larger Ar fractions. At 600 W (10.6 W cm-2), T e increases from ∼4.0±0.5 eV to ∼6.0±2.0 eV as the Ar fraction increases from 1% to 96%. In the H (inductive, bright) mode, T e , for a 'neat' chlorine plasma (including 1% of each He/Ne/Ar/Kr/Xe) increases only slightly from ∼3.8 to 4.0 eV as power increases from 450 to 750 W. This increase is much larger for larger Ar fractions, such as from ∼4.0 to 7.3 eV for 78% Ar. Most of these effects can be understood using the fundamental particle balance equation

Soluble urokinase-type plasminogen activator receptor forms in plasma as markers of atherosclerotic plaque vulnerability

DEFF Research Database (Denmark)

Olson, Fredrik J; Thurison, Tine; Ryndel, Mikael

2009-01-01

OBJECTIVES:: To test if circulating forms of the soluble urokinase-type plasminogen activator receptor (suPAR) are potential biomarkers of plaque vulnerability. DESIGN AND METHODS:: Plasma concentrations of suPAR(I-III), suPAR(II-III) and uPAR(I) were measured by time-resolved fluorescence immuno...

An argon–nitrogen–hydrogen mixed-gas plasma as a robust ionization source for inductively coupled plasma mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Makonnen, Yoseif; Beauchemin, Diane, E-mail: diane.beauchemin@chem.queensu.ca

2014-09-01

Multivariate optimization of an argon–nitrogen–hydrogen mixed-gas plasma for minimum matrix effects, while maintaining analyte sensitivity as much as possible, was carried out in inductively coupled plasma mass spectrometry. In the presence of 0.1 M Na, the 33.9 ± 3.9% (n = 13 elements) analyte signal suppression on average observed in an all-argon plasma was alleviated with the optimized mixed-gas plasma, the average being − 4.0 ± 8.8%, with enhancement in several cases. An addition of 2.3% v/v N{sub 2} in the outer plasma gas, and 0.50% v/v H{sub 2} to the central channel, as a sheath around the nebulizer gas flow, was sufficient for this drastic increase in robustness. It also reduced the background from ArO{sup +} and Ar{sub 2}{sup +} as well as oxide levels by over an order of magnitude. On the other hand, the background from NO{sup +} and ArN{sup +} increased by up to an order of magnitude while the levels of doubly-charged ions increased to 7% (versus 2.7% in an argon plasma optimized for sensitivity). Furthermore, detection limits were generally degraded by 5 to 15 fold when using the mixed-gas plasma versus the argon plasma for matrix-free solution (although they were better for several elements in 0.1 M Na). Nonetheless, the drastically increased robustness allowed the direct quantitative multielement analysis of certified ore reference materials, as well as the determination of Mo and Cd in seawater, without using any matrix-matching or internal standardization. - Highlights: • Addition of N{sub 2} to the plasma gas and H{sub 2} as a sheath gas results in a very robust ICP. • ArO{sup +} and Ar{sub 2}{sup +} background and oxide levels are reduced by over an order of magnitude. • Multielement analysis of rock digests is possible with a simple external calibration. • No internal standardization or matrix-matching is required for accurate analysis. • Cd and Mo were accurately determined in undiluted seawater.

Quantum Simulations of Strongly Coupled Quark-Gluon Plasma

International Nuclear Information System (INIS)

Filinov, V.S.; Bonitz, M.; Ivanov, Yu.B.

2013-01-01

particles. This method has been successfully applied to strongly coupled electrodynamic plasmas (EMP). A strongly correlated behavior of the QGP is expected to show up in long-ranged spatial correlations of quarks and gluons which, in fact, may give rise to liquid-like and, possibly, solid-like structures. This expectation is based on a very similar behavior observed in electrodynamic plasmas. We have done already the first calculation of the QGP equation of state, spatial and color pair distribution functions, diffusion coefficients and shear viscosity. The preliminary results has already been reported and discussed at the international conferences and meetings and are accepted for publications. (author)

Serum tetranectin is an independent prognostic marker in colorectal cancer and weakly correlated with plasma suPAR, plasma PAI-1 and serum CEA

DEFF Research Database (Denmark)

Høgdall, Claus K; Christensen, Ib J; Stephens, Ross W

2002-01-01

PAR and CEA had a 2.43 increased risk as compared to a patient with median levels of these biochemical markers. Significant correlations were found with Dukes' stages for all the biochemical markers and between the respective biochemical markers. The findings confirm that TN is a strong prognostic factor...... activator (uPAR) and carcinoembryonic antigen (CEA). Significantly shorter survival was found for patients with TN levels below a cut-off point of 7.5 mg/l compared to patients with levels above, as illustrated by Kaplan-Meier curves. By Cox analyses, log TN, log soluble uPAR as well as log CEA were found...... to have an independent prognostic value for survival (log TN: HR = 0.47, 95% CI: 0.29-0.76); log soluble uPAR: HR = 1.65, 95% CI: 1.18-2.31; log CEA: HR = 1.I1, 95% CI: 1.03-1.20). Based on the multivariate model, a patient with a combination of low levels of TN and PAI-1 and elevated levels of soluble u...

Convergent-close-coupling calculations for excitation and ionization processes of electron-hydrogen collisions in Debye plasmas

International Nuclear Information System (INIS)

Zammit, Mark C.; Fursa, Dmitry V.; Bray, Igor

2010-01-01

Electron-hydrogen scattering in weakly coupled hot-dense plasmas has been investigated using the convergent-close-coupling method. The Yukawa-type Debye-Hueckel potential has been used to describe the plasma screening effects. The target structure, excitation dynamics, and ionization process change dramatically as the screening is increased. Excitation cross sections for the 1s→2s,2p,3s,3p,3d and 2s→2p,3s,3p,3d transitions and total and total ionization cross sections for the scattering from the 1s and 2s states are presented. Calculations cover the energy range from thresholds to high energies (250 eV) for various Debye lengths. We find that as the screening increases, the excitation and total cross sections decrease, while the total ionization cross sections increase.

Matrix digestion of soil and sediment samples for extraction of lead, cadmium and antimony and their direct determination by inductively coupled plasma-mass spectrometry and atomic emission spectrometry

International Nuclear Information System (INIS)

Chattopadhyay, P.; Fisher, A.S.; Henon, D.N.; Hill, S.J.

2004-01-01

An environmentally friendly and simple method has been developed for complete digestion of lead, cadmium and antimony from soil samples using a magnesium nitrate assisted dry ashing procedure. Statistical data for a series of experiments with standard reference materials are presented, and precision values are found to be comparable for inductively coupled plasma-mass spectrometry and for inductively coupled plasma-atomic emission spectrometry. From a single digest solution all analytes are quantified without involving any preconcentration routes. Inter-method comparison of inductively coupled plasma-mass spectrometry (ICP-MS) and inductively coupled plasma-atomic emission spectrometry (ICP-AES) shows that the probability of the results being different is less than 99 %. (author)

Concentration of vanadium in crude oil and water using inductively-coupled plasma spectrometry

International Nuclear Information System (INIS)

Amin, Y.M.; Hassan, M.A.; Junkin, K.; Mahat, R.H.; Raphie, B.

1991-01-01

Vanadium is a trace element that is usually associated to crude oil and its products. In this study the concentration of vanadium in a few samples of local crude oil, sea and river water were determined using inductively-coupled plasma spectrometry (ICP). It is hoped that the concentration of vanadium in water can be used to indicate the possible extent of oil contamination

Inductively coupled plasma etching of III-V antimonides in BCl3/SiCl4 etch chemistry

International Nuclear Information System (INIS)

Swaminathan, K.; Janardhanan, P.E.; Sulima, O.V.

2008-01-01

Inductively coupled plasma etching of GaSb using BCl 3 /SiCl 4 etch chemistry has been investigated. The etch rates were studied as a function of bias power, inductively coupled plasma source power, plasma chemistry and chamber pressure. The etched surfaces remain smooth and stoichiometric over the entire range of plasma conditions investigated. The knowledge gained in etching GaSb was applied to etching AlGaAsSb and InGaAsSb in order to fabricate heterojunction phototransistors. As expected, InGaAsSb etch rate was much lower compared to the corresponding value for GaSb, mainly due to the relatively low volatility of indium chlorides. For a wide range of plasma conditions, the selectivity between GaSb and AlGaAsSb was close to unity, which is desirable for fabricating etched mirrors and gratings for Sb-based mid-infrared laser diodes. The surface roughness and the etch profile were examined for the etched GaSb, AlGaAsSb and InGaAsSb samples using scanning electron microscope. The high etch rates achieved (∼ 4 μm/min) facilitated deep etching of GaSb. A single layer, soft mask (AZ-4903 photoresist) was used to etch GaSb, with etch depth ∼ 90 μm. The deep dry etching of GaSb has many important applications including etching substrate windows for backside-illuminated photodetectors for the mid-infrared wavelength range

Propagation and diffusion of a plasma column in a magnetic field; Propagation et diffusion d'une colonne de plasma dans un champ magnetique

Energy Technology Data Exchange (ETDEWEB)

Bottiglioni, F; Coutant, J; Gadda, E; Prevot, F [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1966-12-01

A plasma column is created in a magnetic field by longitudinal diffusion from a low-pressure pulsed discharge in hydrogen. Depending on the discharge conditions, two regimes are obtained in which the gas pumping speed has a different effect upon the plasma density in the column. Calculations are presented which can explain this effect by a difference in the transverse diffusion coefficient. (authors) [French] On forme une colonne de plasma dans un champ magnetique par diffusion longitudinale a partir d'une decharge puisee dans l'hydrogene a basse pression. Selon les conditions de la decharge on observe deux regimes differents pour lesquels le pompage du gaz neutre a un effet different sur la densite resultante du plasma dans la colonne. On presente des calculs qui peuvent expliquer cet effet par une difference dans la diffusion transversale du plasma. (auteurs)

Drag force in strongly coupled, anisotropic plasma at finite chemical potential

Energy Technology Data Exchange (ETDEWEB)

Chakraborty, Somdeb; Haque, Najmul [Theory Division, Saha Institute of Nuclear Physics,1/AF Bidhannagar, Kolkata-700 064 (India)

2014-12-30

We employ methods of gauge/string duality to analyze the drag force on a heavy quark moving through a strongly coupled, anisotropic N=4,SU(N) super Yang-Mills plasma in the presence of a finite U(1) chemical potential. We present numerical results valid for any value of the anisotropy parameter and the U(1) charge density and arbitrary direction of the quark velocity with respect to the direction of anisotropy. In the small anisotropy limit we are also able to furnish analytical results.

Determination of hafnium at the 10−4% level (relative to zirconium content) using neutron activation analysis, inductively coupled plasma mass spectrometry and inductively coupled plasma atomic emission spectrometry

International Nuclear Information System (INIS)

Smolik, Marek; Polkowska-Motrenko, Halina; Hubicki, Zbigniew; Jakóbik-Kolon, Agata; Danko, Bożena

2014-01-01

Graphical abstract: -- Highlights: •We worked out ICP-MS method of Hf determination in Zr and Zr compounds. •We used NAA method as reference one. •We obtained pure zirconium matrix by ion exchange (Diphonix ® resin). •These permit to determine ≥1 × 10 −4 % Hf in Zr sample by ICP MS with good precision and accuracy. -- Abstract: Hafnium at the very low level of 1–8 ppm (in relation to zirconium) was determined in zirconium sulfate solutions (originating from investigations of the separation of ca. 44 ppm Hf from zirconium by means of the ion exchange method) by using three independent methods: inductively coupled plasma mass spectrometry (ICP MS), neutron activation analysis (NAA) and inductively coupled plasma atomic emission spectrometry (ICP-AES). The results of NAA and ICP MS determinations were consistent with each other across the entire investigated range (the RSD of both methods did not exceed 38%). The results of ICP-AES determination were more diverse, particularly at less than 5 ppm Hf (RSD was significantly higher: 29–253%). The ion exchange method exploiting Diphonix ® resin proved sufficient efficiency in Zr–Hf separation when the initial concentration ratio of the elements ([Zr] 0 /[Hf] 0 ) ranged from 1200 to ca. 143,000

Cell Adhesion to Plasma-Coated PVC

Directory of Open Access Journals (Sweden)

Elidiane C. Rangel

2014-01-01

Full Text Available To produce environments suitable for cell culture, thin polymer films were deposited onto commercial PVC plates from radiofrequency acetylene-argon plasmas. The proportion of argon in the plasmas, PAr, was varied from 5.3 to 65.8%. The adhesion and growth of Vero cells on the coated surfaces were examined for different incubation times. Cytotoxicity tests were performed using spectroscopic methods. Carbon, O, and N were detected in all the samples using XPS. Roughness remained almost unchanged in the samples prepared with 5.3 and 28.9% but tended to increase for the films deposited with PAr between 28.9 and 55.3%. Surface free energy increased with increasing PAr, except for the sample prepared at 28.9% of Ar, which presented the least reactive surface. Cells proliferated on all the samples, including the bare PVC. Independently of the deposition condition there was no evidence of cytotoxicity, indicating the viability of such coatings for designing biocompatible devices.

Strongly coupled semiclassical plasma: interaction model and some properties

International Nuclear Information System (INIS)

Baimbetov, N.F.; Bekenov, N.A.

1999-01-01

In the report a fully ionized strongly coupled hydrogen plasma is considered. The density number is considered within range n=n e =n i ≅(10 21 -2·10 25 )sm -3 , and the temperature domian is T≅(5·10 4 -10 6 ) K. The coupling parameter Γ is defined by Γ=e 2 /αk B T, where k B is the Boltzmann constant and e is electrical charge, α=(3/4πn) 1/3 is the average distance between the particles (Wigner-Seitz radius). The dimensionless density parameter r s =α/α B is given in terms of the Bohr radius α B =ℎ 2 /me 2 ∼0.529·10 - 8 sm. The degeneracy parameter for the electron was defined by the ratio between the thermal energy k B T and the Fermi energy E F :Θ=k B T/E F ∼0.54·r s /Γ. The intermediate temperature-density region, where Γ≥1; Θ≅1; T>13.6 eV is examined. A semiclassical effective potential which account for the short-range, quantum diffraction and symmetry effects of charge carriers screening

Determination of selenoprotein P in human plasma by solid phase extraction and inductively coupled plasma mass spectrometry

DEFF Research Database (Denmark)

Bendahl, L.; Sidenius, U.; Gammelgaard, Bente

2000-01-01

measured by inductively coupled plasma mass spectrometry (ICP-MS) monitoring the Se-82 isotope. Linear response was observed in the concentration range 0.3-70.8 mu g/l selenium as selenoprotein P with a correlation coefficient of 0.9994. The precision expressed as relative standard deviation was better...... than 2% in this range. The estimated limit of detection was 2 mu g/l and the experimentally verified quantification limit was 5 mu g/l, giving a relative standard deviation less than 2%. (C) 2000 Elsevier Science B.V. All rights reserved...

Experimental characterization of a strongly coupled solid density plasma generated in a short-pulse laser target interaction

International Nuclear Information System (INIS)

Gregori, G.; Hansen, S.B.; Key, M.H.; King, J.; Mackinnon, A.J.; Park, H.; Patel, P.K.; Shepard, R.; Snavely, R.A.; Wilks, S.C.; Glenzer, S.H.

2005-01-01

We have measured high resolution copper Kα spectra from a picosecond high intensity laser produced plasma. By fitting the shape of the experimental spectra with a self-consistent-field model which includes all the relevant line shifts from multiply ionized atoms, we are able to infer time and spatially averaged electron temperatures (T e ) and ionization state (Z) in the foil. Our results show increasing values for T e and Z when the overall mass of the target is reduced. In particular, we measure temperatures in excess of 200 eV with Z ∼ 13-14. For these conditions the ion-ion coupling constant is Λ ii ∼ 8-9, thus suggesting the achievement of a strongly coupled plasma regime

Experimental characterization of a strongly coupled solid density plasma generated in a short-pulse laser target interaction

Energy Technology Data Exchange (ETDEWEB)

Gregori, G; Hansen, S B; Key, M H; King, J; Mackinnon, A J; Park, H; Patel, P K; Shepard, R; Snavely, R A; Wilks, S C; Glenzer, S H

2005-03-17

We have measured high resolution copper K{alpha} spectra from a picosecond high intensity laser produced plasma. By fitting the shape of the experimental spectra with a self-consistent-field model which includes all the relevant line shifts from multiply ionized atoms, we are able to infer time and spatially averaged electron temperatures (T{sub e}) and ionization state (Z) in the foil. Our results show increasing values for T{sub e} and Z when the overall mass of the target is reduced. In particular, we measure temperatures in excess of 200 eV with Z {approx} 13-14. For these conditions the ion-ion coupling constant is {Lambda}{sub ii} {approx} 8-9, thus suggesting the achievement of a strongly coupled plasma regime.

Development of inductively coupled plasma atomic emission spectrometry for palladium and Rhodium determination in platinum-based alloy

International Nuclear Information System (INIS)

Kovacevic, R.; Todorovic, M.; Manojlovic, D.; Mutic, J.

2008-01-01

Inductively coupled plasma atomic emission spectroscopy with internal standardization was applied for the analysis of an in-house reference platinum alloy containing palladium and rhodium (approximately 5% by weight). In order to compensate for variations in signal recovery due to matrix interferences, and therefore to improve the precision, platinum. the major component, was chosen as an internal standard. Quantitative analysis was based on calibration using a set of matrix-matched calibration standards with and without employing the internal standard. These results were compared with those obtained by X-ray fluorescence spectroscopy. The results for both techniques were in a good agreement, although the precision was slightly better in the inductively coupled plasma atomic emission spectroscopy technique, with or without the internal standard

Efficient coupling of 527 nm laser beam power to a long scale-length plasma

International Nuclear Information System (INIS)

Moody, J.D.; Divol, L.; Glenzer, S.H.; MacKinnon, A.J.; Froula, D.H.; Gregori, G.; Kruer, W.L.; Meezan, N.B.; Suter, L.J.; Williams, E.A.; Bahr, R.; Seka, W.

2006-01-01

We experimentally demonstrate that application of laser smoothing schemes including smoothing by spectral dispersion (SSD) and polarization smoothing (PS) increases the intensity range for efficient coupling of frequency doubled (527 nm) laser light to a long scale-length plasma with n e /n cr equals 0.14 and T e equals 2 keV. (authors)

On the coupling of fields and particles in accelerator and plasma physics

International Nuclear Information System (INIS)

Geloni, Gianluca; Kocharyan, Vitali; Saldin, Evgeni

2016-10-01

In accelerator and plasma physics it is generally accepted that there is no need to solve the dynamical equations for particles motion in manifestly covariant form, that is by using the coordinate-independent proper time to parameterize particle world-lines in space-time. In other words, in order to describe the dynamical processes in the laboratory frame there is no need to use the laws of relativistic kinematics. It is sufficient to take into account the relativistic dependence of the particles momentum on the velocity in the second Newton's law. Therefore, the coupling of fields and particles is based, on the one hand, on the use of result from particle dynamics treated according to Newton's laws in terms of the relativistic three-momentum and, on the other hand, on the use of Maxwell's equations in standard form. In previous papers we argued that this is a misconception. The purpose of this paper is to describe in detail how to calculate the coupling between fields and particles in a correct way and how to develop a new algorithm for a particle tracking code in agreement with the use of Maxwell's equations in their standard form. Advanced textbooks on classical electrodynamics correctly tell us that Maxwell's equations in standard form in the laboratory frame and charged particles are coupled by introducing particles trajectories as projections of particles world-lines onto coordinates of the laboratory frame and by subsequently using the laboratory time to parameterize the trajectory curves. For the first time we showed a difference between conventional and covariant particle tracking results in the laboratory frame. This essential point has never received attention in the physical community. Only the solution of the dynamical equations in covariant form gives the correct coupling between field equations in standard form and particles trajectories in the laboratory frame. We conclude that previous theoretical and simulation results in accelerator and plasma

On the coupling of fields and particles in accelerator and plasma physics

Energy Technology Data Exchange (ETDEWEB)

Geloni, Gianluca [European XFEL GmbH, Hamburg (Germany); Kocharyan, Vitali; Saldin, Evgeni [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

2016-10-15

In accelerator and plasma physics it is generally accepted that there is no need to solve the dynamical equations for particles motion in manifestly covariant form, that is by using the coordinate-independent proper time to parameterize particle world-lines in space-time. In other words, in order to describe the dynamical processes in the laboratory frame there is no need to use the laws of relativistic kinematics. It is sufficient to take into account the relativistic dependence of the particles momentum on the velocity in the second Newton's law. Therefore, the coupling of fields and particles is based, on the one hand, on the use of result from particle dynamics treated according to Newton's laws in terms of the relativistic three-momentum and, on the other hand, on the use of Maxwell's equations in standard form. In previous papers we argued that this is a misconception. The purpose of this paper is to describe in detail how to calculate the coupling between fields and particles in a correct way and how to develop a new algorithm for a particle tracking code in agreement with the use of Maxwell's equations in their standard form. Advanced textbooks on classical electrodynamics correctly tell us that Maxwell's equations in standard form in the laboratory frame and charged particles are coupled by introducing particles trajectories as projections of particles world-lines onto coordinates of the laboratory frame and by subsequently using the laboratory time to parameterize the trajectory curves. For the first time we showed a difference between conventional and covariant particle tracking results in the laboratory frame. This essential point has never received attention in the physical community. Only the solution of the dynamical equations in covariant form gives the correct coupling between field equations in standard form and particles trajectories in the laboratory frame. We conclude that previous theoretical and simulation results in

Relationship between the induction frequency and LTE in inductively coupled plasmas

International Nuclear Information System (INIS)

Mostaghimi, J.; Boulos, M.I.

1990-01-01

In this paper, the effect of the induction frequency on the local thermodynamic equilibrium (LTE) conditions in an inductively coupled plasma is investigated. Using generators with frequencies ranging from 5 to 56 MHz, a previous study investigated demonstrated the importance of this effect. Their measurements of the excitation temperatures of the iron atomic lines showed a sharp decrease in this temperature as a result of the increase in frequency. Another conclusion was that, all other parameters constant, increase in frequency will help the promotion of non-LTE effects

FooPar

DEFF Research Database (Denmark)

Hargreaves, F. P.; Merkle, D.

2013-01-01

We present FooPar, an extension for highly efficient Parallel Computing in the multi-paradigm programming language Scala. Scala offers concise and clean syntax and integrates functional programming features. Our framework FooPar combines these features with parallel computing techniques. Foo......, results based on a empirical analysis on two supercomputers are given. We achieve close-to-optimal performance wrt. theoretical peak performance. Based on this result we conclude that FooPar allows programmers to fully access Scalas design features without suffering from performance drops when compared...

Coupled ion acoustic and drift waves in magnetized superthermal electron-positron-ion plasmas

Energy Technology Data Exchange (ETDEWEB)

Adnan, Muhammad; Qamar, Anisa [Institute of Physics and Electronics, University of Peshawar, Peshawar 25000 (Pakistan); National Center for Physics, Quaid-i-Azam University Campus, Shahdra Valley Road, Islamabad 44000 (Pakistan); Mahmood, S. [National Center for Physics, Quaid-i-Azam University Campus, Shahdra Valley Road, Islamabad 44000 (Pakistan); Theoretical Physics Division, PINSTECH P.O. Nilore Islamabad 44000 (Pakistan); Physics Institute, Federal University of Rio Grande do Sul (UFRGS), 915051-970, Porto Alegre, RS (Brazil)

2014-09-15

Linear and nonlinear coupled drift-ion acoustic waves are investigated in a nonuniform magnetoplasma having kappa distributed electrons and positrons. In the linear regime, the role of kappa distribution and positron content on the dispersion relation has been highlighted; it is found that strong superthermality (low value of κ) and addition of positrons lowers the phase velocity via decreasing the fundamental scalelengths of the plasmas. In the nonlinear regime, first, coherent nonlinear structure in the form of dipoles and monopoles are obtained and the boundary conditions (boundedness) in the context of superthermality and positron concentrations are discussed. Second, in case of scalar nonlinearity, a Korteweg–de Vries-type equation is obtained, which admit solitary wave solution. It is found that both compressive and rarefactive solitons are formed in the present model. The present work may be useful to understand the low frequency electrostatic modes in inhomogeneous electron positron ion plasmas, which exist in astrophysical plasma situations such as those found in the pulsar magnetosphere.

Coupled ion acoustic and drift waves in magnetized superthermal electron-positron-ion plasmas

Science.gov (United States)

Adnan, Muhammad; Mahmood, S.; Qamar, Anisa

2014-09-01

Linear and nonlinear coupled drift-ion acoustic waves are investigated in a nonuniform magnetoplasma having kappa distributed electrons and positrons. In the linear regime, the role of kappa distribution and positron content on the dispersion relation has been highlighted; it is found that strong superthermality (low value of κ) and addition of positrons lowers the phase velocity via decreasing the fundamental scalelengths of the plasmas. In the nonlinear regime, first, coherent nonlinear structure in the form of dipoles and monopoles are obtained and the boundary conditions (boundedness) in the context of superthermality and positron concentrations are discussed. Second, in case of scalar nonlinearity, a Korteweg-de Vries-type equation is obtained, which admit solitary wave solution. It is found that both compressive and rarefactive solitons are formed in the present model. The present work may be useful to understand the low frequency electrostatic modes in inhomogeneous electron positron ion plasmas, which exist in astrophysical plasma situations such as those found in the pulsar magnetosphere.

Use of a Monte-Carlo method for studying the statistical distribution of electric fields around an ion in a one-component plasma; Etude, par une methode de Monte-Carlo de la repartition statistique des champs electriques au niveau d'un ion, dans un plasma a une composante

Energy Technology Data Exchange (ETDEWEB)

Rossignol-Guzzi, D [Commissariat a l' Energie Atomique, 94 - Limeil-Brevannes (France). Centre d' Etudes Nucleaires

1968-11-01

A Monte-Carlo simulation has been made of the equilibrium configurations taken by a plasma of equally charged punctual ions, immersed in a uniform neutralizing background of electrons. The statistical repartition of the electric field acting on one ion, needed to obtain Stark effect, was specially obtained. Comparison for dense plasmas, was made with the former works of Holtzmark, Mayer, Broyles. (author) [French] On simule sur ordinateur, suivant une methode de Monte-Carlo, les configurations prises a l'equilibre thermodynamique par un plasma d'ions ponctuels et de meme charge, places dans un milieu d'electrons uniformement distribues. On etudie, en particulier, la repartition statistique des champs electriques au niveau d'un ion, utilisee dans les calculs d'effets Stark. On compare, dans le cadre des plasmas denses, les resultats obtenus aux travaux precedents de Holtzmark, Mayer, Broyles. (auteur)

Study on the RF inductively coupled plasma spheroidization of refractory W and W-Ta alloy powders

Science.gov (United States)

Chenfan, YU; Xin, ZHOU; Dianzheng, WANG; Neuyen VAN, LINH; Wei, LIU

2018-01-01

Spherical powders with good flowability and high stacking density are mandatory for powder bed additive manufacturing. Nevertheless, the preparation of spherical refractory tungsten and tungsten alloy powders is a formidable task. In this paper, spherical refractory metal powders processed by high-energy stir ball milling and RF inductively coupled plasma were investigated. By utilizing the technical route, pure spherical tungsten powders were prepared successfully, the flowability increased from 10.7 s/50 g to 5.5 s/50 g and apparent density increased from 6.916 g cm-3 to 11.041 g cm-3. Alloying element tantalum can reduce the tendency to micro-crack during tungsten laser melting and rapid solidification process. Spherical W-6Ta (%wt) powders were prepared in this way, homogeneous dispersion of tantalum in a tungsten matrix occurred but a small amount of flake-like shape particles appeared after high-energy stir ball milling. The flake-like shape particles can hardly be spheroidized in subsequent RF inductively coupled plasma process, might result from the unique suspended state of flaky particles under complex electric and magnetic fields as well as plasma-particle heat exchange was different under various turbulence models. As a result, the flake-like shape particles cannot pass through the high-temperature area of thermal plasma torch and cannot be spheroidized properly.

Instability and dynamics of two nonlinearly coupled intense laser beams in a quantum plasma

International Nuclear Information System (INIS)

Wang Yunliang; Shukla, P. K.; Eliasson, B.

2013-01-01

We consider nonlinear interactions between two relativistically strong laser beams and a quantum plasma composed of degenerate electron fluids and immobile ions. The collective behavior of degenerate electrons is modeled by quantum hydrodynamic equations composed of the electron continuity, quantum electron momentum (QEM) equation, as well as the Poisson and Maxwell equations. The QEM equation accounts the quantum statistical electron pressure, the quantum electron recoil due to electron tunneling through the quantum Bohm potential, electron-exchange, and electron-correlation effects caused by electron spin, and relativistic ponderomotive forces (RPFs) of two circularly polarized electromagnetic (CPEM) beams. The dynamics of the latter are governed by nonlinear wave equations that include nonlinear currents arising from the relativistic electron mass increase in the CPEM wave fields, as well as from the beating of the electron quiver velocity and electron density variations reinforced by the RPFs of the two CPEM waves. Furthermore, nonlinear electron density variations associated with the driven (by the RPFs) quantum electron plasma oscillations obey a coupled nonlinear Schrödinger and Poisson equations. The nonlinearly coupled equations for our purposes are then used to obtain a general dispersion relation (GDR) for studying the parametric instabilities and the localization of CPEM wave packets in a quantum plasma. Numerical analyses of the GDR reveal that the growth rate of a fastest growing parametrically unstable mode is in agreement with the result that has been deduced from numerical simulations of the governing nonlinear equations. Explicit numerical results for two-dimensional (2D) localized CPEM wave packets at nanoscales are also presented. Possible applications of our investigation to intense laser-solid density compressed plasma experiments are highlighted.

The effect of SF6 addition in a Cl2/Ar inductively coupled plasma for deep titanium etching

Science.gov (United States)

Laudrel, E.; Tillocher, T.; Meric, Y.; Lefaucheux, P.; Boutaud, B.; Dussart, R.

2018-05-01

Titanium is a material of interest for the biomedical field and more particularly for body implantable devices. Titanium deep etching by plasma was carried out in an inductively coupled plasma with a chlorine-based chemistry for the fabrication of titanium-based microdevices. Bulk titanium etch rate was first studied in Cl2/Ar plasma mixture versus the source power and the self-bias voltage. The plasma was characterized by Langmuir probe and by optical emission spectroscopy. The addition of SF6 in the plasma mixture was investigated. Titanium etch rate was optimized and reached a value of 2.4 µm · min-1. The nickel hard mask selectivity was also enhanced. The etched titanium surface roughness was reduced significantly.

Analysis of bauxite by inductively coupled plasma-atomic emission spectroscopy

Science.gov (United States)

Barnes, Ramon M.; Mahanti, Himansu S.

Methods are described for the analysis of bauxite by inductively coupled plasma (ICP) emission spectroscopy. Bauxite samples were dissolved either in HCl, HNO 3, and HF at 160°C in all-PTFE bomb or fused with NaOH. Spectral lines were selected after examination of experimental wavelength scans at each potential analyte wavelength. Limits of detection, background equivalent concentration, and analytical figures of merit were established. The accuracy of the method was confirmed by determining 17 elements in NBS-SRM bauxite samples. Silicon in HF solutions was analyzed using a modified ICP torch with a graphite injector tube, an inert nebulizer using PTFE capillary tubes, and a PTFE spray chamber.

Determination of rare earth elements in aluminum by inductively coupled plasma-atomic emission spectroscopy

International Nuclear Information System (INIS)

Mahanti, H.S.; Barnes, R.M.

1983-01-01

Inductively coupled plasma-atomic emission spectroscopy is evaluated for the determination of 14 rare earth elements in aluminum. Spectral line interference, limit of detection, and background equivalent concentration values are evaluated, and quantitative recovery is obtained from aluminum samples spiked with rare earth elements. The procedure is simple and suitable for routine process control analysis. 20 references, 5 tables

Experimental investigation of the Boltzmann relation for a bi-Maxwellian distribution in inductively coupled plasmas

International Nuclear Information System (INIS)

Bang, Jin Young; Chung, Chin Wook

2009-01-01

In plasma, the Boltzmann relation is often used to connect the electron density to the plasma potential because it is not easy to calculate electric potentials on the basis of the Poisson equation due to the quasineutrality. From the Boltzmann relation, the electric potential can be simply obtained from the electron density or vice versa. However, the Boltzmann relation assumes that electrons are in thermal equilibrium and have a Maxwellian distribution, so it cannot be applied to non-Maxwellian distributions. In this paper, the Boltzmann relation for bi-Maxwellian distributions was newly derived from fluid equations and the comparison with the experimental results was given by measuring electron energy probability functions in an inductively coupled plasma. It was found that the spatial distribution of the electron density in bulk plasma is governed by the effective electron temperature, while that of the cold and hot electrons are governed by each electron temperature.

Interleaflet Coupling, Pinning, and Leaflet Asymmetry—Major Players in Plasma Membrane Nanodomain Formation

Science.gov (United States)

Fujimoto, Toyoshi; Parmryd, Ingela

2017-01-01

The plasma membrane has a highly asymmetric distribution of lipids and contains dynamic nanodomains many of which are liquid entities surrounded by a second, slightly different, liquid environment. Contributing to the dynamics is a continuous repartitioning of components between the two types of liquids and transient links between lipids and proteins, both to extracellular matrix and cytoplasmic components, that temporarily pin membrane constituents. This make plasma membrane nanodomains exceptionally challenging to study and much of what is known about membrane domains has been deduced from studies on model membranes at equilibrium. However, living cells are by definition not at equilibrium and lipids are distributed asymmetrically with inositol phospholipids, phosphatidylethanolamines and phosphatidylserines confined mostly to the inner leaflet and glyco- and sphingolipids to the outer leaflet. Moreover, each phospholipid group encompasses a wealth of species with different acyl chain combinations whose lateral distribution is heterogeneous. It is becoming increasingly clear that asymmetry and pinning play important roles in plasma membrane nanodomain formation and coupling between the two lipid monolayers. How asymmetry, pinning, and interdigitation contribute to the plasma membrane organization is only beginning to be unraveled and here we discuss their roles and interdependence. PMID:28119914

Investigations on the pyrolysis of hydrocarbons in the inductive coupled RF-plasma and the deposited pyrocarbon

International Nuclear Information System (INIS)

Eisgruber, H.; Mazurkiewicz, M.; Nickel, H.

1979-08-01

The pyrocarbon coatings of the nuclear fuel particles for the High-Temperature Reactor (HTR) are produced by pyrolysis of hydrocarbons under high temperatures. The investigations of the inductive coupled argon or argon/hydrocarbon-plasma performed in the frame of this work deliver a contribution for the clarification of pyrolysis processes and the production of pyrolytic carbons in the plasma of an electric discharge. The argon-plasma, as high-temperature source, is diagnosed theoretically and emission-spectroscopically. To the pure argon-plasma the various hydrocarbons are added. Due to the thermal decomposition the carbon is separated in solid form. The structure of the deposited pyrocarbon is composed of different components. The depositions are characterised with the principles in use at the IRW and are assigned to the fluidized bed pyrocarbons as fas as possible. (orig.) [de

Sulfur analysis by inductively coupled plasma-mass spectrometry: A review

Energy Technology Data Exchange (ETDEWEB)

Giner Martínez-Sierra, J.; Galilea San Blas, O.; Marchante Gayón, J.M.; García Alonso, J.I., E-mail: jiga@uniovi.es

2015-06-01

In recent years the number of applications of sulfur (S) analysis using inductively coupled plasma mass spectrometry (ICP-MS) as detector has increased significantly. In this article we describe in some depth the application of ICP-MS for S analysis with emphasis placed on the sulfur-specific detection by hyphenated techniques such as LC, GC, CE and LA coupled on-line to ICP-MS. The different approaches available for sulfur isotope ratio measurements by ICP-MS are also detailed. Particular attention has been paid to the quantification of peptides/proteins and the analysis of metallopeptides/metalloproteins via sulfur by LC–ICP-MS. Likewise, the speciation analysis of metal-based pharmaceuticals and metallodrugs and non-metal selective detection of pharmaceuticals via S are highlighted. Labeling procedures for metabolic applications are also included. Finally, the measurement of natural variations in S isotope composition with multicollector ICP-MS instruments is also covered in this review. - Highlights: • Emphasis placed on the sulfur-specific detection by chromatographic techniques coupled on-line to ICP-MS. • Different instrumental approaches available for sulfur measurements by ICP-MS. • Quantification of proteins and the analysis of metalloproteins via sulfur by LC-ICP-MS. • Labelling procedures for metabolic applications are also included. • The measurement of natural variations in S isotope composition with multicollector ICP-MS.

Experimental observation of strong coupling effects on the dispersion of dust acoustic waves in a plasma

OpenAIRE

Bandyopadhyay, P.; Prasad, G.; Sen, A.; Kaw, P. K.

2016-01-01

The dispersion properties of low frequency dust acoustic waves in the strong coupling regime are investigated experimentally in an argon plasma embedded with a mixture of kaolin and $MnO_2$ dust particles. The neutral pressure is varied over a wide range to change the collisional properties of the dusty plasma. In the low collisional regime the turnover of the dispersion curve at higher wave numbers and the resultant region of $\\partial\\omega/\\partial k < 0$ are identified as signatures of du...

Resonant mode for a dc plasma spray torch by means of pressure–voltage coupling: application to synchronized liquid injection

International Nuclear Information System (INIS)

Krowka, J; Rat, V; Coudert, J F

2013-01-01

Electric arc instabilities in dc plasma torches result in non-homogeneous treatment of nanosized solid particles injected into the plasma jets. In the particular case of suspension plasma spraying, large discrepancies in the particles trajectories and thermal histories make the control of coating properties more difficult to achieve. In this paper, a new approach of arc dynamics highlights the existence of different resonant modes and the possibility of their coupling. This study leads us to design a special plasma torch working in a very regular pulsed regime. Then, an innovative injection system based on the drop-on-demand method synchronized with the plasma oscillations is presented as an efficient method to control the dynamics of plasma/particles interactions. (paper)

Phosphorylation of Mycobacterium tuberculosis ParB participates in regulating the ParABS chromosome segregation system.

Science.gov (United States)

Baronian, Grégory; Ginda, Katarzyna; Berry, Laurence; Cohen-Gonsaud, Martin; Zakrzewska-Czerwińska, Jolanta; Jakimowicz, Dagmara; Molle, Virginie

2015-01-01

Here, we present for the first time that Mycobacterium tuberculosis ParB is phosphorylated by several mycobacterial Ser/Thr protein kinases in vitro. ParB and ParA are the key components of bacterial chromosome segregation apparatus. ParB is a cytosolic conserved protein that binds specifically to centromere-like DNA parS sequences and interacts with ParA, a weak ATPase required for its proper localization. Mass spectrometry identified the presence of ten phosphate groups, thus indicating that ParB is phosphorylated on eight threonines, Thr32, Thr41, Thr53, Thr110, Thr195, and Thr254, Thr300, Thr303 as well as on two serines, Ser5 and Ser239. The phosphorylation sites were further substituted either by alanine to prevent phosphorylation or aspartate to mimic constitutive phosphorylation. Electrophoretic mobility shift assays revealed a drastic inhibition of DNA-binding by ParB phosphomimetic mutant compared to wild type. In addition, bacterial two-hybrid experiments showed a loss of ParA-ParB interaction with the phosphomimetic mutant, indicating that phosphorylation is regulating the recruitment of the partitioning complex. Moreover, fluorescence microscopy experiments performed in the surrogate Mycobacterium smegmatis ΔparB strain revealed that in contrast to wild type Mtb ParB, which formed subpolar foci similar to M. smegmatis ParB, phoshomimetic Mtb ParB was delocalized. Thus, our findings highlight a novel regulatory role of the different isoforms of ParB representing a molecular switch in localization and functioning of partitioning protein in Mycobacterium tuberculosis.

Phosphorylation of Mycobacterium tuberculosis ParB participates in regulating the ParABS chromosome segregation system.

Directory of Open Access Journals (Sweden)

Grégory Baronian

Full Text Available Here, we present for the first time that Mycobacterium tuberculosis ParB is phosphorylated by several mycobacterial Ser/Thr protein kinases in vitro. ParB and ParA are the key components of bacterial chromosome segregation apparatus. ParB is a cytosolic conserved protein that binds specifically to centromere-like DNA parS sequences and interacts with ParA, a weak ATPase required for its proper localization. Mass spectrometry identified the presence of ten phosphate groups, thus indicating that ParB is phosphorylated on eight threonines, Thr32, Thr41, Thr53, Thr110, Thr195, and Thr254, Thr300, Thr303 as well as on two serines, Ser5 and Ser239. The phosphorylation sites were further substituted either by alanine to prevent phosphorylation or aspartate to mimic constitutive phosphorylation. Electrophoretic mobility shift assays revealed a drastic inhibition of DNA-binding by ParB phosphomimetic mutant compared to wild type. In addition, bacterial two-hybrid experiments showed a loss of ParA-ParB interaction with the phosphomimetic mutant, indicating that phosphorylation is regulating the recruitment of the partitioning complex. Moreover, fluorescence microscopy experiments performed in the surrogate Mycobacterium smegmatis ΔparB strain revealed that in contrast to wild type Mtb ParB, which formed subpolar foci similar to M. smegmatis ParB, phoshomimetic Mtb ParB was delocalized. Thus, our findings highlight a novel regulatory role of the different isoforms of ParB representing a molecular switch in localization and functioning of partitioning protein in Mycobacterium tuberculosis.

Measurement of the surface charge accumulation using anodic aluminum oxide(AAO) structure in an inductively coupled plasma

Science.gov (United States)

Park, Ji-Hwan; Oh, Seung-Ju; Lee, Hyo-Chang; Kim, Yu-Sin; Kim, Young-Cheol; Kim, June Young; Ha, Chang-Seoung; Kwon, Soon-Ho; Lee, Jung-Joong; Chung, Chin-Wook

2014-10-01

As the critical dimension of the nano-device shrinks, an undesired etch profile occurs during plasma etch process. One of the reasons is the local electric field due to the surface charge accumulation. To demonstrate the surface charge accumulation, an anodic aluminum oxide (AAO) membrane which has high aspect ratio is used. The potential difference between top electrode and bottom electrode in an anodic aluminum oxide contact structure is measured during inductively coupled plasma exposure. The voltage difference is changed with external discharge conditions, such as gas pressure, input power, and gas species and the result is analyzed with the measured plasma parameters.

Generation of runaway electrons during deterioration of lower hybrid power coupling in lower hybrid current drive plasmas in the HT-7 tokamak

International Nuclear Information System (INIS)

Chen, Z Y; Ju, H J; Zhu, J X; Li, M; Cai, W D; Liang, H F; Wan, B N; Shi, Y J; Xu, H D

2009-01-01

Efficient coupling of lower hybrid (LH) power from the wave launcher to the plasma is a very important issue in lower hybrid current drive (LHCD) experiments. The large unbalanced reflections in the grill trigger the LH protection system, which will trip the power, resulting in the reduction of the coupled LH power. The generation of runaway electrons has been investigated in LHCD plasmas with deterioration of LH coupling in the HT-7 tokamak. The deterioration of LH coupling results in an increase of the loop voltage and a more energetic fast electron population. These two effects favor the generation of a runaway population. It is found that most of the fast electrons generated by LH waves through parallel electron Landau damping were converted into a runaway population through the acceleration from the toroidal electric field when significant deterioration of LH coupling occurs.

Simulation of cold plasma in a chamber under high- and low-frequency voltage conditions for a capacitively coupled plasma

Institute of Scientific and Technical Information of China (English)

Hao Daoxin; Cheng Jia; Ji Linhong; Sun Yuchun

2012-01-01

The characteristics of cold plasma,especially for a dual-frequency capacitively coupled plasma (CCP),play an important role for plasma enhanced chemical vapor deposition,which stimulates further studies using different methods.In this paper,a 2D fluid model was constructed for N2 gas plasma simulations with CFD-ACE+,a commercial multi-physical software package.First,the distributions of electric potential (Epot),electron number density (Ne),N number density (N) and electron temperature (Te) are described under the condition of high frequency (HF),13.56 MHz,HF voltage,300 V,and low-frequency (LF) voltage,0 V,particularly in the sheath.Based on this,the influence of HF on Ne is further discussed under different HF voltages of 200 V,300 V,400 V,separately,along with the influence of LF,0.3 MHz,and various LF voltages of 500 V,600 V,700 V.The results show that sheaths of about 3 mm are formed near the two electrodes,in which Epot and Te vary extensively with time and space,while in the plasma bulk Epot changes synchronously with an electric potential of about 70 V and Te varies only in a small range.N is also modulated by the radio frequency,but the relative change in N is small.Ne varies only in the sheath,while in the bulk it is steady at different time steps.So,by comparing Ne in the plasma bulk at the steady state,we can see that Ne will increase when HF voltage increases.Yet,Ne will slightly decrease with the increase of LF voltage.At the same time,the homogeneity will change in both x and y directions.So both HF and LF voltages should be carefully considered in order to obtain a high-density,homogeneous plasma.

Fundamental studies of the plasma extraction and ion beam formation processes in inductively coupled plasma mass spectrometry

International Nuclear Information System (INIS)

Niu, Hongsen.

1995-01-01

The fundamental and practical aspects are described for extracting ions from atmospheric pressure plasma sources into an analytical mass spectrometer. Methodologies and basic concepts of inductively coupled plasma mass spectrometry (ICP-MS) are emphasized in the discussion, including ion source, sampling interface, supersonic expansion, slumming process, ion optics and beam focusing, and vacuum considerations. Some new developments and innovative designs are introduced. The plasma extraction process in ICP-MS was investigated by Langmuir measurements in the region between the skimmer and first ion lens. Electron temperature (T e ) is in the range 2000--11000 K and changes with probe position inside an aerosol gas flow. Electron density (n e ) is in the range 10 8 --10 10 -cm at the skimmer tip and drops abruptly to 10 6 --10 8 cm -3 near the skimmer tip and drops abruptly to 10 6 --10 8 cm -3 downstream further behind the skimmer. Electron density in the beam leaving the skimmer also depends on water loading and on the presence and mass of matrix elements. Axially resolved distributions of electron number-density and electron temperature were obtained to characterize the ion beam at a variety of plasma operating conditions. The electron density dropped by a factor of 101 along the centerline between the sampler and skimmer cones in the first stage and continued to drop by factors of 10 4 --10 5 downstream of skimmer to the entrance of ion lens. The electron density in the beam expansion behind sampler cone exhibited a 1/z 2 intensity fall-off (z is the axial position). An second beam expansion originated from the skimmer entrance, and the beam flow underwent with another 1/z 2 fall-off behind the skimmer. Skimmer interactions play an important role in plasma extraction in the ICP-MS instrument

Gas chromatography--inductively coupled plasma--time-of-flight mass spectrometry for the speciation analysis of organolead compounds in environmental water samples.

Science.gov (United States)

Heisterkamp, M; Adams, F C

2001-07-01

The application of inductively coupled plasma--time-of-flight mass spectrometry for the speciation analysis of organolead compounds in environmental waters is described. Construction of the transfer line was achieved by means of a relatively simple and rapid coupling procedure. Derivatization of the ionic lead species was achieved by in-situ propylation with sodium tetrapropylborate; simultaneous extraction of the derivatized compounds in hexane was followed by separation and detection by capillary gas chromatography hyphenated to inductively coupled plasma-time-of-flight mass spectrometry. Detection limits for the different organolead species ranged from 10 to 15 fg (as Pb), corresponding to procedural detection limits between 50 and 75 ng L(-1), on the basis of a 50 mL snow sample, extraction with 200 microL hexane, and subsequent injection of 1 microL of the organic extract on to the column. The accuracy of the system was confirmed by additional analysis of the water samples by capillary gas chromatography coupled with microwave-induced plasma-atomic-emission spectrometry and the analysis of a standard reference material CRM 605 (road dust) with a certified content of trimethyllead.

Effect of neutral gas heating in argon radio frequency inductively coupled plasma

International Nuclear Information System (INIS)

Chin, O.H.; Jayapalan, K.K.; Wong, C.S.

2014-01-01

Heating of neutral gas in inductively coupled plasma (ICP) is known to result in neutral gas depletion. In this work, this effect is considered in the simulation of the magnetic field distribution of a 13.56 MHz planar coil ICP. Measured electron temperatures and densities at argon pressures of 0.03, 0.07 and 0.2 mbar were used in the simulation whilst neutral gas temperatures were heuristically fitted. The simulated results showed reasonable agreement with the measured magnetic field profile. (author)

ULTRASONIC NEBULIZATION AND ARSENIC VALENCE STATE CONSIDERATIONS PRIOR TO DETERMINATION VIA INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY

Science.gov (United States)

An ultrasonic nebulizer (USN) was utilized as a sample introduction device for an inductively coupled plasma mass spectrometer in an attempt to increase the sensitivity for As. The USN produced a valence state response difference for As. The As response was suppressed approximate...

Study of ICRF wave propagation and plasma coupling efficiency in a linear magnetic mirror device

International Nuclear Information System (INIS)

Peng, S.Y.

1991-07-01

Ion Cyclotron Range of Frequency (ICRF) wave propagation in an inhomogeneous axial magnetic field in a cylindrical plasma-vacuum system has historically been inadequately modelled. Previous works either sacrifice the cylindrical geometry in favor of a simpler slab geometry, concentrate on the resonance region, use a single mode to represent the entire field structure, or examine only radial propagation. This thesis performs both analytical and computational studies to model the ICRF wave-plasma coupling and propagation problem. Experimental analysis is also conducted to compare experimental results with theoretical predictions. Both theoretical as well as experimental analysis are undertaken as part of the thesis. The theoretical studies simulate the propagation of ICRF waves in an axially inhomogeneous magnetic field and in cylindrical geometry. Two theoretical analysis are undertaken - an analytical study and a computational study. The analytical study treats the inhomogeneous magnetic field by transforming the (r,z) coordinate into another coordinate system (ρ,ξ) that allows the solution of the fields with much simpler boundaries. The plasma fields are then Fourier transformed into two coupled convolution-integral equations which are then differenced and solved for both the perpendicular mode number α as well as the complete EM fields. The computational study involves a multiple eigenmode computational analysis of the fields that exist within the plasma-vacuum system. The inhomogeneous axial field is treated by dividing the geometry into a series of transverse axial slices and using a constant dielectric tensor in each individual slice. The slices are then connected by longitudinal boundary conditions

Multielement determination of rare earth elements in rock sample by liquid chromatography / inductively coupled plasma mass spectrometry

International Nuclear Information System (INIS)

Hamanaka, Tadashi; Itoh, Akihide; Itoh, Shinya; Sawatari, Hideyuki; Haraguchi, Hiroki.

1995-01-01

Rare earth elements in geological standard rock sample JG-1 (granodiolite)issued from the Geological Survey of Japan have been determined by a combined system of liquid chromatography and inductively coupled plasma mass spectrometry. (author)

On the evolution of jet energy and opening angle in strongly coupled plasma

International Nuclear Information System (INIS)

Chesler, Paul M.; Rajagopal, Krishna

2016-01-01

We calculate how the energy and the opening angle of jets in N=4 SYM theory evolve as they propagate through the strongly coupled plasma of that theory. We define the rate of energy loss dE_j_e_t/dx and the jet opening angle in a straightforward fashion directly in the gauge theory before calculating both holographically, in the dual gravitational description. In this way, we rederive the previously known result for dE_j_e_t/dx without the need to introduce a finite slab of plasma. We obtain a striking relationship between the initial opening angle of the jet, which is to say the opening angle that it would have had if it had found itself in vacuum instead of in plasma, and the thermalization distance of the jet. Via this relationship, we show that N=4 SYM jets with any initial energy that have the same initial opening angle and the same trajectory through the plasma experience the same fractional energy loss. We also provide an expansion that describes how the opening angle of the N=4 SYM jets increases slowly as they lose energy, over the fraction of their lifetime when their fractional energy loss is not yet large. We close by looking ahead toward potential qualitative lessons from our results for QCD jets produced in heavy collisions and propagating through quark-gluon plasma.

Structure of the strongly coupled classical plasma in the self-consistent mean spherical approximation

International Nuclear Information System (INIS)

Chaturvedi, D.K.; Senatore, G.; Tosi, M.P.

1980-10-01

An analytic theory is presented for the static structure factor of the one-component classical plasma at strong couplings. The theory combines the hard-core model of Gillan for short-range correlations in the Coulomb fluid with a semiempirical representation of intermediate-range correlations, through which the requirement of thermodynamic consistency on the ''compressibility'' and the known equation of state of the system are satisfied. Excellent agreement is found with the available computer simulation data on the structure of the fluid. The approach becomes inapplicable at intermediate and weak couplings where effects of penetration in the Coulomb hole of each particle become important. (author)

Plasma analysis of inductively coupled impulse sputtering of Cu, Ti and Ni

Science.gov (United States)

Loch, D. A. L.; Aranda Gonzalvo, Y.; Ehiasarian, A. P.

2017-06-01

Inductively coupled impulse sputtering (ICIS) is a new development in the field of highly ionised pulsed PVD processes. For ICIS the plasma is generated by an internal inductive coil, replacing the need for a magnetron. To understand the plasma properties, measurements of the current and voltage waveforms at the cathode were conducted. The ion energy distribution functions (IEDFs) were measured by energy resolved MS and plasma chemistry was analysed by OES and then compared to a model. The target was operated in pulsed DC mode and the coil was energised by pulsed RF power, with a duty cycle of 7.5%. At a constant pressure (14 Pa) the set peak RF power was varied from 1000-4000 W. The DC voltage to the target was kept constant at 1900 V. OES measurements have shown a monotonic increase in intensity with increasing power. Excitation and ionisation processes were single step for ICIS of Ti and Ni and multi-step for Cu. The latter exhibited an unexpectedly steep rise in ionisation efficiency with power. The IEDFs measured by MS show the material- and time-dependant plasma potential in the range of 10-30 eV, ideal for increased surface mobility without inducing lattice defects. A lower intensity peak, of high energetic ions, is visible at 170 eV during the pulse.

Plasma concentrations of soluble urokinase-type plasminogen activator receptor are increased in patients with malaria and are associated with a poor clinical or a fatal outcome

DEFF Research Database (Denmark)

Ostrowski, Sisse R; Ullum, Henrik; Goka, Bamenla Q

2005-01-01

PAR are associated with disease severity in malaria. METHODS: At admission to the hospital, plasma concentrations of suPAR were measured by ELISA in samples from 645 African children with clinical symptoms of malaria: 478 had malaria, and 167 had a blood film negative for Plasmodium parasites. Fourteen healthy......BACKGROUND: Blood concentrations of soluble urokinase-type plasminogen activator receptor (suPAR) are increased in conditions with immune activation, and high concentrations of suPAR often predict a poor clinical outcome. This study explored the hypothesis that high plasma concentrations of su......: If the plasma concentration of suPAR reflects the extent of parasite-induced immune activation, this may explain why a high concentration of suPAR is associated with a poor clinical outcome in patients with malaria....

Transport and trapping of dust particles in a potential well created by inductively coupled diffused plasmas.

Science.gov (United States)

Choudhary, Mangilal; Mukherjee, S; Bandyopadhyay, P

2016-05-01

A versatile linear dusty (complex) plasma device is designed to study the transport and dynamical behavior of dust particles in a large volume. Diffused inductively coupled plasma is generated in the background of argon gas. A novel technique is used to introduce the dust particles in the main plasma by striking a secondary direct current glow discharge. These dust particles are found to get trapped in an electrostatic potential well, which is formed due to the combination of the ambipolar electric field caused by diffusive plasma and the field produced by the charged glass wall of the vacuum chamber. According to the requirements, the volume of the dust cloud can be controlled very precisely by tuning the plasma and discharge parameters. The present device can be used to address the underlying physics behind the transport of dust particles, self-excited dust acoustic waves, and instabilities. The detailed design of this device, plasma production and characterization, trapping and transport of the dust particle, and some of the preliminary experimental results are presented.

Characteristics of the plasma injected into D.E.C.A. 2; Caracteristiques du plasma injecte dans D.E.C.A. 2

Energy Technology Data Exchange (ETDEWEB)

Lecoustey, P; Luc, H; Tachon, J; Veron, D [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1963-07-01

Deuterium plasma is injected from an electrode-less plasma gun along the lines of force of a static magnetic field. This field is constant over length of 1 m; it increases thereafter in a 10 to 1 ratio over a 4 meter length up to the chamber where the measurements are carried out. Density measurements are performed using Faraday cups and an 8.6 mm microwave interferometer. For instance in a 1600 G magnetic field a 0.5 x 10{sup 13} deutons/cm{sup 3} density arises for a plasma with velocity 3 x 10{sup 7} cm/s. The transverse energy is first determined from the diamagnetic signal amplitude of magnetic loops. The main results are obtained from the study of plasma transmitted through a magnetic barrier by means of measurements made with a Faraday cup, magnetic loops and thermocouples. The results given by these different methods are in good agreement and allow to define for the whole of the plasma flow a mean < {theta} > value for the ions pitch angle. In a 1600 G, < {theta} > equal 32 degrees; i.e. mean transverse energy of 360 eV for a plasma with a 030 eV longitudinal energy (a velocity equal to 3 x 10{sup 7} cm/s). The high value of the transverse energy might be attributed to a pre-compression in the field gradient. Preliminary measurements seem to indicate the possibility of trapping the plasma between two magnetic barriers. (authors) [French] Un plasma de deuterium est injecte par un canon a induction parallelement aux lignes de force d'un champ magnetique statique, constant sur une longueur de 1 m et ensuite croissant dans un rapport 10 a 1 sur une longueur de 4 m, jusque dans la chambre ou sont effectuees les mesures. La densite est determinee par des mesures d'interferometrie hertzienne et au moyen de cylindres de Faraday. Par exemple dans un champ de 1600 G on trouve une densite de 0,5 x 10{sup 13} deutons/cm{sup 3} pour un plasma anime d'une vitesse de 3 x 10{sup 7} cm/s. Une premiere determination de l'energie transversale est faite a partir des signaux

Viscosity of two-dimensional strongly coupled dusty plasma modified by a perpendicular magnetic field

Science.gov (United States)

Feng, Yan; Lin, Wei; Murillo, M. S.

2017-11-01

Transport properties of two-dimensional (2D) strongly coupled dusty plasmas have been investigated in detail, but never for viscosity with a strong perpendicular magnetic field; here, we examine this scenario using Langevin dynamics simulations of 2D liquids with a binary Yukawa interparticle interaction. The shear viscosity η of 2D liquid dusty plasma is estimated from the simulation data using the Green-Kubo relation, which is the integration of the shear stress autocorrelation function. It is found that, when a perpendicular magnetic field is applied, the shear viscosity of 2D liquid dusty plasma is modified substantially. When the magnetic field is increased, its viscosity increases at low temperatures, while at high temperatures its viscosity diminishes. It is determined that these different variational trends of η arise from the different behaviors of the kinetic and potential parts of the shear stress under external magnetic fields.

Polyatomic ions in inductively coupled plasma-mass spectrometry

International Nuclear Information System (INIS)

Ferguson, Jill Wisnewski; Dudley, Timothy J.; Sears, Kyle C.; McIntyre, Sally M.; Gordon, Mark S.; Houk, R.S.

2009-01-01

Several polyatomic ions in inductively coupled plasma-mass spectrometry are studied experimentally and by computational methods. Novel calculations based on spin-restricted open shell second order perturbation theory (ZAPT2) and coupled cluster (CCSD(T)) theory are performed to determine the energies, structures and partition functions of the ions. These values are combined with experimental data to evaluate a dissociation constant and gas kinetic temperature (T gas ) value. In our opinion, the resulting T gas value can sometimes be interpreted to deduce the location where the polyatomic ion of interest is generated. The dissociation of N 2 H + to N 2 + leads to a calculated T gas of 4550 to 4900 K, depending on the computational data used. The COH + to CO + system yields a similar temperature, which is not surprising considering the similar energies and structures of COH + and N 2 H + . The dissociation of H 2 CO + to HCO + leads to a much lower T gas ( 2 COH + to HCOH + generates a T gas value between those from the other H x CO + ions studied here. All of these measured T gas values correspond to formation of extra polyatomic ion in the interface or extraction region. The computations reveal the existence of isomers such as HCO + and COH + , and H 2 CO + and HCOH + , which have virtually the same m/z values and need to be considered in the interpretation of results.

Computational hydrodynamics and optical performance of inductively-coupled plasma adaptive lenses

Energy Technology Data Exchange (ETDEWEB)

Mortazavi, M.; Urzay, J., E-mail: jurzay@stanford.edu; Mani, A. [Center for Turbulence Research, Stanford University, Stanford, California 94305-3024 (United States)

2015-06-15

This study addresses the optical performance of a plasma adaptive lens for aero-optical applications by using both axisymmetric and three-dimensional numerical simulations. Plasma adaptive lenses are based on the effects of free electrons on the phase velocity of incident light, which, in theory, can be used as a phase-conjugation mechanism. A closed cylindrical chamber filled with Argon plasma is used as a model lens into which a beam of light is launched. The plasma is sustained by applying a radio-frequency electric current through a coil that envelops the chamber. Four different operating conditions, ranging from low to high powers and induction frequencies, are employed in the simulations. The numerical simulations reveal complex hydrodynamic phenomena related to buoyant and electromagnetic laminar transport, which generate, respectively, large recirculating cells and wall-normal compression stresses in the form of local stagnation-point flows. In the axisymmetric simulations, the plasma motion is coupled with near-wall axial striations in the electron-density field, some of which propagate in the form of low-frequency traveling disturbances adjacent to vortical quadrupoles that are reminiscent of Taylor-Görtler flow structures in centrifugally unstable flows. Although the refractive-index fields obtained from axisymmetric simulations lead to smooth beam wavefronts, they are found to be unstable to azimuthal disturbances in three of the four three-dimensional cases considered. The azimuthal striations are optically detrimental, since they produce high-order angular aberrations that account for most of the beam wavefront error. A fourth case is computed at high input power and high induction frequency, which displays the best optical properties among all the three-dimensional simulations considered. In particular, the increase in induction frequency prevents local thermalization and leads to an axisymmetric distribution of electrons even after introduction of

Analysis of non-equilibrium phenomena in inductively coupled plasma generators

Energy Technology Data Exchange (ETDEWEB)

Zhang, W.; Panesi, M., E-mail: mpanesi@illinois.edu [University of Illinois at Urbana-Champaign, Urbana, Illinois 61822 (United States); Lani, A. [Von Karman Institute for Fluid Dynamics, Rhode-Saint-Genèse (Belgium)

2016-07-15

This work addresses the modeling of non-equilibrium phenomena in inductively coupled plasma discharges. In the proposed computational model, the electromagnetic induction equation is solved together with the set of Navier-Stokes equations in order to compute the electromagnetic and flow fields, accounting for their mutual interaction. Semi-classical statistical thermodynamics is used to determine the plasma thermodynamic properties, while transport properties are obtained from kinetic principles, with the method of Chapman and Enskog. Particle ambipolar diffusive fluxes are found by solving the Stefan-Maxwell equations with a simple iterative method. Two physico-mathematical formulations are used to model the chemical reaction processes: (1) A Local Thermodynamics Equilibrium (LTE) formulation and (2) a thermo-chemical non-equilibrium (TCNEQ) formulation. In the TCNEQ model, thermal non-equilibrium between the translational energy mode of the gas and the vibrational energy mode of individual molecules is accounted for. The electronic states of the chemical species are assumed in equilibrium with the vibrational temperature, whereas the rotational energy mode is assumed to be equilibrated with translation. Three different physical models are used to account for the coupling of chemistry and energy transfer processes. Numerical simulations obtained with the LTE and TCNEQ formulations are used to characterize the extent of non-equilibrium of the flow inside the Plasmatron facility at the von Karman Institute. Each model was tested using different kinetic mechanisms to assess the sensitivity of the results to variations in the reaction parameters. A comparison of temperatures and composition profiles at the outlet of the torch demonstrates that the flow is in non-equilibrium for operating conditions characterized by pressures below 30 000 Pa, frequency 0.37 MHz, input power 80 kW, and mass flow 8 g/s.

The PERC trademark process: Existing and potential applications for induction coupled plasma technology in hazardous and radioactive waste treatment

International Nuclear Information System (INIS)

Blutke, A.S.; Vavruska, J.S.; Serino, J.F.

1996-01-01

Plasma Technology, Inc. (PTI), a Santa Fe, New Mexico corporation has developed the Plasma Energy Recycle and Conversion (PERC)trademark treatment process as a safe and environmentally clean alternative to conventional thermal destruction technologies. The PERC trademark treatment process uses as its heat source an advanced Induction Coupled Plasma (ICP) torch connected to a reaction chamber system with an additional emission control system. For example, organic-based gas, liquid, slurry, and/or solid waste streams can be converted into usable or even salable products while residual emissions are reduced to an absolute minimum. In applications for treatment of hazardous and radioactive waste streams, the PERC system could be used for destruction of the hazardous organic constituents and/or significant waste volume reduction while capturing the radioactive fraction in a non-leachable form. Like Direct Current (DC) and Alternating Current (AC) arc plasma systems, ICP torches offer sufficient energy to decompose, melt and/or vitrify any waste stream. The decision for an arc plasma or an IC plasma system has to be made on a case by case evaluation and is highly dependent on the specific waste stream's form and composition. Induction coupled plasma technology offers one simple, but significant difference compared to DC or AC arc plasma systems: the ICP torch is electrodeless. To date, enormous research effort has been spent to improve the lifetime of electrodes and the effectiveness of related cooling systems. Arc plasma systems are established in research laboratories worldwide and are approaching a broad use in commercial applications. ICP technology has been improved relatively recently, but nowadays offers complete new and beneficial approaches in the field of waste conversion and treatment

''Top-down'' versus ''side-on'' viewing of the inductively coupled plasma

International Nuclear Information System (INIS)

Faires, L.M.; Bieniewski, T.M.; Apel, C.T.; Niemczyk, T.M.

1985-01-01

The inductively coupled plasma is viewed by a ''top-down'' optical configuration, and the analytical performance is compared to conventional ''side-on'' viewing in terms of sensitivity, detection limits, linear dynamical range, self-reversal effects, and multielement performance. This comparison is made for a selection of eleven atom and ion lines of eight elements. The results of this study indicate distinct advantages in ''top-down'' viewing including improved sensitivity, lower detection limits, better signal-to-background ratios, and better compromise viewing position for multielement analysis. An exception to these advantages is increased self-absorption effects observed for the alkali elements

Matrix separation by chelation to prepare biological materials for isotopic zinc analysis by inductively coupled plasma mass spectrometry

International Nuclear Information System (INIS)

Durrant, S.F.; Krushevska, A.; Amarasiriwardena, D.; Argentine, M.D.; Romon-Guesnier, S.; Barnes, R.M.

1994-01-01

Following an evaluation of three chelating resins [Chelex-100, poly(dithiocarbamate) (PDTC) and carboxymethylated poly(ethyleneimine)-poly(methylenepolyphenylene) isocyanate (CPPI)], a procedure was established with the last of these for the separation of Zn from biological matrix elements prior to 70 Zn: 68 Zn isotopic analysis by inductively coupled plasma mass spectrometry (ICP-MS). The method was verified by establishing Zn recoveries and by determining its effectiveness in removing Cl and Na from buffered test solutions. Calcium, Na, and Zn concentration data were determined by inductively coupled plasma atomic emission spectrometry. Chlorine was measured by electrothermal vaporization ICP-MS. The efficacy of the technique was demonstrated by the determination of zinc isotope ratios in bovine milk and human urine. (Author)

ParA and ParB coordinate chromosome segregation with cell elongation and division during Streptomyces sporulation

Science.gov (United States)

Donczew, Magdalena; Mackiewicz, Paweł; Wróbel, Agnieszka; Flärdh, Klas; Zakrzewska-Czerwińska, Jolanta

2016-01-01

In unicellular bacteria, the ParA and ParB proteins segregate chromosomes and coordinate this process with cell division and chromosome replication. During sporulation of mycelial Streptomyces, ParA and ParB uniformly distribute multiple chromosomes along the filamentous sporogenic hyphal compartment, which then differentiates into a chain of unigenomic spores. However, chromosome segregation must be coordinated with cell elongation and multiple divisions. Here, we addressed the question of whether ParA and ParB are involved in the synchronization of cell-cycle processes during sporulation in Streptomyces. To answer this question, we used time-lapse microscopy, which allows the monitoring of growth and division of single sporogenic hyphae. We showed that sporogenic hyphae stop extending at the time of ParA accumulation and Z-ring formation. We demonstrated that both ParA and ParB affect the rate of hyphal extension. Additionally, we showed that ParA promotes the formation of massive nucleoprotein complexes by ParB. We also showed that FtsZ ring assembly is affected by the ParB protein and/or unsegregated DNA. Our results indicate the existence of a checkpoint between the extension and septation of sporogenic hyphae that involves the ParA and ParB proteins. PMID:27248800

Applications of inductively coupled plasma spectroscopy to geochemical reconnaissance for uranium exploration

International Nuclear Information System (INIS)

Cagle, G.W.; Butz, T.R.

1980-01-01

The analysis of large numbers of natural groundwater and stream sediment samples by Inductively Coupled Plasma (ICP) Spectroscopy has been applied to a geochemical reconnaissance program as part of the National Uranium Resource Evaluation Program. Approximately 25 elements have been determined in over 60,000 samples by ICP analysis. These data are combined with additional measurements obtained by atomic absorption, colorimetry, neutron activation, and fluorescence spectroscopy. Results are presented and interpreted in terms of the uranium favorability of areas in Texas where this survey has been completed

Effects of weakly coupled and dense quantum plasmas environments on charge exchange and ionization processes in Na+ + Rb(5s) atom collisions

Science.gov (United States)

Pandey, Mukesh Kumar; Lin, Yen-Chang; Ho, Yew Kam

2017-02-01

The effects of weakly coupled or classical and dense quantum plasmas environment on charge exchange and ionization processes in Na+ + Rb(5s) atom collision at keV energy range have been investigated using classical trajectory Monte Carlo (CTMC) method. The interaction of three charged particles are described by the Debye-Hückel screen potential for weakly coupled plasma, whereas exponential cosine-screened Coulomb potential have been used for dense quantum plasma environment and the effects of both conditions on the cross sections are compared. It is found that screening effects on cross sections in high Debye length condition is quite small in both plasma environments. However, enhanced screening effects on cross sections are observed in dense quantum plasmas for low Debye length condition, which becomes more effective while decreasing the Debye length. Also, we have found that our calculated results for plasma-free case are comparable with the available theoretical results. These results are analyzed in light of available theoretical data with the choice of model potentials.

Charging-delay effect on longitudinal dust acoustic shock wave in strongly coupled dusty plasma

International Nuclear Information System (INIS)

Ghosh, Samiran; Gupta, M.R.

2005-01-01

Taking into account the charging-delay effect, the nonlinear propagation characteristics of longitudinal dust acoustic wave in strongly coupled collisional dusty plasma described by generalized hydrodynamic model have been investigated. In the 'hydrodynamic limit', a Korteweg-de Vries Burger (KdVB) equation with a damping term arising due to dust-neutral collision is derived in which the Burger term is proportional to the dissipation due to dust viscosity through dust-dust correlation and charging-delay-induced anomalous dissipation. On the other hand, in the 'kinetic limit', a KdVB equation with a damping term and a nonlocal nonlinear forcing term arising due to memory-dependent strong correlation effect of dust fluid is derived in which the Burger term depends only on the charging-delay-induced dissipation. Numerical solution of integrodifferential equations reveals that (i) dissipation due to dust viscosity and principally due to charging delay causes excitation of the longitudinal dust acoustic shock wave in strongly coupled dusty plasma and (ii) dust-neutral collision does not appear to play any direct role in shock formation. The condition for the generation of shock is also discussed briefly

Coupled tearing modes in plasmas with differential rotation

International Nuclear Information System (INIS)

Dewar, R.L.; Persson, M.

1993-08-01

The global asymptotic matching equations for multiple coupled resistive modes of arbitrary parity in a cylindrical plasma are derived. Three different variational principles are given for the outer region matching data, while the inner-region analysis features a careful treatment of the symmetry-breaking effect of a gradient in the equilibrium current for a zero-β slab model. It is concluded that the usual constant-ψ result remains valid and constrains the matrix matching formalism. The dispersion relation is compared with initial value calculations of a double tearing mode when there are small relative rotation velocities between the rational surfaces. In treating differential rotation within the asymptotic matching formalism, flow is ignored in the outer region and is assumed to affect the inner response solely through a Doppler shift. It is shown that the relative rotation can have a strong stabilizing effect by making all but one rational surface effectively ideal. 40 refs., 6 figs

Diagnostic of capacitively coupled radio frequency plasma from electrical discharge characteristics: comparison with optical emission spectroscopy and fluid model simulation

Science.gov (United States)

Xiang, HE; Chong, LIU; Yachun, ZHANG; Jianping, CHEN; Yudong, CHEN; Xiaojun, ZENG; Bingyan, CHEN; Jiaxin, PANG; Yibing, WANG

2018-02-01

The capacitively coupled radio frequency (CCRF) plasma has been widely used in various fields. In some cases, it requires us to estimate the range of key plasma parameters simpler and quicker in order to understand the behavior in plasma. In this paper, a glass vacuum chamber and a pair of plate electrodes were designed and fabricated, using 13.56 MHz radio frequency (RF) discharge technology to ionize the working gas of Ar. This discharge was mathematically described with equivalent circuit model. The discharge voltage and current of the plasma were measured at different pressures and different powers. Based on the capacitively coupled homogeneous discharge model, the equivalent circuit and the analytical formula were established. The plasma density and temperature were calculated by using the equivalent impedance principle and energy balance equation. The experimental results show that when RF discharge power is 50-300 W and pressure is 25-250 Pa, the average electron temperature is about 1.7-2.1 eV and the average electron density is about 0.5 × 1017-3.6 × 1017 m-3. Agreement was found when the results were compared to those given by optical emission spectroscopy and COMSOL simulation.

Magnetic fields and uniformity of radio frequency power deposition in low-frequency inductively coupled plasmas with crossed internal oscillating currents

International Nuclear Information System (INIS)

Tsakadze, E.L.; Ostrikov, K.; Tsakadze, Z.L.; Vladimirov, S.V.; Xu, S.

2004-01-01

Radial and axial distributions of magnetic fields in a low-frequency (∼460 kHz) inductively coupled plasma source with two internal crossed planar rf current sheets are reported. The internal antenna configuration comprises two orthogonal sets of eight alternately reconnected parallel and equidistant copper litz wires in quartz enclosures and generates three magnetic (H z , H r , and H φ ) and two electric (E φ and E r ) field components at the fundamental frequency. The measurements have been performed in rarefied and dense plasmas generated in the electrostatic (E) and electromagnetic (H) discharge modes using two miniature magnetic probes. It is shown that the radial uniformity and depth of the rf power deposition can be improved as compared with conventional sources of inductively coupled plasmas with external flat spiral ('pancake') antennas. Relatively deeper rf power deposition in the plasma source results in more uniform profiles of the optical emission intensity, which indicates on the improvement of the plasma uniformity over large chamber volumes. The results of the numerical modeling of the radial magnetic field profiles are found in a reasonable agreement with the experimental data

Pyrolysis treatment of waste tire powder in a capacitively coupled RF plasma reactor

Energy Technology Data Exchange (ETDEWEB)

Huang, H. [Department of Environmental Engineering, Guangdong University of Technology, Waihuanxi Road, Guangzhou 510006 (China); Tang, L. [Department of Civil Engineering, Guangzhou University, Waihuanxi Road, Guangzhou 510006 (China)

2009-03-15

A capacitively coupled radio-frequency (RF) plasma reactor was tested mainly for the purpose of solid waste treatment. It was found that using a RF input power between 1600 and 2000 W and a reactor pressure between 3000 and 8000 Pa (absolute pressure), a reactive plasma environment with a gas temperature between 1200 and 1800 K can be reached in this lab scale reactor. Under these conditions, pyrolysis of tire powder gave two product streams: a combustible gas and a pyrolytic char. The major components of the gas product are H{sub 2}, CO, CH{sub 4}, and CO{sub 2} The physical properties (surface area, porosity, and particle morphology) as well as chemical properties (elemental composition, heating value, and surface functional groups) of the pyrolytic char has also been examined. (author)

Computational Fluid Dynamics Analysis of Cold Plasma Plume Mixing with Blood Using Level Set Method Coupled with Heat Transfer

Directory of Open Access Journals (Sweden)

Mehrdad Shahmohammadi Beni

2017-06-01

Full Text Available Cold plasmas were proposed for treatment of leukemia. In the present work, conceptual designs of mixing chambers that increased the contact between the two fluids (plasma and blood through addition of obstacles within rectangular-block-shaped chambers were proposed and the dynamic mixing between the plasma and blood were studied using the level set method coupled with heat transfer. Enhancement of mixing between blood and plasma in the presence of obstacles was demonstrated. Continuous tracking of fluid mixing with determination of temperature distributions was enabled by the present model, which would be a useful tool for future development of cold plasma devices for treatment of blood-related diseases such as leukemia.

Par Pond water balance

International Nuclear Information System (INIS)

Hiergesell, R.A.; Dixon, K.L.

1996-06-01

A water budget for the Par Pond hydrologic system was established in order to estimate the rate of groundwater influx to Par Pond. This estimate will be used in modeling exercises to predict Par Pond reservoir elevation and spillway discharge in the scenario where Savannah River water is no longer pumped and discharged into Par Pond. The principal of conservation of mass was used to develop the water budget, where water inflow was set equal to water outflow. Components of the water budget were identified, and the flux associated with each was determined. The water budget was considered balanced when inflow and outflow summed to zero. The results of this study suggest that Par Pond gains water from the groundwater system in the upper reaches of the reservoir, but looses water to the groundwater system near the dam. The rate of flux of groundwater from the water table aquifer into Par Pond was determined to be 13 cfs. The rate of flux from Par Pond to the water table aquifer near the dam was determined to be 7 cfs

Determination of Arsenic in Sinus Wash and Tap Water by Inductively Coupled Plasma-Mass Spectrometry

Science.gov (United States)

Donnell, Anna M.; Nahan, Keaton; Holloway, Dawone; Vonderheide, Anne P.

2016-01-01

Arsenic is a toxic element to which humans are primarily exposed through food and water; it occurs as a result of human activities and naturally from the earth's crust. An experiment was developed for a senior level analytical laboratory utilizing an Inductively Coupled Plasma-Mass Spectrometer (ICP-MS) for the analysis of arsenic in household…

Determining the microwave coupling and operational efficiencies of a microwave plasma assisted chemical vapor deposition reactor under high pressure diamond synthesis operating conditions

Energy Technology Data Exchange (ETDEWEB)

Nad, Shreya [Department of Electrical and Computer Engineering, Michigan State University, East Lansing, Michigan 48824 (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824 (United States); Gu, Yajun; Asmussen, Jes [Department of Electrical and Computer Engineering, Michigan State University, East Lansing, Michigan 48824 (United States)

2015-07-15

The microwave coupling efficiency of the 2.45 GHz, microwave plasma assisted diamond synthesis process is investigated by experimentally measuring the performance of a specific single mode excited, internally tuned microwave plasma reactor. Plasma reactor coupling efficiencies (η) > 90% are achieved over the entire 100–260 Torr pressure range and 1.5–2.4 kW input power diamond synthesis regime. When operating at a specific experimental operating condition, small additional internal tuning adjustments can be made to achieve η > 98%. When the plasma reactor has low empty cavity losses, i.e., the empty cavity quality factor is >1500, then overall microwave discharge coupling efficiencies (η{sub coup}) of >94% can be achieved. A large, safe, and efficient experimental operating regime is identified. Both substrate hot spots and the formation of microwave plasmoids are eliminated when operating within this regime. This investigation suggests that both the reactor design and the reactor process operation must be considered when attempting to lower diamond synthesis electrical energy costs while still enabling a very versatile and flexible operation performance.

Core-edge coupling and the effect of the edge on overall plasma performance

International Nuclear Information System (INIS)

Fichtmueller, M.; Corrigan, G.; Lauro-Taroni, L.

1999-01-01

Several attempts to model the entire plasma cross section have been reported in the last few years. Two possibilities are to either couple a core code to a scrape-off layer (SOL) code at a specified interface or to extend the computational region of an SOL-code all the way to the plasma centre. The most advanced global code is the code COCONUT which is based on the former principle and comprises the Monte-Carlo code NIMBUS, the 2D scrape-off layer code EDGE2D, the core transport code JETTO and the core impurity transport code SANCO. A main feature of COCONUT is its modular structure which ensures a high degree of flexibility and the capability to cover a large range of time-scales. The influence of the SOL on the core is illustrated with a range of global simulations carried out with COCONUT. The simulations show that the primary effect of the SOL is the control of the particle sources and sinks with a secondary effect on plasma dilution, radiation and perhaps pedestal temperatures. (author)

Online tuning of impedance matching circuit for long pulse inductively coupled plasma source operation—An alternate approach

International Nuclear Information System (INIS)

Sudhir, Dass; Bandyopadhyay, M.; Chakraborty, A.; Kraus, W.; Gahlaut, A.; Bansal, G.

2014-01-01

Impedance matching circuit between radio frequency (RF) generator and the plasma load, placed between them, determines the RF power transfer from RF generator to the plasma load. The impedance of plasma load depends on the plasma parameters through skin depth and plasma conductivity or resistivity. Therefore, for long pulse operation of inductively coupled plasmas, particularly for high power (∼100 kW or more) where plasma load condition may vary due to different reasons (e.g., pressure, power, and thermal), online tuning of impedance matching circuit is necessary through feedback. In fusion grade ion source operation, such online methodology through feedback is not present but offline remote tuning by adjusting the matching circuit capacitors and tuning the driving frequency of the RF generator between the ion source operation pulses is envisaged. The present model is an approach for remote impedance tuning methodology for long pulse operation and corresponding online impedance matching algorithm based on RF coil antenna current measurement or coil antenna calorimetric measurement may be useful in this regard

Grain dynamics and inter-grain coupling in dusty plasma Coulomb crystals

International Nuclear Information System (INIS)

Rahman, H.U.; Mohideen, U.; Smith, M.A.; Rosenberg, M.; Mendis, D.A.

2001-01-01

We review our results on the lattice structure and the lattice dynamics of dusty plasma Coulomb crystals formed in rectangular conductive grooves. The basic structure appears to be made of mutually repulsive columns of grains confined by the walls of the groove. The columns are oriented along the direction of the electrode sheath electric field. Inter-grain coupling as a function of plasma temperature and density were investigated by measurement of these parameters. A simple phenomenological model wherein the inter-grain spacing along the column results from an attractive electric field induced dipole-dipole force balanced by a repulsive monopole Coulomb force is consistent with observed features of the Coulomb crystal. In addition, here we present some preliminary measurements of the vibration and rotation dynamics of the individual grains in the Coulomb crystal. The thermal energy of the dust grain thus calculated is much less than the inter-grain Coulomb potential energy as required for the formation of stable structures. Also the observed rotational frequency is consistent with the assumption of thermal equilibrium between the dust grains and the neutral gas. (orig.)

New system for vacuum deposition of refractory materials using an atmospheric-pressure inductively coupled plasma

International Nuclear Information System (INIS)

Merkle, B.D.; Kniseley, R.N.; Schmidt, F.A.

1987-01-01

We have successfully developed a technique utilizing an atmospheric-pressure inductively coupled plasma combined with a low-pressure deposition chamber for deposition of thin films. The equipment and method of operation are discussed. Refractory powders (Nb and Y 2 O 3 ) were injected into the plasma and deposited as Nb and substoichiometric yttrium oxide, YO/sub 1.49/, onto Fe and Cu substrates. The substoichiometric yttrium oxide deposit adhered well to the Fe and Cu substrates, while the Nb deposit adhered well to the Fe only. The Nb deposit on the Cu substrate flaked and peeled probably because of stresses induced from the thermal expansion mismatch between the Nb and Cu. Further studies will be undertaken to better understand the processes occurring in this type of plasma-coating system in order to optimize the instrumental parameters for particular coating applications

suPAR

DEFF Research Database (Denmark)

Hodges, Gethin W; Bang, Casper N; Wachtell, Kristian

2015-01-01

The fundamental role of inflammation in cardiovascular disease (CVD) has prompted interest in numerous biomarkers that detect subclinical levels of inflammation. Soluble urokinase plasminogen activator receptor (suPAR) is a novel biomarker that correlates significantly with cardiovascular events ...... comprehensive review of suPAR in CVD and explore its function and usefulness in predicting cardiovascular events....

Surface roughening of ground fused silica processed by atmospheric inductively coupled plasma

International Nuclear Information System (INIS)

Xin, Qiang; Li, Na; Wang, Jun; Wang, Bo; Li, Guo; Ding, Fei; Jin, Huiliang

2015-01-01

Highlights: • The morphology evolution of ground fused silica, processed by atmospheric plasma, was investigated experimentally. • The roughness development results from opening and coalescing of the plasma-etched cracks. • The shapes of grain-like etched pits are the results of the adjacent cracks coalescing with one another. • The descent of the pits density is due to some smaller etched pits that are swallowed up by larger pits. • Leading role in surface smoothing is laterally etching away the side walls of the intersecting pits. - Abstract: Subsurface damage (SSD) is a defect that is inevitably induced during mechanical processes, such as grinding and polishing. This defect dramatically reduces the mechanical strength and the laser damage thresholds of optical elements. Compared with traditional mechanical machining, atmospheric pressure plasma processing (APPP) is a relatively novel technology that induces almost no SSD during the processing of silica-based optical materials. In this paper, a form of APPP, inductively coupled plasma (ICP), is used to process fused silica substrates with fluorocarbon precursor under atmospheric pressure. The surface morphology evolution of ICP-processed substrates was observed and characterized by confocal laser scanning microscope (CLSM), field emission scanning electron microscope (SEM), and atomic force microscopy (AFM). The results show that the roughness evolves with the etching depth, and the roughness evolution is a single-peaked curve. This curve results from the opening and the coalescing of surface cracks and fractures. The coalescence procedure of these microstructures was simulated with two common etched pits on a polished fused silica surface. Understanding the roughness evolution of plasma-processed surface might be helpful in optimizing the optical fabrication chain that contains APPP

Surface roughening of ground fused silica processed by atmospheric inductively coupled plasma

Energy Technology Data Exchange (ETDEWEB)

Xin, Qiang; Li, Na; Wang, Jun; Wang, Bo, E-mail: bradywang@hit.edu.cn; Li, Guo; Ding, Fei; Jin, Huiliang

2015-06-30

Highlights: • The morphology evolution of ground fused silica, processed by atmospheric plasma, was investigated experimentally. • The roughness development results from opening and coalescing of the plasma-etched cracks. • The shapes of grain-like etched pits are the results of the adjacent cracks coalescing with one another. • The descent of the pits density is due to some smaller etched pits that are swallowed up by larger pits. • Leading role in surface smoothing is laterally etching away the side walls of the intersecting pits. - Abstract: Subsurface damage (SSD) is a defect that is inevitably induced during mechanical processes, such as grinding and polishing. This defect dramatically reduces the mechanical strength and the laser damage thresholds of optical elements. Compared with traditional mechanical machining, atmospheric pressure plasma processing (APPP) is a relatively novel technology that induces almost no SSD during the processing of silica-based optical materials. In this paper, a form of APPP, inductively coupled plasma (ICP), is used to process fused silica substrates with fluorocarbon precursor under atmospheric pressure. The surface morphology evolution of ICP-processed substrates was observed and characterized by confocal laser scanning microscope (CLSM), field emission scanning electron microscope (SEM), and atomic force microscopy (AFM). The results show that the roughness evolves with the etching depth, and the roughness evolution is a single-peaked curve. This curve results from the opening and the coalescing of surface cracks and fractures. The coalescence procedure of these microstructures was simulated with two common etched pits on a polished fused silica surface. Understanding the roughness evolution of plasma-processed surface might be helpful in optimizing the optical fabrication chain that contains APPP.

C9.A/14 steelwork joints de poutres par plaque frontale : assemblages par gousset

CERN Document Server

2015-01-01

Les Tables de résistances ultimes des assemblages boulonnés par plaque frontale et par gousset, complétées par une description des modèles de calcul et des exemples d’application, ont pour but de faciliter la tâche de l'ingénieur et du constructeur. Cette première partie C9.A/14 contient les chapitres suivants: - Joints de poutres par plaque frontale en acier S235 et S355 - Assemblages par gousset en acier S235 et S355 Les Tables contiennent des données relatives à la géométrie ainsi que les valeurs de calcul correspondantes des résistances ultimes des assemblages ; elles remplacent le chapitre « Assemblages par plaques frontales et boulons HR » des anciennes Tables C9.1 de 1983 / 2002. Le calcul de ces assemblages par plaque frontale est basé sur les hypothèses du modèle de la méthode des composants décrite dans la norme SN EN 1993-1-8. Les vérifications sont effectuées selon la norme SIA 263:2013. Les assemblages par gousset remplacent les assemblages par double cornière, (telle...

Application of capacitively coupled rf discharge plasma for sterilization of polymer materials used in ophthalmology

International Nuclear Information System (INIS)

Abdullin, I.Sh.; Avetisov, S.E.; Lipatov, D.V.; Rybakova, E.G.; Bragin, V.E.; Bykanov, A.N.; Kamarentsev, E.N.

1996-01-01

The sterilization effect of capacitively coupled rf discharge plasma treatment of contact lenses was investigated. There were used two types of polymer: highly hydrophilic polymer with water content 76% (Navelen-76) and poly-methylmethacrylate (PMMA). There was demonstrated the possibility of effective sterilization by RF discharge plasma of a set of polymer materials used in ophthalmology. The best results were obtained for hard contact lenses. There was perfect sterilization in this case. There were not perfect sterilization in some cases of soft contact lenses treatment. It may be caused by porous structure of the external layers of this material and limited thickness of the sterilization layer. (author)

Inductively coupled plasma-atomic emission spectroscopy

International Nuclear Information System (INIS)

Winge, R.K.; Fassel, V.A.; Peterson, V.J.; Floyd, M.A.

1985-01-01

This atlas of inductively coupled plasma-atomic emission spectroscopy records the spectra of the elements in a way that would reveal the general nature of the spectra, in all their simplicity or complexity; and offers a definitive summary of the most prominent spectral lines of the elements, i.e., those most likely to be useful for the determination of trace and ultratrace concentrations; it provides reliable estimates, based on the recorded experimental spectra, of the powers of detection of the listed prominent lines; and assesses the very important problem of spectral interferences. The atlas is composed of three main sections. Part I is concerned with the historical aspects of compilations of spectral information. Part II is based on 232 wavelength scans of 70 elements. Each of the wavelength scans covers an 80 nm spectral region. These scans allow a rapid comparison of the background and spectral line intensities emitted in the ICP and provide a ready means for identification of the most prominent lines of each element and for estimation of the trace element analytical capabilities of these lines. A listing of 973 prominent lines with associated detection limits is also presented. Part III addresses the problem of spectral interferences. On this topic a detailed collection of coincidence profiles is presented for 281 of the most prominent lines, each with profiles of ten of the most prevalent concomitants superimposed. (Auth.)

Development of Tokamak experiment technology - Study of ICRF coupling in the KAIST tokamak plasma

Energy Technology Data Exchange (ETDEWEB)

Choi, Duk In; Chang, Hang Young; Lee, Soon Chil; Kwon, Gi Chung; Seo, Sung Hun; Jeon, Sang Jin; Heo, Sung Hee; Heo, Eun Gi; Lee, Dae Hang; Lee, Chan Hee [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

1995-08-01

Research objectives are to design and fabricate antenna, measure the property of absorption transmitted to the plasma, and research the physical phenomena about the ICRF coupling. Main heating method is ohmic heating at the KAIST tokamak. So, the plasma current produced is more than 30 kA and, the loop voltage of the plasma is 2 {approx} 3V. The power of the plasma by ohmic heating is about 100 kW. Because the toroidal field is 5 {approx} 8 kG, it is needed RF system with more than 100 kW in 7 {approx} 15 MHz. In the first year a RF amplifier with 1 kW in 300 khz {approx} 35 MHz was bought. The manufacture of ICRF system will start from next years. In the research on antenna, we study the method how to measure electric field emitted from antenna using piezo elements. Experimentally, we obtain the results that the signal of piezo element is proportional to the square of electric field. In the next year, we will research the type of antenna subsequently. 28 refs., 3 tabs., 18 figs. (author)

Inductively coupled plasma etching of III-V antimonides in BCl{sub 3}/SiCl{sub 4} etch chemistry

Energy Technology Data Exchange (ETDEWEB)

Swaminathan, K. [Department of Electrical and Computer Engineering, University of Delaware, Newark, Delaware 19716 (United States)], E-mail: swaminak@ece.osu.edu; Janardhanan, P.E.; Sulima, O.V. [Department of Electrical and Computer Engineering, University of Delaware, Newark, Delaware 19716 (United States)

2008-10-01

Inductively coupled plasma etching of GaSb using BCl{sub 3}/SiCl{sub 4} etch chemistry has been investigated. The etch rates were studied as a function of bias power, inductively coupled plasma source power, plasma chemistry and chamber pressure. The etched surfaces remain smooth and stoichiometric over the entire range of plasma conditions investigated. The knowledge gained in etching GaSb was applied to etching AlGaAsSb and InGaAsSb in order to fabricate heterojunction phototransistors. As expected, InGaAsSb etch rate was much lower compared to the corresponding value for GaSb, mainly due to the relatively low volatility of indium chlorides. For a wide range of plasma conditions, the selectivity between GaSb and AlGaAsSb was close to unity, which is desirable for fabricating etched mirrors and gratings for Sb-based mid-infrared laser diodes. The surface roughness and the etch profile were examined for the etched GaSb, AlGaAsSb and InGaAsSb samples using scanning electron microscope. The high etch rates achieved ({approx} 4 {mu}m/min) facilitated deep etching of GaSb. A single layer, soft mask (AZ-4903 photoresist) was used to etch GaSb, with etch depth {approx} 90 {mu}m. The deep dry etching of GaSb has many important applications including etching substrate windows for backside-illuminated photodetectors for the mid-infrared wavelength range.

Aerosol detection efficiency in inductively coupled plasma mass spectrometry

Science.gov (United States)

Hubbard, Joshua A.; Zigmond, Joseph A.

2016-05-01

An electrostatic size classification technique was used to segregate particles of known composition prior to being injected into an inductively coupled plasma mass spectrometer (ICP-MS). Size-segregated particles were counted with a condensation nuclei counter as well as sampled with an ICP-MS. By injecting particles of known size, composition, and aerosol concentration into the ICP-MS, efficiencies of the order of magnitude aerosol detection were calculated, and the particle size dependencies for volatile and refractory species were quantified. Similar to laser ablation ICP-MS, aerosol detection efficiency was defined as the rate at which atoms were detected in the ICP-MS normalized by the rate at which atoms were injected in the form of particles. This method adds valuable insight into the development of technologies like laser ablation ICP-MS where aerosol particles (of relatively unknown size and gas concentration) are generated during ablation and then transported into the plasma of an ICP-MS. In this study, we characterized aerosol detection efficiencies of volatile species gold and silver along with refractory species aluminum oxide, cerium oxide, and yttrium oxide. Aerosols were generated with electrical mobility diameters ranging from 100 to 1000 nm. In general, it was observed that refractory species had lower aerosol detection efficiencies than volatile species, and there were strong dependencies on particle size and plasma torch residence time. Volatile species showed a distinct transition point at which aerosol detection efficiency began decreasing with increasing particle size. This critical diameter indicated the largest particle size for which complete particle detection should be expected and agreed with theories published in other works. Aerosol detection efficiencies also displayed power law dependencies on particle size. Aerosol detection efficiencies ranged from 10- 5 to 10- 11. Free molecular heat and mass transfer theory was applied, but

Fluid simulation of the phase-shift effect in hydrogen capacitively coupled plasmas: II. Radial uniformity of the plasma characteristics

International Nuclear Information System (INIS)

Zhang Yuru; Xu Xiang; Wang Younian; Bogaerts, Annemie

2012-01-01

A two-dimensional fluid model, including the full set of Maxwell equations, has been developed and applied to investigate the effect of a phase shift between two power sources on the radial uniformity of several plasma characteristics in a hydrogen capacitively coupled plasma. This study was carried out at various frequencies in the range 13.56-200 MHz. When the frequency is low, at 13.56 MHz, the plasma density is characterized by an off-axis peak when both power sources are in-phase (φ = 0), and the best radial uniformity is obtained at φ = π. This trend can be explained because the radial nonuniformity caused by the electrostatic edge effect can be effectively suppressed by the phase-shift effect at a phase difference equal to π. When the frequency rises to 60 MHz, the plasma density profiles shift smoothly from edge-peaked over uniform to centre-peaked as the phase difference increases, due to the pronounced standing-wave effect, and the best radial uniformity is reached at φ = 0.3π. At a frequency of 100 MHz, a similar behaviour is observed, except that the maximum of the plasma density moves again towards the radial edge at the reverse-phase case (φ = π), because of the dominant skin effect. When the frequency is 200 MHz, the bulk plasma density increases significantly with increasing phase-shift values, and a better uniformity is obtained at φ = 0.4π. This is because the density in the centre increases faster than at the radial edge as the phase difference rises, due to the increasing power deposition P z in the centre and the decreasing power density P r at the radial edge. As the phase difference increases to π, the maximum near the radial edge becomes obvious again. This is because the skin effect has a predominant influence on the plasma density under this condition, resulting in a high density at the radial edge. Moreover, the axial ion flux increases monotonically with phase difference, and exhibits similar profiles to the plasma density

Electrical description of a magnetic pole enhanced inductively coupled plasma source: Refinement of the transformer model by reverse electromagnetic modeling

International Nuclear Information System (INIS)

Meziani, T.; Colpo, P.; Rossi, F.

2006-01-01

The magnetic pole enhanced inductively coupled source (MaPE-ICP) is an innovative low-pressure plasma source that allows for high plasma density and high plasma uniformity, as well as large-area plasma generation. This article presents an electrical characterization of this source, and the experimental measurements are compared to the results obtained after modeling the source by the equivalent circuit of the transformer. In particular, the method applied consists in performing a reverse electromagnetic modeling of the source by providing the measured plasma parameters such as plasma density and electron temperature as an input, and computing the total impedance seen at the primary of the transformer. The impedance results given by the model are compared to the experimental results. This approach allows for a more comprehensive refinement of the electrical model in order to obtain a better fitting of the results. The electrical characteristics of the system, and in particular the total impedance, were measured at the inductive coil antenna (primary of the transformer). The source was modeled electrically by a finite element method, treating the plasma as a conductive load and taking into account the complex plasma conductivity, the value of which was calculated from the electron density and electron temperature measurements carried out previously. The electrical characterization of the inductive excitation source itself versus frequency showed that the source cannot be treated as purely inductive and that the effect of parasitic capacitances must be taken into account in the model. Finally, considerations on the effect of the magnetic core addition on the capacitive component of the coupling are made

UV and IR laser ablation for inductively coupled plasma mass spectrometry

International Nuclear Information System (INIS)

Smith, M.R.; Koppenaal, D.W.; Farmer, O.T.

1993-06-01

Laser ablation particle plume compositions are characterized using inductively coupled plasma mass spectrometry (ICP/MS). This study evaluates the mass response characteristics peculiar to ICP/MS detection as a function of laser fluence and frequency. Evaluation of the ICP/MS mass response allows deductions to be made concerning how representative the laser ablation produced particle plume composition is relative to the targeted sample. Using a black glass standard, elemental fractionation was observed, primarily for alkalis and other volatile elements. The extent of elemental fractionation between the target sample and the sampled plume varied significantly as a function of laser fluences and IR and UV laser frequency

A generalized electron energy probability function for inductively coupled plasmas under conditions of nonlocal electron kinetics

Science.gov (United States)

Mouchtouris, S.; Kokkoris, G.

2018-01-01

A generalized equation for the electron energy probability function (EEPF) of inductively coupled Ar plasmas is proposed under conditions of nonlocal electron kinetics and diffusive cooling. The proposed equation describes the local EEPF in a discharge and the independent variable is the kinetic energy of electrons. The EEPF consists of a bulk and a depleted tail part and incorporates the effect of the plasma potential, Vp, and pressure. Due to diffusive cooling, the break point of the EEPF is eVp. The pressure alters the shape of the bulk and the slope of the tail part. The parameters of the proposed EEPF are extracted by fitting to measure EEPFs (at one point in the reactor) at different pressures. By coupling the proposed EEPF with a hybrid plasma model, measurements in the gaseous electronics conference reference reactor concerning (a) the electron density and temperature and the plasma potential, either spatially resolved or at different pressure (10-50 mTorr) and power, and (b) the ion current density of the electrode, are well reproduced. The effect of the choice of the EEPF on the results is investigated by a comparison to an EEPF coming from the Boltzmann equation (local electron kinetics approach) and to a Maxwellian EEPF. The accuracy of the results and the fact that the proposed EEPF is predefined renders its use a reliable alternative with a low computational cost compared to stochastic electron kinetic models at low pressure conditions, which can be extended to other gases and/or different electron heating mechanisms.

Reduction of plyatomic ion interferences in indictively coupled plasma mass spectrometry with cryogenic desolvation

Energy Technology Data Exchange (ETDEWEB)

Alves, Luis C. [Iowa State Univ., Ames, IA (United States)

1993-09-01

A desolvation scheme for introducing aqueous and organic samples into an argon inductively coupled plasma is described; the aerosol generated by nebulizer is heated (+140 C) and cooled (-80 C) repeatedly, and the dried aerosol is then injected into the mass spectrometer. Polyatomic ions are greatly suppressed. This scheme was validated with analysis of seawater and urine reference samples. Finally, the removal of organic solvents by cryogenic desolvation was studied.

Collisionless coupling of a high- β expansion to an ambient, magnetized plasma. I. Rayleigh model and scaling

Science.gov (United States)

Bonde, Jeffrey

2018-04-01

The dynamics of a magnetized, expanding plasma with a high ratio of kinetic energy density to ambient magnetic field energy density, or β, are examined by adapting a model of gaseous bubbles expanding in liquids as developed by Lord Rayleigh. New features include scale magnitudes and evolution of the electric fields in the system. The collisionless coupling between the expanding and ambient plasma due to these fields is described as well as the relevant scaling relations. Several different responses of the ambient plasma to the expansion are identified in this model, and for most laboratory experiments, ambient ions should be pulled inward, against the expansion due to the dominance of the electrostatic field.

Determination of Ar metastable atom densities in Ar and Ar/H2 inductively coupled low-temperature plasmas

International Nuclear Information System (INIS)

Fox-Lyon, N; Knoll, A J; Oehrlein, G S; Franek, J; Demidov, V; Koepke, M; Godyak, V

2013-01-01

Ar metastable atoms are important energy carriers and surface interacting species in low-temperature plasmas that are difficult to quantify. Ar metastable atom densities (N Ar,m ) in inductively coupled Ar and Ar/H 2 plasmas were obtained using a model combining electrical probe measurements of electron density (N e ) and temperature (T e ), with analysis of spectrally resolved Ar plasma optical emission based on 3p → 1s optical emission ratios of the 419.8 nm line to the 420.1 nm line. We present the variation of N Ar,m as the Ar pressure and the addition of H 2 to Ar are changed comparatively to recent adsorption spectroscopy measurements. (paper)

A fully-implicit Particle-In-Cell Monte Carlo Collision code for the simulation of inductively coupled plasmas

Science.gov (United States)

Mattei, S.; Nishida, K.; Onai, M.; Lettry, J.; Tran, M. Q.; Hatayama, A.

2017-12-01

We present a fully-implicit electromagnetic Particle-In-Cell Monte Carlo collision code, called NINJA, written for the simulation of inductively coupled plasmas. NINJA employs a kinetic enslaved Jacobian-Free Newton Krylov method to solve self-consistently the interaction between the electromagnetic field generated by the radio-frequency coil and the plasma response. The simulated plasma includes a kinetic description of charged and neutral species as well as the collision processes between them. The algorithm allows simulations with cell sizes much larger than the Debye length and time steps in excess of the Courant-Friedrichs-Lewy condition whilst preserving the conservation of the total energy. The code is applied to the simulation of the plasma discharge of the Linac4 H- ion source at CERN. Simulation results of plasma density, temperature and EEDF are discussed and compared with optical emission spectroscopy measurements. A systematic study of the energy conservation as a function of the numerical parameters is presented.

Analysis of phosphorus herbicides by ion-pairing reversed-phase liquid chromatography coupled to inductively coupled plasma mass spectrometry with octapole reaction cell.

Science.gov (United States)

Sadi, Baki B M; Vonderheide, Anne P; Caruso, Joseph A

2004-09-24

A reversed phase ion-pairing high performance liquid chromatographic (RPIP-HPLC) method is developed for the separation of two phosphorus herbicides, Glufosinate and Glyphosate as well as Aminomethylphosphonic acid (AMPA), the major metabolite of Glyphosate. Tetrabutylammonium hydroxide is used as the ion-pairing reagent in conjunction with an ammonium acetate/acetic acid buffering system at pH 4.7. An inductively coupled plasma mass spectrometer (ICP-MS) is coupled to the chromatographic system to detect the herbicides at m/z = 31P. Historically, phosphorus has been recognized as one of the elements difficult to analyze in argon plasma. This is due to its relatively high ionization potential (10.5 eV) as well as the inherent presence of the polyatomic interferences 14N16O1H+ and 15N16O+ overlapping its only isotope at m/z = 31. An octapole reaction cell is utilized to minimize the isobaric polyatomic interferences and to obtain the highest signal-to-background ratio. Detection limits were found to be in the low ppt range (25-32 ng/l). The developed method is successfully applied to the analysis of water samples collected from the Ohio River and spiked with a standard compounds at a level of 20 microg/l.

A validated inductively coupled plasma mass spectrometry (ICP-MS) method for the quantification of total platinum content in plasma, plasma ultrafiltrate, urine and peritoneal fluid.

Science.gov (United States)

Lemoine, Lieselotte; Thijssen, Elsy; Noben, Jean-Paul; Adriaensens, Peter; Carleer, Robert; Speeten, Kurt Van der

2018-04-15

Oxaliplatin is a platinum (Pt) 1 containing antineoplastic agent that is applied in current clinical practice for the treatment of colon and appendiceal neoplasms. A fully validated, highly sensitive, high throughput inductively coupled plasma mass spectrometry (ICP-MS) method is provided to quantify the total Pt content in plasma, plasma ultrafiltrate, urine and peritoneal fluid. In this ICP-MS approach, the only step of sample preparation is a 1000-fold dilution in 0.5% nitric acid, allowing the analysis of 17 samples per hour. Detection of Pt was achieved over a linear range of 0.01-100 ng/mL. The limit of quantification was 18.0 ng/mL Pt in plasma, 8.0 ng/mL in ultrafiltrate and 6.1 ng/mL in urine and peritoneal fluid. The ICP-MS method was further validated for inter-and intraday precision and accuracy (≤15%), recovery, robustness and stability. Short-term storage of the biofluids, for 14 days, can be performed at -4 °C, -24 °C and -80 °C. As to long-term stability, up to 5 months, storage at -80 °C is encouraged. Furthermore, a timeline assessing the total and unbound Pt fraction in plasma and ultrafiltrate over a period of 45 h is provided. Following an incubation period of 5 h at 37 °C, 19-21% of Pt was recovered in the ultrafiltrate, emphasizing the extensive and rapid binding of oxaliplatin-derived Pt to plasma proteins. The described method can easily be implemented in a routine setting for pharmacokinetic studies in patients treated with oxaliplatin-based hyperthermic intraperitoneal perioperative chemotherapy. Copyright © 2018 Elsevier B.V. All rights reserved.

Radio frequency energy coupling to high-pressure optically pumped nonequilibrium plasmas

International Nuclear Information System (INIS)

Plonjes, Elke; Palm, Peter; Lee, Wonchul; Lempert, Walter R.; Adamovich, Igor V.

2001-01-01

This article presents an experimental demonstration of a high-pressure unconditionally stable nonequilibrium molecular plasma sustained by a combination of a continuous wave CO laser and a sub-breakdown radio frequency (rf) electric field. The plasma is sustained in a CO/N 2 mixture containing trace amounts of NO or O 2 at pressures of P=0.4 - 1.2atm. The initial ionization of the gases is produced by an associative ionization mechanism in collisions of two CO molecules excited to high vibrational levels by resonance absorption of the CO laser radiation with subsequent vibration-vibration (V-V) pumping. Further vibrational excitation of both CO and N 2 is produced by free electrons heated by the applied rf field, which in turn produces additional ionization of these species by the associative ionization mechanism. In the present experiments, the reduced electric field, E/N, is sufficiently low to preclude field-induced electron impact ionization. Unconditional stability of the resultant cold molecular plasma is enabled by the negative feedback between gas heating and the associative ionization rate. Trace amounts of nitric oxide or oxygen added to the baseline CO/N 2 gas mixture considerably reduce the electron - ion dissociative recombination rate and thereby significantly increase the initial electron density. This allows triggering of the rf power coupling to the vibrational energy modes of the gas mixture. Vibrational level populations of CO and N 2 are monitored by infrared emission spectroscopy and spontaneous Raman spectroscopy. The experiments demonstrate that the use of a sub-breakdown rf field in addition to the CO laser allows an increase of the plasma volume by about an order of magnitude. Also, CO infrared emission spectra show that with the rf voltage turned on the number of vibrationally excited CO molecules along the line of sight increase by a factor of 3 - 7. Finally, spontaneous Raman spectra of N 2 show that with the rf voltage the vibrational

Coupling of an ICRF compact loop antenna to H-mode plasmas in DIII-D

International Nuclear Information System (INIS)

Mayberry, M.J.; Baity, F.W.; Hoffman, D.J.; Luxon, J.L.; Owens, T.L.; Prater, R.

1987-01-01

Low power coupling tests have been carried out with a prototype ICRF compact loop antenna on the DIII-D tokamak. During neutral-beam-heated L-mode discharges the antenna loading is typically R≅1-2Ω for an rf frequency of 32 MHz (B/sub T/ = 21 kG, ω = 2Ω/sub D/(0)). When a transition into the H-mode regime of improved confinement occurs, the loading drops to R≅0.5-1.0Ω. During ELMs, transient increases in loading up to several Ohms are observed. The apparent sensitivity of ICRF antenna coupling to changes in the edge plasma profiles associated with the H-mode regime could have important implications for the design of future high power systems

Analysis of cobalt, tantalum, titanium, vanadium and chromium in tungsten carbide by inductively coupled plasma-optical emission spectrometry

CSIR Research Space (South Africa)

Archer, M

2003-12-01

Full Text Available Inductively coupled plasma optical emission spectroscopy (ICP-OES) was used to measure the concentrations of cobalt, tantalum, titanium, vanadium and chromium in solutions of tungsten carbide. The main advantage of the method described here lies...

Inductively coupled plasma--atomic emission spectrometry: trace elements in oil matrices

Energy Technology Data Exchange (ETDEWEB)

Peterson, Charlie Albert [Iowa State Univ., Ames, IA (United States)

1977-12-01

The simultaneous determination of up to 20 trace elements in various oil matrices by inductively coupled plasma-atomic emission spectrometry is reported. The oil matrices investigated were lubricating oils (for wear metals), fuel oil, centrifuged coal liquefaction product, crude soybean oil, and commercial edible oils. The samples were diluted with appropriate organic solvents and injected into the plasma as an aerosol generated by a pneumatic nebulization technique. Detection limits of the 28 elements studied ranged from 0.0006 to 9 μg/g with the majority falling in the 0.01 to 0.1 μg/g range. Analytical calibration curves were linear over at least two orders of magnitude and for some elements this linearity extended over 4.5 orders of magnitude. Relevant data on precision and accuracy are included. Because metals often occur as particles in lubricating oil and coal liquefaction products, the effect of particles on the analytical results was examined. Wear metal particles in used oil did not appear to affect the analytical results. However, incomplete recovery relative to organometallic reference solutions was obtained for iron particles with a nominal mean diameter of 3.0 μm suspended in oil. It was shown that the following factors contributed to incomplete recovery for the particles: settling of the suspended particles in the flask, a difference in nebulization efficiency between particle suspensions and organometallic solutions, and indications of incomplete vaporization of the larger particles in the plasma.

Measurements of energy distribution and thrust for microwave plasma coupling of electrical energy to hydrogen for propulsion

Science.gov (United States)

Morin, T.; Chapman, R.; Filpus, J.; Hawley, M.; Kerber, R.; Asmussen, J.; Nakanishi, S.

1982-01-01

A microwave plasma system for transfer of electrical energy to hydrogen flowing through the system has potential application for coupling energy to a flowing gas in the electrothermal propulsion concept. Experimental systems have been designed and built for determination of the energy inputs and outputs and thrust for the microwave coupling of energy to hydrogen. Results for experiments with pressure in the range 100 microns-6 torr, hydrogen flow rate up to 1000 micronmoles/s, and total absorbed power to 700 w are presented.

Atlas of Atomic Spectral Lines of Neptunium Emitted by Inductively Coupled Plasma

Energy Technology Data Exchange (ETDEWEB)

DeKalb, E.L. and Edelson, M. C.

1987-08-01

Optical emission spectra from high-purity Np-237 were generated with a glovebox-enclosed inductively coupled plasma (ICP) source. Spectra covering the 230-700 nm wavelength range are presented along with general commentary on the methodology used in collecting the data. The Ames Laboratory Nuclear Safeguards and Security Program has been charged with the task of developing optical spectroscopic methods to analyze the composition of spent nuclear fuels. Such materials are highly radioactive even after prolonged 'cooling' and are chemically complex. Neptunium (Np) is a highly toxic by-product of nuclear power generation and is found, in low abundance, in spent nuclear fuels. This atlas of the optical emission spectrum of Np, as produced by an inductively coupled plasma (ICP) spectroscopic source, is part of a general survey of the ICP emission spectra of the actinide elements. The ICP emission spectrum of the actinides originates almost exclusively from the electronic relaxation of excited, singly ionized species. Spectral data on the Np ion emission spectrum (i.e., the Np II spectrum) have been reported by Tomkins and Fred [1] and Haaland [2]. Tomkins and Fred excited the Np II spectrum with a Cu spark discharge and identified 114 Np lines in the 265.5 - 436.3 nm spectral range. Haaland, who corrected some spectral line misidentifications in the work of Tomkins and Fred, utilized an enclosed Au spark discharge to excite the Np II spectrum and reported 203 Np lines within the 265.4 - 461.0 nm wavelength range.

Polymerization by plasma of trichloroethylene by means of resistive and inductive coupling; Polimerizacion por plasmas de tricloroetileno por medio de acoplamiento resistivo e inductivo

Energy Technology Data Exchange (ETDEWEB)

Vasquez, M.; Cruz, G.; Olayo, M.G. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Timoshina, T. [IPN, ESIQIE, 07738 Mexico D.F. (Mexico); Morales, J.; Olayo, R. [UAM-I, 09340 Mexico D.F. (Mexico)

2004-07-01

It was carried out the polymerization for plasma of the trichloroethylene by means of two types of coupling, resistive and inductive with the objective of studying the structure, morphology and the electric properties of the polymers obtained under these conditions. The structure and morphology of the polymers were studied by means of EDS and FT-IR spectroscopies. (Author)

Parálisis cerebral :

OpenAIRE

Cabrero Izquierdo, María del Carmen

2012-01-01

Se aborda el tema de la parálisis cerebral definiendo qué es, clasificando los tipos de parálisis dependiendo de la afectación y las características principales. Se explican algunos de sus tratamientos, se dan sistemas alternativos y/o aumentativos de comunicación para un alumno con PC (parálisis cerebral).

Formation Of Carbon Oxides In CH4/O2 Plasmas Produced By Inductively Coupled RF Discharges At Low Pressure

International Nuclear Information System (INIS)

Moeller, Ivonne; Soltwisch, Henning

2003-01-01

The formation of CO and CO2 has been studied in inductively coupled rf (13.56 MHz) discharges with varied mixtures of CH4 and O2 as feed gases at a total pressure of 10 Pa, flow rates of <10 sccm, and input powers of <500 W. The primary diagnostic tool has been TDLAS (tunable diode laser absorption spectroscopy) to measure absolute concentrations of molecular species as well as their kinetic and rovibrational temperatures. Of particular interest is the sudden transition between different modes of power coupling (capacitive and inductive mode, resp.) and the related changes of the plasma composition. We have found that the power threshold for this transition exhibits a clear hysteresis and depends on the oxygen content. Comparing the ratio of the CO- and CO2-concentrations in capacitive mode with corresponding data from a parallel-plate discharge, clear differences have been observed. The findings can partly be explained on the basis of plasma-chemical reaction chains using tabulated cross-sections in combination with estimations of the electron energy distribution function. Some observations (as, e.g. the presence of CO in inductively coupled plasmas that are fed by pure oxygen) cannot be understood from volume reactions only but point to an important role of surface processes, which depend on the materials of the discharge chamber and on its history and cleaning method

Study of hard diamond-like carbon films deposited in an inductively coupled plasma source

International Nuclear Information System (INIS)

Yu Shiji; Ma Tengcai

2003-01-01

Chemical vapor deposition of the hard diamond-like carbon (DLC) films was achieved using an inductively coupled plasma source (ICPS). The microscopy, microhardness, deposition rate and structure characteristic of the DLC films were analyzed. It is shown that the ICPS is suitable for the hard DLC film deposition at relatively low substrate negative bias voltage, and the substrate negative bias voltage greatly affects chemical vapor deposition of the DLC film and its quality

Integrated CFD Model for Nanoparticle Production in Inductively Coupled Plasma Reactor: Implementation and Application

OpenAIRE

Benros Santos Lopes, Silvania

2016-01-01

Nanoparticles represent a very exciting new area of research. Their small size, ranging from several nanometers to tens of nanometers, is responsible for many changes in the structural, thermal, electromagnetic, optical and mechanical properties in comparison with the bulk solid of the same materials. However, promoting the use of such material requires well-controlled synthesis techniques to be developed. Inductively coupled thermal plasma (ICTP) reactors have been shown to offer unique adva...

Determination of Dibutyltin in Sediments Using Isotope Dilution Liquid Chromatography-Inductively Coupled Plasma Mass Spectrometry

International Nuclear Information System (INIS)

Yim, Yong Hyeon; Park, Ji Youn; Han, Myung Sub; Park, Mi Kyung; Kim, Byung Joo; Lim, Young Ran; Hwang, Eui Jin; So, Hun Young

2005-01-01

A method is described for the determination of dibutyltin (DBT) in sediment by isotope dilution using liquid chromatography inductively-coupled plasma/mass spectrometry (LC-ICP/MS). To achieve the highest accuracy and precision, special attentions are paid in optimization and evaluation of overall processes of the analysis including extraction of analytes, characterization of the standards used for calibration and LC-ICP/MS conditions. An approach for characterization of natural abundance DBT standard has been developed by combining inductively-coupled plasma/optical emission spectrometry (ICP/OES) and LC-ICP/MS for the total Sn assay and the analysis of Sn species present as impurities, respectively. An excellent LC condition for separation of organotin species was found, which is suitable for simultaneous DBT and tributyltin (TBT) analysis as well as impurity analysis of DBT standards. Microwave extraction condition was also optimized for high efficiency while preventing species transformation. The present method determines the amount contents of DBT in sediments with expanded uncertainty of less than 5% and its result shows high degree of equivalence with reference values of an international inter-comparison and a certified reference material (CRM) within stated uncertainties

Determination of Dibutyltin in Sediments Using Isotope Dilution Liquid Chromatography-Inductively Coupled Plasma Mass Spectrometry

Energy Technology Data Exchange (ETDEWEB)

Yim, Yong Hyeon; Park, Ji Youn; Han, Myung Sub; Park, Mi Kyung; Kim, Byung Joo; Lim, Young Ran; Hwang, Eui Jin; So, Hun Young [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of)

2005-03-15

A method is described for the determination of dibutyltin (DBT) in sediment by isotope dilution using liquid chromatography inductively-coupled plasma/mass spectrometry (LC-ICP/MS). To achieve the highest accuracy and precision, special attentions are paid in optimization and evaluation of overall processes of the analysis including extraction of analytes, characterization of the standards used for calibration and LC-ICP/MS conditions. An approach for characterization of natural abundance DBT standard has been developed by combining inductively-coupled plasma/optical emission spectrometry (ICP/OES) and LC-ICP/MS for the total Sn assay and the analysis of Sn species present as impurities, respectively. An excellent LC condition for separation of organotin species was found, which is suitable for simultaneous DBT and tributyltin (TBT) analysis as well as impurity analysis of DBT standards. Microwave extraction condition was also optimized for high efficiency while preventing species transformation. The present method determines the amount contents of DBT in sediments with expanded uncertainty of less than 5% and its result shows high degree of equivalence with reference values of an international inter-comparison and a certified reference material (CRM) within stated uncertainties.

Minimally-invasive Laser Ablation Inductively Coupled Plasma Mass Spectrometry analysis of model ancient copper alloys

Energy Technology Data Exchange (ETDEWEB)

Walaszek, Damian [University of Warsaw, Faculty of Chemistry, Biological and Chemical Research Centre, Żwirki i Wigury 101, 02-089 Warszawa (Poland); Laboratory for Analytical Chemistry, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland); Senn, Marianne; Wichser, Adrian [Laboratory for Analytical Chemistry, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland); Faller, Markus [Laboratory for Jointing Technology and Corrosion, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland); Wagner, Barbara; Bulska, Ewa [University of Warsaw, Faculty of Chemistry, Biological and Chemical Research Centre, Żwirki i Wigury 101, 02-089 Warszawa (Poland); Ulrich, Andrea [Laboratory for Analytical Chemistry, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf (Switzerland)

2014-09-01

This work describes an evaluation of a strategy for multi-elemental analysis of typical ancient bronzes (copper, lead bronze and tin bronze) by means of laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS).The samples originating from archeological experiments on ancient metal smelting processes using direct reduction in a ‘bloomery’ furnace as well as historical casting techniques were investigated with the use of the previously proposed analytical procedure, including metallurgical observation and preliminary visual estimation of the homogeneity of the samples. The results of LA-ICPMS analysis were compared to the results of bulk composition obtained by X-ray fluorescence spectrometry (XRF) and by inductively coupled plasma mass spectrometry (ICPMS) after acid digestion. These results were coherent for most of the elements confirming the usefulness of the proposed analytical procedure, however the reliability of the quantitative information about the content of the most heterogeneously distributed elements was also discussed in more detail. - Highlights: • The previously proposed procedure was evaluated by analysis of model copper alloys. • The LA-ICPMS results were comparable to the obtained by means of XRF and ICPMS. • LA-ICPMS results indicated the usefulness of the proposed analytical procedure.

Intact and cleaved plasma soluble urokinase receptor in patients with metastatic colorectal cancer treated with oxaliplatin with or without cetuximab

DEFF Research Database (Denmark)

Tarpgaard, Line Schmidt; Christensen, Ib Jarle; Høyer-Hansen, Gunilla

2015-01-01

) in a ligand-independent manner. The purpose of the study was to evaluate whether plasma soluble intact and cleaved uPAR(I-III)+(II-III) levels could identify a subpopulation of patients with metastatic colorectal cancer (mCRC) where treatment with cetuximab would have a beneficial effect. Plasma samples were...... available from 453 patients treated in the NORDIC VII study. Patients were randomized between FLOX and FLOX + cetuximab. The levels of uPAR(I-III)+(II-III) were determined by time-resolved fluorescence immunoassay. We demonstrated that higher baseline plasma uPAR(I-III)+(II-III) levels were significantly...... with FLOX + cetuximab as compared to patients with KRAS wild-type and high levels of suPAR. These results thus support the preclinical findings and should be further tested in an independent clinical data set....

Multi-elemental analysis of aqueous geochemical samples by quadrupole inductively coupled plasma-mass spectrometry (ICP-MS)

Science.gov (United States)

Wolf, Ruth E.; Adams, Monique

2015-01-01

Typically, quadrupole inductively coupled plasma-mass spectrometry (ICP-MS) is used to determine as many as 57 major, minor, and trace elements in aqueous geochemical samples, including natural surface water and groundwater, acid mine drainage water, and extracts or leachates from geological samples. The sample solution is aspirated into the inductively coupled plasma (ICP) which is an electrodeless discharge of ionized argon gas at a temperature of approximately 6,000 degrees Celsius. The elements in the sample solution are subsequently volatilized, atomized, and ionized by the ICP. The ions generated are then focused and introduced into a quadrupole mass filter which only allows one mass to reach the detector at a given moment in time. As the settings of the mass analyzer change, subsequent masses are allowed to impact the detector. Although the typical quadrupole ICP-MS system is a sequential scanning instrument (determining each mass separately), the scan speed of modern instruments is on the order of several thousand masses per second. Consequently, typical total sample analysis times of 2–3 minutes are readily achievable for up to 57 elements.

Simultaneous electrothermal vaporization and nebulizer sample introduction system for inductively coupled plasma mass spectrometry

International Nuclear Information System (INIS)

Arnquist, Isaac J.; Kreschollek, Thomas E.; Holcombe, James A.

2011-01-01

The novel analytical application of the combination of an inline electrothermal vaporization (ETV) and nebulization source for inductively coupled plasma mass spectrometry (ICP-MS) has been studied. Wet plasma conditions are sustained during ETV introduction by 200 mL/min gas flow through the nebulizer, which is merged with the ETV transport line at the torch. The use of a wet plasma with ETV introduction avoided the need to change power settings and torch positions that normally accompany a change from wet to dry plasma operating conditions. This inline-ETV source is shown to have good detection limits for a variety of elements in both HNO 3 and HCl matrices. Using the inline-ETV source, improved limits of detection (LOD) were obtained for elements typically suppressed by polyatomic interferences using a nebulizer. Specifically, improved LODs for 51 V and 53 Cr suffering from Cl interferences ( 51 ClO + and 53 ClO + respectively) in a 1% HCl matrix were obtained using the inline-ETV source. LODs were improved by factors of 65 and 22 for 51 V and 53 Cr, respectively, using the inline-ETV source compared to a conventional concentric glass nebulizer. For elements without polyatomic interferences, LODs from the inline-ETV were comparable to conventional dry plasma ETV-ICP time-of-flight mass spectrometry results. Lastly, the inline-ETV source offers a simple means of changing from nebulizer introduction to inline-ETV introduction without extinguishing the plasma. This permits, for example, the use of the time-resolved ETV-ICP-MS signals to distinguish between an analyte ion and polyatomic isobar.

Nonlinear Raman scattering behavior with Langmuir and sound waves coupling in a homogeneous plasma

International Nuclear Information System (INIS)

Bonnaud, G.; Pesme, D.; Pellat, R.

1990-01-01

By means of wave-coupling simulations, the typical nonlinear evolution of stimulated Raman scattering (SRS) is investigated in a homogeneous sub-quarter-critical plasma for present-day low laser irradiances and kilo-electron-volt electron temperatures. The decrease of the Langmuir energy observed after the SRS growth is found to be basically the result of the electrostatic decay instability (EDI) onset, which generates a high-amplitude ion-acoustic wave. The resulting strong modulation of the plasma density causes a conversion process that transforms the initial one-wave-vector Langmuir wave driven by SRS into a Bloch wave and induces SRS detuning and larger damping. The conditions involved herein have allowed isolation of these processes from the modulational instability; in addition, the Langmuir collapse is found not to occur owing to the high electron temperature

Inductively coupled plasma mass spectrometry in the analysis of biological samples and pharmaceutical drugs

Science.gov (United States)

Ossipov, K.; Seregina, I. F.; Bolshov, M. A.

2016-04-01

Inductively coupled plasma mass spectrometry (ICP-MS) is widely used in the analysis of biological samples (whole blood, serum, blood plasma, urine, tissues, etc.) and pharmaceutical drugs. The shortcomings of this method related to spectral and non-spectral interferences are manifested in full measure in determination of the target analytes in these complex samples strongly differing in composition. The spectral interferences are caused by similarity of masses of the target component and sample matrix components. Non-spectral interferences are related to the influence of sample matrix components on the physicochemical processes taking place during formation and transportation of liquid sample aerosols into the plasma, on the value and spatial distribution of plasma temperature and on the transmission of the ion beam from the interface to mass spectrometer detector. The review is devoted to analysis of different mechanisms of appearance of non-spectral interferences and to ways for their minimization or elimination. Special attention is paid to the techniques of biological sample preparation, which largely determine the mechanisms of the influence of sample composition on the results of element determination. The ways of lowering non-spectral interferences by instrumental parameter tuning and application of internal standards are considered. The bibliography includes 189 references.

Plasma-related matrix effects in inductively coupled plasma--atomic emission spectrometry by group I and group II matrix-elements

International Nuclear Information System (INIS)

Chan, George C.-Y.; Chan, W.-T.

2003-01-01

The effects of Na, K, Ca and Ba matrices on the plasma excitation conditions in inductively coupled plasma-atomic emission spectrometry (ICP-AES) were studied. Normalized relative intensity was used to indicate the extent of the plasma-related matrix effects. The group I matrices have no effects on the plasma excitation conditions. In contrast, the group II matrices depress the normalized relative intensities of some spectral lines. Specifically, the Group II matrices have no effects on the normalized relative intensity of atomic lines of low upper energy level (soft lines), but reduce the normalized relative intensity of some ionic lines and atomic lines of high energy level (hard lines). The Group II matrices seem to shift the Saha balance of the analytes only; no shift in the Boltzmann balance was observed experimentally. Moreover, for some ionic lines with sum of ionization and excitation potentials close to the ionization potential of argon (15.75 eV), the matrix effect is smaller than other ionic lines of the same element. The reduced matrix effects may be attributed qualitatively to charge transfer excitation mechanism of these ionic lines. Charge transfer reaction renders ionic emission lines from the quasi-resonant levels similar in characteristics of atomic lines. The contribution of charge transfer relative to excitation by other non-specific excitation mechanisms (via Saha balance and Boltzmann balance) determines the degree of atomic behavior of a quasi-resonant level. A significant conclusion of this study is that plasma-related matrix effect depends strongly on the excitation mechanism of a spectral line. Since, in general, more than one excitation mechanism may contribute to the overall excitation of an emission line, the observed matrix effects reflect the sum of the effects due to individual excitation mechanisms. Excitation mechanisms, in addition to the often-used total excitation energy, should be considered in matrix effect studies

Optoelectronic properties of Black-Silicon generated through inductively coupled plasma (ICP) processing for crystalline silicon solar cells

Energy Technology Data Exchange (ETDEWEB)

Hirsch, Jens, E-mail: J.Hirsch@emw.hs-anhalt.de [Anhalt University of Applied Sciences, Faculty EMW, Bernburger Str. 55, DE-06366 Köthen (Germany); Fraunhofer Center for Silicon Photovoltaics CSP, Otto-Eißfeldt-Str. 12, DE-06120 Halle (Saale) (Germany); Gaudig, Maria; Bernhard, Norbert [Anhalt University of Applied Sciences, Faculty EMW, Bernburger Str. 55, DE-06366 Köthen (Germany); Lausch, Dominik [Fraunhofer Center for Silicon Photovoltaics CSP, Otto-Eißfeldt-Str. 12, DE-06120 Halle (Saale) (Germany)

2016-06-30

Highlights: • Fabrication of black silicon through inductively coupled plasma (ICP) processing. • Suppressed formation a self-bias and therefore a reduced ion bombardment of the silicon sample. • Reduction of the average hemispherical reflection between 300 and 1120 nm up to 8% within 5 min ICP process time. • Reflection is almost independent of the angle of incidence up to 60°. • 2.5 ms effective lifetime at 10{sup 15} cm{sup −3} MCD after ALD Al{sub 2}O{sub 3} surface passivation. - Abstract: The optoelectronic properties of maskless inductively coupled plasma (ICP) generated black silicon through SF{sub 6} and O{sub 2} are analyzed by using reflection measurements, scanning electron microscopy (SEM) and quasi steady state photoconductivity (QSSPC). The results are discussed and compared to capacitively coupled plasma (CCP) and industrial standard wet chemical textures. The ICP process forms parabolic like surface structures in a scale of 500 nm. This surface structure reduces the average hemispherical reflection between 300 and 1120 nm up to 8%. Additionally, the ICP texture shows a weak increase of the hemispherical reflection under tilted angles of incidence up to 60°. Furthermore, we report that the ICP process is independent of the crystal orientation and the surface roughness. This allows the texturing of monocrystalline, multicrystalline and kerf-less wafers using the same parameter set. The ICP generation of black silicon does not apply a self-bias on the silicon sample. Therefore, the silicon sample is exposed to a reduced ion bombardment, which reduces the plasma induced surface damage. This leads to an enhancement of the effective charge carrier lifetime up to 2.5 ms at 10{sup 15} cm{sup −3} minority carrier density (MCD) after an atomic layer deposition (ALD) with Al{sub 2}O{sub 3}. Since excellent etch results were obtained already after 4 min process time, we conclude that the ICP generation of black silicon is a promising technique

Multielemental analyses of tree rings by inductively coupled plasma mass spectrometry

International Nuclear Information System (INIS)

Hall, G.S.

1990-01-01

Inductively coupled plasma mass spectrometry (ICP-MS) was evaluated for major, minor, trace, and ultra-trace elemental analyses of individual tree rings. The samples were obtained from an old-growth Douglas fir growing near Mount St. Helens volcano, and from trees at various other North American sites. Eightly percent of elements from Li to U had detection limits in the solid (wood) below 8.0 ng g -1 . Two anomalous peaks occur in Mount St. Helens samples at A.D. 1478 and 1490 that closely correlate with past eruptions of the volcano. These results show that ICP-MS is a rapid and sensitive analytical method for multielemental analyses of individual tree rings. (author) 16 refs.; 2 figs.; 2 tabs

Hyphenation of ultra performance liquid chromatography (UPLC) with inductively coupled plasma mass spectrometry (ICP-MS) for fast analysis of bromine containing preservatives

DEFF Research Database (Denmark)

Bendahl, Lars; Hansen, Steen Honoré; Gammelgaard, Bente

2006-01-01

Ultra performance liquid chromatography (UPLC) was coupled to inductively coupled plasma mass spectrometry (ICP-MS) for fast analysis of three bromine-containing preservatives, monitoring the 79Br and 81Br isotopes simultaneously. Due to the efficiency of the 1.7 microm column packing material, t...... analysis of bromine-containing preservatives in commercially available cosmetic products.......Ultra performance liquid chromatography (UPLC) was coupled to inductively coupled plasma mass spectrometry (ICP-MS) for fast analysis of three bromine-containing preservatives, monitoring the 79Br and 81Br isotopes simultaneously. Due to the efficiency of the 1.7 microm column packing material...... at an intermediate and at a high linear velocity. The precision was better than 2.2% R.S.D. and regression analysis showed that a linear response was achieved at both flow rates (R2 > 0.9993, n = 36). The analysis time was less than 4.5 min at a flow rate of 50 microL min(-1) and limits of detection...

Determination of rare earth elements in tomato plants by inductively coupled plasma mass spectrometry techniques.

Science.gov (United States)

Spalla, S; Baffi, C; Barbante, C; Turetta, C; Turretta, C; Cozzi, G; Beone, G M; Bettinelli, M

2009-10-30

In recent years identification of the geographical origin of food has grown more important as consumers have become interested in knowing the provenance of the food that they purchase and eat. Certification schemes and labels have thus been developed to protect consumers and genuine producers from the improper use of popular brand names or renowned geographical origins. As the tomato is one of the major components of what is considered to be the healthy Mediterranean diet, it is important to be able to determine the geographical origin of tomatoes and tomato-based products such as tomato sauce. The aim of this work is to develop an analytical method to determine rare earth elements (RRE) for the control of the geographic origin of tomatoes. The content of REE in tomato plant samples collected from an agricultural area in Piacenza, Italy, was determined, using four different digestion procedures with and without HF. Microwave dissolution with HNO3 + H2O2 proved to be the most suitable digestion procedure. Inductively coupled plasma quadrupole mass spectrometry (ICPQMS) and inductively coupled plasma sector field plasma mass spectrometry (ICPSFMS) instruments, both coupled with a desolvation system, were used to determine the REE in tomato plants in two different laboratories. A matched calibration curve method was used for the quantification of the analytes. The detection limits (MDLs) of the method ranged from 0.03 ng g(-1) for Ho, Tm, and Lu to 2 ng g(-1) for La and Ce. The precision, in terms of relative standard deviation on six replicates, was good, with values ranging, on average, from 6.0% for LREE (light rare earth elements) to 16.5% for HREE (heavy rare earth elements). These detection limits allowed the determination of the very low concentrations of REE present in tomato berries. For the concentrations of REE in tomato plants, the following trend was observed: roots > leaves > stems > berries. Copyright 2009 John Wiley & Sons, Ltd.

Magnetic fields and uniformity of radio frequency power deposition in low-frequency inductively coupled plasmas with crossed internal oscillating currents

DEFF Research Database (Denmark)

Tsakadze, Erekle; Ostrikov, K.N.; Tsakadze, Z.L.

2004-01-01

) discharge modes using two miniature magnetic probes. It is shown that the radial uniformity and depth of the rf power deposition can be improved as compared with conventional sources of inductively coupled plasmas with external flat spiral ("pancake") antennas. Relatively deeper rf power deposition...... in the plasma source results in more uniform profiles of the optical emission intensity, which indicates on the improvement of the plasma uniformity over large chamber volumes. The results of the numerical modeling of the radial magnetic field profiles are found in a reasonable agreement with the experimental...

The Efficiency of Quartz Particles Evaporation in the Argon Plasma Flow of the RF Inductively Coupled Plasma Torch

Directory of Open Access Journals (Sweden)

Yu. M. Grishin

2017-01-01

Full Text Available Owing to high-power density and high-purity plasma, a RF inductively coupled plasma torch (ICPT is widely used both in research laboratory and in industry. The potential RF ICPT application areas are powders spheroidisation, waste treatment, thermal spraying, etc.In the last decade the investigation was focused on the treatment processes of quartz into polycrystalline silicon. An analysis of these results has shown that the increasing productivity and producing high-purity silicon can be achieved only when using the electrodeless radio-frequency induction plasma torches and in case the optimum conditions for evaporation of SiO2solid particles are realized.Optimization of the RF ICPT design and power parameters calls for a wide range of computational studies. In spite of the fact that to date a large number of efforts to calculate the evaporation efficiency of powder materials have been made, a number of issues, as applied to the problem of obtaining silicon, require further research.In this paper, we present the results of a two-dimensional numerical simulation of the heating and evaporation of quartz particles in the RF ICPT channel with axial flow of gases. The main aim is to determine how the axial position of the central tube (through which the particles are injected into the discharge zone, the dispersion of the quartz powder, the amplitude of the discharge current (and, respectively, flow regimes impact on the evaporation efficiency of quartz particles.The paper presented the numerical modeling results of heating and evaporation processes of quartz particles supplied by transporting gas to the RF ICPT channel with axial gas flow (argon. Defined the impact of the axial position of the central tube, the plasma flow regime, the discharge current, the flow rate of transporting gas, and other parameters on the evaporation efficiency of quartz particles.It is shown that the evaporation efficiency of particles reaches its maximum when their

Theoretical and experimental studies of a planar inductive coupled rf plasma source as the driver in simulator facility (ISTAPHM) of interactions of waves with the edge plasma on tokamaks

Science.gov (United States)

Ghanei, V.; Nasrabadi, M. N.; Chin, O.-H.; Jayapalan, K. K.

2017-11-01

This research aims to design and build a planar inductive coupled RF plasma source device which is the driver of the simulator project (ISTAPHM) of the interactions between ICRF Antenna and Plasma on tokamak by using the AMPICP model. For this purpose, a theoretical derivation of the distribution of the RF magnetic field in the plasma-filled reactor chamber is presented. An experimental investigation of the field distributions is described and Langmuir measurements are developed numerically. A comparison of theory and experiment provides an evaluation of plasma parameters in the planar ICP reactor. The objective of this study is to characterize the plasma produced by the source alone. We present the results of the first analysis of the plasma characteristics (plasma density, electron temperature, electron-ion collision frequency, particle fluxes and their velocities, stochastic frequency, skin depth and electron energy distribution functions) as function of the operating parameters (injected power, neutral pressure and magnetic field) as measured with fixed and movable Langmuir probes. The plasma is currently produced only by the planar ICP. The exact goal of these experiments is that the produced plasma by external source can exist as a plasma representative of the edge of tokamaks.

Application of femtosecond laser ablation inductively coupled plasma mass spectrometry for quantitative analysis of thin Cu(In,Ga)Se{sub 2} solar cell films

Energy Technology Data Exchange (ETDEWEB)

Lee, Seokhee [School of Mechatronics, Gwangju Institute of Science and Technology, 1 Oryong-dong, Buk-gu, Gwangju 500-712 (Korea, Republic of); Gonzalez, Jhanis J. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Applied Spectra Inc., 46665 Fremont Boulevard, Fremont, CA 94538 (United States); Yoo, Jong H. [Applied Spectra Inc., 46665 Fremont Boulevard, Fremont, CA 94538 (United States); Chirinos, Jose R. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Facultad de Ciencias, Universidad Central de Venezuela, Caracas 1041A (Venezuela, Bolivarian Republic of); Russo, Richard E. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Applied Spectra Inc., 46665 Fremont Boulevard, Fremont, CA 94538 (United States); Jeong, Sungho, E-mail: shjeong@gist.ac.kr [School of Mechatronics, Gwangju Institute of Science and Technology, 1 Oryong-dong, Buk-gu, Gwangju 500-712 (Korea, Republic of)

2015-02-27

This work reports that the composition of Cu(In,Ga)Se{sub 2} (CIGS) thin solar cell films can be quantitatively predicted with high accuracy and precision by femtosecond laser ablation-inductively coupled plasma-mass spectrometry (fs-LA-ICP-MS). It is demonstrated that the results are strongly influenced by sampling conditions during fs-laser beam (λ = 1030 nm, τ = 450 fs) scanning on the CIGS surface. The fs-LA-ICP-MS signals measured at optimal sampling conditions generally provide a straight line calibration with respect to the reference concentrations measured by inductively coupled plasma optical emission spectroscopy (ICP-OES). The concentration ratios predicted by fs-LA-ICP-MS showed high accuracy, to 95–97% of the values measured with ICP-OES, for Cu, In, Ga, and Se elements. - Highlights: • Laser ablation inductively coupled plasma mass spectrometry of thin film is reported. • Concentration ratio prediction with a confidence level of 95–97% is achieved. • Quantitative determination of composition is demonstrated.

Top down viewing of the inductively coupled plasma using a dual grating, direct reading spectrograph and an all mirror optical system

International Nuclear Information System (INIS)

Apel, C.T.; Duchane, D.V.; Palmer, B.A.

1980-01-01

Using an all-mirror optical system, an inductively coupled plasma is viewed top down and the light is directed to a dual grating, direct reading spectrograph. Top down viewing of the plasma, with masking of the image of the argon plasma torus at the spectrograph entrance slit, significantly reduces background signal from the source and permits the use of the depth of field of the optical system to achieve compromise conditions for viewing the plasma. Light from the plasma source is introduced to the optical system by means of a mirror situated directly over the plasma. The system is exhausted in such a way that cool air flowing past the mirror forms a thermal barrier between the mirror and the plasma. Elements such as copper and lead have atomic and ionic lines which tend to exhibit self absorption when viewed top down through the cooler ground state atoms in the plume of the plasma. One of the approaches to this problem is to shear off the plume of the plasma with a jet of air directed across the tip of the plasma. A second approach is to make use of the dual grating, direct reading spectrograph and real-time computer system which easily permits the setting of alternate lines for each element so that self absorption and matrix effects are minimized. The design of the dual-grating, direct-reading spectrograph allows for the mounting of more than 200 13-mm-dia photomultiplier tubes along the focal curves. In an effort to demonstrate the use of fiber optics as a viable technique for the closer placement of exit slits, a red sensitive photomultiplier tube was coupled with a 30-cm fiber-optic ribbon to detect light from the Li 670.784 nm line on the focal curve. It was successful and had the added advantages of absorbing second-order ultraviolet light

Self-consistent simulation study on magnetized inductively coupled plasma for 450 mm semiconductor wafer processing

International Nuclear Information System (INIS)

Lee, Ho-Jun; Kim, Yun-Gi

2012-01-01

The characteristics of weakly magnetized inductively coupled plasma (MICP) are investigated using a self-consistent simulation based on the drift–diffusion approximation with anisotropic transport coefficients. MICP is a plasma source utilizing the cavity mode of the low-frequency branch of the right-hand circularly polarized wave. The model system is 700 mm in diameter and has a 250 mm gap between the radio-frequency window and wafer holder. The model chamber size is chosen to verify the applicability of this type of plasma source to the 450 mm wafer process. The effects of electron density distribution and external axial magnetic field on the propagation properties of the plasma wave, including the wavelength modulation and refraction toward the high-density region, are demonstrated. The restricted electron transport and thermal conductivity in the radial direction due to the magnetic field result in small temperature gradient along the field lines and off-axis peak density profile. The calculated impedance seen from the antenna terminal shows that MICP has a resistance component that is two to threefold higher than that of ICP. This property is practically important for large-size, low-pressure plasma sources because high resistance corresponds to high power-transfer efficiency and stable impedance matching characteristics. For the 0.665 Pa argon plasma, MICP shows a radial density uniformity of 6% within 450 mm diameter, which is much better than that of nonmagnetized ICP.

Jeans instability in collisional strongly coupled dusty plasma with radiative condensation and polarization force

International Nuclear Information System (INIS)

Prajapati, R. P.; Bhakta, S.; Chhajlani, R. K.

2016-01-01

The influence of dust-neutral collisions, polarization force, and electron radiative condensation is analysed on the Jeans (gravitational) instability of partially ionized strongly coupled dusty plasma (SCDP) using linear perturbation (normal mode) analysis. The Boltzmann distributed ions, dynamics of inertialess electrons, charged dust and neutral particles are considered. Using the plane wave solutions, a general dispersion relation is derived which is modified due to the presence of dust-neutral collisions, strong coupling effect, polarization force, electron radiative condensation, and Jeans dust/neutral frequencies. In the long wavelength perturbations, the Jeans instability criterion depends upon strong coupling effect, polarization interaction parameter, and thermal loss, but it is independent of dust-neutral collision frequency. The stability of the considered configuration is analysed using the Routh–Hurwitz criterion. The growth rates of Jeans instability are illustrated, and stabilizing influence of viscoelasticity and dust-neutral collision frequency while destabilizing effect of electron radiative condensation, polarization force, and Jeans dust-neutral frequency ratio is observed. This work is applied to understand the gravitational collapse of SCDP with dust-neutral collisions.

Extraction inductively coupled plasma-optical emission spectrometry (ICP-OES). Determination of traces of phosphorus in tungsten

International Nuclear Information System (INIS)

Bauer, G.; Wegscheider, W.; Mueller, K.

1989-01-01

A method for the separation and preconcentration of traces of phosphorus from tungsten was developed. Solid phase extraction of the phosphovanadomolybdate complex performed on a micro-column was applied. Phosphorus was determined by optical emission spectroscopy (OES) with inductively coupled plasma (ICP) excitation. A limit of detection of 0,4 μg/g P with respect to the solid phase is obtained. By directly coupling the extraction/elution step to the ICP instrument a detection limit of 0,06 μg/g P in W was achieved. Besides, the complexity of spectral evaluation in ICP-OES determinations of traces in spectralline-rich matrices is discussed. (Authors)

Removal of model proteins by means of low-pressure inductively coupled plasma discharge

International Nuclear Information System (INIS)

Kylian, O; Rauscher, H; Gilliland, D; Bretagnol, F; Rossi, F

2008-01-01

Surgical instruments are intended to come into direct contact with the patients' tissues and thus interact with their first immune defence system. Therefore they have to be cleaned, sterilized and decontaminated, in order to prevent any kind of infections and inflammations or to exclude the possibility of transmission of diseases. From this perspective, the removal of protein residues from their surfaces constitutes new challenges, since certain proteins exhibit high resistance to commonly used sterilization and decontamination techniques and hence are difficult to remove without inducing major damages to the object treated. Therefore new approaches must be developed for that purpose and the application of non-equilibrium plasma discharges represents an interesting option. The possibility to effectively remove model proteins (bovine serum albumin, lysozyme and ubiquitin) from surfaces of different materials (Si wafer, glass, polystyrene and gold) by means of inductively coupled plasma discharges sustained in different argon containing mixtures is demonstrated and discussed in this paper

Removal of model proteins by means of low-pressure inductively coupled plasma discharge

Energy Technology Data Exchange (ETDEWEB)

Kylian, O; Rauscher, H; Gilliland, D; Bretagnol, F; Rossi, F [European Commission, Joint Research Centre, Institute for Health and Consumer Protection, Via E Fermi 2749, 21027 Ispra (Italy)], E-mail: francois.rossi@jrc.it

2008-05-07

Surgical instruments are intended to come into direct contact with the patients' tissues and thus interact with their first immune defence system. Therefore they have to be cleaned, sterilized and decontaminated, in order to prevent any kind of infections and inflammations or to exclude the possibility of transmission of diseases. From this perspective, the removal of protein residues from their surfaces constitutes new challenges, since certain proteins exhibit high resistance to commonly used sterilization and decontamination techniques and hence are difficult to remove without inducing major damages to the object treated. Therefore new approaches must be developed for that purpose and the application of non-equilibrium plasma discharges represents an interesting option. The possibility to effectively remove model proteins (bovine serum albumin, lysozyme and ubiquitin) from surfaces of different materials (Si wafer, glass, polystyrene and gold) by means of inductively coupled plasma discharges sustained in different argon containing mixtures is demonstrated and discussed in this paper.

Dust-Plasma Interactions

International Nuclear Information System (INIS)

Rosenberg, Marelene

2005-01-01

Our theoretical research on dust-plasma interactions has concentrated on three main areas: (a)studies of grain charging and applications; (b) waves and instabilities in weakly correlated dusty plasma with applications to space and laboratory plasmas; (c) waves in strongly coupled dusty plasmas.

Investigation of Capacitively Coupled Argon Plasma Driven by Dual-Frequency with Different Frequency Configurations

International Nuclear Information System (INIS)

Yu Yiqing; Xin Yu; Ning Zhaoyuan; Lu Wenqi

2011-01-01

Low pressure argon dual-frequency (DF) capacitively coupled plasma (CCP) is generated by using different frequency configurations, such as 13.56/2, 27/2, 41/2, and 60/2 MHz. Characteristics of the plasma are investigated by using a floating double electrical probe and optical emission spectroscopy (OES). It is shown that in the DF-CCPs, the electron temperature T e decreases with the increase in exciting frequency, while the onset of 2 MHz induces a sudden increase in T e and the electron density increases basically with the increase in low frequency (LF) power. The intensity of 750.4 nm emission line increases with the LF power in the case of 13.56/2 MHz, while different tendencies of line intensity with the LF power appear for other configurations. The reason for this is also discussed.

Bulk plasma fragmentation in a C4F8 inductively coupled plasma: A hybrid modeling study

International Nuclear Information System (INIS)

Zhao, Shu-Xia; Zhang, Yu-Ru; Gao, Fei; Wang, You-Nian; Bogaerts, Annemie

2015-01-01

A hybrid model is used to investigate the fragmentation of C 4 F 8 inductive discharges. Indeed, the resulting reactive species are crucial for the optimization of the Si-based etching process, since they determine the mechanisms of fluorination, polymerization, and sputtering. In this paper, we present the dissociation degree, the density ratio of F vs. C x F y (i.e., fluorocarbon (fc) neutrals), the neutral vs. positive ion density ratio, details on the neutral and ion components, and fractions of various fc neutrals (or ions) in the total fc neutral (or ion) density in a C 4 F 8 inductively coupled plasma source, as well as the effect of pressure and power on these results. To analyze the fragmentation behavior, the electron density and temperature and electron energy probability function (EEPF) are investigated. Moreover, the main electron-impact generation sources for all considered neutrals and ions are determined from the complicated C 4 F 8 reaction set used in the model. The C 4 F 8 plasma fragmentation is explained, taking into account many factors, such as the EEPF characteristics, the dominance of primary and secondary processes, and the thresholds of dissociation and ionization. The simulation results are compared with experiments from literature, and reasonable agreement is obtained. Some discrepancies are observed, which can probably be attributed to the simplified polymer surface kinetics assumed in the model

Plutonium bioassay by inductively coupled plasma mass spectrometry ICP/MS

International Nuclear Information System (INIS)

Wyse, E.J.; Fisher, D.R.

1993-04-01

The determination of plutonium in urine poses several analytical challenges, e.g., detectability, matrix, etc. We have investigated the feasibility of analyzing plutonium in processed urine by inductively coupled plasma mass spectrometry (ICP/MS). The urine samples are first spiked with 244 Pu as a tracer and internal standard, then processed by co-precipitation and column chromatography using TRU-Spec trademark, an extraction resin. By enhancing ICP/MS detection capabilities via improved sample introduction and data acquisition efficiencies, an instrumental detection limit of 5 to 50 fg (0.3 to 3 fCi for 239 pu) is typically obtained, depending on the desired degree of quantitation. A brief summary of the analytical method as well as the basis for measuring radionuclides by ICP/MS are submitted; the separation procedure, methods of sample introduction, and data acquisition techniques are then highlighted

Waves in Space Plasmas Program

Science.gov (United States)

Fredricks, R. W.; Taylor, W. W. L.

1981-01-01

The Waves in Space Plasmas (WISP) program is a joint international effort involving instrumentation to be designed and fabricated by funding from NASA and the National Research Council of Canada. The instrumentation, with a tentatively planned payload for 1986, can be used to perturb the plasma with radio waves to solve problems in ionospheric, atmospheric, magnetospheric, and plasma physics. Among the ionospheric and plasma phenomena to be investigated using WISP instrumentation are VLF wave-particle interactions; ELF/VLF propagation; traveling ionospheric disturbances and gravity wave coupling; equatorial plasma bubble phenomena; plasma wave physics such as mode-coupling, dispersion, and instabilities; and plasma physics of the antenna-plasma interactions.

Waves in Space Plasmas Program

International Nuclear Information System (INIS)

Fredricks, R.W.; Taylor, W.W.L.

1981-01-01

The Waves in Space Plasmas (WISP) program is a joint international effort involving instrumentation to be designed and fabricated by funding from NASA and the National Research Council of Canada. The instrumentation, with a tentatively planned payload for 1986, can be used to perturb the plasma with radio waves to solve problems in ionospheric, atmospheric, magnetospheric, and plasma physics. Among the ionospheric and plasma phenomena to be investigated using WISP instrumentation are VLF wave-particle interactions, ELF/VLF propagation, traveling ionospheric disturbances and gravity wave coupling, equatorial plasma bubble phenomena, plasma wave physics such as mode-coupling, dispersion, and instabilities, and plasma physics of the antenna-plasma interactions

The prognostic value of the suPARnosticTM ELISA assay in HIV-1 infected individuals is not affected by uPAR promoter polymorphisms

DEFF Research Database (Denmark)

Schneider, Uffe Vest; Nielsen, Rikke Lyngaa; Pedersen, Court

2007-01-01

BACKGROUND: High blood levels of soluble urokinase Plasminogen Activator Receptor (suPAR) are associated with poor outcomes in human immunodeficiency-1 (HIV-1) infected individuals. Research on the clinical value of suPAR in HIV-1 infection led to the development of the suPARnosticTM assay...... for commercial use in 2006. The aim of this study was to: 1) Evaluate the prognostic value of the new suPARnosticTM assay and 2) Determine whether polymorphisms in the active promoter of uPAR influences survival and/or suPAR values in HIV-1 patients who are antiretroviral therapy (ART) naive. METHODS: DNA...... and an A to G transition at -465 comparative to the transcription start site. These promoter transitions did not influence neither the suPAR levels nor patient survival. CONCLUSION: Plasma suPAR levels, as measured by the suPARnosticTM assay, were strongly predictive of survival in ART-naive HIV-1 infected...

Investigation of a measure of robustness in inductively coupled plasma mass spectrometry

Science.gov (United States)

Makonnen, Yoseif; Beauchemin, Diane

2015-01-01

In industrial/commercial settings where operators often have minimal expertise in inductively coupled plasma (ICP) mass spectrometry (MS), there is a prevalent need for a response factor indicating robust plasma conditions, which is analogous to the Mg II/Mg I ratio in ICP optical emission spectrometry (OES), whereby a Mg II/Mg I ratio of 10 constitutes robust conditions. While minimizing the oxide ratio usually corresponds to robust conditions, there is no specific target value that is widely accepted as indicating robust conditions. Furthermore, tuning for low oxide ratios does not necessarily guarantee minimal matrix effects, as they really address polyatomic interferences. From experiments, conducted in parallel for both MS and OES, there were some element pairs of similar mass and very different ionization potential that were exploited for such a purpose, the rationale being that, if these elements were ionized to the same extent, then that could be indicative of a robust plasma. The Be II/Li I intensity ratio was directly related to the Mg II/Mg I ratio in OES. Moreover, the 9Be+/7Li+ ratio was inversely related to the CeO+/Ce+ and LaO+/La+ oxide ratios in MS. The effects of different matrices (i.e. 0.01-0.1 M Na) were also investigated and compared to a conventional argon plasma optimized for maximum sensitivity. The suppression effect of these matrices was significantly reduced, if not eliminated in the case of 0.01 M Na, when the 9Be+/7Li+ ratio was around 0.30 on the Varian 820 MS instrument. Moreover, a very similar ratio (0.28) increased robustness to the same extent on a completely different ICP-MS instrument (PerkinElmer NEXION). Much greater robustness was achieved using a mixed-gas plasma with nitrogen in the outer gas and either nitrogen or hydrogen as a sheathing gas, as the 9Be+/7Li+ ratio was then around 1.70. To the best of our knowledge, this is the first report on using a simple analyte intensity ratio, 9Be+/7Li+, to gauge plasma robustness.

Cobalamin speciation using reversed-phase micro-high-performance liquid chromatography interfaced to inductively coupled plasma mass spectrometry

International Nuclear Information System (INIS)

Yanes, Enrique G.; Miller-Ihli, Nancy J.

2004-01-01

Micro-high-performance liquid chromatography interfaced to inductively coupled plasma mass spectrometry was optimized for the determination and separation of a mixture of cobalt containing species. Four cobalamin species (cyanocobalamin, hydroxocobalamin, methylcobalamin, and 5'-deoxyadenosylcobalamin) representing the various forms of vitamin B12 as well as the harmful corrinoid analogue cobinamide dicyanide were separated using reversed-phase microcapillary chromatography with columns containing C18 packing material with a 2-μm particle size. Selection of organic solvents for the separation took into consideration compatibility with the inductively coupled plasma mass spectrometer being used for element specific detection. Optimized method conditions included use of a methanol gradient and make-up solution for the nebulizer. Some issues associated with dead volume were overcome by the extension of the gradient program. The total analysis time was 52 min. The column-to-column variability was evaluated and was found to be very reasonable (9% RSD on average), confirming that this method is rugged and that the technology should be easily transferred to other laboratories

Behavior of microorganisms in drinking water treatment by inductively coupled plasma system: Case study in ground water

Science.gov (United States)

Desmiarti, Reni; Hazmi, Ariadi; Martynis, Munas; Sutopo, Ulung Muhammad; Li, Fusheng

2018-02-01

Pathogenic bacteria, such as total coliforms (TC), fecal coliforms (FC) and other coliforms (OC), were removed from groundwater by inductively coupled plasma system treatment in continuous flow experiments. The objective of this study is to investigate the effect of flowrate and frequency on the behavior of microorganisms in drinking water treatment using inductively coupled plasma system (ICPS). The results showed that after 120 minutes of ICPS treatment, the removal efficiency with respect to TC, FC and OC decreased with increasing flowrate. The removal efficiency of FC was achieved at 100% in all runs. Compared to FC, the removal efficiencies with respect to TC and FC were lower than those with respect to TC and OC in the following order: FC >OC> TC. The disinfection yield of TC and OC significantly increased when the removal efficiency increased. The electromagnetic flux varied from 8.08±0.46 to 10.54±0.19 W/cm2. The results in the present work can be used to design a new technology for drinking water treatment to remove all pathogenic bacteria without using hazardous chemicals.

Elemental labelling combined with liquid chromatography inductively coupled plasma mass spectrometry for quantification of biomolecules: A review

Science.gov (United States)

Kretschy, Daniela; Koellensperger, Gunda; Hann, Stephan

2012-01-01

This article reviews novel quantification concepts where elemental labelling is combined with flow injection inductively coupled plasma mass spectrometry (FI-ICP-MS) or liquid chromatography inductively coupled plasma mass spectrometry (LC–ICP-MS), and employed for quantification of biomolecules such as proteins, peptides and related molecules in challenging sample matrices. In the first sections an overview on general aspects of biomolecule quantification, as well as of labelling will be presented emphasizing the potential, which lies in such methodological approaches. In this context, ICP-MS as detector provides high sensitivity, selectivity and robustness in biological samples and offers the capability for multiplexing and isotope dilution mass spectrometry (IDMS). Fundamental methodology of elemental labelling will be highlighted and analytical, as well as biomedical applications will be presented. A special focus will lie on established applications underlining benefits and bottlenecks of such approaches for the implementation in real life analysis. Key research made in this field will be summarized and a perspective for future developments including sophisticated and innovative applications will given. PMID:23062431

Effect of low-damage inductively coupled plasma on shallow nitrogen-vacancy centers in diamond

Energy Technology Data Exchange (ETDEWEB)

Fávaro de Oliveira, Felipe; Momenzadeh, S. Ali; Wang, Ya; Denisenko, Andrej, E-mail: a.denisenko@physik.uni-stuttgart.de [3. Institute of Physics, Research Center SCoPE and IQST, University of Stuttgart, 70569 Stuttgart (Germany); Konuma, Mitsuharu [Max Planck Institute for Solid State Research, 70569 Stuttgart (Germany); Markham, Matthew; Edmonds, Andrew M. [Element Six Innovation, Harwell Oxford, Didcot, Oxfordshire OX11 0QR (United Kingdom); Wrachtrup, Jörg [3. Institute of Physics, Research Center SCoPE and IQST, University of Stuttgart, 70569 Stuttgart (Germany); Max Planck Institute for Solid State Research, 70569 Stuttgart (Germany)

2015-08-17

Near-surface nitrogen-vacancy (NV) centers in diamond have been successfully employed as atomic-sized magnetic field sensors for external spins over the last years. A key challenge is still to develop a method to bring NV centers at nanometer proximity to the diamond surface while preserving their optical and spin properties. To that aim we present a method of controlled diamond etching with nanometric precision using an oxygen inductively coupled plasma process. Importantly, no traces of plasma-induced damages to the etched surface could be detected by X-ray photoelectron spectroscopy and confocal photoluminescence microscopy techniques. In addition, by profiling the depth of NV centers created by 5.0 keV of nitrogen implantation energy, no plasma-induced quenching in their fluorescence could be observed. Moreover, the developed etching process allowed even the channeling tail in their depth distribution to be resolved. Furthermore, treating a {sup 12}C isotopically purified diamond revealed a threefold increase in T{sub 2} times for NV centers with <4 nm of depth (measured by nuclear magnetic resonance signal from protons at the diamond surface) in comparison to the initial oxygen-terminated surface.

Atlas of Atomic Spectral Lines of Neptunium Emitted by an Inductively Coupled Plasma

International Nuclear Information System (INIS)

DeKalb, E.L.; Edelson, M.C.

1987-01-01

Optical emission spectra from high-purity Np-237 were generated with a glovebox-enclosed inductively coupled plasma (ICP) source. Spectra covering the 230-700 nm wavelength range are presented along with general commentary on the methodology used in collecting the data. The Ames Laboratory Nuclear Safeguards and Security Program has been charged with the task of developing optical spectroscopic methods to analyze the composition of spent nuclear fuels. Such materials are highly radioactive even after prolonged 'cooling' and are chemically complex. Neptunium (Np) is a highly toxic by-product of nuclear power generation and is found, in low abundance, in spent nuclear fuels. This atlas of the optical emission spectrum of Np, as produced by an inductively coupled plasma (ICP) spectroscopic source, is part of a general survey of the ICP emission spectra of the actinide elements. The ICP emission spectrum of the actinides originates almost exclusively from the electronic relaxation of excited, singly ionized species. Spectral data on the Np ion emission spectrum (i.e., the Np II spectrum) have been reported by Tomkins and Fred (1) and Haaland (2). Tomkins and Fred excited the Np II spectrum with a Cu spark discharge and identified 114 Np lines in the 265.5 - 436.3 nm spectral range. Haaland, who corrected some spectral line misidentifications in the work of Tomkins and Fred, utilized an enclosed Au spark discharge to excite the Np II spectrum and reported 203 Np lines within the 265.4 - 461.0 nm wavelength range.

Microwave power coupling in a surface wave excited plasma

Directory of Open Access Journals (Sweden)

Satyananda Kar

2015-01-01

Full Text Available In recent decades, different types of plasma sources have been used for various types of plasma processing, such as, etching and thin film deposition. The critical parameter for effective plasma processing is high plasma density. One type of high density plasma source is Microwave sheath-Voltage combination Plasma (MVP. In the present investigation, a better design of MVP source is reported, in which over-dense plasma is generated for low input microwave powers. The results indicate that the length of plasma column increases significantly with increase in input microwave power.